ASPHALT FINISHER AND CONSTRUCTION ASSISTANCE SYSTEM FOR ASPHALT FINISHER

Abstract

 An asphalt finisher includes a tractor, a hopper installed on a front side of the tractor, a conveyor that conveys a paving material inside the hopper to a rear side of the tractor, a screw that lays and spreads the paving material conveyed by the conveyor and scattered on a road surface in a vehicle width direction, and a screed device that lays and levels the paving material laid and spread by the screw on a rear side of the screw. An operation of a transport vehicle is synchronized to correspond to an operation of the asphalt finisher.

Description

Technical Field

[0001] The present invention relates to an asphalt finisher and a construction assistance system for an asphalt finisher.

Background Art

[0002] In the related art, an asphalt finisher is known which includes a tractor, a hopper installed on a front side of the tractor to receive a paving material, a conveyor that feeds the paving material inside the hopper to a rear side of the tractor, a screw that lays and spreads the paving material fed by the conveyor on the rear side of the tractor, and a screed that lays and levels the paving material laid and spread by the screw on a rear side of the screw.

[0003]  When the asphalt finisher carries out construction, a transport vehicle (for example, a dump truck) that transports the paving material exists in front of the asphalt finisher. Then, the paving material is supplied to the asphalt finisher from the transport vehicle. The asphalt finisher needs to continuously carry out the construction. Therefore, after the transport vehicle reaches a position where the paving material can be supplied to the asphalt finisher, the transport vehicle needs to move forward together with the asphalt finisher so that the asphalt finisher continuously carries out the construction.

Citation List

Patent Literature

[0004] [PTL 1] International Publication No. 2017/010541

Summary of Invention

Technical Problem

[0005] Usually, an operator of the asphalt finisher sounds a horn to notify a driver of the transport vehicle of a start timing of the asphalt finisher. The driver of the transport vehicle controls starting and stopping of the transport vehicle while listening to the horn and confirming a movement of the asphalt finisher.

[0006] While the asphalt finisher carries out the construction, when a load of the transport vehicle on the asphalt finisher (load applied to the asphalt finisher when the transport vehicle in contact with a front end of the asphalt finisher is pushed forward) fluctuates, there is a possibility that quality of a road surface of a constructed road may be degraded. Therefore, it is preferable to control the transport vehicle so that the asphalt finisher and the transport vehicle do not come into contact with each other.

[0007] In view of the above-described circumstances, it is desirable to provide an asphalt finisher which can appropriately control a transport vehicle in accordance with a situation of the asphalt finisher.

Solution to Problem

[0008] According to an aspect of the present invention, there is provided an asphalt finisher including a tractor, a hopper installed on a front side of the tractor, a conveyor that conveys a paving material inside the hopper to a rear side of the tractor, a screw that lays and spreads the paving material conveyed by the conveyor and scattered on a road surface in a vehicle width direction, and a screed device that lays and levels the paving material laid and spread by the screw on a rear side of the screw. An operation of a transport vehicle is synchronized to correspond to an operation of the asphalt finisher.

Advantageous Effects of Invention

[0009] According to the aspect of the present invention, the asphalt finisher can prevent quality degradation of a pavement surface by synchronizing the operation of the transport vehicle to correspond to the operation of the asphalt finisher.

Brief Description of Drawings

[0010] 

Fig. 1A is a left side view illustrating an asphalt finisher and a dump truck which are examples of a road paving machine according to a first embodiment.

Fig. 1B is a top view illustrating the asphalt finisher and the dump truck which are the examples of the road paving machine according to the first embodiment.

Fig. 2 is a block diagram illustrating a configuration of the asphalt finisher and the dump truck according to the first embodiment.

Fig. 3 is a view illustrating a process procedure performed by the asphalt finisher according to the first embodiment.

Fig. 4 is a top view of a construction site, illustrating a first movement path and a second movement path which are generated by a path generation unit for constructing a curved part of a road.

Fig. 5A is a view illustrating a case where each inter-vehicle component distance between a rear wheel of the dump truck and a roller of the asphalt finisher according to the first embodiment is a distance "0".

Fig. 5B is a view illustrating a case where each inter-vehicle component distance between the rear wheel of the dump truck and the roller of the asphalt finisher according to the first embodiment is a predetermined distance "A".

Fig. 5C is a conceptual diagram illustrating a case where each inter-vehicle component distance between the rear wheel of the dump truck and the roller of the asphalt finisher according to the first embodiment is a reference distance "A/2".

Description of Embodiments

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, the same reference numerals will be assigned to the same or corresponding configurations, and description thereof may be omitted.

(First Embodiment)

[0012] Figs. 1A and 1B are views illustrating an asphalt finisher 100 and a dump truck 200, which are examples of a road paving machine according to a first embodiment. Specifically, Fig. 1A is a left side view, and Fig. 1B is a top view. Figs. 1A and 1B illustrate an example in which the dump truck 200 approaches the asphalt finisher 100 while moving rearward.

[0013] The asphalt finisher 100 is configured to mainly include a tractor 1, a hopper 2, and a screed device 3.

[0014] The screed device 3 is a mechanism for laying and leveling a paving material. In the present embodiment, the screed device 3 is a floating screed device towed by the tractor 1, and is connected to the tractor 1 via a leveling arm 3a.

[0015] The hopper 2 is provided on a front side of the tractor 1 as a mechanism for receiving the paving material. The hopper 2 of the present embodiment has a mechanism that can be opened and closed in a vehicle width direction by a hopper cylinder 2a while movable mechanism portions 81a and 81b serve as axes. Then, when the asphalt finisher 100 is about to run out of the paving material (for example, an asphalt mixture) inside the hopper 2, the asphalt finisher 100 can bring the hopper 2 into a fully opened state, and can receive the paving material (for example, the asphalt mixture) from a loading platform 201 of the dump truck 200 serving as a paving material transport vehicle. Then, in a state where the dump truck 200 is in contact with the asphalt finisher 100, the paving material is supplied to the hopper 2 from the loading platform 201 of the dump truck 200.

[0016] In addition, even when the paving material is received from the loading platform 201 of the dump truck 200, the asphalt finisher 100 continues traveling (construction) while advancing in a traveling direction together with the dump truck 200. Specifically, a conveyor conveys the paving material received inside the hopper 2 to a rear side of the tractor 1. A screw lays and spreads the paving material conveyed by the conveyor and scattered on a road surface in the vehicle width direction. The screed device 3 lays and levels the paving material laid and spread by the screw on a rear side of the screw.

[0017] After the paving material is received from the loading platform 201 of the dump truck 200, an operator of the asphalt finisher 100 can put the paving material supplied to the hopper 2 on the conveyor by gradually closing the hopper 2. Thereafter, when the paving material supplied to the hopper 2 is conveyed rearward and the paving material inside the hopper 2 substantially runs out, the operator opens the hopper 2. Then, in a stage where the hopper 2 is in the fully opened state again, the hopper 2 can receive the paving material from the dump truck 200. Therefore, it is preferable that a driver of the dump truck 200 brings the dump truck 200 close to the asphalt finisher 100 after confirming that the hopper 2 is in the fully opened state.

[0018] Furthermore, the asphalt finisher 100 includes a roller 2b. The roller 2b is installed in front of the hopper 2. The roller 2b is configured to be capable of coming into contact with a rear wheel 202 of the dump truck 200, and when the rear wheel 202 of the dump truck 200 is in contact with the roller 2b, the roller 2b can rotate together with the rear wheel 202.

[0019] The tractor 1 is a mechanism for causing the asphalt finisher 100 to travel. In the present embodiment, the tractor 1 moves the asphalt finisher 100 in such a manner that a traveling hydraulic motor is used to rotate front wheels and rear wheels. The traveling hydraulic motor rotates by receiving hydraulic oil supply from a hydraulic source. The tractor 1 may include a crawler instead of the wheels.

[0020] In addition, the tractor 1 is equipped with a controller 30, a wireless communication device 40, a GPS module 50, a main monitor 60, a driving seat 61, an imaging device 62, and an audio output device 63. Specifically, a cab including the main monitor 60 and the driving seat 61 is installed on an upper surface of the tractor 1. The imaging device 62 and the audio output device 63 are installed at the center of the front end of the upper surface of the tractor 1.

[0021] The wireless communication device 40 directly performs short-range wireless communication with a device existing around the asphalt finisher 100, for example, such as a dump truck 200. In the present embodiment, for example, it is conceivable to use Wi-Fi (registered trademark) as a wireless communication standard of the wireless communication device 40. The wireless communication of the present embodiment is not limited to a method using the Wi-Fi (registered trademark), and wireless LAN or Bluetooth (registered trademark) may be used.

[0022] The GPS module 50 is an example of a Global Navigation Satellite System (GNSS) module, and receives position information indicating a result of two-dimensional positioning obtained by a Global Positioning System (GPS). The position information includes information representing a position of the asphalt finisher 100 in latitude and longitude. In the present embodiment, although an example will be described in which the GPS is used as a position information acquisition method, the present invention is not limited to the position information acquisition method, and other well-known methods may be used.

[0023] The main monitor 60 is a device that displays various information to the operator of the asphalt finisher 100. In the present embodiment, the main monitor 60 is a liquid crystal display, and can display various information in accordance with a command from the controller 30. In addition, the main monitor 60 includes an input device 60a that receives an operation input of the operator of the asphalt finisher 100.

[0024] The imaging device 62 is a device that acquires an image of a space in front of the asphalt finisher 100. In the present embodiment, the imaging device 62 is a camera, and outputs the acquired image to the controller 30. The imaging device 62 may be a range image camera, an infrared camera, or a stereo camera. In the present embodiment, an example in which the imaging device 62 is used as an example of a device capable of recognizing a space will be described. However, in the present embodiment, the space recognition device is not limited to the imaging device 62. That is, any space recognition device may be used as long as the space can be recognized based on the asphalt finisher 100, and for example, a laser sensor may be used.

[0025] The imaging device 62 (example of a detection device) according to the present embodiment images a space inside an imaging region RA1 (example of a detection range) existing in front of the asphalt finisher 100 and illustrated by a one-dot chain line in Figs. 1A and 1B. Then, the imaging device 62 outputs image information (example of detection information) relating to the captured image to the controller 30. In examples illustrated in Figs. 1A and 1B, the imaging device 62 can image the dump truck 200 existing inside the imaging region RA1.

[0026] The audio output device 63 is a device that outputs audio toward a periphery of the asphalt finisher 100. In the present embodiment, the audio output device 63 is a speaker that outputs audio forward of the asphalt finisher 100, and can output an alarm in accordance with a command from the controller 30. The audio output device 63 may output an audio message.

[0027] The controller 30 is a control device that controls the asphalt finisher 100. For example, the controller 30 is configured to include, a computer, and has a CPU, an internal memory, and a storage medium. The controller 30 performs various types of control by causing the CPU to execute a program stored in the storage medium.

[0028] The controller 30 can assist a driving operation of the asphalt finisher 100 by using Advanced driver-assistance systems (ADAS), based on image information received from the imaging device 62 and detection signals received from various detection sensors (not illustrated). A driving operation assistance system used by the controller 30 according to the present embodiment is not limited to a driving operation system using the ADAS, and may be another driving operation assistance system. For example, the controller 30 may use Autonomous Driving (AD). Furthermore, the controller 30 may use any system as long as the system can perform movement control of the asphalt finisher 100 along a movement path generated in advance.

[0029] The dump truck 200 is configured to include the loading platform 201, a hoist cylinder (not illustrated), a first imaging device 261, a second imaging device 262, a controller 230, and a wireless communication device 240. The loading platform 201 can be equipped with the paving material to be supplied to the hopper 2 of the asphalt finisher 100. The hoist cylinder is a mechanism that tilts the loading platform 201 rearward, and expands and contracts in accordance with a command from the controller 230. In this manner, the hoist cylinder switches between a tilted state where the loading platform 201 is tilted rearward and a horizontal state where the loading platform 201 is on a horizontal level.

[0030] For example, the first imaging device 261 is a device provided in the vicinity of an emblem of the dump truck 200 to acquire an image of a space in front of the dump truck 200. The second imaging device 262 is a device that acquires the image of the space behind the dump truck 200. The first imaging device 261 and the second imaging device 262 according to the present embodiment are cameras, and output the acquired image to the controller 230. The first imaging device 261 and the second imaging device 262 may be range image cameras, infrared cameras, or stereo cameras. In the present embodiment, an example in which the first imaging device 261 and the second imaging device 262 are used as examples of devices capable of recognizing the space will be described. However, in the present embodiment, the space recognition device is not limited to the first imaging device 261 and the second imaging device 262. That is, any space recognition device may be used as long as the space can be recognized based on the dump truck 200, and for example, a laser sensor may be used.

[0031] The first imaging device 261 according to the present embodiment images a space inside an imaging region RT1 existing in front of the dump truck 200 and illustrated by a two-dot chain line in Figs. 1A and 1B. The first imaging device 261 outputs image information relating to the captured image to the controller 230.

[0032]  The second imaging device 262 according to the present embodiment images a space inside an imaging region RT2 existing behind the dump truck 200 and illustrated by a two-dot chain line in Figs. 1A and 1B. The second imaging device 262 outputs image information relating to the captured image to the controller 230.

[0033] The wireless communication device 240 performs wireless communication with a device existing around the dump truck 200, for example, such as the wireless communication device 40 of the asphalt finisher 100. In the present embodiment, for example, it is conceivable to use Wi-Fi (registered trademark) as the wireless communication standard of the wireless communication device 240. The wireless communication of the present embodiment is not limited to a method using the Wi-Fi (registered trademark), and wireless LAN or Bluetooth (registered trademark) may be used.

[0034] The controller 230 is a control device that controls the dump truck 200. For example, the controller 230 is configured to include a computer, and has a CPU, an internal memory, and a storage medium. The controller 230 performs various types of control by causing the CPU to execute a program stored in the storage medium.

[0035] The controller 230 according to the present embodiment can assist a driving operation of the dump truck 200 by using the ADAS, based on image information received from the first imaging device 261, image information received from the second imaging device 262, and detection signals received from various detection sensors (not illustrated). The driving operation assistance system used by the controller 230 according to the present embodiment is not limited to the driving operation system using the ADAS, and may be another driving operation assistance system. For example, AD may be used as the controller 230. Furthermore, the controller 230 may use any system as long as the system can perform movement control in accordance with a movement path or various control commands. The control command of the present embodiment is information indicating an instruction for performing the movement control of the vehicle (for example, the asphalt finisher 100 or the dump truck 200).

[0036] For example, the controller 230 according to the present embodiment realizes control for stopping the dump truck 200 in the vicinity of the hopper 2 of the asphalt finisher 100 by using parking assistance of the ADAS. In this case, the controller 230 of the present embodiment may receive a control command from the asphalt finisher 100 via the wireless communication device 240, and may perform drive control of the dump truck 200, based on the received control command.

[0037] When the dump truck 200 is positioned in the vicinity of the hopper 2 of the asphalt finisher 100, the asphalt finisher 100 is usually under construction. Therefore, after the dump truck 200 is positioned in the vicinity of the hopper 2 of the asphalt finisher 100, while the dump truck 200 supplies the paving material to the hopper 2 from the loading platform 201, the dump truck 200 needs to travel together with the asphalt finisher 100.

[0038] Therefore, the controller 30 of the asphalt finisher 100 according to the present embodiment controls to synchronize the operation of the dump truck 200 to correspond to the operation of the asphalt finisher 100.

[0039] In the present embodiment, the controller 30 of the asphalt finisher 100 generates a first movement path for the asphalt finisher 100 for moving the asphalt finisher 100 to pave a construction target region, based on a construction plan drawing. Then, the controller 30 controls the asphalt finisher 100 to move along the first movement path.

[0040] The construction plan drawing that can be stored in the storage medium of the controller 30 includes information indicating the construction target region of the asphalt finisher 100 in a reference coordinate system.

[0041] For example, the reference coordinate system used in the construction plan drawing is a world geodetic system. The world geodetic system is a three-dimensional orthogonal XYZ-coordinate system in which an origin is set at the center of gravity of the earth, an axis passing through an intersection point between the Greenwich meridian and the equator and the origin is set as a latitude (X-axis), an axis passing through an intersection point between the 90th meridian east and the equator and the origin is set as a longitude (Y-axis), and an axis passing through the north pole and the origin is set as a Z-axis. In other words, the construction plan drawing includes information indicating a construction target region in the three-dimensional orthogonal XYZ-coordinate system (world geodetic system).

[0042] In addition, the construction plan drawing may include various information relating to the construction target region. For example, the construction plan drawing may include information indicating a position of an obstacle existing in the construction target region. For example, as the obstacle, there is step difference information existing on the road surface. For example, the step difference information is information relating to a manhole existing on the road surface.

[0043] The asphalt finisher 100 acquires position information indicating the position of the asphalt finisher 100 in the latitude and the longitude via the GPS module 50. Therefore, the controller 30 of the asphalt finisher 100 can identify the position indicated by the position information acquired by the GPS module 50 on the construction plan drawing.

[0044] Based on the construction plan drawing, the controller 30 generates a second movement path for the dump truck 200 so that the dump truck 200 travels in a state where the loading platform 201 of the dump truck 200 and the hopper 2 of the asphalt finisher 100 are maintained in an overlapping state (in other words, in a synchronized state). Then, the controller 30 generates a control command instructing a steering angle and a speed of the dump truck 200 so that the dump truck 200 travels along the second movement path. Then, the controller 30 transmits the generated control command to the wireless communication device 240 of the dump truck 200 via the wireless communication device 40. In this manner, the controller 30 synchronizes the operation of the dump truck 200 to correspond to the operation of the asphalt finisher 100.

[0045] Fig. 2 is a block diagram illustrating a configuration of the asphalt finisher 100 and the dump truck 200 according to the present embodiment. As illustrated in Fig. 2, the dump truck 200 includes a first imaging device 261, a second imaging device 262, an input device 263, a controller 230, a wireless communication device 240, and a drive system controller 250. That is, the present embodiment adopts the following example. In the construction assistance system for the asphalt finisher including the asphalt finisher 100 and the dump truck 200, the controller 30 controls the operation of the dump truck 200 and the operation of the asphalt finisher 100 to be synchronized with each other.

[0046] The controller 230 generates a control command relating to drive control, based on image information from the first imaging device 261 (for example, provided in the vicinity of the emblem on the front surface of the dump truck 200), image information from the second imaging device 262 (for example, provided in a rear end part of the dump truck 200), and a control signal from a detection sensor (not illustrated). Then, the controller 230 outputs the generated control command to the drive system controller 250. In this manner, the controller 230 realizes the driving operation assistance using the ADAS. The drive system controller 250 controls a drive system and an engine of the dump truck 200 in accordance with a control command.

[0047] In addition, the controller 230 performs various types of control by receiving an operation from a driver via the input device 263.

[0048] When the control command is received from the asphalt finisher 100 via the wireless communication device 240, the controller 230 outputs the received control command to the drive system controller 250. In this manner, the dump truck 200 realizes the driving operation assistance using the ADAS in accordance with a request from the asphalt finisher 100.

[0049] In addition, the controller 230 may transmit the image information captured by the first imaging device 261 and the image information captured by the second imaging device 262 to the asphalt finisher 100 via the wireless communication device 240.

[0050] The asphalt finisher 100 includes the imaging device 62, the input device 60a, the controller 30, the drive system controller 55, and the wireless communication device 40. The drive system controller 55 controls the tractor 1 in accordance with the control command.

[0051] The controller 30 according to the present embodiment can perform the driving operation assistance using the Advanced driver-assistance systems (ADAS), based on the image information received from the imaging device 62 and the detection signals received from various detection sensors (not illustrated). In addition, the controller 30 according to the present embodiment is not limited to the driving operation assistance using the ADAS, and another driving operation assistance may be used. For example, the controller 30 may use Autonomous Driving (AD).

[0052] The controller 30 of the present embodiment receives an input of the construction plan drawing via a connection I/F (not illustrated) or the wireless communication device 40.

[0053]  Then, the controller 30 performs various types of control so that the asphalt finisher 100 and the dump truck 200 move in the construction target region, based on the construction plan drawing.

[0054] Each functional block included in the controller 30 illustrated in Fig. 2 is conceptual, and does not necessarily have to be physically configured as illustrated. All or a part of each functional block may be functionally or physically distributed or integrated in any unit. All or any part of each processing function performed in each functional block is realized by a program executed by the CPU. Alternatively, each functional block may be realized as hardware using a wired logic. As illustrated in Fig. 2, the controller 30 includes a dump truck identification information storage unit 31, an acquisition unit 32, a path generation unit 33, a detection unit 34, a determination unit 35, a command generation unit 36, and a communication control unit 37.

[0055] The dump truck identification information storage unit 31 is provided on a storage medium inside the controller 30. The dump truck identification information storage unit 31 stores information for the asphalt finisher 100 to identify the dump truck 200 serving as a communication target. For example, the dump truck identification information storage unit 31 stores number plate information of the dump truck 200 and identification information (for example, SSID) of the wireless communication device 240 mounted on the dump truck 200 in association with each other. In this manner, the controller 30 can identify the wireless communication device 240 serving as the communication target, based on the imaged number plate when the imaging device 62 images a rear part of the dump truck 200.

[0056] The acquisition unit 32 acquires image information captured by the imaging device 62. In addition, the acquisition unit 32 acquires operation information from the operator via the input device 60a.

[0057] In addition, the acquisition unit 32 acquires the construction plan drawing. For example, the acquisition unit 32 may acquire the construction plan drawing from a non-volatile storage medium connected via a connection I/F (for example, a USB I/F) (not illustrated). Furthermore, the acquisition unit 32 may acquire the construction plan drawing received by the communication control unit 37 from an external device via the wireless communication device 40.

[0058] The path generation unit 33 generates the movement paths of the asphalt finisher 100 and the dump truck 200, based on the construction plan drawing acquired by the acquisition unit 32. In the present embodiment, the movement path is generated after the construction plan drawing is acquired and before the asphalt finisher 100 starts the construction. In this manner, the path generation unit 33 can generate the movement path including a construction start position of the asphalt finisher 100.

[0059] The path generation unit 33 of the present embodiment generates the first movement path of the asphalt finisher 100 so that the whole construction target region indicated in the construction plan drawing can be constructed. Furthermore, the path generation unit 33 generates the second movement path of the dump truck 200 when the dump truck 200 travels in a state of being in contact with the asphalt finisher 100 traveling along the first movement path.

[0060] When a region having a step difference such as a manhole is included in the construction target region indicated in the construction plan drawing, the path generation unit 33 generates the first movement path and the second movement path so that the wheels of the asphalt finisher 100 and the dump truck 200 do not pass through the region having the step difference.

[0061] After the asphalt finisher 100 starts the construction, the detection unit 34 detects a transport vehicle such as the dump truck 200 existing in a front space of the asphalt finisher 100, based on the image information acquired from the imaging device 62. A technique for detecting the transport vehicle such as the dump truck 200 from an image indicated by the image information may be any technique including a known image processing technique. The detection unit 34 may detect other objects when detecting the transport vehicle from the image. For example, the other objects may include a load cone, a person (worker), and a small machine (rammer or tamper). In addition, the determination unit 35 may be configured to recognize (detect) an object existing around the asphalt finisher 100 (example of a work machine), based on the image information (output value) of the imaging device 62 serving as one type of the space recognition device. For example, the object serving as a recognition target includes the dump truck 200, a terrain shape (inclination or hole), an electric wire, an electric pole, a person, an animal, a vehicle, a construction machine, a building, a wall, a helmet, a safety vest, work clothes, or a predetermined mark on the helmet. In this way, the determination unit 35 may be configured to be capable of identifying at least one of a type, a position, and a shape of the object. For example, the determination unit 35 may be configured to be capable of distinguishing between the dump truck 200 and an object other than the dump truck.

[0062] The determination unit 35 determines various types of information, based on the image information (example of detection information) from the imaging device 62 (example of the detection device).

[0063] For example, the determination unit 35 determines the number plate information of the dump truck 200 existing in front of the asphalt finisher 100, based on the image information from the imaging device 62. In this manner, the determination unit 35 can identify the number plate information of the dump truck 200 serving as a control target.

[0064] Furthermore, the determination unit 35 may determine a distance between the dump truck 200 and the asphalt finisher 100. The determination unit 35 according to the present embodiment has a correspondence relationship between a size of the dump truck 200 captured in the image and a distance between the rear wheel 202 of the dump truck 200 and the roller 2b of the asphalt finisher 100. In this manner, the determination unit 35 can identify the distance between the rear wheel 202 of the dump truck 200 and the roller 2b of the asphalt finisher 100 from the image information acquired by the acquisition unit 32.

[0065] For example, the determination unit 35 determines whether or not the loading platform 201 of the dump truck 200 can be positioned at a designated position after the dump truck 200 is detected from the image captured by the imaging device 62. The designated position is a position of the loading platform 201 suitable for moving the paving material on the loading platform 201 into the hopper 2, and is a position partially overlapping the position of the hopper 2 of the asphalt finisher 100 in the vertical direction. In addition, the designated position is a position where the dump truck 200 moves in accordance with the movement of the asphalt finisher 100. Information relating to the designated position is typically stored in advance in the storage medium of the controller 30. In the present embodiment, the information relating to the designated position is information relating to a rectangular region having substantially the same size (area) as that of the loading platform 201 in a top view. In other words, the information relating to the designated position is information relating to a rectangular parallelepiped space having substantially the same size (volume) as that of the loading platform 201. Therefore, for example, "positioning the loading platform 201 of the dump truck 200 at the designated position" means causing the rectangular region corresponding to the actual loading platform 201 to coincide with the rectangular region corresponding to the designated position. A rectangular region ZN illustrated by a dotted line in Fig. 1B is an example of the rectangular region corresponding to the designated position.

[0066] The command generation unit 36 generates a control command for causing the asphalt finisher 100 to travel along the first movement path. Specifically, the command generation unit 36 of the present embodiment generates an acceleration command or a deceleration command of the asphalt finisher 100 for continuing the construction. In addition, the command generation unit 36 generates a control command relating to steering for moving along the first movement path, based on the first movement path, the acceleration command or the deceleration command, and the position information of the asphalt finisher 100 which is received from the GPS module 50. Furthermore, the command generation unit 36 may generate a control command for performing braking when necessary. Then, the command generation unit 36 outputs the generated control command to the drive system controller 55.

[0067] The command generation unit 36 of the present embodiment generates a control command for the asphalt finisher 100 so that the operation of the dump truck 200 and the operation of the asphalt finisher 100 are synchronized with each other. Specifically, a control command is generated so that both travel at a constant speed along the first movement path. In this manner, the operation of the dump truck 200 is easily synchronized with the operation of the asphalt finisher 100.

[0068] For example, the control command generated by the command generation unit 36 of the present embodiment includes a control command for steering so that the loading platform 201 of the dump truck 200 is positioned at the designated position. For example, other control commands include a control command for instructing the dump truck 200 to move rearward or stop so that the rear wheel 202 of the dump truck 200 is stopped in the vicinity of the roller 2b.

[0069] Furthermore, the command generation unit 36 generates a control command for causing the transport vehicle (for example, the dump truck 200) to travel along the second movement path after performing steering so that the loading platform 201 of the dump truck 200 is positioned at the designated position. Then, the command generation unit 36 outputs the generated control command to the communication control unit 37. For example, the control command for traveling along the second movement path is a steering command in a rightward direction or a leftward direction, a command to set a predetermined speed, an acceleration command, a deceleration command, or a braking command.

[0070] Specifically, the command generation unit 36 generates a control command to cause the dump truck 200 to travel at a speed determined, based on a speed of the asphalt finisher 100, after performing the steering so that the loading platform 201 of the dump truck 200 is positioned at the designated position. For example, as the speed determined based on the speed of the asphalt finisher 100, it is conceivable to adopt a speed substantially the same as a speed of the asphalt finisher 100. That is, since the dump truck 200 is caused to travel at substantially the same speed as that of the asphalt finisher 100, it is possible to maintain a state where the hopper 2 of the asphalt finisher 100 and the loading platform 201 of the dump truck 200 overlap each other in the vertical direction. However, even when both are instructed to travel at substantially the same speed, the command generation unit 36 may cause a position deviation due to a difference between the path followed by the hopper 2 of the asphalt finisher 100 and the path followed by the dump truck 200, or a speed deviation.

[0071] Therefore, the command generation unit 36 of the present embodiment generates a control command for acceleration or deceleration of the dump truck 200 to maintain the state where the hopper 2 of the asphalt finisher 100 and the loading platform 201 of the dump truck 200 overlap each other in the vertical direction.

[0072] In order to maintain the state where the hopper 2 of the asphalt finisher 100 and the loading platform 201 of the dump truck 200 overlap each other in the vertical direction, the command generation unit 36 according to the present embodiment performs control based on a relative position relationship between the asphalt finisher 100 and the dump truck 200.

[0073]  Furthermore, the command generation unit 36 generates a control command for dumping up the loading platform 201 of the dump truck 200 by controlling a hoist cylinder. The command generation unit 36 generates the control command for dumping up the loading platform 201 of the dump truck 200 after the loading platform 201 of the dump truck 200 is positioned at the designated position. In the present embodiment, the determination unit 35 may determine whether or not the loading platform 201 of the dump truck 200 is positioned at the designated position, based on the image information. Then, the command generation unit 36 generates the control command for dumping up the loading platform 201 of the dump truck 200 in accordance with a determination result. Furthermore, when an operation for dumping up the loading platform 201 of the dump truck 200 is received from the operator of the asphalt finisher 100 via the input device 60a, the command generation unit 36 may generate the control command for dumping up the loading platform 201 of the dump truck 200.

[0074] Furthermore, the command generation unit 36 generates the control command for dumping down the loading platform 201 of the dump truck 200 by controlling the hoist cylinder. In the present embodiment, after the paving material loaded on the loading platform 201 is completely supplied to the hopper 2, the command generation unit 36 generates the control command for dumping down the loading platform 201 of the dump truck 200. In the present embodiment, based on the image information, the determination unit 35 may determine whether or not the paving material loaded on the loading platform 201 of the dump truck 200 is emptied, in other words, whether or not the paving material is completely supplied. Then, the command generation unit 36 generates the control command for dumping down the loading platform 201 of the dump truck 200 in accordance with a determination result. Furthermore, when an operation for dumping down the loading platform 201 of the dump truck 200 is received from the operator of the asphalt finisher 100 via the input device 60a, the command generation unit 36 may generate the control command for dumping down the loading platform 201 of the dump truck 200.

[0075] The determination unit 35 identifies an inter-vehicle component distance, which is a distance between the rear wheel 202 of the dump truck 200 and the roller 2b of the asphalt finisher 100, from the image information acquired by the acquisition unit 32. Then, the command generation unit 36 of the present embodiment generates a control command for acceleration or deceleration of the dump truck 200 so that the inter-vehicle component distance falls within a range of a predetermined distance "A" from a distance "0". The predetermined distance "A" is a distance between the rear wheel 202 and the roller 2b in a situation where a rear end part of the loading platform 201 of the dump truck 200 and a tip part of the hopper 2 overlap each other in the vertical direction.

[0076] In other words, when the controller 30 can control the speed or the acceleration of the dump truck 200 so that the distance identified by the determination unit 35 falls within the range of the predetermined distance "A" from the distance "0", the controller 30 can maintain a state where the hopper 2 and the loading platform 201 overlap each other in the vertical direction. A specific control method will be described later.

[0077] In the present embodiment, an example in which the inter-vehicle component distance is controlled to fall within the range of the predetermined distance "A" from the distance "0" will be described. However, a control method used in the present embodiment is not limited to the above-described control method. That is, the controller 30 may use any control method as long as the command generation unit 36 generates the control command for controlling the speed or the acceleration of the dump truck 200, based on the inter-vehicle component distance so that the state where the hopper 2 and the loading platform 201 of the dump truck 200 overlap each other in the vertical direction can be maintained.

[0078] Furthermore, the command generation unit 36 generates a control command relating to steering for moving along the second movement path, based on the second movement path, the acceleration command or the deceleration command of the dump truck 200, and the position information of the dump truck 200. The position information of the dump truck 200 is calculated by the command generation unit 36 from the position information of the asphalt finisher 100 which is acquired from the GPS module 50 and the relative position relationship between the asphalt finisher 100 and the dump truck 200. The relative position relationship is obtained from the image information captured by the imaging device 62. Furthermore, the command generation unit 36 may generate a control command for braking the dump truck 200 when necessary. Then, the command generation unit 36 outputs the generated control command of the dump truck 200 to the wireless communication device 40.

[0079]  The present embodiment is configured to calculate the position information of the dump truck 200 from the position information of the asphalt finisher 100 which is acquired from the GPS module 50 and the relative position relationship between the asphalt finisher 100 and the dump truck 200. However, in the present embodiment, an acquisition method of the position information of the dump truck 200 is not limited to the above-described method. For example, the dump truck 200 may include a GPS module. Then, the controller 30 of the asphalt finisher 100 may acquire the position information acquired from the GPS module provided in the dump truck 200 by wireless communication between the asphalt finisher 100 and the dump truck 200.

[0080] The control command generated by the command generation unit 36 is not limited to the above-described command, and may be various other control commands. For example, when the control command generated by the command generation unit 36 may be a command that can be executed by the ADAS of the asphalt finisher 100, such as turning on/off the headlight of the asphalt finisher 100 or warning the operator of the asphalt finisher 100. Similarly, the control command generated by the command generation unit 36 may include a command that can be executed by the ADAS of the dump truck 200, such as turning on/off the headlight of the dump truck 200 or warning the driver of the dump truck 200.

[0081] The communication control unit 37 performs communication control with the transport vehicle such as the dump truck 200 via the wireless communication device 240. For example, the communication control unit 37 controls communication with the wireless communication device 240 indicated by identification information associated with the number plate information determined by the command generation unit 36. In this manner, the controller 30 can transmit the control command generated for the dump truck 200 to the dump truck 200. For example, the communication control unit 37 transmits a control command for moving the dump truck 200 along the second movement path generated by the command generation unit 36, to the wireless communication device 240.

[0082] Furthermore, the communication control unit 37 receives the image information relating to the image captured by the first imaging device 261 of the dump truck 200 via the wireless communication device 240.

[0083] The operator of the asphalt finisher 100 is less likely to visually confirm the traveling direction, when the dump truck 200 exists in front of the asphalt finisher 100. Therefore, the communication control unit 37 according to the present embodiment receives the image information relating to the image captured in front of the dump truck 200, which is captured by the first imaging device 261 of the dump truck 200. The communication control unit 37 outputs the received image information to the main monitor 60. In this manner, the operator of the asphalt finisher 100 can understand a situation in front of the dump truck 200.

[0084] Then, the determination unit 35 determines whether or not an obstacle exists on the movement path of the dump truck 200 and the asphalt finisher 100, based on the received image information. The obstacle to be determined may be any object. For example, the obstacle serving as a determination target is a scoop or a pylon.

[0085] Then, when the determination unit 35 determines that an obstacle exists, the audio output device 63 outputs warning information indicating that the obstacle exists, in accordance with an instruction from the determination unit 35. In this manner, the operator can recognize the presence or absence of the obstacle in the movement path. Furthermore, the operator can recognize a situation of the movement path by visually confirming the image information.

[0086] Fig. 3 is a view illustrating a process procedure performed by the asphalt finisher 100 according to the present embodiment. In the process procedure illustrated in Fig. 3, S301 and S302 are typically performed before the asphalt finisher 100 carries out the construction. The dump truck 200 may be driven by the driver, or may be automatically steered by the ADAS.

[0087] The acquisition unit 32 acquires the construction plan drawing (S301).

[0088] The path generation unit 33 generates the first movement path of the asphalt finisher 100 and the second movement path of the dump truck 200, based on the construction plan drawing acquired by the acquisition unit 32 (S302).

[0089] Then, the controller 30 starts movement control to move along the first movement path of the asphalt finisher 100 (S303).

[0090]  The acquisition unit 32 acquires the image information indicating the image captured by the imaging device 62 (S304) .

[0091] Then, the detection unit 34 determines whether or not the dump truck 200 exists in front of the asphalt finisher 100, based on the image information (S305). When the detection unit 34 determines that the dump truck 200 does not exist (S305: No), the controller 30 performs a process in S305 again after a predetermined time.

[0092] When the detection unit 34 determines that the dump truck 200 exists (S305: Yes), the communication control unit 37 identifies the identification information of the wireless communication device 240 from the number plate information of the dump truck 200. Then, the communication control unit 37 starts communication with the dump truck 200 equipped with the wireless communication device 240 indicated by the identified identification information (S306). In this manner, the controller 30 starts automatic control for the dump truck 200.

[0093] The communication control unit 37 transmits the control command generated by the command generation unit 36 to steer the dump truck 200 to position the loading platform 201 of the dump truck 200 at the designated position, to the wireless communication device 240 of the dump truck 200. (S307). In this manner, the dump truck 200 moves to a position where the loading platform 201 of the dump truck 200 overlaps the hopper 2 of the asphalt finisher 100 in the vertical direction. Thereafter, the dump truck 200 is movable together with the asphalt finisher 100.

[0094] The command generation unit 36 generates a speed control command of the dump truck 200, based on the speed of the asphalt finisher 100 (S308). For example, as the speed of the dump truck 200, it is conceivable to adopt the same speed as the speed of the asphalt finisher 100. That is, the controller 30 controls the dump truck 200 so that the speed of the dump truck 200 and the speed of the asphalt finisher 100 coincide with each other. In this manner, even when the distance between the dump truck 200 and the asphalt finisher 100 is changed, both can travel at the same speed.

[0095] The communication control unit 37 transmits the speed control command to the wireless communication device 240 of the dump truck 200 (S309).

[0096]  The acquisition unit 32 acquires the image information indicating the image captured by the imaging device 62 (S310). The acquisition unit 32 identifies the relative position information between the rear wheel 202 of the dump truck 200 and the roller 2b of the asphalt finisher 100 from the image information acquired in S310.

[0097] Furthermore, the acquisition unit 32 acquires the position information from the GPS module 50 (S311). In this manner, the controller 30 recognizes the position information (for example, in the world geodetic system) of the asphalt finisher 100. Furthermore, the acquisition unit 32 recognizes the position information (for example, in the world geodetic system) of the dump truck 200, from the position information (for example, in the world geodetic system) of the asphalt finisher 100 and the relative position information between the rear wheel 202 of the dump truck 200 and the roller 2b of the asphalt finisher 100.

[0098] Based on the above-described relative position information, the command generation unit 36 generates the control command relating to the speed of the dump truck 200 to maintain the overlapping state between the dump truck 200 and the asphalt finisher 100 (state where the loading platform 201 of the dump truck 200 overlaps the hopper 2 of the asphalt finisher 100 in the vertical direction) (S312). For example, the control command relating to the speed is a control command for causing the dump truck 200 to accelerate, decelerate, or maintain the speed. The control command relating to the speed of the present embodiment will be described later.

[0099] Furthermore, the command generation unit 36 generates a steering control command for moving the dump truck 200 along the second movement path, based on the position information of the dump truck 200, the second movement path of the dump truck 200, a current speed of the dump truck 200, and a control command relating to acceleration or deceleration of the dump truck 200 (S313).

[0100] Then, the communication control unit 37 transmits the steering control command and the control command relating to the speed to the wireless communication device 240 of the dump truck 200 via the wireless communication device 40 (S314).

[0101] The command generation unit 36 generates a steering control command of the asphalt finisher 100 to move the asphalt finisher 100 along the first movement path, based on the first movement path and the position information of the asphalt finisher 100. Then, the drive system controller 55 performs steering control in accordance with the control command (S315).

[0102] Next, the control command generated by the command generation unit 36 will be described. Fig. 4 is a top view of a construction site, illustrating the first movement path and the second movement path which are generated by the path generation unit 33 for constructing a curved part (left curved part) of a road. In an example illustrated in Fig. 4, the asphalt finisher 100 paves a region between a left side boundary line LP and a right side boundary line RP with an asphalt mixture. Therefore, the asphalt finisher 100 spreads the screed device 3 until the screed device 3 reaches each of the left side boundary line LP and the right side boundary line RP.

[0103] The path generation unit 33 generates a first movement path AFL so that the asphalt finisher 100 can lay the asphalt mixture in the region between the left side boundary line LP and the right side boundary line RP. That is, the first movement path AFL indicates a movement path for the asphalt finisher 100 to pave a construction target region with the asphalt mixture, in accordance with the construction plan drawing.

[0104] In the present embodiment, the path generation unit 33 generates a second movement path DTL with reference to the first movement path AFL of the asphalt finisher 100. The second movement path DTL is a movement path of the dump truck 200. The dump truck 200 moves along the second movement path DTL. In this manner, while the asphalt finisher 100 moves along the first movement path AFL, the overlapping state between the loading platform 201 of the dump truck 200 and the hopper 2 of the asphalt finisher 100 in the vertical direction is maintained. Therefore, the dump truck 200 can realize stable supply of the paving material from the dump truck 200 to the asphalt finisher 100. In this way, in the present embodiment, a part of the dump truck 200 and the asphalt finisher 100 overlap each other. Therefore, the distance between the dump truck 200 and the asphalt finisher 100 disappears.

[0105] The second movement path DTL is a movement path used for control after the loading platform 201 of the dump truck 200 is positioned at the designated position. In other words, the controller 30 controls the dump truck 200 to position the loading platform 201 of the dump truck 200 at the designated position, and thereafter, performs automatic control along the second movement path DTL.

[0106] Then, after the paving material is completely supplied from the dump truck 200 to the asphalt finisher 100, the controller 30 completes the control of the dump truck 200 moving along the second movement path DTL. Thereafter, the dump truck 200 travels in accordance with the control on the dump truck 200 side (for example, the operation control of the driver or the driving assistance control using the ADAS on the dump truck 200 side). In this way, the controller 30 of the present embodiment controls the dump truck 200 by using the second movement path DTL only while the loading platform 201 of the dump truck 200 is positioned at the designated position. In this manner, the controller 30 can control a plurality of the dump trucks 200 along the second movement path DTL.

[0107] The first movement path AFL and the second movement path DTL are indicated by using a reference coordinate system. For example, the reference coordinate system is the world geodetic system. The reference coordinate system is not limited to the world geodetic system, and may be any coordinate system as long as the coordinate system can express a correspondence relationship between the position information received by the asphalt finisher 100 and the position information included in the construction plan drawing.

[0108] A point AP1 indicates a position of a front end of the asphalt finisher 100 at a first time point at which the construction starts. A point AP2 indicates the position of the front end of the asphalt finisher 100 at a second time point after the asphalt finisher 100 moves forward along the first movement path AFL for a predetermined time from the first time point. A point AP3 indicates the position of the front end of the asphalt finisher 100 at a third time point after the asphalt finisher 100 moves forward along the first movement path AFL for a predetermined time from the second time point.

[0109] The command generation unit 36 generates a control command for operating the asphalt finisher 100 so that an actual position coordinate indicated by the position (for example, the point AP1, the point AP2, or the point AP3) of the front end of the asphalt finisher 100 coincides with one of the position coordinates forming the first movement path AFL.

[0110] Specifically, the command generation unit 36 calculates position information indicating the position of the front end of the asphalt finisher 100 (for example, the point AP1, the point AP2, or the point AP3), based on the position information from the GPS module 50. Then, when steering in the rightward direction or in the leftward direction is needed to move along the first movement path AFL in the calculated position information, the command generation unit 36 generates a control command for steering in the rightward direction or in the leftward direction. In addition, the command generation unit 36 calculates a steering angle for moving along the first movement path AFL in accordance with the current speed, the acceleration, or the deceleration of the asphalt finisher 100. The calculated steering angle is included in the control command.

[0111] A point DP1 indicates the position of the front end of the dump truck 200 at the first time point at which the construction starts. A point DP2 indicates the position of the front end of the dump truck 200 at the second time point after the dump truck 200 moves forward along the second movement path DTL for a predetermined time from the first time point. A point DP3 indicates the position of the front end of the dump truck 200 at the third time point after the dump truck 200 moves forward along the second movement path DTL for a predetermined time from the second time point.

[0112] The command generation unit 36 generates a control command for operating the dump truck 200 so that the actual position coordinate indicated by the position of the front end of the dump truck 200 (for example, the point DP1, the point DP2, or the point DP3) coincides with one of the position coordinates forming the second movement path DTL. Furthermore, the command generation unit 36 generates a control command for maintaining the state where the hopper 2 of the asphalt finisher 100 and the loading platform 201 of the dump truck 200 overlap each other in the vertical direction.

[0113] Specifically, the command generation unit 36 generates a control command relating to the speed of the dump truck 200, based on the speed, the acceleration, or the deceleration of the asphalt finisher 100. Furthermore, the command generation unit 36 calculates the position information indicating the position of the front end of the dump truck 200 (for example, the point DP1, the point DP2, or the point DP3), based on the position information from the GPS module 50. Then, when steering in the rightward direction or in the leftward direction is needed to move along the second movement path in the calculated position information, the command generation unit 36 generates a control command for steering in the rightward direction or in the leftward direction. In addition, the command generation unit 36 calculates a steering angle for moving along the second movement path, in accordance with the current speed of the dump truck 200 and the acceleration or the deceleration indicated by the control command relating to the speed. The calculated steering angle is included in the control command. Then, the communication control unit 37 transmits the control command for the dump truck 200 to the wireless communication device 240 of the dump truck 200 via the wireless communication device 40.

[0114] Referring back to Fig. 3, the controller 30 determines whether or not the paving material is completely supplied from the dump truck 200 (S316). A method for determining whether or not the paving material is completely supplied may be any method, and for example, may be a notification from the dump truck 200. When it is determined that the paving material is not completely supplied (S316: No), the controller 30 performs process subsequent to S310.

[0115] When the controller 30 determines that the paving material is completely supplied (S315: No), the communication control unit 37 transmits the control command generated by the command generation unit 36 to separate the dump truck 200 from the asphalt finisher 100, to the wireless communication device 240 of the dump truck 200 (S316).

[0116] Thereafter, the controller 30 determines whether or not the construction along the first movement path is completed (S317). When it is determined that the construction is not completed (S317: No), the controller 30 performs the processes subsequent to S305 again.

[0117] On the other hand, when it is determined that the construction is completed (S317: No), the controller 30 completes the process.

[0118] The asphalt finisher 100 of the present embodiment can pave the construction target region with the asphalt mixture by performing the above-described process.

[0119] The controller 30 of the above-described embodiment generates the second movement path of the transport vehicle such as the dump truck 200 so that the overlapping state can be maintained when the asphalt finisher 100 travels along the first movement path. In this manner, the controller 30 can synchronize the steering of the asphalt finisher 100 and the steering of the dump truck 200 with each other. The determination unit 35 of the controller 30 according to the present embodiment can determine whether or not the overlapping state between the hopper 2 and the loading platform 201 is maintained, based on the position relationship between the rear wheel of the dump truck 20 and the roller 2b of the asphalt finisher 100 (position relationship between components of respective vehicles). However, in the present embodiment, it is not always necessary to use the rear wheel of the dump truck 20 or the roller 2b of the asphalt finisher 100 in determining whether or not the overlapping state is maintained. For example, it may be determined whether or not the hopper 2 maintains the overlapping state with the loading platform 201, based on the position relationship between a front end of the hopper 2 and a rear end of the loading platform 201. In other words, the controller 30 according to the present embodiment may perform control to maintain the overlapping state, based on the position relationship between the front end of the hopper 2 and the rear end of the loading platform 201.

[0120] Next, generating the control command relating to the speed in the command generation unit 36 in S311 will be specifically described. In the present embodiment, the determination unit 35 identifies the inter-vehicle component distance between the rear wheel 202 of the dump truck 200 and the roller 2b of the asphalt finisher 100 from the image information acquired by the acquisition unit 32. Then, the command generation unit 36 of the present embodiment generates a control command for acceleration or deceleration of the dump truck 200 so that the inter-vehicle component distance falls within a range of a predetermined distance "A" from a distance "0". In this way, the speed of the dump truck 200 is controlled so that the distance between the component forming the dump truck 200 and the component constituting the asphalt finisher 100 falls within a predetermined range.

[0121] Figs. 5A to 5C are conceptual diagrams illustrating a position relationship between the rear wheel 202 of the dump truck 200 and the roller 2b of the asphalt finisher 100 according to the present embodiment. Fig. 5A is a view illustrating a case where the inter-vehicle component distance between the rear wheel 202 of the dump truck 200 and the roller 2b of the asphalt finisher 100 is a distance "0".

[0122]  Fig. 5B is a view illustrating a case where the inter-vehicle component distance between the rear wheel 202 of the dump truck 200 and the roller 2b of the asphalt finisher 100 is a predetermined distance "A". In an example illustrated in Fig. 5B, the rear end part of the loading platform 201 of the dump truck 200 and the tip part of the hopper 2 of the asphalt finisher 100 overlap each other in the vertical direction. In other words, when the inter-vehicle component distance between the rear wheel 202 of the dump truck 200 and the roller 2b of the asphalt finisher 100 exceeds the predetermined distance "A", the hopper 2 and the loading platform 201 of the dump truck 200 do not overlap each other in the vertical direction. In this case, when the loading platform 201 is dumped up, there is a possibility that the paving material may fall to a road surface without being supplied to the hopper 2 from the loading platform 201.

[0123] The command generation unit 36 of the controller 30 of the present embodiment generates the control command relating to the speed so that the inter-vehicle component distance between the rear wheel 202 (example of the component of the dump truck 200) of the dump truck 200 and the roller 2b (example of the component of the asphalt finisher 100) of the asphalt finisher 100 falls within a predetermined range ("0" ≤ inter-vehicle component distance ≤ "A"). In the present embodiment, the control is switched depending on whether or not the inter-vehicle component distance is shorter than a reference distance. The reference distance according to the present embodiment is defined as an intermediate distance "A/2" between the distance "0" which is the inter-vehicle component distance in Fig. 5A and the predetermined distance "A" which is the inter-vehicle component distance in Fig. 5B. In the present embodiment, an example in which the distance between the rear wheel 202 serving as the component of the dump truck 200 and the roller 20b serving as the component of the asphalt finisher 100 is used as a determination reference will be described. However, in the present embodiment, the components used for the distance determination reference are not limited to the rear wheel 202 and the roller 20b, and other components may be used.

[0124] Fig. 5C is a view illustrating a case where the inter-vehicle component distance between the rear wheel 202 of the dump truck 200 and the roller 2b of the asphalt finisher 100 is a reference distance "A/2". Then, the controller 30 switches the control (for example, acceleration or deceleration) relating to the speed of the dump truck 200 depending on whether or not the inter-vehicle component distance is shorter than the reference distance "A/2". The acceleration or the deceleration with respect to the dump truck 200 is set in advance. In addition, the acceleration or the deceleration with respect to the dump truck 200 may be changed depending on the inter-vehicle component distance. Next, a specific process of S311 in Fig. 3 in the controller 30 according to the present embodiment will be described.

[0125] Specifically, after the determination unit 35 recognizes the position information of the asphalt finisher 100 and the position information of the dump truck 200 in S310, the determination unit 35 determines whether or not the inter-vehicle component distance between the rear wheel 202 of the dump truck 200 and the roller 2b of the asphalt finisher 100 is shorter than the reference distance "A/2".

[0126] When the determination unit 35 determines that the inter-vehicle component distance is shorter than the reference distance "A/2", the command generation unit 36 generates a control command for accelerating the dump truck 200. For example, the acceleration indicated by the control command increases as the inter-vehicle component distance is shorter than the reference distance "A/2".

[0127]  On the other hand, when the determination unit 35 determines that the inter-vehicle component distance is not shorter than the reference distance "A/2", the command generation unit 36 determines whether or not the inter-vehicle component distance is longer than the reference distance "A/2". When the determination unit 35 determines that the inter-vehicle component distance is long, the command generation unit 36 generates a control command for decelerating the dump truck 200. For example, the deceleration indicated by the control command increases as the inter-vehicle component distance is longer than the reference distance "A/2".

[0128] On the other hand, when the determination unit 35 determines that the inter-vehicle component distance is not longer than the reference distance "A/2", in other words, the inter-vehicle component distance is equal to the reference distance "A/2", the command generation unit 36 generates a control command for causing the dump truck 200 to maintain the current speed. In this way, the controller 30 performs control for increasing or decreasing the speed of the dump truck 200 with respect to the asphalt finisher 100.

[0129]  The command generation unit 36 of the present embodiment generates the above-described control command for accelerating, the above-described control command for decelerating, or the above-described control command for maintaining the speed, as the control command relating to the speed. After the command generation unit 36 generates these control commands, processes subsequent to S312 are performed.

[0130] In this way, the controller 30 of the present embodiment generates the control command relating to the speed of the dump truck 200 in accordance with the position relationship between the dump truck 200 and the asphalt finisher 100. In this manner, the controller 30 can synchronize the speed of the asphalt finisher 100 and the speed of the dump truck 200 with each other.

(Second Embodiment)

[0131] As a method for generating the control command relating to the speed of the dump truck 200, the first embodiment adopts a method for switching control relating to the speed, depending on the inter-vehicle component distance between the rear wheel 202 of the dump truck 200 and the roller 2b of the asphalt finisher 100. However, the above-described embodiment is not limited to the method in which the controller 30 of the asphalt finisher 100 switches the generation of the control command relating to the speed of the dump truck 200, depending on the inter-vehicle component distance. Therefore, hereinafter, a second embodiment in which the control command relating to the speed is generated by using a method different from that of the first embodiment will be described. The asphalt finisher 100 and the dump truck 200 of the second embodiment have the same configurations as those of the first embodiment, and thus, description thereof will be omitted.

[0132] In S312, the controller 30 of the second embodiment calculates a difference between the speed of the control command transmitted in S309 and the actual speed of the dump truck 200, and controls the speed of the dump truck 200, based on the calculated difference. When the dump truck 200 travels at a speed indicated by the control command transmitted in S309, it is possible to maintain the state where the hopper 2 of the asphalt finisher 100 and the loading platform 201 of the dump truck 200 overlap each other in the vertical direction.

[0133] However, actually, a deviation occurs between the speed of the control command and the actual speed due to air resistance of the dump truck 200 or a loss caused by mechanical control. When the deviation occurs in this way, it becomes difficult to maintain the state where the hopper 2 of the asphalt finisher 100 and the loading platform 201 of the dump truck 200 overlap each other in the vertical direction. Therefore, in the second embodiment, the controller 30 performs feedback control of the speed of the dump truck 200.

[0134] Specifically, the acquisition unit 32 acquires information on the actual speed of the dump truck 200. For example, as an acquisition method, the acquisition unit 32 may acquire information on the actual speed received from the dump truck 200 via the communication control unit 37. As another example, the acquisition unit 32 may estimate the actual speed of the dump truck 200, based on the image of the dump truck 200 in the image information captured by the imaging device 62.

[0135] Then, the determination unit 35 calculates a difference between the speed indicated by the control command transmitted to the dump truck 200 in S309 and the actual speed of the dump truck 200.

[0136]  Then, the command generation unit 36 generates a control command for performing feedback control to travel at the speed indicated by the speed control command, based on the difference between the speed indicated by the control command and the actual speed of the dump truck 200. For example, as the feedback control method, a well-known method such as PID control may be used.

[0137] In the second embodiment, the command generation unit 36 generates the control command based on the above-described feedback control, as the control command relating to the speed. Then, after the command generation unit 36 generates the control command, the communication control unit 37 transmits the control command to the dump truck 200 via the wireless communication device 40. In this way, the controller 30 performs the processes subsequent to S312 in Fig. 3. That is, when receiving the control command, the controller 230 of the dump truck 200 performs the feedback control to reduce the difference between the speed indicated by the control command transmitted in S309 and the actual speed of the dump truck 200. In this manner, the controller 230 can bring the actual speed of the dump truck 200 close to the speed indicated by the speed control command.

[0138]  In addition, as in the first embodiment, the command generation unit 36 of the second embodiment may generate the control command for accelerating, decelerating, or maintaining the speed of the dump truck 200, based on the inter-vehicle component distance.

[0139] Furthermore, the command generation unit 36 of the second embodiment may generate the speed control command, depending on whether or not the inter-vehicle component distance between the roller 2b of the asphalt finisher and the rear wheel 202 of the dump truck 200 is shorter than the reference distance "A/2".

[0140] For example, when the determination unit 35 determines that the inter-vehicle component distance is shorter than the reference distance "A/2", the command generation unit 36 generates a control command for traveling at a speed higher than the current speed of the asphalt finisher. For example, as another example, when the determination unit 35 determines that the inter-vehicle component distance is longer than the reference distance "A/2", the command generation unit 36 generates a control command for traveling at a speed lower than the current speed of the asphalt finisher.

[0141]  Furthermore, when a disturbance (for example, an inclination of a road surface or an obstacle) exists in front of the dump truck 200, before the asphalt finisher 100 and the dump truck 200 receive an influence of the disturbance, the command generation unit 36 may generate a control command for suppressing the influence.

[0142] For example, the communication control unit 37 of the asphalt finisher 100 may receive the image information captured by the first imaging device 261 of the dump truck 200 via the wireless communication device 40, and the command generation unit 36 may correct the control command relating to the speed, based on a situation indicated by the image information. For example, when the determination unit 35 determines that the traveling direction of the dump truck 200 is an uphill slope, based on the image information, the command generation unit 36 performs feed-forward control for increasing an acceleration degree in advance with respect to the generated control command. The command generation unit 36 of the second embodiment may generate a control command based on the control in which the feed-forward control and the above-described feedback control are combined.

[0143]  In the second embodiment, the controller 30 performs the above-described control to synchronize the speed of the dump truck 200 and the speed of the asphalt finisher 100 with each other. In this manner, the controller 30 of the second embodiment maintains a constant inter-vehicle component distance between the dump truck 200 and the asphalt finisher 100, and maintains the state where the loading platform 201 of the dump truck 200 overlaps the hopper 2 of the asphalt finisher 100 in the vertical direction.

[0144] The controller 30 of the second embodiment generates a control command based on the feedback control relating to the speed of the dump truck 200 in accordance with a difference between the speed indicated by the control command of the dump truck 200 and the actual speed. In this manner, as in the first embodiment, the controller 30 can synchronize the speed of the asphalt finisher 100 and the speed of the dump truck 200 with each other.

[0145] The controller 30 of the above-described embodiment synchronizes the operation of the transport vehicle such as the dump truck 200 and the operation of the asphalt finisher 100 with each other by performing the above-described control. The operation to be synchronized is not limited to the steering and the speed, and may be turning on/off a headlight or a winker or outputting warning information.

[0146] In the above-described example, a case where the imaging device 62 images the space existing in front of the asphalt finisher 100 has been described. Then, when the dump truck 200 is detected in front of the asphalt finisher 100, the controller 30 controls the dump truck 200. However, the present embodiment is not limited to a case where the transport vehicle serving as a control target exists in front of the asphalt finisher 100. The controller 30 may control a transport vehicle existing around the asphalt finisher 100 as the control target. For example, when the asphalt finisher 100 further includes an imaging device capable of imaging in a rightward-leftward direction, the controller 30 may control the dump truck detected by the imaging device as the control target. In this case, for example, the controller 30 of the asphalt finisher 100 transmits a control command to the detected dump truck to move rearward after moving forward. The control subsequent thereto is the same as the control in the above-described embodiment. In this way, the detection device such as the imaging device may have a detection range as long as the range is located around the asphalt finisher 100. Then, the controller 30 may control the transport vehicle detected within the detection range.

[0147] In addition, in the above-described example, a case where the imaging device 62 detects the transport vehicle such as the dump truck 200 has been described. However, in the present embodiment, the detection device that detects the transport vehicle is not limited to the imaging device. The detection device may be a sensor capable of detecting the position of the dump truck 200. For example, the detection device may be a range sensor such as Light Detection and Ranging, Laser Imaging Detection and Ranging (LIDAR) or a millimeter-wave radar.

[0148] The steering information for steering the dump truck 200, which is transmitted to the dump truck 200 by the asphalt finisher 100, is not limited to the steering control command, and may be any information required for steering the dump truck 200. For example, when the dump truck 200 receives the second movement path and can be steered along the second movement path, the asphalt finisher 100 may transmit the second movement path, as the steering information.

[0149]  In the above-described embodiment, according to the above-described configuration, the asphalt finisher 100 synchronizes the operation of the asphalt finisher 100 and the operation of the dump truck 200 with each other. In this manner, it is possible to reduce a manual steering burden on the driver of the dump truck 200.

[0150] Furthermore, the asphalt finisher 100 synchronizes the steering of the asphalt finisher 100 and the steering of the dump truck 200 with each other. In this manner, a deviation in the position relationship between the loading platform 201 of the dump truck 200 and the hopper 2 of the asphalt finisher 100 can be prevented. Therefore, the paving material can be stably supplied from the dump truck 200 to the asphalt finisher 100. In this manner, the asphalt finisher 100 can prevent quality degradation of an asphalt pavement surface after the construction.

(Modification Example)

[0151] In the above-described embodiment, an example of generating the first movement path for the asphalt finisher 100 and the second movement path for the dump truck 200 in the asphalt finisher 100 has been described. However, the above-described embodiment is not limited to the case of generating the first movement path for the asphalt finisher 100 and the second movement path for the dump truck 200 in the asphalt finisher 100. Therefore, in a modification example, the movement path is generated by an externally provided information processing device. That is, in the present modification example, in a construction assistance system for an asphalt finisher including the asphalt finisher 100, the dump truck 200, and an information processing device, an example will be described in which the information processing device generates the first movement path for the asphalt finisher 100 and the second movement path for the dump truck 200 to synchronize the operation of the dump truck 200 and the operation of the asphalt finisher 100 with each other.

[0152] The externally provided information processing device generates a first movement path for the asphalt finisher 100 and a second movement path for the dump truck 200 after performing an input process of the construction plan drawing.

[0153] Then, the information processing device transmits the first movement path for the asphalt finisher 100 and the second movement path for the dump truck 200 to the wireless communication device 40 of the asphalt finisher 100. The process subsequent thereto is the same as that in the above-described embodiment, and thus, description thereof will be omitted. As in the present modification example, as long as a device is included in the construction assistance system for the asphalt finisher, the control for synchronizing the operation of the dump truck 200 and the operation of the asphalt finisher 100 with each other may be performed.

[0154] In the above-described embodiment and modification example, the transport vehicle and the asphalt finisher are automatically controlled to move along the construction target region in a road pavement site. Therefore, safety relating to the road pavement is improved. Furthermore, in the above-described embodiment and modification example, the operator of the asphalt finisher can confirm a surrounding situation, based on the image information captured in front of the transport vehicle. Therefore, safety of the operator and surrounding workers is improved.

[0155] Hitherto, the embodiment and the modification example of the asphalt finisher, the dump truck (example of the transport vehicle), and the construction assistance system for the asphalt finisher have been described. However, the present invention is not limited to the above-described embodiment and modification example. Various changes, corrections, substitutions, additions, deletions, and combinations can be made within the scope described in the appended claims. As a matter of course, all of these also belong to the technical scope of the present invention.

[0156] The present application claims priority based on Japanese Patent Application No. 2021-056023 filed on March 29, 2021, and the entire contents of this Japanese patent application are incorporated herein by reference.

Reference Signs List

[0157] 

100:

Asphalt finisher

30:

Controller

31:

Dump truck identification information storage unit

32:

Acquisition unit

33:

Path generation unit

34:

Detection unit

35:

Determination unit

36:

Command generation unit

37:

Communication control unit

62:

Imaging device

Claims

1. An asphalt finisher comprising:

a tractor;

a hopper installed on a front side of the tractor;

a conveyor that conveys a paving material inside the hopper to a rear side of the tractor;

a screw that lays and spreads the paving material conveyed by the conveyor and scattered on a road surface in a vehicle width direction; and

a screed device that lays and levels the paving material laid and spread by the screw on a rear side of the screw,

wherein an operation of a transport vehicle is synchronized to correspond to an operation of the asphalt finisher.

2. The asphalt finisher according to claim 1,
wherein a control command for the asphalt finisher is generated to synchronize the operation of the transport vehicle with the operation of the asphalt finisher.

3. The asphalt finisher according to claim 1,
wherein a distance between a component forming the transport vehicle and a component forming the asphalt finisher is acquired to generate a control command for instructing acceleration or deceleration of the transport vehicle, based on the acquired distance.

4. The asphalt finisher according to claim 3,
wherein based on the acquired distance, the control command is generated so that a loading platform of the transport vehicle and the hopper are within a range of maintaining an overlapping state in a vertical direction.

5. The asphalt finisher according to claim 1,
wherein based on a speed of the asphalt finisher, a speed control command indicating a speed of the transport vehicle is generated.

6. The asphalt finisher according to claim 5,

wherein after the speed control command is transmitted, an actual speed of the transport vehicle is acquired, and

based on a difference between the actual speed of the transport vehicle and the speed indicated by the speed control command, a control command for feedback control is generated so that the transport vehicle travels at the speed indicated by the speed control command.

7. A construction assistance system for an asphalt finisher which is used for an asphalt finisher including a tractor, a hopper installed on a front side of the tractor, a conveyor that conveys a paving material inside the hopper to a rear side of the tractor, a screw that lays and spreads the paving material conveyed by the conveyor and scattered on a road surface in a vehicle width direction, and a screed device that lays and levels the paving material laid and spread by the screw on a rear side of the screw, the system comprising:
a control device configured to synchronize an operation of a transport vehicle in front of the asphalt finisher to correspond to an operation of the asphalt finisher.

8. The construction assistance system for an asphalt finisher according to claim 7,
wherein the control device is configured to generate a control command for the asphalt finisher to synchronize the operation of the transport vehicle with the operation of the asphalt finisher.

9. The construction assistance system for an asphalt finisher according to claim 7,
wherein the control device is configured to acquire a distance between a component forming the transport vehicle and a component forming the asphalt finisher, and to generate a control command instructing acceleration or deceleration of the transport vehicle, based on the acquired distance.

10. The construction assistance system for an asphalt finisher according to claim 7,
wherein the control device is configured to generate a speed control command indicating a speed of the transport vehicle, based on a speed of the asphalt finisher.

Drawing