WORK ASSISTANCE SYSTEM

Abstract

 A work assistance system (1) assists work of a work machine (10) including a machine body (10a) and an attachment (15). The work assistance system (1) includes an attachment operation lever (35a) and a controller (50). The attachment (15) is operatively attached to the machine body (10a) and performs work. The attachment operation lever (35a) receives input of an operation for operating the attachment (15). The controller (50) determines an offset amount (O) in accordance with a lever operation amount input to the attachment operation lever (35a).

Description

Technical Field

[0001] The present invention relates to a work assistance system.

Background Art

[0002] Patent Literature 1 describes a control device of a work machine that switches a topography to be a target of work on the basis of an orientation of an attachment. The control device switches a topography to be a target of work between a target construction topography which is a finishing target and an offset topography separated from the target construction topography by a predetermined distance.

Citation List

Patent Literature

[0003] Patent Literature 1: WO 2016/129708 A

[0004] In the technique described in Patent Literature 1, depending on a relative orientation of the work machine with respect to a target construction surface, it may not be possible to accurately determine whether current work is finishing work only by the orientation of the attachment. As a result, there is a problem that work is performed beyond a final target construction topography which is the finishing target, and the construction topography collapses.

Summary of Invention

[0005] An object of the present invention is to provide a work assistance system capable of preventing work beyond a final target construction topography from being performed.

[0006] A work assistance system according to one aspect of the present invention assists work of a work machine including a machine body and an attachment. The work assistance system includes an operation lever and a controller. The attachment is operatively attached to the machine body and performs work. The operation lever receives input of an operation for operating the attachment. The controller determines an offset amount in accordance with at least a lever operation amount input to the operation lever. The offset amount is an amount of an offset from a target construction topography as a finishing target to a work target topography as a target of the work of the work machine.

Brief Description of Drawings

[0007] 

[FIG. 1] FIG. 1 is a diagram of a work machine or the like of a work assistance system as viewed from the side.

[FIG. 2] FIG. 2 is a block diagram of a work assistance system illustrated in FIG. 1.

[FIG. 3] FIG. 3 is a flowchart of an operation of determining an offset amount on the basis of a lever operation amount by a controller illustrated in FIG. 2.

[FIG. 4] FIG. 4 is a flowchart of an operation of determining an offset amount on the basis of the lever operation amount and an actual speed of an attachment by the controller illustrated in FIG. 2.

[FIG. 5] FIG. 5 is a flowchart of an operation of determining the offset amount on the basis of the lever operation amount and a distance from a target construction topography to a distal end attachment by the controller illustrated in FIG. 2.

[FIG. 6] FIG. 6 is a flowchart of an operation of determining the lever operation amount with a threshold value and determining the offset amount by the controller illustrated in FIG. 2.

[FIG. 7] FIG. 7 is a flowchart of an operation of determining the offset amount by time-integrating the lever operation amount by the controller illustrated in FIG. 2.

[FIG. 8] FIG. 8 is a flowchart of an operation of time-integrating the lever operation amount to determine the offset amount and resetting the offset amount by the controller illustrated in FIG. 2.

[FIG. 9] FIG. 9 is a diagram illustrating a relationship between the lever operation amount, the offset amount, and the like in the flowchart illustrated in FIG. 8.

[FIG. 10] FIG. 10 is a diagram illustrating a modification of the offset amount, the target construction topography, and the like of the work assistance system.

Description of Embodiments

[0008] Hereinafter, a work assistance system 1 will be described with reference to the drawings.

[0009] The work assistance system 1 is a system that sets a topography (work target topography T2) to be a target of the work by a work machine 10. The work assistance system 1 determines an offset amount O between a target construction topography T1 and the work target topography T2. The work assistance system 1 determines the offset amount O in accordance with a lever operation amount. As illustrated in FIG. 1, the work assistance system 1 includes the work machine 10, an orientation sensor 31, a distance detection device 34 (distance detector) (see FIG. 2), an input device 35 (see FIG. 2), a controller 50 (computer), and a teaching device 70 (see FIG. 2). Note that the work assistance system 1 is not required to include the entire work machine 10. In this case, the work assistance system 1 may include some devices (for example, an operation unit) mounted on the work machine 10. The work assistance system 1 may assist work of the work machine 10 by transmitting and receiving signals to and from the work machine 10.

[0010] The work machine 10 is a machine that performs work. The work machine 10 is, for example, a construction machine that performs construction work. For example, the work machine 10 is an excavator. The work machine 10 may be configured to be operable by automatic control. The automatic control may be semi-automatic operation (machine control to be described later). The work machine 10 may operate without using automatic control. The work machine 10 may be operated by a worker (operator) boarding the work machine 10 or may be remotely operated. Hereinafter, a case where the work machine 10 is an excavator will be mainly described.

[0011] The work machine 10 includes a machine body 10a, an attachment 15, a drive control unit 17 (see FIG. 2), an actuator 21, and the orientation sensor 31.

[0012] The machine body 10a is a main part of the work machine 10. The machine body 10a includes a lower body 11 and an upper slewing body 13. The lower body 11 can travel on a traveling surface (the ground or the like).

[0013] The lower body 11 may include crawlers or wheels. The upper slewing body 13 is slewably mounted on the lower body 11.

[0014] A cab 13a is a portion where the worker (operator) can operate the work machine 10. Note that, in a case where the work machine 10 operates in accordance with the operation of the worker, the work machine 10 may be operated by the worker in the cab 13a, or may be remotely operated from the outside of the work machine 10.

(Directions)

[0015] The direction in which the rotation axis of slewing of the upper slewing body 13 with respect to the lower body 11 extends is defined as an up-down direction Z. In the up-down direction Z, a direction from the lower body 11 towards the upper slewing body 13 is defined as an upward direction Z1, and a direction opposite to the upward direction Z1 is defined as a downward direction Z2. A direction orthogonal to each of the up-down direction Z and the direction in which the rotation axis of a boom 15b (described later) with respect to the upper slewing body 13 extends is defined as a front-rear direction X (front-rear direction of the upper slewing body 13). In the front-rear direction X, a direction in which the attachment 15 protrudes from the upper slewing body 13 is defined as a front direction X1, and a direction opposite to the front direction X1 is defined as a rear direction X2.

[0016] The attachment 15 is a part that performs work. The attachment 15 is attached to the machine body 10a. For example, the attachment 15 includes the boom 15b, an arm 15c, and a distal end attachment 15d. The boom 15b is mounted on the upper slewing body 13 so as to be able to be raised and lowered (rotatable in an up-down direction Z). The arm 15c is rotatably attached to the boom 15b (rotatably along a plane including the front-rear direction X and the up-down direction Z).

[0017] The distal end attachment 15d is provided at a distal end of the attachment 15. The distal end attachment 15d is rotatably attached to the arm 15c (rotatably along a direction including the front-rear direction X and the up-down direction Z). The distal end attachment 15d may be a bucket capable of performing work of scooping a work object, excavation, and the like. The distal end attachment 15d may be a device (such as a grapple or a nibbler) that sandwiches a work object, a device (such as a breaker) that crushes a work object, or a magnet that attracts a metal work object.

[0018] The work object is an object to be worked on by the work machine 10. The work object may be earth, stone, wood, metal, resin, waste, or a structure (block or the like).

[0019] The actuator 21 is a device that causes the work machine 10 to operate. The actuator 21 may include hydraulic actuators driven by hydraulic pressure or include electric actuators driven by electric power. The actuator 21 may include a motor or may include an extendable cylinder. The actuator 21 includes a cylinder that causes the attachment 15 to operate. The actuator 21 includes a slewing motor 21a, a boom cylinder 21b, an arm cylinder 21c, and a distal end attachment cylinder 21d. The slewing motor 21a slews the upper slewing body 13 with respect to the lower body 11. The boom cylinder 21b raises and lowers the boom 15b with respect to the upper slewing body 13. The boom cylinder 21b is, for example, a cylinder (hydraulic cylinder) that is driven (expanded and contracted) by hydraulic pressure, for example (the same applies to the arm cylinder 21c and the distal end attachment cylinder 21d). The arm cylinder 21c rotates the arm 15c with respect to the boom 15b. The distal end attachment cylinder 21d rotates the distal end attachment 15d with respect to the arm 15c.

[0020] The drive control unit 17 (see FIG. 2) (also referred to as a drive unit) controls the actuator 21. The drive control unit 17 may include a hydraulic circuit that controls the hydraulic actuator 21. The drive control unit 17 may include an electric circuit that controls the electric actuator 21.

[0021] The orientation sensor 31 (also referred to as an orientation sensor unit) detects the orientation of the work machine 10. The orientation sensor 31 detects the orientation of the attachment 15. The orientation sensor 31 may be mounted on the work machine 10 or may be disposed outside the work machine 10 (for example, at a work site). The orientation sensor 31 may include an imaging device described later. The position sensor 33, the input device 35 (see FIG. 2), the controller 50, and the teaching device 70 (see FIG. 2) may be mounted on the work machine 10 or may be disposed outside the work machine 10. The orientation sensor 31 includes a slewing sensor 31a, a boom sensor 31b, an arm sensor 31c, a distal end attachment sensor 31d, and a reference position sensor 31e.

[0022] The slewing sensor 31a detects an angle (slewing angle) of the upper slewing body 13 with respect to the lower body 11 (or the work site). The boom sensor 31b detects the orientation of the boom 15b. For example, the boom sensor 31b detects an angle (inclination or rotation angle) of the boom 15b with respect to the horizontal direction or the upper slewing body 13. The arm sensor 31c detects the orientation of the arm 15c. The arm sensor 31c detects the angle of the arm 15c with respect to the horizontal direction or the boom 15b. The distal end attachment sensor 31d detects the orientation of the distal end attachment 15d. For example, the distal end attachment sensor 31d detects an angle of the distal end attachment 15d with respect to the horizontal direction or the arm 15c. In FIG. 2, the "distal end attachment" is described as the "distal end ATT". The reference position sensor 31e detects a position and an orientation of a reference portion of the work machine 10 illustrated in FIG. 1 with respect to the work site. The reference portion of the work machine 10 may be, for example, a specific portion of the upper slewing body 13 or the lower body 11, may be, for example, an attachment portion (boom foot) of the boom 15b to the upper slewing body 13, or may be, for example, a slewing center of the upper slewing body 13 with respect to the lower body 11. The reference position sensor 31e may perform detection by a positioning system. The positioning system may be a satellite positioning system, such as, a global navigation satellite system (GNSS). The positioning system may use a total station. The reference position sensor 31e may include an antenna for using a satellite positioning system. Note that, in FIG. 1, a reference sign of the reference position sensor 31e is assigned to the position of the GNSS antenna when the reference position sensor 31e performs detection by a positioning system using GNSS.

[0023] The position sensor 33 detects position information of an object that exists around the work machine 10. For example, the position sensor 33 may detect position information of the ground, or may detect position information of an obstacle or the like. The position sensor 33 may include, for example, an imaging device (described later).

[0024] The distance detection device 34 (see FIG. 2) detects a distance from the target construction topography T1 to the distal end attachment 15d. The distance detection device 34 may detect a height from the target construction topography T1 to the distal end attachment 15d. The distance detection device 34 may detect the distance from the target construction topography T1 to the distal end from data of the target construction topography T1 and the position of the distal end of the distal end attachment 15d. In this case, the distance detection device 34 may include the orientation sensor 31. The distance detection device 34 may detect the distance to the distal end attachment 15d from the position of the distal end attachment 15d detected on the basis of information of an image detected by the imaging device and the data of the target construction topography T1.

[0025] The imaging device may detect two-dimensional information (for example, a position and a shape in an image) of an imaging object. The imaging device may include a camera (monocular camera) that detects two-dimensional information. The imaging device may acquire a distance image, or may detect three-dimensional information (for example, three-dimensional coordinates or a three-dimensional shape) of the imaging object on the basis of the distance image. The imaging device may include a device that detects three-dimensional information with laser light, and may include, for example, a light detection and ranging (LIDAR), or, for example, a time of flight (TOF) sensor. The imaging device may include a device (for example, a millimeter wave radar) that detects three-dimensional information by using radio waves. The imaging device may include a stereo camera. The imaging device may detect three-dimensional information about the imaging object on the basis of the distance image and the two-dimensional image. Only one imaging device may be disposed, or a plurality of imaging devices may be disposed.

[0026] The input device 35 (see FIG. 2) is a device for a worker to input information. The input device 35 gives an instruction to the controller 50 on the basis of an operation by the worker. In a case where the input device 35 is provided in the work machine 10, the input device 35 may be, for example, a display, an operation lever, or the like provided in the cab 13a. The input device 35 may be a mobile terminal (tablet, smartphone, or the like) or a personal computer. The input device 35 may be provided in a server or the like outside the work machine 10. The input device 35 communicates with the controller 50. The input device 35 includes an attachment operation lever 35a (operation lever) (see FIG. 2). The attachment operation lever 35a is operated to control the orientation of the attachment 15. The operation speed of the attachment 15 changes in accordance with the lever operation amount of the attachment operation lever 35a.

[0027] The controller 50 is a computer that performs input/output of signals, calculation (processing), storage of information, and the like. The function of the controller 50 is implemented by executing a program stored in a storage 51 (see FIG. 2) of the controller 50 in the arithmetic unit (not illustrated). The controller 50 and another device (for example, the input device 35) may be connected by wireless communication or wired communication. In a case where there is a plurality of components of the controller 50, the components of the controller 50 may be connected by wireless communication or wired communication. For example, the communication is performed by communicating means such as a mobile phone line, an optical line, a wireless local area network (LAN), or a wired LAN. For example, as illustrated in FIG. 2, the controller 50 receives detection results from the orientation sensor 31, the position sensor 33, the distance detection device 34 (see FIG. 2), and the like. For example, the information (for example, the lever operation amount of the attachment operation lever 35a (see FIG. 2)) input by the input device 35 is input to the controller 50. For example, the controller 50 performs semi-automatic operation of the work machine 10. For example, the controller 50 outputs a command (command signal) for causing the work machine 10 to operate to the drive control unit 17 (see FIG. 2). For example, the controller 50 outputs information to the teaching device 70 (see FIG. 2). The controller 50 may be mounted on the work machine 10 or may be disposed outside the work machine 10. The controller 50 may be dispersedly arranged in a plurality of portions (may constitute a distributed system).

[0028] As illustrated in FIG. 2, the controller 50 includes an arithmetic unit (not illustrated) and the storage 51. Focusing on the function of the controller 50, the controller 50 includes a lever operation detector 52, an offset amount determiner 53, an offset amount resetting unit 54, a work target setting unit 55, an attachment actual speed detector 56, and an operation control unit 59. The storage 51 stores information. The storage 51 stores a program. The storage 51 stores a target operation. The storage 51 stores, for example, the work target topography T2 (see FIG. 1). The storage 51 stores, for example, the target construction topography T1 (see FIG. 1) and the offset amount O (see FIG. 1). The offset amount O will be described later. The storage 51 stores a threshold value (described later) of the lever operation amount for determining the work.

[0029] The lever operation detector 52 detects an operation on the attachment operation lever 35a. The lever operation detector 52 detects that a lever operation is performed on the attachment operation lever 35a. The lever operation detector 52 detects the lever operation amount for the attachment operation lever 35a.

[0030] The offset amount determiner 53 determines the offset amount O (see FIG. 1). The offset amount determiner 53 determines the offset amount O on the basis of the operation on the attachment operation lever 35a. The determination of the offset amount O will be described in detail later.

[0031] The offset amount resetting unit 54 resets the offset amount O (see FIG. 1). The offset amount resetting unit 54 resets the offset amount O in accordance with a condition. The resetting of the offset amount O will be described in detail later.

[0032] The work target setting unit 55 sets the target operation of the work machine 10 (see FIG. 1). As an example, the work target setting unit 55 sets the target operation of the work machine 10 with a preset target construction topography T1 as a reference. The work target setting unit 55 sets the work target topography T2 (see FIG. 1) on the basis of the set offset amount O (see FIG. 1). In a case where the offset amount O is zero, the work target setting unit 55 sets the work target topography T2 to the target construction topography T1 (see FIG. 1).

[0033] The attachment actual speed detector 56 detects an actual speed of the attachment 15. The attachment actual speed detector 56 may determine the actual speed of the attachment 15 on the basis of information from the orientation sensor 31. In this case, the attachment actual speed detector 56 acquires information detected by the orientation sensor 31.

[0034] The operation control unit 59 controls the movement (operation) of the work machine 10 (see FIG. 1). The operation control unit 59 outputs a command to the drive control unit 17. The operation control unit 59 may output a command to the drive control unit 17 in accordance with an operation by the worker. The operation control unit 59 may semi-automatically control the work machine 10 such that the work machine 10 (see FIG. 1) moves in accordance with the target operation (for example, the work target topography T2 (see FIG. 1)). The operation of the work machine 10 will be described in detail later.

[0035] The teaching device 70 is a device that teaches information to a worker (for example, an operator). The teaching device 70 teaches the worker the target operation. For example, the teaching device 70 teaches the worker the work target topography T2 (see FIG. 1). The teaching device 70 is not particularly limited as long as it can present information to the operator, and may be, for example, a display device that displays a video or an image, or a speaker that outputs sound. The teaching device 70 may include one or more of these multiple devices.

(Operation)

[0036] The work assistance system 1 (mainly the controller 50) is configured to perform the following operations. The work assistance program causes the controller 50 to execute the following operations. The work assistance system 1 implements a method in which the following operations are performed. Note that each operation (function) of the work assistance system 1 may be a "step" in the work assistance program and the work assistance method.

(Operation: Operation of Work Machine 10)

[0037] The work machine 10 illustrated in FIG. 1 may be operated by the worker in the cab 13a, may be remotely operated by the worker from the outside (remote operation device) of the work machine 10, or may be automatically operated. The work machine 10 is a machine (for example, an ICT construction machine) using information and communication technology (ICT).

[0038] For example, the work machine 10 may be operated by the worker with a function of a machine guidance (MG) system. Specifically, a target operation (for example, an operation of excavating along the work target topography T2) is set in the controller 50. Then, guidance on a position where work needs to be performed is provided to the worker so that the work machine 10 can operate (work) in accordance with the target operation. This guidance is output to, for example, an output device provided in the cab 13a of the work machine 10 or an output device provided in the remote operation device. Then, the worker operates the work machine 10 in accordance with the guidance. As a result, the work machine 10 operates in accordance with the target operation (for example, an operation of excavating along the work target topography T2).

[0039] For example, the work machine 10 may operate by a machine control (MC) system. Specifically, a target operation (for example, an operation of excavating along the work target topography T2) is set in the controller 50. Then, the worker operates, for example only some elements of the attachment 15 (for example, only the boom 15b). At this time, the controller 50 (see FIG. 2) automatically controls elements not operated by the worker (for example, the arm 15c and the distal end attachment 15d) such that the work machine 10 works in accordance with the target operation (for example, an operation of excavating along the work target topography T2). At this time, the controller 50 controls the operation of the work machine 10 on the basis of a detection value of the orientation sensor 31. As a result, the work machine 10 operates in accordance with the target operation (for example, an operation of excavating along the work target topography T2).

(Operation: Determination of Offset Amount O)

[0040] The controller 50 illustrated in FIG. 1 (specifically, the offset amount determiner 53 (see FIG. 2)) determines the offset amount O. The offset amount O is a distance (separation distance) between the target construction topography T1 as a finishing target and the work target topography T2 as the target of the work of the work machine 10. The controller 50 may determine the offset amount O in accordance with the lever operation amount for the attachment operation lever 35a. Hereinafter, the lever operation amount for the attachment operation lever 35a is also simply referred to as "lever operation amount". The operation amount of the boom 15b by the attachment operation lever 35a is also simply referred to as an "operation amount of the boom 15b" or the like (the same applies to the arm 15c and the distal end attachment 15d). The controller 50 may determine the offset amount O on the basis of the lever operation amount of the entire attachment 15 (the operation amount of the boom 15b, the operation amount of the arm 15c, and the operation amount of the distal end attachment 15d). The controller 50 may determine the offset amount O on the basis of the operation amount of some of the elements of the attachment 15 (for example, the boom 15b). That is, a part of the operation of the attachment 15 by the attachment operation lever 35a (for example, the operation of the boom 15b) may be the operation for determining the offset amount O.

[0041] An outline of specific examples of a method of determining the offset amount O corresponding to the lever operation amount by the controller 50 is as follows (details of each specific example will be described later). The controller 50 may determine the offset amount O in accordance with the type of work to be determined in accordance with the lever operation amount. The controller 50 may determine the type of work on the basis of the threshold value of the lever operation amount. Specifically, the type of work is, for example, ground leveling work and excavation work. In general, the lever operation amount at the time of performing the ground leveling work is smaller than the lever operation amount at the time of performing the excavation work. For example, in a case of determining that the work is the ground leveling work, the controller 50 may determine the offset amount O to zero. For example, the work target topography T2 when the ground leveling work is performed may be the target construction topography T1. The controller 50 may determine the offset amount O to a value corresponding to the lever operation amount. The controller 50 may determine the offset amount O in accordance with another parameter in addition to the lever operation amount. The other parameter may be information of the attachment 15, and may be, for example, the actual speed of the attachment 15 or the orientation of the attachment 15. The actual speed of the attachment 15 may be the actual speed of any element of the attachment 15. The orientation of the attachment 15 may be the orientation of any element of the attachment 15. The orientation of the attachment 15 may be, for example, a distance from the target construction topography T1 to the distal end attachment 15d. The controller 50 may determine the offset amount O on the basis of the lever operation amount in a predetermined period. The controller 50 may determine the offset amount O on the basis of a value obtained by time-integrating the lever operation amount.

(Operation: Resetting of Offset Amount O)

[0042] The controller 50 illustrated in FIG. 1 (specifically, the offset amount resetting unit 54 (see FIG. 2)) resets the offset amount O. The resetting may be performed by setting the offset amount O to zero or setting the offset amount O to an initial value that is not zero. An outline of specific examples of resetting of the offset amount O by the controller 50 is as follows (details of each specific example will be described later). The controller 50 may reset the offset amount O at a timing when the work changes. The controller 50 may reset the offset amount O, for example, in a case where the attachment operation lever 35a returns to a default position (neutral position). The controller 50 may reset the offset amount O in accordance with the type of work. For example, the controller 50 may reset the offset amount O in a case where the type of work is the ground leveling work. The controller 50 may perform resetting on the basis of a manual operation to the input device 35.

(Operation: Specific Examples of Method of Determining Offset Amount O)

[0043] A specific example in which the controller 50 (see FIG. 2) determines the offset amount O (see FIG. 1) on the basis of the lever operation amount for the attachment operation lever 35a (see FIG. 2) will be described with reference to a flowchart.

[0044] As illustrated in FIG. 3, first, the controller 50 (see FIG. 2) determines whether an operation of the attachment operation lever 35a (see FIG. 2) has been detected (step S10). In a case of not detecting the operation of the attachment operation lever 35a (NO in step S10), the controller 50 repeats the processing of step S10 until detecting the operation of the attachment operation lever 35a. In a case of detecting the operation of the attachment operation lever 35a (YES in step S10), the controller 50 calculates the lever operation amount (step S20). Then, the controller 50 calculates the offset amount O (see FIG. 1) (step S30). Thereafter, the controller 50 determines the work target topography T2 on the basis of the offset amount O (step S40), and ends this processing. Note that, although the same applies to the subsequent flowcharts, the controller 50 may proceed the processing to the first step without ending the processing.

[0045] Here, the offset amount O (see FIG. 1) corresponds to the lever operation amount. For example, the offset amount O may increase as the lever operation amount increases. For example, the offset amount O may increase stepwise as the lever operation amount increases. For example, the offset amount O may increase continuously as the lever operation amount increases. For example, the offset amount O may be proportional to the lever operation amount. For example, the offset amount O may be a linear function of the lever operation amount. Specifically, the offset amount O may be a value obtained by multiplying the lever operation amount by a constant. Specifically, the value may be expressed by the offset amount O= constant a × lever operation amount β. In this case, the offset amount O may be a value obtained by adding or subtracting another constant independent of the lever operation amount to or from a value obtained by multiplying the lever operation amount by the constant. Specifically, the value may be expressed by the offset amount O= constant a × lever operation amount β + constant c. For example, the offset amount O may be a quadratic function of the lever operation amount. For example, the offset amount O may be set on the basis of a relationship (map) between the lever operation amount and the offset amount O.

[0046] Next, a specific example in which the controller 50 (see FIG. 2) determines the offset amount O (see FIG. 1) on the basis of the lever operation amount for the attachment operation lever 35a (see FIG. 2) and the actual speed of the attachment 15 (see FIG. 1) will be described with reference to a flowchart.

[0047] As illustrated in FIG. 4, first, the controller 50 (see FIG. 2) determines whether an operation of the attachment operation lever 35a (see FIG. 2) has been detected (step S110). In a case of not detecting the operation of the attachment operation lever 35a (NO in step S110), the controller 50 repeats the processing of step S110 until detecting the operation. In a case of detecting the operation of the attachment operation lever 35a (YES in step S110), the controller 50 calculates the lever operation amount (step S120). Then, the controller 50 calculates an attachment actual speed (step S130). Then, the controller 50 calculates the offset amount O on the basis of the lever operation amount and the attachment actual speed (step S140). Thereafter, the controller 50 determines the work target topography T2 on the basis of the offset amount O (step S150), and ends this processing.

[0048] Here, the offset amount O (see FIG. 1) corresponds to the actual speed of the attachment 15 (see FIG. 1). For example, the offset amount O may increase as the actual speed of the attachment 15 increases. The offset amount O may increase stepwise as the actual speed of the attachment 15 increases. The offset amount O may increase continuously as the actual speed of the attachment 15 increases. The offset amount O may be proportional to the actual speed of the attachment 15. For example, the offset amount O may be a sum of a value obtained by multiplying the lever operation amount by a constant and a value obtained by multiplying the actual speed of the attachment 15 by another constant. Specifically, the value may be represented by the offset amount O= constant a × lever operation amount β + constant b × actual speed ω of the attachment 15. For example, the offset amount O may be a quadratic function or the like. For example, the offset amount O may be set on the basis of a relationship (map) between the lever operation amount and the offset amount O for the actual speed of the attachment 15. The attachment 15 for measuring the actual speed may be the boom 15b, the arm 15c, or the distal end attachment 15d. For example, the actual speed of the attachment 15 may be a moving speed of the bucket.

[0049] Next, a specific example in which the controller 50 (see FIG. 2) determines the offset amount O (see FIG. 1) on the basis of the lever operation amount and the distance from the target construction topography T1 (see FIG. 1) to the distal end attachment 15d (see FIG. 1) will be described with reference to a flowchart.

[0050] As illustrated in FIG. 5, first, the controller 50 (see FIG. 2) determines whether an operation of the attachment operation lever 35a (see FIG. 2) has been detected (step S210). In a case of not detecting the operation of the attachment operation lever 35a (NO in step S210), the controller 50 repeats the processing of step S210 until detecting the operation. In a case of detecting the operation of the attachment operation lever 35a (YES in step S210), the controller 50 calculates the lever operation amount (step S220). Then, the controller 50 measures a distance from the target construction topography T1 (see FIG. 1) to the distal end attachment 15d (see FIG. 1) (step S230). Then, the controller 50 calculates the offset amount O (see FIG. 1) on the basis of the lever operation amount and the distance from the target construction topography T1 to the distal end attachment 15d (step S240). Thereafter, the controller 50 determines the work target topography T2 on the basis of the offset amount O (step S250), and ends this processing.

[0051] Here, a timing of measuring the distance from the target construction topography T1 (see FIG. 1) to the distal end attachment 15d (see FIG. 1) may be a timing when the operation of the attachment operation lever 35a is started. The timing of measuring the distance from the target construction topography T1 to the distal end attachment 15d may be a timing immediately before the operation of the attachment operation lever 35a is started. The timing of measuring the distance from the target construction topography T1 to the distal end attachment 15d may be a timing immediately before the attachment 15 moves. The timing of measuring the distance from the target construction topography T1 to the distal end attachment 15d may be a timing in a moment when the attachment 15 moves.

[0052] The offset amount O (see FIG. 1) corresponds to the distance from the target construction topography T1 (see FIG. 1) to the distal end attachment 15d (see FIG. 1). For example, the offset amount O may increase as a distance L (see FIG. 1) from the target construction topography T1 to the distal end attachment 15d increases. The distance L may be the shortest distance from the target construction topography T1 to the distal end attachment 15d, or may be the height from the target construction topography T1 to the distal end attachment 15d. The offset amount O may increase stepwise as the distance L increases. The offset amount O may increase continuously as the distance L increases. The offset amount O may be proportional to the distance L. For example, the offset amount O may be a sum of a value obtained by multiplying the lever operation amount by a constant and a value obtained by multiplying the distance from the target construction topography T1 to the distal end attachment 15d by another constant. Specifically, the value may be expressed by the offset amount O= constant a × lever operation amount β + constant c × distance L. For example, the offset amount O may be a quadratic function or the like. For example, the offset amount O may be set on the basis of a relationship (map) between the lever operation amount and the offset amount O for the distance from the target construction topography T1 to the distal end attachment 15d.

[0053] Next, a specific example in which the controller 50 (see FIG. 2) determines the offset amount O (see FIG. 1) in accordance with the work (for example, the type of work) determined from the lever operation amount of the attachment operation lever 35a (see FIG. 2) will be described with reference to a flowchart.

[0054] As illustrated in FIG. 6, first, the controller 50 (see FIG. 2) determines whether an operation of the attachment operation lever 35a (see FIG. 2) has been detected (step S310). In a case of not detecting the operation of the attachment operation lever 35a (NO in step S310), the controller 50 repeats the processing of step S310 until detecting the operation. In a case of detecting the operation of the attachment operation lever 35a (YES in step S310), the controller 50 calculates the lever operation amount (step S320). Then, the controller 50 determines whether the calculated lever operation amount is a threshold value or less (step S330). In a case of determining that the calculated lever operation amount is not the threshold value or less (NO in step S330), the controller 50 determines that the work performed by the work machine 10 (see FIG. 1) is the excavation work (step S340). Then, the controller 50 determines the offset amount O to a predetermined value (predetermined offset amount, fixed value) set in advance (step S350). On the other hand, in a case of determining that the calculated lever operation amount is the threshold value or less (YES in step S330), the controller 50 determines that the work performed by the work machine 10 is the ground leveling work (step S360). Then, the controller 50 determines the offset amount O to a value smaller than the predetermined offset amount set in advance (step S370). Then, the controller 50 determines the work target topography T2 on the basis of the offset amount O determined in step S350 or step S370 (step S380), and ends this processing.

[0055] In this manner, the controller 50 (see FIG. 2) determines the work (for example, the type of work) depending on whether the lever operation amount is the threshold value or more, and switches the offset amount O in accordance with the determined work. In a case where the lever operation amount is larger than the threshold value, the controller 50 sets the offset amount O to the predetermined offset amount. In a case where the lever operation amount is the threshold value or less, the controller 50 sets the offset amount O to be smaller than the predetermined offset amount. Here, the predetermined offset amount may be a constant value. The predetermined offset amount may be a different value depending on the lever operation amount. The offset amount O smaller than the predetermined offset amount may be 0 or a value larger than zero. The work target topography T2 (see FIG. 1) determined by the offset amount O smaller than the predetermined offset amount may be the same topography as the target construction topography T1 (see FIG. 1).

[0056] Next, a specific example in which the controller 50 (see FIG. 2) determines the offset amount O on the basis of a value obtained by integrating (for example, time-integrating) the lever operation amount will be described with reference to a flowchart.

[0057] As illustrated in FIG. 7, first, the controller 50 (see FIG. 2) determines whether an operation of the attachment operation lever 35a (see FIG. 2) has been detected (step S410). In a case of not detecting the operation of the attachment operation lever 35a (NO in step S410), the controller 50 repeats the processing of step S410 until detecting the operation. In a case of detecting the operation of the attachment operation lever 35a (YES in step S410), the controller 50 calculates the lever operation amount (step S420). Then, the controller 50 determines the work (for example, the type of work) performed by the work machine 10 in accordance with the operation of the attachment operation lever 35a. Specifically, the controller 50 determines whether the work performed by the work machine 10 is the ground leveling work (step S430). In a case where the work performed by the work machine 10 is not the ground leveling work (NO in step S430), the controller 50 proceeds with the processing to step S410. In a case where the work performed by the work machine 10 is the ground leveling work (YES in step S430), the controller 50 proceeds with the processing to step S410. Specifically, the controller 50 determines whether the operation amount of the arm 15c (see FIG. 1) by the attachment operation lever 35a is the threshold value or more and the distance L (see FIG. 1) is the threshold value or less (step S430). As described above, the distance L is a distance from the target construction topography T1 (see FIG. 1) to the distal end attachment 15d (see FIG. 1). The reason why the determination as to whether the work is the ground leveling work is performed on the basis of the operation amount of the arm 15c and the distance L will be described later. Note that, in FIG. 8 described later, the operation amount of the arm 15c is described as "arm lever operation amount". In a case where the operation amount of the arm 15c is not the threshold value or more or the distance from the target construction topography T1 to the distal end attachment 15d is not the threshold value or less (NO in step S430), the controller 50 proceeds with the processing to step S410. In a case where the operation amount of the arm 15c is the threshold value or more and the distance L from the target construction topography T1 to the distal end attachment 15d is the threshold value or less (YES in step S430), the controller 50 integrates (for example, time-integrates) the operation amount of the boom 15b (step S440). Note that, in FIG. 8 described later, the operation amount of the boom 15b is described as "boom lever operation amount". The controller 50 then calculates the offset amount O (see FIG. 1) on the basis of a value obtained by time-integrating the operation amount of the boom 15b (step S450). The controller 50 determines the work target topography T2 on the basis of the offset amount O (step S460), and ends this processing.

[0058] In the example illustrated in FIG. 7, in a case of determining that the work performed by the work machine 10 is the ground leveling work, the controller 50 determines the offset amount O on the basis of a value obtained by integrating the lever operation amount. The controller 50 may determine the offset amount O on the basis of a value obtained by integrating the lever operation amount without determining the work performed by the work machine 10.

[0059] Here, the offset amount O (see FIG. 1) may increase every time the attachment operation lever 35a (see FIG. 2) is operated. The offset amount O is not required to return to zero even when the lever operation amount becomes zero. The offset amount O may be determined on the basis of a value obtained by integrating the lever operation amount. The offset amount O may be determined on the basis of a value obtained by time-integrating the lever operation amount. A target period of time integration may be any period. For example, the target period of time integration may be a predetermined period from a current time to a predetermined time before. For example, the target period of time integration may be all periods of one cycle of work.

[0060] The reason why the controller 50 determines the offset amount O on the basis of a value obtained by integrating (for example, time integrating) the lever operation amount is as follows. For example, a case is considered where the offset amount O becomes a larger value as the lever operation amount increases, and the offset amount O becomes a smaller value as the lever operation amount decreases (for example, a case where the offset amount O = constant a × lever operation amount β). In this case, a case is considered where the lever operation amount of the attachment operation lever 35a rapidly decreases (for example, disappears) from a state where the lever operation amount is constant. In this case, since the lever operation amount suddenly decreases, the offset amount O suddenly decreases. Then, the work target topography T2 (see FIG. 1) before the offset amount O suddenly decreases and the work target topography T2 after the offset amount O suddenly decreases greatly deviate from each other. Then, an operation signal (signal input to drive control unit 17 (see FIG. 2) and signal for moving attachment 15) for the work machine 10 to work according to the work target topography T2 may change suddenly before and after the sudden decrease in the offset amount O. In this case, the movement of the work machine 10 suddenly changes. On the other hand, in a case where the controller 50 determines the offset amount O on the basis of a value obtained by integrating (for example, time-integrating) the lever operation amount, even when the lever operation amount suddenly decreases, the offset amount O (see FIG. 1) does not rapidly decrease in accordance with the lever operation amount. For example, even when the lever operation amount suddenly decreases, the offset amount O does not rapidly become zero (see FIG. 9). For example, the offset amount O may gradually decrease depending on the target period of time integration.

[0061] For example, a case is considered where the attachment operation lever 35a is suddenly operated from a state where the attachment operation lever 35a (see FIG. 2) is not operated, and the lever operation amount rapidly rises. In this case, similarly to the case where the lever operation amount suddenly decreases, the work target topography T2 before the offset amount O suddenly increases and the work target topography T2 after the offset amount O suddenly increases greatly deviate from each other. Then, there is a case where the movement of the work machine 10 suddenly changes. On the other hand, the controller 50 may determine the offset amount O on the basis of a value obtained by integrating (for example, time-integrating) the lever operation amount so that the offset amount O gradually increases without rapidly increasing in accordance with the lever operation amount. For example, the target period of time integration may be set such that the offset amount O gradually increases. In this manner, by determining the offset amount O on the basis of a value obtained by integrating (for example, time-integrating) the lever operation amount, even when the attachment operation lever 35a is suddenly operated, a sudden change in the offset amount O can be suppressed.

(Operation: Specific Examples of Resetting of Offset Amount O)

[0062] For example, the determination of the offset amount O (see FIG. 1) performed by the controller 50 may include resetting of the offset amount O. The resetting of the offset amount O may be performed as determination of the offset amount O. Specifically, in the example of FIG. 3, the offset amount O may be reset (set to zero or a default value) when the lever operation amount disappears. Specifically, in the example of FIG. 4, the offset amount O may be reset (to zero or a default value) when the lever operation amount and/or the attachment actual speed disappear. Specifically, in the example of FIG. 5, when the lever operation amount and/or the distance from the target construction topography T1 to the distal end attachment 15d disappears, the offset amount O may be reset (to zero or a default value). Specifically, in the example of FIG. 6, in a case where the lever operation amount is a threshold value or less (the ground leveling work), the offset amount O may be reset (to zero or a default value). Specifically, in the example of FIG. 7, the offset amount O may be reset (to zero or a larger default value) on the basis of a comparison between a value obtained by integrating (for example, time-integrating) the lever operation amounts and a threshold value. For example, the offset amount O may be reset in a case where a value obtained by integrating the lever operation amounts exceeds the threshold value. For example, depending on the setting of the target period of time integration, the value obtained by integrating the lever operation amount may decrease, but the offset amount O may be reset in a case where the value obtained by integrating the lever operation amounts is the threshold value or less.

[0063] For example, the resetting of the offset amount O may be performed as processing different from the determination of the offset amount O. A specific example in which the controller 50 resets the offset amount O as processing different from the determination of the offset amount O will be described with reference to a flowchart illustrated in FIG. 8. FIG. 9 illustrates a relationship between the lever operation amount, the offset amount O, and the like in the flowchart of FIG. 8.

[0064] Steps S510 to S560 illustrated in FIG. 8 are similar to steps S410 to S460 described with reference to FIG. 7, and thus description thereof is omitted. In a case where the offset amount O is calculated from the integrated value of the lever operation amounts, there is a possibility that the offset amount O remains without being reset. Therefore, the controller 50 (see FIG. 2) may perform the following reset processing. In the example of FIG. 8, the controller 50 resets the offset amount O on condition that the work machine 10 has performed a predetermined work. Specifically, the controller 50 resets the offset amount O on condition that the work machine 10 has completed the ground leveling work of one cycle.

[0065] As illustrated in FIG. 8, after step S560, the controller 50 (see FIG. 2) determines whether the ground leveling work of one cycle by the work machine 10 has been completed. Specifically, the controller 50 determines whether the operation amount of the arm 15c (see FIG. 1) is the threshold value or less or whether the distance L (see FIG. 1) from the target construction topography T1 (see FIG. 1) to the distal end attachment 15d (see FIG. 1) is the threshold value or more (step S570) (the reason for such determination will be described later). In a case where the operation amount of the arm 15c is not the threshold value or less and the distance from the target construction topography T1 to the distal end attachment 15d is not the threshold value or more (NO in step S570), the controller 50 proceeds with the processing to step S540. In a case where the operation amount of the arm 15c is the threshold value or less or the distance from the target construction topography T1 to the distal end attachment 15d is the threshold value or more (YES in step S570), the controller 50 resets the offset amount O and determines the work target topography T2 (see FIG. 1) (step S580).

[0066] In the example of FIG. 8, the controller 50 (see FIG. 2) resets the offset amount O (see FIG. 1) on condition that the work machine 10 (see FIG. 1) has completed the ground leveling work of one cycle, but the present disclosure is not limited to this example. In the examples of step S430 in FIG. 7 and step S530 in FIG. 8, it is determined whether the work performed by the work machine 10 is the ground leveling work. In this determination, a condition that the operation amount of the arm 15c (see FIG. 1) is a threshold value or more and the distance L (see FIG. 1) from the target construction topography T1 to the distal end attachment 15d (see FIG. 1) is the threshold value or less is set as a determination condition that the work is the ground leveling work. The reason for the above is as follows. In general, in the ground leveling work in a case where the work machine 10 is operated by machine control, the worker manually operates the arm 15c, and the boom 15b (see FIG. 1) and the distal end attachment 15d (for example, the bucket) (see FIG. 1) are automatically operated. In a case where the work of the work machine 10 proceeds from the excavation work to the ground leveling work, it is assumed that the distal end attachment 15d exists at a position close to the target construction topography T1. For example, in the ground leveling work, it is assumed that the distal end attachment 15d is moved along the target construction topography T1 at a position close to the target construction topography T1. Therefore, in the example of FIG. 8, as the determination condition that the work is the ground leveling work, "the manual operation of the attachment 15 (for example, the arm 15c) (see FIG. 1) is a threshold value or more when the distal end attachment 15d is located near the target construction topography T1" is set.

[0067] On the other hand, when the ground leveling work of one cycle is completed, normally, it is assumed that the arm 15c is not operated, the boom 15b is raised, and the distal end attachment 15d is separated from the target construction topography T1. Therefore, in step S570 in FIG. 8, a condition that the operation amount of the arm 15c is the threshold value or less or the distance L is the threshold value or more is set as the determination condition that the ground leveling work of one cycle has been completed. The determination condition that the work is the ground leveling work and the determination condition that the ground leveling work of one cycle has been completed can be variously set. For example, the controller 50 may determine the ground leveling work by using pressure information of the actuator 21 (see FIG. 1) or the orientation information of the attachment 15, or may determine the ground leveling work from a combination including the above information.

[0068] Another system to be compared with the work assistance system 1 according to the present embodiment will be examined. For example, it is assumed that a raised soil wall exists in front of the work machine 10, and a target construction topography is set in the soil wall. At this time, the attachment 15 performs work on the soil wall in an orientation extending forward and upward from the upper slewing body 13. In a case where the attachment 15 is in an orientation standing upward in this manner, the other system determines that the work to be performed is the excavation work. In this case, the work target topography is set with a predetermined offset amount for the target construction topography.

[0069] Eventually, when the excavation of the soil wall ends, the attachment 15 is brought into a lower orientation than at the time of the excavation work, and the ground leveling work of the soil wall is performed. In this case, the target construction topography is set as the work target topography. At this time, when the attachment 15 takes a relatively low orientation, the other system determines that the work to be performed is the ground leveling work.

[0070] On the other hand, in the other system as described above, it is assumed that there is a downhill inclined surface at a position lower than the ground in front of the work machine 10, and excavation and ground leveling work are performed on this inclined surface. In this case, the attachment 15 is set in a low orientation along the inclined surface. As a result, the other system determines that the work to be performed is the ground leveling work although the work is actually the excavation work. As a result, the excavation work is performed at a position close to the target construction topography, and the target construction topography collapses.

[0071] An effect of the work assistance system 1 according to the present embodiment illustrated in FIG. 2 is as follows. The work assistance system 1 assists work of the work machine 10 (see FIG. 1) having the machine body 10a and the attachment 15 (see FIG. 1). The work assistance system 1 includes the attachment operation lever 35a and the controller 50. The attachment 15 is operatively attached to the machine body 10a and performs work. The attachment operation lever 35a receives input of an operation for operating the attachment 15.

[0072] [Configuration 1] The controller 50 determines the offset amount O in accordance with at least the lever operation amount input to the attachment operation lever 35a. The offset amount O is an amount (distance or angle) of an offset from the target construction topography T1 as a finishing target to the work target topography T2 as the target of the work of the work machine 10. The work target topography T2 is a target topography (work surface) set on a front (work machine 10) side of the final target construction topography T1.

[0073] In [Configuration 1], the offset amount O from the target construction topography T1 is determined in accordance with the lever operation amount to the attachment operation lever 35a at least when the work targeting the target construction topography T1 is performed. The work target topography T2 based on the offset amount O can be set as the target of the work. Therefore, it is possible to prevent work beyond the final target construction topography T1 from being performed.

[0074] [Configuration 2] As illustrated in FIG. 2, the work assistance system 1 further includes the attachment actual speed detector 56. The attachment actual speed detector 56 detects an actual speed of the attachment 15. The controller 50 determines the offset amount O on the basis of the lever operation amount and the actual speed.

[0075] In [Configuration 2], the offset amount O is determined on the basis of the lever operation amount and the actual speed of the attachment 15. Not only in a case where the position of the attachment 15 is changed by the lever operation, but also in a case where the position of the attachment 15 is changed due to other external factors, the offset amount O is determined on the basis of an operation speed of the attachment 15. Therefore, it is possible to prevent work beyond the final target construction topography T1 from being performed due to other external factors. For example, depending on wind, topography, inclination, and the like at the work site, there is a possibility that the attachment 15 moves beyond a position and a motion amount corresponding to the lever operation amount. Even in such a case, since the offset amount O is set in consideration of the actual speed of the attachment 15, in a case where the attachment 15 approaches the target construction topography T1 at the actual speed exceeding the speed corresponding to the lever operation amount, the offset amount O is adjusted to be large, so that the work beyond the target construction topography T1 is prevented from being performed. An attachment speed is higher in the excavation work than in the finishing work. In a case where the attachment speed is high, in a case where a buried object is caught during excavation, or in a case where cavitation occurs, an actuator speed not associated with a lever input amount is generated, and a target construction surface (final target construction topography T1) may be damaged. Therefore, in a case where the actual speed is high, the target construction topography is offset by the offset amount O, so that the excavation work can be performed without exceeding the final target construction topography T1.

[0076] [Configuration 3] As illustrated in FIG. 1, the attachment 15 includes the distal end attachment 15d. As illustrated in FIG. 2, the work assistance system 1 further includes the distance detection device 34 that detects a distance (or a characteristic value corresponding to the distance) from the target construction topography T1 to the distal end attachment 15d. As illustrated in FIG. 5, the controller 50 determines the offset amount O on the basis of the lever operation amount and the distance L from the target construction topography T1 to the distal end attachment 15d.

[0077] In [Configuration 3], the offset amount O is determined on the basis of the lever operation amount and the distance from the target construction topography T1 to the distal end attachment 15d. Therefore, the offset amount O suitable for the distance L can be determined. For example, in a case where the work is divided into different works in accordance with the distance from the target construction topography T1 to the distal end attachment 15d, the offset amount O suitable for each of the different works can be determined. In a case where the lever operation amount is large or in a case where the distance from the target construction topography to the distal end attachment is long, the work currently performed is not finishing work but excavation work in many cases. At the time of excavation work, as described above, since there is a possibility of exceeding a final construction surface, a target construction topography offset from the final target construction topography T1 is set, and in a case of finishing work, a position closer to the final target construction topography is set as the target construction topography.

[0078] [Configuration 4] As illustrated in FIG. 6, the controller 50 (see FIG. 2) determines the offset amount O (see FIG. 1) to be a predetermined fixed value in a case where the lever operation amount is a predetermined threshold value or more. Note that, as an example, the threshold value is set corresponding to the operation amount by which the operator operates the attachment operation lever 35a when performing the excavation work (excavation work threshold value).

[0079] In [Configuration 4], the offset amount O is determined to be a predetermined fixed value in a case where the lever operation amount is the threshold value or more. As a result, the offset amount O can be set to a stable value. For example, by offsetting the target construction surface with the stable offset amount O at the time of the excavation work, it is possible to prevent the target construction surface from being changed during the excavation work and disturbing the excavation operation.

[0080] [Configuration 5] As illustrated in FIG. 6, the controller 50 (see FIG. 2) determines the offset amount O (see FIG. 1) to be zero in a case where the lever operation amount is less than a predetermined threshold value. Note that, as an example, the threshold value is set corresponding to the operation amount by which the operator operates the attachment operation lever 35a when performing the ground leveling work (ground leveling work threshold value).

[0081] In [Configuration 5], in a case where the lever operation amount is less than the threshold value, the offset amount O (see FIG. 1) is determined to be zero, and the target construction topography T1 (see FIG. 1) serves as the target of the work. In general, in a case where the lever operation amount is small, it is assumed that the work performed by the work machine 10 is the ground leveling work at a position close to the target construction topography T1. As a result, it is possible to prevent the offset amount O from being set in work at a position close to the target construction topography T1. Specifically, since construction accuracy is required at the time of the ground leveling work, it is necessary to perform construction in accordance with the final target topography. Therefore, when the offset amount O is set, it is not possible to excavate the final target topography, and the offset amount is set to zero in order to prevent deterioration of the construction accuracy.

[0082] [Configuration 6] The lever operation amount changes in accordance with the change in the position (inclination) of the attachment operation lever 35a, and the controller 50 (see FIG. 2) resets the offset amount O (see FIG. 1) in a case where the attachment operation lever 35a (see FIG. 2) returns to the default position.

[0083] In [Configuration 6], in a case where the attachment operation lever 35a (see FIG. 2) returns to the default position, the offset amount O (see FIG. 1) is reset. In a case where the attachment operation lever 35a returns to the default position, there is a possibility that the work to be performed next is different from the previous work. Therefore, by resetting the offset amount O at the timing when the attachment operation lever 35a returns to the default position, it is possible to suppress the application of the offset amount O of the previous work in the next work.

[0084] [Configuration 7] As illustrated in FIG. 7, the controller 50 (see FIG. 2) determines the offset amount O (see FIG. 1) on the basis of a value (integrated value) obtained by integrating the lever operation amounts.

[0085] In [Configuration 7], the offset amount O (see FIG. 1) is determined on the basis of (in accordance with) a value obtained by integrating the lever operation amounts. As a result, even in a case where the lever operation is suddenly stopped, the value obtained by time-integrating the lever operation amount does not suddenly decrease. Therefore, the offset amount O is prevented from being suddenly changed. Therefore, in a case where the offset amount O is applied to machine control, it is possible to prevent the work machine 10 from performing an unexpected operation due to a sudden change in the offset amount O.

[0086] [Configuration 8] As illustrated in FIG. 6, the controller 50 (see FIG. 2) can determine whether the work is the ground leveling work on the target construction topography T1 (see FIG. 1). In a case where it is determined that the ground leveling work of one cycle set in advance has ended, the controller 50 resets the offset amount O.

[0087] In [Configuration 8], in a case where the work is switched to the ground leveling work of the target construction topography T1 (see FIG. 1), the offset amount O (see FIG. 1) can be reset.

(Modifications)

[0088] The above embodiment may be modified in various ways. For example, various examples (including modifications) of the above embodiment may be variously combined. For example, the connection of the components illustrated in FIG. 2 and the like may be changed. For example, the number of the components (including modifications) in the above embodiment may be changed, and some of the components do not have to be provided. For example, the arrangement of the components may be changed.

[0089] For example, an inclusion relationship of the components may be variously changed. For example, a component described as a lower component included in a certain higher component is not required to be included in the higher component, and may be included in another component. For example, a plurality of members and parts described as those different from each other may be as one member or one part. For example, what has been described as one member or part may be divided and provided as a plurality of members or parts different from each other. For example, the order of steps in the flowchart illustrated in FIGS. 3 to 8 may be changed, and some of the steps are not required to be performed. For example, each component may have only some of each feature (function, arrangement, shape, operation, and the like).

[0090] For example, as illustrated in FIG. 10, the offset amount O may be an angle formed with the target construction topography T1. The controller 50 (specifically, the offset amount determiner 53 (see FIG. 2)) may set, as the work target topography T2, a topography rotated by the offset amount O from the target construction topography T1.

[0091] A work assistance system according to a first aspect of the present invention is configured to assist work of a work machine including a machine body, and an attachment that is operatively attached to the machine body and performs work, the work assistance system including an operation lever that receives input of an operation for operating the attachment; and a controller, in which the controller determines an offset amount from a target construction topography as a finishing target to a work target topography as a target of the work of the work machine in accordance with at least a lever operation amount input to the operation lever.

[0092] A work assistance system according to a second aspect of the present invention further includes, in the work assistance system according to the first aspect, an attachment actual speed detector that detects an actual speed of the attachment, in which the controller determines the offset amount on a basis of the lever operation amount and the actual speed.

[0093] In a work assistance system according to a third aspect of the present invention, in the work assistance system according to the first or second aspect, the attachment includes a distal end attachment, the work assistance system further includes a distance detector that detects a distance from the target construction topography to the distal end attachment, and the controller determines the offset amount on a basis of the lever operation amount and the distance.

[0094] In a work assistance system according to a fourth aspect of the present invention, in the work assistance system according to the first to third aspects, the controller determines the offset amount to a predetermined fixed value in a case where the lever operation amount is a predetermined threshold value or more.

[0095] In a work assistance system according to a fifth aspect of the present invention, in the work assistance system according to the first to fourth aspects, the controller determines the offset amount to zero in a case where the lever operation amount is less than a predetermined threshold value.

[0096] In a work assistance system according to a sixth aspect of the present invention, in the work assistance system according to the first to fifth aspects, the lever operation amount changes in accordance with a change in a position of the operation lever, and the controller resets the offset amount in a case where the operation lever returns to a default position.

[0097] In a work assistance system according to a seventh aspect of the present invention, in the work assistance system according to the first to sixth aspects, the controller determines the offset amount on a basis of an integrated value of the lever operation amount.

[0098] In a work assistance system according to an eighth aspect of the present invention, in the work assistance system according to the seventh aspect, the controller allows determination as to whether the work is ground leveling work on the target construction topography, and resets the offset amount in a case of determining that the ground leveling work of one cycle set in advance has ended.

Claims

1. A work assistance system configured to assist work of a work machine including

a machine body, and

an attachment that is operatively attached to the machine body and performs work, the work assistance system comprising:

an operation lever that receives input of an operation for operating the attachment; and

a controller,

wherein the controller determines an offset amount from a target construction topography as a finishing target to a work target topography as a target of the work of the work machine in accordance with at least a lever operation amount input to the operation lever.

2. The work assistance system according to claim 1, further comprising an attachment actual speed detector that detects an actual speed of the attachment, wherein the controller determines the offset amount on a basis of the lever operation amount and the actual speed.

3. The work assistance system according to claim 1, wherein

the attachment includes a distal end attachment,

the work assistance system further comprises a distance detector that detects a distance from the target construction topography to the distal end attachment, and

the controller determines the offset amount on a basis of the lever operation amount and the distance.

4. The work assistance system according to claim 1, wherein the controller determines the offset amount to a predetermined fixed value in a case where the lever operation amount is a predetermined threshold value or more.

5. The work assistance system according to claim 1, wherein the controller determines the offset amount to zero in a case where the lever operation amount is less than a predetermined threshold value.

6. The work assistance system according to claim 1, wherein

the lever operation amount changes in accordance with a change in a position of the operation lever, and

the controller resets the offset amount in a case where the operation lever returns to a default position.

7. The work assistance system according to claim 1, wherein the controller determines the offset amount on a basis of an integrated value of the lever operation amount.

8. The work assistance system according to claim 7, wherein

the controller

allows determination as to whether the work is ground leveling work on the target construction topography, and

resets the offset amount in a case of determining that the ground leveling work of one cycle set in advance has ended.

Drawing