Method of controlling the movement of an elevator car

Abstract

 The invention relates to a method of controlling the movement of an elevator car, comprising determining whether or not there is at least one passenger in the elevator car (42), and controlling the movement of the elevator car (42) taking into account the result of the determination, whether or not there is at least one passenger in the elevator car (42), wherein different maximum upward and/or downward speeds of the elevator car (42) are set, according to whether or not at least one passenger is determined to be in the elevator car (42).

Description

Field of the invention

[0001] The present application relates to elevators and elevator control systems. In particular, the application provides a method for controlling the movement of an elevator car and a corresponding elevator system.

Background of the Invention

[0002] A passenger using an elevator car, which moves vertically upwards or downwards in an elevator shaft, is subjected to a change in atmospheric pressure. Atmospheric air pressure can be described as the pressure at any given point in the earth's atmosphere. Atmospheric air pressure increases as an elevator car travels downwards, and decreases as an elevator car travels upwards. If these pressure changes occur too rapidly, they may cause passenger discomfort, specifically to the ears of a passenger.

[0003] EP 2 178 782 B1 discloses an elevator control for use with an elevator system, wherein movement of a vertically movable elevator car is controlled such that the pressure differential experienced by a passenger does not exceed a maximum pressure differential.

[0004] On the other hand, it is desirable, to be able to move elevator cars as quickly as possible, especially as buildings are becoming ever higher, and handling capacity requirements for elevator systems are becoming ever more demanding.

[0005] In view of the above, the present invention is aimed at increasing the capacity of an elevator system.

[0006] This aim is achieved by a method for controlling the movement of an elevator car comprising the features of claim 1 as well as an elevator system comprising the features of claim 5.

[0007] Using the method according to the invention, an elevator system can be operated with increased effectivity as compared to solutions known in the prior art. Especially, handling capacity can be effectively increased. According to the invention, it is essentially determined, whether at least one passenger is present in the elevator car. If this is the case, movement of the elevator car can be performed taking into account e. g. physiological limits in connection with passenger comfort. If it is determined or ascertained, however, that no passenger is present in the elevator car, the elevator car can travel at an increased speed, substantially exceeding the physiologically acceptable or comfortable speed for a passenger.

[0008] According to the invention, a maximum upward and/or downward speed of the elevator car is set, according to whether or not at least one passenger is determined, to be in the elevator car. In case the presence of a passenger is determined, an expedient maximum upward speed and/or downward speed of the elevator car is set. In case the presence of a passenger is determined, these maximum speeds will take into account physiological or comfort limits of a passenger. If it is determined that no passenger is present in the elevator car, a higher upward and/or downward speed of the elevator car can be set, for example taking into account constructional limitations of the elevator system and/or energy considerations. Typically, the maximum downward speed in case a passenger is detected will be smaller than the maximum upward speed, in case a passenger is detected.

[0009] Advantageous embodiments of the invention are the subject matter of the dependent claims.

[0010] Advantageously, a maximum upward and/or downward acceleration of the elevator car is set, according to whether or not at least one passenger is determined to be in the elevator car. Similar to speed, there are limits to physiologically acceptable accelerations, in both upward and downward direction. If it is determined that no passenger is present in the elevator car, the limits need not be observed.

[0011] Advantageously, further operational parameters of an elevator system are also taken into account for controlling the movement of the elevator car. These can especially include energy optimization, handling capacity, current or anticipated passenger load and/or current or anticipated passenger demand. For example, even if it is determined that no passenger is present in the elevator car, the movement of the elevator car can still be effected at speeds substantially lower than the acceptable maximum values for this operating condition, if, for example, current passenger load or demand is low, and an optimization of energy consumption appears expedient.

[0012] An elevator system is advantageously adapted to perform the method according to the invention. Such an elevator system comprises an elevator control as well as detection means for determining the presence or absence of at least one passenger in the elevator car.

[0013] Such means can advantageously be provided as optical, electrical or mechanical means.

[0014] Optical means for example include light curtains comprising a plurality of light emitters and a corresponding plurality of photoelectric sensors. Presence of a passenger in the elevator car will prevent light emitted by the emitters from reaching the photoelectric sensors, whereby a corresponding signal can be generated.

[0015] Optical means can also be provided as scanning range finder sensors or cameras.

[0016] Electrical means for detecting the presence of a passenger can, for example, comprise pressure sensor means included in a floor of an elevator car.

[0017] Also, such electric means can comprise weight measuring means.

[0018] Further advantages and embodiments of the invention will become apparent from the description and the appended figures.

[0019] It should be noted that the previously mentioned features and the features to be further described in the following are usable not only in the respectively indicated combination, but also in further combinations or taken alone, without departing from the scope of the present invention.

[0020] The invention will now be further described with reference to the accompanying figures. The figures and detailed description that follow are intended to be merely illustrative and are not intended to limit the scope of the invention.

Figure 1 shows a schematic diagram of a preferred embodiment of an elevator system according to the invention,

Figure 2 shows a top view of a preferred embodiment of an elevator cabin useable in connection with the invention,

Figure 3 shows a further embodiment of an elevator cabin useable in connection with the invention,

Figure 4 shows a further top view of an elevator cabin useable in connection with the invention,

Figure 5 shows a side view of a preferred embodiment of an elevator cabin, and

[0021] FIG. 1 depicts an exemplary elevator system 40 including multiple elevator cars 42 positioned within a plurality of elevator shafts 44. Elevator cars 42 travel vertically within respective shafts 44 and stop at a plurality of landings 46. As depicted in the example, each of the various landings 46 includes an external destination entry device 48. Elevator cars 42 include internal destination entry devices 49. Examples of destination entry devices include interactive displays, computer touch screens, or any combination thereof. Still, other structures, components, and techniques for destination entry devices are well known and may be used. Yet further, traditional up/down call signals may be used at a landing. The elevator cars 42 are suspended by means of suspension ropes 43. For example, the elevator cars 42 can interact with counterweights (not shown), which are also suspended from the suspension ropes 43. Traction sheaves driven by hoist motors, which are typically used to drive such elevator systems, are schematically shown and designated 47. Be it noted that the principals of this invention can be used in any type of elevator, and the invention is not limited in any way to suspended elevator systems.

[0022] As also shown in Figure 1, a controller 50 is provided, which communicates with the elevator system 40. Especially, the controller 50 governs the movement of elevator cars 42, and operates to adjust the speed, direction and jerk of elevator cars 42. Controller 50 receives suitable inputs from the elevator system 40, for example destination calls entered by a passenger, and generates corresponding movement of the elevator cars. The elevator system may use any suitable structure, component and technique to obtain and send these or other inputs to controller 50.

[0023] The controller 50 is adapted to set a maximum speed for upward and/or downward movement of elevator cars 42 in dependence on whether at least one passenger is present in the elevator car or not. In case it is determined or ascertained that a passenger is present in an elevator car 42, the controller 50 controls movement of the elevator car 42 taking into account a first maximum upward speed v1up of the elevator car, and a maximum first downward speed v1down of the elevator car. The values of v1up and v1down are chosen such that no discomfort occurs for the passenger (s). Especially, v1up will be set to 18 m/s and v1down to 10 m/s.

[0024] In case it is determined that no passenger is present in an elevator car 42, control 50 will control movement of the elevator car 42 taking into account higher upward and downward maximum speeds, referred to v2up and v2down in the following. Speeds v2up and v2down need not take into account physiological or comfort limitations of passengers, and can therefore be set substantially higher than v1up and v1down. Typically, v2down can be set at least the same value of v1up (e.g. 18 m/s), as the elevator system as such will be designed to handle this speed. Also, the speeds v2up and v2down will typically be set taking into account the height of the building, in which the elevator system is installed, as well as the drive power and the braking performance of the elevator system. Obviously, resilience and design of individual components of an elevator system will also be taken into account when setting or calculating possible maximum speeds.

[0025] Also, if it is ascertained that a passenger is present in elevator cars 42, the elevator control 50 controls movement of the elevator cars 42 taking into account maximum upward and downward accelerations, which are physiologically acceptable to a passenger. In the following, these maximum accelerations are referred to as a1up and a1down.

[0026] In case that it is ascertained that no passengers are present in an elevator car 42, elevator control 50 controls movement of the elevator car 42 taking into account increased maximum upward and downward accelerations, referred to as a2up and a2down in the following.

[0027] The implementation of the various maximum speeds and accelerations as described above allows the controller 50 to increase downwards and upwards speed and acceleration of the elevator cabin 42 substantially above the comfort limit for passengers, when the cabin is empty. In this way, the handling capacity of the elevator cars 42 and the elevator system as a whole, particularly during times such as up-peak times, in which most of the downward trips of an elevator car 42 are made with empty cars, can be increased.

[0028] Referring now to Figures 2 - 5, preferred detection devices for detecting, whether passengers are present or not in an elevator car 42, will be described.

[0029] In Figure 2, a first preferred embodiment of a detection device for passengers is shown. A front wall of an elevator car 42 including doors is designated 42a. The doors are designated 52. Here, on a side wall 42b of the elevator car 42, a light curtain emitter 60 comprising a plurality of emitters is shown. A light curtain receiver 62 comprising a plurality of photoelectric sensors is provided on an opposite side 42c of elevator car 42. Hereby, a curtain of optical rays, schematically shown and designated 66, is established. In case of a passenger entering the space between light curtain emitter 60 and curtain receiver 62, i. e. the elevator car 42, at least one of the optical rays 66 will be interrupted, providing a signal in the light curtain receiver 62, which can be passed to the elevator controller 50, indicating that elevator car 42 is not empty, and that consequently the maximum upward and/or downward speed and acceleration are to be limited to values v1up, v1down, a1up, a1down.

[0030] Be it noted that it is not necessary to provide emitters and photoelectric sensors in form of a light curtain. It can be sufficient to provide an expedient number of emitters and photoelectric sensors and arrange these in an expedient way in order to sufficiently cover the space within the elevator car 42.

[0031] In Figure 3 a further embodiment for a detection device is shown. Figure 3 shows the floor 42e of elevator 42. Here, a plurality of pressure sensors 70 are provided in or on the floor 42e of the elevator car 42. In case a passenger enters the elevator car, at least one of the pressure sensors 70 will be activated, so that a corresponding signal can be passed to the control 50 indicating that the elevator car 42 is not empty. Again, the elevator controller 50 will limit upward and/or downward speed and acceleration as described above. Pressure sensors 70 can utilise different sensing principals. For example, they can be provided at piezo-electric sensors, piezo-resistor-sensors, electrical contact sensors etc. Also, the arrangement, shape and number of sensors 70 can vary, according to specific circumstances, e. g. designs, shapes or sizes of elevator cars.

[0032] A further embodiment of a detection device for passengers of a detection device for passengers is presented referring once again to figure 1. Here, elevator car 42 is supported by means of a suspension rope 43, as described above. A weight measuring device 80 is provided, which is connected to elevator car 42 on its lower side and to rope 43 on its upper side. This connection can be provided in many different ways, for example by means of an intermediate elevator car frame connected to the rope 43. Also, there are numerous possible measurement principals for this weight measurement device 80. For example, when elevator car 42 is empty, the weight measurement device 80 can provide a reference value. This reference value will be modified in case of a passenger entering the elevator car, whereby a signal can be passed to the elevator controller 50, indicating that the elevator car is not empty.

[0033] In Figure 4, a further example of a device for detection of passengers in an elevator car is shown. Figure 4 is a schematic top view of an elevator car. Here, the detection device is provided as a scanning range finder sensor 90, which is located, for example, in the centre area of a rear wall 42f of elevator car 42. Such sensors are capable of scanning angles of over 180° in one or more orientations, so that the interior of an elevator car can be monitored. In case of a passenger entering the elevator car 42, the scanning range finder sensor 104 will be able to detect the passenger and pass a signal to the elevator controller 50 indicating that the elevator car is not empty. The scanning range finder sensor 90 can be based on various technologies, such a laser, ultra sound or radio technology.

[0034] The scanning range finder sensor 90 can operate in a two-dimensional way, for example scanning a plane parallel to the floor of the elevator car. Also, it can operate in an essentially three-dimensional way, scanning the complete volume of the elevator car. It can be located, for example, in the central area of a wall of the car, for example wall 42f as shown in Figure 4. It can also be located in a corner of an elevator car. Although one sensor 90 will be sufficient for most applications, it is also conceivable to use more than one such scanning range finder sensor.

[0035] Figure 5 shows a further preferred embodiment of a passenger detection device. Figure 5 shows a side view of elevator cabin 42. A camera 100 is provided on the ceiling 42g of the elevator car 42. Camera 100 is adapted to monitor the volume of elevator car 42 and send corresponding information to the elevator controller 50, or to an additional camera controlling device (not shown). The elevator controller 50 or such a camera controlling device is adapted to compare the image provided by camera 100 with a reference background information of the empty elevator car, and to generate a signal indicating whether the cabin is empty or not. Instead of comparing images received by camera 100 with reference background information of the empty elevator car, it is also possible to use various algorithms, such as pattern matching or object segmentation algorithms, in which images are analysed in order to identify the presence of passengers inside the elevator car. Such algorithms, e. g. pattern matching, can be used to differentiate between passengers and for example objects to be transported in the elevator car. In case it e. g. is determined that an object, which is not a passenger, is present in the elevator car, the higher speeds and larger accelerations as described above could be utilised. The location as well as the number of such cameras 100 can vary, depending on specific circumstances, such as size or shape of the elevator car.

[0036] As described above, the main advantage of the present invention lies in the reduction of cycle times for high speed elevators, whereby higher handling capacities for elevator systems, especially in high rise buildings, can be provided. Such a higher capacity can lead to a reduction of necessary elevator shafts in a building.

[0037] Detection systems as described above can also be used in connection with energy saving. For example, if it is ascertained that a cabin is empty, lights could be switched off. Also, in case it was determined that an elevator car is empty, empty trips with wrong destination selection can be avoided. A typical example in this connection is if a passenger, for example by mistake or as a practical joke, presses a large number of destinations. Unnecessary movement of the cabin can be avoided, if it remains in the floor it is, as soon as the passenger has left the cabin, or if he does not even enter it.

[0038] Be it finally noted that an elevator system according to the invention is advantageously adapted to not necessarily travel at higher speeds, in case an empty elevator car is detected. Depending on current load of an elevator system, the control of the elevator system can be controlled to move elevator cars at lower speeds even if elevator cars are determined to be empty, for example to optimise or reduce energy consumption.

Claims

1. Method of controlling the movement of an elevator car, comprising the following steps:

- determining whether or not there is at least one passenger in the elevator car (42), and

- controlling the movement of the elevator car (42) taking into account the result of the determination, whether or not there is at least one passenger in the elevator car (42),

characterized in that different maximum upward and/or downward speeds of the elevator car (42) are set, according to whether or not at least one passenger is determined to be in the elevator car (42).

2. Method according to claim 1, wherein maximum upward and/or downward accelerations of the elevator car (42) are set, according to whether or not at least one passenger is determined to be in the elevator car (42).

3. Method according to any one of the preceding claims, wherein further operational parameters are taken into account for controlling the movement of the elevator car (42).

4. Method according to claim 3, wherein the further operational parameters include energy optimization, handling capacity, current or anticipated passenger load and/or current or anticipated passenger demand.

5. Elevator system having at least one elevator car (42) for vertically conveying passengers within at least one elevator shaft, comprising an elevator control (50) for controlling movement of the at least one elevator car (42),
characterized in that there are provided means (60, 62; 70; 80; 90; 100) for determining the presence or absence of at least one passenger in the elevator car (42), the elevator control (50) being adapted in such a way as to control movement of the at least one elevator car (42) in dependence on a determined presence or absence of at least one passenger in the elevator car (42).

6. Elevator system according to claim 5, wherein the elevator control (50) is adapted to perform a method according to any one of claims 1 to 5.

7. Elevator system according to claim 5 or 6, wherein the means for determining the presence or absence of at least one passenger in the elevator car are provided as optical means (60, 62; 90; 100) or as electrical means (70; 80).

Drawing