Driverless transport system

Abstract

Driverless transport system (11, 31, 41) with a plurality of vehicles (13) which are designed for automatically controlled driving on the floor (51) of an operating area (15), wherein the driverless transport system (11, 31, 41) has a collision avoidance system (21) comprising: at least one ground sound generator (23) which is arranged on a first vehicle (13) and is designed to generate a structure-borne sound signal (27) on the ground or is designed to generate a structure-borne sound signal (27) in the ground (51), at least one ground sound receiver (25) which is arranged on a second vehicle (13) and is designed to receive the structure-borne sound signal (27) from the ground (51), and an electronic control unit (29) which is in signal connection with the ground sound receiver (25) and is designed to detect an impending collision between the first vehicle (13) and the second vehicle (13) based on an evaluation of the structure-borne sound signal (27) received by the ground sound receiver (25).

Description

[0001] The present invention relates to a driverless transport system comprising a plurality of vehicles designed for automatically controlled driving on the floor of an operating area.

[0002] Such transport systems are used in a variety of ways to transport goods, components, intermediate products, and the like. All types of automated vehicles can be considered, such as AGVs (automated guided vehicles), industrial trucks, lifting equipment, and the like. The vehicles can be controlled via a central control unit of the transport system, for example, via radio. However, there are also driverless transport systems in which the vehicles move autonomously within the operating area, for example, using a grid navigation system.

[0003] Various precautions are known to prevent unwanted collisions between vehicles in driverless transport systems. For example, sensors can be installed on each vehicle to monitor the surroundings. However, certain sections of the operating area are often poorly or completely invisible to monitoring sensors. This can be particularly the case at intersections and junctions. Therefore, vehicles must frequently reduce their speed in such areas. However, this is associated with a reduced efficiency of the transport system.

[0004] It is also possible to use radio transmission to enable communication between the vehicles and a central control unit, providing precise route planning for each individual vehicle. However, this involves considerable effort.

[0005] It is an object of the invention to enable safe and efficient operation of driverless transport systems using simple means.

[0006] The problem is solved by a driverless transport system having the features of claim 1.

[0007] A first driverless transport system according to the invention has a collision avoidance system comprising: at least one ground sound generator arranged on a first vehicle and designed to generate a structure-borne sound signal on the ground or is designed to generate a structure-borne sound signal in the ground, at least one ground sound receiver arranged on a second vehicle and designed to receive the structure-borne sound signal from the ground, and an electronic control unit which is in signal communication with the ground sound receiver and is designed to detect an impending collision between the first vehicle and the second vehicle based on an evaluation of the sound signal received by the ground sound receiver.

[0008] The first vehicle is therefore able to transmit information concerning the vehicle to the electronic control unit via sound waves conducted through the ground. The electronic control unit can, for example, be located on another vehicle, which is warned of the approach of the first vehicle, for example via the ground sound. In principle, the electronic control unit can also be a central control unit of the transport system, which is informed of the status of the first vehicle via ground sound and, in turn, transmits control commands to at least one other vehicle, in particular via ground sound, to avoid collisions. One advantage of signal transmission via structure-borne sound is that it is not significantly impeded by walls and other objects. There is also no noise pollution in the operating area, as would be the case with signal transmission via airborne sound.The propagation of structure-borne sound waves on the ground surface decreases quadratically with the distance from the sound source, meaning that the structure-borne sound signal can only be detected by the ground sound receiver in a relatively small area around the ground sound generator. This is advantageous in that unnecessary signal transmissions are avoided. For example, it makes it possible for the ground sound receiver to only detect the structure-borne sound signal from a vehicle in the immediate vicinity, thus only checking for imminent collision when necessary.

[0009] According to one embodiment of the invention, the collision avoidance system comprises a set of multiple ground sound generators and multiple ground sound receivers, with at least one ground sound generator and at least one ground sound receiver being arranged on each of the vehicles. An electronic control unit can also be arranged on each of the vehicles, which is in signal communication with the ground sound generator and / or the ground sound receiver of the respective vehicle. In this embodiment, the vehicles of the transport system can communicate with each other in any manner as needed. A central control unit is then not absolutely necessary.

[0010] The electronic control unit can be configured to change the speed of at least one of the vehicles upon or after detecting an impending collision and / or to stop at least one vehicle upon or after detecting an impending collision. In this way, collisions can be prevented without requiring the issuance of a warning signal.

[0011] A further embodiment of the invention provides that at least two ground sound generators or ground sound receivers are arranged at a distance from one another on at least one of the vehicles, wherein the electronic control unit of a vehicle is configured to determine the position of the vehicle or another vehicle based on a comparison of the structure-borne sound signals generated by the at least two ground sound generators and / or based on a comparison of the structure-borne sound signals received by the at least two ground sound receivers. Thus, a vehicle can be located using ground sound.

[0012] The structure-borne sound signal can include data to be transmitted from the first vehicle to the second vehicle. Data can then be transmitted between two vehicles via ground sound waves.

[0013] The structure-borne sound signal can indicate an identifier of a first vehicle and / or a current position of the first vehicle and / or a current speed of the first vehicle and / or a current direction of the first vehicle. Thus, for example, the control unit of a second vehicle can easily and quickly determine whether or not the first vehicle poses a collision risk.

[0014] It can be provided that the ground sound generator is arranged on a wheel of the first vehicle and / or that the ground sound receiver is arranged on a wheel of the second vehicle. This eliminates the need for a separate contact element for transmitting the ground sound signals from or to the vehicle. The ground sound generator and / or the ground sound receiver can also be part of the wheel itself. In principle, a sound pickup in the form of a trailing wire can also be guided over the ground. The ground sound receiver can further comprise an optical sensor, such as a laser sensor, which scans the ground and thus detects the ground sound waves.

[0015] A specific embodiment of the invention provides that the floor sound generator is a vibration module with a contact surface for contact with the floor. The vibration module can comprise a motor that drives a disc with an unbalanced mass. Such vibration modules can be provided relatively inexpensively.

[0016] The ground sound sensor can be an acceleration sensor or a vibration sensor. Such sensors can detect even slight vibrations in the ground.

[0017] The electronic control unit can be configured to distinguish between, for example, longitudinal ground sound waves, transverse ground sound waves, Rayleigh waves, Love waves, and flexural waves. This facilitates the determination of the transmission position and the suppression of interference. Preferably, the structure-borne sound generator is designed to generate surface waves such as Rayleigh waves, Love waves, and flexural waves, as these have a particularly long range. Accordingly, it is also preferred that the ground sound receiver be specifically designed to receive surface waves such as Rayleigh waves, Love waves, and flexural waves.

[0018] The invention also relates to a driverless transport system comprising at least one vehicle designed for automatically controlled driving on the floor of an operating area and comprising a set of marking elements to be arranged on the floor from which navigation information can be obtained.

[0019] The marking elements on the ground serve to orient the autonomous vehicle within an operating area defined by the grid. The navigation information enables the vehicle to execute a targeted journey from a starting point to an end point.

[0020] However, such grid navigation systems are relatively complex, especially for large areas of operation.

[0021] According to the invention, at least one and preferably each of the marking elements comprises a ground sound generator which is designed to generate a structure-borne sound signal indicating navigation information on or in the ground, and / or a ground sound receiver which is designed to receive a structure-borne sound signal indicating navigation information from the ground.

[0022] The marking elements can easily transmit their position to passing vehicles via ground sound. For this purpose, the at least one vehicle can have a ground sound receiver designed to receive the structure-borne sound signal from the ground. The vehicles of the driverless transport system can use the positions for navigation. On the other hand, a marking element can, if necessary, receive a structure-borne sound signal from a vehicle via a ground sound receiver and forward it to a control center, for example for position control. For this purpose, the at least one vehicle can have a ground sound generator designed to generate a structure-borne sound signal on the ground or designed to generate a structure-borne sound signal in the ground. It is also possible for the marking elements to transmit control commands to the vehicles.For example, a marking element can be linked to a loading station and designed to signal to surrounding vehicles that more or fewer vehicles are needed for loading. The marking elements are preferably permanently attached to the ground, for example, screwed to the ground or embedded in the ground.

[0023] The driverless transport system described here, which comprises the set of marking elements to be arranged on the ground, can moreover preferably be designed as described above for the first invention and its embodiments and for this purpose can in particular also have a plurality of vehicles.

[0024] Furthermore, the invention relates to a driverless transport system with at least one vehicle which is designed for automatically controlled driving on the floor of an operating area, with a movable robot arm for loading and / or unloading the vehicle, wherein at least one structure-borne sound generator is arranged on the movable robot arm, which is designed to transmit a structure-borne sound signal to the vehicle when the robot arm touches the vehicle, and / or wherein at least one structure-borne sound receiver is arranged on the movable robot arm, which is designed to receive a structure-borne sound signal from the vehicle when the robot arm touches the vehicle.

[0025] The robot with the robot arm can thus communicate easily and quickly with the vehicle. For this purpose, the at least one vehicle can have a structure-borne sound receiver designed to receive structure-borne sound signals. For example, the robot arm can signal the vehicle that the charging process is complete. Alternatively or additionally, the vehicle in question could signal the robot that the permissible total weight of the vehicle has been reached. For this purpose, the at least one vehicle can have a structure-borne sound generator designed to generate structure-borne sound signals.

[0026] The driverless transport system comprising a robot or robot arm can, moreover, preferably be designed as described above for the first invention and its embodiments and, for this purpose, can in particular also comprise a plurality of vehicles.

[0027] Further developments of the invention can also be found in the dependent claims, the description and the accompanying drawings.

[0028] The invention is described below by way of example with reference to the drawings. Fig. 1 is a simplified plan view of a driverless transport system according to a first embodiment of the invention. Fig. 2 is a simplified plan view of a driverless transport system according to a second embodiment of the invention. Fig. 3 shows a transport system according to a third embodiment of the invention from the side. Fig. 4 shows a ground sound generator on a wheel of a vehicle of a transport system according to the invention.

[0029] The Fig. The driverless transport system 11 shown in Figure 1, designed according to an embodiment of the invention, serves to guide objects (not shown) such as goods or components to predetermined destinations within a limited operating area 15, such as a production or warehouse, by means of several vehicles 13. The vehicles 13 are designed for automatically controlled travel on the floor of the operating area 15. High-bay racks 17 or other obstacles may be located in the operating area 15, for example. Fig. 1 shows two vehicles 13 as an example, whereby the driverless transport system 11 may also have more than two vehicles 13. The current directions of travel 19 of the vehicles 13 are shown in Fig. 1 indicated by arrows.

[0030] At the Fig. In the situation depicted in Figure 1, there is a risk of collision between vehicles 13 if they continue their journey unchanged. Any monitoring sensors, such as cameras, mounted on vehicles 13 are of limited use due to the restricted visibility caused by the high-bay racks 17.

[0031] The driverless transport system 11 is therefore equipped with a collision avoidance system 21 based on the transmission of ground sound waves. In particular, a ground sound generator 23 and a ground sound receiver 25 are arranged on each of the vehicles 13. The ground sound generators 23 are designed to generate a structure-borne sound signal on or in the ground. For example, each of the ground sound generators 23 can comprise a vibration module provided in the region of a wheel (not shown) of the vehicle 13. The ground sound receivers 25 can be acceleration sensors or vibration sensors provided in the region of the wheels of the vehicles 13.

[0032] Each of the ground sound generators 23 generates a specifically coded structure-borne sound signal 27 on or in the ground, which indicates an identification of the respective vehicle 13, a current position of this vehicle 13, and, if applicable, its current speed. The ground sound generators 23 are preferably designed to generate structure-borne sound signals 27 in the form of surface waves. As shown in Fig. 1, the transmission of floor noise is not hindered by the high shelves 17.

[0033] Each of the vehicles 13 comprises an electronic control unit 29, which is in signal connection with the ground sound generator 23 and with the ground sound receiver 25 of the respective vehicle 13. According to the example of Fig. 1, the ground sound generator 23 of the upper left vehicle 13 in the image emits a structure-borne sound signal 27, which can be received by the ground sound receiver 25 of the lower right vehicle 13 in the image. The electronic control unit 29 of the lower right vehicle 13 is able to detect the impending collision between the vehicles 13 based on an evaluation of the structure-borne sound signal 27 received by the ground sound receiver 25. The electronic control unit 29 can then issue a control command that causes the lower right vehicle 13 to slow down. Alternatively, to avoid a collision, the ground sound generator 23 of the lower right vehicle 13 can also emit a structure-borne sound signal 27 (not shown), which instructs the upper left vehicle 13 to slow down.The decision as to which of the vehicles 13 is slowed down or stopped may be based on priority rules stored in memory devices of the electronic control units 29. Acceleration of one of the vehicles 13 may also be considered to avoid a collision.

[0034] The 13 vehicles can communicate autonomously with each other via ground-based sound, so a central control unit is not absolutely necessary. However, one can be provided additionally if necessary.

[0035] According to an embodiment not shown, several ground sound generators 23 and / or ground sound receivers 25 are arranged at a distance from one another on the vehicles 13. In this embodiment, it is possible for one vehicle 13 to be located by another vehicle 13.

[0036] The Fig. The driverless transport system 31 shown in Figure 2, designed according to an alternative embodiment of the invention, has a set of marker elements 35 that are attached to the ground. Each of the marker elements 35 has both a ground sound generator 23 and a ground sound receiver 25. Thus, it is possible for signals to be exchanged between the vehicle 13 and the marker elements 35 via ground sound. For example, the marker elements 35 can report their positions to the vehicle 13, and the vehicle 13 can notify a marker element 35 of an approach.

[0037] The Fig. 3, designed according to a further alternative embodiment of the invention, comprises a vehicle 13 with wheels 37 and a structure-borne sound generator 38 and a structure-borne sound receiver 39. Furthermore, the Fig. The driverless transport system 41 shown in Figure 3 is provided with a robot 45 for loading and unloading the vehicle 13. The robot 45 has a base 47 and a movable robot arm 48 with an end effector 49. The end effector 49 of the robot arm 48 is designed for contact with the vehicle 13 and here has the structure-borne sound generator 38 and the structure-borne sound receiver 39. Thanks to the structure-borne sound generator 38 and the structure-borne sound receiver 39, information can be exchanged between the vehicle 13 and the robot 45. For example, the robot 45 can signal when the loading or unloading process is complete. Likewise, the vehicle 13 can output a signal to the robot 45 when the permissible total weight of the vehicle 13 is reached during loading.

[0038] A particularly simple embodiment of a floor sound generator 23 is shown in Fig.4. Two metal firing pins 50 are mounted at a defined distance from each other on a wheel 37 of a vehicle (not shown in detail) of a driverless transport system. As the wheel 37 rolls along the ground 51, sound pulses 53 are generated, as shown on the time axis 54. The number and spacing of the firing pins 50 indicate the identification of the vehicle in question. The speed of the vehicle can be determined from the repetition rate of the sound pulses 53. In this case, bidirectional communication is not absolutely necessary. Right of way can also be clarified via defined rules if necessary. For example, a sequence of the identifications of all existing vehicles can be stored in a memory.

[0039] Signal transmission via ground sound is particularly advantageous in the context of driverless transport systems 11, 31, 41 because the signals are imperceptible to people present and are also unaffected by obstacles such as high-bay racks 17. Furthermore, the complexity can be significantly reduced compared to radio systems requiring approval. List of reference symbols 11 driverless transport system 13 vehicles 15 Operating area 17 high bay racks 19 current direction of travel 21 Collision avoidance system 23 floor sound generators 25 ground sound receivers 27 Structure-borne sound signal 29 electrical control unit 31 driverless transport system 35 Marking element 37 wheels 38 structure-borne sound generators 39 structure-borne sound receivers 41 driverless transport system 45 robots 47 Base 48 Robot arm 49 End effector 50 firing pins 51 Floor 53 sound pulse 54 Timeline

Claims

[1] Driverless transport system (11, 31, 41) with a plurality of vehicles (13) which are designed for automatically controlled driving on the floor (51) of an operating area (15), wherein the driverless transport system (11, 31, 41) has a collision avoidance system (21) which comprises: at least one ground sound generator (23) which is arranged on a first vehicle (13) and is designed to generate a structure-borne sound signal (27) on the ground or is designed to generate a structure-borne sound signal (27) in the ground (51), at least one ground sound receiver (25) which is arranged on a second vehicle (13) and is designed to receive the structure-borne sound signal (27) from the ground (51), and an electronic control unit (29) which is in signal connection with the ground sound receiver (25) and is designed to detect an impending collision between the first vehicle (13) and the second vehicle (13) based on an evaluation of the structure-borne sound signal (27) received by the ground sound receiver (25). [2] Driverless transport system according to claim 1, wherein the collision avoidance system (21) comprises a set of a plurality of ground sound generators (23) and a plurality of ground sound receivers (25), wherein at least one ground sound generator (23) and at least one ground sound receiver (25) are arranged on each of the vehicles (13). [3] Driverless transport system according to claim 1 or 2, wherein the electronic control unit (29) is designed to change the speed of at least one of the vehicles (13) upon or after the detection of an impending collision and / or to stop at least one vehicle (13) upon or after the detection of an impending collision. [4] Driverless transport system according to one of the preceding claims, wherein at least two ground sound generators (23) or ground sound receivers (25) are arranged at a distance from one another on at least one of the vehicles (13), and wherein the electronic control unit (29) of a vehicle (13) is designed to determine the position of the vehicle (13) or of another vehicle (13) based on a comparison of the structure-borne sound signals (27) generated by the at least two ground sound generators (23) and / or based on a comparison of the structure-borne sound signals (27) received by the at least two ground sound receivers (25). [5] Driverless transport system according to one of the preceding claims, wherein the structure-borne sound signal (27) comprises data to be transmitted from the first vehicle (13) to the second vehicle (13). [6] Driverless transport system according to one of the preceding claims, wherein the structure-borne sound signal (27) indicates an identifier of the first vehicle (13) and / or a current position of the first vehicle (13) and / or a current speed of the first vehicle (13) and / or a current direction of the first vehicle (13). [7] Driverless transport system according to one of the preceding claims, wherein the ground sound generator (23) is arranged on a wheel (37) of the first vehicle (13) and / or wherein the ground sound receiver (25) is arranged on a wheel (37) of the second vehicle (13). [8] Driverless transport system according to one of the preceding claims, wherein the floor sound generator (23) is a vibration module with a contact surface for contact with the floor (51). [9] Driverless transport system according to one of the preceding claims, wherein the ground sound receiver (25) is an acceleration sensor or a vibration sensor. [10] Driverless transport system (31) with at least one vehicle (13) which is designed for automatically controlled driving on the ground (51) of an operating area (15), with a set of marking elements (35) to be arranged on the ground (51) from which navigation information can be obtained, wherein at least one and preferably each of the marking elements (35) comprises a ground sound generator (23) which is designed to generate a structure-borne sound signal (27) indicating navigation information on or in the ground (51), and / or wherein at least one and preferably each of the marking elements (35) comprises a ground sound receiver (25) which is designed to receive a structure-borne sound signal (27) indicating navigation information from the ground (51). [11] Driverless transport system (41) with at least one vehicle (13) which is designed for automatically controlled driving on the floor (51) of an operating area (15), with a movable robot arm (48) for loading and / or unloading the vehicle (13), wherein at least one structure-borne sound generator (38) is arranged on the movable robot arm (48), which is designed to transmit a structure-borne sound signal (27) to the vehicle (13) when the robot arm (48) touches the vehicle (13), and / or wherein at least one structure-borne sound receiver (39) is arranged on the movable robot arm (48), which is designed to receive a structure-borne sound signal (27) from the vehicle (13) when the robot arm (48) touches the vehicle (13).

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