Method for transporting an object

Abstract

The invention relates to a method for transporting an object (50) by means of a first autonomous transport vehicle (11) and a second autonomous transport vehicle (12), wherein the transport vehicles (11, 12) are moved in a direction of travel (F); the object (50) is supported on a first supporting area (15) of the first transport vehicle (11) and on a second supporting area (16) of the second transport vehicle (12); the object (50) is mounted so as to be movable relative to the second supporting area (16) in a conveying direction (X); the second supporting area (16) is oriented in such a manner that the conveying direction (X) at least approximately corresponds to the direction of travel (F); the second supporting area (16) has a front end area (18) and a rear end area (19); a position of the object (50) on the second supporting area (16) is captured by at least one position sensor (24); and a captured deviation of the position of the object (50) in the conveying direction (X) from a target position is compensated for by changing a speed of the second transport vehicle (12).

Description

[0001] Method for transporting an object

[0002] Description:

[0003] The invention relates to a method for transporting an object by means of a first autonomous transport vehicle and a second autonomous transport vehicle.

[0004] DE 102016 013645 A1 discloses a transport system and a method for operating the transport system for transporting objects. The transport system comprises two mobile units and a transport frame, with the transport frame resting on the mobile units.

[0005] DE 102010 021 706 B4 discloses a vehicle with conveyor rollers for transporting objects. The vehicle also has a secondary winding, which can be used to supply the vehicle with power inductively from a current-carrying primary conductor laid in the ground.

[0006] US 2015 / 142249 A1 discloses a robot system for transporting an elongated object. The robot system comprises a first robot and a second robot, each of which has a mechanism for compensating for positioning errors.

[0007] EP 2 062 837 A1 discloses a method for operating an industrial truck. The industrial truck comprises several autonomously operable transport units that can be combined to form a network.

[0008] DE 102020 212 464 A1 discloses a modular robot system for transporting an object. The robot system comprises at least two autonomous robot units, each of which has a connecting means for connecting to the object.

[0009] EP 3 070 564 B1 discloses a method for forming a vehicle network consisting of two autonomous vehicles. A communication connection is established between the bus systems of the vehicles, and the drive devices of the second vehicle are controlled by the control device of the first vehicle. The invention is based on the object of further developing a method for transporting an object.

[0010] The object is achieved according to the invention by a method for transporting an object having the features specified in claim 1. Advantageous embodiments and further developments are the subject of the subclaims.

[0011] According to the inventive method for transporting an object by means of a first autonomous transport vehicle and a second autonomous transport vehicle, the first transport vehicle and the second transport vehicle are moved in a direction of travel. The object to be transported rests on a first support area of ​​the first transport vehicle and on a second support area of ​​the second transport vehicle. The object is mounted so as to be movable in a conveying direction relative to the second support area. During transport, the second support area is aligned such that the conveying direction at least approximately corresponds to the direction of travel. The second support area has a front end area facing the first transport vehicle and a rear end area facing away from the first transport vehicle. The position of the object on the second support area is detected by at least one position sensor.A detected deviation of the position of the object in the conveying direction from a target position is compensated by a change in the speed of the second transport vehicle in the direction of travel.

[0012] The method according to the invention allows the transport of a relatively long object, which in particular is significantly longer than the support area of ​​a single transport vehicle and which therefore cannot be transported by a single transport vehicle. Such an object is, for example, a conduit pipe. A mechanical connection between the transport vehicles, for example, by means of a transport container, is not required. Even with slight deviations in the speeds of the transport vehicles from one another, no significant force is exerted on the object by the support areas in the transport direction.

[0013] According to a preferred embodiment of the invention, upon detection of a deviation in the position of the object toward the front end region, the speed of the second transport vehicle is increased, and upon detection of a deviation in the position of the object toward the rear end region, the speed of the second transport vehicle is reduced. This compensates for a detected deviation in the position of the object in the conveying direction from the desired position.

[0014] According to an advantageous development of the invention, the second transport vehicle has a conveyor unit for conveying piece goods in the conveying direction. The conveyor unit forms the second support area. Such a conveyor unit allows the object to be stored on the second support area in a manner that is movable in the conveying direction.

[0015] According to an advantageous embodiment of the invention, the conveyor unit comprises a plurality of conveyor rollers, each of which is rotatable about a roller axis extending in a transverse direction. The conveyor rollers form the second support area.

[0016] According to an advantageous embodiment of the invention, the conveyor unit comprises a conveyor belt that is placed around several rollers, each of which is rotatable about a roller axis extending in a transverse direction. The conveyor belt forms the second support area.

[0017] According to an advantageous embodiment of the invention, the at least one position sensor is designed as a rotary encoder for detecting the angular position of at least one conveyor roller or at least one roller. By rotating a conveyor roller or a roller, a deviation in the position of the object in the conveying direction can be relatively easily detected.

[0018] According to an advantageous embodiment of the invention, the at least one position sensor is designed as an optical sensor for detecting the object resting on the second support area. The optical sensor allows contactless detection of any deviation in the position of the object in the conveying direction.

[0019] According to an advantageous development of the invention, the second support area is pivotable about a pivot axis running in a vertical direction relative to a base body of the second transport vehicle. The second support area is aligned by pivoting about the pivot axis such that the conveying direction corresponds at least approximately to the direction of travel. This also allows the transport vehicles to corner while transporting the object, with no significant force being exerted on the object by the support areas at right angles to the transport direction. According to an advantageous development of the invention, the second transport vehicle comprises a drive unit with at least one traction motor and with wheels. The wheels are each pivotable about a steering axis running in a vertical direction relative to a base body of the second transport vehicle and relative to the second support area.The second support area is aligned by pivoting the wheels around the steering axis in such a way that the conveying direction at least approximately corresponds to the direction of travel. This allows the transport vehicles to negotiate curves while transporting the object, with no significant force being exerted on the object by the support areas perpendicular to the transport direction.

[0020] According to a preferred embodiment of the invention, the transport vehicles each comprise a drive unit with at least one traction motor and with wheels, an energy storage device for supplying the drive unit, a control unit for controlling the drive unit, at least one distance sensor for detecting a distance to an object and for detecting a direction in which the object is located, at least one position sensor for determining a current position and a communication unit for wireless communication via a radio network.

[0021] The distance sensor and the position sensor are used primarily for the navigation of transport vehicles. The distance sensor allows the detection of stationary objects marked on a map, thus determining the current position of the transport vehicle on the map. The distance sensor also allows the detection of moving objects, such as other transport vehicles.

[0022] According to a preferred development of the invention, a central computer transmits an order to transport an object to a destination via the radio network to the first transport vehicle and to the second transport vehicle. The control unit of the first transport vehicle calculates a first movement trajectory to the destination. The control unit of the second transport vehicle calculates a second movement trajectory to the destination. The drive unit of the first transport vehicle is controlled by the control unit of the first transport vehicle such that the first transport vehicle is moved along the first movement trajectory to the destination. The drive unit of the second transport vehicle is controlled by the control unit of the second transport vehicle such that the second transport vehicle is moved along the second movement trajectory to the destination.After transmitting the order, the transport vehicles move autonomously. This eliminates the need for error-prone communication between the transport vehicles while transporting the object. If the destination can be reached by a straight path, the direction of travel is aligned with the movement trajectories. If cornering is required to reach the destination, the current direction of travel corresponds to a tangent to the respective movement trajectory.

[0023] The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art.

[0024] The invention will now be explained in more detail with reference to the accompanying drawings. The invention is not limited to the exemplary embodiments shown in the drawings. The drawings only represent the subject matter of the invention schematically. They show:

[0025] Figure 1 : a schematic side view of two transport vehicles transporting an object and

[0026] Figure 2: a schematic representation of components of a transport vehicle.

[0027] Figure 1 shows a schematic side view of a first autonomous transport vehicle 11 and a second autonomous transport vehicle 12 transporting an object 50 within a technical facility. The technical facility is an industrial application, for example, a production plant or a logistics center. In this case, the object 50 is a conduit pipe. The transport vehicles 11, 12 are located on a level floor within the technical facility.

[0028] The transport vehicles 11, 12 are autonomously driving vehicles. The transport vehicles 11, 12 are designed similarly and each comprise a base body 14. In the illustration shown here, the transport vehicles 11, 12 both move on the said floor in one direction of travel and are offset from each other in the direction of travel F.

[0029] A vertical direction Z is perpendicular to the flat ground. Any direction perpendicular to the vertical direction Z represents a horizontal direction. The direction of travel F is perpendicular to the vertical direction Z and thus represents a horizontal direction.

[0030] Each of the transport vehicles 11, 12 comprises a conveyor unit 22 for conveying piece goods in a conveying direction X. In this case, the conveyor unit 22 comprises a plurality of conveyor rollers, each having a hollow cylindrical roller body. The conveyor rollers are each rotatable about a roller axis extending in a transverse direction Y. The roller axes of the conveyor rollers thus run parallel to one another in the transverse direction Y. The conveyor rollers are arranged offset from one another in the conveying direction X.

[0031] The transverse direction Y runs at right angles to the conveying direction X. The conveying direction X and the transverse direction Y run at right angles to the vertical direction Z and thus represent horizontal directions. The transverse direction Y and the conveying direction X are each defined for a transport vehicle 11, 12 and depend on the orientation of the respective transport vehicle 11, 12.

[0032] In the illustration shown here, the transport vehicles 11, 12 are arranged such that the conveying direction X of the first transport vehicle 11 runs parallel to the conveying direction X of the second transport vehicle 11, and such that the transverse direction Y of the first transport vehicle 11 runs parallel to the transverse direction Y of the second transport vehicle 11. The conveying directions X of the transport vehicles 11, 12 run parallel to the direction of travel F.

[0033] The transport vehicles 11, 12 each comprise a drive unit 40 for driving the transport vehicles 11, 12 on the ground. The drive unit 40 comprises a traction motor, a transmission, and a plurality of wheels 42. The traction motor drives the wheels 42 via the transmission. Alternatively, it is conceivable for the drive unit to comprise a plurality of traction motors, with each traction motor driving exactly one wheel 42.

[0034] The drive unit in this case comprises two front wheels 42, which are arranged offset from one another in the transverse direction Y, and two rear wheels 42, which are also arranged offset from one another in the transverse direction Y. The front wheels 42 are arranged offset from the rear wheels 42 in the conveying direction X. The wheels 42 are each pivotable relative to the base body 14 about a steering axis extending in the vertical direction Z.

[0035] The wheels 42 are each rotatable about a rotational axis extending in a horizontal direction. The orientation of the rotational axes depends on the respective pivot angle about the steering axis. The transport vehicles 11, 12 are thus capable of moving on the ground in any horizontal direction and of rotating about a vertical axis extending in the Z direction.

[0036] The conveyor unit 22 of the first transport vehicle 11 forms a first support area 15. In particular, the conveyor rollers of said conveyor unit 22 form the first support area 16. The conveyor unit 22 of the second transport vehicle 12 forms a second support area 16. In particular, the conveyor rollers of said conveyor unit 22 form the second support area 16. The object 50 rests on the first support area 15 of the first transport vehicle 11 and on the second support area 16 of the second transport vehicle 12. The first support area 15 is oriented such that the conveying direction X corresponds to the direction of travel F. The second support area 16 is also oriented such that the conveying direction X corresponds to the direction of travel F.

[0037] The conveyor rollers of the conveyor unit 22 of the second transport vehicle 12 are freely rotatable. The object 50 is thus mounted so that it can move relative to the second support area 16 in the conveying direction X. The conveyor rollers of the conveyor unit 22 of the first transport vehicle 11 are blocked and thus cannot rotate. The object 50 is thus immobile relative to the first support area 15 in the conveying direction X.

[0038] The second support area 16 of the second transport vehicle 12 has a front end area 18 facing the first transport vehicle 11. The second support area 16 of the second transport vehicle 12 also has a rear end area 19 facing away from the first transport vehicle 11.

[0039] The second transport vehicle 12 further comprises a position sensor 24 for detecting the position of the object 50 resting on the second support area 16. The position sensor 24 serves, in particular, to detect a movement of the object 50 in the conveying direction X relative to the conveyor unit 22 between the front end area 18 and the rear end area 19. The first transport vehicle 11 also comprises such a position sensor 24.

[0040] The position sensor 24 is embodied here as a rotary encoder and detects an angular position of at least one conveyor roller of the conveyor unit 22. The position sensor 24 of the second transport vehicle 12 preferably detects the angular position of the conveyor roller located directly at the front end region 18 of the second support region 16. When the object 50 moves in the conveying direction X relative to the conveyor unit 22, the conveyor rollers are rotated, and the position sensor 24 detects such a change in the angular position of at least one conveyor roller.

[0041] When the first transport vehicle 11 and the second transport vehicle 12 move at the same speed in the same direction, in this case the direction of travel F, the distance between the transport vehicles 11, 12 remains constant. The position of the object 50 on the second support area 16 thus remains the same; the object 50 does not move in the conveying direction X relative to the conveying unit 22 of the second transport vehicle 12.

[0042] If the first transport vehicle 11 and the second transport vehicle 12 move briefly at different speeds, the distance between the transport vehicles 11, 12 changes. Thus, the position of the object 50 on the second support area 16 changes, and the object 50 moves in the conveying direction X relative to the conveying unit 22 of the second transport vehicle 12.

[0043] Figure 2 shows a schematic representation of components of one of the transport vehicles 11, 12, which, as already mentioned, are designed similarly in this case. The transport vehicles 11, 12 each include a control unit 30 for controlling the drive unit.

[0044] The transport vehicles 11, 12 each comprise a communication unit 20 for wireless communication via a radio network. The communication unit 20 is designed, for example, as a WLAN interface. The communication unit 20 thus enables wireless communication between several transport vehicles 11, 12, as well as between a transport vehicle 11, 12 and a central computer via a radio network.

[0045] The transport vehicles 11, 12 each comprise an electrical energy storage unit (not shown here) for supplying the drive unit with electrical energy. The electrical energy storage unit is embodied as a rechargeable battery. The electrical energy storage unit also supplies the control unit 30 and the communication unit 20 with electrical energy.

[0046] The transport vehicles 11, 12 each comprise a plurality of distance sensors 32 for detecting a distance to an object and for detecting a direction in which the object is located. The distance sensors 32 are designed, for example, as laser scanners or ultrasonic sensors. The transport vehicles 11, 12 each also comprise a position sensor 34 for determining a current position. The position sensor 34 is designed, for example, as a GPS sensor. The method for transporting the object 50 by means of the first autonomous transport vehicle 11 and the second autonomous transport vehicle 12 is explained below by way of example.

[0047] A central computer in the technical system transmits an order to transport the object 50 to a destination via the radio network to the first transport vehicle 11 and to the second transport vehicle 12. The transport vehicles 11, 12 then move to a starting area and align themselves such that their conveying directions X are aligned with each other and correspond to the expected direction of travel F. The object 50 is then placed, for example by a crane, onto the first support area 15 of the first transport vehicle 11 and onto the second support area 16 of the second transport vehicle 12.

[0048] The control unit 30 of the first transport vehicle 11 calculates a first movement trajectory to the destination. The control unit 30 of the second transport vehicle 12 calculates a second movement trajectory to the destination. The movement trajectories are calculated in such a way that the distance between the transport vehicles 11, 12 is as constant as possible during the movement to the destination. In particular, the movement should be as straight as possible and without curves.

[0049] During the movement to the destination, the drive unit 40 of the first transport vehicle 11 is controlled by the control unit 30 of the first transport vehicle 11 such that the first transport vehicle 11 is moved along the first movement trajectory to the destination. The drive unit 40 of the second transport vehicle 12 is controlled by the control unit 30 of the second transport vehicle 12 such that the second transport vehicle 12 is moved along the second movement trajectory to the destination.

[0050] If a curve has to be negotiated during the movement to the destination, the first support area 15 of the first transport vehicle 11 is aligned by pivoting the wheels 42 about the steering axis such that the conveying direction X at least approximately corresponds to the direction of travel F. Likewise, the second support area 16 of the second transport vehicle 12 is aligned by pivoting the wheels 42 about the steering axis such that the conveying direction X at least approximately corresponds to the direction of travel F. During the movement to the destination, the position of the object 50 on the second support area 16 is detected by the position sensor 24.

[0051] If a deviation in the position of the object 50 toward the front end region 18 is detected, the speed of the second transport vehicle 12 is increased, thus accelerating the second transport vehicle 12. If a deviation in the position of the object 50 toward the rear end region 19 is detected, the speed of the second transport vehicle 12 is reduced, thus braking the second transport vehicle 12.

[0052] A detected deviation of the position of the object 50 in the conveying direction X from a desired position is thus compensated by a change in the speed of the second transport vehicle 12 in the direction of travel F.

[0053] List of reference symbols

[0054] 11 first transport vehicle

[0055] 12 second transport vehicle

[0056] 14 basic bodies

[0057] 15 first edition area

[0058] 16 second support area

[0059] 18 front end area

[0060] 19 rear end area

[0061] 20 Communication unit

[0062] 22 conveyor unit

[0063] 24 Position sensor

[0064] 30 Control unit

[0065] 32 Distance sensor

[0066] 34 Position sensor

[0067] 40 drive unit

[0068] 42 wheels

[0069] 50 Item

[0070] F Direction of travel

[0071] X Conveying direction

[0072] Y transverse direction

[0073] Z vertical direction

Claims

Patent claims:

1. A method for transporting an object (50) by means of a first autonomous transport vehicle (11) and a second autonomous transport vehicle (12), wherein the first transport vehicle (11) and the second transport vehicle (12) are moved in a direction of travel (F); the object (50) rests on a first support region (15) of the first transport vehicle (11) and on a second support region (16) of the second transport vehicle (12); the object (50) is movably mounted relative to the second support region (16) in a conveying direction (X); the second support region (16) is aligned such that the conveying direction (X) at least approximately corresponds to the direction of travel (F); the second support region (16) has a front end region (18) facing the first transport vehicle (11) and a rear end region (19) facing away from the first transport vehicle (11);a position of the object (50) on the second support area (16) is detected by at least one position sensor (24); and a detected deviation of the position of the object (50) in the conveying direction (X) from a desired position is compensated by a change in the speed of the second transport vehicle (12) in the direction of travel (F); 2. Method according to claim 1, characterized in that upon detection of a deviation in the position of the object (50) in the direction of the front end region (18), the speed of the second transport vehicle (12) is increased, and that upon detection of a deviation in the position of the object (50) in the direction of the rear end region (19), the speed of the second transport vehicle (12) is reduced.

3. Method according to one of the preceding claims, characterized in that the second transport vehicle (12) has a conveyor unit (22) for conveying piece goods in the conveying direction (X), and that the conveyor unit (22) forms the second support area (16).

4. Method according to claim 3, characterized in that the conveyor unit (22) has a plurality of conveyor rollers, each of which is rotatable about a roller axis extending in a transverse direction (Y), and in that the conveyor rollers form the second support area (16).

5. Method according to claim 3, characterized in that the conveyor unit (22) has a conveyor belt which is placed around a plurality of rollers, each of which is rotatable about a roller axis running in a transverse direction (Y), and in that the conveyor belt forms the second support area (16).

6. Method according to one of claims 4 or 5, characterized in that the at least one position sensor (24) is designed as a rotary encoder for detecting an angular position of at least one conveyor roller or of at least one roller.

7. Method according to one of the preceding claims, characterized in that the at least one position sensor (24) is designed as an optical sensor for detecting the object (50) resting on the second support area (16).

8. Method according to one of the preceding claims, characterized in that the second support area (16) is pivotable about a pivot axis running in a vertical direction (Z) relative to a base body (14) of the second transport vehicle (12), and in that the second support area (16) is aligned by pivoting about the pivot axis such that the conveying direction (X) corresponds at least approximately to the direction of travel (F).

9. Method according to one of the preceding claims, characterized in that the second transport vehicle (12) comprises a drive unit (40) with at least one traction motor and with wheels (42), and in that the wheels (42) are each pivotable about a steering axis running in a vertical direction (Z) relative to a base body (14) of the second transport vehicle (12) and relative to the second support area (16), and in that the second support area (16) is aligned by pivoting the wheels (42) about the steering axis in such a way that the conveying direction (X) corresponds at least approximately to the direction of travel (F).

10. Method according to one of the preceding claims, characterized in that the transport vehicles (11, 12) each comprise a drive unit (40) with at least one traction motor and with wheels (42), an energy storage device for supplying the drive unit (40), a control unit (30) for controlling the drive unit (40), at least one distance sensor (32) for detecting a distance to an object and for detecting a direction in which the object is located, at least one position sensor (34) for determining a current position and a communication unit (20) for wireless communication via a radio network.

11. The method according to claim 10, characterized in that a central computer transmits an order to transport an object (50) to a destination via the radio network to the first transport vehicle (11) and to the second transport vehicle (12); a first movement trajectory to the destination is calculated by the control unit (30) of the first transport vehicle (11); a second movement trajectory to the destination is calculated by the control unit (30) of the second transport vehicle (12); the drive unit (40) of the first transport vehicle (11) is controlled by the control unit (30) of the first transport vehicle (11) such that the first transport vehicle (11) is moved along the first movement trajectory to the destination;and the drive unit (40) of the second transport vehicle (12) is controlled by the control unit (30) of the second transport vehicle (12) such that the second transport vehicle (12) is moved along the second movement trajectory to the destination.;

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