AUTOMATED GUIDED VEHICLE

Abstract

The present invention relates to an automated guided vehicle for transporting and placing a load, comprising a primary environmental sensor and at least one secondary environmental sensor, wherein the transport vehicle is configured, first, using the primary environmental sensor, to detect a drop-off location for the load and the region between the drop-off location and the transport vehicle and to check said drop-off location and said region for obstacles; if no obstacle is recognized, to travel to the drop-off location; during the journey to the drop-off location, to check the route and the drop-off location for obstacles using the secondary environmental sensor.

Claims

1. An automated guided vehicle for transporting and placing a load, said automated guided vehicle comprising a primary environmental sensor and at least one secondary environmental sensor, wherein the transport vehicle is configured, first, using the primary environmental sensor, to detect a drop-off location for the load and the region between the drop-off location and the transport vehicle and to check said drop-off location and said region for obstacles; if no obstacle is recognized, to travel to the drop-off location; during the journey to the drop-off location, to check the route and the drop-off location for obstacles using the secondary environmental sensor.

2. The transport vehicle according to claim 1, wherein the transport vehicle is configured, using the primary environmental sensor, to also detect neighboring regions of the drop-off location in addition to the drop-off location and to compare the detected neighboring regions with expected neighboring regions.

3. The transport vehicle according to claim 2, wherein the transport vehicle is configured to receive the expected neighboring regions from a higher-ranking automation system.

4. The transport vehicle according to claim 1, wherein the transport vehicle is configured, when checking for obstacles by means of the primary environmental sensor, to perform a plausibility check of the measurement data acquired by the primary environmental sensor.

5. The transport vehicle according to claim 2, wherein the transport vehicle is configured to set a tolerance region around the expected neighboring regions during the plausibility check, wherein measurement points outside the tolerance region that lie in front of or behind the expected neighboring regions and/or missing measurement points are evaluated as an obstacle.

6. The transport vehicle according to claim 2, wherein the transport vehicle is configured to adapt the detected neighboring regions and the expected neighboring regions to one another.

7. The transport vehicle according to claim 6, wherein the transport vehicle is configured to adapt the detected neighboring regions and the expected neighboring regions to one another by rotation and displacement.

8. The transport vehicle according to claim 1, wherein the transport vehicle is configured to determine the length of the travel path up to the drop-off location and, during the journey to the drop-off location, to monitor the actually covered travel path by means of a driving sensor system.

9. The transport vehicle according to claim 8, wherein the driving sensor system is coupled to a wheel or an axle of the transport vehicle.

10. The transport vehicle according to claim 1, wherein the transport vehicle is configured to disregard the primary environmental sensor when approaching the drop-off location.

11. The transport vehicle at least according to claim 2, wherein the transport vehicle is configured to also disregard the secondary environmental sensor when approaching the drop-off location if the transport vehicle comes closer than a predetermined threshold value to the detected and/or expected neighboring regions.

12. The transport vehicle according to claim 8, wherein the transport vehicle is configured to also disregard the secondary environmental sensor when approaching the drop-off location if the transport vehicle comes closer than a predetermined threshold value to the detected and/or expected neighboring regions and wherein the transport vehicle is configured, after the secondary environmental sensor has been disregarded, to monitor the remaining travel path by means of the driving sensor system.

13. The transport vehicle according to claim 1, wherein the primary and/or the secondary environmental sensor comprises a 2D or 3D sensor, a laser scanner, a multi-layer laser scanner, a multi-beam scanner, a 3D camera, a radar and/or an ultrasonic sensor.

14. The transport vehicle according to claim 13, wherein the primary environmental sensor is configured as a laser scanner.

15. The transport vehicle according to claim 13, wherein the secondary environmental sensor is configured as an ultrasonic sensor.

16. The transport vehicle according to claim 1, wherein the transport vehicle is an autonomous fork-lift truck or an autonomous ground conveyor.

17. A method for placing a load at a drop-off location by means of a transport vehicle, in which first, using the primary environmental sensor, a drop-off location for the load and the region between the drop-off location and the transport vehicle are detected and checked for obstacles; if no obstacle is recognized, the transport vehicle travels to the drop-off location; during the journey to the drop-off location, the route and the drop-off location are checked for obstacles using the secondary environmental sensor.

18. The method according to claim 17, wherein the drop-off location is located in a truck or a swap body and, before the detection of the drop-off location using the primary environmental sensor, the transport vehicle moves to a position outside the truck or the swap body, from which position the drop-off location can be detected by the primary environmental sensor.

19. The method according to claim 17, wherein, in order to detect the drop-off location by means of the primary environmental sensor, the load is raised to allow the primary environmental sensor to see under the load through to the drop-off location.

Description

[0050] The invention will be described purely by way of example with reference to the drawings in the following. There are shown:

[0051] FIG. 1 schematically in a side view, a transport vehicle that approaches a swap body;

[0052] FIG. 2 the transport vehicle and the swap body in a schematic plan view;

[0053] FIG. 3 a detection of the swap body by means of the primary environmental sensor;

[0054] FIGS. 4A and 4B an adaptation of the acquired measurement values;

[0055] FIG. 5 a check for obstacles;

[0056] FIG. 6 the detection of an obstacle in accordance with a first possibility;

[0057] FIG. 7 the detection of an obstacle in accordance with a second possibility;

[0058] FIG. 8 the start of the driving of the transport vehicle into the swap body;

[0059] FIG. 9 the start of the approaching of the drop-off location by the transport vehicle;

[0060] FIG. 10 the switching off of the secondary environmental sensor; and

[0061] FIG. 11 the positioning of the load at the drop-off location.

[0062] FIG. 1 shows an automated guided vehicle, more precisely an autonomous fork-lift truck 10. The fork-lift truck 10 comprises a control unit 12 that controls a drive of the fork-lift truck 10. The control unit 12 is furthermore coupled to a primary environmental sensor in the form of a laser scanner 14 and a secondary environmental sensor that comprises two ultrasonic sensors 16. The control unit 12 is furthermore coupled to a driving sensor system 18 that is fastened to a wheel of the fork-lift truck 10 and that detects the movements of the wheel. The sensors 14, 16, 18 are coupled to the control unit 12 via data links 20.

[0063] The fork-lift truck 10 comprises a fork 22 on which a load 24 can be transported. The ultrasonic sensors 16 are arranged at both ends of the fork 22.

[0064] The laser scanner 14 is arranged such that it can look backwards under the load 24 when the load 24 is raised. Accordingly, the laser scanner 24 emits laser pulses 25 to the rear during operation to detect the environment. Via reflected laser pulses (not shown), the laser scanner 24 determines the light propagation time and, from this, the distance of objects in its measurement zone.

[0065] The ultrasonic sensors 16 emit ultrasonic waves 27 in a corresponding manner.

[0066] FIG. 1 furthermore shows a swap body 26 that is arranged on a truck trailer and driven up to a loading terminal (not shown) so that the autonomous fork-lift truck can drive into the swap body 26.

[0067] In FIG. 2, the fork-lift truck 10 and the swap body 26 are now shown in a schematic plan view. It can be seen that a plurality of unloaded pallets are already present in the swap body 26. The load transported by the fork-lift truck 10 is also a pallet that is to be positioned next to the already unloaded pallets 28.

[0068] FIG. 3 now shows that a scan of the swap body 26 and the wider surroundings first takes place by means of the laser scanner 14. The laser scanner 14 in this respect acquires a plurality of measurement points 30 that form a contour 32. Due to the scan with the primary environmental sensor, i.e. with the laser scanner 14, a detection of the drop-off location 34 and the travel path of the fork-lift truck up to the drop-off location 34 as well as the environment of the drop-off location and the path of travel, i.e. the neighboring regions, therefore takes place. Accordingly, the contour 32 therefore forms the detected neighboring regions.

[0069] The control unit 12 can receive data on the loading status of the swap body 26 from a higher-ranking automation system via a radio interface (not shown).

[0070] In FIG. 4A, the areas shown hatched are those areas that are communicated to the fork-lift truck 10 by the higher-ranking automation system as already occupied by pallets. Furthermore, the fork-lift truck 10 is informed of a drop-off location 34. In particular, X-Y coordinates of the contour of the already unloaded pallets 28 can in each case be communicated to the fork-lift truck 10 by the higher-ranking automation system. The same applies to the coordinates of the drop-off location 34.

[0071] It can be seen that the measurement or scanning of the fork-lift truck 10 by its laser scanner 14 does not completely match the contours obtained from the higher-ranking automation system.

[0072] As shown in FIG. 4B, an adaptation of the obtained contour (i.e. the expected neighboring regions) and the measured contour (i.e. the detected neighboring regions) therefore takes place. The adaptation in particular takes place by rotation (da) and displacement (dx, dy). Due to the adaptation, the drop-off location 34 and the expected neighboring regions are adapted to the reference system of the fork-lift truck 10.

[0073] After the adaptation (or even before), a check for obstacles, i.e., for example persons in the way, takes place. For this purpose, a tolerance region 36 is at least regionally set around the expected neighboring regions, as shown in FIG. 5. There are no measurement points 30 in FIG. 5 that would indicate an obstacle.

[0074] In FIG. 6, on the other hand, there are two measurement points 30 in front of the tolerance region 36 so that it can be assumed here that a person is standing in front of the already loaded pallet 28. In this case, the fork-lift truck 10 may not approach the drop-off location 34.

[0075] FIG. 7 shows another variant of recognizing a person. In the case shown in FIG. 7, the person is wearing dark trousers so that the laser scanner 14 receives almost no reflected signal from the trouser legs. In practice, this often leads to measurement values being generated further away from the laser scanner 14, which is also shown in FIG. 7. However, since no values can be located in this region since the unloaded pallet 28 is located there, this is also evaluated as the recognition of an obstacle (i.e. a person).

[0076] The ultrasonic sensors 16 remain activated until the fork-lift truck 10 has almost reached the drop-off location 34 and the already unloaded pallets 28 come so close to the ultrasonic sensors 16 that the ultrasonic sensors 16 would recognize the unloaded pallets 28 as an obstacle. At this point in time, the ultrasonic sensors 16 are switched off or disregarded, as shown in FIG. 10. The fork-lift truck 10 then travels the remaining distance up to the drop-off location 34 solely based on the driving sensor system 18 since it is now ensured that there is no obstacle between the load 24 and the already unloaded pallets 28.

[0077] If the fork-lift truck 10 now reaches the position shown in FIG. 11, the fork 22 is fully lowered to unload the load 24 at the drop-off location 34.

[0078] In this way, an automatic loading of a swap body 26 is possible, whereby any risk to persons can be ruled out.

REFERENCE NUMERAL LIST

[0079] 10 autonomous fork-lift truck [0080] 12 control unit [0081] 14 laser scanner [0082] 16 ultrasonic sensor [0083] 18 driving sensor system [0084] 20 data link [0085] 22 fork [0086] 24 load [0087] 25 laser pulse [0088] 26 swap body [0089] 27 ultrasonic waves [0090] 28 unloaded pallet [0091] 30 measurement point [0092] 32 contour [0093] 34 drop-off location [0094] 36 tolerance region