Fork-Lift Truck And Method For Operating a Fork-Lift Truck

• US 20160090284A1
• Filed: 09/22/2015
• Published: 03/31/2016
• Est. Priority Date: 09/25/2014
• Status: Active Grant

• Current Assignee: Toyota Material Handling Manufacturing Sweden AB (Toyota Motor Corporation)
• Original Assignee: BT Products AB
• Inventors: Svensson, Rune, Persson, Magnus, Frid, Hkan
• Granted Patent: US 9,828,223 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B66F 9/07 Floor-to-roof stacking devices, e.g. "stacker cranes", "retrievers"
• CPC Class Codes: B66F 9/0755 Position control; Position detectors
• CPC Class Codes: B66F 9/24 Electrical devices or systems
• CPC Class Codes: G05D 1/0225 involving docking at a fixed facility, e.g. base station or loading bay parking aids B62D15/027
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means
• CPC Class Codes: G06T 2200/04 involving 3D image data
• CPC Class Codes: G06T 2207/10012 Stereo images
• CPC Class Codes: G06T 2207/30252 Vehicle exterior; Vicinity of vehicle
• CPC Class Codes: H04N 13/204 using stereoscopic image cameras stereoscopic photography G03B35/00

Abstract

A fork-lift truck includes a load carrier, a first optical detector, an optical analysing unit, and a second optical detector. The analysing unit receives and analyses information from the second optical detector, wherein the first and second optical detector are movable together with the load carrier, and the first optical detector is positioned in relation to the load carrier, such that a first field of view includes at least a part of the load carrier and an extension of the load carrier. The second optical detector is positioned, such that a second field of view includes a predetermined volume above the load carrier The position and orientation of the second detector is calibrated in relation to a predetermined position on the fork-lift truck, in case one or more objects are positioned in the predetermined volume, at least one three-dimensional relative position can be determined.

Claims

1. A fork-lift truck comprising:

a load carrier;

a first optical detector having a first field of view;

at least one optical analysing unit receiving and analyzing information from the first optical detector; and

a second optical detector having a second field of view, wherein said at least one optical analysing unit receiving and analyzing information from the second optical detector, wherein said first and second optical detector are movable together with the load carrier and said first optical detector is positioned at a first position in relation to the load carrier, such that the first field of view, if the load carrier is empty, includes at least a part of said load carrier and an extension of the load carrier so that said first optical detector detects one or more potential objects positioned within a predetermined distance from the load carrier in the direction of the extension of the load carrier, wherein said second optical detector is positioned at a second position, such that the second field of view includes, if the load carrier is loaded, a predetermined volume above the load so that said second optical detector detects potential objects positioned within said predetermined volume, and wherein the position and orientation of said second detector is calibrated in relation to a predetermined position on said fork-lift truck, such that, in case one or more objects are positioned in the predetermined volume, at least one three-dimensional relative position can be determined by said at least one optical analysing unit between, on one side, said load and/or load carrier, and, on another side, said one or more objects positioned in the predetermined volume.

2. The fork-lift truck according to claim 1, where said second optical detector is positioned at a predetermined position and/or with a predetermined orientation in relation to the load carrier.

3. The fork-lift truck according to claim 1, where said position of said second optical detector is defined by coordinates in three dimensions and said orientation of said second optical detector is defined by at least one angle of orientation in relation to said predetermined position on said fork-lift truck.

4. The fork-lift truck according to claim 1, where the first and the second optical detector comprise a 3D-camera.

5. The fork-lift truck according to claim 1, where said one or more objects positioned in the predetermined volume comprise at least one of racking, load on a racking, and pallet, and/or where said one or more potential object positioned within a predetermined distance from the load carrier in the direction of the extension of the load carrier comprise at least one of racking, load on a racking, and pallet.

6. The fork-lift truck according to claim 1, wherein the fork-lift truck further comprises a load carrier control unit, wherein said at least one optical analysing unit is arranged to transfer information relating to said determined at least one three-dimensional relative position to said load carrier control unit, wherein said load carrier control unit is arranged to process said transferred information and to adjust at least one of position, orientation and movement of said load carrier based on said transferred information.

7. The fork-lift truck according to claim 6, wherein said load carrier unit is arranged to perform said adjustment of position and/or movement of said load carrier in at least one.

8. The fork-lift truck according to claim 6, wherein at least one of said optical detectors is arranged to detect a pallet of an object within said predetermined distance from the load carrier in the direction of the extension of the load carrier and/or in the predetermined volume, preferably also at least one pallet tunnel of said pallet.

9. The fork-lift truck according to claim 1, wherein the predetermined volume comprises a first part located directly above the load and/or a second part located in front of the load.

10. The fork-lift truck according to claim 1, wherein said at least one optical analysing unit and/or load carrier control unit is comprised within a master control unit of the fork-lift truck.

21. A computer program product, that, when executed in an optical analysing unit of a fork-lift truck according to claim 1 or an optical analysing unit together with a load carrier control unit of a fork lift truck according to claim 1, executes the method according to claim 11.

11. A method for operating a fork-lift truck including a load carrier, a first optical detector, a second optical detector, and at least one optical analysing unit, wherein said second optical detector is calibrated in relation to a position on the fork-lift truck, preferably a position on the load carrier, the method comprising the steps of:

detecting by said first and/or second optical detector at least one object in the longitudinal direction of the load carrier and/or a potential load on the load carrier, and/or at least one object above or below the load carrier and/or a potential load;

determining at least one three-dimensional relative position between, on one side, said determined at least one object and, on the other side, the load carrier and/or the potential load; and

providing measures to adjust at least one of a position, an orientation and a movement of said load carrier based on said determined three-dimensional relative position.

12. The method for operating a fork-lift truck according to claim 11, wherein the step of detecting at least one object comprises transferring an output from said first and/or second optical detector to said at least one optical analysing unit, where said at least one optical analysing unit processes the received output to identify said at least one object.

13. The method for operating a fork-lift truck according to claim 11, wherein the step of detecting at least one object is performed within a predetermined volume.

14. The method according to claim 13, wherein size and position of said predetermined volume is chosen based on the dimensions of a load on the load carrier in case such a load is present, and/or wherein size and position of said predetermined volume is chosen based on a predetermined pallet size to be handled and/or a height of a load of a predetermined size to be handled in case no load is present on the load carrier.

15. The method for operating a fork-lift truck according to claim 11, used when a load is present on the load carrier, wherein the method further comprises

lifting the load carrier with the load on said load carrier,

in case at least one object is detected above said load by said second optical detector, and that at least one of the detected at least one object protrudes in a lifting path of said load carrier with the load, provide measures to avoid collision between said at least one object and said load carrier with the load.

16. The method for operating a fork-lift truck according to claim 11, used when no load is present on the load carrier, wherein the method further comprises:

lifting the load carrier;

in case at least one object is detected above said load carrier by said first optical detector, and that at least one of the detected at least one object protrudes in a lifting path of said load carrier, provide measures to avoid collision between said at least one object and said load carrier.

17. The method for operating a fork-lift truck according to claim 11, used when no load is present on the load carrier and the fork-lift truck is positioned in front of a racking where load should be picked up, the method further comprising:

lifting the load carrier to a predetermined position where a load to pick up is expected;

determining the load to pick up, preferably potential pallet tunnels of that load, among the detected at least one object;

assuring that said determined at least one three-dimensional relative position comprises at least one three-dimensional relative position between the load to pick up and the load carrier, preferably at least one three-dimensional relative position between potential pallet tunnels of the load and the load carrier;

providing measures to adjust at least one of a position and an orientation of said load carrier based on said determined three-dimensional relative position, providing these measures in such a way that the load carrier is positioned in a pick-up position in front of the load to pick up, such that a compensation for racking misalignment and/or deflection, floor misalignment, and mast inclination and/or deflection is achieved; and

loading the load on the load carrier, preferably by entering the load carrier in the pallet tunnels, and picking up the load.

18. The method for operating a fork-lift truck according to claim 11, used when a load is present on the load carrier and the fork-lift truck is positioned in front of a racking where a load is to be deposited, the method further comprising:

lifting the load carrier to a predetermined position, where it is assumed that said second optical detector can detect whether there are any protruding objects in a volume where the load is to be deposited;

determining a predetermined object with a predetermined relation to said racking and to said volume where the load is to be deposited among the detected at least one object;

assuring that said determined at least one three-dimensional relative position comprises at least one three-dimensional relative position between the load carrier and said predetermined object with the predetermined relation to said racking and to said volume;

providing measures to adjust at least one of a position, and an orientation of said load carrier based on said determined three-dimensional relative position, providing these measures in such a way that a compensation for racking misalignment and/or deflection, floor misalignment, and mast inclination and/or deflection is achieved and such that said second optical detector can detect whether there are any protruding objects in the volume where the load is to be deposited;

detecting by said second optical detector whether there are any protruding objects in the volume where the load is to be deposited; and

in case no protruding objects have been found in the volume where the load is to be deposited, positioning the load carrier in a position where the loader can be deposited and depositing the load into the racking.

19. The method for operating a fork-lift truck according to claim 18, where said predetermined object comprises at least one of a side of a racking and a landmark.

20. The method for operating a fork-lift truck according to claim 18, further comprising the following steps after the load has been deposited:

retracting the load carrier from the load;

after the load carrier has been retracted by at least a predetermined distance from the load, detect the load, preferably a potential pallet of the load, and the racking by said first optical detector; and

determine a three-dimensional relative position between the load, preferably the potential pallet of the load, and the racking.