Carton unloader tool for jam recovery

1. A method of conveying articles on a robotic material handling system, the method comprising:

positioning a nose conveyor surface of the robotic material handling system proximate to an article pile, the nose conveyor surface being vertically-movable and having two or more parallel conveyors that are distal to and feed a rearward conveyor, the rearward conveyor being laterally narrower than the nose conveyor surface;

robotically moving one or more articles onto the nose conveyor surface from the article pile;

activating at least one of the two or more parallel conveyors of the nose conveyor surface to convey at least one article from the nose conveyor surface toward the rearward conveyor;

detecting a jammed article that is at least partially supported by the nose conveyor surface and that has failed to be fully conveyed onto the rearward conveyor by the at least one of the two or more parallel conveyors;

dislodging the jammed article by causing at least one of: (i) vertically repositioning the nose conveyor surface; and (ii) activating the at least one of the two or more parallel conveyors of the nose conveyor surface to run in a forward direction;

activating at least one parallel conveyor that is in contact with the jammed article in a rearward direction to convey a portion of the jammed article in the rearward direction; and

activating the two or more parallel conveyors in the rearward direction to convey remaining portions of the jammed article in the rearward direction.

2. The method of claim 1 , wherein detecting the jammed article comprises:

scanning the nose conveyor surface;

identifying one or more articles that are present on the nose conveyor surface within respective zones of the two or more parallel conveyors by comparing the scanned nose conveyor surface to a baseline scan of an empty nose conveyor surface;

tracking the at least one article within an identified zone of the at least one of the two or more parallel conveyors of the nose conveyor surface; and

based on tracking the at least one article, determining that the at least one article has become the jammed article by failing to be conveyed onto the rearward conveyor.

3. The method of claim 1 , wherein:

dislodging the jammed article comprises vertically repositioning the nose conveyor surface; and

activating the at least one parallel conveyor that is contact with the jammed article in the rearward direction comprises activating the at least one parallel conveyor of the nose conveyor surface and at least a portion of the rearward conveyor.

4. The method of claim 3 , wherein repositioning the nose conveyor surface comprises raising the nose conveyor surface.

5. The method of claim 3 , wherein repositioning the nose conveyor surface comprises lowering the nose conveyor surface to a homed position in alignment with the rearward conveyor.

6. The method of claim 1 , wherein:

dislodging the jammed article comprises activating at least one of the two or more parallel conveyors of the nose conveyor surface to run in the forward direction away from the rearward conveyor.

7. The method of claim 6 , further comprising:

activating at least another one of the two or more parallel conveyors simultaneously with the at least one of the two or more parallel conveyors in the rearward direction to rotate the jammed article into longitudinal alignment with the rearward conveyor.

8. A robotic material handling system for unloading articles in an article pile, the robotic material handling system comprising:

a mobile body;

a movable robotic manipulator attached to the mobile body and comprising an end effector at an end, the end effector being configured to unload one or more articles from the article pile;

a conveyor system mounted on the mobile body configured to receive the one or more articles from the end effector and to move the one or more articles towards a rear of the robotic material handling system, the conveyor system comprising:

(i) a nose conveyor surface and

(ii) a rearward conveyor,

the nose conveyor surface having two or more parallel conveyors that are distal to and feed the rearward conveyor that is laterally narrower than the nose conveyor surface;

an article detection system; and

a controller in communication with the article detection system, the mobile body, the movable robotic manipulator, and the conveyor system, the controller being configured to:

cause the nose conveyor surface of the robotic material handling system to be positioned proximate to the article pile, the nose conveyor surface being vertically-movable;

cause the movable robotic manipulator to move the one or more articles onto the nose conveyor surface from the article pile;

activate at least one of two or more parallel conveyors of the nose conveyor surface to convey at least one article from the nose conveyor surface toward the rearward conveyor;

detect a jammed article that is at least partially supported by the nose conveyor surface and that has failed to be fully conveyed onto the rearward conveyor by the at the least one of the two or more parallel conveyors; and

dislodge the jammed article by causing at least one of: (i) vertically repositioning the nose conveyor surface; and (ii) activating the at least one of the two or more parallel conveyors of the nose conveyor surface to run in a forward direction;

activating at least one parallel conveyor that is in contact with the jammed article in a rearward direction to convey a portion of the jammed article in the rearward direction; and

activating the two or more parallel conveyors in the rearward direction to convey remaining portions of the jammed article in the rearward direction.

9. The robotic material handling system of claim 8 , wherein the article detection system comprises:

one or more sensors coupled respectively to one of the mobile body and the movable robotic manipulator to scan the nose conveyor surface;

a scan processing subsystem in communication with the one or more sensors, the scan processing subsystem to detect presence and location of any articles based upon a received scan of the nose conveyor surface as compared to a baseline scan; and

wherein the controller in communication with the scan processing subsystem detects the jammed article by:

scanning, by the one or more sensors, the nose conveyor surface;

identifying, by the scan processing subsystem, one or more articles that are present on the nose conveyor surface within respective zones of the two or more parallel conveyors by comparing the scanned nose conveyor surface to a baseline scan of an empty nose conveyor surface;

tracking the at least one article within an identified zone of the at least one of two or more parallel conveyors of the nose conveyor surface; and

based on tracking the at least one article, determining that the at least one article has become the jammed article by failing to be conveyed onto the rearward conveyor.

10. The robotic material handling system of claim 8 , wherein the controller is further configured to dislodge the jammed article by vertically repositioning the nose conveyor surface to a selected one of: (i) raising the nose conveyor surface relative to the rearward conveyor; and (ii) lowering the nose conveyor surface to a homed position in alignment with the rearward conveyor, wherein activating the at least one parallel conveyor that is in contact with the jammed article in the rearward direction comprises activating the at least one parallel conveyor of the nose conveyor surface and at least a portion of the rearward conveyor.

11. The robotic material handling system of claim 8 , wherein dislodging the jammed article comprises activating at least one of the two or more parallel conveyors of the nose conveyor surface to run in the forward direction away from the rearward conveyor.

12. The robotic material handling system of claim 11 , wherein the controller is further configured to:

activate at least another one of the two or more parallel conveyors simultaneously with the at least one of the two or more parallel conveyors in the rearward direction to rotate the jammed article into longitudinal alignment with the rearward conveyor.

13. A controller of a robotic material handling system that conveys articles from an article pile, the controller comprising a computer-readable storage medium containing instructions that, when executed by a processor, cause the robotic material handling system to:

position a nose conveyor surface of the robotic material handling system proximate to the article pile, the nose conveyor surface being vertically-movable and having two or more parallel conveyors that are distal to and feed a rearward conveyor, the rearward conveyor being laterally narrower than the nose conveyor surface;

robotically move one or more articles onto the nose conveyor surface from the article pile;

activate at least one of the two or more parallel conveyors of the nose conveyor surface to convey at least one article from the nose conveyor surface toward the rearward conveyor;

detect a jammed article that is at least partially supported by the nose conveyor surface and that has failed to be fully conveyed onto the rearward conveyor by the at the least one of the two or more parallel conveyors; and

dislodge the jammed article by causing at least one of: (i) vertically repositioning the nose conveyor surface; and (ii) activating the at least one of the two or more parallel conveyors of the nose conveyor surface to run in a forward direction; and

activate at least one parallel conveyor that is in contact with the jammed article in a rearward direction.

14. The controller of claim 13 , wherein the instructions cause the robotic material handling system to detect the jammed article by:

scanning the nose conveyor surface;

identifying one or more articles that are present on the nose conveyor surface within respective zones of the two or more parallel conveyors by comparing the scanned nose conveyor surface to a baseline scan of an empty nose conveyor surface;

tracking the at least one article within an identified zone of the at least one of the two or more parallel conveyors of the nose conveyor surface; and

based on tracking the at least one article, determining that the at least one article has become the jammed article by failing to be conveyed onto the rearward conveyor.

15. The controller of claim 13 , wherein the instructions cause the robotic material handling system to:

dislodge the jammed article by vertically repositioning the nose conveyor surface to a selected one of: (i) raising the nose conveyor surface relative to the rearward conveyor; and (ii) lowering the nose conveyor surface to a homed position in alignment with the rearward conveyor; and

activate the at least one parallel conveyor that is in contact with the jammed article in the rearward direction comprises activating the at least one parallel conveyor of the nose conveyor surface and at least a portion of the rearward conveyor.

16. The controller of claim 13 , dislodging the jammed article comprises activating at least one of the two or more parallel conveyors of the nose conveyor surface to run in the forward direction away from the rearward conveyor.

17. The controller of claim 16 , wherein the instructions cause the robotic material handling system to:

activate at least another one of the two or more parallel conveyors simultaneously with the at least one of the two or more parallel conveyors in the rearward direction to rotate the jammed article into longitudinal alignment with the rearward conveyor.