Robot trajectory control including emergency evacuation path system and method

• US 7,627,394 B2
• Filed: 12/20/2005
• Issued: 12/01/2009
• Est. Priority Date: 12/20/2005
• Status: Active Grant

• Current Assignee: KUKA Laboratories GmbH (Midea Group Co., Ltd)
• Original Assignee: KUKA Roboter GmbH (Midea Group Co., Ltd)
• Inventors: Mirza, Khalid, Volcic, Edward
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): SAMPLE, JONATHAN L
• Application Number:
  US11/313,207
• Publication Number:
  US 20070142967A1
• Time in Patent Office: 1,442 Days
• Field of Search: 700/245, 700/213, 700/177
• US Class Current: 700/245
• CPC Class Codes: B25J 9/1664 characterised by motion, path, trajectory planning
• CPC Class Codes: B25J 9/1674 characterised by safety, monitoring, diagnostic
• CPC Class Codes: G05B 2219/40521 Alternative, allowable path substitution if arm movements not possible
• CPC Class Codes: G05B 2219/50109 Soft approach, engage, retract, escape, withdraw path for tool to workpiece

Abstract

A system and process is provided for controlling a robot path of a robot including providing a main path for movement of the robot based on path data having points along the main path and providing a safe evacuation path from each point in the main path to get to a safe position. The main path is formed with safety evacuation path considerations in mind such that along any point on ride path the robot can be safely moved to a safety point or to the unload position or safe position.

Claims

1. A process for controlling a robot path of a robot during emergency evacuation from the main path, the process comprising:

providing a main path for movement of the robot, said main path having evacuation points;

moving the robot along said main path;

providing at least one final safe position and at least one safety level point, said at least one safety level point being located between one or more said evacuation points and said at least one final safe position, said at least one safety level point being associated with a plurality of said evacuation points, said at least one final safe position, said at least one safety level point and one of said evacuation points defining one or more safe evacuation paths;

moving the robot along one of said safe evacuation paths when an emergency situation exists such that the robot moves from said one of said evacuation points through said at least one safety level point to said at least one final safe position.

2. A process for controlling a robot path of a robot according to claim 1, wherein a programmer teaches the robot or sets points to form the main path with safe evacuation path considerations in mind such that along any point on the main path the robot can be safely moved to a safety point or safe position.

3. A process for controlling a robot path of a robot according to claim 1, wherein the safe evacuation path includes a safety level two point, said at least one safety level point being a safety level one point, said safety level one point and said safety level two point being located between said one or more evacuation points and said final safe position.

4. A process for controlling a robot path of a robot according to claim 1, wherein the robot has a primary motion aspect and plural axes each having a motion aspect and the main path is defined based on positions of the axes assigned to the position of the primary motion via a path table.

5. A process for controlling a robot path of a robot according to claim 4, wherein the robot has a turntable and the primary motion is the motion of the turntable with a unique position provided for each position of the turn table based on a resolution of the turn table encoder monitoring the position of the turntable.

6. A process for controlling a robot path of a multiaxial robot having a tool center point, the process comprising:

moving the tool center point along a travel path defined by a plurality of location points;

defining a first safety robot path, said first safety robot path comprising a first safety level robot position and a first final safety robot position, said first safety level robot position being associated with a first plurality of said location points of said travel path;

defining a second safety robot path, said second safety robot path comprising a second safety level robot position and a second final safety robot position, said first safety level robot position being associated with a second plurality of said location points of said travel path;

upon a need to remove the robot from the travel path moving the robot along one of said first safety robot path and said second safety robot path based on a current location point of the robot along the travel path such that the robot moves from said current location point to one of said first final safety robot position and said second final safety robot position.

7. A process according to claim 6, wherein the travel path is defined with safety markers associated with some of the location points, wherein the safety paths are associated with the safety markers and one of the safety paths is selected for the step of moving the robot along one of the safety paths based on the proximity of the current location to the safety markers.

8. A process according to claim 7, wherein the robot is moved along the travel path based on a motion aspect of the robot being designated as a primary motion with a synchronizing of motions of axes of the robot with the primary motion wherein positions of the axes are assigned to the position of the primary motion via a path table for defining the travel path.

9. A process according to claim 8, wherein the motions of axes of the robot include the secondary axes motion as the robot moves along the travel path and the synchronization of the motion of the secondary axes with the primary motion includes using position encoders provided at the path of a turntable as a primary motion.

10. A process according to claim 6, wherein the need to remove the robot from the travel path includes one of a stopping the turntable or a forced emergency stopping of the turntable before moving the robot along one of the safety paths based on the current location point of the robot along the travel path.

11. A multiaxial robot path control system, comprising:

a system memory means for storing data;

a multiaxial robot with turntable;

a control unit for moving a tool center point along a travel path defined by location points saved in said memory means; and

a plurality of safety paths saved in said memory means, each safety path comprising at least one safety level point and at least one final safe position, said at least one safety level point being associated with a plurality of location points of the travel path, said at least one safety level point being arranged between said at least one final safe position and said plurality of location points of the travel path, wherein upon a need to remove the robot from the travel path, the control unit moves the robot along one of the safety paths based on a current location point of the robot along the travel path such that the robot moves to one of said final safe positions.

12. A system according to claim 11, wherein the travel path is defined with safety markers associated with some of the location points, wherein the safety paths are associated with the safety markers and one of the safety paths is selected for moving the robot along one of the safety paths based on the proximity of the current location point to the safety markers.

13. A system according to claim 12, wherein the robot is moved along the travel path based on a motion aspect of the robot being designated as a primary motion with a synchronizing of motions of axes of the robot with the primary motion wherein positions of the axes are assigned to the position of the primary motion via a path table for defining the travel path.

14. A system according to claim 13, wherein the motions of axes of the robot include secondary axes motion as the robot moves along the travel path and the synchronization of the motion of the secondary axes with the primary motion includes using position encoders provided at the path of a turntable as a primary motion.

15. A system according to claim 14, wherein the need to remove the robot from the travel path includes one of a stopping the turntable or a forced emergency stopping of the turntable before moving the robot along one of the safety paths based on the current location point of the robot along the travel path.