Robot arm and method of controlling robot arm to avoid collisions
AssigneeAgilent Technolgies, Inc.
InventorPrasad P. NAIR
Life of this patent
Estimating the term…
Abstract
A method of automatically controlling an extendable robot arm to avoid collisions while returning to a first position from a second position includes periodically storing locations of the robot arm as the robot arm moves along a forward path from the first position to the second position; applying heuristic algorithms to the stored locations to determine a return path to the first position, the return path including at least a portion of a retrace path retracing the stored locations of the forward path; and controlling the robot arm to return to the first position using the determined return path.
Claims20
A method of automatically controlling an extendable robot arm to avoid collisions while returning to a first position from a second position, the method comprising:
- periodically storing locations of the robot arm as the robot arm moves along a forward path from the first position to the second position;
- applying a plurality of heuristic algorithms to the stored locations to determine a return path to the first position, the return path including at least a portion of a retrace path retracing the stored locations of the forward path;
- and
- controlling the robot arm to return to the first position using determined return path.
A method of automatically determining a return path of a robot to avoid collisions while returning to a safe zone from an extended position outside of the safe zone, the method comprising:
- determining a distance between a current point on the return path, corresponding to a current position of the robot, and a next point on a retrace path previously stored in a location array during movement of the robot along a corresponding forward path from the safe zone;
- identifying the next retrace path point as a potential next point on the return path when the determined distance is greater than or equal to a grid size;
- calculating a ratio between the determined distance and a curve length of the retrace path between the current point on the return path and the potential next point on the retrace path;
- determining whether to reduce the grid size based on the calculated ratio;
- and
- when it is determined not to reduce the grid size, identifying the potential next point as an actual next point on the return path.
A computer readable medium storing a program, executable by a computer, for controlling an extendable robot arm to avoid collisions while returning to a safe zone from an extended position, the computer readable medium comprising:
- a return path determining code segment for determining at least a portion of a return path of the robot arm from the extended position to the safe zone based on previously stored locations of the robot arm as the robot arm moved along a forward path from the safe zone to the extended position;
- a waypoint determining code segment for determining a clear location and a retract location on the return path with respect to the extended position;
- a clearance code segment for determining whether the robot arm is clear of a station that includes the extended position at the retract location;
- and
- a radial pull-in code segment for determining whether a collision will likely occur during a blind radial pull-in of the robot arm along a radial pull-in path from the retract location to the safe zone, when the clearance code segment determines that the robot arm is clear of the station,
- wherein the blind radial pull-in of the robot arm along the radial pull-in path is performed when the radial pull-in code segment determines that a collision is not likely to occur, and wherein the robot arm moves to another previously stored location on the forward path when the radial pull-in code segment determines that a collision is likely to occur.
Dependencies are inferred from the claim text.