Patent ID: 6489741
Filing Date: 2002-12-03
Classification: B25J,G05B

Abstract:
In a robot having two or more degrees of freedom and a robot arm motivated by one or more motors and adapted to transport an object bidirectionally between approach and pickup positions, a method for transporting the object comprising:supporting the object at an initial approach position using the robot arm; determining the position of the motors corresponding to the initial approach position; determining the generalized coordinates of the robot corresponding to the initial approach position based on the determined position of the motors corresponding to the initial approach position; supporting the object at a desired pickup position using the robot arm; determining the position of the motors corresponding to the desired pickup position; determining the generalized coordinates of the robot corresponding to the desired pickup position based on the determined position of the motors corresponding to the desired pickup position; and moving the object between the initial approach position to the pickup position, wherein the object has an object axis and wherein the step of moving comprises synchronizing planar and elevational motions of the object such that the object travels between the desired approach position and the pickup position along a path at least partially coincident with the object axis, wherein the step of synchronizing comprises: developing, during a learning mode, one or more motion control algorithms for guiding the robot arm along associated predetermined trajectories which comprise one or more radial trajectories, non-radial multi-segment trajectories, or non-radial trajectories with compound velocity profiles, said developing comprising analytically calculating planar and elevational velocity profiles for predetermined object and robot geometry, stiffness and weight; and using the one or more control algorithms to guide the motion of the robot arm between the desired approach and pickup positions.