Patent ID: 6317651
Filing Date: 2001-11-13
Classification: B25J,G05B

Abstract:
A trajectory generation system to operate a robotic manipulator in response to a motion command, where the manipulator includes an end effector, having a position and an orientation, and a plurality of joints, each joint having a position, velocity and acceleration, the generation system comprising:a Cartesian trajectory generator operable to convert the motion command into a requested Cartesian positions vector and a requested Cartesian velocities vector;a Jacobian matrix of the manipulator defining the relationship between a manipulator joint velocities vector and a manipulator Cartesian velocities vector;an inverse of the Jacobian matrix for transforming the requested Cartesian velocities vector to a requested joint velocities vector;an inverse kinematics determiner operable to calculate a requested joint positions vector based upon the requested Cartesian positions vector, wherein the requested joint velocities vector and the requested joint positions vector define a planned vector of the manipulator; anda singularity handler activable in response to detecting a singularity, to constrain the motion of the robot manipulator through the singularity such that the joint velocity of each joint of the manipulator does not exceed a predetermined maximum velocity, wherein the singularity handler comprises a null space mover to perform a move in a null space of the Jacobian matrix, such that the aligned joints are moved to appropriate destination values and the position and orientation of the end-effector are not affected.