Distributed, real-time control of structurally flexible manipulators

Parallel processing facilitates the real-time implementation of an end-effector velocity controller for elastic robotic manipulators. The approach has potential application in teleoperation. We have developed an algorithm that controls end-effector velocity of large robotic manipulators whose size-to-weight ratio renders them structurally flexible. The controller takes: desired end-effector velocity as input. It seeks to minimize the velocity tracking error in the end-effector by concentrating its effort on the end-effector while letting the manipulator's links deform. The control strategy relies on a feedforward-feedback concept, designed around an augmented model of the manipulator dynamics, which includes derivatives of the control input in addition to integrator states that minimize tracking error. We implemented the algorithm for parallel processing on a multiprocessor system. The controller's performance agrees well with computer simulations.<
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