Control of Industrial Robot Joint Flexibility Using Acceleration Feedback

Many industrial robotic arms are used for general pick and place operations. These particular robotic arms are usually driven by timing belts, which limit the speed of the pick and place operation due to undesirable vibration at the end of the motion. This undesirable vibration is attributed to the timing belt’s flexibility, which introduces resonance inside the servo bandwidth. The objective of this paper is to demonstrate a simple and robust approach, which can be easily implemented in real time, to control robot belt flexibility. By using standard industrial accelerometers and a sliding observer, all the information required to implement a control can be estimated. A description of the sliding observer design and the vibration suppression controller are presented in this paper. Simulation results show how this technique can successfully reduce the robot end-point vibration and improve the bandwidth of the servo controller.Copyright © 2005 by ASME

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