Optimal input shaper design for high-speed robotic workcells

This paper deals with the feedforward control of a high-speed robotic workcell used by the NIST-A TP Precision Optoelectronics Assembly Consortium as a coarse stage to achieve micrometer-level placement accuracy. To maximize the speed of response under different load conditions, robust feedforward algorithms are considered. An optimal shaper is synthesized to trade off performance and robustness according to assembly specifications of the workcell. The optimal shaper along with standard shaper designs such as zero vibration, zero vibration and derivative, and extra insensitive are applied to conduct cycle time testing on the robotic workcell. The performance of each shaper is evaluated with respect to residual vibration, robustness, and speed. Specifically, the workcell performance for various unknown loading conditions is observed. It is shown that the optimal shaper produces the best overall results.