Parallel dynamics computation and H∞ acceleration control of parallel manipulators for acceleration display

In this paper, we propose a control scheme of parallel manipulators focusing on the accuracy of acceleration on the end plate, an important factor when parallel manipulators are used as acceleration displays such as a driving simulator. In order to achieve a smooth and accurate acceleration on the end plate, we combine two controllers: A dynamic controller to achieve accuracy of the position and to stabilize the system, and an H-infinity controller to feedback the acceleration of the end plate to cope with the unmodeled dynamics such as mechanical flexibility and friction. The main problem of dynamic control is computational complexity. We applied parallel processing to reduce the latency and realized real-time dynamic control. The designed H-infinity controller is added outside the closed loop of dynamic control to remove the vibration of the structure and the influence of unmodeled dynamics.