Integrated Design of Machine Body and Control Algorithm for Improving the Robustness of a Closed-Chain Five-Bar Machine

An integrated design approach, namely, design for control (DFC), is further studied in this paper. Previous work on the DFC approach usually takes the proportional-derivative (PD) control algorithm. It is revealed in a closed-chain five-bar machine case that the PD-based DFC approach can only obtain a desired performance in set-point control task rather than tracking control task. In order to improve the robustness of this mechatronic system in terms of change of tasks, this paper suggests to use a "PD plus robust term" control algorithm in the DFC approach. Theoretical analysis shows that a satisfactory performance can be achieved by the proposed DFC. And it is also shown that the gain in the robust term plays an important role in bridging design of control algorithm and design of machine body. The general design principle of machine body is to design parameters of machine body to minimize the lower bound of this robust gain. Finally, the effectiveness of the proposed approach is validated by simulations.