Distributed Control for Coordinated Motion Tracking of Multiple PMAs Cluster

In this paper, a coordinated motion tracking control scheme is investigated for multiple pneumatic muscle actuators (PMAs), to implement the motion coordination for the PMAs cluster. System construction for the proposed coordinated tracking system is elaborated, including the single PMA and cluster system design, communication topology among PMAs, performance analysis of the cluster system. Based on a three-element model structure, the model parameters are identified by several groups of real-time experimental tests, and the mathematical model of PMA applied to a specific pressure range is obtained, which can be used in the design of control algorithm. Through the PID tuning of each PMA and the design of distributed coordination controller of the cluster, the motion positions of PMAs are coordinated. Experimental results demonstrate that the distributed coordinated controller with necessary information interactions between each PMA modeling by proposed experimental identification method is valid for the motion tracking of the PMAs cluster.