Cooperative Strategy for Hydraulic Synchronous Lifting Systems with Industrial Applications

The cooperative control problem of hydraulic synchronous lifting system consisting of multiple cylinders is studied in this paper. The hydraulic cylinders are assumed to be equipped with wireless data transfer units and can exchange information with their neighboring cylinders. Based on the leader-follower structure, a distributed control protocol is designed for each follower to track the states of the leader utilizing information of local neighbors. Furthermore, adaptive control method is adopted to estimate the upper bound of the leaders unknown control input and external disturbances. Sufficient conditions are derived to guarantee the tracking errors converge to zero by Lyapunov stability theory. Finally, numerical simulations are carried out to illustrate the effectiveness of the theoretical results.