Sliding mode synchronous control for fixture clamps system driven by hydraulic servo systems

Although the two sides clips of a fixture clamps system have the same driving mechanisms, the synchronous error between the dual drivers of the two clips is generated by non-balanced forces. With position variation of clips and various uncertainty disturbances during the working process, the synchronous movement of the two clips is difficult. In the current paper, sliding mode synchronous controller is designed for fixture clamps system which is driven by hydraulic servo system. Setting the load dynamic error of one driver as external disturbance to the other driver, the departure from synchronization caused by the parameter variation and external forces between two clips is limited. The stability of the control system and the convergence of synchronous tracking errors are guaranteed by Lyapunov stability theory. Simulations illustrate the applicability of the proposed approach.