Design and application of a sliding mode controller for accurate motion synchronization of dual servo systems

• A sliding mode controller for motion synchronization of dual servo systems is developed.
• The controller couples dual servo drives for accurate motion synchronization.
• Implementation in an industrial double-sided milling process shows effectiveness of the controller.

This paper presents a continuous time sliding mode controller (SMC) design to deal with the problem of motion synchronization in dual spindle servo systems. Synchronization error is defined as the differential position error between the two servo drives that follow identical reference motion trajectory. Proposed SMC controller penalizes three error states; namely individual axis tracking errors and the synchronization error for accurate synchronization. The control law is derived from Lyapunov energy function without switching condition. The controller shows robust motion synchronization against disturbances and parameter variations. Proposed SMC control is implemented in conventional double-sided machining operation.