Background: It is easy to carry out a wide range of high-precision micro movement on the
magnetic levitation stage which also turns to be suitable in precision manufacturing and ultra-precision
measurement field. In view of the strong coupling and nonlinear characteristics of the dynamic model of the
sandwich layer structure, the differential geometry soft variable structure control method is proposed.
Method: Based on differential geometry theory, the study of state feedback linearization for dynamic
model of the magnetic levitation movement stage is conducted, which implements the exact
linearization and decoupling in the vertical and horizontal subsystems of the stage. The soft variable
structure controller with variable saturation is designed according to the linear model of the subsystem.
Result: The simulation results show that the control method is able to achieve better performance than
the PID and sliding mode controller and satisfy the requirement of precision positioning.