Global fast terminal sliding mode control for direct drive XY table by permanent magnet linear synchronous motor

Considering nonlinear and uncertainty of the system and complex contour error model, in order to improve contour machining precision, a global fast terminal sliding mode control based on equivalent errors method was proposed. Nonlinear equivalent errors model of direct drive XY table by permanent magnet linear synchronous motor(PMLSM), which is easily calculated, was built by using equivalent errors method. Direct drive XY table contour controller was designed by global fast terminal sliding mode method. The method can make the states of the system converge fast to the equilibrium point in finite time and reduce the affect of load disturbance and uncertainty of the system. The simulation results show that the designed contour controller can make the system of direct drive XY table have high contour machining precision and strong robustness.