Contour control for direct drive X-Y table based on a new exponential reaching law

This paper investigates the contour control problem of an X-Y table driven by two permanent magnet linear motors based on terminal sliding mode control method. By introducing a non-singular terminal sliding mode control(NTSMC), a novel contour controller is designed for biaxial motion control system. A variable exponential reaching law based on equivalent error was designed in order to eliminate the influences of parameter variations, external disturbance and friction force on contour accuracy. To guarantee the actual contour trajectory converges to desired trajectory in finite time, L1 norm of equivalent error state variables was introduced to the exponential reaching law. Finally, we validate our results experimentally using an X-Y table.