Adaptive PD-SMC in position domain for contour tracking of hybrid actuated system

A hybrid actuated system is a special mechatronic system that combines two different driving motors: an uncontrollable constant velocity (CV) motor and a controllable servo motor. It is a challenge for controlling such a hybrid actuated system to achieve high contour tracking performances. Following the position domain control principle, the CV motor is viewed as a master motion and to define the corresponding motion of the servo motor for a desired contour tracking. In this paper, the adaptive PD sliding mode control (PD-SMC) is applied in position domain to force the servo motor following the motion of the CV motor for contour tracking control. Such a control method can achieve much better contour performances, because it can obtain the dynamics of the system through adaptive law and avoid the tracking error caused by the speed fluctuation of the CV motor, guaranteed by the position domain control methodology. Simulation study results for linear and nonlinear contours with/without initial errors are presented to demonstrate the advantages of the adaptive PD-SMC in position domain.