Manipulator sliding mode control with disturbance observer under external vibrational loads

초록

Manipulators mounted on an unmanned ground vehicle should be operated very accurately with various missions such as bomb detection and disposal. The manipulator is sometimes situated in harsh outdoor conditions like wind, snow and shock blow occurring sinusoidal disturbance torques on the joint motors which are strong relation with manipulator link structure. In this study, sliding mode control (SMC) combined with disturbance observer based (DOB) and repetitive disturbance observer (RDO) were considered at addressing the tracking control issue for a simplified three-DOF robot manipulator. The manipulator dynamic equation was derived and Lyapunov stability is investigated to analyze the control stability and robustness of SMC and disturbance estimators. Several simulations were implemented, compared among traditional proportional, integral and differential (PID) control, SMC and combined SMC. It was verified that this combined SMC method was suitable for minimizing tracking errors and fast tracking