ENERGY EFFICIENT TRAJECTORY DESIGN FOR THE UNDERWATER VEHICLE WITH BOUNDED INPUTS USING THE GLOBAL OPTIMAL SLIDING-MODE CONTROL

In this paper, we propose a novel global sliding mode controller (SMC) for an uncertain linear time-varying second order system. The proposed controller was implemented on the underwater vehicle (UV) with uncertainty of bounded parameters and disturbances within limited control input. By applying the proposed controller to the second-order UV system, the arrival time at the reference position and the maximum allowable acceleration are expressed in a closed-form equation if ranges of parametric uncertainties and reference inputs are specified. The closed-form equation can be utilized in designing the capacity of vehicle systems with the condition of the minimum arrival time to the target position. The superior performance of the proposed control scheme is validated through computer simulation. The simulation results show that this proposed controller forces the UV to track the designed time optimal trajectory very well, even with uncertainties. Its robustness can be guaranteed if bounds of the uncertainties are known.