UVMS Controller Design Based on Double Close-loop Integral Sliding Mode

A double closed-loop integral sliding mode UVMS(Underwater Vehicle-Manipulator System) controller that can effectively overcome the uncertainty of dynamic parameters and current disturbance and significantly improve sliding mode chattering is designed. In actual marine operations, due to the complex underwater environment, it is difficult for UVMS to establish an accurate dynamic model and there are time-varying current disturbances outside it, which makes it difficult to control the motion of UVMS. Aiming at these problems, a double closed-loop integral sliding mode controller which is easy to apply in engineering and has good dynamic performance is designed. This controller can reduce the sliding mode chatter by designing the integral sliding surface instead of the traditional sliding surface and using the continuous hyperbolic tangent function instead of the discontinuous switching function. Moreover, it is not sensitive to hydrodynamic parameter changes and current disturbances and has strong robustness. Furthermore, the double closed-loop sliding mode structure makes the controller have faster convengence speed and better stability. At the same time, it does not need to identify parameters online, so it is also easy to implement physically. Finally, The simulation experiments of the UVMS are conducted to verify the feasibility and effectiveness of the controller.