Research on hydrodynamics analysis and double loop integral sliding mode control of 4-joint underwater manipulator

Abstract

Given the importance of underwater manipulator in the process of grasping and carrying the object, the simple 4-joint underwater manipulator is designed. Considering the factors of water flow, the hydrodynamic model is established by using the Morision formula. Through the numerical calculation method, the effects of the buoyancy, water resistance and added mass force on the dynamics of the underwater manipulator are analyzed. On this basis, the controllers of the conventional sliding mode algorithm and the double loop integral sliding mode algorithm are established. The simulation results of trajectory tracking show that: the double loop integral sliding mode algorithm has better performances in response speed, stability and adaptability compared with conventional sliding mode control algorithm. This paper provides valuable references for the dynamic study and motion control of underwater manipulator.