Research On Robust Control For Submersible In The Presence Of Disturbances

Submersibles are indispensable strategic equipment for marine exploration,international competition,and can boost national strength.The submersible is also the result of crossover of multiple fields.China has outstanding achievements in the field of submersible research,such as Qianlong 1,Qianlong 2 and Jiaolong.As the using areas of submersible increases,increasingly complex engineering tasks continue challenging the control performance of submersible.Therefore,the design of high-performance robust control algorithms for submersible is important in the overall design of submersible systems.Based on the analysis of the research results of the trajectory tracking control algorithm of the submersible at home and abroad,this paper chooses a class of over-actuated submersibles as the research object,and extracts the problems that need to be paid attention to or avoided in the design of the tracking control algorithm.The external disturbance is dealt with by a robust controller,and a control distribution algorithm is proposed to solve the over-actuated problem of the submersible.The main research contents are as follows:1.According to the six degree-of-freedom operating characteristics of the submersible,established inertial coordinate system and body coordinate system respectively,and established the relationship between the two coordinate system by Euler transformation.At the same time,considering the disturbance and parameter uncertainty,the submersible Kinematic-dynamic equation under complex environment is constructed.2.Aiming at the lumped disturbances composed of parameter uncertainties and external disturbances in the system,an expanded state observer is designed to estimate the lumped disturbances.A full-order non-singular terminal siliding mode controller is further designed,and it realizes the tracking control of the submersible on the preset trajectory under the disturbance.3.Further analyze the disturbance in the submersible system.Disturbances in system can be divided into beneficial and harmful items,and effectively use the information of beneficial disturbance.The controller is designed by Lyapunov function to compensate harmful disturbances and further improve the trajectory tracking performance of the submersible.4.Aiming at the over-actuated characteristics of submersibles and considering the problem of energy optimization,a control distribution algorithm is designed based on quadratic programming,and the energy calculation method of actuators and the cumulative calculation method of control system errors are given.Finally,the simulation results verified the effectiveness of the control allocation algorithm designed in this paper.