Research On Trajectory Tracking Control Method Of The Offshore Wind Power Tower Pile Detection Robot

With the proposal of constructing the Maritime Silk Road which serves as the national policy,the development of offshore wind power generation,nuclear power generation etc.has gradually developed into a emerging strategic industry in China,and the requirements for the detection and maintenance of related equipment is increasing day by day.Because of the special environment of offshore wind power equipment,there are great hidden dangers existing in the traditional method of manual detection.Thus,it is urgent to develop a comprehensive system with detecting robots which are suitable for offshore wind power tower pile.In order to ensure the quality and efficiency of the detection operation,an appropriate control method is needed to solve the interference and error of the system.With the appropriate control method,the offshore wind tower pile detection robot can move accurately according to the given trajectory.In this paper,a trajectory tracking control strategy based on slip error suppression and slip error compensation is proposed for the "skid" phenomenon in the trajectory tracking process of offshore wind tower pile detection robot.It provides a reference for the autonomous and intelligent development of offshore wind tower pile detection robot.The basic theory of trajectory tracking control of offshore wind tower pile detection robot is deduced.In this paper,the kinematics and dynamics model of the tower pile detection robot is established by using the characteristics of incomplete constraint system.The adjustment range of adsorption magnetic force of tower pile detection robot is solved by simulation software,and the simulation results are verified according to the experimental data of magnetic force test.The friction mechanism of the driving wheel of the tower pile detection robot in underwater environment is studied.The simulation results of sliding friction coefficient under different rotational speed and adsorption force are compared,and the main factors affecting sliding friction are analyzed.The trajectory tracking control strategy of tower pile detection robot considering sliding friction is proposed.The calculation method of slip rate and slip rate of the driving wheel of the tower pile detection robot is derived,and the research on slip suppression and slip recognition of the tower pile detection robot is carried out.The adaptive trajectory tracking controller is designed by using the position and pose error model of the tower pile detection robot.The simulation results show that the control strategy is feasible and effective in solving the slip and slip error of tower pile detection robot.The model predictive control method is used to solve the actuator saturation constraint caused by the trajectory tracking control strategy proposed in this paper.Combined with the kinematics and dynamics model of the tower pile detection robot,a double closed loop trajectory tracking control system based on nonlinear model prediction is designed,and the recursive feasibility and stability of the system are proved.The event trigger mechanism is used to improve the algorithm of solving the optimization problem in model prediction,which saves the calculation cost in model prediction control.The simulation results show that the improved algorithm based on event trigger can improve the real-time performance of the system.The control system of tower pile detection robot is designed,and the track tracking experiment of tower pile detection robot is carried out.The construction of the onshore and underwater control subsystem and underwater detection simulation environment,and completing the actuator saturation constraint condition test and trajectory tracking experiment of the tower pile detection robot,verify the effectiveness and advanced nature of the trajectory tracking control strategy proposed in this paper.