Research On Model-free Adaptive Vector Control Strategy Of Ship Podded Propulsion Motor

Ocean shipping is with high energy consumption and emission, and its related energy resource conservation and pollution reduction are the key issues of national maritime industrial development. Researches on control problem of ship podded propulsion motor system are beneficial not only to propulsion motor scheduling and optimization, but also to energy-saving and emission reduction. Due to the fact that the podded propulsion motor is a nonlinear system with the large inertia, strongly coupling and variations of parameters which has the problem of measuring disturbance and load disturbance that caused by the including wind, wave and flow, the model-free adaptive vector control (MFAVC) strategy for such a system are studied in this dissertation.First, to overcome disadvantage of model perturbation that caused by the uncertain dynamic for the conventional marine podded propulsion motor vector control system, a control scheme combined model-free adaptive control with vector control is proposed. Furthermore, the dynamic linear equation of SSP propulsion motor is deduced, and an model-free adaptive vector control based on the speed tracking error is designed. The consistent and bounded of tracking error for the system are ensured by adjusting the PPD online. The theoretical analysis and simulation results show that the controller designed by the above scheme has nice robustness to the model perturbation and environmental disturbances.Second, according to the fact that only one step samping information of the past is utilzed by the model-free adaptive vector control method, the high-order model-free adaptive vector control (HO-MFAVC) is proposed based on the high-order learning law for the purpose of making full use of more ship sailing control information of prievious by designing a new control input criterion function, it makes the controller more flexible. The convergences of modified algorithms are given, and the activeness and superiority of the algorithms are verified by simulations.Third, the model-free adaptive vector control algorithm with deadband disturbance observer is designed for the problem of frequency operation of the controller which caused by the unknown external load disturbance that acting in the propulsion motor system. Firstly the control deadzone is introduced into the update algorithm of the MFAVC control law, secondly a disturbance estimator based on extended state observer is designed, lastly the convergences of modified algorithms are given, and the simulation results show that the improved algorithm not only can makes the unknown load diaturbance suppressed and avoids wear of the SSP propulsion motor gear actuator control system that caused by the requency operation of the controller, but also makes the ouput of the system more smoothly and improves the robustness of the control system performance.Forth, the active disturbance capability of the MFAVC algorlthm is researched for the measuring disturbances which are caused by the complex dynamic characteristic and rough working conditions, the model-free adaptive vector control based on the wavelet analysis is introduced. The observation information is pretreated by wavelet analysis, then the control law is constructed by this method. The convergences of modified algorithms are given, and the simulation results show that the improved algorithm has a good performance, strong robustness to the measuring disturbance.