Optimizing Design And Self-Adaptive Control For Electro-Hydraulic Servo Control Unit Of Ship Rudder

As a direction-navigating equipment, rudder is indispensable for every ship. Electro-hydraulic servo control unit, which is the research object of this paper is the key control component for rudder systems. By adjusting the swash plate of the variable delivery piston pump, the purpose of controlling the system flowrate could be satisfied. Its characteristic has a direct influence on the performance of the whole rudder system. With the development of marine technology and national defense industry, ship rudders are demanded to pose higher performance index than ever before. Therefore, the research of electro-hydraulic servo control unit is significant from both theoretical and practical point of view.In the previous studies, Central oscillation, asymmetry of left and right movement and insufficient precise and speed of response are the main problems of electro-hydraulic servo control unit. Based on great amount of domestic and broad references and considering practical problems, control strategy is chosen in this paper.By analyzing every component's working principle, electro-hydraulic servo control unit is modeled in this paper. Moreover, the reasons of central oscillation and error and asymmetry of left and right movements is given special attention. Using Matlab6.5 as a simulation tool, the radical clearance is adjusted in order to optimize the system. After optimization, time domain response of various typical signals and the frequency domain response are simulated. In order to make left and right movement symmetry, improve precision and rapidity of response, the model-reference self-adaptive-controller is designed by the method of error polynomial algebra ,which is based on the steady theory of LIAPUNOVE A.M. Its validity is tested by simulation with various typical signals and the adaptive velocity is analyzed. With all those works done, the adaptive controller's performance is tested by simulation with the new parameters of changed temperature.Based on theoretical analysis, great amount of research work are done on simulation. The results of simulations show that stability of the system could be significantly improved by adjusting the radical clearance between the valve piston and sheath. At the same time, the results also show that model reference adaptive controller could expand the band width, symmetrizes the left and right movement and improves precision and rapidity of response. even with the temperature fluctuation, the demand of performance could be well guaranteed.