Study On Coupled Vibration Characteristics Of Rudder Electro-hydraulic Servo Regulator And Vibration Control

Along with the development of shipbuilding, ship the growing tendency of large, high-speed, steering the movement controlled by electro-hydraulic servo control regulator, so the regulator required stability, reliability and easy to control. REG260 type of electro-hydraulic servo steering regulator system is a typical electro-hydraulic servo system, servo valve open-shut moves, oil within the system have been rapid alternating movements of the pressure wave process is water hammer, flowed in the transmission line, it cought be cause the larger vibration amplitude in piston area, deviate the mandate direction of the rudder, the ship sailed to the security threat. Hydraulic water hammer phenomenon is the unsteady flow; flow parameters vary is the dynamic changes in the transition process. In particular, it is interaction between valve spool, valve sleeve of electro-hydraulic servo system regulator, the system of water hammer effects more complicated in the pipeline network. It is necessary to research the servo system of water-induced vibration mechanism and the characteristics and the law related to the influence of factors deeply, in order to take appropriate control measures to reduce or suppress the vibration of water hammer, to protect the safety of the system operation.First, the electro-hydraulic servo steering Regulator REG260 for static and dynamic characteristics were analyzed for symmetric asymmetric cylinder valve control theory, redefines the load flow and pressure, and consider the existence of symmetric zero valve clearance and leaked to establish a system of model. Simulations show that the system is stable and has good step response and tracking performance.Then, account structure coupled with the oil, the vibrate source -- the servo valve coupled vibration of water hammer is studied, whereas viscosity of hydraulic system is the larger transient flow model, the proposed model is a complete servo valve coupled differential equations of motion of water hammer. Use the method of characteristics derived characteristics of vibration force of the water hammer; laid the study foundation of pipeline transmission characteristics and control; In numerical calculation using Lagrangian grid handling moving boundary conditions. Frequency - domain analysis shows that neglected the impact of moving boundary condition, the error will be great with the boundary changes; Since moving boundary conditions, for junction coupling, when the servo valve opened quickly, pipeline water hammer effect obviously, on the contrary, servo valve opened slowly, pipeline to axial vibration frequency vibration stress wave dominated, the bigger frequency composition of water hammer vibration increases. There is still a larger vibration amplitud after servo valve open-shut moves; Servo valve open-shut law of the water hammer effects were more marked, under the system vibration coupling water hammer equation, using of nonlinear programming algorithm, by the study of water hammer process, the optimal curve law coupling water hammer calculation wree derived, the optimization law of water hammer pressure decay rate of approximately 7dB. From a practical application, for the optimization using the law includes a two-stage and three-stage linear, the rate of pressure decline is 18.2% and using adaptive neuro-fuzzy logic control, and achieved good results.According to water hammer vibration response calculation results of the analysis, vibration controls of REG260 the servo system wree proposed from two aspects of the adjustment of system impedance and reduce the vibration source. The results show that the adjustment of the length of pipe from the frequency domain analysis may avoid resonant frequency of pipe, it is simple and effective method to improve the management of long to 0.73 m, pressure vibration attenuation rate should be 6dB; Load impedance of the piston area and the capacity cavity length of the initial parameters to be improved, application of nonlinear programming method for the optimization of system impedance, the optimization of the structure parameters, adjusted the system impedance, effectively reduced the amplitude of water hammer pressure, the pressure vibration attenuation approximate rate of up to 6 dB.Finally, adoption of REG260 electro-hydraulic servo steering regulator experiments, studied its static and dynamic characteristics and the water hammar coupling vibration characteristics, the experiments showed that the use of symmetric asymmetric cylinder valve control theory established by the mathematical model can be effective for system stability discrimination, and relationship of input drift the output displacement signal analysis; consider oil and structure coupling model, through the pressure oscillation experiment of the servo valve port and calculation results deviation is 2.87%; and the hydraulic cylinder with a rear-chamber pressure trend consistent with the calculation results, verified coupling vibration model is correctness; the use of servo valve open-shut law two stages of testing rear-chamber pressure is 13.04% decline, proved the control measures is effectiveness.