Research On The Synchronous Control Method Of Dual Hydraulic Cylinders Considering The Measurement Noise

The rocket launcher driven synchronously by two hydraulic cylinder servo system is a highly nonlinear system.Its nonlinear characteristics are mainly reflected in the nonlinearity of the rocket launcher's mechanism(the nonlinear function relationship between the displacement of the rod of the hydraulic cylinder and the pitch angle of the rocket launcher),the nonlinear pressure-flow characteristics of valve and so on.In addition,the tracking accuracy of synchronous control of servo system is also influenced by the measurement noise.The high-performance synchronous control methods are carried out to shorten the time of turning rocket launcher.The aforementioned problems will be taken into consideration in this dissertation,the main work is as follows:First of all,according to the technical requirements,the preliminary design of the main parameters of the rocket launcher hydraulic servo system and the selection of components are completed.The nonlinear mathematical model of the rocket launcher driven by dual-cylinder system is established,which takes into account the main nonlinear characteristics and model uncertainties of the actual system and describes the physical characteristics of the actual system more accurately.The above model plays an important role in designing the subsequent high-performance nonlinear controller.Secondly,the robust adaptive control strategy based on desired compensation and the robust adaptive control strategy based on low-frequency learning are proposed for nonlinear system with measurement noise.For the former,the actual output signal is replaced by the desired signal so that parameter adaptation will depend less on the measured value of the sensor,meanwhile,nonlinear robust term is used to deal with the residual error and uncertainty nonlinear.the latter integrates parameter adaptation with a new low-frequency learning,to achieve the aim of attenuating measurement noise in the position servo system of the dual-rod hydraulic cylinder.Experimental verifications of the proposed control algorithm(robust adaptive control method based on low-frequency learning)is presented by using a double-rod hydraulic cylinder position servo experiment platform.Thirdly,two control strategies based on the nonlinear mathematical model of the rocket launcher driven by dual-cylinder system are designed to achieves high performance synchronous tracking error.Compared with high-order sliding mode control strategy,the cross-coupling method of robust adaptive control method based on low-frequency learning introduces the concept of synchronous coupling error into the design of controller with the consideration of measurement noise,and the designed controller is proved rigorously by using Lypunov theory.The co-simulation results of AMESim and Simulink show that the validity of the proposed control method.