Research On AC Servo System Identification And Control Strategy For A Certain Shipborne Rocket Launcher

A strong navy is needed to build our country into a powerful marine nation,which used to protect the safety of coastal area.Compared with the missile weapon system,the rocket gun weapon system has huge efficiency compared to cost,and it is easy to use and safeguard.With the development of the international situation and modern military techniques,the higher requirements are advanced for the firing accuracy,striking density and fast response ability of shipborne rocket gun weapon system in modern war.AC position servo system is one of the key technologies of high precision weapon system,which is used in automatic aiming of the elevation angle and azimuth angle of rocket launcher.In order to solve the high performance position aiming problem in the strong uncertainty and serious nonlinearity condition,this dissertation took the development of a certain shipborne rocket launcher(SRL)as the background and mainly studied the modeling methods and control strategies of AC position servo system.Therefore,there are important theoretical significance and project application value to further study the topic research,for enhancing the comprehensive performance of our national SRL AC position servo system.The majority work in the dissertation were summarized below:(1)Aiming at mathematical modeling and uncertainty compensation of SRL AC position servo system,under establishing the PMSM equivalent model with the vector control method,a mechanism model of the servo system was constructed which including the current-loop,speed-loop and position-loop.The main inside and outside factors which caused its the nonlinearity and time-varying were discussed.The influence of ship swaying on the the tracking firing accuracy of rocket launcher was analyzed and the principle compensation was made.(2)Aiming at the problem of establishing accurate mechanism model for SRL AC position servo system,a DEPSO-WNN identification method was proposed.The pseudo random multiamplitude signal was selected as the reference input.Through the semi-physical simulation,the sample data for system identification was obtained.The proposed identification method was verified.Based on the system model reversible internal model control method,an improved wavelet neural network-internal model controller(WNN-IMC)was studied.The effectiveness of the designeded controller was verified by the simulation experiments.(3)Aiming at suppressing the internal and external disturbance caused by the parameters perturbation and sea conditions in SRL AC position servo system,an improved active disturbance rejection controller based on improved fractional order PID controller(FOPIDIADRC)was designed.As the important components of the designed controller,the stability of Extended state observer and the FOPID controller were analyzed,respectively.Under the principle of off-line rough adjustment and real-time fine adjustment,the PSO algorithm was adopted to optimize the five parameters of FOPID controller.The simulation results verified that the designed controller has certain robustness and good dynamic performace.(4)Aiming at improving the robustness and tracking accuracy of SRL AC position servo system under complex nonlinear and strong uncertainty conditions,the RBF-NADRC-PBC controller and the IPSO-BP-ADRC-PBC controller were proposed,respectively.The RBFNADRC-PBC controller designed the passive controller based on torque observation for its inner speed loop,and proposed the improved neuron ADRC controller for its outer position loop.The IPSO-BP-ADRC-PBC controller designed the passive controller based on the IDAPBC for its inner current loop,and proposed the second order ADRC controller for its outer position loop.The intelligent algorithms based on neural network were adopted to optimzied some parameters of the two designed conttrollers,respectively.The simulation results verified that the two designed controllers had high robustness and excellent static-dynamic characteristic.Compared with the improved WNN-IMC controller,the FOPID-IADRC controller and the RBF-NADRC-PBC controller,the IPSO-BP-ADRC-PBC controller had the highest tracking accuracy and the strongest robustness.(5)Aiming at the semi-physical simulation test of SRL AC position servo system,its software and hardware were done,and its semi-physical test platform was built.Then,the investigation of the semi-physical simulation tests with the FOPID-IADRC and IPSO-BPADRC-PBC controller were done.The testing results showed that the two controllers could meet the specified performance requirements,and the performance index of IPSO-BP-ADRCPBC controller was obviously better than the FOPID-IADRC controller.Under the conditions of no-load and full load,the IPSO-BP-ADRC-PBC extreme values of the adjustment time,the steady-state error and the equivalent sine tracking error were as follows 2.75 s,0.030 and0.083.When a specific load was suddenly applied,the maximum deviation was only 0.093,which just cost 0.63 s to recover the reference target.The effectiveness and feasibility of the designed IPSO-BP-ADRC-PBC controller were verified by the testing results.