| In order to ensure the accuracy of the vehicle-mounted missile strike,it is necessary to measure the azimuth angle of the prism on the missile with a directional collimation measuring device before launching to determine the initial launch azimuth angle of the missile.At present,the directional collimation measurement equipment supporting the vehicle-mounted missile must be placed on an optical measurement platform with an independent base.The independent base is separated from the vehicle to prevent the measuring equipment from being affected by the vibration of the vehicle.The operation of the equipment is difficult and the operation time is long,which seriously affects the maneuverability of the equipment.With the development of equipment modernization,the directional collimation measurement equipment is subjected to vibration isolation treatment,so that it can get rid of the dependence on independent platforms,and realize stable measurement in the state of fixed connection with the vehicle,which will greatly improve the automation level of the equipment And rapid response capabilities.In view of the characteristics of vehicle vibration mainly concentrated in the low frequency range,this thesis selected the active vibration isolation scheme to conduct a research on the isolation of vehicle vibration.The main research work and results are as follows:1.The influence of vibration on the measurement stability of the gyroscope and the self-collimation measurement are analyzed.The dynamic model of the single-stage active vibration isolation system is established.The overall scheme of the active vibration isolation system of the vehicle-mounted measurement platform is determined.2.The empirical mode decomposition method is used to analyze the frequency spectrum characteristics of vehicle vibration.In the process of empirical mode decomposition,modal aliasing is produced.And modal aliasing has not been effectively suppressed by ensemble empirical mode decomposition.Aiming at the modal aliasing phenomenon of complex signals,this paper proposes a noise stretch ensemble empirical mode decomposition method,and uses the method to decompose vehicle vibration.The modal aliasing is effectively suppressed.3.The force transmission rate model of the single-stage active vibration isolation system is established through the equation of motion.The static and dynamic characteristics of the VT-300 electromagnetic actuator are researched through two methods: theoretical modeling and experimental modeling.A mathematical model of the relationship between the output signal of the electromagnetic actuator and the frequency and amplitude of the output signal is established.The simulation of active vibration isolation under fuzzy PID control is carried out according to the model.4.We design an embedded signal acquisition and processing circuit.The circuit uses TMS320VC33 as the processing chip,and integrated A/D,D/A,I2 C and other digital interface circuits in a high-density FPGA chip.Through direct memory access to data,data acquisition and data processing are carried out at the same time,which simplifies the circuit and improved the system integration.5.We make an active vibration isolation prototype and build a simulation experiment platform in the laboratory.Verification test is carried out.The experimental results show that the vibration transmitted to the output end of the actuator is reduced by 21.3d B.The orientation error of the north finder is 138?,and the measurement of the autocollimator is not affected by vibration.This thesis uses digital means to control vibration isolation,and provides technical support for the stable operation of the directional collimation measurement equipment when it is firmly connected to the vehicle.The photoelectric measurement equipment can ensure the measurement accuracy while getting rid of the dependence on the independent support platform.The application of active isolation vibration will play a positive role in improving the maneuverability of the equipment. |
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