| It is particularly important for the measurement system of light screen array to accurately extract time when the projectile crossing light screens.However,under the influence of the signal conditioning circuit,the dynamic performance of the output signal of the system is degraded,resulting in distortion of the output signal,and the deterioration of the signal consistency of each channel.As a result,the measurement error of the system increases.In this thesis,the dynamic compensation model of the light screen array is constructed by using the nonlinear autoregressive models with exogeneous inputs(NARX)neural network,and the dynamic characteristics of the system response before and after the compensation are analyzed through simulation.The results show that the method can significantly improve the dynamic characteristics of the response of light screen array.The main research contents and conclusions of the thesis are as follows:1)Based on the measurement principle of the light screen array,a semi-physical simulation calibration platform for the multi-dimensional measurement parameters of the light screen array is designed.According to the mathematical measurement model of the light screen array,the generation formula of the analogue signal of the calibration platform is deduced,and the calibration principle is clarified.The calibration platform was built by using general instruments,and the effectiveness and accuracy of the calibration method was demonstrated by comparing it with the traditional live-fire calibration method.Based on the calibration platform,the quasi-δ pulse calibration of the light screen array was carried out,and the dynamic performance of the light screen array was initially analysed,and data support and compensation results verification methods were provided for subsequent research.2)Through simulation analysis,the application scenarios of various least squares methods in system identification are investigated and the performance of the algorithms is quantified.The generalised least squares method with whitening filter applicable to the light screen array is determined and a differential model of the light screen array is established to provide an accurate analysis of the dynamic characteristics of the system and provide a reference for the subsequent compensation link effect verification.3)The principle of dynamic compensation is expounded,and the compensation model of the light screen array is established by using the NARX neural network algorithm,the dynamic characteristics of the system response after compensation are simulated and analyzed,and the dynamic performance,multi-channel consistency and measurement result error,the results show that the method can significantly improve the dynamic performance and measurement accuracy of the light screen array.This thesis focuses on improving the dynamic characteristics of the light screen array,and establishes the compensation model of the light screen array,which is of great significance for improving the measurement accuracy of the light screen array. |
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