Millimeter Wave Interferometer Signal Research Within The Bore

With the further development of internal ballistics theory, the Precision technology puts forward higher requests, and the measurement accuracy demands for athletic parameter within the projectile bore become higher and higher. In the test of athletic parameter within the projectile bore, because of the smoke, dust, electromagnetic and other interference on the test system, the projectile echo signal acquired often is accompanied by serious problems like signal distortion or noise interference. Therefore, the precise measurement of projectile motion speed is the key of the projectile motion parameters testing. Based on this application background, it is important to propose the analysis and research for signal in the bore of millimeter-wave interferometer.This dissertation is based on the principle of speed on the basis of research objectives,solving the projectile velocity by using the maximum method. According to the Doppler principle, It need to calculate the instantaneous signal frequency when measuring projectile velocity. The extreme point carries the Doppler signal instantaneous frequency information,so it is essential to identify the position of the extreme points for accurately estimating the frequency of the projectile echo signal. A method for quadratic curve fitting is proposed to deal with the noise of echo signal, and it can find out all the extreme value points according to the principle of quadratic function, as well as eliminating invalid extreme points accurately produced by the piecewise fitting method. Through the actual signal verification, it improves accuracy for determining the position of extreme value point and lays the foundation for high precision measurement of moving targets.The dissertation on the basis of the extremum method, proposes a prediction algorithm based on Kalman filter. Through the establishment of a mathematical model for projectile velocity, it produces the optimal prediction for solving the projectile velocity information,further improving the measurement accuracy of the projectile velocity. Validated by the measured signal analysis, the finally measured value of the projectile velocity is more close to the real value, and the error is smaller. The speed measuring precision meet the requirements of the project: better than 0.3%. It proves that the method really has practical application value.