Research On Missile Attitude Measurement And Positioning Technology Based On Position Sensitive Detector And GPS/SINS

Laser semi-active guided projectile has become a research hotspot in recent years due to its precise strike capability.Accurate acquisition of the position and attitude of the projectile is an important prerequisite for the realization of accurate attack.In this paper,the attitude determination and positioning of projectile based on position-sensitive detector and GPS/SINS is studied.GPS/SINS integrated navigation is used to obtain the position and attitude of projectile,and position-sensitive detector is used to calculate the attitude of the sight angel the projectile,thus realizing accurate measurement of the position and attitude of the projectile.(1)In order to ensure the normal operation of GPS receiving module of GPS/SINS integrated navigation system,based on the characteristics of laser semi-active guidance weapon platform,an active GPS navigation antenna including four-arm spiral antenna,feed network and low noise amplification circuit is designed.The field test results of the antenna show that the carrier-to-noise ratio of the processed soft-plate conformal antenna and the manual patch antenna are both high,and the satellite search and positioning can be realized well for the flying attitude of the projectile in all positions.(2)In order to adapt to the war environment with strong electromagnetic interference within the limited flight time of projectiles,an improved algorithm based on Extreme Learning Machine(ELM)is proposed to predict the position and attitude of the projectile in the GPS/SINS integrated navigation system when the GPS fails.The algorithm predicts the navigation information of the projectile through ELM,and finally realizes the optimal estimation of the position and velocity information of the projectile.The simulation results show that the algorithm can well predict the position and attitude of the projectile in the GPS failure state.(3)In order to obtain accurate spot position of position sensitive detector under pulse excitation,the spot position extraction and compensation method is studied.Based on the characteristics of laser echo power received by strapdown laser semi-active seeker,a spot position extraction system with high dynamic and narrow pulse width is designed.The spot position response model of the position sensitive detector is established.To verify the model,spot position extraction experiments under near-field pulse light are carried out.According to the phenomenon of spot position shrinking in the experimental results,the error of spot position is analyzed.The results show that error correction is needed for the detection system of position sensitive detector and its signal processing circuit.Based on this,a low-cost correction method for spot position under pulsed light is proposed.Experiments show that when the correction coefficient is 1/0.434?1/0.507,80% of the point error can be controlled within ±0.15 mm.An experiment was carried out to extract the line-of-sight deviation angle of projectiles and targets under the excitation of far-field pulses.The experimental results show that for the reflected laser at 990 m,the position-sensitive detector can realize the detection of a maximum field angle of 12°.