Navigation And Roll Atttidude Determination Technology By Non-omnidirectional Antenna Under Rotation Condition

Precision attacking ammunition is an important development direction of weapon equipment.Course correction fuze technology is a key approach to realize the precision attack of classical unguided ammunition. An approach of navigation, positioning and rolling attitude detection method based on GNSS information received by non-omnidirectional antenna is studied for two-dimension course correction technology. The work focus on the development of the rolling attitude detection using the amplitude modulation information provided by non-omnidirectional antenna with rotation, as well as the research on signal tracking, navigation and positioning under the phase interference of rotating Doppler induced by signal amplitude fluctuation during the rotation process of non-omnidirectional antenna.The related research work are as follows:(1) Signal modulation characteristics analysis with rotation of non-omnidirectional antenna. Due to the non-symmetry of non-omnidirectional antenna radiation direction gain figure, amplitude, frequency and phase of the received signal vary with the non-omnidirectional antenna rotation. By radiation performance analysis, impact analysis is developed on amplitude, frequency, and phase as well as carrier noise ratio of the received signal from non-omnidirectional antenna. The theory basis are provided to solve the navigation, positioning and rolling attitude detection problem using the GNSS information received by non-omnidirectional antenna.(2) GNSS navigation tracking method of non-omnidirectional antenna under rotation condition. In the light of the problem of signal lose lock and difficult position for conventional receiver, an adaptive Vector Delay/Frequency Locked Loop(VDFLL) tracking baseband signal processing method is proposed.By impact analysis of the conventional receiver baseband signal processing with rotation non-omnidirectional antenna, the requirements on the performance of navigation and tracking algorithm is put forward in this special environment. An adaptive vector tracking model is established and the observation equations are linearized. According to the received signal characteristics of rotation non-omnidirectional antenna, an estimation model of carrier to noise ratio is established, the mechanism and process of vector tracking filter are analyzed, vector tracking algorithm of carrier phase and control model of pseudo code NCO are given.Through the experiment, the correctness of the proposed adaptive vector tracking algorithm,signal detection under short-time occlusion, weak and dynamic condition and performance advantages are verified.(3) Study on the rolling attitude detection method based on the satellite signal.Using the periodic variation characteristics of the received signal amplitude during the rotating process of non-omnidirectional antenna, a rolling attitude detection method based on the principle of phase locked tracking is put forward. Satellite position vector relationship model is established, the roll angle transformation model respect to the fire coordinateis given. The navigation receiver with function of rolling attitude detection is proposed.Through optimize chosen of the DC bias integrator parameters of roll of demodulation loop, impact of the loop filter by the predetection integration time is researched, by performance analysis and design of the loop filter, rolling attitude detection error is analyzed.(4) Two element micro-strip array antenna is chosen as the signal receiving unit, the navigation positioning and tracking method with function of rolling attitude detection proposed in this paperis verified by experiments. Results show that, Navigation tracking method with function of rolling attitude detection method proposed not only avoid the adverse effects of the received signal tracking caused by non-omnidirectional antenna rotation,but also perform a good performanceon roll attitude detection and weak signal tracking. Semi-physical simulation experiments show that, with rotation of non-omnidirectional antenna, the accuracy of position detection is 5m, mean square error of the detected rolling phase is less than 5deg.The turntable experiment shows that, the case of available satellites number is as less as four, positioning erroro adaptive vector tracking algorithm is less than 15 m and the input signal is tracked continuously.