Research On Exterior Trajectory Measurement And Correction

This paper begins with a profound analysis of the measurement of exterior trajectory and correction techniques,taking a hollow base cartridge as experiment platform, magnetoresistance sensor and Micro-electromechanical Systems(MEMS) accelerometer are utilized to measure muzzle velocity and axis acceleration. The main research works are as follows.On the analysis of magneto-resistance effect, a method to measure muzzle velocity based on magnetorsistive sensor is proposed. Firstly, the sinusoidal voltage waveform of sensor output is shaped and filtered to square waveform; secondly, the projectile's turns can be exactly obtained by calculating the optimum square wave. Finally, muzzle velocity is deduced from the relation between speed and axial acceleration of the projectile.In order to eliminate centrifugal acceleration of the accelerometers,a dual-accelerometer configuration is adopted to detect centroid axis acceleration of the projectile.Two accelerometers begin to sample acceleration when the round is flying off the muzzle,and microprocessor on the projectile calculates real-time axis acceleration.In order to meet requirements of a hollow base cartridge, a prototype measurement device based on TMS320F2811 was developed. Several critical issues, such as anti-high overload, low power consumption, high accuracy and determining the right time of flying off the muzzle, are solved. Signal processing circuit for magnetoresistance sensor and MEMS accelerometer, A/D circuit, data storage circuit, communication interface circuit and DSP control circuit are designed. Moreover, software modules are developed for controlling hardware circuits and realizing measurement algorithm of trajectory parameter.Ground test and firing range test both verified that trajectory parameter measurement based on magnetoresistance sensor and MEMS accelerometer is feasible,accurate measurement data can be obtained.Moreever, the measurement device feature anti-high overload capability and good anti-jamming performance,it can fully meet requirement of correcting fuze to the trajectory parameter measurement. At present,this technology has succeeded uses in the trajectory measurement and correction system servers in the army, which get high praise from the users.