| Nowadays the dual triangle horizontal acoustic positioning system has been used in coordinate positioning of the impact point,but its positioning precision still cannot meet the increasingly high test requirements.Based on the principle of dual triangle passive acoustic positioning,this paper attempts to systematically analyze the error factors in the positioning process of the dual triangle horizontal acoustic positioning system,and make theoretical analysis and experimental study,in order to lay a foundation for the design of high precision acoustic positioning devices.The system studies the error source in the positioning process of the dual triangle horizontal acoustic positioning system and its error characteristics.And the influence of mathematical model and nutation angle of projectile on positioning precision is discussed.The influence of wind speed and direction on positioning precision is simulated and analyzed.Then the positioning error which is introduced by projectile incidence angle(azimuth and pitch angle)is simulated and analyzed,and the maximum incidence angle in the range allowed by positioning precision can be determined.Additionally,the influence of the velocity attenuation of shockwave signal on the positioning precision of the system is simulated and analyzed.The effects of sensor,signal conditioning circuit and feature points extraction judgment on positioning precision are discussed and the validation test is designed to determine the error range.The paper designs error source experimental verification platform and sets up the experimental test system.Electret-type acoustic sensor is selected as the shockwave signal measurement sensor,and the corresponding signal conditioning circuits are designed to realize the filtering,amplifying and shaping of the sensor output signal.Based on FPGA and MSP430,time difference data extraction module,storage module and communication module are designed to realize the collection,calculation,storage and remote wireless transmission of shockwave signal.Besides,based on Lab View,the real-time control and display interface of the host computer are designed.The experiment studies the consistency of shockwave signal measurement sensor and the influence of relevant parameters of filter circuit,amplifier circuit and shaping circuit on the positioning precision by using the error source experimental analysis platform.In the paper,the debugging method of the dual triangle horizontal acoustic positioning system is studied and the corresponding debugging device is designed.The high-frequency acoustic generator is designed to analyze the characteristics of sensor and system circuits.The analog coordinate signal generator is designed to simulate the six-way time signal when the shockwave approaches,which is used to analyze and test the performance of the system except the sensor.The control method of verticality of the trajectory and the virtual test target surface is studied and the corresponding control devices are designed to reduce the influence of the positioning error caused by the incorrect installation of the test target.The wind speed,incidence angle,and shockwave attenuation experiments are designed to verify the correctness of simulation analysis. |
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