Design Of Projectile Coordinate Measuring Device Based On Ultrasonic Wave

Vertical target density is one of the important indexes of evaluating weapon accuracy performance. Based on passive acoustic positioning principle, the thesis has mainly focuses on devices for measuring projectile coordinate, which is based on ultrasonic sensors. Meanwhile, it also contains theoretical analysis and experimental research of the measurement error of the device.Through to analysis of the measured wave waveform and N theory, identified the rise of the shock wave can be used as at some point along the shock waves reach the moment of feature points. Through the simulation analysis respectively to compare the three arrays within 10 m*10 m test target surface location accuracy, the thesis has determined their scope. Meanwhile, it has laid foundations for choosing corresponding system.The thesis has analyzed the causes of accuracy of acoustic vertical target coordinate measurement error according to the process of generation and transmission of shock wave signal. According to the shock wave propagation characteristics, the thesis, in the case of 12.7 mm bullet, studied shock wave speed transmission attenuation rule. What’s more, it has the simulation analysis of the apparent velocity attenuation in the positioning error. The thesis extracts the feature points to produce error according to threshold value method. Meanwhile, it has tested the signal conditioning circuit of the synchronization performance and also analyzed effects of channel phase difference on the positioning accuracy. In addition, there are analyzes of the sensor connecting pieces of processing and installation error influence on positioning accuracy. Also there are analysis of the shock wave and sensor of distance of sensor signals.The projectile coordinate measuring experiment device is designed. Based on NU40C10T/R-1 type piezoelectric ultrasonic sensors, the front two triodes and operational amplifier circuit to achieve the level of ultrasonic sensor output signal of amplifier, based on LM339 shaping circuit and trigger circuit is designed. Based on the Cyclone I EP1C3T144C8N FPGA design time calculation module, the function time delay calculation is realized. Introduced the FIFO module implements the function of quick save slow hair, the repeating test is implemented. Based on MSP430F149 MCU control module is designed. Based on Lab VIEW. Write the PC software to realize the function of the projectile coordinate measuring display and data report.The experiment mainly uses type 56 sub-machine gun,7.62 mm projectiles in target passage for ball firing experiments. Within silhouette paper effective testing, the positioning precision of the maximum error is 1.6 cm.