Water Fuze Ultrasound Probe Positioning Method And Echo Planar Loop Simulation System Design

Proxy positioning and target classification are the two primary functions for precise explosion controlled by fuze arming system.Target discrimination and arming timing is controlled by proxy positioning for underwater state of the art weapons, tactical missdistance to the target of intersection requires higher positioning precision. Therefore, to ensure damage within explosion radius, the underwater fuze demands better ultrasonic proxy device for precise positioning and target classification. In this paper, underwater acoustic fuze for proxy planar positioning of depth charge has been studied, which support development of high precision target detector for the novel fuze. By designing HIL system based on echo generator, development cycle and cost could be reduced.Planar positioning algorithm for underwater proxy and fast detection has been reviewed. By analyzing the principle of dual transducer positioning system, formula for calculating target position has been derived. Constrained by the hardware, GCC time delay estimation algorithm has been adopted to ensure positioning precision. Without major change of the structure of fuze and ultrasonic detector, topology structure of emit and receiving shared and switching piezoelectric transducer has been designed.Dual transducer positioning has been designed in FPGA platform, the algorithm has been realized by separate modules of FFT, power spectrum, PHAT, IFFT, modular arithmetic, peak detector and so on. Each module has been programmed HDL, verified by timing simulation. HDL top level calling file has been established to finally realize the dual transducer planar positioning for FPGA. Simulation result indicates that functionality and real-time ability of the system.To deal with the inconvenience of modifying waveform amplitude quantization value in ROM of the signal generator implemented by ROM based on DDS, the scheme of digital echo signal generator based on FPGA soft core DPRAM and USB was put forward. Hardware in the loop simulation system has been designed by modified8channels signal generator. Dual transducer positioning experiments have been performed and show that error for dual transducer positioning is insignificant.The method and result of the research provide boththeoretical and experimental foundationsfor studying positioning technology of underwater ultrasonic detector.