Channel Consistency Measurement System For Underwater Acoustic Equipments

This dissertation is based on a line array with tri-dimensional vector hydrophones,which can realize the underwater detection of multiple targets.Based on the channel consistency measurement of the vector array project,a channel consistency measurement system for underwater acoustic equipment is designed and implemented.The design can automatically generate frequency sweep test signal to measure the consistency of every channel.In addition,the design also has a data storage and transmission function.At first,the paper analyzes the design requirements of the system,from signal processing capacity,processing capacity,development difficulty,development workload etc.,and provides the basis for system design.On the foundation of this,a design scheme of channel consistency measurement system for underwater acoustic equipment is proposed.Using FPGA+ARM architecture,with the attendance of digital-analog conversion chip and analog-digital conversion chip,FPGA is responsible for test signal generation,signal sampling,channel consistency calculation and data transmission;ARM is responsible for instruction parsing,data storing,network uploading.FPGA and ARM can communicatie with each other through the ARM parallel bus.The selection of the core devices and the main indexs are given.The design and realization of the hardware circuit are completed in this paper.It is divided into four parts: peripheral circuit,FPGA module circuit,ARM module circuit and power module circuit.The design idea and function of each part are expounded in detail.Based on the hardware platform,the design and debugging of the software includes the design of the FPGA logic and the preparation of ARM software.Using modular design ideas,FPGA logic development uses CORDIC idea to achieve the rational use of logic resources to complete the sampling control module,signal generation module,consistency calculation module and ARM bus communication module.The communication between FPGA and ARM is realized by mapping the RAM in FPGA to ARM memory.Based on this,the program of ARM application layer and driver layer is written,and the test results of hardware and software are explained.The test results validate the expected functions and indexes of the design.