Design And Realization Of Receiver And Acquisition System For Fish-finder

As the requirement of fishery resources is increasing, the requirements of fishing equipment are also rising. Fish-finding sonar is very important for fish. It can accurately find the position of the fish and can fish efficiently. As the technology has developed, Fish-finding sonar is changing from single-beam to multi-beam. Compared with the single-beam fish-finding sonar, the multi-beam sonar has higher detection accuracy and detection range.This paper is based on the market, and depends on the multi-beam fish finding sonar, the paper completes the receiver and acquisition system for fish-finder and paving the way for fish-finding sonar equipment.Firstly, this paper states the development condition of fish-finding sonar at domestic and foreign markets, and analyzes the theory of the single-beam fish-finding sonar and the multi-beam fish-finding sonar. According to the functional requirements of multi-beam fish-finding sonar, we put forward the assignment of the paper.Secondly, depending on the system requirements, we put forward feasible formation of the system and present the scheme of the receiving system. The theory of phased array receiving is a guide in the design of receiving system to distinguish the source of signal beam.Specific design is made in the part of receiver, containing controllable gain amplifier circuit,filter circuit and a voltage follower. Selecting the appropriate chip and circuit form and correspond with the receiving system parameters to ensure its low noise and consistency character.Thirdly, we make designs for the hardware circuit of the acquisition system, including the daughter card of the FPGA, and the digital plate, including A/D analog-to-digital conversion circuit and D/A digital-to-analog conversion circuit. Based on the circuit schematic diagram I complete the design of PCB for the FPGA daughter card and the digital plate.Then, the paper introduces the SOPC technology and the NIOS kernel. Based on the hard circuit and the SOPC technology, the hardware and the software of the system are constructed. The function modules of the system are custom designed, and the SOPC system platform is built and the function of the system is verified by the debugging function of the NIOSII software.Lastly, the receiver and acquisition system is verified by the experiment, to prove the availability of it.