Design Of Ranging Sonar System Based On MEMS Bionic Vector Hydrophone

With the development of marine enterprise, the available range of sonar is extendedincreasingly. We increasingly depended on sonar in civil field such as echo sounding，propagation navigation and ship dynamic positioning, as well as in military field. The ship is avery important water transportation mean, which has a long history and play a vital role ineconomic and social development. In recent years, with the increasing of ship and trafficdensity, and the ship’s large-scale and high-speed, shipwrecks including stranding, collisionand grounding often occur in foggy weather. So the water transport efficiency and trafficsafety problems become serious increasingly. To this end, this paper designed and developed akind of obstacle avoidance system based on MEMS vector hydrophone, which has theadvantages of efficiency and economy.This paper researches the design and integration of ranging sonar system. The workmainly includes: The design of ranging system transmitting terminal, receiving end, fixingdevice of receiver-transmitter, and the relevant software and hardware; the research ofanti-flow technology for receiving hydrophone; the research of accurate alarm technology ofthe system. Firstly, by comparing and analyzing the advantages and disadvantages and theapplicable scope of various active ranging sonar methods, the paper selects the pulse rangingmethod as the ranging method. Comprehensively considering various influence factors, suchas blind zone, range resolution, transmitting source level, sound transmission loss, the activesonar signal parameters are determined, and then the directional transmission transducer isselected and the transmitter drive circuit is also designed; secondly, according to the activesignal frequency, we optimized structure of the double T-type MEMS bionic vectorhydrophone. Meanwhile, to reduce the flow noise, the hydrophone dome is designed, the anti-flow noise ability of which is tested; thirdly, the signal processing circuit is designedaccording to the echo signal characteristics; fourthly, we design the resilient shock absorbingsuspension for the device of receiver-transmitter to prevent false alarm; finally, softwareprograms including location algorithm procedures and alarm procedures are designed.Ranging sonar designed in this paper adopts active working mode. SCM (Single ChipMicrocomputer) control circuit is the core component of the system, which control the systemoperation. SCU transmits10kHz square wave pulse, the signal drives the piezoelectricceramic transducer through the power amplification to convert electrical signals into acousticsignals then transmits the directional acoustic to water. Subsequently the acoustic reflected byan obstacle is received by the double T-shape MEMS vector hydrophone, and then the signalis input into SCU after conditioning circuit. Ultimately the acoustic target distance isreally-time showed by LCD, after algorithms processing.The tests of the avoidance sonar for the static and moving targets are finished in anechoicpool and reservoir. The experimental results show that the ranging sonar system has goodranging function and high ranging accuracy, realizing the dynamic measurement of movingtargets. Moreover, the system can realize the critical distance alarm, and the more anxious thealarm is， the more closer the obstacle distance is. The avoidance sonar system has broadapplication prospects.This paper firstly realized the application for the MEMS bionic vector hydrophone asobstacle avoidance sonar receiver, and laid a certain foundation for realizing the goal ofomni-directional detection by hydrophone array. Expect that the research in this paper maycontribute to the orientation research of MEMS bionic vector hydrophone in the ocean,further realizing its engineering application.