Research On The Application Of MEMS Vector Hydrophone In Obstacle Avoidance Sonar

With the development trend of large-scale high-speed and the massive increase in thenumber of ships, water traffic density has been increasing. Meanwhile, marine accidents haveoften happened under the inclement weather, etc. The assembly rate of traditional obstacleavoidance sonar system is quite low in civilian ships because of the larger volume and thehigher cost. Accordingly, a smaller size, lower cost obstacle avoidance sonar system hasbecome a pressing need.T-type MEMS vector hydrophone is a kind of small size, high sensitivity and low costunderwater acoustic sensor combining the MEMS technology and underwater acousticsdesign. The obstacle avoidance sonar systems were designed based on T-type hydrophone. Inthe beginning, this paper introduces the working principle of T-type hydrophone, focusing on thetest of hydrophone performance. In the following part, the paper ascertains the design schemeand operating parameters by analysis of the sonar equation combining of hydrophoneperformance. With T-type hydrophone sonar system as a receiving end, the system utilizesactive pulse ranging method to achieve obstacle avoidance functionality through SCM.System design mainly includes structural design, hardware and software design.Transmitter in the system structure is designed to horn shape with continuously changingcross-sectional area, expecting to gather energy effect and then to improve sound emittingenergy. Considering the practical application of obstacle avoidance systems on different ships,this paper develops to design a small transmitting device fixed on hull through stronglymagnetic adsorption. The hardware module includes transmitter circuit, receiving andprocessing circuit, and signal conditioning circuit. Besides, the receiving and processing circuit canconvert echo signal to the level signal which SCM is able to recognize. SCM can implement the transmitter, receiver, proximity real-time display and warning function of acousticsignals over program control.System prototypes tests are respectively performed in the anechoic pool, reservoir andmarine environment, including static tests and dynamic tests. After repeated tests, it turns outthat the sonar system is able to accurately measure the distance and realize obstacleavoidance capabilities. In such a way, I hope this paper will further promote the engineeringapplications of MEMS vector hydrophone.