The Research And Design For The Hardware Of The High Frequency 2D Imaging Sonar

Conventional Sonar is mainly used to detect the distance and orientation of the long-distance target, which is often regarded as a point. So the receiving array adopts a line array that can only distinguish the targets in one plane such as horizon or vertical. As the development of the underwater intelligent robot, the task of the detecting system is more and more difficult, So the needing of the detection and identifying becomes more important. The Acoustic 2D Imaging Sonar can obtain the 2D images by the receiving sound signals.While the target is still,the sonar can restructure the target 3D images from the 2D images. So the underwater intelligent robot can identify and classify the detected target.In this paper, the hardware system of the underwater receiving unit of the Acoustic 2D Imaging Sonar is researched and implemented. Because the sonar system have high frequency, high resolving capability and 128 receiving channels, the unit can not only sampling , store and translate the receiving sound-signals, but also have the property of lower power. In addition to increase the stability and the repair capacity, the system adopts the design idea of modularization. The main works are as follows:1. The design of analog signals processing module. The designed of analog signals conditioning subsystem can filter interference and noise of the receiving signal, and then acquire useful information. So the output signal can meet the need of the voltage level needed by the ADC. The phase consistency can reach the demand by the reasonable design. Designing the system power module power the whole sonar system.2. The design of digital signals processing module. The sampling and storing subsystem can convert the analog signal to digital signal, and then store the sampling data into the fifo.The digital signals processingsubsystem preprocess the data stored in the fifo.3. The design of system controlling module . After the system controlling module received the command from the surface unit , the controlling subsystem control the digital signals processing module work respectively, then the system controlling module continue to process the result from the digital signals processing module.When the processing is over,the controlling subsystem will translate the last result to the surface unit through high-speed trandlating module 7B923.A11 this process are controlled by the controlling subsystem.4. Debugging the system in the laborary, The three experiments prove that the underwater receiving system works at steady state. It can satisfy the need of the system. The pool experiments prove that the sonar can identify the underwater objects.