The Development Of Directional Acoustic Receiver Using Multi-tube Array

This thesis studied the design technology of directional acoustic enhancement system based on multi-channel arrays. The thesis'work mainly contains hardware platform designing and enhancement algorithm design for the multi-channel arrays directional acoustic enhancement system. The work for hardware platform include: structure design of multi-channel arrays for miniaturized and portable model, dual DSP real-time signal processing system design for acoustic signal's mass data real-time processing and some other control unit design for application. The work for enhancement algorithm design include:real-time phase compensation for multi-channel signals, a special adaptive beamforming algorithm design for the system to accomplish directional acoustic enhancement.The project can be divided into four parts:Part1, the composition and principle of the directional acoustic enhancement system is described. We also briefly introduced other methods and presented our project's content and meaning by compared to these methods.Part 2, we mainly described the structure design of multi-channel arrays, we aim to design a valid structure to overcome the problem of oversize in single dimension exited in other methods. In this chapter we detailed our work for that target, include multi-channel acoustic signal simulation by using acoustic simulation software, calibrating method for rectifying real structure's phase shift and how our novel structure work well in this system.Part 3, we focused on the directional acoustic enhancement algorithm design for multi-channel arrays. In this chapter we also presented the principle of General Sidelobe Canceller (GSC) and how it works in this system to enhance the acoustic signal from target direction. In addition, the delay estimate methods, phase compensation methods and the adaptive enhancement algorithm designed for the system are also described in detail.Part 4, we mainly described the function design of the system, and briefly described the circuit hardware design as well.