A Study On Coherent Demodulation And Adaptive Equalization Applied To UWA Communications

With the rapid development of electronic technology and the variety and intelligence of torpedo, researching a new and effective anti-torpedo method has been an important part of modern defensive industry. The mine-hunting sonar system is produced in such a condition, and it defines the torpedo's position by use of sound wave emit by the sonar array which is installed on the bottom of the ship.This paper discusses the PID and Sliding Mode Variable Structure (SMVS) Control of the sonar array attitude stabilization system respectively and designs the digital controllers. The simulation results have been compared. The system based on PID control theory has characteristics of fast response speed and higher peak overshoot, and it also has a good performance of tracking, but it is lack of ability of disturbance rejection. Because SMVS control method is insensitive to the variations of the model parameters, nonlinear and exterior noises, the attitude stabilization system designed based on SMVS has fast response speed, higher ability of disturbance rejection and has no peak overshoot, namely, the system is robust.At last, this paper realizes the sonar array attitude stabilization system based on the simulation circuitry and introduces the method of how to make control system with PC/104. The attitude stabilization system is debugged successfully..