Research On The Key Technology Of Active Vibration Isolation System Based On Ethernet Communication

The vibration of the diesel engine during operation will not only affect the safety of the hull itself,but also affect the normal operation of adjacent equipment.In addition,the noise generated by the vibration also seriously affected the crew's physical and mental health.For the warships,the vibration and noise will serious impact their concealment and fighting capability.Therefore,it is very important to control the vibration generated by the diesel engine.The traditional passive control means is difficult to isolate low-frequency vibration,and cannot adapt to the changing status of the equipment environment,so it can't effectively control the vibration.The active control technology can output the corresponding frequency anti-vibration force by certain control algorithm according to the real-time vibration condition,has good inhibition effect on low frequency vibration,which is the hot topic in the field of vibration control.Based on a double layer vibration isolation platform,a research into the adaptive active vibration isolation technology is carried out.The FxLMS algorithm based on secondary channel off-line identification is used as the active control algorithm to study the factors that will influence the control effect of the algorithm,and the simulation analysis is carried out.At the same time,in order to observe the control effect of the algorithm,the real-time monitoring of vibration is needed.The C# language is used to develop a PC software that can receive and display the real-time vibration information in Visual Studio platform,meanwhile the reliable communication between PC software and lower computer is been built.The main contents of this paper are as follows:1)The Ethernet is used to communicate the PC software with the lower computer,and a reliable transfer protocol based on UDP protocol is designed to achieve the real-time and reliable data transmission between the PC software and the lower computer.2)According to demands of the active vibration isolation system the PC software is designed.3)The function of the PC software was debugged and debugging results show that the upper computer system can receive and display the vibration signal and identification data collected by the lower computer in real time and reliably.In addition,the PC software also has the function of modifying the lower computer's data,meets the needs of active vibration isolation experimental stage.4)The adaptive control algorithm of the active vibration isolation system is studied,and the LMS algorithm is used as the identification algorithm of the secondary channel estimation model,the FxLMS algorithm is used as the adaptive active control algorithm.And the simulation experiment in Simulink was carried out,and the simulation experiment results show that the active FxLMS algorithm based on secondary channel off-line identification has good control effect,furthermore,increase the order of control filter and the iterative step size in a certain range can improve the convergence rate of the control algorithm and the control effect.