Study On Active Isolation System Based On Giant Magnetostrictive Actuator

The theory analysis and experiment research of active isolation system based on Giant Magnetostrictive Actuator (GMA) are discussed in this dissertation. The main purpose of the research is to improve the vibration controlling precision of vibration isolation platform by means of Giant Magnetostrictive Actuator as the active vibration control element.In the preface we begin with the engineering background of active isolation technology and GMA, of which the research, use and development are stated in detail, especially the control rule and AI material used in active isolation system, practical use and advantage of them.In chapter 2 design and principle of the precision active isolation platform are discussed. Design of GMA is discussed in detail and it consists of magnetostrictive phenomenon, basic characteristics of Terfenol-D, design of hollow AC electro-magnetism circuit, design of the Bias Magnetic Field and precompression spring.In chapter 3 model of active isolation system is constructed. Firstly, theoretical model of the isolation platform is constructed. Secondly, mathematical model of the GMA is inferred from constitutive equation and the temperature influence to the strain of Terfenol-D is considered. At last the whole measurement and control system is introduced in this dissertation. The software element and the hardware element are discussed in detail especially. Special emphasis is put on the design of the power amplifier and modularization design of the measurement and control system software.Chapter 4 mainly include active isolation experiment and simulation research. The use of PID control algorithm in active isolation system is discussed firstly. We identify the constructed model offline by means of PID modeling technology in the active isolation experiment, then the isolation result leading from different disturb frequency is reviewed. Secondly, numerical simulation is carried out according to the disturb signal of single frequency, double frequency and noise.The characteristics of GMA include static, frequency response, hysteresis and hysteresis model, dynamic step response is tested in chapter 5.At last main achievements of this dissertation are summarized and the further research work, which will be done in the near future is put forward.