Research And Design Of Active And Passive Vibration Isolation System Based On Permanent Magnet Electromagnetic Composite

According to the vibration isolation requirements of a certain type of equipment,a new permanent magnet electromagnetic composite active and passive vibration isolation system based on negative stiffness theory is designed,the vibration isolation system model is established,the fuzzy PID active control strategy is adopted,and the rationality of the vibration isolation system design is verified by simulation.Finally,an experimental platform is built to verify the vibration isolation effect of the designed system.The main research contents of the paper are as follows:1.On the basis of putting forward the indexes and performance of the vibration isolation system,a new structure vibration isolation system is designed by combining the mechanical spring and the permanent magnet electromagnetic hybrid actuator.The mechanical spring is used as a passive vibration isolation device,and the material of the spring is reasonably selected and the geometric size and physical characteristics of the spring are designed.As an active vibration isolation device,permanent magnet electromagnetic hybrid actuator includes electromagnet part and permanent magnet part.Firstly,the shape,size,iron core and armature material,coil turns,wire diameter and working air gap of electromagnet are analyzed and designed.The second is the design of permanent magnet.At the same time,the negative stiffness characteristics of permanent magnet are considered to balance the positive stiffness caused by mechanical spring and the spatial assembly structure of permanent magnet.The finite element model of permanent magnet electromagnetic hybrid actuator is established by using Ansoft software to obtain the suction and negative stiffness characteristics of permanent magnet under different thickness,so as to determine the length,width and thickness of permanent magnet.2.The model of permanent magnet electromagnetic composite active passive vibration isolation system is established,and the system is analyzed and simplified.From the perspective of electromagnetism and dynamics,the equivalent magnetic circuit diagram of the system is obtained,and the electromagnetism equation and dynamics equation of the system are established.The complex nonlinear model of the system is simplified to a linear model by linearization.Finally,the current loop is designed to reduce the order of the system.3.The active control strategy based on Fuzzy PID is designed.Simulation results show that the control strategy is feasible for vibration isolation system.The equivalent stiffness and damping of the system can be obtained by substituting the fuzzy PID algorithm into the system model.The simple passive vibration isolation device,permanent magnet mechanical spring vibration isolation device and permanent magnet electromagnetic composite active and passive vibration isolation device using fuzzy PID control technology are simulated and compared.The results show that compared with the mechanical spring vibration isolation system and permanent magnet mechanical spring vibration isolation device,the active and passive vibration isolation system based on Fuzzy PID control and negative stiffness theory has better vibration isolation performance,and can meet the vibration isolation requirements and indexes of a certain type of equipment.4.A permanent magnet electromagnetic composite active and passive vibration isolation platform is built.The vibration isolation experiment is carried out through the built experimental platform.The experimental results show that it can meet the vibration isolation index of a certain type of equipment,has good vibration isolation effect,and verifies the feasibility of the system design scheme.