基于准零刚度隔振器的自适应模糊控制

Quasi-zero stiffness(QZS)isolator has both high bearing capacity and low natural frequency, and has a good effect on isolating ground vibration. However, the stiffness of the QZS isolator is low at the balance position, which makes the load highly sensitive to the direct disturbing force of low frequency, and the working position of the isolator is easy to deviate. Secondly, the greater the disturbance of the load of the QZS isolator, the stronger the nonlincarity. This nonlinearity will lead to amplitude amplification and amplitude jump. To solve the above problems, an adaptive fuzzy control method based on nonlinear QZS isolator is proposed. This method adds position feedback on the basis of sky-hook, takes the vibration frequency of the load as the adaptive coefficient, and establishes the relationship between the adaptive coefficient and the vibration frequency with the sigmoid function. Firstly, the physical model of the QZS isolator is established, and then the system dynamic characteristics and control system are simulated by Matlab / Simulink. Finally, an active vibration isolation test system is built to verify the effectiveness of the proposed method. The results show that the proposed method has a good inhibitory effect on the complex and time-varying direct disturbance acting on the load, and can accurately locate the load.