Investigation Of Active Vibration Isolation System With Integrated Sensor-actuator On A Flexible Base

In this paper, an inertial actuator and its controller of an active vibration isolation systemwere designed, simulated and test. Then the dynamic characteristics of a single stage vibrationisolation system equipped on a flexible base were analyzed. Eventually, active controlsimulation and experiments were conducted on the system to investigated the controlperformances.Above all, the dynamic characteristics of the inertial actuator were studied, and the resultshowed that the amplitude of output force was related to the magnetic strength of the air-gapand the stiffness of support springs. Thus, ANSOFT was used to investigate the influence onmagnetic strength of an air-gap while the structure optimization module of ANSYS wasemployed to optimize the parameters of the supporting leaf springs. Based on the optimizedparameters, the inertial actuator model was produced and tested. Then, a MEMSaccelerometer was designed and embeded within the actuator. Secondly, the subsidiarycontroller of the actuator was designed with a matched amplifier. More exactly, to deriveproper circuit parameters, the integral, phase shift, and filter circuits of the controller weresimulated using Multisim8. Then the controller hardware was maded and tested. Furthermore,a developed Fourier series expansion method and Finite Element method were employed toinvestigate the dynamic behaviors which involved the modal characteristics as well as thevibration transmission of the vibration isolation system on a flexible base. To confirm theaccuracy of analytical results, a laser vibrometer was used to obtain the vibration modes andresponse of the system. In the end, experiments were conducted to examine the controlperformance of the integrative actuator and controller on the flexible single stage vibrationisolation system. The results indicate:1. Acceleration feedback control can effectivelyattenuate the vibration amplitude up to10dB in certain frequency ranges;2. Velocity feedbackcontrol can only reduce the resonance amplitudes by4dB;3. The control performance ofmulti-point control is worse than single actuator control in certain point whereas multi-pointcontrol is better considering the whole control performance. In conclusion, the feasibility ofthe designed actuator, controller and accelerometer, and the feasibility of the control strategieswere verified.