Active Vibration Isolation System Using Negative Stiffness

(1)零功率磁悬浮高性能隔振系统的非线性补偿零功率磁悬浮隔振系统存在的问题之一是在隔振平台上施加干扰力时，负刚度幅值偏离标称值。针对这一问题，将非线性反馈控制应用于零功率磁悬浮系统。实验证明了该方法的有效性。(2)气动负刚度三轴主动隔振系统的研制开发了一种具有气动负刚度作动器的三轴主动隔振系统。推导了一种利用该作动器实现负刚度悬架的控制方法。实验证明，正刚度和负刚度幅值的均衡使系统对直接干扰具有零柔度。(3)介绍了一个重量支撑机构振动隔离系统使用零功率磁悬浮进行了修改，以配备一个重量支撑机构。该机构可以减小零功率磁悬浮必须支撑的静载荷力。实验研究表明，即使增加这样的重量支撑机构，修改后的系统保持无穷大的刚度，以抵抗直接干扰。(4)采用零功率磁悬浮与重量支撑机构的六轴隔振系统开发了一种六轴隔振系统，该系统采用零功率控制与被动重量支撑机构相结合。采用非线性补偿技术，拓宽了系统的工作范围.控制器的性能进行了评估，通过进行几个实验。

(1) Nonlinear Compensation of Zero Power Magnetic Suspension for High-Performance Vibration Isolation SystemsOne of the problems of the vibration isolation system using zero-power magnetic suspension is that the amplitude of negative stiffness varies from the nominal value when disturabance force is applied to the isolation table. A nonlinear feedback control was applied to zero-power magnetic suspension to overcome this problem. The carried out experiment demonstrated the efficacy of this method.(2) Development of a Pneumatic Three-axis Vibration Isolation System Using Negative StiffnessA three-axis active vibration isolation system with pneumatic actuators for generating negative stiffness was developed. A control method of realizing a suspension with negative stiffness by the actuator was derived. It was demonstrated experimentally that the equalization of the amplitude of negative and positive stiffness enables the system to have zero compliance to direct disturbance.(3) Introduction of a Weight Support MechanismVibration isolation system using zero-power magnetic suspension was modified to be equipped with a weight support mechanism. The mechanism can reduce the static load force that the zero-power magnetic suspension has to support. Experimental study demonstrates that the modified system maintains infinite stiffness against direct disturbance even if such a weight support mechanism is added.(4) Six-Axis Vibration Isolation System Using Zero-Power Magnetic Suspension with a Weight Support MechanismA six-axis vibration isolation system was developed which uses zero-power control in combination with a passive weight support mechanism. The nonlinear compensation was also applied to widen the operation range. The performance of the controller was evaluated by conducting several experiments.