Active Vibration Isolation System Using Negative Stiffness

(1)高性能隔振系统零功率磁悬浮的非线性补偿采用零功率磁悬浮的隔振系统存在的问题之一是当扰动力作用于隔振表时，负刚度幅值偏离标称值。为克服这一问题，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)利用负刚度的气动三轴主动隔振系统研制了一种采用气动执行器产生负刚度的三轴主动隔振系统。推导了一种由作动器实现负刚度悬架的控制方法。实验证明，正、负刚度幅值的均衡化使系统对直接扰动的顺应性为零。(3)自重支撑机构的介绍对采用零功率磁悬浮的隔振系统进行了改进，增加了自重支撑机构。该机构可以减小零功率磁悬浮所承受的静载荷力。实验研究表明，即使增加了重量支撑机构，改进后的系统也能在直接扰动下保持无限刚度。(4)零功率磁悬浮加重量支撑机构的六轴隔振系统研制了零功率控制与被动重量支撑机构相结合的六轴隔振系统。采用非线性补偿，扩大了系统的工作范围。通过多次实验对控制器的性能进行了评价。

(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.