基于相对位移反馈的主被动复合隔振控制器设计

Design of Passive-Active Composite Vibration Isolation Controller Based on Relative Displacement Feedback

摘要:

针对超精密加工与测量仪器的振动隔离需求，提出主被动复合隔振平台设计方法。为扩展隔振频带并改善全频段隔振性能，在被动隔振基础上，整合平台与环境端的惯性速率传感器、相对位移传感器及隔振促动器，构建主被动复合隔振系统，研发基于相对位移反馈的主动复合隔振控制器。该控制器通过配置隔振系统动态刚度与阻尼，解决被动隔振固有频率附近振动放大的难题，结合环境振动速度前馈回路进一步优化性能。试验结果表明，所提方法使振动速度均方根值下降 13.5 倍，低频段（<2Hz）、中频段（2Hz-5Hz）和高频段（5Hz-100Hz）的振动功率谱分别衰减至被动隔振下的 19.6%、1.2% 和 6%，有效满足超精密仪器对振动隔离的严苛要求。

Abstract:

To meet the vibration isolation requirements of ultra-precision machining and measuring instruments, a design method for an active-passive composite vibration isolation platform is proposed. To expand the vibration isolation frequency band and improve the full-band isolation performance, an active-passive composite vibration isolation system is constructed by integrating inertial rate sensors, relative displacement sensors, and vibration isolation actuators on the platform and environmental side based on passive vibration isolation. A novel active composite vibration isolation controller based on relative displacement feedback is developed. This controller configures the dynamic stiffness and damping of the vibration isolation system to solve the problem of vibration amplification near the natural frequency of passive vibration isolation, and further optimizes the performance by combining with the environmental vibration velocity feedforward loop. Experimental results show that the proposed method reduces the root mean square value of vibration velocity by 13.5 times, and the vibration power spectra in the low-frequency band (<2Hz), medium-frequency band (2Hz-5Hz), and high-frequency band (5Hz-100Hz) are attenuated to 19.6%, 1.2%, and 6% of those under passive vibration isolation, respectively, effectively meeting the strict requirements of ultra-precision instruments for vibration isolation.