基于多边形膜片弹簧与压电致动器复合的一体化主被动Stewart减振系统

随着遥感卫星光学成像设备等精度的不断提升，其对振动环境的要求也在不断提高，简单的线性被动Stewart平台已经无法满足苛刻使用要求。提出了一种新型基于多边形膜片弹簧与压电致动器复合的一体化主被动Stewart减振平台，其单自由度元件主要由多边形膜片弹簧、压电致动器、力传感器以及柔性铰链组成。相较于传统线性隔振器存在的高静刚度和低动刚度之间的固有结构矛盾，所提出的多边形膜片弹簧作为隔振器的关键原件，兼具高静-低动（HSLD）特性，能够使隔振系统同时具备较高的静态刚度进行静态承载以及较低的动刚度进行动态减振。为了降低被动隔振系统中存在的共振峰幅值，本文在被动膜片弹簧元件的基础上串联一个压电致动器与力传感器组成的主动控制元件进行主动振动控制。仿真结果表明，采用比例积分力（PIF）反馈控制算法的主动控制系统，在频域上不仅可以通过积分力环节搭建出天棚阻尼的效果来降低共振峰峰值（11.19 dB），而且其比例-力环节可等效为增大了质量矩阵项，能够有效降低减振系统的固有频率（20.9 Hz），拓宽其减振带宽，并同时能维持高频段的高衰减性，在时域上也能够将系统的加速度振动幅值从±0.6g降低至±0.07g，振动衰减达88%。

Integrated active and passive Stewart vibration damping system based on polygonal diaphragm spring and piezoelectric actuator

Continuous improvement in the accuracy of remote sensing satellite optical imaging equipment places increasingly higher demands on the vibration environment, and the simple linear passive Stewart platform can no longer satisfy the stringent requirements. A new integrated active and passive Stewart vibration damping platform based on the combination of the polygonal diaphragm spring and the piezoelectric actuator is presented. The single leg of this platform is mainly composed of a polygonal diaphragm spring, a piezoelectric actuator, a force sensor and two flexure hinges. To resolve the inherent contradiction between the high static stiffness and the low dynamic stiffness in the traditional linear vibration isolator, this paper proposes a polygonal diaphragm spring, the key component of the vibration isolator, with High-Static-Low-Dynamic (HSLD) characteristics. It enables high static stiffness for static loading and low dynamic stiffness for dynamic vibration reduction of the vibration isolation system. To reduce the amplitude of the resonance peak in the passive vibration isolation system, we connect an active control element consisting of a piezoelectric actuator and a force sensor in series on the basis of the passive diaphragm spring element to control the active vibration. The simulation results show that the active control system using the PIF feedback control algorithm can reduce the peak value of resonance (11.9 dB) by building the effect of ceiling damping through the integral force link in frequency domain, as well as increase the mass matrix term, effectively reducing the natural frequency (20.9 Hz) of the damping system and broadening its damping effect. Meanwhile, it can maintain the high attenuation of the high frequency band, and reduce, in the time domain, the acceleration vibration amplitude of the system from ±0.6 g to ±0.07 g, with the vibration attenuation reaching 88%.