周期性机械振动主动控制算法

为提高周期性机械装置的隔振性能,减少其对底座(或地面)及周围环境的影响,采用由弹性橡胶和压电堆作动器组成的主动悬置(active control mount, ACM).针对压电堆作动器输出位移较小的情况,设计液压位移放大机构.通过对压电作动器和橡胶主簧性能的分析,建立由主动悬置构成的隔振系统的力学模型.周期性机械振动系统,其周期振动信号可用作控制同步信号,因此控制系统采用基于同步滤波-X LMS(least mean square)算法的自适应控制策略,传递到机座的残余力作为误差信号,实现对周期性机械振动系统的主动控制.计算机仿真实验结果表明,采用这种主动悬置和同步滤波-X LMS算法的主动控制系统,相对于采用普通橡胶悬置的被动系统,明显减少了对底座的力传递,减振效果明显.

ALGORITHM OF ACTIVE CONTROL FOR PERIODIC MECHANICAL VIBRATIONS

In order to improve the property of periodic mechanical vibration isolation, reduce its influence to the fundament(floor) and environment from periodic mechanical vibrations, adopt an active control mount(ACM) which consists of elastic rubber and piezoelectric stack actuator in the system. A hydraulic mechanism is used in the ACM to achieve higher displacements. Through the analysis of the property of the rubber and piezoelectric stack actuator, a mechanical model of the active vibration isolation system with the active mount is established. For a periodic mechanical vibration system, the vibration pulse of machinery can be availed to control synchronization signal for active system, thus choose an adaptive control strategy based on the synchronized filtered-X LMS (least mean square) algorithm to control the system. The residual force transmitted to the fundament through the mount detected as an error signal, then achieved active control to periodic mechanical vibration system through the ACM. Simulation shows the active system has a better consequence in reducing the transmitted force significantly with respect to the ACM and the adaptive control than that in the passive system.