主动减振并联机构模态分析

Modal Analysis of Active Vibration-Controlled Parallel Mechanism

为了缓解在运输过程中由于路面颠簸、加减速、急转弯等对病人造成的不舒适,提出了一种基于柔顺驱动的减振平衡并联机构。该机构综合利用了主动减振与被动减振的特点,对于低频大振幅信号利用伺服运动实现主动减振,而对于高频小振幅振动信号则利用柔顺单元的被动减振特性实现抑振。并利用等效质量法对系统进行了模态分析。仿真结果显示,对于20 Hz以上的线振动信号利用柔顺单元的被动特性可以实现20 d B的衰减。

In order to reduce the discomfort caused to patients in the transport process due to road bumps,acceleration and deceleration,sharp turns,this paper presents an active vibration-controlled and balance-controlled parallel mechanism based on series elastic actuator. This mechanism takes both advantages of active and passive vibration control.It not only can use servo motion to actively reduce the low frequency but high magnitude vibration,but also can use the passive characteristics of compliant unit to isolate thehigh frequency vibration. In the paper,we analyzed the system modal by using equivalent mass method. And the simulation result shown that it can reduce the linear vibration beyond 20 Hz by 20 dB by using the passive characteristic of compliant unit.