空间对称弹簧支链Stewart机构多维隔振特性

Study on Multi-dimensional Vibration Isolation of Stewart Mechanism With Symmetric Space Spring Chains

为解决不平顺路况运行车辆及随机波浪中船体的多维振动问题,介绍了一种空间对称弹簧支链的Stewart六自由度并联隔振机构,主要针对该类机构的隔振性能进行研究。首先建立了机构的3维模型,采用动力学逆解方法推导了机构的加速度二阶影响系数矩阵。基于多自由度动力学系统传递函数模型推导了模态参与因子,利用ADAMS/Vibration模块进行机构仿真模态分析,获得隔振平台输出加速度的模态参与因子及其主要模态振型与对应峰值。在0.1-1000Hz频域段内对该模型进行受迫振动分析,获得机构隔振平台位移时域及加速度频响曲线,基于功率流传递函数模型对其隔振性能进行评价。研究结果表明:含空间对称弹簧支链的Stewart并联机构在较宽的频段内具有显著的多维隔振效果,能够实现微幅低频振动的隔离。

In order to solve the problem of multi-dimensional vibration of vehicles running on irregular road conditions and ship hulls in random waves, Stewart parallel vibration isolation mechanism with spatial symmetrical spring chains is introduced, and its vibration isolation performance is studied. Firstly, the three-dimensional model of the mechanism is established, and the second-order influence coefficient matrix of the acceleration of the mechanism is deduced by using the inverse dynamic solution method. The modal participation factor is deduced based on the transfer function model of multi-degree-of-freedom dynamic system,. The simulation modal analysis is carried out by using ADAMS/Vibration and the modal participation factor of the output acceleration of the vibration isolation platform, its main modal modes and corresponding peaks are obtained. The forced vibration of the model is analyzed in the frequency domain of 0.1-1000 Hz. The displacement time domain and acceleration frequency response curves of the vibration isolation platform are obtained. The vibration isolation performance of the platform is evaluated based on the power flow transfer function model. The results show that the Stewart parallel mechanism with spatially symmetrical spring chains has remarkable multi-dimensional vibration isolation effect in a wide frequency band, and can achieve the isolation of small amplitude and low frequency vibration.