微/纳米定位平台的桥式机构静、动态优化设计

Static and dynamic optimal design of bridge-type mechanism of micro/nano-positioning platform

为了解决桥式机构静态性能与动态性能相互制约问题,应用伪刚体模型法,建立桥式机构的静、动力学模型,分析表明:柔性板簧厚度越小、长度越长,桥式机构的静态性能越好,但动态性能就越差;动态性能主要受柔性板簧厚度影响,板簧长度对其影响不大.为了优化桥式机构的静、动态性能,建立该机构总性能的优化模型,并对柔性板簧厚度、长度等几何特征参数进行了优化设计.应用ANSYS,对优化前、后的机构进行了仿真分析,并对机构的静、动态性能进行了试验,结果表明:优化后机构的稳态时间减小为0.032s,比优化前ANSYS仿真缩短了80%,微位移输出减小了40.2%,优化后机构总性能达340.75mm·Hz,比优化前ANSYS仿真提高了74.53%.

In order to solve the restriction between static and dynamic performances,static and dynamic models were set up by using pseudo-rigid-body and the effect of geometric parameters on the static and dynamic performances was analyzed.As a result,the smaller the thickness and the longer the length of flexure hinge are,the better the static performance of the bridge-type mechanism will be,while the dynamic performance goes worse.The dynamic performance is mainly affected by the thickness of flexure hinge,while much less by the length.An optimization model of overall performance of bridge-type mechanism was established,and the thickness,length and other geometric parameters were optimized.In terms of ANSYS,the performances of the mechanism before and after optimization were simulated,and its static and dynamic performances were tested.Experimental results indicated that the stable time after optimization was decreased to 0.032 s,80% shorter than before optimization,the displacement output decreased by 40.2%,while the overall performance increased to 340.75 mm·Hz,increased by 74.53% than before optimization.