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设计一种新型的6自由度精密微动平台,并对其静态和动态性能进行分析。利用3对不同方位的柔性铰链设计一种能实现6自由度运动的柔性运动支链,且支链结构设计在同一平面,将2对支链对称放置形成结构紧凑和高强度的微动平台。采用有限元软件ANSYS对平台进行柔度和运动学分析,分析结果表明对称支链1和3能产生Z和Y方向平动和绕X和Y的转动,而对称支链2和4能产生X和Y方向平动和绕Z和Y的转动,所以平台能实现6自由度运动,2对对称支链可以实现运动互补且具有部分运动解耦性。对平台进行灵敏度分析表明输出位移与输入位移为线性关系,平台沿X和Z方向的位移灵敏度相同,绕X和Z方向转角灵敏度相近,但Y方向灵敏度较小,说明平台在Y方向上运动性能不如其他方向的。对平台进行模态分析,从振型可看出其可实现6自由度方向的运动,并分析了在有和无预应力两种情况下的固有频率,两者差值范围为16.8%~33.9%,说明预应力对平台的固有频率有较大影响。
A new 6-DOF precision fretting platform is designed and its static and dynamic performance are analyzed. A flexible moving branch with 6 degrees of freedom is designed by using 3 pairs of flexible hinges with different orientations. The branch structure is designed on the same plane. Two pairs of branches are symmetrically placed to form a compact and high-intensity platform. The finite element software ANSYS is used to analyze the platform’s flexibility and kinematics. The results show that the symmetrical branches 1 and 3 can produce the translation in the Z and Y directions and the rotation around the X and Y. The symmetrical branches 2 and 4 can generate X And the Y direction of translation and rotation around the Z and Y, so the platform can achieve 6 degrees of freedom of movement, two pairs of symmetrical branches can be complementary to each other with some movement and decoupling. Sensitivity analysis of the platform shows that the output displacement has a linear relationship with the input displacement. The displacement sensitivity of the platform in the X and Z directions is the same, the sensitivity around the X and Z directions is similar, but the sensitivity in the Y direction is small, indicating the movement performance of the platform in the Y direction Not as good as other directions. The modal analysis of the platform shows that it can realize the motion of 6 degrees of freedom from the mode shapes, and analyzes the natural frequency under both the presence and absence of prestress, the difference between the two ranges from 16.8% to 33.9 %, Indicating that the prestress has a greater impact on the natural frequency of the platform.