无驱动冗余的纯中心压电黏滑旋转台

Purely Central Piezoelectric Stick-slip Rotary Stage without Driving Redundancy

针对精密位姿调整时的大转角、高分辨率、高承载能力和结构紧凑性能需求,利用压电驱动器驱动柔顺机构设计了具有力增幅特性的纯中心黏滑旋转台。单驱动器致动避免了驱动冗余,同时改变桥式驱动机构的倾斜角度可对夹紧力放大特性进行调整。首先利用混合直圆和叶型柔性铰链的柔顺机构,设计了含有一对中心对称驱动足的桥式机构,并与圆形滑块结合,在放大夹紧力的同时实现无冗余、纯中心转动。然后通过有限元仿真分析了旋转台的单步转角、力放大倍数及应力,并与理论计算结果对比。最后搭建实验测试平台,验证了所设计旋转台的性能。旋转台整体尺寸为86 mm×86 mm×32 mm,在150 V输入电压的作用下,实验测得的最大负载为9 kg,旋转台的角分辨率为0.10μrad。

Given the performance requirements of large rotation angle,high resolution,high load capacity,and compact structure in precision posture adjustment,a purely central stick-slip rotary stage with force magnification characteristics is designed using a piezoelectric actuator to drive compliant mechanisms.Actuation redundancy is avoided by single-actuator driving,meanwhile the clamping force magnification characteristics can be regulated by changing the tilt angle of the bridge driving mechanism.Firstly,compliant mechanisms with hybrid straight circular and leaf-type flexible hinges are used to design a bridge mechanism containing a pair of centrosymmetric driving feet,which are combined with a circular slide to achieve non-redundant,purely central rotation while magnifying the clamping force.Then,the single-step rotation angle,force magnification,and stress of the rotary stage are analyzed by finite element simulation and compared with the theoretical calculation.Finally,an experimental test platform is built to verify the performance of the designed rotary stage.The overall size of the rotary stage is 86 mm×86 mm×32 mm,and the maximum load in experiments is 9 kg with a 150 V input voltage.Also,the angular resolution is 0.10μrad.