压电陶瓷驱动的快刀伺服技术是加工光学自由曲面等复杂曲面的有效方法。为了突破压电陶瓷驱动快刀伺服机构的行程局限, 本文采用二级杠杆放大机构, 设计了一种压电陶瓷驱动的长行程快刀伺服机构, 实现了快刀伺服机构的长行程输出性能并消除了机构的寄生位移。基于伪刚体模型和拉格朗日原理对机构进行了动力学建模, 综合行程和固有频率性能优化了机构参数并进行了有限元仿真和实验验证。机构等效刚度和固有频率的理论模型和有限元仿真结果误差分别为6.4%和1.6%, 验证了理论模型的有效性。实验结果进一步表明, 所设计的快刀伺服机构可实现100 μm的输出行程同时具有730 Hz的固有频率, 验证了所设计机构用于快刀伺服加工的有效性。系统的闭环跟踪实验也验证了系统良好的跟踪性能。

Piezo-actuated Fast Tool Servo(FTS) technology is apromising method for processing complex surfaces such as optical free-form surfaces. To break through the stroke limitation of the piezo-actuated FTS mechanisms, a piezo-actuated long-stroke FTS mechanism was designed with a two-stage lever amplifying mechanism in the present paper; this effectively improved the long-stroke output performances of FTS mechanisms and eliminated parasitic displacement. The dynamic model of the mechanism was discussed based on the pseudo-rigid body model and Lagrangian principle. The mechanism parameters were optimized by synthesizing the stroke as well as the natural frequency performance; Finite Element Analysis(FEA) and experimental verification were also carried out. The errors of equivalent stiffness and the natural frequency of the mechanism between the theoretical model and FEA are 6.4% and 1.6%, respectively, validating the theoretical model. The experimental results show that the designed FTS mechanism can achieve a 100-μm output stroke and 730 Hz natural frequency, which agrees well with the analysis and simulations. The closed-loop tracking experiments of the designed system are also given, demonstrating the design's adequatetracking performance.