Stick-slip piezoelectric actuators are widely used in precision engineering due to their high accuracy and small size. However, most of these actuators achieve multi-DOF motion by serially connecting multiple units, resulting in a non-compact structure and large assembly errors.To resolve this issue, this paper proposes a spherical actuator consists of a rotor and four drive units distributed around the rotor. Each drive unit comprises a piezoelectric shear stack and a piezoelectric plate. By utilizing the cooperation of piezoelectric elements, various driving modes with different performance and control complexity can be switched. To understand the influence of position and orientation of the drive units on the actuator’s performance, a dynamic model describing the behavior of the proposed actuator is established. This model takes into account the behavior of the drive units, friction and motion transmission between the drive units and the rotor, as well as transformation of coordinates. Finally, a prototype is developed based on the design, and the three-DOF motion performance of the prototype is tested under different drive modes. This work contributes to the mechanical design of multi-DOF precision positioning devices and the study of motion modes.

中文翻译：

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由协作压电单元驱动的三自由度多模式球形执行器


粘滑式压电执行器由于其精度高、尺寸小而广泛应用于精密工程中。然而，这些执行器大多通过串联多个单元来实现多自由度运动，导致结构不紧凑且装配误差较大。为了解决这个问题，本文提出了一种由转子和分布在周围的四个驱动单元组成的球形执行器。转子。每个驱动单元包括压电剪切叠堆和压电板。利用压电元件的配合，可以切换不同性能和控制复杂度的多种驱动模式。为了了解驱动单元的位置和方向对执行器性能的影响，建立了描述所提出的执行器行为的动态模型。该模型考虑了驱动单元的行为、驱动单元与转子之间的摩擦和运动传递以及坐标变换。最后根据设计开发了样机，并在不同驱动模式下测试了样机的三自由度运动性能。该工作有助于多自由度精密定位装置的机械设计和运动模式的研究。