Development of 3 DOF Spherical Motor by Means of Walking Drive

研制了一种新型三自由度步进驱动球形电动机，并对其性能进行了测试。步行驱动是本课题研究人员发明的一种新型驱动机构，它采用压电作动器。三对驱动单元或总共六个驱动单元围绕由不锈钢SUS-J制成的直径为3英寸的钢球布置，钢球由三个支撑球支撑。每对驱动单元保持球并在两个正交方向上驱动球表面。通过组合三对独立控制的驱动单元的驱动运动，球可以围绕三个垂直轴旋转。由于每个压电驱动器的行程是有限的，每对驱动单元的驱动运动是交替启动，使球的表面可以连续驱动。设计了三自由度球形电机，并制作了电机样机.开发并实现了球形电机驱动单元的计算机程序.对所研制的球形电机的性能进行了分析。性能的一些典型数据是最大旋转扭矩为0.92 Nm，最大旋转速度为1.06度/秒，跟踪误差为0.16 mdeg。

A new 3 degrees-of-freedom spherical motor driven by means of Walking Drive has been developed and its performances are examined. The Walking Drive is a new driving mechanism invented by the researchers of current project, which utilizes piezo-electric actuators. Three pairs of driving units, or total six driving units are arranged around a 3-inch diameter steel ball made of stainless steel SUS-J, which is supported by three supporting balls. Each pair of the driving units hold the ball and drive the ball surface in two orthogonal directions. The ball can be rotated around the three perpendicular axes by combining the driving motions of the three pairs of the driving units, which are controlled independently. As the stroke of each piezo-electric actuator is limited, the driving motion of each pair of the driving units is activated alternatively so that the surface of the ball can be driven continuously.Major results obtained are as follows :1. 3 DOF spherical motor has been designed and the prototype of the motor has been fabricated.2. The computer programs have been developed and implemented to drive the driving units of the spherical motor.3. The performances of the spherical motor developed have been analyzed. Some typical data of the performances are 0.92 Nm in maximum rotating torque, 1.06 degrees per second in the maximum rotational speed, and 0.16 mdeg in the tracking error.