毫米级全方位微机器人结构设计与控制对运动精度的影响研究

运动精度是微操作机器人的一个重要参数。针对一种用于微装配操作的毫米级全方位微机器人，分析了影响其运动精度的两个重要方面，即结构设计与控制。分析了结构设计方面的优点和不足，主要涉及传动系统、轮子的安装等。控制方面涉及路径规划和驱动器电磁微马达等。针对微机器人直线运动的非线性问题，提出了对工作区域进行分区的路径规划控制方法。针对电磁微马达的结构特点，提出了矢量合成、力矩自平衡等特殊的控制方法和思想，将微机器人步进运动精度提高了3倍。应用微机器人进行的微装配实验证明了以上方法的有效性。

Influence of Structure Design and Control for Movement Precision of Millimeters-scale Omni-directional Mobile Microrobot

Movement precision is a crucial parameter for a micromanipulation of microrobot. An omni-directional mobile microrobot for microassembly in a microfactory is presented. The microrobot size is less than one cubic centimeter and is driven by four electromagnetic micromotors with 3 mm diameter. As two important aspects for the microrobot precision, the structure design and control are analyzed. The structure analysis includes the transmission system and the wheels fabrication. The virtues and drawbacks of the microrobot structure for the movement precision are also analyzed. For eliminating the influences of the drawbacks of the microrobot structure, some novel control methods and ideas which include the path planning and micromotors control are introduced. In the path planning control, the whole workspace is divided into four areas in which the moving distances of the microrobot are different. This path planning method is designed to solve the non-linear problem of the microrobot during translational movement. According the structure constrains of the electromagnetic micromotor, the vector synthesis control of the torque is devised and the torque self-balance characteristic is utilized to improve the microrobot precision. Presently, the microrobot can be achieve 0.07mm/step during translation, and 0.83°/setp during steering, which is three times compared with common control method. The microrobot can do simple microassembly micromanipulation supervised by a computer vision system. The microassembly experiment result demonstrates the validity of these microrobot control methods and concepts based on the actual characteristics of the microrobot structure.