压电陶瓷驱动微小型机器人的运动分析与仿真

摘要

为满足桌面工厂对机器人在平面内大行程、高精度和全方位运动的要求,研制了一种压电陶瓷驱动的微小型机器人.该机器人采用stick-and-slip运动原理,通过压电陶瓷和电磁铁的配合动作,在铁磁性工作表面上实现了前进、后退、左转、右转和原地旋转运动.在假设平行配置的压电陶瓷驱动器在每一步的运动过程中保持平行基础上,分析了一步运动中机器人的4个支撑脚的坐标变化情况,进而推导出在该条件下反映机器人位姿变化的运动学差分模型.计算结果显示,机器人直线运动最大步长为0.042 0mm,旋转运动最大偏转角度为0.185°/步.通过开环轨迹控制、点-点位姿控制和路径跟踪闭环控制实验,验证了机器人应用于桌面工厂时的可行性.%A PZT ( piezoelectric ceramic)-driven electromagnetic miniature robot which could fulfill the requirement of large range, high precision and omni-direction in a desktop factory was presented.With the cooperation of two electromagnets, the robot was able to move forward/backward, tum left/right , and rotate around its own center based on the stick-and-slip motion principle. On the assumption that the two parallel-setup piezoelectric actuators maintain parallel to each other in one step motion,coordinates of the four standing legs were analyzed, resulting in a locomotive differential model to reflect position and orientation changes. The calculated results showed that the maximum step length in rectilinear movement was 0.0420 mm, while the maximum step degree in rotary movement was 0. 185°/step. Experimental results of open loop trajectory control, point-to-point pose control and closed-loop path following control proved the effectiveness of the miniature robot when used in a desktop factory.