磁弹性微型游泳机器人在外部干扰和复杂路径下的精确跟踪控制

Accurate Tracking Control of Magnetoelastic Elastic Miniature Swimmer under External Disturbance and Complex Path

基于磁弹性复合材料设计一种毫米级微型游泳机器人,利用三维亥姆霍兹线圈实现空间均匀磁场对机器人的无缆驱动,通过时变旋转磁场来改变机器人的运动姿态,从而实现机器人的游泳动作。介绍微型游泳机器人结构及制作流程,并利用Abaqus建立仿真模型,通过有限元仿真和试验对机器人的游泳特性进行对比分析,研究磁场频率、强度对游泳速度的影响。在此基础上,采用改进型视距导航控制方法提高游泳机器人的抗干扰能力,同时提出一种速度模糊自适应算法和头尾转换控制实现了对复杂规划路径的精确跟踪,试验结果表明,该算法能克服常规匀速视距导航控制易发生跟踪点丢失、无法再次回归跟踪路径等缺点,并能很好地减小路径跟踪误差,为磁控微型游泳机器人的精确控制提供了新思路。

A millimeter-scale miniature swimming robot is designed based on magnetoelastic composite material. In order to realize the cable-less driven for the swimmer, spatial uniform magnetic fields are set up through 3D Helmholtz coils. The motion posture of the swimmer is changed by time-varying rotating magnetic field, so as to realize the swimming action of the robot. The structure and production process of the swimmer is introduced, and the simulation model is established based on Abaqus. Comparing finite element simulation and experimental results, the swimming characteristics of the robot are analyzed, and the influence of the frequency and strength of magnetic field on the swimming velocity is discussed. Furthermore, a modified line-of-sight navigation control method is adopted to improve the anti-disturbance ability of the swimmer, and a velocity fuzzy adaptive algorithm and head-to-tail switch control are proposed to realize the high accurate tracking of the complex path. The experimental results show that the proposed algorithm can overcome the disadvantages of the conventional line-of-sight navigation control with uniform velocity, such as missing of waypoints and the inability to relocate the path under certain situations, etc., and can reduce the error of path following. This work may provide a new idea for the precise control of the magnetic miniature swimmer.