Spherical magnetorheological fluid (MRF) robots are capable to move in narrow space, which can be used for drug releasing to human stomach; however, the magnetic-controlled rolling movement often generates a large displacement error, which greatly hinders the practical applications of the MRF robots. In order to bridge this research gap, this paper introduces a new MRF robot with a precise locomotion controller. In this control system, a data acquisition system is designed for the MRF robot and an optimal proportion integration differentiation (PID) controller is proposed based on an improved grey wolf optimization algorithm (IGWO). Both simulations and experiments have been performed to verify the performance of the locomotion controller. The simulation results show that the proposed IGWO-PID controller is superior to the conventional PID and GWO PID controller, with faster response output and smaller overshoot. Experimental analysis results demonstrate the proposed MRF robot can move in a complex trace with a speed fluctuation rate below 5.4%. As a result, precise locomotion has been achieved to make the new MRF robot ready for medicine delivery in narrow space.

球形磁流变液（MRF）机器人能够在狭窄的空间中移动，可用于将药物释放到人的胃中；但是，磁控滚动运动经常会产生较大的位移误差，这极大地阻碍了MRF机器人的实际应用。为了弥合这一研究差距，本文介绍了一种具有精确运动控制器的新型MRF机器人。在该控制系统中，为MRF机器人设计了数据采集系统，并基于改进的灰狼优化算法（IGWO）提出了最优比例积分微分（PID）控制器。仿真和实验均已执行以验证运动控制器的性能。仿真结果表明，提出的IGWO-PID控制器优于传统的PID和GWO PID控制器，具有更快的响应输出和更小的过冲。实验分析结果表明，提出的MRF机器人可以在复杂的轨迹中运动，速度波动率低于5.4％。结果，已经实现了精确的移动，从而使新的MRF机器人可以在狭窄的空间中进行药物输送。