Motion planning for omni‐directional mobile robots based on anisotropy and artificial potential field method

Purpose – The purpose of this paper is to propose a suitable motion planning for omni‐directional mobile robots (OMRs) by taking into account the motion characteristics. Design/methodology/approach – Based on the kinematic and dynamic constraints, the maximum velocity, motion stability and energy consumption of the OMR moving in different directions are analysed, and the anisotropy of the OMR is presented. In order to obtain the optimal motion, the path that the robot can take in order to avoid the obstacle safely and reach the goal in a shorter path is deduced. According to the new concept of anisotropic function, the motion direction derived from traditional artificial potential field (tAPF) is regulated. Findings – A combination of the anisotropic function and tAPF method produces high‐speed, highly stable and efficient motion when compared to the tAPF. Simulations and experiments have proven the validity and effectiveness of this method. Research limitations/implications – The practical factors, such as the effect of wear on the omni‐directional wheels, are not considered. Typical problems of APF, e.g. local minima, are not addressed here. In our future research, we will deal with these issues. Practical implications – The proposed motion planning is applicable for any kind of OMRs, both three‐ and four‐wheeled OMRs, which can fully exhibit the advantages of OMRs. Originality/value – The new concept of an anisotropic function is proposed to indicate the quality of motion in different directions. Different motion effects can be obtained in the same direction with different weights denoted by the anisotropic function, i.e. different trade‐offs can be achieved by varying the weights.