Decentralized Motion Control for Omnidirectional Mobile Platform-Tracking a Trajectory Using PD Fuzzy Controller

The development of intelligent mobile robot has become an important and active research topic in the face of emerging markets for autonomous guided vehicle and service mobile robot. In this paper, a new decentralized algorithm for motion control of omnidirectional mobile platform (OMP) with three sets of omnidirectional wheel is introduced. The proposed OMP is a platform with three sets of omnidirectional wheel arranged equally spaced at 120 degrees from one to another. In this decentralized algorithm, the motion of OMP is separated into three independent components of motion expressed in body coordinate frame including rotational moving, horizontal moving and vertical moving. By using omnidirectional wheels, these motion components can be controlled simultaneously as well as separately. The OMP uses a laser-based sensor for recognizing its position and orientation. Based on the proposed decentralized algorithm and OMP's configuration measured by laser sensor, a trajectory tracking control method using fuzzy logic is applied to control the OMP. The use of fuzzy logic for control law makes the proposed system insensitive to parametric uncertainty, load and parameter fluctuations, while guaranteeing stability. The effectiveness of the proposed system is demonstrated by simulation and experimental results.