Vector model-based robot-assisted control system for a wheeled mobile robot

ABSTRACT A robot-assisted control system based on the vector model is proposed for a wheeled mobile robot. According to the closed-loop control structure, the system is constituted of two parts – localization and path planning. The localization algorithm, which is enhanced from Monte Carlo localization, is more effective, stable, and robust than the traditional algorithm because of using many strengthening mechanisms, such as using a vector model, re-initialization, and reverse convergence. The path planning algorithm includes three stages to obtain a path with a motion plan. Firstly, a path from the current position to the goal is planned by an enhanced A* algorithm. Secondly, a smooth mechanism is applied to the path to obtain the continuity of orientation. Finally, a motion design based on the trapezoidal-curve velocity profile is implemented to the smoothed path in both linear and angular velocities to obtain the estimated moving time, position schedule, and velocity schedule. With the assisted control system, the robot knows its current position, the path with motion planning to the destination and its estimated arrival time. If the robot deviates from the move plan, the system will reschedule based on the current state. The experimental results show the great performance of our proposed method.