Trajectory Tracking Control of Wheeled Mobile Robots Based on RTK-GPS

Aiming at the trajectory tracking problem of wheeled mobile robots, a trajectory tracking control method based on RTK-GPS (real-time kinematic GPS) is proposed. Firstly, the GPS (global positioning system) trajectory map and the real-time RTK-GPS of the robot are converted to the same plane coordinate system through the proposed coordinate conversion model. Secondly, GPS trip points occur when RTK-GPS is disturbed, so the optimal estimate after filtering with standard Kalman filter is used as the robot's true position. The trajectory map is traversed to find the initial nearest target point, then the target point is updated continuously, and the proportional-derivative controller of angular deviation is adopted to control the steering of the robot in real time. By this way, the trajectory tracking of the wheeled mobile robot is achieved. The experiment is conducted on a modified wheeled mobile robot. Experimental results show that the algorithm has a high reliability. The deviations when tracking the snake-shaped and 8-shaped trajectories are within 0.42 m and 0.67m respectively.