Improved Follow the Gap Method for Obstacle Avoidance

Follow the Gap Method (FGM) is a safety-focused geometric obstacle avoidance algorithm for local navigation. In this method, the largest gap around the robot is selected and the robot moves towards a goal point considering the largest gap and minimum distance to obstacle. One of the drawbacks of the method is the extension of the path which sometimes happens unnecessarily. Another drawback comes from small differences between the gap sizes. This sometimes makes the robot to change the selected gaps instantly which causes zigzag trajectories. In this paper, Improved Follow the Gap Method (FGM-I) is presented to eliminate these two drawbacks. In FGM-I, the gaps are selected according to a new utility function and unnecessary gap changes are penalized. A differential drive powerchair is used in simulations. The simulation results show that the FGM-I reduces the effects of the mentioned problems seriously.