Robust subgoal planning and motion execution for robots in fuzzy environments

In this paper, a fuzzy environment includes obstacles in the vicinity of robot motion, which cannot be modelled exactly or are entirely unknown, and a vague description of the relationship between the robot and the obstacles. An integrated concept for solving the problem of motion planning and control of robots in fuzzy environments is proposed. First, critical points for the desired motion are found in a connectivity network on the boundary of static obstacles. By considering the degree of uncertainty of the obstacles, the local geometry, the available free space and the path shape, these points are further adjusted to form subgoals which reliably decide the global motion direction. During on-line motion execution, a fuzzy controller evaluates sensor data, realizes the motion towards subgoals and avoids local unexpected collisions. Simulations with mobile robots show some control results using this concept