Motion Control of Mobile Robots in Indoor Dynamic Environments

This paper presents a motion control method for mobile robots in partially known dynamic indoor environments based on integration of path planning search algorithm and dynamic window local obstacle avoidance algorithm. Three different graph based search algorithms for global geometrical path planning are considered and compared: A*, D* and focussed D* algorithm. The global geometric path in a grid map is further transformed to a robot trajectory by taking into account the kinematic and dynamic robot constraints. In the presented work, dynamic window local obstacle avoidance generates the admissible robot trajectories that ensure safe robot motion. A simple and efficient procedure to the selection of appropriate motion commands based upon alignment of acquired trajectories and global geometric path is proposed. The initial a priori knowledge about the environment is used in the form of the occupancy grid map that is incrementally updated in runtime. The algorithms are verified both by simulation and experiments with a Pioneer 2DX mobile robot equipped with laser range finder.