Collision-free path planning for a shape-changeable mobile robot in a 3-dimensional environment

The problem of finding a collision-free path for a shape-changeable mobile robot in a 3D environment is studied. In order to solve the problem, a 3D path planner is used. This path planner represents the spaces which are occupied by the robot under different gestures as a set of cuboids of different sizes and uses two levels of planning, i.e. global path planning and local path planning to plan the path for the robot. The global path planner generates a most plausible global path for the robot. Subsequently, the local path planner first represents the free space along the plausible global path by a set of hexahedrons and then generates a connection graph whose vertices are the states of the robot and whose edges are operations of the robot by an expert system. Finally, a collision-free path is searched for in this connection graph