Research On Path Planning For Mobile Robots

With the improvement of people’s living standard and scientifictechnology, robots begin to access families to assist the people’s daily lives.The key to complete tasks for mobile robots is path planning. With theworking environment of mobile robots becoming more and more complex,there are higher requirements for path planning.The DPSS algorithm based on grid map is used to complete global pathplanning under known environment firstly. There are two improvements ofDPSS algorithm. The path evaluation functions are used to get path lengthshorter, tuning angle smaller. The path smoothing method is used to make thepath is not bound by grid map and more smooth. Simulation results verify thepracticability and validity of the proposed improved method.For the local path planning based on current environment informationobtaining from sensors, the improved VFH+algorithm is proposed based onlaser range finder. Compared with traditional VFH+algorithm based onultrasonic ranging sensor, the method on information acquisition andprocessing are made corresponding improvement. Matlab simulation results demonstrate the improved VFH+algorithm can efficiently complete localpath under unknown environment.The multilayer path planning is proposed under dynamic environmentin this paper. There are three layers for the multilayer path planning. They arethe global path planning layer, the dynamic window path planning layer andthe local path planning layer. Based on the global map, the global planninglayer generates the shortest path from the starting state to the target state,using the DPSS algorithm. Based on the robot’s sensors, the local planninglayer selects a node in the global path as the current target, and generates asmooth path planning which conforms to the kinematic constraints and avoidsdynamic obstacles, by using the VFH+algorithm. The dynamic windowplanning will be enabled when the sub-goal point is blocked or the robot istrapped. The optimal path will be generated in the dynamic window, and thenodes of the path will be the new sub-goals of the local path planning. A newglobal path will be regenerated in the global path planning layer when thedynamic window layer unable to make effective path. The multilayer pathplanning can not only generate a global optimal path, but also improve thereal-time of the path planning because of the addition of dynamic planninglayer. The simulation results verify the feasibility and effectiveness of theproposed multilayer path planning method.