Abstract: An improved path planning for mobile robot in unknown environment is proposed, in which the Bug algorithm and rolling path planning are combined. The cubic spiral for mobile robot path tracking is well studied here and some excellent characteristics are found. Then the cubic spiral curve is used to smooth the collision-free path by defining the cost functions of path for smoothness. Therefore the mobile robot is easy to track and the application field of mobile robot is extended. At last the proof of convergence and completeness is given. Simulation results verify the effectiveness of this method.

Key words: computer application, mobile robot, path planning, cubic spiral curve, rolling windows