To solve the problem that the basic RRT algorithm for UAV path planning can only quickly get feasible path
unable to obtain near optimal path
an improved RRT algorithm is proposed.The algorithm takes into account the dynamic constraints of UAV
by introducing the path length constraint and improving the selection strategy for root node that nearest to the random sample point
the search tree will explore along the direction of the near optimal path.Flyable path is generated by using B-spline curves for path smoothing.Simulation results demonstrated that this proposed method can complete UAV path planning mission quickly and effectively.