Algorithm 2: expandConfiguration() of basic RRT
Input: random configuration qrand, configuration to expand qnear
Output: configuration reachable from qnear or NULL
1 S = ∅;
2 U = set of robot’s possible control inputs
3 for u ∈ U do
4 q = apply input u to the motion model f (qnear , u) over time Δt;
5 if collisionFree(q) then
6 S = S ∪ {q};
7 end
8 end
9 return closest config. from S to qrand or NULL if S = ∅;
Fig.