US Patent 9708000 Trajectory planner for a trailer backup assist system

In one embodiment of the disclosed subject matter, a trailer backup assist system includes a state estimator that determines a current position of a trailer relative to a waypoint position. In addition, the trailer backup assist system includes a trajectory planner that generates first and second circular trajectories tangent to one another spanning between the current and waypoint positions. The trailer backup assist system also includes a controller that reverses the trailer to the waypoint position along the first and second circular trajectories, which are dynamically regenerated as the trailer reverses along the first circular trajectory.