US Patent 9623904 Trailer curvature control with adaptive trailer length estimation

An apparatus for determining a jackknife condition of a vehicle and trailer is disclosed. The apparatus comprises a processor operable to set an operating range of a hitch angle to a minimum range. The processor monitors the hitch angle while the vehicle is operated in a forward direction and increases the operating range based on the hitch angle observed during the monitoring. The processor is further operable to utilize the increased operating range to prevent a jackknife condition during a guided reverse operation of the vehicle.