Breakover angle

Abstract: A vehicle system for estimating a trailer length is disclosed and includes a first sensor for measuring a wheel steer angle and a second sensor for measuring a hitch angle. A processor is in communication with the first and second sensors and is operable to determine a wheel steer angle change and a hitch angle change. The processor performs a first computation if the wheel steer angle change and the hitch angle change satisfy a threshold requirement and performs a second computation if at least one of the wheel steer angle change and the hitch angle change does not satisfy the threshold requirement.

Abstract: A rear wheel steer angle controlling apparatus for vehicles having steerable front and rear wheels, adapted for controlling the steer angle of rear wheels in response to the operation of the steering wheel for steering the front wheels. When the steering wheel is operated quickly, a rear wheel steer angle is formed in the counter direction to the direction of the front wheel steer angle, so that the response to the steering input for turning the vehicle is improved. Conversely, when the steering wheel is operated slowly, a rear wheel steer angle is formed in the same direction as the front wheel steer angle, thus enhancing the stability of the vehicle running straight. When the vehicle is running at a high speed, the rear wheel steer angle is formed always in the same direction as the front wheel steer angle regardless of the speed of operation of the steering wheel, so that the steering stability during high speed running is improved. When a yawing moment is generated due to a disturbance such as lateral wind, the rear wheel steer angle is automatically controlled in such a manner as to negate the yawing moment, thus compensating for the lateral displacement of the vehicle without requiring correcting steering operation by the driver.

Abstract: A system and method of calculating a heading angle for a trailer that is being backed by a vehicle. A trailer backup assist control module, in communication with a hitch angle detecting apparatus, receives a hitch angle and determines displacement of left and right vehicle wheels using information supplied by vehicle wheel speed sensors while the vehicle is backing the trailer. A vehicle heading angle is determined using left and right wheel displacement information and a known vehicle track width. A trailer heading angle is then calculated using the vehicle heading angle and the hitch angle.

Abstract: A vehicle control system that selectively provides rear-wheel steering to prevent a vehicle-trailer from jackknifing during a back-up maneuver. The system senses a steering angle of the vehicle, a speed of the vehicle and a hitch angle between the vehicle and the trailer. The system calculates an equilibrium hitch angle that is a steady-state hitch angle position based on the steering angle and the vehicle speed, and a pseudo-equilibrium hitch angle that is a steady-state hitch angle at a maximum rear-wheel steering input based on the steering angle and the vehicle speed. The system then determines whether the rear-wheel steering should be provided based on a predetermined relationship between the sensed hitch angle, the equilibrium hitch angle and the pseudo-equilibrium hitch angle.