Abstract: A torque distribution system for a vehicle permits the transfer of torque between vehicle wheels using a selectively engagable clutch that is hydraulically engaged using hydraulic pressure provided by a hydraulic transmission pump driven by the engine, allowing for enhanced system functionality and reduced part content in comparison with known torque distribution systems. The system may include an “active-on-demand” clutch that is selectively engagable to transfer torque between a front differential and a rear differential (thereby transferring torque from the front wheels to the rear wheels) as well as an electronically-limited slip differential clutch selectively engagable to transfer torque from one front wheel to the other front wheel through the front differential. Utilization of the transmission hydraulic pump allows pressure to be provided to engage the clutch even when the wheels are stationary, i.e., to launch the vehicle.

Abstract: Apparatus and methods are provided for modifying a torque differential between the road wheels of a non-driven axle. One apparatus includes, but is not limited to, two non-driven shafts and a torque transfer modulator coupling the two non-driven shafts. The torque transfer modulator is configured to modify the torque differential between the two non-driven shafts. A motor vehicle includes, but is not limited to, the apparatus coupling left and right road wheels, a sensor for detecting a left turn and/or right turn, and a controller. The controller is configured to transmit an actuating signal to the torque transfer modulator in response to the turn. One method includes, but is not limited to, detecting a driving condition in a motor vehicle, subtracting an amount of torque from a first non-driven road wheel, and adding the amount of torque to a second non-driven road wheel in response to detecting the driving condition.

Abstract: A torque distribution system for a vehicle permits the transfer of torque between vehicle wheels using a selectively engagable clutch that is hydraulically engaged using hydraulic pressure provided by a hydraulic transmission pump driven by the engine, allowing for enhanced system functionality and reduced part content in comparison with known torque distribution systems. The system may include an “active-on-demand” clutch that is selectively engagable to transfer torque between a front differential and a rear differential (thereby transferring torque from the front wheels to the rear wheels) as well as an electronically-limited slip differential clutch selectively engagable to transfer torque from one front wheel to the other front wheel through the front differential. Utilization of the transmission hydraulic pump allows pressure to be provided to engage the clutch even when the wheels are stationary, i.e., to launch the vehicle.

Abstract: Methods and apparatus are provided for determining the intent of a driver of a motor vehicle in moving a trailer towed by the motor vehicle along a desired path. The method comprises the step of positioning a first reference point at a first location spaced apart from the motor vehicle and sequentially positioning a second reference point at a plurality of way points along the desired point. A signal relative to the motor vehicle, the first reference point, and the plurality of way points is transmitted as the second reference point is positioned at each of the way points. The transmitted signals corresponding to each of the way points are received and are used to determine the position of the plurality of way points relative to the motor vehicle by a process of triangulation. The position of the plurality of way points indicate positions along the desired path.

Abstract: Methods and apparatus are provided for determining the intent of a driver of a motor vehicle in moving a trailer towed by the motor vehicle along a desired path. The method comprises the step of positioning a first reference point at a first location spaced apart from the motor vehicle and sequentially positioning a second reference point at a plurality of way points along the desired point. A signal relative to the motor vehicle, the first reference point, and the plurality of way points is transmitted as the second reference point is positioned at each of the way points. The transmitted signals corresponding to each of the way points are received and are used to determine the position of the plurality of way points relative to the motor vehicle by a process of triangulation. The position of the plurality of way points indicate positions along the desired path.

Abstract: A method directed to improving the stability of a motor vehicle having front and rear steering capabilities includes determining a coefficient of friction of the road surface with which the motor vehicle is engaged and adjusting a phase gain function of a rear steering mechanism to compensate for the steerability of the motor vehicle over the road surface. A system for improving the stability of a motor vehicle having front and rear steering capabilities includes a control unit, a front steering mechanism in informational communication with the control unit, and a rear steering mechanism in informational communication with the control unit. The rear steering mechanism is responsive through the control unit to road conditions of the road surface.

Abstract: An all wheel steering system for a vehicle comprising a controller having a first input for receiving a signal from a hand wheel position sensor, a second input for receiving a signal from a vehicle speed sensor, and a third input for receiving a signal that varies depending upon whether a trailer is hitched the vehicle. The controller generates an output for controlling a rear wheel steering actuator. The output varies as a function of the first, second, and third inputs such that when a trailer is hitched to the vehicle the out-of-phase rear steer amount at low speeds is reduced and the in-phase rear steering amount at high speeds is increased.

Abstract: The above discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by an all-wheel steering system for a vehicle comprising a controller having a first input for receiving a signal from a hand wheel position sensor, a second input for receiving a signal from a vehicle speed sensor, and a third input for receiving a signal that varies depending upon whether a trailer is hitched to said vehicle. The controller generates an output for controlling a rear wheel steering actuator. The output varies as a function of the first, second, and third inputs such that when a trailer is hitched to said vehicle the out-of-phase rear steer amount at low speeds is reduced and the in-phase rear steering amount at high speeds is increased.

Abstract: A vehicle steering mechanism to compensate for instabilities including a vehicle frame, a front axle coupled to the vehicle frame, the front axle further coupled to two front wheels, a rear axle coupled to the vehicle frame, the rear axle further coupled to two rear wheels, an actuator for changing the direction and angle of the two rear wheels, a trailer hitch coupled to the frame, at least one sensor for measuring instability in the trailer hitch, a controller processing the measured instability, and where the controller controls the actuator and the direction and angle of the two rear wheels to compensate for the measured instability.

Abstract: A method of swing out compensation in a vehicle with rear wheel steering, comprising: obtaining a zero speed status signal representative of when a vehicle is at zero speed; establishing a rear wheel angle threshold; obtaining a calculated rear wheel angle; and generating a commanded rear wheel angle responsive to the rear wheel angle threshold and the calculated rear wheel angle, whichever is of smaller magnitude. A swing out compensation system for a vehicle with rear wheel steering, the system comprising: a controller; and a rear steering mechanism in communication with and responsive to the controller; wherein the controller generates a commanded rear wheel angle responsive to one of a rear wheel angle threshold and a calculated rear wheel angle, whichever is of smaller magnitude.

Abstract: A vehicle steering mechanism to compensate for instabilities including a vehicle frame, a front axle coupled to the vehicle frame, the front axle further coupled to two front wheels, a rear axle coupled to the vehicle frame, the rear axle further coupled to two rear wheels, an actuator for changing the direction and angle of the two rear wheels, a trailer hitch coupled to the frame, at least one sensor for measuring instability in the trailer hitch, a controller processing the measured instability, and where the controller controls the actuator and the direction and angle of the two rear wheels to compensate for the measured instability.

Abstract: A method is disclosed for controlling the rear wheel angle in a four-wheel steering vehicle such as a pickup truck. The front wheels are steered using the conventional operator handwheel linked to the front wheels. The rear wheels are actuated with a reversible electric motor and the rear wheel angle controlled using a computer with inputs of vehicle velocity, operator handwheel position and correlated front wheel angle, and handwheel turning rate. Control of rear wheel angle starts with a correlation of ratios of rear wheel angle to front wheel angle, R/F, vs. vehicle velocity suitable, determined under steady state front steering angle and velocity conditions, to maximize the contribution of the rear wheels while avoiding side-slip of the vehicle.

Abstract: A method is disclosed for controlling the rear wheel angle in a four-wheel steering vehicle such as a pickup truck. The front wheels are steered using the conventional operator handwheel linked to the front wheels. The rear wheels are actuated with a reversible electric motor and the rear wheel angle controlled using a computer with inputs of vehicle velocity, operator handwheel position and correlated front wheel angle, and handwheel turning rate. Control of rear wheel angle starts with a correlation of ratios of rear wheel angle to front wheel angle, R/F, vs. vehicle velocity suitable, determined under steady state front steering angle and velocity conditions, to maximize the contribution of the rear wheels while avoiding side-slip of the vehicle.

Abstract: A method directed to improving the stability of a motor vehicle having front and rear steering capabilities includes determining a coefficient of friction of the road surface with which the motor vehicle is engaged and adjusting a phase gain function of a rear steering mechanism to compensate for the steerability of the motor vehicle over the road surface. A system for improving the stability of a motor vehicle having front and rear steering capabilities includes a control unit, a front steering mechanism in informational communication with the control unit, and a rear steering mechanism in informational communication with the control unit. The rear steering mechanism is responsive through the control unit to road conditions of the road surface.

Abstract: Disclosed is a method of swing out compensation in a vehicle with rear wheel steering, comprising: obtaining a zero speed status signal representative of when a vehicle is at zero speed; establishing a rear wheel angle threshold; obtaining a calculated rear wheel angle; and generating a commanded rear wheel angle responsive to the rear wheel angle threshold and the calculated rear wheel angle, whichever is of smaller magnitude.

Abstract: Disclosed is a method of determining an estimate of zero speed of a vehicle, the method comprises obtaining or acquiring a drive train status signal, a brake signal, a parking brake signal, a vehicle speed signal, and a throttle position signal. The method further comprises formulating a zero speed status signal under selected conditions to in response to at least one of the abovementioned signals.