Abstract: An automotive vehicle steering system has an actuator (12) for steering a wheel (10). A shaft (28) passes axially through the interior of a housing (14) of the actuator and through a rotor tube (56) journaled for rotation within the housing. On the exterior of the housing one end of the shaft is coupled to the wheel. An electric motor (52) within the interior of the housing rotates the rotor tube when the wheel is steered by a steering wheel. An internal screw thread (68) on the rotor tube and an external screw thread (70) on the shaft are operatively coupled by a set (74) of transmission rollers (76) to provide for bi-directional transmission of motion between the rotor tube and the shaft such that rotation of the rotor tube causes the shaft to move axially of the housing to steer the vehicle wheel and axial motion of the shaft due to wheel recovery from a turn rotates the rotor tube.

Abstract: The present invention involves a system and method of controlling a vehicle steer-by-wire system to provide the variable and adjustable steering feel for the driver utilizing expert-type fuzzy logic technology. The steering wheel fuzzy logic controller controls the steering wheel torque to produce the variable and adjustable steering feel continuously based on changes in steering wheel angle, road wheel torque and vehicle speed.

Abstract: One aspect of the present invention regards an automotive steering wheel control system having a steering wheel, a magnetorheological damper in communication with the steering wheel and a road wheel control system operably connected to the magnetorheological damper where the magnetorheological damper controls the steering wheel in response to a torque signal from the road wheel control system.

Abstract: The present invention involves a system and method of controlling a vehicle steer-by-wire system to provide the variable and adjustable steering feel for the driver utilizing expert-type fuzzy logic technology. The steering wheel fuzzy logic controller controls the steering wheel torque to produce the variable and adjustable steering feel continuously based on changes in steering wheel angle, road wheel torque and vehicle speed. The method comprises receiving an actual steering wheel angle, an actual road wheel angle, an actual road wheel torque, and an actual vehicle speed. The method includes converting the actual input variables into values in fuzzy sets based on their membership functions with linguistic term labels. The method further includes inferring a reaction torque control variable using fuzzy logic inference rules. The method includes converting a fuzzy reaction torque control variable into an actual reaction torque control variable.

Abstract: A differential gear assembly including a differential housing and a ring gear mounted externally to the differential housing by a clamp. The differential housing and the ring gear each include an annular flange extending therefrom and the clamp includes a pocket which is adapted to receive the annular flanges therein. In another aspect, the flanges include opposing angled surfaces and the pocket includes opposing angled sides, whereby when the clamp is placed to the flanges, the angled surfaces of the flanges engage the angled sides of the clamp such that the clamp provides an axial clamping force to the flanges.

Abstract: The present invention involves a system and method of simulating a steering resistance torque on a vehicle steering wheel of a steer-by-wire system. The steer-by-wire system uses a magnetorheological device and a motor to apply torque on the steering wheel for simulating the steering resistance torque. The method includes sensing an actual angular velocity of the steering wheel, comparing the actual angular velocity with a threshold angular velocity, and calculating a magnetorheological torque signal based on the comparison. The method further includes determining an error signal based on the MR signal and a torque reference signal, and calculating a motor torque signal indicative of motor torque to be applied to the steering wheel. The method further includes applying torque generated by the MR device and the motor on the steering wheel.

Abstract: The present invention involves a system and method of simulating a steering resistance torque on a vehicle steering wheel of a steer-by-wire system. The steer-by-wire system uses a magnetorheological device and a motor to apply torque on the steering wheel for simulating the steering resistance torque. The method includes sensing an actual angular velocity of the steering wheel, comparing the actual angular velocity with a threshold angular velocity, and calculating a magnetorheological torque signal based on the comparison. The method further includes determining an error signal based on the MR signal and a torque reference signal, and calculating a motor torque signal indicative of motor torque to be applied to the steering wheel. The method further includes applying torque generated by the MR device and the motor on the steering wheel.

Abstract: A differential gear assembly including a differential housing and a ring gear mounted externally to the differential housing by a clamp. The differential housing and the ring gear each include an annular flange extending therefrom and the clamp includes a pocket which is adapted to receive the annular flanges therein. In another aspect, the flanges include opposing angled surfaces and the pocket includes opposing angled sides, whereby when the clamp is placed to the flanges, the angled surfaces of the flanges engage the angled sides of the clamp such that the clamp provides an axial clamping force to the flanges.

Abstract: A road wheel fuzzy logic control system, including a fuzzy logic control unit having, a plurality of inputs signals, and generating a control output signal, and a road wheel subsystem that receives the control output signal and generates an output feedback signal to the fuzzy logic control unit, wherein the fuzzy logic control tracks an input signal under the effects of uncertainties and disturbances from the road wheel subsystem and vehicle dynamics. The fuzzy logic control unit controls the effects of the uncertainty and disturbance and provides vehicle stability.

Abstract: One aspect of the present invention regards an automotive steering wheel control system having a steering wheel, a magnetorheological damper in communication with the steering wheel and a road wheel system operably connected to the magnetorheological damper where the magnetorheological damper controls the steering wheel in response to a signal from the road wheel system.

Abstract: A simulated steering feel system 10 is provided including a magneto-rheological fluid rotary resistance device 12. The magneto-rheological fluid rotary resistance device 12 is utilized to impart improved feedback, torque to a steering wheel 32.

Abstract: A torque-based method to steer a vehicle equipped with a steer by wire system begins when a driver applies torque to a steering wheel so as to change the direction in which the vehicle travels. Two sensors, a steering wheel angle sensor and a steering wheel torque sensor then generate an angle signal and a torque signal, respectively. In the unlikely event the vehicle steering system is malfunctioning, the steering wheel torque sensor will still generate a torque signal. This torque signal is used in place of the angle signal to generate the reference signal. Once the reference signal is generated, then it can be used to generate the road wheel angle signal, which is in turn used to position the road wheels accordingly.

Abstract: A system (10) and method for controlling a steer-by-wire steering system. The system (10) has a steering wheel control subsystem (12) that provides steering feel for the operator, a reference angle (40) to the road wheels and tracks the road wheel angle. A road wheel control subsystem (14) tracks a steering wheel angle and produces a steering wheel reference angle (32) and torque signal (34) to the steering wheel control subsystem (12). The system and method of the present invention implements the same steering requirements for a steer-by-wire steering system as a conventional steering system and can implement advanced and flexible steering functions that cannot be accomplished with a conventional steering system.

Abstract: A torque-based method to steer a vehicle equipped with a steer by wire system begins when a driver applies torque to a steering wheel so as to change the direction in which the vehicle travels. Two sensors, a steering wheel angle sensor and a steering wheel torque sensor then generate an angle signal and a torque signal, respectively. In the unlikely event the vehicle steering system is malfunctioning, the steering wheel torque sensor will still generate a torque signal. This torque signal is used in place of the angle signal to generate the reference signal. Once the reference signal is generated, then it can be used to generate the road wheel angle signal, which is in turn used to position the road wheels accordingly.

Abstract: A system (10) and method for controlling a steer-by-wire steering system. The system (10) has a steering wheel control subsystem (12) that provides steering feel for the operator, a reference angle (40) to the road wheels and tracks the road wheel angle. A road wheel control subsystem (14) tracks a steering wheel angle and produces a steering wheel reference angle (32) and torque signal (34) to the steering wheel control subsystem (12). The system and method of the present invention implements the same steering requirements for a steer-by-wire steering system as a conventional steering system and can implement advanced and flexible steering functions that cannot be accomplished with a conventional steering system.