Abstract: A traction control system for a fourwheel drive vehicle having a center differential comprises a brake pressure control apparatus, an engine output control apparatus, a differential limiting torque control apparatus, vehicle speed calculating means for calculating a reference vehicle speed of a vehicle, slip amount calculating means for calculating a slip amount of each wheel, target slip amount determining means for determining a front target slip amount of front wheels and a rear target slip amount of rear wheels, traction control determining means for determining to operate a traction control when the slip amount of the front wheels exceeds the front target slip amount or when the slip amount of the rear wheels exceeds the rear target slip amount, brake pressure calculating means for calculating a brake pressure so as to apply a brake to the wheels and engine output calculating means for calculating a target engine torque corresponding to a difference between the slip amount and the target slip amount, whe

Abstract: A tire inflation pressure sensor mounted on the outside of the wheel. The sensor housing includes a diaphragm, a cylinder, a magnet holder, a spring, a magnet holding member connected with a magnet, a guide member and a stopper. When the inflation pressure of a tire is normal, the magnet holding member stops at a position where the magnet indicates a north pole. When the inflation pressure goes down below a specified value, the magnet holding member travels a predetermined distance and at the same time the magnet holding member rotates at a predetermined angle indicating a south pole. This changeover of magnetic polarity is detected by an external magnetic induction element to operate a warning device.

Abstract: A motor control system controls a steering apparatus with an electric motor. A command signal is generated in accordance with a torsion torque of the steering apparatus and the rotational direction and torque of the electric motor is controlled in accordance with the command signal. The system includes a vehicle speed sensor, a hysteresis circuit for changing a hysteresis width in accordance with an output from the vehicle speed sensor, and a phase compensation designating section responsive to an output from the torsion torque sensor supplied via the hysteresis circuit for outputting a command signal corresponding to a change rate of the torsion torque, so that the rotation direction and torque of the electric motor is controlled in accordance with the command signal. The hysteresis circuit makes large the hysteresis width during a high speed running of a vehicle to avoid influence of external disturbance due to vibrations from roads.

Abstract: A method for detecting abnormal condition of a torque sensor in an electric power steering system in which a power of an electric motor assisting steering operation of a vehicle is supplied in response to a torque signal generated from the torque sensor, the method comprising the steps of detecting a condition where the torque signal generated from the torque sensor is substantially equal to zero, detecting another condition wherein the rate of changing steering angle is larger than a predetermiend value, while the steering angle is held in an increasing state, and further detecting that the above detected conditions last more than a predetermined period.

Abstract: An active suspension system of an automotive vehicle having four air suspension units for four wheels has a first sensor for detecting vertical acceleration of the mass above each suspension unit spring, a second sensor for detecting the vertical relative displacement of the masses above and below each unit spring, a controller for operating in response to the output signals from the two sensors and a relative displacement velocity signal obtained by differentiation of the signal from the second sensor to generate an instruction air flow quantity signal, and a control valve operating in response to this flow quantity signal from each controller to control the charging or discharging of air into or from each unit. An auxiliary damper is provided in each unit to damp vibrations of relatively high frequencies.

Abstract: A method for detecting an absolute steering angle of a steering angle sensor such as encoder for a vehicle wherein the steering angle sensor generates an output signal indicating a relative rotation angle of a steering shaft of the vehicle and at least one reference signal representing a reference position for every one rotation of the steering shaft. The method comprises the steps of setting a deviation .DELTA..theta. between the reference position and an actual straight-ahead driving state position responsive to the output signal and the reference signal, storing the deviation .DELTA..theta. in a memory of a computer which holds the deviation .DELTA..theta. while the computer is disconnected from a battery, determining a steering angle with the reference position responsive to the output signal and the reference signal, and correcting by the deviation .DELTA..theta. the steering angle to obtain the absolute steering angle.

Abstract: A motor control apparatus for an electric power steering system having a torsion torque sensor for detecting a torsion torque of the steering system of a vehicle, a command signal generating unit for generating a command signal in accordance with the torsion torque detected by the torque sensor, and a motor control unit for driving and controlling a motor of the electric power steering system in accordance with the command signal. The improvement of this invention is to assist steering force within the steering wheel correcting range. A steering speed detecting unit is provided for detecting the steering speed. The output signal from the steering speed range detecting unit is supplied to the steering wheel correction command unit which generates an assist correction signal. The assist correction signal has a characteristic that the absolute value thereof takes a predetermined value when a small steering angle range is detected.

Abstract: A method for detecting abnormal condition of a torque sensor in an electric power steering system in which a power of an electric motor assisting steering operation of a vehicle is supplied in response to a torque signal generated from the torque sensor, the method comprising the steps of detecting a condition where the torque signal generated from the torque sensor is substantially equal to zero, detecting another condition wherein the rate of changing steering angle is larger than a predetermined value, while the steering angle is held in an increasing state, and further detecting that the above detected conditions last more than a predetermined period.

Abstract: An electric power steering system for an automobile which includes a steering shaft having a steering torque transmitting shaft. The electric power steering system includes a housing mounted on the steering torque transmitting shaft, a torsion torque sensor, in the housing, for detecting a torsion torque in the steering shaft during a steering operation to generate a torsion torque signal representing the detected torsion torque, and a controlling unit for providing a drive signal, in response to the torsion torque signal, to control an electric motor, mounted to the housing and operatively connected to the steering torque transmitting shaft, for reducing a steering effort. The controlling unit is integrally mounted to the housing.

Abstract: There are disclosed a device and method for saving power supply of a steering sensor for a vehicle having a conventional circuit for detecting a steering angle and a supplementary circuit for detecting an amount of steering angle change when an ignition switch is turned off. The conventional circuit comprises a rotary encoder for generating two signals of sine waveform-like having a phase discrepancy of 90 degrees responsive to a rotation of a steering shaft, and a microcomputer for calculating an absolute angle from the sine waveform-like signals. The supplementary circuit comprises a waveform shaping circuit for converting the sine signals into two rectangular wave pulse signals. While the switch is turned on, the circuit continues to detect the absolute angle based on the sine waves. When the switch is turned off, the supplementary circuit counts and hold the change amount of the angle as the pulse signals while the circuit maintains the storage of the last absolute angle.

Abstract: Power assist of steering wheel by an electric motor is carried out by the sum of an assist motor current generated based on the output of a torsion torque sensor and a compensating current generated in dependency on the variation rate of the output of the torsion torque sensor. An assist torque current correction circuit controls the compensating current such that the amount of the compensating current is reduced in accordance with an increase in steering angle of the steering system.

Abstract: A motor control apparatus for an electric power steering system of a vehicle is provided. The apparatus includes a torsion torque sensor for detecting a torsion torque of the steering system, a vehicle speed sensor, a steering angle sensor, a control unit for controlling the rotational direction and torque of an electric motor in accordance with a command signal derived from the outputs from the torque sensor, vehicle speed sensor and steering angle sensor, and a neutral position recovery command unit for generating a recovery signal in response to which the steering system is returned to a neutral position, in accordance with an output signal from the steering angle sensor and when the absolute values of the output signals from the torsion torque sensor and vehicle speed sensor becomes smaller than or equal to predetermined values.

Abstract: An active suspension of a motor vehicle is controlled by a system and a method which comprise combining a controller and an actual flow quantity estimation circuit for estimating by logic operation the flow quantity of the fluid actually flowing through each control valve of the suspension with respect to a total desired flow quantity, and calculating the difference between the actual flow quantity value thus estimated and the desired flow quantity, thereby correcting the desired flow quantity. A command signals is generated and transmitted in accordance with the desired flow quantity thus corrected for operating the control valve to undergo opening/closing operation.

Abstract: A system having a motor operatively connected to a steering system for reducing the steering effort. The system is provided with a torsion torque sensor provided for detecting torsion torque generated in the steering system in a steering operation, and a steering angle sensor provided for detecting steering angle. In response to the output signal of the torsion torque sensor, an assist signal is produced, and in response to the output of the steering angle sensor, a damping signal dependent on the steering speed of a steering wheel is produced. The damping signal is increased with an increase of vehicle speed. A corrected damping signal is added to the assist signal, thereby damping movement of the steering wheel.

Abstract: A hydraulic power steering system is disclosed which has a steering control valve operatively connected to a steering shaft to be actuated by the torsional torque exerted thereon by a steering wheel, and a hydraulic cylinder operated by the control valve for assisting the steering of the vehicle. An electric motor drive unit is coupled to the steering shaft for exerting torque thereto in a direction for returning the steering wheel to a straight ahead position. An electronic control circuit is connected to the motor drive unit for exerting a variable amount of return torque to the steering shaft according to the steering angle of the steering shaft, or to both the steering angle and the travelling speed of the vehicle.

Abstract: A system having a motor operatively connected to a steering system for reducing the steering effort. The system is provided with a torsion torque sensor provided for detecting torsion torque generating in the steering system in steering operation. In response to the output signal of the torsion torque sensor, an assist signal is produced. The system has a dead zone for the output signal of the torsion torque sensor. Only when the output signal exceeds the dead zone, the assist signal is produced to operate the motor.

Abstract: A system having a motor operatively connected to a steering system for reducing the steering effort. The system is provided with a torsion torque sensor provided for detecting torsion torque generating in the steering system in steering operation. In response to the output signal of the torsion torque sensor, an assist signal is produced. A return torque signal dependent on the lateral acceleration exerted on a motor vehicle is generated. The return torque signal is added to the assist signal, thereby operating the motor to return a steering wheel.

Abstract: A system having a motor operatively connected to a steering system for reducing the steering effort. The system is provided with a torsion torque sensor provided for detecting torsion torque generating in the steering system in steering operation. In response to the output signal of the torsion torque sensor, an assist signal and an auxiliary assist signal are produced. A detector is provided for detecting whether a variation value of the torsion torque is in an increasing direction or in a decreasing direction and for producing a direction signal dependent on the detected direction. When a direction signal representing the variation value of the torsion torque in the decreasing direction is generated, the auxiliary assist signal is reduced in value, thereby reducing a total assist signal of the assist signal and the auxiliary assist signal.

Abstract: An electric power steering system has a torsion torque sensor provided for detecting torsion torque generating in a steering system of a motor vehicle, for providing an assist signal for driving a motor to turn a steering wheel. A steering angle sensor is provided for detecting steering angle of the steering wheel and for producing a steering angle signal. In response to the steering angle signal, a return torque signal is produced for steering wheel. A vehicle speed sensor is provided for producing a vehicle speed signal dependent on speed of the vehicle, and a calculator is provided calculating lateral acceleration impared to the vehicle and for producing a lateral-acceleration-dependent-return torque signal. In accordance with the vehicle speed signal, the lateral-acceleration-dependent-return torque signal is corrected to produce return torque correcting signal, the absolute value of which reduces with increase of vehicle speed.

Abstract: An electrically operated power steering device connected to a steering system of a motor vehicle to provide supplementary steering power by means of an electric motor. A motor control unit for the electrically operated power steering device controls the rotational direction and output torque of the electric motor by the sum of an assistance signal based on the signal from a torsional torque sensor and a velocity sensor in the steering system, a restoration signal based on the output signal from a steering angle sensor, and an auxiliary assistance signal based on the output signal from the torsional torque sensor in the steering system as a command signal.