Abstract: A failure detection system for detecting an operational failure of a rack and pinion type of hydraulically controlled power steering system which employs a power cylinder to assist the driver in manipulating front wheels of the vehicle by utilizing hydraulic pressure applied to a steering gear connected to the front wheels utilizes a pressure switch for detecting a specified level of oil pressure provided by the power cylinder to be at operational failure when the vehicle speed remains higher than a specified speed for a specified time period, the pressure switch detects the specified level of hydraulic pressure.

Abstract: A power steering control apparatus for a motor vehicle which ensures an appropriate steering force conforming to the prevailing road condition and hence the safety for the motor vehicle even when the wheels are locked due to hard brake applied on a slippery road. The apparatus includes a first microcomputer for determining a driving torque of a steering assist motor on the basis of steering torque information generated upon steering of a steering wheel and pseudo vehicle speed information to thereby generate and output a driving signal for the steering assist motor on the basis of the driving torque, and a second microcomputer for generating the pseudo vehicle speed signal on the basis of wheel rotation speed signals and acceleration/deceleration signal of the motor vehicle to thereby generate and output a brake actuation signal for wheels of the motor vehicle on the basis of the pseudo vehicle speed signal, the acceleration/deceleration information and brake application information.

Abstract: A motor-driven power steering system for a vehicle and a method for controlling the same in which the assisting torque of a motor is transmitted through a clutch toward steerable road wheels of the vehicle for power assisting the steering motion imparted to a steering wheel by an operator. It is possible to precisely judge whether there exists a failure in the operation of the motor and/or the clutch before the clutch is connected. To this end, a certain characteristic value of the motor under no load condition is measured with the clutch disconnected, and then compared with a preset comparison value such as a reference motor current to determine whether the motor is mechanically restricted. If not, the clutch is connected. If so, the clutch is kept not connected so that an appropriate failsafe operation can be performed.

Abstract: A vehicle control apparatus includes a steering torque sensor (1) for sensing a steering torque, a motor (3) for generating a steering assisting force, a CPU (22) for determining a motor drive direction based on at least the steering force and a motor drive direction restricting circuit (25) for restricting the drive direction of the motor (3) determined by the CPU (22) based on a steering force determination level as a motor drive direction determination criterion and the steering force, and the steering force determination level is changeable.

Abstract: A monitoring process of a subordinate CPU executes a monitoring subroutine based on external data to check if a main CPU is operating properly or not. A ROM stores test input data for the monitoring subroutine and reference data that should be obtained by the monitoring subroutine based on the test input data. The subordinate CPU alternately executes the monitoring process and a logic determination process which executes the monitoring subroutine based on the test input data. When the monitoring subroutine gives results different from the reference data, the logic determination process determines that there is an abnormality in the monitoring subroutine.

Abstract: Disclosed is a rear wheel neutralizing system for a four-wheel steering vehicle, including an actuator for returning rear wheels to their neutral positions; a potentiometer for detecting a returning displacement to the neutral position of the wheel; a motor for operating the actuator; a vehicle speed sensor for detecting vehicle speeds; and an electronic control unit for determining whether the four-wheel steering system is malfunctioning and for operating the motor while receiving a signal from the vehicle speed sensor. The rear wheel neutralizing system further comprises an encoder for detecting the angular velocity of the motor and transmitting a signal on the angular velocity to the electronic control unit.

Abstract: A shaft position indicator in which a collar is formed on and moves on in accordance with a shaft. The collar is placed opposite an optical sensor and includes a notch which activates an optical sensor when the notch is located opposite the sensor. When the notch is opposite the sensor, a driving circuit outputs a voltage. When the notch is not opposite the sensor, the driving circuit outputs 0 voltage. The light source and sensor are placed a distance from the collar equal to the focal length to substantially eliminate interference from ambient light.

Abstract: A control apparatus for a motor-driven power steering system of a motor vehicle controls the steering system such that a steering torque required to be applied by a driver is prevented from increasing abruptly or steeply even when generation of an assist torque applied to the steering system for assisting the driver in steering operation is to be stopped.

Abstract: An electric power steering apparatus includes a judgment unit which passes a judgment that a condition, in which an offset signal indicative of the offset between a target current signal and a motor current signal, or a drive control signal used for controlling an electric motor is greater than a threshold, has continued for an allowable time. Based on this judgment, a forced drive control unit forcibly drives the electric motor. A fault judgment unit monitors the motor current in all times and judges a current detecting unit to be at fault if the motor current does not vary even though the electric motor is drive forcibly. Thus, even when a failure in the current detecting unit occurs during movement of a motor vehicle, such failure can reliably be detected. Additionally, since the judgment is performed after the electric motor is driven forcibly, misjudgment does not occur even when the judgement at the judgment unit results from continuous application of abrupt manual steering operation.

Abstract: A reaction force actuator 3 for giving reaction force to a steering wheel 2 disengaged from a steering mechanism 1 is provided. A steering control unit 4 is provided to control so that the reaction force decided in accordance with the detected results of the running speed by a vehicle speed sensor 6 and the detected results of a road surface condition by a current sensor 7a, an open air temperature sensor 7b, a wiper switch 7c and a supersonic wave sensor 7d. Also, the steering motor 5 for applying the steering force to the steering mechanism 1 is operated smaller at higher speed and larger at slower speed at running by the operation of the steering control unit 4 in accordance with the detected results of the running speed by the vehicle speed sensor 6. Therefore, the same steering feelings as those of the coupling type steering system are obtained to realize a steering system enabling the reliable steering operation to effect under the various different running conditions.

Abstract: One central processing unit 63 is connected to the other central processing unit 64 via a communication line 200. Various data, such as driving operational information, actuation commands, and driving conditional information, are exchanged and compared between two central processing units 63 and 64 through a communication line 200. If any disagreement is found in the comparison result, a current supply circuit 65 stops supplying current to a driving motor 1.

Abstract: In a controller of an electric power steering apparatus for use with an automotive vehicle, a regenerating condition determining section determines whether or not a motor of the vehicle is in a regenerating condition, and a regeneration control signal generating section generates a regeneration control signal to control the regenerating condition of the motor. A switching section selects between the motor control signal and the regeneration control signal in accordance with a result of determination by the regenerating condition determining section. With this arrangement, a motor current including a regenerative current that is caused to flow in the motor in response to a vehicle driver effecting during-stoppage steering maneuvering and then releasing a steering wheel can be controlled independently of a feedback loop of the controller.

Abstract: A power steering motor control unit for driving a motor in a PWM mode with feedback motor current control reduces fluctuations in the output torque of the motor caused by switching among a plurality of motor driving modes or a change in the duty value of the PWM signal. The control unit as a switching device driving circuit for driving the motor in the PWM mode and a plurality of motor driving modes for the driving control system of a motor, Q/D switching circuitry 14 for switching the motor driving mode, and detected current correcting circuitry 16 for correcting at least one input signal of an input signal comparing circuit provided in a feedback control loop in accordance with the motor driving mode. When the motor driving mode is switched, the correction value given by the detected current correcting circuitry is changed.

Abstract: The invention provides an electric power steering apparatus in which a duty ratio upper limit value is obtained on the basis of a vehicle speed of a vehicle and a supply voltage for a motor and a target duty ratio is determined as a value not exceeding the duty ratio upper limit value, so as to prevent an excessive steering assisting force from being caused by the malfunction of a driving current detecting circuit for the motor.