There are arranged a sensor magnet fixed to a rotary shaft and configured to generate a magnetic field for detecting a rotation angle, and a plurality of sensors arranged so as to be opposed to the sensor magnet and each configured to output a sine signal and a cosine signal in accordance with the magnetic field. First and second sensors are arranged on two radial lines different from each other, respectively, out of three radial lines dividing a circumference about the rotary shaft of the sensor magnet into six equal parts. An angle calculation unit is configured to carry out calculation so that 3n-th (n is a natural number) order harmonic components out of odd-order harmonic components of each of the sine signal and the cosine signal output by the first and second sensors cancel one another, to thereby calculate the rotation angle.

When the state where steering torque detected by a torque detection unit is normal and the value of the steering torque is the same as or larger than a threshold value continues, an assist command generation unit that generates an assist command corresponding to steering torque produced by a driver limits the assist command; a failure determination unit includes a first failure determination unit that performs determination on a failure regardless of the limitation of the assist command and a second failure determination unit that performs determination on a failure while the assist command is limited, and stops driving of a motor when the second failure determination unit determines that there exists a failure.

The present disclosure relates to an apparatus for a non-contactive sensor having an ESD protection structure, and an apparatus for a non-contactive sensor having an ESD protection structure according to one embodiment of the present disclosure includes: a sensing member that acquires sense information emitted from a detection target object; a circuit board that is separately positioned below the sensing member and includes a sensor IC and one or more grounds; and an ESD protection element that is positioned on the circuit board and encloses a part of the sensor IC protruding on the circuit board.

A method and apparatus for detecting a failure of a current sensor measuring the magnitude of a current, by which a motor is driven. A required current calculator calculates a phase and a magnitude of a current required for a motor, in accordance with a torque required for the motor. An estimated current calculator calculates an estimated current, in accordance with the phase and the magnitude of the required current. A failure detector detects a failure of a current sensor by comparing the estimated current with a current measured by the current sensor.

An electric power steering system includes a control for providing a calculated torque assist demand in the event of failure of a steering wheel torque sensor. The control is responsive to one or more of a vehicle speed, a steering column position, a steering column velocity, a gear lever position, a vehicle yaw rate and a vehicle lateral acceleration for generating the calculated torque assist demand. The control is operable to modify the torque assist demand by providing one or more of (a) friction and inertial compensation, (b) vehicle oversteer compensation, (c) reverse motion compensation, (d) damping compensation and (e) self steer prevention.

Provided is a steering control apparatus in which the response of steering assistance to driver's steering can be improved during execution of rotation angle sensor-less control. When the rotation angle sensor-less control is executed and when an induced voltage value is equal to or lower than a threshold voltage, driving of a motor is controlled based on a second addition angle. The second addition angle is calculated such that values obtained by multiplying a first pre-addition angle calculated based on a steering torque and a second pre-addition angle calculated based on an induced voltage derivative by respective predetermined use ratios that are based on the induced voltage value are added together. By using the second addition angle, a more appropriate estimated electrical angle is calculated in response to a driver's steering situation.

An electric power assisted steering apparatus comprises an upper column shaft that in use is operatively connected to a steering wheel of the vehicle; and a lower column shaft that in use is operatively connected to the road wheels of the vehicle. A torsion bar interconnects the upper column shaft and the lower column shaft; and an electric motor is connected to the lower column shaft of the torque sensor assembly. A first torque signal generating means generates a first torque signal based on angular deflection of the torsion bar, and a second torque signal generating means generating a second torque signal based on angular deflection of the torsion bar, the apparatus further including: an error determining circuit which produces two error signals, each indicative of the validity of a respective torque signal, and a torque plausibility estimator which generates two plausibility signals each indicative of the plausibility of a respective one of the two torque signals, a torque channel selector that observes the value of the two error signals and the two plausibility signals and selects which, if any, of the torque signals are to be used in the generation of a control signal for the motor, and a motor control circuit which generates the control signal dependent on the values of the selected torque signal or torque signals.

A steering angle detection device is provided with a plurality of rotation angle sensors and a plurality of control units. The rotation angle sensors are capable of at least continuously calculating a rotation speed while an ignition switch of a vehicle is turned off, and are provided so as to correspond to steering angle calculation units which calculate steering angle based on the rotation speed and a rotation angle acquired from the rotation angle sensors and midpoint information related to the neutral position of a steering member. Power supplies are provided on a per-system basis. The rotation angle sensors or the control units are capable of holding the midpoint information while the ignition switch is turned off. If a power supply abnormality resulting in power supply failure occurs in some of the systems, the control unit of the abnormal system acquires the midpoint information and the rotation speed from the control unit of a normal system when the ignition switch is turned on.

The failure detection device includes: a failure detection unit configured to detect failure of a torque detection unit, the torque detection unit detecting torque applied to a rotary shaft with plural torque sensors; and a controller configured to control drive of a motor such that the motor outputs continuous torque in an event that the failure detection unit detects failure of the torque detection unit, the continuous torque continuously generating torque that is, if at least one of the plural torque sensors is working properly, detectable by the at least one of the plural torque sensors.

A power steering device includes a steering mechanism structured to steer a steerable wheel in accordance with steering of a steering wheel. A first sensor is structured to sense a specific state quantity of steering. A second sensor is structured to sense the specific state quantity. A first actuation part is structured to apply a steering force to the steering mechanism. A second actuation part is structured to apply a steering force to the steering mechanism. A first microprocessor is configured to receive an output signal from the first sensor, and control driving of the first actuation part based on the output signal received from the first sensor. A second microprocessor is configured to receive an output signal from the first sensor and an output signal from the second sensor, and control driving of the second actuation part based on the output signal received from the first sensor.