Abstract: A rotational angle detection device includes: a main driving gear; two driven gears; two sensors that detect the respective rotational angles of the two driven gears; and a computation circuit configured to compute the rotational angle of the main driving gear based on the respective rotational angles of the two driven gears. The computation circuit includes a difference computation circuit and a wear detection circuit. The difference computation circuit is configured to compute a first difference. The wear detection circuit is configured to detect wear of the two driven gears through a comparison between a value of the first difference that is computed by the difference computation circuit and a first ideal value.

Abstract: A rotational angle detection device includes: a main driving gear; two driven gears; two sensors that detect the respective rotational angles of the two driven gears; and a computation circuit configured to compute the rotational angle of the main driving gear based on the respective rotational angles of the two driven gears. The computation circuit includes a difference computation circuit and a wear detection circuit. The difference computation circuit is configured to compute a first difference. The wear detection circuit is configured to detect wear of the two driven gears through a comparison between a value of the first difference that is computed by the difference computation circuit and a first ideal value.

Abstract: Provided is a sensor system capable of more accurately detecting abnormality. A sensor IC includes a first detector, a second detector, and a communication circuit. The first detector and the second detector output a first digital value and a second digital value according to the strength of a magnetic flux applied thereto, respectively. The communication circuit transmits the first and second digital values received from the first and second detectors to a control device. At this time, the communication circuitplaces the first and second digital values in a plurality of frames to transmit the plurality of frames. The communication circuit forms the plurality of frames such that bit information data of the first and second digital values placed in the frames is arranged in different orders between the first and second digital values.

Abstract: Provided is a sensor system capable of more accurately detecting abnormality. A sensor IC includes a first detector, a second detector, and a communication circuit. The first detector and the second detector output a first digital value and a second digital value according to the strength of a magnetic flux applied thereto, respectively. The communication circuit transmits the first and second digital values received from the first and second detectors to a control device. At this time, the communication circuit places the first and second digital values in a plurality of frames to transmit the plurality of frames. The communication circuit forms the plurality of frames such that bit information data of the first and second digital values placed in the frames is arranged in different orders between the first and second digital values.

Abstract: In an electric power steering system, an ECU calculates a steering angle of a steering wheel based on an output of a rotation angle sensor and an EPS gear ratio. The ECU calculates a correction amount for canceling a steering deviation caused due to a temperature change, based on a temperature of a rack shaft detected by a temperature sensor and a map stored in a memory, and corrects the correction amount by adding the correction amount to the calculated steering angle.

Abstract: A torque sensor to which a sensor device is applied includes: a first sensor IC that detects a torque that acts on a steering shaft of a vehicle and outputs detection signals based on the detection results; and a second sensor IC that detects a torque that acts on the steering shaft of the vehicle and outputs detection signals based on the detection results.

Abstract: In an electric power steering system, an ECU calculates a steering angle of a steering wheel based on an output of a rotation angle sensor and an EPS gear ratio. The ECU calculates a correction amount for canceling a steering deviation caused due to a temperature change, based on a temperature of a rack shaft detected by a temperature sensor and a map stored in a memory, and corrects the correction amount by adding the correction amount to the calculated steering angle.

Abstract: A resolver includes three resolver coils, which are arranged spaced apart in a circumferential direction of a rotor, and an excitation coil that generates a magnetic field to induce voltages in the resolver coils when receiving electric power. When the magnetic fields provided from the excitation coil to the three resolver coils are changed through rotation of the rotor, the voltages induced in the resolver coils are changed. This causes each of the three resolver coils to output three-phase signals having amplitude that changes in a sinusoidal manner with respect to the rotational angle of the rotor. The angular intervals between the corresponding adjacent pairs of the first to third resolver coils in the circumferential direction of the rotor are defined as first, second, and third division angles. Specifically, the first to third division angles are set to values different from one another.

Abstract: A torque sensor to which a sensor device is applied includes: a first sensor IC that detects a torque that acts on a steering shaft of a vehicle and outputs detection signals based on the detection results; and a second sensor IC that detects a torque that acts on the steering shaft of the vehicle and outputs detection signals based on the detection results.

Abstract: A resolver includes three resolver coils, which are arranged spaced apart in a circumferential direction of a rotor, and an excitation coil that generates a magnetic field to induce voltages in the resolver coils when receiving electric power. When the magnetic fields provided from the excitation coil to the three resolver coils are changed through rotation of the rotor, the voltages induced in the resolver coils are changed. This causes each of the three resolver coils to output three-phase signals having amplitude that changes in a sinusoidal manner with respect to the rotational angle of the rotor. The angular intervals between the corresponding adjacent pairs of the first to third resolver coils in the circumferential direction of the rotor are defined as first, second, and third division angles. Specifically, the first to third division angles are set to values different from one another.

Abstract: The electrically-powered steering apparatus obtains a steering torque and a steering angle within an allowable input range of those inputted into a first resolver and a second resolver based on a real zero point ? and further, a steering torque and a steering angle out of the allowable input range of those inputted to the first resolver and the second resolver based on (+) virtual zero point ? and (?) virtual zero point ?, which are set to a different value from the real zero point ?. Consequently, of the steering torques and steering angles inputted to the first resolver and the second resolver, the steering torque and steering angle out of the allowable input range impossible to obtain by the real zero point ? can be obtained based on the (+) virtual zero point ? and the (?) virtual zero point ?.

Abstract: This invention provides a resolver signal processing method and apparatus capable of enlarging an appropriate computation possible range and relaxing the installation accuracy of mechanical components which constitute a resolver and its surroundings. The electrically-powered steering apparatus obtains a steering torque and a steering angle within an allowable input range of those inputted into a first resolver and a second resolver based on a real zero point ? and further, a steering torque and a steering angle out of the allowable input range of those inputted to the first resolver and the second resolver based on (+) virtual zero point ? and (?) virtual zero point ?, which are set to a different value from the real zero point ?.