A method of measuring a rotational position of an assembly with circumferential ferromagnetic teeth includes applying an excitation signal for a cycle to an actuator, the cycle causing a first rotational displacement of a first ferromagnetic tooth from a first rotational position to a second rotational position and a second rotational displacement of a second ferromagnetic tooth from the second rotational position to a third rotational position. The method further includes measuring a plurality of first signal outputs from a magnetoresistive sensor during the cycle; determining one or more signal offset values based on the plurality of first signal outputs; applying the signal excitation for a portion of a second cycle to the actuator; measuring second signal outputs from the magnetoresistive sensor; generating corrected signals by modifying the second signal outputs with the signal offset values; and, based on the corrected signals, determining a rotational position of the assembly.

Provided is a rotation angle detection device including: a coefficient identification unit configured to identify, based on a sine signal and a cosine signal which are based on a rotation angle of a rotating body, coefficients of frequency components included in the sine signal and the cosine signal; a correction value calculation unit; and a rotation angle calculation unit. The coefficient identification unit is configured to identify, for each of integers M and N which satisfy a relationship in which M+N is equal to a positive constant, and each of which is equal to or larger than 0, a coefficient of each of (M+N−1)th order components included in the sine signal and the cosine signal, based on results of application of low-pass filters to products of an M-th power of the sine signal and an N-th power of the cosine signal.

Methods and systems for providing rotary position sensor information. One system includes an electronic processor configured to receive a first set of signals from a first bridge circuit of a rotary position sensor and receive a second set of signals from a second bridge circuit of the rotary position sensor. In response to the receipt of the first set of signals from the first bridge circuit stopping, the electronic processor is also configured to identify a fault associated with the first bridge circuit. The electronic processor is also configured to receive a pulse signal and determine a rotary angle based on the pulse signal and the second set of signals from the second bridge circuit. The electronic processor is configured to generate an output torque value based on the rotary angle for controlling a motor.

A method of operating an intermittently measuring or pulsed incremental position sensor, and a position sensor that has noise detecting circuitry activated during each measurement, triggering corrective measurements as long as the influence of noise is detected. Corrective measurements immediately follow and replace a noise-influenced measurement well before the next scheduled measurement. Noise can be detected as a differential amplifier's common-mode input signal, thus clearly separating the influence of noise from the sensor's differential input signal.

In an absolute encoder, a system of linear equations is built based on the mathematical analysis that each phase-delayed displacement signal from a plurality of position sensors placed at certain electrical phase angle positions in a 360° electrical cycle contains a component of its two orthogonal displacement signals, sin(θ) and cos(θ). The two orthogonal displacement signals are optimally obtained by solving the system of linear equations based on the principle that the sum of all other tap's signals other than own tap's signal is forced to be zero at each tap, which is essentially applying the zero-force (ZF) equalization to the phase-delayed sinusoidal or square wave displacement signals of position sensors. By applying the ZF equalization to distortion-prone raw signals of a plurality of position sensors, signal components, other than the two orthogonal displacement signals, are eliminated and distortion-minimized optimal two orthogonal displacement signals are synthesized.

In an absolute encoder, a system of linear equations is built based on the mathematical analysis that each phase-delayed displacement signal from a plurality of position sensors placed at certain electrical phase angle positions in a 360° electrical cycle contains a component of its two orthogonal displacement signals, sin(θ) and cos(θ). The two orthogonal displacement signals are optimally obtained by solving the system of linear equations based on the principle that the sum of all other tap's signals other than own tap's signal is forced to be zero at each tap, which is essentially applying the zero-force (ZF) equalization to the phase-delayed sinusoidal or square wave displacement signals of position sensors. By applying the ZF equalization to distortion-prone raw signals of a plurality of position sensors, signal components, other than the two orthogonal displacement signals, are eliminated and distortion-minimized optimal two orthogonal displacement signals are synthesized.

A magnetic sensor detects presence or absence of a magnetic field and its polarity. South pole and north pole magnetic fields are respectively detected by the south pole detection operation and the north pole detection operation. A signal processing circuit of the magnetic sensor performs a unit operation including at least one of the south pole detection operation and the north pole detection operation repeatedly at an interval. In this case, if the south pole is detected in the i-th unit operation, the south pole detection operation is performed first in the (i+1)th unit operation. If the south pole is detected in the south pole detection operation, the north pole detection operation is not performed in the unit operation. If the north pole is detected in the i-th unit operation, operations are performed oppositely to the above.

A monitoring control device for diagnosing a presence/absence of a detection failure of a rotation state of a rotator includes: a rotation sensor that detects the rotation state of the rotator and outputs an analog signal in response to the detected rotation state; a converter that calculates a first absolute angle of the rotator at a first timing based on the analog signal and outputs a signal including the first absolute angle; a first control device 10 that obtains the first absolute angle; and a second control device 20 that calculates a second absolute angle of the rotator at a second timing different from the first timing based on the analog signal. The first control device 10 generates a first diagnostic signal based on the first absolute angle, and outputs the first diagnostic signal to the second control device. The second control device generates a second diagnostic signal based on the second absolute angle, and compares the first diagnostic signal with the second diagnostic signal to diagnose the presence/absence of the detection failure of the rotation state.

A sensor device comprises a sensor unit for generating a signal indicative of a physical quantity. The device comprises a processing unit for receiving the signal, in which the processing unit comprises a storage memory for storing data derived from the signal as provided by the sensor unit at at least two points in time. The device comprises a bus interface for communicating with an electronic control unit via a digital communication bus. When a read command is received from the electronic control unit, an estimate of the physical quantity is sent in response to the electronic control unit. The processing unit comprises an estimator for calculating the estimate at a reference point in time based on the data stored in the storage memory, in which the reference point in time differs from the point in time at which the read command is received by substantially a predetermined offset.

An apparatus for determining an item of position information relating to a position of a magnetic field transducer relative to a position sensor. The position sensor is designed to generate at least one periodic measurement signal when the magnetic field transducer moves relative to the position sensor. A processing unit of the apparatus is designed to determine the position information based on a respective measurement signal value of a respective periodic measurement signal using a calibration function assigned to the respective periodic measurement signal. The assigned calibration function represents the respective periodic measurement signal using a Fourier series having a respective plurality of Fourier coefficients which differ from zero and are of an order greater than zero. The processing unit is designed to at least approximately solve the assigned calibration function for the respective measurement signal value in order to determine the position information.