Systems and methods for detecting magnetic turn counter errors are provided herein. In one aspect, there is provided a magnetic field turn sensor system including: a magnetic field angle sensor, a signal processing path configured to receive an output from the magnetic field angle sensor and generate an angle measurement based on the output, a turn count path configured to process the output from the magnetic field angle sensor and output a quadrant measurement based on the output and a processor. The processor is configured to: receive the angle measurement from the signal processing path and the quadrant measurement from the turn count path, determine that the angle measurement deviates from the expected transition angle by more than a threshold value, and indicate a fault in response to determining that the angle measurement deviates from the expected transition angle by more than the threshold value.

An angle sensor temperature correcting device includes: a zero correcting factor storing portion that stores, as a reference temperature bridge midpoint potential difference offset and a bridge total resistance indicating value, a difference from an actual correct value, for a relative angle between a bridge circuit and a magnetic field, for the bridge midpoint potential difference, and a value indicating the total resistance of the bridge circuit, at a reference temperature, and stores, as a zero correcting factor, a ratio of the bridge midpoint potential difference offset and the bridge total resistance indicating value at the reference temperature; and a temperature correcting portion that performs temperature correction on angle information obtained from the bridge midpoint potential difference of the bridge circuit at a given time, based on a zero correcting factor stored in the zero correcting factor storing portion.

Methods and apparatus for processing a signal comprise at least one circuit configured to generate a measured signal during a measured time period and a reference signal during a reference time period. Also included is at least one dual- or multi-path analog-to-digital converter comprising at least a first processing circuit configured to process the measured signal, at least a second processing circuit configured to process the reference signal, and a third processing circuit configured to process both the measured signal and the reference signal.

A magnetic field sensor arrangement includes a magnetic field sensor element configured to provide a sensor output signal responsive to a magnetic field, wherein the sensor output signal is representative of a magnetic field amplitude; a processing module configured to provide a processed sensor output signal representative of the sensor output signal; a switching level calculation module configured to calculate a switching level, (1) during a power up mode, based on a default switching level, and (2) during a running mode, based on the processed sensor output signal; a comparator module configured to compare the processed sensor output signal with the switching level, and to provide a comparator output signal based on the comparison; and a storage module configured to store the default switching level, provide the default switching level during the power up mode, and update the default switching level during the running mode.

A rotation angle detection device for accurately detecting a rotation angle is obtained even when electromagnetic noise due to an electrical component(s) and the like of an electric automotive vehicle is superimposed on detection signals of the rotation angle detection device. The device includes a multi-phase/two-phase transformation unit for converting a plurality of detection signals, each being outputted from rotation detectors in accordance with a rotation angle of a rotating body so as to output transformed signals as two-phase signals; an addition-subtraction calculation unit for generating addition-subtraction signals by mutually performing addition to the two-phase signals and subtraction therefrom; an amplitude correction unit for modifying amplitudes of the addition-subtraction signals in accordance with an amplitude correction value, and for outputting post-correction addition-subtraction signals; and an angle calculation unit for calculating an angle based on the post-correction addition-subtraction signals, and for outputting an angular signal.

An interpolated position of an incremental encoder is provided. A first signal and a second signal having a quadrature relationship are received from the incremental encoder. A coarse position of the incremental encoder at a first time is produced using the quadrature relationship between the first signal and the second signal. An arcsine or arccosine value based on the first signal at the first time is determined using a lookup table and a fine position of the incremental encoder is calculated using the determined value. The interpolated position of the incremental encoder, based on both the coarse position and the fine position, is then provided.

A magnetic field sensor uses upper and lower thresholds. The upper and lower thresholds are limited such that they have a minimum separation distance between equivalent voltage levels of the upper and lower thresholds.

Systems and methods for detecting magnetic turn counter errors are provided herein. In one aspect, there is provided a magnetic field turn sensor system including: a magnetic field angle sensor, a signal processing path configured to receive an output from the magnetic field angle sensor and generate an angle measurement based on the output, a turn count path configured to process the output from the magnetic field angle sensor and output a quadrant measurement based on the output and a processor. The processor is configured to: receive the angle measurement from the signal processing path and the quadrant measurement from the turn count path, determine that the angle measurement deviates from the expected transition angle by more than a threshold value, and indicate a fault in response to determining that the angle measurement deviates from the expected transition angle by more than the threshold value.

The present disclosure describes a two-stage method for estimating an angle offset of an angle sensor in a system comprising a permanent-magnet synchronous motor. An initial value for the estimated angle offset is first determined with a short circuit test. Next, a torque of the motor may be controlled so that the motor is maintained at a zero speed. Minor adjustments are made to the value of the angle offset to find a minimum magnitude of stator current. A value at which the stator current is at its minimum is used as a final angle offset.

A method and an apparatus for determining a rotation angle of a rotor in a motor with the aid of angle sensors by measurement of reference values and correction of the effected computations. The method is used, for example, in a synchronous motor.