An angle sensor comprising: a plurality of magnetic field sensing elements configured to detect a magnetic field and generate a respective plurality of analog magnetic field signals; a plurality of analog frontend circuits each analog frontend circuit associated with a respective magnetic field sensing element; and a digital feedback circuit configured to generate digital magnetic field signals from the plurality of analog magnetic field signals and generate digital error correction values, wherein the plurality of analog frontend circuits are configured to obtain the digital error correction values from the digital feedback circuit, generate analog correction values from the digital error correction values, and apply the analog correction values to the plurality of analog magnetic field signals to generate a plurality of corrected analog magnetic field signals.

A method for compensating a road line includes deriving a length of a left road line and a length of a right road line, recognized by a sensor, and determining a left road line level and a right road line level based on the length of the left road line and the length of the right road line; correcting the left road line level and the right road line level based on a change in the lengths of the left road line and the right road line or a change in curvatures of the left road line and the right road line; calculating a correction coefficient based on the corrected left road line level and the corrected right road line level; and correcting, by the correction coefficient, information about a road line with a lower level of the corrected left road line level and the corrected right road line level.

A magnetic field sensor apparatus includes a sensor signal generator generating a sensor signal responsive to a magnetic field. A switching level provider provides during a power up mode a switching level based on a most recently updated valid one of a first and a second value of a default switching level. If an update triggering condition occurs, the not most recently updated one of the first and second values of the default switching level is updated and the most recently updated one of the first and second values of the default switching level is maintained unchanged until a next update triggering condition occurs, so that the first and second values of the default switching level are updated alternately on consecutive triggering conditions.

An automatic correction method, for an encoder system for reading periodic signals on a scale as “SIN” and “COS” signals and converting the periodic signals into position signals, includes performing feedback to the “SIN” or “COS” signal to reduce an interpolation error after the conversion.

According to some embodiments, a method implemented in electronic circuitry includes: receiving a first signal having a sinusoidal waveform; receiving a second signal having a sinusoidal waveform; generating a composite signal responsive to the first and second signals; determining an orthogonality adjustment coefficient based on a duty cycle of the composite signal; and applying the orthogonality adjustment coefficient to generate an adjusted second signal that is substantially orthogonal to the first signal.

A method for calibrating a position measurement system includes receiving measurement data from the position measurement system and determining that the measurement data includes periodic distortion data. The position measurement system includes a nonius track and a master track. The method also includes modifying the measurement data by decomposing the periodic distortion data into periodic components and removing the periodic components from the measurement data.

A method for use in a sensor, comprising: generating a signal that is indicative of an angular position of a rotating target, the signal being generated by at least one magnetic field sensing element; adjusting the signal to produce an adjusted signal, the signal being adjusted based on a current value of a first adjustment coefficient; generating an output signal based on the adjusted signal; and updating the first adjustment coefficient, the updating including replacing the current value of the first adjustment coefficient with a new value of the first adjustment coefficient, the updating being performed by minimizing a function that is based on the current value of the first adjustment coefficient.

A sensor device includes a first sensor arrangement configured to generate first sensor signals based on sensing a varying magnetic field generated by a pole wheel having a pole wheel pitch, wherein the first sensor signals represent a first differential signal that defines a first measurement value; a second sensor arrangement configured to generate at least one second sensor signal based on sensing the varying magnetic field, wherein the at least one second sensor signal defines a second measurement value that is phase shifted from the first measurement value; and a signal processor configured to detect the pole wheel pitch based on the first measurement value and the second measurement value, and adjust a gain setting of an amplifier circuit based on the detected pole wheel pitch, where the amplifier circuit is configured to amplify the at least one second sensor signal.

Implementations of a resolver sensor system may include a signal amplifier portion configured to be coupled to a magnetoresistive sensor coupled with a movable element where the signal amplifier portion configured to receive a sine signal and a cosine signal from the magnetoresistive sensor; and a sensor offset canceling portion coupled with a signal amplifier portion. The sensor offset canceling portion may be configured to generate a direct current offset correction signal to the signal amplifier portion which uses two or more amplifiers included in the signal amplifier portion to receive the sine signal and the cosine signal and to generate corresponding adjusted digital sine and cosine signals. The signal amplifier portion may be configured to provide the adjusted digital sine signal and the adjusted digital cosine signal to one of the servo signal processor or the system controller for use in determining a position of the movable element.

There has been a problem that a rotation second-order angle error due to a phase difference between a sine signal and a cosine signal deviating from π/2 cannot be reduced. Therefore, provided is an angle detection device that can suppress a second-order angle error caused due to the phase difference between a first sine signal and a second sine signal deviating from π/2, by calculating a detection angle from a first detection signal based on the sum of two sine signals having different phases and a second detection signal based on the difference of the two sine signals.