A speed detection device includes a comparator module, a sensor lead with a node connected to the comparator module, and a limit set module. The limit set module is connected to the sensor lead node and to the comparator by an upper limit lead and a lower limit lead to provide upper and lower limits to the comparator that vary according to amplitude variation in voltage applied to the sensor lead.

A speed sensor for detecting a speed of a magnetizable object. The speed sensor (100) can be supplied with an electric alternating signal with a first frequency by an electric signal source. The speed sensor including: a primary coil for generating a magnetic alternating field with the first frequency; first and second secondary coils. The first and second secondary coils can each be magnetically coupled to the primary coil via a magnetizable object. First and second electric signals induced in the first and second secondary coils respectively by the generated magnetic alternating field; a Goertzel filter bank detects first and second amplitude values of respective spectral components of the induced first and second electric signals in the event of a second frequency which differs from the first frequency. A processor determines the speed of the magnetizable object depending on the detected first amplitude value and the detected second amplitude value.

Examples described herein provide a rotary system that includes a rotor having an axis of rotation, a position sensor to measure an angular position of the rotor with respect to the axis of rotation, and a processing system to perform operations. The operations include receiving an output from the position sensor, the output being a measure of an angular position of the rotor with respect to the axis of rotation. The operations further include generating, based on the output from the position sensor, an error signal, an estimated angular velocity, and an estimated position. The operations further include performing a position sensor harmonic adaptation based at least in part on the error signal, the estimated angular velocity, and the estimated position to generate adaptation coefficients. The operations further include performing a position sensor harmonic compensation based on the adaptation coefficients and the estimated position to generate a difference in position.

A rotor assembly for deployment within a momentum control device that enables near-zero revolutions per minute (RPM) sensing, and method for making same, are provided. The provided rotor assembly utilizes a magnet coupled to the rotor shaft and a stationary sensor element to detect magnetic flux from the magnet and derive reliable near zero RPM therefrom.

Embodiments relate to sensors, such as speed sensors and angle sensors, that use a modulated supply voltage to approximately double output signals of the sensors because the sensor element and the supply voltage exhibit the same frequency. In embodiments, the sensor element is an xMR element, and the modulated supply voltage is generated on-chip, such as by another xMR element. Direct frequency doubling of the output signal of the sensor element therefore can be obtained without additional and complex circuitry or signal processing.

Embodiments relate to sensors, such as speed sensors and angle sensors, that use a modulated supply voltage to approximately double output signals of the sensors because the sensor element and the supply voltage exhibit the same frequency. In embodiments, the sensor element is an xMR element, and the modulated supply voltage is generated on-chip, such as by another xMR element. Direct frequency doubling of the output signal of the sensor element therefore can be obtained without additional and complex circuitry or signal processing.

A method of determining an angle by an encoder includes generating a first angle data based on a rotation of a bipolar magnet and a second angle data based on a rotation of the multipolar magnet; determining a first waveform signal based on the first angle data and a second waveform signal based on the second angle data; converting the first waveform signal into a third waveform signal having a cycle similar to the second waveform signal; calculating an angle result value as a function of the second angle data and a determined value about a location of a rotation cycle of the multipolar magnet based on a difference between the second waveform signal and the third waveform signal; and determining an absolute angle corresponding to the calculated angle result value based on stored angle data.

An assembly has a rotating element, a sensor, and an evaluation unit; wherein the element has a number a of markings; wherein the markings pass through a region detected by the sensor in cycles when the element rotates; wherein the sensor is configured to send a signal to the evaluation unit; and wherein the evaluation unit is configured to assign a time t.sub.i for when each signal is sent, wherein the evaluation unit is configured to calculate a function m(t) over time t as a measure for a gradient of the rotational rate of the element.

A method for detecting a loosened bolted wheel joint on a wheel of a vehicle. The angular velocity of a hub of the wheel is evaluated. A periodic wheel modulation of the angular velocity is ascertained. An oscillation of the wheel generated due to the loosened bolted wheel joint is detected, using a step-change in a phase angle of the modulation by an expected angular increment, which is a function of the number of bolts.

A sensor for measuring a rotation speed of a magnetic encoder includes a first magnetic detector detecting a magnetic field induced from the magnetic encoder and outputting a strength value of the magnetic field as a first electrical signal, a second magnetic detector detecting the magnetic field induced from the magnetic encoder and outputting a strength value of the magnetic field as a second electrical signal, a first output signal generator for generating and outputting first rotation data including information indicating a rotation speed of a wheel based on the first electrical signal, and a second output signal generator configured to generate second rotation data including information indicating a rotation speed of the wheel based on the second electrical signal. The information indicating the rotation speed in the second rotation data may have a higher resolution than the information indicating the rotation speed in the first rotation data.