A magnetic sensor system may include a first magnetic sensor and a second magnetic sensor. The first magnetic sensor may include a first triplet of sensor elements for measuring a magnetic field. The first triplet of sensor elements may be aligned linearly along a direction of movement. A first pair of differential signals, output by the first magnetic sensor, may indicate a position of the magnetic sensor system, along the direction of movement, relative to a magnetic pole pair. The second magnetic sensor may include a second triplet of sensor elements for measuring the magnetic field. The second triplet of sensor elements may be aligned linearly along the direction of movement. The second magnetic sensor may be positioned relative to the first magnetic sensor such that a second pair of differential signals, output by the second magnetic sensor, indicates a position of the magnetic sensor system across multiple pole pairs.

A position sensor system for determining a position of a sensor device relative to a magnetic structure, the system comprising: said magnetic structure comprising a plurality of non-equidistant poles; said sensor device comprising at least three magnetic sensors spaced apart over predefined distances; and the sensor device being adapted for: a) measuring at least three in-plane magnetic field components, and for calculating two in-plane field gradients therefrom; b) measuring at least three out-of-plane magnetic field components, and for calculating two out-of-plane field gradients therefrom; c) calculating a coarse signal based on these gradients; d) calculating a fine signal based on these gradients; e) determining said position based on the coarse signal and the fine signal.

A system is provided with a magnetic field sensor being positioned in a magnetic field of a magnet that is coupled to a rotatable driving shaft. The magnetic field sensor is configured to sense a rotation of the magnetic field in response to a rotation of the rotatable driving shaft, and generate an angle sensor signal based on an orientation angle of the magnetic field. The angle sensor signal includes angular values that represent an absolute orientation angle of the rotatable driving shaft. The system includes a memory storing a mapping of values of a patterned signal to the angular values, electronic circuitry configured to generate, based on the angular values and the stored mapping, the patterned signal, and a signal generator circuit configured to generate a signal representing the absolute orientation angle of the rotatable driving shaft based on the angle sensor signal.

A system is provided with a magnetic field sensor being positioned in a magnetic field of a magnet that is coupled to a rotatable driving shaft. The magnetic field sensor is configured to sense a rotation of the magnetic field in response to a rotation of the rotatable driving shaft, and generate an angle sensor signal based on an orientation angle of the magnetic field. The angle sensor signal includes angular values that represent an absolute orientation angle of the rotatable driving shaft. The system includes a memory storing a mapping of values of a patterned signal to the angular values, electronic circuitry configured to generate, based on the angular values and the stored mapping, the patterned signal, and a signal generator circuit configured to generate a signal representing the absolute orientation angle of the rotatable driving shaft based on the angle sensor signal.

A magnetic field sensor includes a plurality of magnetic field sensing elements operable to generate magnetic field signals indicative of a magnetic field associated with an object, a plurality of channels coupled to receive the magnetic field signals and configured to generate a respective plurality of phase separated channel signals, and an output circuit coupled to receive the plurality of phase separated channel signals and configured to generate a sensor output signal including distinguishable pulses associated with the plurality of phase separated channel signals. The sensor output signal may include a first plurality of pulses associated with a first one of the phase separated channel signals and having a first characteristic and a second plurality of pulses associated with a second one of the phase separated channel signals and having a second characteristic different than the first characteristic, such as different signals levels and/or different pulse widths.

A monitoring system for monitoring one or more properties associated with a rotating shaft is provided. The system includes a first phonic wheel which is mounted coaxially to the shaft for rotation therewith, the first phonic wheel comprising a circumferential row of teeth. The system further includes a first sensor configured to detect the passage of the row of teeth of the first phonic wheel by generating a first alternating measurement signal. The system further includes a processor unit configured to determine the durations of successive first speed samples. Each first speed sample is a block of n successive cycles of the first alternating measurement signal, where n is an integer, and in which the beginning of each cycle is a zero-crossing point from the previous cycle and the end of each cycle is the corresponding zero-crossing point to the next cycle. At least one axial location of the first phonic wheel every m.sup.th tooth of the row of teeth of the first phonic wheel has a circumferential thickness which is different from that of the other teeth of the first phonic wheel, where m is an integer, mn, and m is neither a factor nor a multiple of n. When the first sensor is positioned at said axial location of the first phonic wheel and at any given rotational speed of the first phonic wheel, the durations of the successive first speed samples display a characteristic repeating pattern of longer and shorter sample durations relative to the average duration of the successive first speed samples. The amount by which the longer and shorter sample durations differ from the average duration is in proportion to the amount by which the circumferential thickness of the m.sup.th teeth differs from that of the other teeth at said axial location of the first phonic wheel. The processor unit monitors the properties associated with the rotating shaft from the characteristic repeating pattern.

By configuring an encoder scale as a varying scale with successively increasing or decreasing pitch, sensors in a travel path of the scale can detect a phase difference to determine an absolute position of the scale for use in an industrial control system. Due to the successively increasing or decreasing pitch, each sensor can detect successively increasing or decreasing properties (such as magnetic fields) from the scale in a uniquely identifiable pattern. By taking the difference between readings of adjacent sensors, each sensor detecting properties of the scale, an absolute position of the scale between the sensors can be determined. The principle for feedback for the encoder system is analogous to a Nonius or Vernier principle to determine absolute position.

A system is provided with a magnetic field sensor being positioned in a magnetic field of a magnet that is coupled to a rotatable driving shaft. The magnetic field sensor is configured to sense a rotation of the magnetic field in response to a rotation of the rotatable driving shaft, and generate an angle sensor signal based on an orientation angle of the magnetic field. The angle sensor signal includes angular values that represent an absolute orientation angle of the rotatable driving shaft. The system includes a memory storing a mapping of values of a patterned signal to the angular values, electronic circuitry configured to generate, based on the angular values and the stored mapping, the patterned signal, and a signal generator circuit configured to generate a signal representing the absolute orientation angle of the rotatable driving shaft based on the angle sensor signal.

A system is provided with a magnetic field sensor being positioned in a magnetic field of a magnet that is coupled to a rotatable driving shaft. The magnetic field sensor is configured to sense a rotation of the magnetic field in response to a rotation of the rotatable driving shaft, and generate an angle sensor signal based on an orientation angle of the magnetic field. The angle sensor signal includes angular values that represent an absolute orientation angle of the rotatable driving shaft. The system includes a memory storing a mapping of values of a patterned signal to the angular values, electronic circuitry configured to generate, based on the angular values and the stored mapping, the patterned signal, and a signal generator circuit configured to generate a signal representing the absolute orientation angle of the rotatable driving shaft based on the angle sensor signal.

A monitoring system for monitoring the axial position of a rotating shaft is provided. The system includes first and second, axially adjacent phonic wheels which are mounted coaxially to the shaft for rotation therewith. The first and second phonic wheels respectively have first and second circumferential rows of detectable features. The system further includes a sensor configured to detect the passage of the first row of detectable features by generating a first alternating measurement signal component, and to detect the passage of the second row of detectable features by generating a second alternating measurement signal component. The first and second rows of detectable features are configured such that the first and second alternating measurement signal components have distinguishably different frequencies and/or such that the first alternating measurement signal component generated by the sensor when the sensor is axially aligned with the first row has a distinguishably different amplitude to the second alternating measurement signal component generated by the sensor when the sensor is axially aligned with the second row. The sensor is positioned relative to the first and second phonic wheels such that axial displacement of the shaft causes the signal generated by sensor to contain less of the first alternating measurement signal component and more of the second alternating measurement signal component whereby the axial position of the shaft can be monitored.