Abstract: A system and method for determining a position and or speed of a rotating shaft includes a target wheel for securement to a rotatable shaft, the target wheel including a plurality of North/South pole pairs, each pole of each North/South pole pairs being essentially the same size; and a sensor assembly. The sensor assembly includes a first magnetic sensor array for sensing the pole pairs to provide a cosine signal and a sine signal and a second magnetic sensor array for sensing the pole pairs to provide a cosine signal and a sine signal, wherein the second magnetic sensor array is disposed transverse to the first magnetic sensor array. An electronic processor is configured to receive inputs from the first magnetic sensor array and the second magnetic sensor array, and to determine a position and/or speed of the shaft.

Abstract: A system for determining an absolute position of a device includes a high resolution track, a sensor and processing unit associated with the high resolution track, a reference track having a plurality of pole pairs arranged to define a plurality of single-track Gray code segments, and an array of Hall effect sensors associated with the reference track to output a reference signal to the sensor and processing unit indicative of the coarse absolute position of the device over the Gray code segments. A third track has at least one pole pair. At least one sensor associated with the third track outputs a signal used to determine a location within one of the plurality of Gray code segments. The sensor and processing unit combines the third track signal, the reference signal, and the position of the device over the high resolution track to determine an initial, fine absolute position.

Abstract: A system for determining an absolute position of a device includes a high resolution track, a sensor and processing unit associated with the high resolution track, a reference track having a plurality of pole pairs arranged to define a plurality of single-track Gray code segments, and an array of Hall effect sensors associated with the reference track to output a reference signal to the sensor and processing unit indicative of the coarse absolute position of the device over the Gray code segments. A third track has at least one pole pair. At least one sensor associated with the third track outputs a signal used to determine a location within one of the plurality of Gray code segments. The sensor and processing unit combines the third track signal, the reference signal, and the position of the device over the high resolution track to determine an initial, fine absolute position.

Abstract: A system for determining an absolute position of a device includes a high resolution track (14), a sensor and processing unit (22) associated with the high resolution track (14), a reference track (18) having a plurality of pole pairs arranged to define a single-track Gray code segment, and an array of Hall effect sensors (26) associated with the reference track to output a reference signal to the sensor and processing unit indicative of the coarse absolute position of the device over the single-track Gray code segment. The sensor and processing unit (22) combines the reference signal with the position of the device over the high resolution track to determine an initial, fine absolute position of the device. An up/down hardware counter (34) increments the initial fine absolute position using a signal generated from the high resolution track, and without any further software-based processing, to maintain and continuously update the fine absolute position of the device.

Abstract: A sensor system including a movable member, a sensor, and an interpolator. The sensor is configured to generate a first output signal and a second output signal. The first output signal has a first phase angle, the second output signal has a second phase angle, and a first difference between the first phase angle and the second phase angle has a first value. The first value of the first difference includes an offset related to a mechanical incompatibility between the sensor and the movable member. The interpolator is configured to receive the first output signal and the second output signal. The interpolator is operable to apply a compensation factor to generate a third signal having a third phase. The compensation factor has a value that is based on the mechanical incompatibility between the sensor and the movable member.

Abstract: A method and apparatus for sensing magnetic field strength with a pair of Hall effect sensors includes sampling a sensed voltage for the Hall effect sensors during a first phase and combining the sensed voltage. During a second phase, obtaining sensed voltages for the Hall effect sensors and combining the sensed voltages. The sensed voltages from the first phase and the second phase are combined to obtain a summed voltage and remove the Hall effect sensor and amplifier offset error value. In one arrangement, the summed voltage corresponds to the sensed Hall voltage of the first Hall effect sensor added to the Hall voltage of the second Hall effect sensor. In another arrangement, the summed voltage corresponds to the sensed Hall voltage of the first Hall effect sensor subtracted by the sensed Hall voltage of the second Hall effect sensor. Changes in the summed voltage with respect to a reference voltage are counted to determine the speed of a rotating shaft having magnets or a similar arrangement.

Abstract: A system for determining an absolute position of a device includes a high resolution track (14), a sensor and processing unit (22) associated with the high resolution track (14), a reference track (18) having a plurality of pole pairs arranged to define a single-track Gray code segment, and an array of Hall effect sensors (26) associated with the reference track to output a reference signal to the sensor and processing unit indicative of the coarse absolute position of the device over the single-track Gray code segment. The sensor and processing unit (22) combines the reference signal with the position of the device over the high resolution track to determine an initial, fine absolute position of the device. An up/down hardware counter (34) increments the initial fine absolute position using a signal generated from the high resolution track, and without any further software-based processing, to maintain and continuously update the fine absolute position of the device.

Abstract: A sensor system including a clock generation module, a sensor, a conditioning module, and an output module. The clock generation module is configured to generate a modulation signal and an output sampling signal. The modulation signal has a modulation frequency, and the sampling signal has a sampling frequency. The sensor is configured to generate an output signal having an output value. The output signal is modulated by the modulation signal, and the output value includes a sensor output value and an offset value. The conditioning module is configured to receive the output signal, condition the output signal, and generate a conditioned output signal including the sensor output value and the offset value. The output module is configured to receive the conditioned output signal and the output sampling signal. The output sampling signal is operable to sample the conditioned output signal at a value that corresponds to the sensor output value.

Abstract: A method and apparatus for sensing magnetic field strength with a pair of Hall effect sensors includes sampling a sensed voltage for the Hall effect sensors during a first phase and combining the sensed voltage. During a second phase, obtaining sensed voltages for the Hall effect sensors and combining the sensed voltages. The sensed voltages from the first phase and the second phase are combined to obtain a summed voltage and remove the Hall effect sensor and amplifier offset error value. In one arrangement, the summed voltage corresponds to the sensed Hall voltage of the first Hall effect sensor added to the Hall voltage of the second Hall effect sensor. In another arrangement, the summed voltage corresponds to the sensed Hall voltage of the first Hall effect sensor subtracted by the sensed Hall voltage of the second Hall effect sensor. Changes in the summed voltage with respect to a reference voltage are counted to determine the speed of a rotating shaft having magnets or a similar arrangement.

Abstract: A sensor system including a movable member, a sensor, and an interpolator. The sensor is configured to generate a first output signal and a second output signal. The first output signal has a first phase angle, the second output signal has a second phase angle, and a first difference between the first phase angle and the second phase angle has a first value. The first value of the first difference includes an offset related to a mechanical incompatibility between the sensor and the movable member. The interpolator is configured to receive the first output signal and the second output signal. The interpolator is operable to apply a compensation factor to generate a third signal having a third phase. The compensation factor has a value that is based on the mechanical incompatibility between the sensor and the movable member.

Abstract: A sensor system including a clock generation module, a sensor, a conditioning module, and an output module. The clock generation module is configured to generate a modulation signal and an output sampling signal. The modulation signal has a modulation frequency, and the sampling signal has a sampling frequency. The sensor is configured to generate an output signal having an output value. The output signal is modulated by the modulation signal, and the output value includes a sensor output value and an offset value. The conditioning module is configured to receive the output signal, condition the output signal, and generate a conditioned output signal including the sensor output value and the offset value. The output module is configured to receive the conditioned output signal and the output sampling signal. The output sampling signal is operable to sample the conditioned output signal at a value that corresponds to the sensor output value.

Abstract: A sensor system for detecting at least one of a speed and a position of a rotatable member. The sensor system includes a high-resolution sensor circuit including a plurality of Hall effect sensors and at least one independent Hall effect sensor, wherein the independent Hall effect sensor includes at least one of a power supply line, a ground line, and an output line, none of which are connected to the high-resolution sensor circuit.

Abstract: A method of determining a position on a magnetic track of an encoder includes providing a group of magnetic pole pairs that forms a portion of the magnetic track, recording a relative position within a first magnetic pole pair in the group using a first magnetic sensor proximate a high-resolution portion of the magnetic track, detecting adjacent pole junctions within the group of magnetic pole pairs with a second magnetic sensor positioned proximate a reference portion of the magnetic track, correlating the adjacent pole junctions with the first magnetic pole pair to determine a relative position of the first magnetic pole pair within the group, and calculating a local absolute position within the group using the relative position within the first magnetic pole pair and the relative position of the first magnetic pole pair within the group.

Abstract: A method of determining a position on a magnetic track of an encoder includes providing a group of magnetic pole pairs that forms a portion of the magnetic track, recording a relative position within a first magnetic pole pair in the group using a first magnetic sensor proximate a high-resolution portion of the magnetic track, detecting adjacent pole junctions within the group of magnetic pole pairs with a second magnetic sensor positioned proximate a reference portion of the magnetic track, correlating the adjacent pole junctions with the first magnetic pole pair to determine a relative position of the first magnetic pole pair within the group, and calculating a local absolute position within the group using the relative position within the first magnetic pole pair and the relative position of the first magnetic pole pair within the group.

Abstract: A sensor system for detecting at least one of a speed and a position of a rotatable member. The sensor system includes a high-resolution sensor circuit including a plurality of Hall effect sensors and at least one independent Hall effect sensor, wherein the independent Hall effect sensor includes at least one of a power supply line, a ground line, and an output line, none of which are connected to the high-resolution sensor circuit.

Abstract: A sensor assembly includes a magnetic track having a plurality of magnetic poles separated by a plurality of pole junctions. The sensor assembly also includes a first magnetic sensor disposed proximate a high-resolution portion of the magnetic track and a second magnetic sensor disposed proximate a reference portion of the magnetic track. The second magnetic sensor spans adjacent pole junctions in the magnetic track. Each of the adjacent pole junctions includes a high-resolution segment corresponding with the high-resolution portion of the magnetic track and a reference segment corresponding with the reference portion of the magnetic track. The reference segment of each pole junction is one of offset and aligned with the corresponding high-resolution segment in each pole junction.

Abstract: A sensing apparatus includes first and second magnet assemblies. The first magnet assembly includes first and second magnets that have respective first and second opposite magnetic fields. The first magnet has a plurality of dimensions including an inner circumferential dimension, an outer circumferential dimension, an inner axial dimension, an outer axial dimension, and a radial dimension, and the second magnet has a corresponding plurality of dimensions. The inner circumferential dimension or outer circumferential dimension of the first magnet is relatively smaller than the corresponding dimension of the second magnet. A second magnet assembly is positioned at a distance from the first magnet assembly and includes a third magnet having a third magnetic field opposite to the first magnetic field. The first magnet assembly is a high-resolution track, and the second magnet assembly is a low-resolution track.

Abstract: A sensor assembly includes a magnetic track having a plurality of magnetic poles separated by a plurality of pole junctions. The sensor assembly also includes a first magnetic sensor disposed proximate a high-resolution portion of the magnetic track and a second magnetic sensor disposed proximate a reference portion of the magnetic track. The second magnetic sensor spans adjacent pole junctions in the magnetic track. Each of the adjacent pole junctions includes a high-resolution segment corresponding with the high-resolution portion of the magnetic track and a reference segment corresponding with the reference portion of the magnetic track. The reference segment of each pole junction is one of offset and aligned with the corresponding high-resolution segment in each pole junction.

Abstract: A system for determining an absolute position of a motor. The system includes first and second multi-polar magnetic rings, first and second processing units, and at least one external sensor. The first multi-polar magnetic ring is concentrically positioned around the motor, and has a plurality of pole pairs. The second multi-polar magnetic ring is concentrically positioned around the first multi-polar magnetic ring, and has at least one pole pair. The first processing unit is positioned near the first multi-polar magnetic ring to determine an angular position over one of the pole pairs of the first multi-polar magnetic ring. The sensor is positioned external to the processing unit and over the second multi-polar magnetic ring to indicate a state of the pole pair of the second multi-polar magnetic ring. The second processing unit generates an absolute position of the motor based on the angular position and the state.

Abstract: A sensing apparatus includes high and low-resolution tracks, and a compensation track. The low-resolution track includes a first magnet that has a first magnetic field. The high-resolution track is spaced apart from the low-resolution track by a first gap and includes a second magnet and a third magnet. The second magnet has a second magnetic field that is substantially identical to the first magnetic field, and the third magnet has a third magnetic field that is substantially opposite to the first magnetic field. The compensation track is spaced apart from the high-resolution track by a second gap and includes a fourth magnet having a fourth magnetic field that is substantially opposite to the first magnetic field and configured to reduce a magnetic field from the first magnet that is superimposed on the second and third magnets.