Vehicle wheel speed and acceleration sensor and method for calculating the same
AssigneeSAE Magnetics (H.K.) Ltd.
InventorMingGao Yao
Life of this patent
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Abstract
Systems and/or methods for detecting a rotating wheel's speed and/or acceleration are provided. A sensor is attached to the rotating wheel. The sensor includes a circuit (e.g. a Wheatstone bridge circuit) having a plurality of resistors (e.g. 4 resistors). Each resistor includes a giant magnetoresistance (GMR) element and has a resistance changeable based at least in part on a change in magnetic field intensity with respect to an external magnetic field. The sensor generates a signal based at least in part on the resistors' resistances. A processor is operable to calculate the rotating wheel's speed and/or acceleration based at least in part on the signal.
Claims12
A system for detecting a rotating wheel's speed and/or acceleration, comprising:
- a sensor attached to the rotating wheel, the sensor including a circuit having a plurality of resistors, each resistor having a resistance changeable based at least in part on a change in magnetic field intensity with respect to an external magnetic field which is substantially independent of any magnetic field generated by the rotating wheel or any elements collocated with the rotating wheel, the sensor being operable to generate a signal based at least in part on the resistors' resistances;
- and,
- a processor, operable to calculate the rotating wheel's speed and/or acceleration based at least in part on the signal,
- wherein the sensor is configured to operate substantially independent of any magnetic auxiliary fields, and
- wherein the external magnetic field is the earth's magnetic field.
A method for calculating a rotating wheel's speed and/or acceleration, the method comprising:
- locating on the rotating wheel a sensor with a circuit including a plurality of resistors,
- each resistor having a resistance changeable based at least in part on a chance in magnetic field intensity;
- converting to resistances changes in magnetic field intensities with respect to an external magnetic field which is substantially independent of any magnetic field generated by the rotating wheel or any elements collocated with the rotating wheel as indicated at least in part by elements in the resistors;
- generating a signal based on the resistances;
- and,
- calculating the rotating wheel's speed and/or acceleration based at least in part on the signal,
- wherein the sensor is configured to operate substantially independent of any magnetic auxiliary fields, and
- wherein the external magnetic field is the earth's magnetic field.
Dependencies are inferred from the claim text.