Heterogeneous magnetic and inductive sensors
AssigneeAllegro MicroSystems, LLC
InventorsEmanuele Andrea Casu, Yannick Vuillermet, Andreas P. Friedrich
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Abstract
A heterogeneous sensor system includes a magnetic field sensor and an inductive sensor. A checker is configured to receive the magnetic field sensor output signal and the inductive sensor output signal and determine whether an error has occurred based on a comparison of the magnetic field sensor output signal and the inductive sensor output signal. Targets include at least a portion that is conductive and may include a ferromagnetic portion for back biased magnetic sensing. Additional features include on axis and off axis positioning of the sensors with respect to the target, multi-track targets for absolute position sensing, angle sensing and torque sensing configurations.
Claims14
An angle sensor system configured to sense an angle of a target that is rotatable about an axis of rotation, comprising:
- a magnetic field sensor, comprising a magnetic field sensing element responsive to a magnetic field affected by movement of the target, and configured to generate a magnetic field sensor output signal indicative of an angle of the target;
- an inductive sensor comprising:
- an oscillator configured to generate an oscillation signal;
- a primary coil coupled to receive the oscillation signal;
- and
- one or more secondary coils electromagnetically coupled to the primary coil as a function of the angle of the target, wherein the inductive sensor is configured to generate an inductive sensor output signal indicative of the angle of the target;
- and
- a checker configured to receive the magnetic field sensor output signal and the inductive sensor output signal and determine whether an error has occurred based on a comparison of the magnetic field sensor output signal and the inductive sensor output signal.
A method for sensing an angle of a target that is rotatable about an axis of rotation, comprising:
- generating a magnetic field sensor output signal with a magnetic field sensor comprising a magnetic field sensing element responsive to a magnetic field affected by movement of the target;
- generating an inductive sensor output signal with an inductive sensor comprising an oscillator configured to generate an oscillation signal, a primary coil coupled to receive the oscillation signal, and one or more secondary coils electromagnetically coupled to the primary coil as a function of the angle of the target;
- and
- comparing the magnetic field sensor output signal to the inductive sensor output signal to determine whether an error has occurred based whether a result of the comparison is within a predetermined range.
Dependencies are inferred from the claim text.