Magnetoelastic torque sensor that more accurately measures magnetic field change
First Claim
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1. A magnetoelastic torque sensor, comprising:
- a shaft that is magnetized in a first axial section in a first circumferential direction, and to which a torque to be measured can be applied;
wherein the shaft has a second axial section that is magnetized in a second circumferential direction that is opposed to the first circumferential direction;
a first magnetic field sensor disposed outside of the shaft, the first magnetic field sensor configured to record a magnetic field which is generated by the first section of the shaft and which is dependent on the applied torque;
wherein the first magnetic field sensor comprises a first 3D-Anisotropic MagnetoResistance (3D-AMR) sensor;
,a second magnetic field sensor disposed outside of the shaft, the second magnetic field sensor configured to record a second magnetic field which is generated by the second section of the shaft and which depends on the applied torque;
wherein the second magnetic field sensor comprises a second 3D-AMR sensor;
an evaluation circuit configured to;
receive sensor signals from the first 3D-AMR sensor;
determine a torque applied to the shaft based on the received sensor signals; and
compensate measurement value deviations due to a rotational asymmetry of the magnetized sections of the shaft during a rotation of the shaft around its longitudinal axis.
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Abstract
The magnetoelastic torque sensor includes a shaft that is magnetized in a first axial section in a first circumferential direction and to which a torque to be measured can be applied; a first magnetic field sensor outside of the shaft for recording a magnetic field, which is generated by the first section of the shaft and independent of the applied torque. The first magnetic field sensor comprises a first 3D Anisotropic MagnetoResistance (3D-AMR) sensor.
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Citations
12 Claims
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1. A magnetoelastic torque sensor, comprising:
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a shaft that is magnetized in a first axial section in a first circumferential direction, and to which a torque to be measured can be applied;
wherein the shaft has a second axial section that is magnetized in a second circumferential direction that is opposed to the first circumferential direction;a first magnetic field sensor disposed outside of the shaft, the first magnetic field sensor configured to record a magnetic field which is generated by the first section of the shaft and which is dependent on the applied torque;
wherein the first magnetic field sensor comprises a first 3D-Anisotropic MagnetoResistance (3D-AMR) sensor;
,a second magnetic field sensor disposed outside of the shaft, the second magnetic field sensor configured to record a second magnetic field which is generated by the second section of the shaft and which depends on the applied torque;
wherein the second magnetic field sensor comprises a second 3D-AMR sensor;an evaluation circuit configured to; receive sensor signals from the first 3D-AMR sensor; determine a torque applied to the shaft based on the received sensor signals; and compensate measurement value deviations due to a rotational asymmetry of the magnetized sections of the shaft during a rotation of the shaft around its longitudinal axis. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A device, comprising:
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a magnetoelastic torque sensor, the magnetoelastic torque sensor comprising; a shaft that is magnetized in a first axial section in a first circumferential direction, and to which a torque to be measured can be applied;
wherein the shaft has a second axial section that is magnetized in a second circumferential direction that is opposed to the first circumferential direction;a first magnetic field sensor disposed outside of the shaft, the first magnetic field sensor configured to record a magnetic field which is generated by the first section of the shaft and which is dependent on the applied torque;
wherein the first magnetic field sensor comprises a first 3D-Anisotropic MagnetoResistance (3D-AMR) sensor;a second magnetic field sensor disposed outside of the shaft, the second magnetic field sensor configured to record a second magnetic field which is generated by the second section of the shaft and which depends on the applied torque;
wherein the second magnetic field sensor comprises a second 3D-AMR sensor;an evaluation circuit configured to; receive sensor signals from the first 3D-AMR sensor; determine a torque applied to the shaft based on the received sensor signals; and compensate measurement value deviations due to a rotational asymmetry of the magnetized sections of the shaft during a rotation of the shaft around its longitudinal axis; and wherein the device is a bottom bracket of a bicycle or an e-bike, a motor, a motor test facility, a test facility for high-speed shafts with over 10,000rpm, a gearbox, a robot, an extruder, a straightening machine, a plane, an actuator, a cardan shaft, or a drive shaft.
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10. A method for determining a torque applied to a shaft, wherein the shaft is magnetized in a first axial section in a first circumferential direction;
- wherein the shaft has a second axial section that is magnetized in a second circumferential direction that is opposed to the first circumferential direction; and
wherein a first 3D Anisotropic MagnetoResistance (3D-AMR) sensor and a second 3D-AMR sensor are provided, the method comprising;applying a torque to the shaft; recording, via the first 3D-AMR sensor, a magnetic field generated by the first section of the shaft; recording, via the second 3D-AMR sensor, a second magnetic field generated by the second section of the shaft; determining the applied torque based on the magnetic field recorded by the first 3D-AMR sensor and the magnetic field recorded by the second 3D-AMR sensor; receiving sensor signals from the first 3D-AMR sensor; determining a torque applied to the shaft based on the received sensor signals; and compensating measurement value deviations due to a rotational asymmetry of the magnetized sections of the shaft during a rotation of the shaft around its longitudinal axis. - View Dependent Claims (11, 12)
- wherein the shaft has a second axial section that is magnetized in a second circumferential direction that is opposed to the first circumferential direction; and
Specification