Vertical gradiometric angle sensor, system and method

Abstract

Embodiments relate to magnetic field sensors, such as gradiometric magnetic field angle sensors with generally on-axis arrangements of sensor elements relative to a rotation axis of a magnet. In one embodiment, an angle sensor is arranged on-axis with respect to the rotation axis of a magnet that generates a magnetic field that can be detected by the angle sensor and analyzed to determine an angular position of the magnet. The sensor can comprise a plurality of sensor elements, such as two sensor elements, arranged on a substrate or die in a sensor package. As it rotates, the magnet generates a magnetic field, such as an inhomogenous magnetic field having a component perpendicular to the rotation axis and acting on the angle sensor. The plurality of sensor elements can detect this and other components, for example as a gradiometric sensor in which each element senses at least one component at its respective location, and the signals from the elements are compared to estimate or determine an angular position or degree of movement of the magnet.

Description

technical field [0001] The present invention relates generally to magnetic field sensors, and more particularly to gradiometric magnetic field angle sensors that sample at least two gradients of a magnetic field component on an axis of rotation, where the magnetic field component is substantially perpendicular to the axis of rotation . Background technique [0002] Magnetic field sensors can be used to sense the angle of rotation of a shaft or other object. For example, a magnet may be mounted on the shaft member, and a magnetic field sensor may be placed in close proximity to the magnet to sense the magnetic field induced by the magnet as it rotates with the shaft member. When a magnetic field sensor is mounted next to or adjacent to a rotating shaft member (ie, offset from the axis of rotation of the rotating shaft member), the sensor is often referred to as an "off-axis" magnetic field angle sensor. Off-axis magnetic field angle sensors are typically implemented where t...

AI Technical Summary

Problems solved by technology

Many conventional methods use more powerful and therefore more expensive magnets, which is another disadvantage when cost is considered

Also, without precise control of assembly tolerances, the accuracy of many conventional magnetic field angle sensors can be degraded

Another disadvantage of many conventional on-axis magnetic field angle sensors is the error caused by the background magnetic field

In general, there are a number of disadvantages associated with conventional magnetic field angle sensors

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