Shaft angle measurement

摘要

A magnetic angle sensor system for determining a shaft angle for one or more pivoting or rotating shaft means. The or each of said shaft means is provided with means adapted to generate a magnetic field, such that means can be energised in turn to induce a magnetic field in a detector. In a first step the sensor arrangement measures the background field in the absence of any current in the wire or solenoid, such that the angle of the shaft means can be determined from the magnetic field in the solenoid and the background field. The invention concerns the use of an evoked response field whether alternating or steady whereby the angle is determined by the difference in field when the evoking magnetic stimulus is present from when it is absent.

主权项

1. A magnetic angle sensor system for determining a shaft angle comprising at least one pivotable shaft pivotable about a Z-axis, wherein:
a. said pivotable shaft is provided with a magnetic field generator configured to create a magnetic field; b. said pivotable shaft is provided with a magnetic sensor able to measure a component of said magnetic field lying along an X-axis that is perpendicular to said Z-axis and a component of said magnetic field lying along a Y-axis that is perpendicular to said X-axis and said Z-axis; c. said pivotable shaft is provided with a distorting component configured to pivot with said pivotable shaft, said distorting component configured to distort said magnetic field so that said magnetic field is non-symmetric with respect to said Z-axis; d. said magnetic sensor measures a background field in the absence of any current in said magnetic field generator, and said magnetic sensor measures a magnetic field in the presence of a current in said magnetic field generator, such that said shaft angle of said pivotable shaft can be determined from a difference between said measurement in the presence of a current in said magnetic field generator and said measurement in the absence of a current in said magnetic field generator.