Non-contact position sensor
View Patent ↗A non-contact position sensor having improved rotational angle measuring accuracy is provided. A magnet is attached To a rotating shaft. An angle sensor element detects magnetic field changes generated from the magnet due to rotation of the rotating shaft. A signal processor, on the basis of a temperature detected by a temperature sensor, corrects variance between the sensors including the sensor element, the signal processor, and the magnet by correcting an amplitude value and/or an offset value of a signal or variance due to time of the amplitude value. The sensor element 1 outputs the first and second outputs v 1 and v 2 and the signal processor obtains the temperature coefficients of the amplitude values of the output v 1 and output v 2 , or the temperature coefficients of the offset values, or the coefficients of variance due to time of the amplitude values, obtains the ratio of the first and second outputs corrected by these coefficients, and calculates the angle using the corrected ratio.
1. A non-contact position sensor comprising:
a magnetic field generation means rotating together with a rotating shaft;
a sensor element for sensing magnetic field changes generated from said magnetic field generation means due to said rotation of said rotating shaft;
signal processing means for processing an output signal of said sensor element to measure the rotational angle of said rotating shaft on the basis of the output signal; and
correction means for correcting variance among sensors including said sensor element, said signal processing means, and said magnetic field generation elements; wherein,
said sensor element outputs first and second outputs v 1 and v 2 ; and
said correction means obtains temperature coefficients of amplitude values of said output v 1 and said output v 2 , or temperature coefficients of offset values, or coefficients of variance due to time of said amplitude values, obtains a ratio of said first and second outputs corrected by said coefficients, and calculates an angle using said corrected ratio.
2. A non-contact position sensor comprising:
a magnetic field generation element that rotates together with a rotating shaft;
a sensor element for sensing magnetic field changes generated from said magnetic field generation element due to rotation of said rotating shaft;
signal processing means for processing an output signal of said sensor element to measure the rotational angle of said rotating shaft on the basis of the output signal; and
correction means for correcting variance among sensors including said sensor element, said signal processing means, and said magnetic field generation elements;
wherein,
the output of said sensor element includes two sine waves having a mutual phase difference,
said sensor element outputs first and second outputs v 1 and v 2 ; and
said correction means obtains temperature coefficients of amplitude values of said output v 1 and said output v 2 , or temperature coefficients of offset values, or coefficients of variance due to time of said amplitude values, obtains a ratio of said first and second outputs corrected by said coefficients, and calculates an angle using said corrected ratio.