Correction apparatus for angle sensor, and angle sensor
AssigneeTDK Corporation
InventorShinichirou MOCHIZUKI
Life of this patent
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Abstract
An angle sensor generates an angle detection value based on a first and a second detection signal. A correction apparatus performs correction processing for generating a first corrected detection signal by adding a first correction value to the first detection signal and generating a second corrected detection signal by adding a second correction value to the second detection signal. When an angle to be detected varies with a period T and if no correction processing is performed, the angle detection value contains an Nth-order angle error component varying with a period of T/N. Each of the first and second detection signals contains an (N+1)th-order signal error component. The order of the first and second correction values is N−1.
Claims5
A correction apparatus for use with an angle sensor, the angle sensor including:
- a detection signal generator for generating a first detection signal and a second detection signal each having a correspondence with an angle to be detected;
- and an angle detector for generating an angle detection value based on the first and second detection signals, the angle detection value having a correspondence with the angle to be detected,
- the correction apparatus being configured to correct the first and second detection signals, and comprising:
- a correction processor configured to perform correction processing for generating a first corrected detection signal by adding a first correction value to the first detection signal and generating a second corrected detection signal by adding a second correction value to the second detection signal, wherein
- the first detection signal contains a first ideal component and a first signal error component,
- the second detection signal contains a second ideal component and a second signal error component,
- the first ideal component is expressed as A0 sin θ, the second ideal component is expressed as A0 cos θ, the first signal error component is expressed as −AH sin((N+1)θ+α), the second signal error component is expressed as −AH cos((N+1)θ+α), where θ represents the angle to be detected;
- N is an integer greater than or equal to 1;
- A0 and AH are real numbers other than 0;
- and α is a predetermined angle,
- the angle detection value without the correction processing being referred to as an uncorrected angle detection value θp, the uncorrected angle detection value θp contains an error, and when the angle θ to be detected varies with a predetermined period T, the error of the uncorrected angle detection value θp contains a component resulting from the first and second signal error components and varying with a period of T/N, and
- the first correction value is expressed as −AL sin((N−1)θp+α), and the second correction value is expressed as AL cos((N−1)θp+α), where AL is a real number such that |AH+AL| is less than |AH|.
Dependencies are inferred from the claim text.