Patent ID: 11867504
Assignee: TDK CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 5:
6. A signal generation method for generating a first corrected detection signal and a second corrected detection signal by using a first detection signal and a second detection signal each having a correspondence with a rotating magnetic field,
the first detection signal containing a first ideal component and a first signal error component, the second detection signal containing a second ideal component and a second signal error component, the first ideal component being expressed as A0 sin θ, the second ideal component being expressed as A0 cos θ, the first signal error component being expressed as −AH sin((N+1)θ+α), the second signal error component being expressed as −AH cos((N+1)θ+α), where θ represents an angle that a direction of the rotating magnetic field at a reference position forms with respect to a reference direction in a reference plane, and that has a correspondence with a rotating field angle; 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, wherein
the signal generation method comprises:
generating a first corrected detection signal by adding a first correction value to the first detection signal, the first correction value being expressed as −AL sin((N−1)θp+α), where AL is a real number such that |AH+AL| is less than |AH|, θp is an uncorrected angle, the uncorrected angle θp is a calculated value of the angle θ calculated by using the first and second detection signals, the uncorrected angle θp contains an error, and when the angle θ varies with a predetermined period T, the error of the uncorrected angle θp contains a component resulting from the first and second signal error components and varying with a period of T/N; and
generating a second corrected detection signal by adding a second correction value to the second detection signal, the second correction value being expressed as AL cos((N−1)θp+α).