Title:
SINE WAVE MEASURING DEVICE, ITS MEASURING METHOD, IMPEDANCE MEASURING DEVICE AND ROTATION ANGLE DETECTOR
Document Type and Number:
Japanese Patent JP3508718
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To accurately detect an amplitude of an input sine wave shaped signal by a simple composition.
SOLUTION: An analog signal including a sine wave signal Ax.sin(2πFt+ψ) of a frequency the same as a known reference analog sine wave signal A0.sin2πft is input in an input terminal IN. An analog-to-digital converter 130 samples the input analog signal at a predetermined rate and subjects it to an analog-to- digital conversion. A sine wave coefficient calculating part 140a and a cosine wave coefficient calculating part 140b respectively calculate coefficients Csin1 and Ccos1 of each basis function by applying methods of least squares respectively using a sine wave function sin2πft and a cosine wave function cos2πft as basis functions. An amplitude calculating part 150a calculates the amplitude Ax of the sine wave signal Ax.sin(2πft+ψ) by executing computing of (Csin12+ Ccos12)1/2. A phase calculating part 150b calculates a deviated amount ψ of a phase of the sine wave signal Ax.sin(2πft+ψ) by executing computing of tan-1(Csin1/Ccos1).
Inventors:
Nishihara, Akio
Application Number:
JP2000365470A
Publication Date:
March 22, 2004
Filing Date:
November 30, 2000
Export Citation:
Assignee:
TOYOTA MOTOR CORP
International Classes:
G01B7/30; G01B7/00; G01D5/244; G01D5/245; G01R19/04; G01R23/16; G01R25/00; G01R27/02; (IPC1-7): G01B7/30; G01D5/245
Attorney, Agent or Firm:
大庭 咲夫 （外１名）
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