Revolution indicator and a program for the revolution indicator

• US 7,890,271 B2
• Filed: 11/02/2007
• Issued: 02/15/2011
• Est. Priority Date: 11/07/2006
• Status: Expired due to Fees

• Current Assignee: ONO SOKKI (Thailand) Co. Ltd.
• Original Assignee: ONO SOKKI (Thailand) Co. Ltd.
• Inventors: Miyano, Tomio, Hori, Hideaki
• Primary Examiner(s): Wachsman; Hal D
• Assistant Examiner(s): Suarez; Felix E
• Application Number:
  US11/982,602
• Publication Number:
  US 20080106256A1
• Time in Patent Office: 1,201 Days
• Field of Search: 702/33, 702/56, 702/85, 702/148, 702/180, 702/184, 702/185, 736/60, 318/490, 324/177
• US Class Current: 702/33
• CPC Class Codes: G01P 3/44 for measuring angular speed G01P3/56 takes precedence
• CPC Class Codes: G01P 3/48 by measuring frequency of generated current or voltage in general G01R23/00

Abstract

The object of the invention is providing a revolution indicator and a program for the indicator, which can detect a varying number of revolutions precisely. The indicator includes: a detecting portion detecting a physical phenomenon resulting from the revolution movement of a measuring object; a FFT computation portion performing a fast Fourier transform of the data detected by the detecting portion under a specific data length, and computing and outputting the analytical data; and a revolution computing portion computing the number of revolutions of the measuring object based on the analytical data output from the FFT computation portion. A variation determination portion is equipped, which makes the FFT computation portion compute the first analytical data continuously, based on the data successively detected by the detecting portion under the first data length and determines whether there is any variation or not in the first analytical data computed continuously.

Claims

1. A revolution indicator, comprising:

a detecting portion which detects data related to a physical phenomenon resulting from the revolving movement of a measuring object;

a fast Fourier transformation computation portion which performs a fast Fourier transform of the data detected by the detecting portion under a first data length to compute first analytical data, and outputs the first analytical data; and

a revolution computing portion which computes the number of revolutions of the measuring object; and

a variation determination portion which is equipped to make the fast Fourier transformation computation portion compute a plurality of the first analytical data continuously based on the data successively detected by the detecting portion under the first data length and to determine whether there is variation or not among the plurality of the first analytical data computed continuously, wherein

when there is the variation among the plurality of the first analytical data computed continuously, the variation determination portion makes the fast Fourier transformation computation portion sequentially output the plurality of the first analytical data to the revolution computing portion, and

when there is no variation among the plurality of the first analytical data computed continuously, the variation determination portion makes the fast Fourier transformation computation portion compute second analytical data under a second data length which is longer than the first data length, and output the second analytical data to the revolution computing portion, and

the revolution computing portion computes the number of revolutions of the object based on one of the plurality of first analytical data, and the second analytical data.

2. A revolution indicator according to claim 1, wherein the first analytical data is spectrum data, and wherein the variation of the first analytical data determined by the variation determination portion is the variation of frequency showing a maximum value of the spectrum data.

3. A revolution indicator according to claim 1, wherein the first analytical data is fast-Fourier-transformed with a lower number of sampling points than that of the second analytical data which is computed in the same frequency range.

4. A revolution indicator according to claim 2, wherein the first analytical data is fast-Fourier-transformed with a lower number of sampling points than that of the second analytical data which is computed in the same frequency range.

5. A revolution indicator according to claim 1, wherein the first analytical data is computed so that the data detected under the second data length is computed by the zero-suppress processing which leaves only a specific range of the data, making the others zero in order to perform the fast Fourier transform.

6. A revolution indicator according to claim 2, wherein the first analytical data is computed so that the data detected under the second data length is computed by the zero-suppress processing which leaves only a specific range of the data, making the others zero in order to perform the fast Fourier transform.

7. A non-transitory computer readable medium containing instructions stored therein for causing a computer processor to perform the following steps, including:

a detecting step, executed on a computer, to detect data related to a physical phenomenon resulting from the revolving movement of a measuring object;

a fast Fourier transformation computing step, executed on the computer, in which the detected data in the detecting step is fast-Fourier-transformed under a first data length and first analytical data is computed and output; and

a revolution computing step, executed on the computer, to compute a number of the revolutions of the measuring object, wherein

the program for revolution indicator includes the following steps;

a step to make the fast Fourier transformation computing step compute a plurality of the first analytical data continuously under the first data length based on the data successively detected in the detecting step, and to execute a variation determination step to determine whether there is a variation or not among the plurality of the continuously computed first analytical data, and

when there is a variation among the plurality of the first analytical data continuously computed, the variation determination step makes the fast Fourier transformation computing step sequentially output the plurality of the first analytical data computed under the first data length to the revolution computing step, and

when there is no variation in the first analytical data computed continuously, the variation determination step makes the fast Fourier transformation computing step compute second analytical data under a second data length which is longer than the first data length and output the second analytical data to the revolution computing step, and

the revolution computing step computes the number of revolutions of the object based on one of the plurality of first analytical data, and the second analytical data.

8. A non-transitory computer-readable medium containing instructions stored therein for causing a computer processor to perform the steps comprising:

detecting data related to a physical phenomenon resulting from the revolving movement of an object;

performing a fast Fourier transform (FFT) of the detected data related to the detected physical phenomenon under a first data length;

computing a plurality of first analytical data based upon the FFT data;

determining whether there is variation among the plurality of first analytical data;

outputting the plurality of first analytical data when it is determined that there is the variation among the plurality of first analytical data;

computing a second analytical data under a second data length which is longer than the first data length, when there is no variation among the plurality of first analytical data and outputting the second analytical data; and

computing a number of revolutions of the object based on one of the plurality of first analytical data and the second analytical data.