Method and apparatus for adjusting vibration frequency of vibrating object
First Claim
1. A method for conducting stepwise adjustment of the vibration frequency of a vibrating object by operating a vibration frequency varying means connected to said vibrating object to make said vibration frequency of said vibrating object substantially equal to a reference frequency, comprising the steps of:
- a. measuring the vibration frequency of said vibrating object;
b. operating said vibrating frequency varying means by an increment to cause the vibrating frequency to change and measuring the resulting vibration frequency of the vibrating object;
c. stopping the operating step whenever the difference between said resulting vibration frequency measured in a preceding step of operating and the reference frequency is smaller than a certain predetermined permissible frequency error;
d. continuing to operate, whenever said difference is not smaller than said certain permissible frequency error, said vibration frequency varying means to cause the vibrating frequency to successively change by a present increment determined by;
the past increment in the immediately prior step of operating, the frequency representing the difference between the vibration frequencies of the vibrating object before and after said immediately prior step of operating said vibration frequency varying means, and the frequency deviation representing that frequency difference relative to the reference frequency still remaining after the immediately prior step of operating; and
e. repeating steps (c) through (d) until the vibration frequency of the vibrating object becomes substantially equal to the frequency.
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Abstract
A method and an apparatus for adjusting the vibration frequency of vibrating objects such as piano strings, by stepwise adjustment of the vibration frequency of a vibrating object. The amount of the required adjusting operation in each of the adjustment steps is calculated by the equation:
Δθ.sub.i = K.sub.i (f.sub.s - f.sub.pi-1)
wherein:
i represents an integer such as 1, 2, 3, ...;
Δθi represents the amount of adjustment in the i-th adjusting step;
fpi -1 represents the vibration frequency after the (i-1)th adjusting step;
Ki represents the constant employed in the calculation of the i-th adjusting step;
The constant (K1) for the initial (i=1) adjusting step is predetermined; and
The constant Ki (i=2, 3, ...) for the second and subsequent adjusting steps is calculated by the equation: ##EQU1## WHEREIN: ΔθI-1 REPRESENTS THE AMOUNT OF ADJUSTMENT IN THE (I-1)TH ADJUSTING STEP;
fpi-2 represents the vibration frequency after the (i-2)th adjusting step.
The vibration body needs to be kept vibrating only for the period of time required for the measurement of the vibration frequency in each adjusting step. This method and the apparatus is applicable to vibrating objects such as the strings of piano whose vibration amplitude undergoes rapid attenuation.
48 Citations
8 Claims
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1. A method for conducting stepwise adjustment of the vibration frequency of a vibrating object by operating a vibration frequency varying means connected to said vibrating object to make said vibration frequency of said vibrating object substantially equal to a reference frequency, comprising the steps of:
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a. measuring the vibration frequency of said vibrating object; b. operating said vibrating frequency varying means by an increment to cause the vibrating frequency to change and measuring the resulting vibration frequency of the vibrating object; c. stopping the operating step whenever the difference between said resulting vibration frequency measured in a preceding step of operating and the reference frequency is smaller than a certain predetermined permissible frequency error; d. continuing to operate, whenever said difference is not smaller than said certain permissible frequency error, said vibration frequency varying means to cause the vibrating frequency to successively change by a present increment determined by;
the past increment in the immediately prior step of operating, the frequency representing the difference between the vibration frequencies of the vibrating object before and after said immediately prior step of operating said vibration frequency varying means, and the frequency deviation representing that frequency difference relative to the reference frequency still remaining after the immediately prior step of operating; ande. repeating steps (c) through (d) until the vibration frequency of the vibrating object becomes substantially equal to the frequency. - View Dependent Claims (2, 3)
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4. An apparatus for conducting stepwise adjustment of the vibration frequency fp of a vibrating object to make said vibration frequency fp substantially equal to a reference frequency fs through an adjusting process consisting of a number i of steps of operating a vibration frequency varying means through the increments Δ
- θ
1 which are calculated in accordance with the equation;
space="preserve" listing-type="equation">Δ
θ
.sub.i = K.sub.i (f.sub.s - f.sub.pi-1) . . . (1)wherein; i represents an integer indicating the number of a given operating step; Δ
θ
i represents the increment to be carried out by said vibration frequency varying means in the i-th operating step;fpi-1 represents the resulting vibration frequency in the (i-1)th operating step; Ki represents the constant employed in the calculation of the i-th operating step; the constant K1 for the first (i=1) adjusting step being predetermined; the constant K.sub. i (i=2, 3, . . .) for the second and subsequent adjusting steps being calculated in accordance with the equation;
##EQU8## wherein;
Δ
θ
i-1 represents the increment to be carried out by said vibration frequency varying means in the (i-1)th operating step;fpi-1 represents the resulting vibration frequency in the (i-1)th operating step; fpi-2 represents the resulting vibration frequency in the (1-2)th operating step; said apparatus comprising; means for causing vibration of said vibrating object; means for detecting said vibration of said vibrating object; control means for, upon receipt of the output of said detecting means measuring the vibration frequency of the vibrating object, generating a signal corresponding toa the measured vibration frequency, upon receipt of an external start signal prior to conducting said first (i=1) adjusting step, actuating said vibration-causing means to cause vibration of said vibrating object and, thereafter, detecting the end of each operation to actuate said vibration-causing means; a calculating unit including means for setting said reference vibration frequency f.sub. s and said first constant K1, Ki calculating means for, upon receipt of the aforesaid signal generated from said control means and corresponding to said measured vibration frequency, calculating the constant Ki (i=2, 3, . . .) for the second (i=2) and subsequent (i=3, 4, . . .) operating steps in accordance with equation (2), and Δ
θ
i calculating means for calculating in accordance with equation (1) that increment for the respective operating steps (i=1, 2, 3, . . .); andoperating means which, upon receipt of the output of the Δ
θ
i calculating means of said calculating unit, operates the vibration frequency varying means through an amount Δ
θ
i calculated by said Δ
θ
i calculating means,said operating process being stopped whenever the difference between the resulting vibration frequency in the nearest prior operating step and said referency frequency is smaller than a predetermined permissible frequency error set error. - View Dependent Claims (5, 6, 7, 8)
- θ
Specification