JPH0526722A - Method and device for diagnosing contribution of sound source or vibration source - Google Patents

Abstract

PURPOSE:To obtain a method and a device for diagnosing contribution which enable analysis of the degree of the contribution of a sound source or a vibration source to a sound or vibration at an evaluation point, in a state of actual operation and on a real time basis. CONSTITUTION:A method for diagnosing the contribution of a sound source or a vibration source diagnoses the degree of the contribution of one or a plurality of sound sources or vibration sources to a sound or vibration at an evaluation point. Each detection signal of the sound or the vibration detected in the vicinity of each sound source or vibration source is inputted to adapted filters 41, 42, 43 and 44 and the sum of the respective output signals Ea, Eb, Ec and Ed of the adapted filters 41, 42, 43 and 44 is determined. The coefficient of each of the adapted filters 41, 42, 43 and 44 is updated automatically so that a difference between an aimed signal of the sound or the vibration detected at the evaluation point and the sum of the output signals be the minimum, and the degree of the contribution of each sound source or vibration source is diagnosed on the basis of the output signal of each of the adapted filters 41, 42, 43 and 44 at the time point when the difference converges to some definite value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for diagnosing contribution of a sound source or a vibration source, and has one or a plurality of sound sources or vibration sources, which cause the sound and vibration at the evaluation point. In such transmission systems as general mechanical equipment, automobiles, building structures, office automation equipment, railways, etc., it is necessary to identify the parts or transmission paths that have a large contribution in terms of sound and vibration, and to improve efficiently. It can be used to do things.

[0002]

2. Description of the Related Art In acoustic / vibration systems, a method called masking is generally used to know the degree of influence of a sound source or a vibration source. In this method, the influence of a certain sound source or vibration source is shielded by a lead plate or sound insulating material, or eliminated by a damping material, and the degree of each influence is judged by comparison with the normal state. In addition to this, the true transfer function is obtained by removing the correlation component from the transfer function between each sound source or vibration source and the evaluation point, and thereby the degree of influence of each sound source or vibration source on the evaluation point,
That is, a contribution analysis method in the frequency domain has been devised that determines the degree of contribution.

[0003]

[Problems to be Solved] However, in the above-mentioned masking method, in a system in which sound and vibration influence each other like a general mechanical device, the effect on other parts is eliminated and the sound or vibration of a certain part is eliminated. Since it is impossible to completely block it, it is not possible to completely know the effect of only that part. That is, there is a problem that it is impossible to grasp the contribution in the actual operating state.

The contribution analysis method in the frequency domain includes
Only amplitude information is used and phase information is not considered,
Analysis becomes difficult if there is a strong correlation between the inputs. Furthermore, there is a problem that analysis takes time and results cannot be obtained immediately, and long-term steady data is required.

The present invention has been made in view of the above points,
The purpose of this is to enable analysis in actual operating conditions,
The point is to provide a highly practical contribution diagnosis method of a sound source / vibration source and its apparatus.

[0006]

In order to achieve the above object, the present invention provides a method for diagnosing the degree of contribution of one or more sound sources or vibration sources to sound or vibration at an evaluation point. , The target of the sound or vibration detected at the evaluation point by inputting each detection signal of the sound or vibration detected in the vicinity of each of the sound sources or vibration sources to the adaptive filter and obtaining the sum of the output signals of the respective adaptive filters The sound source or vibration is automatically updated by the output signal of each adaptive filter at the time when the coefficient of each adaptive filter is automatically updated so that the difference between the signal and the sum of the output signal is minimized. The method for diagnosing the contribution of sound sources and vibration sources was used to diagnose the degree of contribution of the source.

The effect of a certain sound source or vibration source is not removed, and the degree of contribution can be diagnosed in an actual operating state. Phase information can be taken into consideration, and even if there is a correlation between input signals, analysis is possible, and transient phenomenon analysis and real-time contribution analysis can also be performed.

Further, in a device for diagnosing the degree of contribution of one or a plurality of sound sources or vibration sources to the sound or vibration at the evaluation point, the sound or vibration arranged near each of the sound sources or vibration sources. Detecting means for detecting, an adaptive filter for inputting the detection signals of the respective detecting means, an adding means for inputting all output signals of the respective adaptive filters to obtain a sum of the output signals, and a sound or vibration at the evaluation point. Detecting means for detecting, and means for automatically updating the coefficient of the adaptive filter so that the difference between the target signal detected by the detecting means and the sum of the output signals of the adaptive filters by the adding means is minimized, The difference between the sum of the output signals and the target signal converges to a certain value, and the output signal of each adaptive filter determines the sound source or the sound source for the sound or vibration at the evaluation point. It can be a device having the by the contribution diagnostic device of sound sources and vibration sources and display means for displaying the degree of contribution of the vibration source, the practicality excellent can achieve the function and effect.

[0009]

EXAMPLES An example of the present invention shown in FIGS. 1 to 4 will be described below. FIG. 1 is an application example of contribution analysis of mechanical noise. The general machine 1 often emits noise due to vibrations of the motor 2, which is a power source, the power transmission system 3 such as gears and belts, and the bearing system 4. Therefore, the vibration sensor 5a is installed in the four parts A, B, C, D of the machine 1.
, 5b, 5c, 5d are arranged, and the microphone 6 is installed at an evaluation point X 1.2 m above the ground, which is a fixed distance from the general machine 1.

The detection signals from the vibration sensors 5a, 5b, 5c and 5d and the target signal from the microphone 6 are input to the contribution analyzer 10. The contribution analysis device 10 is provided with a result display section 11 corresponding to each part A, B, C, D of the general machine 1.

A block diagram of the contribution analysis of the contribution analysis apparatus 10 is shown in FIG. Signals from the vibration sensors 5a, 5b, 5c, 5d and the microphone 6 are low-pass filters LPF21, 22, which are anti-aliasing filters, respectively.
Input to 23, 24, 25, and the output signals are A / D
The signals are input to the converters 31, 32, 33, 34, 35 and output as digital signals.

The output digital signals from the A / D converters 31, 32, 33, 34 based on the respective vibration sensors 5a, 5b, 5c, 5d are input to the adaptive digital filters ADF41, 42, 43, 44, and are filtered. After the product-sum calculation with the coefficient, the output signals Ea, Eb, Ec, Ed are input to the arithmetic circuit 50, respectively. The target signal from the A / D converter 35 based on the microphone 5 is also input to the arithmetic circuit 50.

In the arithmetic circuit 50, the output signals Ea and Eb are
, Ec, Ed, the sum is obtained, the residual signal K which is the difference from the target signal from the A / D converter 35 is calculated, and the residual signal K is calculated by the adaptive digital filters ADF41, 42, 43, 44
Send to. Each adaptive digital filter ADF41, 42, 43, 44
Can be schematically represented by a block as shown in FIG. 3, and each of the adaptive digital filters ADF41, 42, 43, 44 updates the filter coefficient so as to minimize the residual of the residual signal K.

In this way, each adaptive digital filter ADF41, at the time when the residual of the residual signal K converges to a constant value,
From the output signals Ea, Eb, Ec, Ed of 42, 43, 44, the degree of contribution of vibration of each part A, B, C, D of the general machine 1 is judged. Output signals Ea, Eb, Ec, Ed at the time of adaptation
Is shown in FIG. The result is displayed on the result display unit 11.

In the case of the present example, as is apparent from FIG. 4, the output signal Ec has a remarkably large amplitude as compared with the others.
From this, it is understood that the vibration of the portion C of the motor of the general machine 1 greatly contributes to the noise at the evaluation point X. It can be seen that the next contribution is the portion D of the motor bearing of the general machine 1.

As described above, each part A, B, of the general machine 1
The degree of contribution to the sound at the evaluation points X of C and D can be easily determined.

Adaptive digital filters ADF41, 42, 43,
The 44 is also suitable for including phase information, and can easily handle short-term data and perform real-time contribution analysis, which makes it extremely practical. That is, measurement and measures can be performed continuously,
It is possible to efficiently extract effective countermeasure parts, and it has considerable advantages over conventional masking methods and frequency domain contribution analysis methods.

If it is desired to analyze the band of interest of the input signal, the object can be achieved by placing a band pass filter or a high pass / low pass filter immediately before each adaptive filter shown in FIG. In addition to the above-described embodiment, the present invention can be applied to various fields such as sound and vibration problems of cars, sound source identification of railway noise, noise problems of office automation equipment, and vibration problems of building structures.

[0019]

By using the contribution diagnosis method and apparatus according to the present invention, the degree of contribution to the evaluation point of the sound source or the vibration source can be discriminated in real time and in real time in a complicated acoustic / vibration system. Therefore, it is possible to efficiently and accurately take soundproof and antivibration measures. It can also be applied to the selection of a sound source or vibration source with high causality during active control of sound or vibration.

[Brief description of drawings]

FIG. 1 is a diagram showing a contribution analysis system for a general machine according to an embodiment of the present invention.

FIG. 2 is a block diagram of a contribution analysis apparatus of the same embodiment.

FIG. 3 is a schematic block diagram of an adaptive digital filter ADF.

FIG. 4 is a diagram showing a result of contribution analysis.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... General machine, 2 ... Motor, 3 ... Power transmission system, 4 ... Bearing system, 5a, 5b, 5c, 5d ... Vibration sensor, 6 ... Microphone, 10 ... Contribution analysis device, 11 ... Result display part, 21, 2
2, 23, 24, 25 ... Low-pass filter LPF, 31, 32, 3
3, 34, 35 ... A / D converter, 41, 42, 43, 44 ... Adaptive digital filter ADF, 50 ... Operation circuit.

Claims (2)

[Claims] 1. A method for diagnosing the degree of contribution of one or a plurality of sound sources or vibration sources to sound or vibration at an evaluation point, wherein each of the sounds or vibrations detected in the vicinity of the respective sound source or vibration source. The detection signals are respectively input to the adaptive filters, the sum of the output signals of the respective adaptive filters is obtained, and the difference between the target signal of the sound or vibration detected at the evaluation point and the sum of the output signals is minimized. A sound source / vibration source characterized by automatically updating the coefficient of each adaptive filter and diagnosing the degree of contribution of each sound source or vibration source by the output signal of each adaptive filter at the time of convergence to a certain constant value. Contribution diagnosis method. 2. A device for diagnosing the degree of contribution of one or a plurality of sound sources or vibration sources to sound or vibration at an evaluation point, wherein the sound or vibration is arranged near each of the sound sources or vibration sources. Detecting means for detecting
An adaptive filter that inputs the detection signals of the respective detection means, an addition means that inputs all output signals of the respective adaptive filters and obtains the sum of the output signals, a detection means that detects sound or vibration at the evaluation point, Means for automatically updating the coefficient of the adaptive filter so that the difference between the target signal detected by the detecting means and the sum of the output signals of the adaptive filter by the adding means is minimized; Display means for displaying the degree of contribution of each sound source or vibration source to the sound or vibration at the evaluation point by the output signal of each adaptive filter when the difference from the target signal converges to a certain value Contribution diagnostic device for sound source and vibration source.