JPH11271021A - Waveform analyzer and displacement measuring apparatus using the analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a displacement measuring apparatus which is low-cost, whose setting operation is easy and which is handled simply and to realize a waveform analyzer which can be used for the displacement measuring apparatus by a method wherein an inclination corresponding to every small region of an input signal is found by using an inclination detector and inclinations obtained in neighboring regions are integrated by a totalization computing unit. SOLUTION: A displacement measuring apparatus is constituted of a waveform analyzer 11-4, of a microphone 11-1 which is connected to it and of a monitor 11-5 as an output means. The microphone 11-1 senses a reflected sound, as an analog signal, which is generated when a sound existing in the natural word is reflected by an object. The analog signal as an electric signal is converted into a digital signal by an A/D converter so as to be sent to the waveform analyzer 11-4. In the waveform analyzer 11-4, the signal from the microphone 11-1 is processed by an inclination detector 11-2, an inclination corresponding to every small region of an input signal is found, and results which are obtained in neighboring regions with reference to inclinations in respective points are sent to a totalization computing unit 11-3. Processed results which are integrated by the totalization computing unit 11-3 are sent to the monitor 11-5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveform analyzer which can determine a waveform of target information from an input signal mixed with a target information waveform. The present invention relates to a displacement measuring device that can detect the position of an object or the displacement of some signal from an input waveform irrespective of whether it is periodic or excessive by using the above.

[0002]

2. Description of the Related Art A conventional waveform analyzer performs a waveform analysis using a convolution operation using a sine wave or the like as a multiplication coefficient as shown in FIGS. Was getting. FIG. 12A shows a case where a normal sine wave is used as a multiplication coefficient. Since the sine wave itself is used as the multiplication coefficient, the obtained result has a good resolution in the frequency domain. FIG.
(B) is a case where a sine wave multiplied by a window function (for example, a function whose center value is 1 and its peripheral value is 0 and monotonically decreases toward the periphery) is used as a multiplication coefficient. The resolution in the frequency domain is poor because it is not a wave, but the resolution in the time domain is good because the length of the multiplication coefficient is short.

[0003] What can be said in common to the waveform analyzers of FIGS. 12 (a) and 12 (b) is that it is difficult to simplify the calculation because the multiplication coefficient is constituted by a curve that is difficult to approximate by a straight line. There is a point that it is difficult to simplify the circuit configuration especially when hardware is used. Further, in order to detect a bias of the waveform as shown in FIG. 13, that is, a signal in which the peak position of the waveform is shifted to the left or right, a sine wave having a different frequency from a low frequency to a high frequency is used as a multiplication coefficient and a plurality of Since the convolution operation must be performed and the plurality of obtained results must be integrated while paying attention to the phase, the calculation becomes complicated, and it is also difficult to implement hardware.

On the other hand, a typical example of a measuring device for obtaining the displacement of an object is a laser measuring device as shown in FIG. The laser measuring device has a light emitting section 98-
1, a laser light receiving section 98-2, an analyzer 98-3, and an output device 98-4. With laser measuring instruments,
First, a laser beam is emitted from the light emitting unit 98-1 toward an object whose displacement is to be measured. The laser light reflected from an appropriate portion of the object is obtained as a signal including information on the object by the light receiving unit 98-2. The signal obtained by the light receiving section 98-2 is sent to the analyzer 98-3. The analyzer 98-3 performs a predetermined process on the transmitted signal to obtain a temporal displacement of a portion of the target object where the laser light is reflected. Analysis device 98-
3 sends the obtained result to the output device 98-4. The output device 98-4 displays the temporal displacement of the object, for example, as shown in FIG.

[0005] The processing performed by the analyzer 98-3 depends on the principle of measurement employed by the laser measuring instrument. For example, it is also possible to measure the time until the laser light is reflected and received, that is, the time required for the laser light to reciprocate to the object, and convert the measured time to the displacement of the object. Alternatively, the displacement can be converted into the displacement of the target object using interference generated between the laser light emitted from the light emitter and the laser light received after reflection. In general, laser measuring instruments have the advantage of being able to perform accurate measurements, but the equipment itself is expensive and requires complex alignment during actual measurement.
There is a problem that care must be taken in handling. From the above-mentioned problems, it can be understood that the laser measuring device is not suitable for use in a case where a large number of measuring devices are permanently installed in a structure outdoors or the like. In the example described above, it cannot be said that the technique of waveform analysis is effectively used. For example, in the method using interference, waveform analysis is used in the sense that the obtained interference waveform is analyzed. However, the laser light emitting device and the light receiving device can be replaced with other inexpensive and easy-to-use devices. It is not used in a positive sense that makes it possible.

[0006]

Accordingly, the present invention is suitable for, for example, a case where a large number of measuring instruments are permanently installed outdoors for measuring the waveform of vibration generated on a bridge, a road or the like outdoors. It is an object of the present invention to realize a displacement measuring instrument for displacement that is inexpensive, easy to set, and easy to handle, and to realize a waveform analyzer that can be used as the measuring instrument for displacement.

[0007]

The technical solution taken by the present invention is a waveform analyzer for obtaining a waveform of target information from an input signal mixed with a target information waveform. The waveform analyzer may include a slope detector that calculates a slope corresponding to each small area of the input signal, and a total calculator that integrates the slope obtained in a neighboring area with respect to the slope at each point. A waveform analyzer characterized by comprising a means for performing a convolution operation using a multiplication coefficient that is not centrally symmetric. A waveform analyzer characterized in that a curve changing from one end to the other end performs a convolution operation using a multiplication coefficient in which at least the sign of the slope is constant, wherein the slope detector has one end and the other end. A waveform analyzer characterized by performing a convolution operation using a multiplication coefficient which is connected to the end by a straight line and is not centrally symmetric, wherein the length of the multiplication coefficient used in the inclination detector is equal to the length of the input signal. What is claimed is: 1. A waveform analyzer characterized in that the wavelength is not more than 1/4 of the wavelength determined from the highest frequency component, and the summation calculator that integrates the slopes has a lower frequency component than the lowest frequency component of the input signal. Waveform analyzer characterized by having a function of a low-pass filter that allows the signal to pass through, wherein the aggregation calculator that integrates the slopes can extract a value with a high frequency of appearance. Waveform analyzer
The slope detector is a waveform analyzer characterized by comprising a delay element and a difference circuit, characterized in that the delay element of the slope detector, a sampling circuit and a hold circuit are connected in series. The difference circuit of the tilt detector is a waveform analyzer characterized in that it is an operational amplifier, and the aggregation calculator is characterized by connecting an operational amplifier and a capacitor in parallel A sensor that detects vibration, a waveform analyzer that can determine a waveform of target information from input signals obtained by the sensor, and an output signal from the waveform analyzer. A displacement measuring instrument comprising an output device, wherein a waveform analyzer used for the displacement measuring instrument is any one of the waveform analyzers described above. Wherein the sensor for detecting the vibration is a displacement measuring device, which is a microphone for detecting vibration of air, that is, sound, and the sensor for detecting the vibration is a sensor that is in close contact with an object of displacement measurement. There is provided a displacement measuring device.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a waveform analyzer having a signal processing function according to an embodiment of the present invention and a displacement measuring device using the waveform analyzer will be described with reference to the drawings. FIG. 1 shows a first example of a displacement measuring device including a waveform analyzer.
It is a lineblock diagram of an embodiment. As shown in FIG. 1, the displacement measuring device is a microphone 11-1 which is an input device, a waveform analyzer 1
1-4, and a monitor 11-5 as an output means. Further, the waveform analyzer 11-4 includes a tilt detector 11-2,
It is composed of an aggregation calculator 11-3.

The waveform analyzer 11-4 comprises a microphone 11-
1, and the signal detected by the microphone 11-1 is sent to the waveform analyzer 11-4. The waveform analyzer 11-4 is connected to the monitor 11-5, and the processing result of the waveform analyzer 11-4 is displayed on the monitor 11-5. In the waveform analyzer 11-4, the signal from the microphone 11-1 is processed by the tilt detector 11-2, and the result is sent to the totalizing calculator 11-3.
Also, the processing result of the tallying calculator 11-3 is sent to the monitor 11-5. Note that the microphone 11-1 includes a portion that senses sound as an analog signal, and an A / D converter that converts the analog signal into a digital signal. The monitor 11-5 is provided with a D / A converter so that digital input is possible. Therefore, in the first embodiment, the waveform analyzer 11-4 performs all the processes of the waveform analysis on digital signals.

FIG. 2 is a diagram showing a flow of data in displacement measurement. First, a sound 12-1 shown in FIG. 3 or a sound 12-3 shown in FIG.
Is issued. The sound 12-1 or the sound 12-3 is reflected by the object as shown in FIG.
-4 and arrives at the microphone 11-1. The microphone 11-1 converts the sound 12-2 or the sound 12-4 into an analog electric signal, and sends it as a digital signal to the waveform analyzer 11-4 through a built-in A / D converter. In the measurement of FIG. 2, a sound source existing in the natural world is diverted. However, a sound source such as a synthesizer that generates a pure sound may be actively prepared and used. A buzzer or the like that generates a sound to be held may be used. Further, a device such as a white noise generator that generates a broadband sound may be used. When a sound source is actively prepared, the sound source may be fixed to a displaceable portion of the object.

FIG. 3 is a diagram showing a state in which the sound 12-1 which is a pure sound changes to the sound 12-2 when the object is displaced. When the object is displaced, the frequency of the sound 12-2 which is the reflection sound of the sound 12-1 changes according to the speed of the displacement of the object. For example, when the displacement of the object changes according to a curve as shown in FIG. 3, the displacement speed represented by the slope at each point of the curve gradually increases, and after the point at which the displacement reaches a maximum, gradually increases. It will decrease. At this time, the frequency of the sound 12-2 gradually increases in the same manner as the speed of displacement of the object, and gradually decreases after a point at which the frequency reaches a maximum. This phenomenon in which the frequency changes according to the displacement speed of the object is a general phenomenon called the Doppler effect in the field of physics.

A wide-band sound including a high-frequency sound and a low-frequency sound can be decomposed into waveforms of respective frequency bands as shown by a sound 12-3 in FIG. With respect to the waveform in each frequency band, the frequency changes in accordance with the displacement speed of the object with the same effect as that described with reference to FIG. The sound 12-4, which is a reflection of the sound 12-3, is obtained by synthesizing a waveform for each frequency band that has undergone the above-described frequency change. In the following description of the waveform analyzer 11-4, the sound 12-1 and the reflected sound 12-2 are mainly described for simplicity, but the sound 12-1 is a basic effect.
-3 and the sound 12-4. However, in the case of the waveform analyzer 11-4 to be described later, since the phenomenon over a wide band can be detected, the use of the sound 12-3 which is a sound of a wide band can perform a measurement more resistant to noise.

The inclination detector 11-2 included in the waveform analyzer 11-4 is a convolution calculator using the multiplication coefficient shown in FIG. FIG. 5 shows typical multiplication coefficients that can be used for inclination detection. Each of the multiplication coefficients shown in FIGS. 5A, 5B, and 5C has the same performance as the basic function of detecting the inclination. The difference is the effect on the DC component of the sound 12-2 or 12-4 which is the input waveform. For example, when inclination detection is performed by a convolution operation using the multiplication coefficient a, the sound 12-
Since the DC component included in the sound 2 or the sound 12-4 becomes zero, the DC component generated in the subsequent processing can be the DC component when the object is displaced. When the multiplication coefficient b is used, the DC component included in the sound 12-2 or the sound 12-4 is stored. Using the multiplication coefficient c, sound 1
The DC component included in 2-2 or sound 12-4 is multiplied by a gain. As described above, these multiplication coefficients can be properly used depending on the necessity of the DC component of the input waveform.

The multiplication coefficient length CL of the multiplication coefficient needs to be set as shown in FIGS. As shown in FIG. 5, when the multiplication coefficient length CL is the tone 12-1 which is a pure tone,
Assuming that the wavelength is WL, it is necessary that (WL / 4)> CL Equation (1). In the case of the sound 12-3 which is a wideband sound, the wavelength of the sound having the highest frequency in the sound 12-3 can be set as WL in a range satisfying the expression (1). In the present embodiment, the waveform analysis is performed by digital processing. In this case, as shown in FIG. 5, the multiplication coefficient length CL is obtained by setting the sampling cycle determined by the A / D converter built in the microphone 11-1 to SL. , CL> = SL can be set within a range that satisfies Expression (2).

When the waveform analysis is performed by analog processing, equation (1) must be observed in the same manner as in digital processing, but equation (2) is not applied because the concept of sampling itself disappears. . Instead, it is limited by the frequency characteristics of the circuit element that actually performs the tilt detection. Here, a specific example of the waveform analyzer having the signal processing function of the present invention will be described. This waveform analyzer is constituted by a combination of basic circuit elements.

FIG. 7 shows a configuration of a waveform analyzer 21-9 of the present embodiment corresponding to the above-described waveform analyzer 11-4. The waveform analyzer 21-9 according to the present embodiment includes a microphone 21-1 as input means and a monitor 2 as output means.
1-10. The microphone 21-1 is a device that detects sound and outputs it as an analog electric signal. The monitor 21-10 is a device that receives an analog signal and displays a shape as a waveform. Waveform analyzer 21-
Reference numeral 9 denotes a tilt detector 21-5 and a counting calculator 21-8. The tilt detector 21-5 receives an input waveform from the microphone 21-1 and outputs an output from the tilt detector 21-5. The data is input to the tallying calculator 21-8, and finally, the tallying calculator 21-8.
-8 is connected so that the output of -8 can be output to the monitor 21-10.

The inclination detector 21-5 includes sampling-and-hold circuits 21-2 and 21-3, and an operational amplifier 21-.
4. The sampling and holding circuit is a circuit that samples the value of an input signal when a clock signal is detected as shown in FIG. 9 and holds the value until the next clock signal is detected. As shown in FIG.
When the hold circuits are connected in series, the value held by the sampling & hold circuit 21-2 is a value obtained by the sampling immediately before the value held by the sampling & hold circuit 21-3. The sampling and hold circuits 21-2 and 21- obtained in this manner.
If one of the values held by 3 is input to the positive polarity of the operational amplifier 21-4 and the other is input to the negative polarity, the tilt detector 21-5 as a whole can perform difference calculation, that is, tilt detection.

The totalizing calculator 21-8 includes a capacitor 21
-6 and the operational amplifier 21-7 are connected in parallel, and the output of the tilt detector 21-5 is input to the negative polarity of the operational amplifier 21-7. With such a connection, the aggregation calculator 21
At -8 as a whole, the effect of a low-pass filter will occur. The gain k of the operational amplifier serves as a parameter in determining the frequency characteristics of the low-pass filter. In the embodiments described above, the waveform analyzer configured using the basic circuit elements has been described.
It goes without saying that other differently configured waveform analyzers capable of producing a similar effect with a simple combination of these basic circuit elements can be employed.

FIG. 8 shows a variation of the tilt detector 21-5 shown in FIG. 7 as a tilt detector 22-8. The tilt detector 22-8 is an example of obtaining a tilt from values of three adjacent sampling points. First, the sampling and holding circuits 22-1, 22-2 and 22-3 are connected in series in order to obtain values of three adjacent sampling points. By connecting these three sampling and holding circuits in series, values of three adjacent sampling points can be obtained. Next, 3
The values of two sampling points adjacent to the value of one sampling point are input to a circuit group including an operational amplifier 22-4, an operational amplifier 22-5, and an operational amplifier 22-6 in consideration of the polarity. By inputting as shown in FIG. 8, the above two values can be added. If the gain k of each of the operational amplifier 22-4 and the operational amplifier 22-5 is adjusted, the above-described addition can be made a weighted addition.

The added value of the two adjacent sampling points obtained in this way and the value of the remaining one sampling point are converted into an operational amplifier 22- which operates similarly to the operational amplifier 21-4 shown in FIG. 7, the difference calculation, that is, the inclination detection can be performed. Thus, FIG.
The tilt detector 22-8 shown in (1) performs tilt detection from the values of three adjacent sampling points. Note that tilt detector 2
2-8 can detect a tilt having more complicated characteristics as compared with the tilt detector 21-5 shown in FIG. This difference is due to the difference in the number of input points.

The operation and effect of the entire waveform analyzer 11-4 will be described with reference to FIG. FIG. 10A shows a waveform of the sound 12-2 similar to FIG. 3 for explanation. When such a waveform is subjected to inclination detection by a convolution operation using the multiplication coefficient a shown in FIG. 5A, the following result is obtained. FIG. 10C shows a waveform extracted from a region having a frequency similar to that of the sound 12-1. When the slope obtained at each point is plotted, a relatively high-frequency waveform equivalent to the frequency of the sound 12-1 is obtained. FIG. 10B shows a waveform extracted from a region where the frequency increases according to the speed of the target object. If the slope obtained at each point is plotted as it is, a waveform near the frequency of the sound 12-1 appears as in FIG. 10C. Cancel the waveform near the frequency of -1. That is, the absolute value of the slope obtained at each point is compared with a suitable small area in the vicinity, and the largest one is extracted. The largest gradients among the appropriate small areas obtained in this way are shown as, for example, gradients GL and GR in FIG.

Since the waveform shown in FIG. 10B is a waveform in a region where the frequency increases in accordance with the speed of the object, the gradient GL obtained at the left point indicating temporally and the gradient GL are obtained. Comparing the gradient GR obtained at the right point showing the following, | GL | <| GR | Equation (3), which indicates that there is a relatively long-period fluctuation. When the same processing as that performed in FIG. 10B is performed on the waveform illustrated in FIG. 10A, for example, | Gl | <| Gm | <| Gh | , The gradient Gm, the gradient Gh, etc.
Again, it can be seen that a long-period fluctuation occurs. Since the change in the inclination corresponds to the change in the frequency of the sound 12-2, it can be seen that the change in the inclination is also associated with the displacement of the object, which was the original cause.

From the above results, when the inclination detector 11-2 acts on the sound 12-2, a relatively short-period fluctuation around the frequency of the sound 12-1 and a comparison corresponding to the displacement of the object are obtained. It can be seen that the waveform has a mixture of the fluctuation of the long period and the long period. Therefore, if the summing operation unit 11-3 acts as a low-pass filter on the result of the inclination detector 11-2, it is possible to easily remove a relatively short-period fluctuation around the frequency of the sound 12-1. As a result, a relatively long-period fluctuation corresponding to the displacement of the object as shown in FIG. 10D can be obtained. Further, if the processing described in FIG. 10B is performed by the tally calculator 11-3, a relatively long-period fluctuation corresponding to the displacement of the object as shown in FIG. 10E can be obtained.

The displacement of the object obtained in this manner can be detected regardless of the performance limitation such as the lower limit frequency of the microphone 11-2 used, which can be detected. As the multiplication coefficients used in the inclination detector 11-2, those shown in FIG. 11 can be used. These multiplication coefficients can be used because the output of the same tendency as the multiplication coefficient of FIG. 5 is output although the performance of the slope detection is lower than that of the multiplication coefficient shown in FIG. Note that FIG.
The multiplication coefficient shown in FIG. 11A has a waveform whose peak position is shifted left and right and is not symmetrical. The multiplication coefficient shown in FIG. 11B is a curve in which a line connecting one end to the other end has at least a constant sign of the slope. In some cases, the multiplication coefficient shown in FIG. 11C is obtained by subjecting the multiplication coefficient shown in FIG. 6 to band limitation such that a part of the band is removed in the frequency domain.

In the above description, the microphone has been described as the input means. However, a vibration sensor for detecting vibration can be used as the input means. In this case, for example, if the lower limit frequency fL that can be detected is determined as the performance of the vibration sensor itself, and the wavelength of fL is set to WL, the length of the multiplication coefficient used in the tilt detector 11-2 is determined. Is set to WL / 4 or less, and the characteristics of the low-pass filter executed by the summing operation unit 11-3 are set so that only frequencies f satisfying f <fL are passed and other frequencies f are not passed. As a result, the waveform analyzer 11-
As a whole effect, it is possible to detect a signal waveform in a lower frequency region than the lower limit frequency fL that can be detected by the vibration sensor. In the above description, an example is described in which a signal waveform whose domain is time is detected, but equivalent waveform analysis can be performed even for a signal waveform whose domain is space. . The signal whose definition area is a space is an image or the like, and typical input means for outputting such a signal waveform include a CCD line sensor and a CCD area sensor. Moreover, the present invention may be embodied in various other ways without departing from its spirit and essential characteristics.

[0026]

As described in detail above, according to the present invention, a displacement measuring instrument which can be manufactured at low cost, does not require complicated alignment, and is easy to handle. A waveform analyzer that can be used for measurement exceeding the performance (lower detectable frequency) of a microphone or a vibration sensor can be obtained. Further, according to the present invention (inclination of inclination to small area + totaling), signals which are spread over a wide band and mixed can be handled collectively by the same procedure.
Therefore, the detected mixed signal becomes relatively large compared to the noise, and a waveform analyzer that can perform a measurement that is strong against the noise as a whole can be obtained. Also, in the present invention, excellent effects such as that noise that causes adverse effects in the conventional method can be effectively used as sound emitted from a sound source in the natural world can be achieved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment relating to a displacement measuring device including a waveform analyzer.

FIG. 2 is a diagram showing a data flow in displacement measurement.

FIG. 3 shows a sound 12- being a pure sound when an object is displaced.
FIG. 3 is a diagram showing a state in which 1 changes to a sound 12-2.

FIG. 4 is a diagram in which a wideband sound including a high-frequency sound to a low-frequency sound is made into a waveform in each frequency band.

FIG. 5 is a diagram of a typical multiplication coefficient that can be used for tilt detection.

FIG. 6 is an explanatory diagram of a multiplication coefficient length CL of a multiplication coefficient.

FIG. 7 is a configuration diagram illustrating an example of a waveform analyzer according to the present embodiment.

FIG. 8 is a diagram showing another embodiment of the tilt detector shown in FIG. 7;

FIG. 9 is a diagram showing a relationship among an input signal, a clock signal, and an output signal in a tilt detector.

FIG. 10 is a diagram illustrating the operation of the waveform analyzer according to the embodiment.

FIG. 11 is another example of a multiplication coefficient used in the tilt detector according to the embodiment.

FIG. 12 is an explanatory diagram of performing a waveform analysis by using a convolution operation with a sine wave or the like performed by a conventional waveform analyzer as a multiplication coefficient.

FIG. 13 is a diagram of a signal in which the waveform is biased, that is, the peak position of the waveform is shifted left and right.

FIG. 14 is a configuration diagram of a laser measuring device for obtaining a displacement of an object.

FIG. 15 is an output waveform obtained by the measuring device shown in FIG.

[Explanation of symbols]

11-1, 21-1 Microphones 11-2, 21-5, 22-8 Tilt detectors 11-3, 21-8 Total calculators 11-4, 21-9 Waveform analyzers 11-5, 21-10 Monitors 21-2, 21-3, 22-1 to 3 Sampling & Hold Circuit 21-4, 21-7 Operational Amplifier 21-6, Capacitors 22-1, 22-2, 22-3 Sampling & Hold Circuit 22-4, 5 , 6, 7 operational amplifier

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Toshimitsu Musha 2-13-17 Minami Tsukushino, Machida, Tokyo

Claims (15)

[Claims] 1. A waveform analyzer for obtaining a waveform of target information from an input signal mixed with a target information waveform, said waveform analyzer corresponding to each small region of the input signal. A waveform analyzer, comprising: a tilt detector for obtaining a tilt; and a totalizing calculator for integrating a tilt obtained in a neighboring area with respect to the tilt at each point. 2. The waveform analyzer according to claim 1, wherein said inclination detector comprises means for performing a convolution operation using a multiplication coefficient which is not centrally symmetric. 3. The slope detector according to claim 1, wherein a curve changing from one end to the other end performs a convolution operation using a multiplication coefficient having at least a constant sign of the slope. The waveform analyzer according to claim 2. 4. The tilt detector according to claim 1, wherein one end and the other end are connected by a straight line and the convolution operation is performed using a multiplication coefficient which is not centrally symmetric. 2. The waveform analyzer according to 1. 5. The apparatus according to claim 2, wherein a length of a multiplication coefficient used in said tilt detector is equal to or less than ４ of a wavelength obtained from a highest frequency component of the input signal. The waveform analyzer according to any one of the preceding claims. 6. The summation arithmetic unit for integrating the slope has a function of a low-pass filter that passes a frequency component lower than the lowest frequency component of the input signal. The waveform analyzer according to any one of claims 1 to 5. 7. The waveform analyzer according to claim 1, wherein the totaling calculator that integrates the slopes can extract a value having a high frequency of appearance. 8. The waveform analyzer according to claim 4, wherein said inclination detector comprises a delay element and a difference circuit. 9. The waveform analyzer according to claim 8, wherein the delay element of the tilt detector is configured by connecting a sampling circuit and a hold circuit in series. 10. The waveform analyzer according to claim 8, wherein the difference circuit of the tilt detector is an operational amplifier. 11. The waveform analyzer according to claim 6, wherein said totaling arithmetic unit comprises an operational amplifier and a capacitor connected in parallel. 12. A sensor for detecting vibration, a waveform analyzer for obtaining a waveform of target information from an input signal obtained by the sensor, and an output device for displaying an output signal from the waveform analyzer. Displacement measuring device characterized by becoming. 13. A displacement measuring instrument according to claim 1, wherein said waveform analyzer is one of the waveform analyzers according to claim 1. 14. A displacement measuring instrument according to claim 12, wherein said sensor for detecting said vibration is a microphone for detecting air vibration, that is, sound. 15. The displacement measuring device according to claim 12, wherein the sensor for detecting vibration is a sensor that is brought into close contact with an object to be measured for displacement.