JP2001033477A - Dynamic quantity sensor and displacement measuring apparatus using this dynamic quantity sensor, displacement measuring method, apparatus and method for vibration control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To directly detect the time differentiation of acceleration, i.e., jerk. SOLUTION: If an acceleration (a) acts on a base portion 3, a cantilever body 4 is curved, and an angular velocity Ω is generated at its tip part. The angular velocity Ω is detected by a vibrating gyro 5. If the acceleration (a) is constant, the cantilever body 4 becomes at a standstill at a certain quantity of deflection. Since any angular velocity Ω is not generated at the tip part of the cantilever body 4, on this occasion, the output of the vibrating gyro 5 becomes zero. Until the acceleration (a) changes in point of time, the cantilever body 4 does not curve, and any angular velocity Ω is not generated at the tip part, and the vibrating gyro 5 does not generate an output. Namely, the vibrating gyro 5 outputs a signal according to the time differentiation of the acceleration (a), i.e., jerk.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical quantity sensor for detecting a mechanical quantity generated in a mechanical structure such as a building or a bridge when vibration is applied to the mechanical structure, and an application technique thereof. A physical quantity sensor suitable for monitoring the deterioration and damage of the mechanical structure itself by detecting the occurrence and propagation of cracks (cracks) in the mechanical structure (this technology is also called health monitoring). Related to its applied technology.

[0002]

2. Description of the Related Art As a technique for inspecting the occurrence and progress of cracks in the above-mentioned mechanical structure, a method using, for example, an acceleration sensor is conventionally known. This focuses on the fact that mechanical structures such as buildings and bridges vibrate in a natural environment due to various factors (for example, the movement of humans and vehicles and the influence of wind). Thus, the occurrence and progress of the cracks and the like are detected.

That is, an acceleration sensor is attached to a mechanical structure such as a building or a bridge, and the vibration state of the mechanical structure is monitored from the output of the acceleration sensor. Here, it is assumed that the above-described crack does not occur or propagate in the mechanical structure, and the so-called mechanical structure is in a static state. In this case, the output of the acceleration sensor changes continuously according to the vibration of the mechanical structure. However, it is known that when a crack occurs or a crack develops in a mechanical structure, the output of the acceleration sensor becomes temporally discontinuous (in other words, a high-frequency component is generated) at that time. . This discontinuity corresponds to the time derivative of acceleration, so-called jerk, and is generally a jerk (Jerk:
The unit is called [m / sec ² / sec] or [ft / sec ² / sec].

Therefore, the jerk can be obtained by differentiating the output of the acceleration sensor, and the occurrence of cracks or the like in the mechanical structure or the progress thereof can be detected. In order to obtain this differential value, a generally known analog type differential circuit may be used, or CP
It can also be obtained by digital processing using a U (central processing unit), a DSP (digital processing unit), or the like. When the deterioration or damage of the mechanical structure due to the cracks or the like progresses, the frequency and amplitude of occurrence of the discontinuous portion increase, so that the progress of deterioration and damage of the mechanical structure can be grasped from these changes.

[0005] Apart from the method using the acceleration sensor,
Conventionally, a method using a strain gauge is also known. this is,
By attaching a strain gauge to the surface of the machine structure to be monitored, the bending generated in the machine structure due to the crack or the like is directly measured.

[0006]

However, according to the method using an acceleration sensor among the above-mentioned prior arts, differentiating means for differentiating the output of the acceleration sensor must be provided in order to obtain the jerk. Therefore, there is a problem that the configuration becomes complicated and the cost increases. In addition, since the noise component included in the output of the acceleration sensor is emphasized by providing the differentiating means, in order to reduce the noise component, a filter such as a low-pass filter is actually provided on the input side of the differentiating means. Means need to be provided. Therefore, by providing this filter means and the differentiating means,
There is also a problem that the response as a sensor is reduced. Further, when a CPU or DSP is used as the differentiating means, for example, the processing by the CPU or DSP takes a certain amount of time, so that there is a problem that real-time (real-time) performance is lacking.

Further, in the method using the strain gauge, only the deflection of the portion to which the strain gauge is attached can be detected.
Therefore, if the entire machine structure is to be detected, an enormous number of strain gauges are required, and there is a problem that it is often impossible to realize.

Accordingly, an object of the present invention is to provide a dynamic quantity sensor that functions as a so-called jerk sensor that can directly detect the jerk value without using the differentiating circuit and the like. It is another object of the present invention to provide a technique capable of detecting the bending of a mechanical structure in a wider range than the method using the strain gauge.

[0009]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a base mounted on a surface of a mechanical structure to be measured, and a base mounted on the base. A deformed portion having a bent portion that is fixed and that bends in a direction along the vibration direction with the portion fixed to the base portion as a base point when the mechanical structure vibrates in a predetermined direction; Angular velocity detecting means provided at a predetermined distance from a portion of the portion fixed to the base portion via the bending portion, and detecting an angular velocity at the position.

According to the first aspect of the present invention, when the mechanical structure vibrates in the predetermined direction, the deformed portion fixed to the mechanical structure via the base portion moves in the vibration direction. Vibrates while bending in the direction along. And
In response to the vibration, an angular velocity is generated at a position of the deformed portion where the angular velocity detecting means is provided, and the angular velocity is detected by the angular velocity detecting means.

Here, for example, it is assumed that a constant acceleration acts on the base portion in one direction along the predetermined direction due to the vibration of the mechanical structure. In this case, the deformed portion (strictly, a bent portion of the deformed portion) bends by a fixed amount in accordance with the acceleration, and stands still in a state of being bent by the fixed amount. Therefore, no angular velocity is generated at the position of the deformed portion where the angular velocity detecting means is provided, and the output of the angular velocity detecting means becomes zero (0).

On the other hand, when the acceleration changes with time,
In accordance with this change in acceleration, the amount of deflection of the deformed portion also changes over time. As a result, an angular velocity according to the temporal change of the acceleration is generated at the position of the deformed portion where the angular velocity detecting means is provided. Therefore, the angular velocity detecting means generates an output corresponding to the angular velocity, that is, an output corresponding to a temporal change of the acceleration.

As described above, when the acceleration acting on the base portion changes over time due to the vibration of the mechanical structure, the angular velocity detecting means outputs the change over time, that is, the output corresponding to the jerk value. Generate. That is, claim 1 of the present invention
The physical quantity sensor according to the invention described in (1) functions as a so-called jerk sensor that directly detects (measures) a jerk value acting on the base portion due to vibration of the mechanical structure.

Therefore, unlike the prior art in which jerk is obtained by differentiating the output of the acceleration sensor, it is not necessary to provide a differentiating means such as a differentiating circuit. Therefore, the configuration of the entire sensor can be simplified and the cost can be reduced accordingly. Further, according to the above prior art, as described above, a filter means such as a low-pass filter must be provided on the input side of the differentiating means, so that the responsiveness is reduced. According to this, since the jerk value can be directly detected, the responsiveness is higher than that described above, and S
Jerk detection (measurement) with a high / N ratio can be realized.

According to a second aspect of the present invention, in the physical quantity sensor according to the first aspect of the present invention, the deformable portion is a cantilever extending along a direction intersecting the vibration direction. One end of the cantilever is fixed to the base, and the other end of the cantilever is provided with the angular velocity detecting means.

That is, the amount of bending (bending) of the cantilever with respect to the bending moment is generally known as Bernoulli
Based on Euler's law. Therefore, if the deformed portion is constituted by such a cantilever, a deformed body that bends in a desired manner with respect to the vibration characteristics (for example, frequency and amplitude) of the mechanical structure can be relatively easily designed, Consequently, a jerk sensor suitable for a mechanical structure can be designed.

According to a third aspect of the present invention, in the physical quantity sensor according to the second aspect of the present invention, the so-called resonance frequency at which the cantilever resonates with the vibration is set to the actual frequency of the mechanical structure. It is set higher than the vibration frequency.

When the deformable body is formed of a cantilever as described above, the cantilever resonates with vibration of a specific frequency. In the frequency range lower than the resonance frequency, the ratio of the output of the angular velocity detecting means to the jerk value (ie, the value obtained by dividing the output of the angular velocity detecting means by the jerk value), that is, the jerk sensitivity of the dynamic quantity sensor is , And becomes substantially constant. This is clear from the calculation formula based on Bernoulli-Euler's law, and can be proved from actual experimental results.

Therefore, according to the third aspect of the present invention, the resonance frequency is set higher than the actual vibration frequency of the mechanical structure. In this way, jerk measurement can be realized with a constant sensitivity to jerk regardless of the frequency of the vibration. Note that the actual vibration frequency of the mechanical structure may be measured in advance.

According to a fourth aspect of the present invention, in the physical quantity sensor according to the second aspect of the present invention, the so-called resonance frequency at which the cantilever resonates with the vibration is determined by the actual frequency of the mechanical structure. This is set near the vibration frequency.

As described above, the cantilever resonates with vibration of a certain specific frequency. At this resonance frequency, the sensitivity to jerk is maximized. This means
It is clear from the above formula based on Bernoulli-Euler's law, and can also be proved from actual experimental results.

Therefore, according to the present invention, the resonance frequency is set near the actual vibration frequency of the mechanical structure. In this way, jerk measurement can be realized with maximum anti-jerk sensitivity.

According to a fifth aspect of the present invention, in the physical quantity sensor according to the first aspect of the present invention, the angular velocity detecting means is constituted by a gyroscope means.

That is, the fifth aspect of the present invention embodies the angular velocity detecting means. The above-mentioned gyroscope means can be constituted by various types of gyroscopes such as generally known vibrating gyroscopes, optical fiber gyroscopes, and coma gyroscopes.

According to a sixth aspect of the present invention, there is provided a dynamic quantity sensor according to the first aspect of the present invention, and displacement deriving means for deriving a displacement of the mechanical structure itself due to the vibration based on an output of the dynamic quantity sensor. And

That is, by detecting the jerk value with the physical quantity sensor according to the first aspect of the present invention, it is possible to recognize, for example, the occurrence of a crack in the mechanical structure and the progress of the crack. This is because the generation and progress of the crack is accompanied by the generation of a discontinuous high-frequency component. Therefore, in the invention according to claim 6, the state displacement of the mechanical structure itself, for example, the progress of deterioration or damage, etc., is grasped from the output of the physical quantity sensor.

According to a seventh aspect of the present invention, there is provided a mechanical quantity sensor for detecting a mechanical quantity generated in a mechanical structure to be measured when the mechanical structure vibrates along a predetermined direction. 2. The displacement measuring method according to claim 1, further comprising an attaching process and a displacement deriving process of deriving a displacement of the mechanical structure itself based on an output of the mechanical sensor. This uses a physical quantity sensor.

That is, the present invention according to claim 7 relates to a displacement measuring method which has the same function and effect as the displacement measuring device according to claim 6.

According to an eighth aspect of the present invention, there is provided a physical quantity sensor according to the first aspect of the present invention, and a vibration applying means for intentionally applying a vibration along the predetermined direction to the mechanical structure according to a vibration control signal; Vibration control means for generating the vibration control signal in a state where the vibration of the mechanical structure itself is suppressed based on the output of the physical quantity sensor and supplying the vibration control signal to the vibration applying means.

That is, according to the present invention, when the mechanical structure vibrates, the vibration is suppressed by intentionally applying another vibration to the mechanical structure from the outside, for example. This is an invention relating to a so-called active type vibration damping device. For example, it is now assumed that the mechanical structure vibrates in a direction along the predetermined direction. This vibration is detected by the physical quantity sensor according to the first aspect of the present invention.
Then, based on the output of the physical quantity sensor, the vibration control means controls the vibration applying means to intentionally apply vibration to the mechanical structure so as to suppress the vibration of the mechanical structure itself (details will be described in detail below). Generates the vibration control signal for realizing this control).

It is to be noted that such an anti-vibration device can also be realized by using, for example, an acceleration sensor instead of the above-mentioned physical quantity sensor. However, the above-mentioned physical quantity sensor has a time change of acceleration,
That is, since the differential value is directly detected, it is possible to realize an anti-vibration device with much higher responsiveness than when an acceleration sensor is used.

According to a ninth aspect of the present invention, when a mechanical structure to be measured vibrates along a predetermined direction, a mechanical quantity sensor for detecting a mechanical quantity generated in the mechanical structure is provided on the mechanical structure. A condition for deriving a vibration condition necessary for suppressing the vibration of the mechanical structure itself by applying a vibration along the predetermined direction to the mechanical structure based on the mounting process and the output of the mechanical quantity sensor. Derivation process,
A vibration applying step of applying vibration to the mechanical structure in accordance with the vibration condition derived and derived in the condition deriving step, wherein the physical quantity sensor according to claim 1 is used as the physical quantity sensor. Things.

That is, the ninth aspect of the present invention relates to an anti-vibration method which has the same function and effect as the anti-vibration apparatus of the eighth aspect of the present invention.

According to a tenth aspect of the present invention, when a mechanical structure to be measured vibrates and the mechanical structure bends, a plurality of points on a surface along a predetermined surface of the mechanical structure are generated. An angle detecting means for detecting a change in a bending angle with respect to the predetermined surface at a plurality of locations spaced apart from each other by a predetermined distance in a direction along the predetermined surface; and A relative difference between the changes in the deflection angles at any two points among the changes in the deflection angles at each point is determined, and the change in the amount of deflection of the mechanical structure between the arbitrary two points, for example, the curvature is calculated from the relative difference. Or, a deflection amount deriving unit for deriving a change in a radius of curvature or the like.

For example, it is now assumed that the mechanical structure vibrates and the surface is curved so as to be concave or convex, for example. Then, the angle detecting means detects a change in the bending angle with respect to the predetermined surface at a plurality of locations on the surface.
Then, the bending amount deriving means obtains a relative difference in a change in the bending angle with respect to the predetermined surface at any two places, and, based on the relative difference, a change in the bending amount of the mechanical structure between the two places, ie, a one-dimensional change. Derive a change in the amount of deflection. Therefore, if the change in the amount of deflection between the other two locations is derived,
A change in the bending of the mechanical structure can be detected, for example, two-dimensionally.

Thus, according to the physical quantity sensor of the tenth aspect of the present invention, it is possible to detect (measure) a change in the amount of deflection of the mechanical structure due to vibration over a wide range. Therefore, the bending of the entire mechanical structure can be detected with a smaller number of sensors than in the conventional technique of detecting the bending of the mechanical structure using the above-described strain gauge. In the method using the strain gauge, the mechanical structure itself is affected by the (parallel) expansion and contraction change without bending. However, according to the invention of claim 10, only the bending of the mechanical structure is performed. The change in deflection due to the vibration can be detected (identified).

According to an eleventh aspect of the present invention, in the physical quantity sensor according to the tenth aspect of the present invention, each of the portions is three
As described above, they are positioned substantially linearly.

That is, according to the eleventh aspect of the present invention, three or more locations for detecting the deflection angle on the surface of the mechanical structure are provided substantially in a straight line. Therefore,
If the deflection amount deriving means derives a plurality of changes in the deflection amount between any two locations by different combinations of the locations, the change in the one-dimensional deflection amount in the direction in which the locations are arranged is partially corrected. In detail.

According to a twelfth aspect of the present invention, in the physical quantity sensor according to the tenth aspect of the present invention, the angle detecting means is a plurality of angular velocity detecting means arranged at the respective locations.

The twelfth aspect of the present invention embodies the angle detecting means. That is, each of the angular velocity detecting means constituting the angle detecting means detects an angular velocity generated in a portion where the mechanical structure is bent due to bending of the mechanical structure, and detects the predetermined angular position of the portion where the mechanical structure is disposed. Of the deflection angle with respect to the surface is determined.

According to a thirteenth aspect, in the physical quantity sensor according to the twelfth aspect, the angular velocity detecting means is constituted by a gyroscope means.

According to a fourteenth aspect of the present invention, the output of the physical quantity sensor according to the tenth aspect of the present invention and the output of the physical quantity sensor for the vibration when the mechanical structure is normal are stored in advance. Means, a displacement deriving means for comparing the stored content stored in the storage means with the output of the physical quantity sensor and for deriving a displacement of the mechanical structure itself due to the vibration from, for example, a difference or a ratio thereof, It is provided with.

The term "when the mechanical structure is normal" means, for example, when the mechanical structure has no damage such as a crack.

According to the fourteenth aspect of the present invention, when the mechanical structure is normal, the output of the physical quantity sensor according to the tenth aspect of the present invention and the stored contents stored in the storage means in advance And the difference between them becomes substantially zero (when the ratio is obtained, it becomes 1). On the other hand, for example, when a crack is generated in the mechanical structure and is located between the above-mentioned arbitrary two places, the bending between these arbitrary two places becomes large. Therefore, a difference is generated between the output of the physical quantity sensor and the storage content of the storage means, and the size of the crack can be grasped from the difference or the ratio, and thus the progress of deterioration or damage of the mechanical structure. State displacement can be grasped.

According to a fifteenth aspect of the present invention, there is provided a dynamic quantity sensor according to the eleventh aspect, wherein each of the flexures between two or more of the outputs of the physical quantity sensor is different from each other in two or more combinations of the locations. Displacement deriving means for comparing the change in the amount and deriving the displacement of the mechanical structure itself due to the vibration from the difference or ratio thereof.

According to the fifteenth aspect of the present invention, when the mechanical structure is normal, the change in the amount of bending of the mechanical structure is substantially constant between any two locations. on the other hand,
It is assumed that a crack has occurred between certain two locations. Then, the change in the amount of bending between the two locations is greater than the change in the amount of deflection between the other two locations where cracks do not occur. Therefore, the size of the crack can be grasped from the difference or the ratio of the change in the amount of bending between each of the two points without providing the storage means as in the invention of the fourteenth aspect. Further, the position where the crack occurs can be specified depending on which of the two portions has a large change in the amount of bending.

According to a sixteenth aspect of the present invention, there is provided an attaching step of attaching a mechanical quantity sensor for detecting a mechanical quantity generated in a mechanical structure to be measured to the mechanical structure when the mechanical structure vibrates; A storage process for pre-storing the output of the physical quantity sensor with respect to the vibration when the mechanical structure is normal, and comparing the contents stored in this storage process with the output of the physical quantity sensor, and comparing the difference or ratio, etc. A displacement deriving step of deriving a displacement of the mechanical structure itself due to the vibration, wherein the physical quantity sensor of the invention according to claim 10 is used as the physical quantity sensor.

That is, the invention according to claim 16 is an invention relating to a displacement measuring method which has the same operation and effect as the displacement measuring device according to claim 14 of the present invention.

According to a seventeenth aspect of the present invention, when a mechanical structure to be measured vibrates, a mechanical quantity sensor for detecting a mechanical quantity generated in each of a plurality of different portions on the mechanical structure is provided. A displacement that derives a displacement of the mechanical structure itself due to the vibration from a difference, a ratio, or the like, by comparing an output process of the mechanical quantity sensor relating to the respective portions on the mechanical structure with an attaching process of attaching the mechanical structure to the object. And a deriving step, wherein the physical quantity sensor according to the invention is used as the physical quantity sensor.

That is, the invention of claim 17 is an invention relating to a displacement measuring method having the same operation and effect as the displacement measuring device of the invention of claim 15.

According to an eighteenth aspect of the present invention, there is provided a dynamic quantity sensor according to the tenth aspect, vibration applying means for applying vibration to the mechanical structure according to a vibration control signal, and an output of the physical quantity sensor. Vibration control means for generating the vibration control signal in a state in which the bending of the mechanical structure itself is suppressed and supplying the vibration control signal to the vibration applying means.

That is, an eighteenth aspect of the present invention is an invention for realizing the above-mentioned active type vibration damping device using the physical quantity sensor according to the tenth aspect of the present invention. For example, it is now assumed that the mechanical structure vibrates and the vibration causes the mechanical structure itself to bend. This deflection is detected by the physical quantity sensor according to the tenth aspect of the present invention. Then, based on the output of the physical quantity sensor, the vibration control means controls the vibration applying means so as to intentionally apply vibration to the mechanical structure so as to suppress the bending of the mechanical structure itself (details). Generates the vibration control signal for realizing this control).

According to a nineteenth aspect of the present invention, there is provided a method for mounting a mechanical quantity sensor for detecting a mechanical quantity generated in a mechanical structure when the mechanical structure to be measured vibrates, to the mechanical structure, A condition deriving process for deriving a vibration condition necessary to suppress the deflection of the mechanical structure itself by giving vibration to the mechanical structure based on the output of the mechanical quantity sensor, and a condition deriving process in the condition deriving process. A vibration applying step of applying vibration to the mechanical structure in accordance with the obtained vibration conditions, wherein the mechanical quantity sensor according to claim 10 is used as the physical quantity sensor.

That is, the nineteenth aspect of the present invention relates to an anti-vibration method having the same operation and effect as the anti-vibration device of the eighteenth aspect.

[0055]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. Note that the first
The embodiment is based on the premise that a so-called jerk sensor for directly detecting the jerk described above is realized and this sensor is applied, that is, the invention of claims 1 to 9 of the present invention. Is a concrete example of

FIG. 1 shows a schematic configuration of a sensor 1 according to the first embodiment. As shown in FIG.
Is a substantially rectangular parallelepiped base 3 mounted on the mechanical structure 2 to be measured, and a substantially flat cantilever 4 having one end fixed on the base 3 and the other end free.
And a vibrating gyroscope 5 fixed to the upper surface of the other end of the cantilever 4. The mechanical structure 2 is
It mainly vibrates in the direction indicated by arrow 2a in FIG. And
The base 3 and the cantilever 4 are made of metal such as aluminum. Further, the cantilever body 4 is provided in such a state that its deflected plane is oriented substantially perpendicular to the vibration direction 2a of the mechanical structure 2 and extends along a direction intersecting the vibration direction 2a. The vibrating gyroscope 5 detects an angular velocity in a direction indicated by an arrow 5a in FIG. 2, and has a configuration as shown in FIG. 2, for example.

That is, the vibrating gyroscope 5 has a base portion 51 having a predetermined shape (in the figure, a flat plate shape), and a corner whose one end is fixed to one surface of the base portion 51 and extends in a vertical direction from the one surface. And a columnar vibrating portion 52. Further, the vibrating section 52 has a substantially square cross section across the length direction thereof, and electrodes 53 to 56 each having a long piezoelectric structure are adhered to each side surface. Here, for convenience of explanation, as shown in the figure, the x-axis (the axis along the direction in which the electrodes 53 and 55 face each other), the y-axis (the axis along the length direction of the vibrator 52), and the z-axis (the electrode (Coordinates along the direction in which 54 and 56 are opposed to each other).

Of the electrodes 53 to 56, a pair of electrodes facing each other, for example, the electrodes 54 and 56 facing each other along the z-axis are driving electrodes, and when an AC driving voltage is applied to them, Along the direction along the z-axis,
(Free end) vibrates. Here, for example, when the angular velocity Ω acts on the vibrating body 52 in the direction of rotation about the longitudinal direction as shown by an arrow 5a in the same figure, the other end of the vibrating body 52 is generally known. Due to the applied Coriolis force, it is bent in one direction along the x-axis direction perpendicular to the z-axis direction. Therefore, the angular velocity Ω can be detected by detecting the voltage generated between the electrodes 53 and 55 facing each other along the x-axis. The size of the vibrating gyroscope 5 is, for example, such that the length of the vibrating body 52 is about 5 m.
m, which is extremely small.

Now, in the configuration shown in FIG.
It is assumed that a constant acceleration a acts on the base 3 in one direction (upward or downward) along the direction indicated by the arrow 2a in FIG. In this case, the cantilever 4 is bent by an angle θ corresponding to the magnitude of the acceleration a, and the bending angle θ
Stand still with. This relationship is expressed by the following equation 1 based on Bernoulli-Euler's law described above.

[0060]

(Equation 1)

In the equation 1, K is a constant constant with respect to the frequency f of the vibration (in other words, each frequency ω in the portion where the vibration gyro 5 is provided).

Accordingly, in the state where θ in the above equation 1 does not change, the angular velocity Ω does not occur in the portion where the vibrating gyroscope 5 is provided, and the output of the vibrating gyroscope 5 becomes substantially zero.

On the other hand, when the acceleration a changes with time, the cantilever 4
Also changes with time. As a result, an angular velocity Ω corresponding to the temporal change of the acceleration “a” is generated also in the portion where the vibration gyro 5 is provided. This relationship is obtained by time-differentiating both sides of Equation 1 and is expressed by the following Equation 2.

[0064]

(Equation 2)

In Equation 2, the time derivative of the deflection angle θ on the left side corresponds to the angular velocity Ω in the portion where the vibrating gyroscope 5 is provided. On the other hand, the time derivative of the acceleration a on the right side corresponds to the jerk J. When this relationship is arranged, the following equation 3 is obtained.

[0066]

(Equation 3)

That is, according to Equation 3, the vibration gyro 5
By detecting the angular velocity Ω at the other end of the cantilever body 4, the jerk J acting on the base portion 3 can be detected.

Next, the results of an actual trial production of the sensor 1 and experiments on the prototype will be described.

First, the characteristics of the single sensor 1 were measured by the configuration shown in FIG. That is, the sensor 1 is attached to the vibrator 6 and the sensor 1 at each vibration frequency f is set.
To analyze the output V _j in the FFT analyzer 7. Exciter 6
The vibration frequency f, amplitude, etc. are controlled by the signal generator 8. In this experiment, a cantilever 4 having a vibration frequency f that resonates at about f = about 90 Hz was used.

[0070] Figure 4, the ratio of the output V _j of the vibrating gyroscope 5 for acceleration a acting on the sensor 1 (that is, the value obtained by dividing the output V _j of the vibration gyro acceleration a), shows a so-called pair acceleration sensitivity. In the figure, the horizontal axis indicates the vibration frequency f, and the vertical axis indicates the sensitivity to acceleration. Also, in the figure, (b) is an enlarged view of the low frequency region in (a). According to FIG. 4 (especially according to FIG. 4B), it can be seen that in a frequency range lower than the resonance frequency (f ≒ 90 Hz), the higher the frequency f, the higher the sensitivity to acceleration. On the other hand, although not shown, it is known that the sensitivity to acceleration of a general acceleration sensor is constant with respect to the frequency f. Therefore, according to the sensor 1 according to the present embodiment, detecting the jerk value J having a higher frequency than the normal vibration frequency f of the mechanical structure 1 is more advantageous than the acceleration sensor.

[0071] Figure 5, the ratio of the output V _j of the vibrating gyroscope 5 for jerk J acting on the sensor 1 (that is, the value obtained by dividing the output V _j of the vibrating gyroscope at the jerk value J), shows a so-called pair jerk sensitivity characteristics. In the figure, the horizontal axis indicates the vibration frequency f, and the vertical axis indicates the jerk sensitivity.
Also, in the figure, (b) is an enlarged view of the low frequency region in (a). According to FIG. 5 (particularly according to FIG. 5B), the resonance frequency (f ≒ 90H)
z) In the lower frequency range, the jerk sensitivity is constant regardless of the frequency f. Therefore, if the resonance frequency is set higher than the normal vibration frequency f of the mechanical structure 1, stable jerk J detection can always be realized.

FIG. 6 shows data obtained by inputting a jerk J having a constant frequency f to the sensor 1 and measuring the output V of the vibrating gyroscope 5 while changing the jerk value J. In addition,
In the figure, the horizontal axis shows the jerk value J, indicates the output V _j of the vibratory gyroscope 5 the vertical axis. The frequency f at this time is f = 50 Hz. According to FIG. 6, if the frequency f is constant, the output of the vibration gyro 5, that is, the output of the sensor 1 is proportional to the jerk value J. That is, it is understood that the jerk value J can be directly detected by the sensor 1. Note that this relationship corresponds to the frequency f
Is the same when f is other than f = 50 Hz.

Next, an experiment was conducted on the impulse response of the sensor 1 with the configuration shown in FIG. That is, as shown in the figure, the sensor 1 is fixed on a damper 9 made of hard rubber. Then, the approximate center of the base portion 3 is beaten by the impulse hammer 10 (via the cantilever 4) to apply an impulse acceleration. V _j of the sensor 1 at this time is represented by F
The analysis is performed by the FT analyzer 7. Incidentally, for comparison reference, on the base part 3 of the sensor 1 (via a cantilever body 4) the acceleration sensor 11 is provided, analyzed by FFT analyzer 7 is also the output V _g of the acceleration sensor 11. Also in this experiment, a cantilever 4 having a vibration frequency f that resonates at about f = about 90 Hz was used.

[0074] in FIG. 8 (a), shows the response of the output V _g of the acceleration sensor 11. Then, in FIG. (B), shows the response of the output V _j of the sensor 1 according to the first embodiment. In the figure, the horizontal axis indicates time t, and the vertical axis indicates each output _Vg or _Vj . As is clear from the comparison, the S / N ratio in the impulse response (portion indicated by an arrow in each graph) is higher in the sensor 1 according to the first embodiment than in the acceleration sensor 11. It is much better (parts indicated by arrows in each graph).

The characteristics shown in FIG. 8A and FIG. 8B expressed by the frequency f characteristic (spectrum) are as follows.
9 (a) and 9 (b) respectively. In each of the figures, the dotted lines in the graph show the respective outputs V _g and V _j when there is no impulse input. According to FIG. 9A, since other noise components are largely present at frequencies lower than the frequency of the impulse (the portion indicated by the arrow in the graph) obtained by the acceleration sensor 11, these impulse It is difficult to distinguish noise from noise, that is, the S / N ratio is extremely low. On the other hand, as shown in FIG.
The frequency component of the impulse (the part indicated by the arrow in the graph) obtained by detection by the sensor 1 is (self)
Due to the differential effect, it becomes very large, and conversely, the low frequency noise component becomes minimal. Therefore, the acceleration sensor 1
An impulse response with a higher S / N ratio can be obtained as compared with 1.

Further, in the configuration of FIG. 3, a random vibration having a frequency f = 0 to 50 Hz is generated by the signal generator 8 in order to simulate low frequency noise vibration. At the same time, in order to simulate the occurrence or propagation of cracks, a discontinuous vibration having a center frequency around frequency f = 60 Hz (hereinafter, this vibration is referred to as crack vibration) is generated. The output V _{j of the} sensor 1 is measured. The sensor 1 is used for comparison.
On the base unit 3 (via a cantilever body 4) is provided an acceleration sensor 11, it is also analyzed by FFT analyzer 7 for the output V _g of the acceleration sensor 11.

[0077] in FIG. 10 (a), shows the response of the output V _g of the acceleration sensor 11. FIG. 2B shows the response of the output _Vj of the sensor 1. In each figure, the horizontal axis indicates time t, and the vertical axis indicates each output _Vg or _Vj .
Then, the crack vibration is applied at the time indicated by the arrow in each figure. As is clear from the comparison, the crack vibration, that is, the jerk J, which can hardly be detected by the acceleration sensor 11, is reliably detected by the sensor 1 according to the first embodiment. it can. This is because the crack vibration has a high frequency component.

FIG. 10 (a) and FIG. 10 (b)
The measurement results of
11 (a) and 11 (b) respectively. According to FIG. 11A, the jerk J obtained by the detection by the acceleration sensor 11 (the portion indicated by the arrow in the graph)
It can be seen that crack vibration cannot be detected as shown in FIG. On the other hand, as shown in FIG. 11B, according to the sensor 1 according to the first embodiment, the crack vibration (portion indicated by an arrow in the graph) is distinguished from the low-frequency noise component. Can be detected. Note that, in FIG.
The nearby peak is the resonance frequency (phenomenon) of the cantilever 4 constituting the jerk sensor 1.

According to the jerk sensitivity characteristic shown in FIG. 5, when the vibration frequency f is located at the resonance frequency of the cantilever 4, the jerk sensitivity becomes maximum. Therefore, the output _Vj of the sensor 1 when the jerk J near the resonance frequency is input to the sensor 1 is measured.

That is, in the configuration of FIG.
A vibration frequency f that resonates around f = about 160 Hz is used. The output V of the sensor 1 when the signal generator 8 generates random vibration distributed at a frequency f = 0 to 120 Hz and also generates a discontinuous crack vibration having a center frequency near the frequency f = 160 Hz. Measure _j . At the same time, for comparison reference, also analyzed by FFT analyzer 7 for the output V _g of the acceleration sensor 11.

[0081] in FIG. 12 (a), shows the response of the output V _g of the acceleration sensor 11. FIG. 2B shows the response of the output _Vj of the sensor 1. At the time indicated by the arrow in each figure, crack vibration is applied. As is clear from the comparison, the crack vibration that can be detected only delicately by the acceleration sensor 11 can be reliably detected by the sensor 1 according to the first embodiment. Part indicated by an arrow). Also, comparing FIG. 12 (b) with FIG. 10 (b), it can be seen that it is more advantageous to use the sensor 1 near the resonance frequency.

FIG. 12 (a) and FIG. 12 (b)
The measurement results of
13 (a) and 13 (b) respectively. As is apparent from this spectrum analysis, the sensor 1 by the use in the vicinity of the resonance frequency, it is possible to take out large output V _j of the sensor 1. Conversely, low frequency noise can be suppressed.

As described above, according to the sensor 1 of the first embodiment, the occurrence and propagation of cracks in the mechanical structure 2 can be directly measured. Therefore, using the sensor 1, an experiment for actually monitoring the occurrence and progress of cracks in the mechanical structure 2 was performed. FIG. 14 shows the schematic diagram of the experimental apparatus.

As shown in the figure, this experimental apparatus has a base 12 and four columns 1 in a state facing the base 12.
And a ceiling portion 14 supported by 3, 13,..., And between the ceiling portion 14 and the base portion 12, the elongated plate-like measurement object 2 is fixed in a vertically extending state. . In this fixing, the base 12 side is firmly fixed by the fixtures 15 and 15, and the ceiling 14 side is
By being sandwiched between 6 and 16, it is supported in a state close to the free end. Then, the upper side of the measurement target 2 (the ceiling 1
The sensor 1 according to the first embodiment and the acceleration sensor 11 for comparison reference are fixed on a plane (close to 4).
Further, a notch 16 is provided on a deviated flat surface below the measurement object 2, for example, on a surface side on which the sensors 1 and 11 are fixed, in order to easily cause a crack. Then, this experimental device is fixed on the vibration table 17. The vibration table 17 vibrates horizontally along a direction in which each plane of the measurement object 2 faces (a thickness C direction described later).

In this experiment, the measurement object 2
For example, as shown in FIG.
A material having a thickness of 0 mm, a width B of 45 mm, and a thickness C of 6 mm is used. And, as the notch 16, a position 100 mm from the lower end of the measuring object 15 (D = 100 m
m), a concave groove having a width E = 5 mm and a depth F = 3 mm is provided horizontally (along the width B direction). Also, as the material of the measurement object 2, two kinds of materials, aluminum and steel, are prepared.

FIG. 1 shows the experimental results obtained by the configuration shown in FIG.
6 and FIG. FIG. 16 shows the measurement target 2 made of aluminum, and FIG. 17 shows the measurement target 2 made of steel. In this experiment, in both cases where the measurement object 2 was made of aluminum or steel, cracks occurred in the portions where the notches 16 were provided, and the cracks progressed. Broke. Each figure (a), the output V _g with respect to time change of the acceleration sensor 11, each figure (b) is an output V _j with respect to the time change of the sensor 1 according to the first embodiment. As seen from the figures, the output V _g In determination difficult discontinuities of the acceleration sensor 11, clearly appear in the output V _j of the sensor 1 according to the present embodiment. It is as described above that the discontinuity means the occurrence and progress of cracks in the measurement target object 2, which means that the AE (Ac
oustic Emission). Therefore, by using the sensor 1 according to the present embodiment, the occurrence and progress of the crack can be detected, and the progress of deterioration / damage of the measurement object 2 can be grasped. This process
For example, it can be realized by a computer, and the computer in this case corresponds to the displacement deriving means described in the claims, and processing by this computer corresponds to the displacement deriving process described in the claims.

In the first embodiment, the measurement of the angular velocity Ω due to the bending of the cantilever 4 is performed by using FIG.
Although the vibrating gyroscope 5 shown in FIG. 1 is used, other types of gyroscopes such as an optical fiber gyroscope and a coma gyroscope may be used. As long as the angular velocity Ω can be detected, a means other than the gyroscope, such as a means using an optical signal (light emitting means and light receiving means) and an optical mirror for reflecting the light signal, may be used.

Further, although the cantilever body 4 is used as a means for bending the acceleration a applied to the base portion 3, any other means may be used. However, if the cantilever 4 is used, the bending characteristics can be designed based on the above-mentioned Bernoulli-Eoiler's law, so that the sensor 1 suitable for a desired vibration frequency f can be easily designed.

Further, the first embodiment can also be applied to an active vibration damping (or vibration suppression) technique. That is, the vibration of the mechanical structure 2 is suppressed by detecting the vibration of the mechanical structure 2 by the sensor 1 and intentionally applying the vibration to the mechanical structure 2 based on the detection result. Such a technique can be performed using the acceleration sensor 11, but the sensor 1 according to the first embodiment captures the time derivative of the acceleration a.
Faster response is possible than when the acceleration sensor 11 is used. Of course, such an anti-vibration technique can be applied to the sound skip prevention of a generally known CD (compact disk) player, and the ABS (Anti-lock) of a car.
Brake System) It can also be applied to motion control in equipment. In order to apply vibration to the mechanical structure 2, for example, a generally known slide weight may be used, and a drive device such as a linear motor including the weight in this case may be used. Corresponds to vibration applying means. In order to control the driving device, as means for processing the output of the sensor 1, for example, a CPU or DS
P or the like may be used. In this case, the CPU or DSP
This corresponds to the vibration control means described in the claims.

Next, a second embodiment of the present invention will be described with reference to FIGS. Note that the second embodiment is based on the assumption that when a mechanical structure to be measured vibrates, a change in the amount of bending generated in the mechanical structure itself, for example, a change in curvature or radius of curvature is detected. That is, Claims 10 to 1 of the present invention
9 embodies the nine inventions.

FIG. 18 shows a schematic configuration of the second embodiment. As shown in the figure, in the second embodiment, a plurality of, for example, two angular velocity sensors 21 and 22 are mounted on one surface of a measurement object 20 which is curved by the vibration. As the angular velocity sensors 21 and 22, for example, the vibrating gyroscope 5 shown in FIG. 2 is used, which is attached according to the directions indicated by xyz coordinates in FIG.

For example, now, as shown in FIG.
It is assumed that a crack 23 has occurred between the angular velocity sensors 21 and 22 on the other surface of the measurement object 20.
In this state, vibration is applied to the measuring object 20, thereby, for example, as shown in FIG.
Are curved so that the other surface side protrudes. In this case, the measurement object 20 is more greatly curved than when the crack 23 does not occur. Therefore, crack 23
If the presence or absence of is not known, the magnitude of this curvature, for example, a change in the curvature 1 / ρ is detected, and this is compared with a normal value to determine the ratio or difference. It can be detected whether or not the crack 23 or the like has been damaged, and if so, the progress of the damage can be grasped.

Therefore, in the second embodiment, a change in the curvature 1 / ρ is detected from the outputs of the angular velocity sensors 21 and 22. That is, the angular velocity acts on each of the angular velocity sensors 21 and 22 when the measurement object 20 is curved. Accordingly, by detecting each angular velocity by each of the angular velocity sensors 21 and 22, each angular velocity of the measurement target 20 is determined based on a state where no vibration is applied to the measurement target 20 as shown in FIG. A change in each bending angle in a portion where the sensors 21 and 22 are provided can be detected. Then, if the difference between the changes in the respective bending angles is obtained, the change in the curvature 1 / ρ between the portions where the angular velocity sensors 21 and 22 of the measuring object 20 are provided can be detected.

However, according to the configuration of FIG. 18, it is necessary to previously store the amount of change in the curvature 1 / ρ of the measuring object 20 when no crack 23 or the like occurs, as described above. Therefore, as shown in FIG. 19, three or more, for example, three angular velocity sensors 30, 31, 32 are arranged in a substantially straight line. Then, the amounts of change of the curvatures 1 / ρ between the adjacent angular velocity sensors 30 and 31 and between the adjacent angular velocity sensors 31 and 32 are compared. From this comparison result, it is possible to detect whether or not the crack 23 or the like has been damaged in the measurement target object 20, and if so, the progress of the damage can be grasped.
When the crack 23 does not occur, the amount of change in the curvature 1 / ρ between the angular velocity sensors 30 and 31 and between the angular velocity sensors 31 and 32 is substantially constant.

Using the technique shown in FIG. 19, an experiment was conducted to monitor the progress of the crack 23. FIG. 20 shows a schematic configuration of the experimental apparatus. As shown in the figure, this experimental apparatus has a base 40 and a ceiling 4 supported by four columns 41, 41,.
The elongated plate-shaped measurement target 20 is fixed between the ceiling 42 and the base 40 so as to extend vertically. In this fixing, the base 40 side is firmly fixed by the fixing tools 43, 43, and the ceiling 42 side is supported in a state close to the free end by being sandwiched between the rubbers 40, 40. FIG. 21 shows details of the measurement object 20.
Shown in

As shown in the figure, the measuring object 20 has a length A ′ of A ′ = 550 mm, a width B ′ of B ′ = 45 mm,
The thickness C 'is C' = 10 mm. Then, on one side of a position 50 mm from the lower end (Q = 50 mm),
The angular velocity sensor 32 is fixed, and each angular velocity sensor 3 is moved upward from the sensor 33 at predetermined intervals P = 50 mm.
1, 30 are mounted in a straight line. In the width B direction of the measuring object 20, each of the angular velocity sensors 3
Attach 0, 31, 32. The mounting directions of the angular velocity sensors (vibrating gyroscopes) 30, 31, and 32 are as shown by the coordinate axes in FIG. Then, a concave notch 23a having a width E ′ = 5 mm and a depth F ′ = 5 mm is horizontally (in the width B direction) provided on the other surface side at a position 75 mm (D ′ = 100 mm) from the lower end of the measurement target 20. Along with the cracks 23 (that is, between the angular velocity sensors 31 and 32). Note that aluminum is used as the material of the measurement target 20.

Then, the experimental apparatus configured as described above is fixed on the vibration table 45. The vibration table 45 vibrates horizontally along the direction in which the planes of the measurement target 20 face each other (the direction of the thickness C of the measurement target 20).

FIG. 2 shows the results of the experiment using the configuration shown in FIG.
2 to 24. Among them, FIG. 22 is a diagram showing a change over time of a change in the curvature 1 / ρ _A of the measurement object 20 between the outputs of the angular velocity sensors 30 and 31 between the two. As shown in FIG.
Between 1 for cracks does not occur, the variation of the curvature 1 / [rho _A between these two is constant.

On the other hand, since the cracks 23 occur between the angular velocity sensors 31 and 32, the variation level of the curvature 1 / ρ _B of the measurement object 20 between the two is, as shown in FIG. Increase over time.
The increase in the fluctuation level of the curvature 1 / ρ _B is caused by the notch 23a
Indicates that the crack 23 has occurred or that the crack 23 has developed. Therefore, this curvature 1 /
From the temporal change of the [rho _A, you can grasp the occurrence or progress of cracks 23.

FIG. 24 shows the angular velocity sensors 30 and 31 described above.
A reference curvature 1 / [rho _A between the ratio of the curvature 1 / [rho _B between each of the angular velocity sensor 31 and 32 P (i.e. ρ _B / ρ _A). Thus, the progress of the crack 23 can be grasped also from the curvature ratio P. The processes shown in FIGS. 22 to 24 can be realized by, for example, a computer. The computer in this case corresponds to the displacement deriving means described in the claims, and the processing process corresponds to the displacement deriving process described in the claims.

In FIG. 23, the curvature 1 / ρ _B
The change in the step changes stepwise for the following reason.
That is, in this experiment, in order to promote the propagation of the cracks 23, the vibration frequency f of the vibration table 45 was manually adjusted so as to intentionally match the natural frequency f _P of the measurement object 20. Because the adjustment at that time was stepwise,
The change in the variation of the curvature 1 / ρ _B also became stepwise.
In addition, the natural frequency f _P of the measurement target 20 decreases as the crack 23 evolves (elapse of time t), as shown in FIG.

In the second embodiment, each of the angular velocity sensors 30, 31, and 32 has the configuration of the vibration gyro 5 shown in FIG. 2, but other angular velocity detecting means may be used. In addition, each angular velocity sensor 30, 31,
Although 32 is attached to one surface side of the measurement target 20, a part of them may be attached to the other surface side.

Then, also in the second embodiment,
Application to the above-mentioned active vibration isolation technology is possible.
In this case, anti-vibration control is performed based on the curvature 1 / ρ of the measurement object 20. As in the first embodiment, this control is also performed by a driving device (vibration applying unit) including, for example, a slide weight, and a CPU, a DSP, and the like (vibration control unit) for controlling the driving device. realizable.

[0104]

As described above, according to the present invention, it is possible to realize a so-called jerk sensor for directly detecting a jerk value generated in a mechanical structure due to, for example, generation or propagation of the crack. Further, it is possible to realize a sensor that detects a change in the bending generated in the mechanical structure itself due to the vibration of the mechanical structure over a relatively wide range.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a first embodiment of the present invention.

FIG. 2 is a diagram of a vibration gyroscope alone, which is an example of an angular velocity detecting unit in FIG. 1, (a) is an external perspective view,
(B) is a plan view.

FIG. 3 is an experimental configuration diagram for measuring characteristics and operation of a single sensor of FIG. 1;

FIG. 4 is a diagram showing measurement results according to FIG. 3, and is a characteristic diagram showing sensitivity to acceleration with respect to frequency.

FIG. 5 is a graph showing measurement results according to FIG. 3, and is a characteristic diagram showing jerk sensitivity with respect to frequency.

FIG. 6 is a graph showing experimental results according to FIG. 3, and is a characteristic diagram of a magnitude of a sensor output with respect to a magnitude of a jerk input at a constant frequency.

7 is an actual configuration diagram for measuring an impulse response characteristic of the sensor of FIG.

8A and 8B are diagrams showing measurement results according to FIG. 7, wherein FIG. 8A is an output characteristic diagram of an acceleration sensor, and FIG. 8B is an output characteristic diagram of a jerk sensor.

9 is a spectrum diagram obtained by frequency-analyzing the measurement result in FIG.

10A and 10B are diagrams showing measurement results according to FIG. 3, wherein FIG. 10A is an output operation diagram of the acceleration sensor, and FIG. 10B is an output operation diagram of the jerk sensor.

11 is a spectrum diagram obtained by frequency analysis of the measurement result in FIG.

FIGS. 12A and 12B are diagrams showing the results of an experiment performed under conditions different from those in FIGS. 10A and 10B. FIG. 12A is an output operation diagram of an acceleration sensor, and FIG. 12B is an output operation diagram of a jerk sensor.

FIG. 13 is a spectrum diagram obtained by frequency analysis of the measurement result in FIG.

FIG. 14 is a measurement evaluation diagram in the first embodiment,
It is a block diagram about the experiment which monitors the progress of the crack of a mechanical structure.

FIG. 15 is a detailed view of an object to be measured in FIG. 5;

FIGS. 16A and 16B are diagrams showing experimental results according to FIG. 14, wherein FIG. 16A is an output characteristic diagram of an acceleration sensor, and FIG. 16B is an output characteristic diagram of a jerk sensor.

FIGS. 17A and 17B are diagrams showing experimental results of FIG. 14 with respect to a measuring object made of a material different from that of FIG. 16, wherein FIG. 17A is an output characteristic diagram of an acceleration sensor, and FIG. .

FIG. 18 is a diagram illustrating a schematic configuration of a second embodiment of the present invention.

FIG. 19 is a diagram showing another example different from FIG. 18;

FIG. 20 is a measurement evaluation diagram in the second embodiment,
It is a block diagram about the experiment which monitors the progress of the crack of a mechanical structure.

21 is a detailed view of the measurement target in FIG.

FIG. 22 is a view showing an experimental result according to FIG. 20;

FIG. 23 is a diagram showing an experimental result according to FIG. 20, which is a measurement result of a target portion different from that of FIG. 22;

FIG. 24 is a diagram showing an experimental result according to FIG. 20, and is a diagram showing a ratio between FIG. 21 and FIG. 22;

FIG. 25 is a diagram showing a process of adjusting the experimental apparatus in the experiment process shown in FIG. 20;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Jerk sensor 2 Mechanical structure 3 Base part 4 Cantilever 5 Vibration gyroscope

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G01P 9/04 G01P 9/04 G05D 19/00 G05D 19/00

Claims (19)

[Claims] 1. A base portion attached to a surface of a mechanical structure to be measured, and a portion fixed to the base portion and fixed to the base portion when the mechanical structure vibrates along a predetermined direction. A deformed portion having a bent portion that bends in a direction along the vibration direction with a base point as a base,
A dynamic quantity sensor provided at a position separated from the portion of the deformed portion fixed to the base portion via the bending portion at a predetermined interval, and detecting angular velocity at the position. 2. The cantilever body according to claim 2, wherein the deformable portion is a cantilever extending in a direction intersecting with the vibration direction, and one end of the cantilever is fixed to the base. The physical quantity sensor according to claim 1, wherein the angular velocity detecting means is provided on the other end of the body. 3. The mechanical quantity sensor according to claim 2, wherein a frequency at which the cantilever resonates with the vibration is set higher than an actual vibration frequency of the mechanical structure. 4. The mechanical quantity sensor according to claim 2, wherein a frequency at which the cantilever resonates with the vibration is set near an actual vibration frequency of the mechanical structure. 5. The physical quantity sensor according to claim 1, wherein said angular velocity detecting means is constituted by gyroscope means. 6. A displacement measuring device comprising: the physical quantity sensor according to claim 1; and a displacement deriving unit that derives a displacement of the mechanical structure itself due to the vibration based on an output of the physical quantity sensor. 7. A mounting process for attaching a mechanical quantity sensor for detecting a mechanical quantity generated in a mechanical structure when the mechanical structure to be measured vibrates along a predetermined direction to the mechanical structure; A displacement deriving step of deriving a displacement of the mechanical structure itself based on an output of the quantity sensor, wherein the mechanical quantity sensor is used as the mechanical quantity sensor.
A displacement measuring method using the physical quantity sensor according to 1. 8. A mechanical quantity sensor according to claim 1, vibration applying means for applying a vibration along said predetermined direction to said mechanical structure according to a vibration control signal, and said machine based on an output of said physical quantity sensor. A vibration control unit that generates the vibration control signal in a state where the vibration of the structure itself is suppressed and supplies the vibration control signal to the vibration applying unit. 9. A mounting process for attaching a mechanical quantity sensor for detecting a mechanical quantity generated in a mechanical structure when the mechanical structure to be measured vibrates along a predetermined direction to the mechanical structure; A condition deriving process for deriving a vibration condition necessary for suppressing the vibration of the mechanical structure itself by giving a vibration along the predetermined direction to the mechanical structure based on the output of the quantity sensor; And applying a vibration to the mechanical structure in accordance with the vibration conditions derived and obtained in the process. 3. A vibration control method comprising: using the physical quantity sensor according to claim 1 as the physical quantity sensor. Method. 10. When the mechanical structure to be measured vibrates to cause the mechanical structure to bend, the predetermined surface is provided at a plurality of positions on the surface along the predetermined surface of the mechanical structure. Angle detecting means for detecting bending angles with respect to the predetermined surface at a plurality of locations which are spaced apart from each other by a predetermined distance in a direction along the direction, and any of the bending angles at the respective locations obtained by the angle detecting means. The relative difference between the deflection angles at the two positions of
A bending amount deriving unit that derives a bending amount of the mechanical structure between portions. 11. The physical quantity sensor according to claim 10, wherein each of the locations is three or more and is located substantially in a straight line. 12. The physical quantity sensor according to claim 10, wherein said angle detecting means is a plurality of angular velocity detecting means arranged at each of said locations. 13. The physical quantity vibration sensor according to claim 12, wherein said angular velocity detecting means is constituted by gyroscope means. 14. The physical quantity sensor according to claim 10,
The storage means in which the output of the physical quantity sensor for the vibration when the mechanical structure is normal is stored in advance, and the storage content stored in the storage means is compared with the output of the physical quantity sensor. And a displacement deriving means for deriving a displacement of the mechanical structure itself due to the vibration. 15. The physical quantity sensor according to claim 11,
A displacement deriving means for deriving a displacement of the mechanical structure itself due to the vibration by comparing the amount of deflection between two or more of the two locations where the combination of the locations is different among outputs of the dynamic quantity sensor. Measuring device. 16. A mounting process for mounting a mechanical quantity sensor for detecting a mechanical quantity generated in a mechanical structure when the mechanical structure to be measured vibrates, when the mechanical structure is normal. Storing the output of the mechanical quantity sensor with respect to the vibration in advance, and comparing the contents stored in the storing step with the output of the mechanical quantity sensor to derive the displacement of the mechanical structure itself due to the vibration. And a displacement deriving process, comprising:
A displacement measuring method using the physical quantity sensor according to claim 10 as the physical quantity sensor. 17. A mounting process for attaching a mechanical quantity sensor, which detects a mechanical quantity generated in each of a plurality of different portions on the mechanical structure when the mechanical structure to be measured vibrates, to the mechanical structure; A displacement deriving step of comparing each output of the physical quantity sensor relating to each part on the mechanical structure with each other to derive a displacement of the mechanical structure itself due to the vibration, and
A displacement measuring method using the physical quantity sensor according to claim 11 as the physical quantity sensor. 18. The physical quantity sensor according to claim 10,
Vibration applying means for applying vibration to the mechanical structure according to a vibration control signal; and the vibration applying means for generating the vibration control signal in a state in which bending of the mechanical structure itself is suppressed based on an output of the physical quantity sensor. And a vibration control means for supplying the vibration control device to the vehicle. 19. A mechanical quantity sensor for detecting a mechanical quantity generated in a mechanical structure to be measured when the mechanical structure to be measured vibrates is attached to the mechanical structure, based on an output of the mechanical quantity sensor. A condition deriving process for deriving a vibration condition necessary for suppressing the deflection of the mechanical structure itself by applying vibration to the mechanical structure, and the machine according to the vibration condition derived and derived in the condition deriving process. 11. A vibration damping method comprising: a vibration imparting step of giving a vibration to a structure, wherein the physical quantity sensor according to claim 10 is used as the physical quantity sensor.