阅读说明：本技术 检测系统和检测方法 (Detection system and detection method ) 是由 入江贵彦 稻本繁典 上田健太 于 2018-03-29 设计创作，主要内容包括：检测系统(1)包括传感设备(10)和检测处理设备(20),其中,该传感设备(10)具备：振动单元(11),其安装于检查对象(100),用于对检查对象(100)施加振动；驱动电路(12),其用于向振动单元(11)提供用于驱动振动单元(11)的电信号；以及传感器(13),其用于检测通过从振动单元(11)施加的振动使检查对象(100)产生的振动,该检测处理设备(20)用于从传感设备(10)接收与由传感器(13)检测出的检查对象(100)的振动有关的振动信息,并基于振动信息来检测检查对象(100)的状态变化。振动单元(11)具备线圈(112)、弹簧(113)以及磁体(114b)。(The detection system (1) comprises a sensing device (10) and a detection processing device (20), wherein the sensing device (10) is provided with: a vibration unit (11) attached to the inspection object (100) and configured to apply vibration to the inspection object (100); a drive circuit (12) for supplying an electric signal for driving the vibration unit (11) to the vibration unit (11); and a sensor (13) for detecting vibration generated by the inspection object (100) by the vibration applied from the vibration unit (11), the detection processing device (20) being configured to receive vibration information relating to the vibration of the inspection object (100) detected by the sensor (13) from the sensing device (10) and detect a change in state of the inspection object (100) based on the vibration information. The vibration unit (11) is provided with a coil (112), a spring (113), and a magnet (114 b).)

1. A detection system for detecting a change of state of an examination object, the detection system being characterized in that,

Comprises a sensing device and a detection processing device, wherein,

The sensing device is provided with: a vibration unit mounted on the inspection object for applying vibration to the inspection object; a driving circuit for supplying an electric signal for driving the vibration unit to the vibration unit; and a sensor for detecting vibration generated to the inspection object by the vibration applied from the vibration unit,

The detection processing device is configured to receive vibration information about the vibration of the inspection object detected by the sensor from the sensing device and detect the state change of the inspection object based on the vibration information,

The vibration unit of the sensing device includes: a coil through which the electric signal supplied from the driving circuit flows; a spring provided in a vibratable manner; and a magnet attached to the spring and disposed so as to be separated from the coil.

2. The detection system of claim 1,

The detection processing apparatus calculates a resonance frequency of the vibration of the inspection object from the vibration information, and detects the state change of the inspection object based on an amount of change in the resonance frequency.

3. The detection system of claim 2,

The detection processing apparatus includes a storage section for storing the resonance frequency of the vibration of the inspection object,

The detection processing device compares the calculated resonance frequency of the vibration of the examination subject with the resonance frequency of the vibration of the examination subject stored in advance in the storage unit to calculate the amount of change in the resonance frequency, and detects the state change of the examination subject when the amount of change in the resonance frequency is equal to or greater than a predetermined threshold value.

4. Detection system according to any one of claims 1 to 3,

The drive circuit is configured to supply any one of a pulse signal, a sweep signal, and a random signal to the vibration unit as the electric signal.

5. The detection system according to any one of claims 1 to 4,

The sensor is an acceleration sensor attached to the inspection object or a laser sensor disposed so as to be separated from the inspection object.

6. detection system according to one of claims 1 to 5,

The detection system comprises a plurality of said sensing devices,

The detection processing device receives the vibration information relating to the vibration of the inspection object from each of the plurality of sensing devices.

7. A detection method for detecting a change in state of an inspection object, the detection method comprising:

supplying an electric signal from a driving circuit to a vibration unit mounted to the inspection object to drive the vibration unit, thereby applying vibration to the inspection object;

Detecting, using a sensor, a vibration generated by the inspection object by the vibration applied from the vibration unit; and

detecting, using a processor, the state change of the inspection object based on the vibration of the inspection object detected by the sensor,

Wherein the vibration unit includes: a coil through which the electric signal supplied from the driving circuit flows; a spring provided in a vibratable manner; and a magnet attached to the spring and disposed so as to be separated from the coil.

Technical Field

The present invention relates generally to a detection system and a detection method, and more particularly, to a detection system and a detection method for vibrating an inspection object by applying vibration to the inspection object and detecting a change in state of the inspection object by analyzing the vibration of the inspection object.

Background

Conventionally, in order to detect a change in the state of an inspection object such as a pillar of a building or a concrete structure, the inspection object is vibrated, and the vibration of the inspection object is detected and analyzed. Since the resonance (natural) frequency of the vibration of the test object changes when the test object changes in state, such as due to failure or deterioration, the change in state of the test object can be detected by analyzing the vibration of the test object.

For example, patent document 1 discloses a frequency measuring apparatus including a vibrator having a pulse hammer (impulse hammer) made of a hard material for applying an impact to an inspection object, and a sensor for detecting vibration generated in the inspection object by the impact applied by the vibrator. When the state of the inspection target changes due to continuous deterioration, failure, or the like, the mass and the spring constant of the inspection target change, and thus the resonance frequency of the vibration of the inspection target changes. By using the frequency measurement device disclosed in patent document 1, a change in the resonance frequency of the vibration of the test object can be detected, and as a result, a change in the state of the test object can be detected.

However, when the object to be inspected is vibrated using a vibrator having a pulse weight as disclosed in patent document 1, the vibrator needs to be formed of a material having high impact resistance. Such materials are generally heavy. In addition, in order to sufficiently vibrate the inspection object, a large impact needs to be applied to the inspection object, and thus the pulse hammer itself needs to be heavy and large. Therefore, there is a problem that the apparatus is increased in weight and size.

Patent document 2 discloses an abnormality detection system including a vibrator having a pulse hammer or a piezoelectric element (piezoelectric element) made of a hard material and configured to vibrate an inspection object, and a sensor configured to detect vibration generated in the inspection object by an impact applied by the pulse hammer or vibration of the piezoelectric element. When the test object is vibrated by using a pulse hammer, the same problem as that of the above-mentioned patent document 1 occurs. On the other hand, when the test object is vibrated by using the piezoelectric element, a high input voltage needs to be applied to the piezoelectric element in order to vibrate the test object sufficiently. Therefore, there is a problem in that the amount of electric power required for the abnormality detection system increases.

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to simplify, reduce the size of, and save power for a detection system that can detect a change in the state of an inspection target by detecting and analyzing vibration generated in the inspection target by applying the vibration to the inspection target.

Means for solving the problems

The above object is achieved by the present invention according to the following (1) to (7).

(1) A detection system for detecting a change of state of an examination object, the detection system being characterized in that,

Comprises a sensing device and a detection processing device, wherein,

The sensing device is provided with: a vibration unit mounted on the inspection object for applying vibration to the inspection object; a driving circuit for supplying an electric signal for driving the vibration unit to the vibration unit; and a sensor for detecting vibration generated to the inspection object by the vibration applied from the vibration unit,

The detection processing device is configured to receive vibration information about the vibration of the inspection object detected by the sensor from the sensing device and detect the state change of the inspection object based on the vibration information,

the vibration unit of the sensing device includes: a coil through which the electric signal supplied from the driving circuit flows; a spring provided in a vibratable manner; and a magnet attached to the spring and disposed so as to be separated from the coil.

(2) According to the detection system recited in the above (1), the detection processing device calculates a resonance frequency of the vibration of the inspection object from the vibration information, and detects the state change of the inspection object based on an amount of change in the resonance frequency.

(3) The detection system according to the above (2), wherein the detection processing device includes a storage section for storing the resonance frequency of the vibration of the inspection object,

The detection processing device compares the calculated resonance frequency of the vibration of the examination subject with the resonance frequency of the vibration of the examination subject stored in advance in the storage unit to calculate the amount of change in the resonance frequency, and detects the state change of the examination subject when the amount of change in the resonance frequency is equal to or greater than a predetermined threshold value.

(4) According to the detection system described in any one of the above (1) to (3), the drive circuit is configured to supply any one of a pulse signal, a sweep signal, and a random signal to the vibration unit as the electric signal.

(5) The detection system according to any one of the above (1) to (4), wherein the sensor is an acceleration sensor attached to the inspection object or a laser sensor disposed so as to be separated from the inspection object.

(6) The detection system according to any one of the above (1) to (5), comprising a plurality of the sensing devices,

The detection processing device receives the vibration information relating to the vibration of the inspection object from each of the plurality of sensing devices.

(7) A detection method for detecting a change in state of an inspection object, the detection method comprising:

Supplying an electric signal from a driving circuit to a vibration unit mounted to the inspection object to drive the vibration unit, thereby applying vibration to the inspection object;

Detecting, using a sensor, a vibration generated by the inspection object by the vibration applied from the vibration unit; and

Detecting, using a processor, the state change of the inspection object based on the vibration of the inspection object detected by the sensor,

Wherein the vibration unit includes: a coil through which the electric signal supplied from the driving circuit flows; a spring provided in a vibratable manner; and a magnet attached to the spring and disposed so as to be separated from the coil.

ADVANTAGEOUS EFFECTS OF INVENTION

In the detection system and the detection method of the present invention, a VCM (Voice Coil Motor) type vibration unit is used as a vibrator for vibrating an inspection object, and the VCM type vibration unit includes: a coil through which an electric signal supplied from a driving circuit flows; a spring provided in a vibratable manner; and a magnet attached to the spring and disposed so as to be separated from the coil. Therefore, it is not necessary to form the vibration unit (vibrator) with a material having high impact resistance as in the conventional art using a pulse hammer. Further, since the VCM type vibration unit can generate large vibration at a relatively low input voltage, it is not necessary to apply a high input voltage to the vibration unit as in the conventional technique using a piezoelectric element. Therefore, according to the present invention, simplification, downsizing, and power saving of the detection system can be achieved.

Drawings

Fig. 1 is a conceptual diagram illustrating a detection system according to a first embodiment of the present invention.

Fig. 2 is a perspective view of the vibration unit shown in fig. 1.

Fig. 3 is an exploded perspective view of the vibration unit shown in fig. 1.

Fig. 4 is a sectional view of the vibration unit shown in fig. 1.

Fig. 5 is a diagram showing an example of vibration generated in the inspection object when any of the pulse signal, the sweep signal, and the random signal is supplied to the vibration unit shown in fig. 1.

Fig. 6 is a diagram showing another example of vibration generated in the inspection object when any of the pulse signal, the sweep signal, and the random signal is supplied to the vibration unit shown in fig. 1.

Fig. 7 is a diagram for explaining a change in the characteristics of vibration generated in the inspection target due to a change in the mass of the inspection target shown in fig. 1.

Fig. 8 is a conceptual diagram illustrating a detection system according to a second embodiment of the present invention.

Fig. 9 is a conceptual diagram illustrating a detection system according to a third embodiment of the present invention.

Fig. 10 is a flow chart illustrating the detection method of the present invention.

Detailed Description

The detection system and the detection method of the present invention will be described below based on preferred embodiments shown in the drawings. First, a detection system according to a first embodiment of the present invention will be described in detail with reference to fig. 1 to 7.

< first embodiment of detection System >

Fig. 1 is a conceptual diagram illustrating a detection system according to a first embodiment of the present invention. Fig. 2 is a perspective view of the vibration unit shown in fig. 1. Fig. 3 is an exploded perspective view of the vibration unit shown in fig. 1. Fig. 4 is a sectional view of the vibration unit shown in fig. 1. Fig. 5 is a diagram showing an example of vibration generated in the inspection object when any of the pulse signal, the sweep signal, and the random signal is supplied to the vibration unit shown in fig. 1. Fig. 6 is a diagram showing another example of vibration generated in the inspection object when any of the pulse signal, the sweep signal, and the random signal is supplied to the vibration unit shown in fig. 1. Fig. 7 is a diagram for explaining a change in the characteristics of vibration generated in the inspection target due to a change in the mass of the inspection target shown in fig. 1.

The detection system 1 shown in fig. 1 comprises: a sensing device 10 for applying vibration to the inspection object 100 and detecting vibration generated by the inspection object 100 by the vibration; and a detection processing device 20 for detecting a change in state of the inspection object 100 based on vibration information about vibration of the inspection object 100 received from the sensing device 10.

The sensing device 10 has a function of applying vibration to the inspection object 100 and detecting vibration generated by the inspection object 100 by the vibration. The sensor device 10 includes: a vibration unit 11 attached to the inspection object 100 for applying vibration to the inspection object 100; a drive circuit 12 for supplying an electric signal for driving the vibration unit 11 to the vibration unit 11; a sensor 13 for detecting vibration generated to the inspection object 100 by the vibration applied from the vibration unit 11; and a communication section 14 for communicating with the detection processing device 20.

the vibration unit 11 is attached to the inspection object 100 to vibrate the inspection object 100 according to the electric signal supplied from the drive circuit 12. As shown in fig. 2 to 4, the vibration unit 11 is a VCM (Voice Coil Motor) type vibration unit having a small size (for example, a height of 30mm × a vertical width of 30mm × a horizontal width of 30mm), and constitutes one resonance system.

The vibration unit 11 includes: a housing 111 configured to be attachable to the inspection object 100; a coil 112 fixedly provided on the bottom surface of the case 111, through which coil 112 an electric signal supplied from the drive circuit 12 flows; a spring 113 provided so as to be capable of vibrating with respect to the housing 111; and a magnet assembly 114 attached to the spring 113 and disposed apart from the coil 112.

The housing 111 is a cylindrical member, and has a function of fixing the vibration unit 11 as a vibration body and housing each component of the vibration unit 11. The housing 111 includes a cover 111a, a base 111b, and a cylindrical portion 111c located between the cover 111a and the base 111 b.

Three extending portions extending in the radial direction of the base 111b are formed on the outer peripheral surface of the base 111b, and through holes 111d are formed on the tip sides of the three extending portions, respectively. A screw, not shown, is inserted through the through hole 111d of the base 111b and screwed into a screw hole formed in the inspection object 100. This enables the base 111b to be fixed to the inspection object 100, and the vibration unit 11 to be attached (fixed) to the inspection object 100. By attaching the vibration unit 11 to the inspection object 100, the vibration of the vibration unit 11 can be transmitted to the inspection object 100, and the inspection object 100 can be vibrated.

The coil 112 has a cylindrical shape and is fixedly provided on the base 111 b. Both ends (electric signal supply ends) of the coil 112 are connected to the drive circuit 12, and an electric signal supplied from the drive circuit 12 flows in the coil 112. As shown in fig. 4, in the assembled state of the vibration unit 11, the coil 112 is positioned inside the central opening of the spring 113.

the spring 113 has a function of holding the magnet assembly 114 so as to be capable of vibrating with respect to the coil 112. The magnet 114 is attached to the spring 113, and when an electric signal supplied from the drive circuit 12 flows in the coil 112, a driving force that moves the magnet 114 attached to the spring 113 in the up-down direction in fig. 4 is generated. At this time, since the magnet assembly 114 is held by the spring 113 so as to be able to vibrate with respect to the coil 112, the magnet assembly 114 is able to vibrate with respect to the coil 112. The spring 113 is not particularly limited as long as the magnet assembly 114 can be held so as to be capable of vibrating with respect to the coil 112, and a leaf spring, a coil spring, a magnetic spring, or the like can be used as the spring 113, for example. For convenience of explanation, the spring 113 is a leaf spring as shown in fig. 3 and 4.

The spring 113 has a ring shape having a central opening portion, an outer peripheral portion of the spring 113 is held between the base 111b and the cylindrical portion 111c, and the central portion of the spring 113 including the central opening portion can vibrate with respect to the housing 111 in the vertical direction in fig. 4. The magnet assembly 114 is attached to a central portion of the spring 113 and can vibrate with respect to the coil 112.

As shown in fig. 4, the magnet assembly 114 includes: a magnet holding portion 114a having a cylindrical shape opened toward the lower side in fig. 4; a magnet 114b fixed to a central lower surface of the magnet holding portion 114 a; and a yoke 114c mounted on a lower surface of the magnet 114 b.

As shown in fig. 4, in a state where the vibration unit 11 is assembled, the magnet 114b and the yoke 114c are disposed in the central hollow portion of the coil 112 so as to be separated from the coil 112. When an electric signal is supplied from the drive circuit 12 to the coil 112, a driving force that moves the magnet assembly 114 (magnet 114b) in the up-down direction in fig. 4 is generated. The magnet assembly 114 is mounted on the spring 113 provided in a manner capable of vibrating, and therefore the magnet assembly 114 vibrates in the up-down direction.

In this way, when an electric signal is supplied from the drive circuit 12 to the coil 112 of the vibration unit 11 and the electric signal flows in the coil 112, the vibration unit 11 vibrates. The equation of motion representing the principle of operation of one resonance system such as the vibration unit 11 can be expressed by the following equation (1).

[ number 1]

Where m is the mass [ kg [)]and x (t) is the displacement [ m ] of the magnet assembly 114 (vibrator)]，K_fIs the thrust constant N/A of a resonant system]I (t) is the current [ A ] flowing in the coil 112]，K_spIs the spring constant [ N/m ] of the spring 113]D is the damping coefficient of a resonant system [ N/(m/s)]。

a circuit equation showing the operation principle of one resonance system such as the vibration unit 11 can be expressed by the following equation (2).

[ number 2]

Here, e (t) is the voltage [ V ] applied to the coil 112]And R is the resistance [ omega ] of the coil 112]L is the inductance [ H ] of the coil 112]，K_eIs the back electromotive force constant [ V/(m/s) of a resonant system]。

From such a motion equation and a circuit equation, the transfer function G (j ω) of the vibration unit 11 is derived as shown in the following equation (3), and exhibits a specific response to the electric signal supplied from the drive circuit 12.

[ number 3]

That is, the characteristics of the vibration unit 11 (the output of one resonance system) change depending on the kind of the electric signal (the input to one resonance system) supplied from the drive circuit 12 to the vibration unit 11. For example, fig. 5 shows an example of vibration of the inspection object 100 in the following case: a structure made of ABS (Acrylonitrile Butadiene Styrene) resin is used as the inspection object 100, and a pulse signal, a sweep signal, and a random signal are supplied to the vibration unit 11 attached to the inspection object 100, respectively, and the vibration unit 11 is vibrated by supplying the pulse signal, the sweep signal, and the random signal to the vibration unit 11. The resonance frequency f of the examination subject 100 in this example_rIs around 5 kHz.

as shown in fig. 5, when the pulse signal, the sweep signal, and the random signal are supplied to the vibration unit 11, the resonance frequency f of the inspection object 100 is set to be the same as the resonance frequency f_rNear 5kHz, the amplitude of the vibration of the inspection object 100 is maximum. Therefore, in the example shown in fig. 5, when any one of the pulse signal, the sweep signal, and the random signal is supplied to the vibration unit 11, the resonance frequency f of the vibration of the inspection object 100 can be detected_r. However, in the example shown in fig. 5, in the case where the pulse signal is supplied to the vibration unit 11It is apparent that the resonance frequency f of the examination object 100_rThe lower amplitude is the largest. As a result, it was found that the resonance frequency f of the inspection object 100 was detected with high accuracy_rIn other words, it is most appropriate to supply the pulse signal to the vibration unit 11.

On the other hand, fig. 6 shows an example of the vibration of the inspection object 100 in the following case: a case made of plastic is used as the inspection object 100, and a pulse signal, a sweep signal, and a random signal are supplied to the vibration unit 11 attached to the inspection object 100, respectively, and the vibration unit 11 is vibrated. The mass and the spring constant of the inspection object 100 in the example of fig. 6 are different from those of the inspection object 100 in the example of fig. 5. Resonance frequency f of the examination subject 100 in the example of fig. 6_rIs around 0.125 kHz.

As shown in fig. 6, in the case where the pulse signal is supplied to the vibration unit 11, the resonance frequency f of the inspection object 100 is set_rI.e. the maximum amplitude in the frequency band outside the vicinity of 0.125 kHz. On the other hand, in the case where the sweep signal or the random signal is supplied to the vibration unit 11, the resonance frequency f of the inspection object 100 is set_rI.e. maximum amplitude around 0.125 kHz. Therefore, in the example shown in fig. 6, when the pulse signal is supplied to the vibration unit 11, the resonance frequency f of the vibration of the inspection object 100 cannot be detected with high accuracy_r。

In this way, the kind of the electric signal supplied from the drive circuit 12 to the vibration unit 11 differs depending on the mass and the spring constant of the inspection object 100. As will be described later, since the drive circuit 12 is configured to supply any one of a pulse signal, a sweep signal, and a random signal to the vibration unit 11, the sensing device 10 can detect the resonance frequency f of the vibration of the various inspection objects 100_r。

As described above, when the vibration unit 11 attached to the inspection object 100 vibrates, the vibration is applied to the inspection object 100. When vibration is applied from the vibration unit 11 to the inspection object 100, the vibration of the inspection object 100 is excited. When the test object 100 vibrates, the resonance frequency f determined by the following formula (4)_rWhen the temperature of the water is higher than the set temperature,The inspection object 100 vibrates largely.

[ number 4]

Here, m₁Is the mass of the inspection object 100, m₂Is the mass of the vibration unit 11 mounted on the inspection object 100, K_spIs the spring constant of the inspection object 100.

as shown in the above equation (4), the resonance frequency f of the object 100_rDepending on the mass m of the examination object 100₁And spring constant K_spTherefore, when the state of the object 100, that is, the mass m is inspected due to the passage of time, a failure, or the like₁And spring constant K_spWhen changed, the resonant frequency f of the object 100_rChanges also occur.

FIG. 7 shows the mass m of the inspection object 100 due to the passage of time, failure, or the like_1aIncrease to m_1bResonance frequency f of the examination subject 100_rExamples of variations of (c). As shown in fig. 7, when the mass m of the object 100 is inspected₁From m_1aIncrease to m_1bThe resonance frequency f, which is the frequency at which the amplitude of the vibration of the test object 100 is maximum_rShifted to the low frequency side. On the contrary, when the mass m of the inspection object 100₁When reduced, the resonance frequency f of the examination object 100_rShifted to the high frequency side. Similarly, when the spring constant K of the inspection object 100_spWhen increased, the resonance frequency f of the examination object 100_rBiased toward high frequency side when the spring constant K of the object 100 to be inspected_spwhen reduced, the resonance frequency f of the examination object 100_rShifted to the low frequency side.

Thus, by detecting the resonance frequency f of the object 100 to be examined_rCan detect the mass m of the inspection object 100₁And spring constant K_spI.e., a change in the state of the inspection object 100.

Mass m of object 100 to be inspected due to passage of time, failure, or the like₁For example, the object 100 is enumerated byA metal member made of a metal material such as iron. When a part of the inspection object 100 peels off due to corrosion, weathering, or the like of the metal material generated with the passage of time, the mass m of the inspection object 100₁And decreases. On the other hand, the mass m of the inspection object 100 due to the passage of time, a failure, or the like₁In an additional example, the inspection object 100 is installed outdoors. When dust, sand, water, or the like accumulates on the inspection object 100 over time, the mass m of the inspection object 100₁And (4) increasing.

Spring constant K of object 100 to be inspected due to passage of time, failure, or the like_spAn example of the change is a case where the inspection object 100 is a structure formed by connecting a plurality of members. For example, when bolts or screws for connecting a plurality of members are loosened, or when a beam between the members is deflected, the spring constant K of the inspection object 100_spA change occurs. In addition, in the case where the inspection object 100 is a rim of a tire of a vehicle, the spring constant K of the inspection object 100 is loose due to the rim_spA change occurs. Further, when the inspection object 100 is a structure made of concrete and the inspection object 100 is cracked or broken due to passage of time, impact, or the like, the spring constant K of the inspection object 100_spChanges also occur.

Thus, by detecting the resonance frequency f of the object 100 to be examined_rCan detect the mass m of the inspection object 100₁And spring constant K_spI.e., a change in the state of the inspection object 100. Therefore, the inspection system 1 of the present invention can detect various phenomena such as corrosion and weathering of the inspection object 100, an increase in the amount of accumulated material accumulated on the inspection object 100, loosening of bolts and screws of the inspection object 100, bending of beams, loosening of rims, and occurrence of cracks and fractures in the inspection object 100 as described above.

Returning to fig. 1, the drive circuit 12 has a function of supplying an electric signal for driving (vibrating) the vibration unit 11 to the vibration unit 11. The drive circuit 12 is configured to: any one of the pulse signal, the sweep signal, and the random signal is supplied to the vibration unit 11 in accordance with the control data received from the detection processing device 20 via the communication section 14.

The sensor 13 has a function of detecting vibration generated in the inspection object 100 by the vibration applied from the vibration unit 11. Vibration information on the vibration of the inspection object 100 detected by the sensor 13 is transmitted to the detection processing device 20 via the communication unit 14. The vibration information transmitted from the sensor 13 to the detection processing device 20 is, for example, acceleration of vibration (motion) of the inspection object 100 or the like. By performing processing such as fourier transform on the vibration information, the amplitude (energy) of each frequency of the vibration of the inspection object 100 can be acquired.

The sensor 13 is not particularly limited as long as it can detect the vibration of the inspection object 100, and for example, an acceleration sensor or a laser sensor, which is attached to the inspection object 100 and detects the acceleration of the motion of the inspection object 100, can be used as the sensor 13; the laser sensor is provided separately from the inspection object 100, irradiates the inspection object 100 with laser light, and detects the movement of the inspection object 100 based on the laser light reflected from the inspection object 100.

The communication unit 14 has the following functions: communicates with the detection processing device 20, receives control data from the detection processing device 20, and transmits vibration information about the vibration of the inspection object 100 detected by the sensor 13 to the detection processing device 20. In the case where the sensing device 10 and the detection processing device 20 are connected in a wired manner, the communication section 14 communicates with the detection processing device 20 by wired communication. In a case where the sensor device 10 and the detection processing device 20 are not connected by wire, Communication with the detection processing device 20 is performed using a wireless Communication technology such as NFC (Near Field Radio Communication), Wi-Fi, Bluetooth (registered trademark), or the like.

The supply of power to each component of the sensor device 10 may be realized by a built-in power supply such as a battery built in the sensor device 10, or may be realized by an external power supply provided outside the sensor device 10 and connected to the sensor device 10 through a power supply line.

The detection processing device 20 has the following functions: control data is transmitted to the sensing device 10, and vibration information on the vibration of the inspection object 100 detected by the sensor 13 is received from the sensing device 10, and a change in the state of the inspection object 100 is detected based on the received vibration information.

The detection processing device 20 may be implemented as a single device, or may be implemented in any computing device such as a desktop computer, a laptop computer, a notebook personal computer, a workstation, a tablet computer, a mobile phone, a smartphone, a PDA, and a wearable terminal.

The detection processing device 20 includes: at least one processor 21, the at least one processor 21 performing control of the detection processing device 20; a memory 22 that stores data, programs, modules, and the like necessary for controlling the detection processing device 20; a resonance frequency calculation unit 23 for calculating the resonance frequency f of the vibration of the inspection object 100 based on the received vibration information_r(ii) a A storage unit 24 for storing a reference resonance frequency f of the vibration of the inspection object 100_refAnd/or the resonance frequency f calculated by the resonance frequency calculation unit 23_r(ii) a A coherence calculating part 25 for calculating coherence γ between the vibration of the vibration unit 11 of the sensing device 10 and the vibration of the inspection object 100²(ii) a A state change detection unit 26 for passing the resonance frequency f of the vibration of the test object 100 calculated by the resonance frequency calculation unit 23_rAnd the reference resonance frequency f in the storage unit 24_refor the resonance frequency f of the vibration of the previous test object 100 stored in the storage unit 24_rComparing them to detect a change in the state of the inspection object 100; a communication section 27 that communicates with the sensor device 10; and a data bus 28 for carrying out the transmission of data between the various components of the detection processing device 20.

The processor 21 performs control of the detection processing device 20 by transmitting various data and various instructions to and from the respective components via the data bus 28. In addition, the processor 21 can provide desired functions by using the respective components of the detection processing device 20. For exampleThe processor 21 can calculate the resonance frequency f of the vibration of the inspection object 100 based on the received vibration information by using the resonance frequency calculating unit 23_rBy using the coherence calculator 25, the coherence γ between the vibration of the vibration unit 11 of the sensing device 10 and the vibration of the inspection object 100 can be calculated²By using the state change detecting unit 26, the state change of the inspection object 100 can be detected.

The processor 21 transmits control data to the sensor device 10 via the communication unit 27 at predetermined intervals (for example, every hour, every day, every week, every month, and the like) to cause the sensor device 10 to measure the vibration of the inspection object 100. The control data sent from the processor 21 is used to determine which of the pulse signal, the frequency sweep signal and the random signal the drive circuit 12 of the sensing device 10 supplies to the vibration unit 11. The drive circuit 12 that receives the control data supplies any one of the pulse signal, the sweep signal, and the random signal to the vibration unit 11 in accordance with the control data, and drives the vibration unit 11.

The processor 21 is an arithmetic unit that executes arithmetic processing such as signal manipulation based on a computer-readable command, such as one or more microprocessors, microcomputers, microcontrollers, Digital Signal Processors (DSPs), Central Processing Units (CPUs), Memory Control Units (MCUs), graphic processing arithmetic processing units (GPUs), state machines, logic circuits, Application Specific Integrated Circuits (ASICs), or a combination thereof. In particular, the processor 21 is configured to retrieve computer-readable commands (e.g., data, programs, modules, etc.) stored in the memory 22 to perform signal manipulation and control.

The memory 22 is a volatile storage medium (e.g., RAM, SRAM, DRAM), a non-volatile storage medium (e.g., ROM, EPROM, EEPROM, flash memory, hard disk, optical disk, CD-ROM, Digital Versatile Disks (DVD), magnetic cassettes, magnetic tape, magnetic disk), or a removable or non-removable computer-readable medium comprising combinations thereof.

The resonance frequency calculation unit 23 has a function of calculating the resonance frequency f of the vibration of the inspection object 100 based on the vibration information received from the sensing device 10 via the communication unit 27_rThe function of (c). Specifically, the resonance frequency calculation unit 23 performs processing such as fourier transform on the received vibration information to calculate the amplitude (energy) of the vibration of the inspection object 100 for each frequency as shown in fig. 7. The resonance frequency calculation unit 23 determines the frequency having the highest amplitude (energy) as the resonance frequency f of the vibration of the test object 100_r。

The storage unit 24 stores a reference resonance frequency f of the vibration of the inspection object 100_refAnd/or the resonance frequency f calculated by the resonance frequency calculation unit 23_rAny nonvolatile recording medium (e.g., hard disk, flash memory). Reference resonance frequency f of vibration of the examination object 100_refIs the resonance frequency f of the vibration of the test object 100 when the test object 100 is in a normal state_rThe reference resonance frequency f is determined before the operation of the detection system 1_refAnd stored in the storage unit 24. In addition, each time the resonance frequency calculation unit 23 calculates the resonance frequency f_rThen, the resonance frequency f of the vibration of the inspection object 100 calculated by the resonance frequency calculating unit 23 is set to be higher than the predetermined value_rStored in the storage unit 24 as accumulated data. Such accumulated data can be used to track the state change of the inspection object 100 in time series, and thus can provide information useful for maintenance inspection of the inspection object 100. Such accumulated data may be transmitted to a manager or the like of the inspection target 100 as a report at predetermined intervals (for example, hourly, daily, weekly, monthly, or the like).

The storage unit 24 also stores previously acquired vibration information relating to the vibration of the vibration unit 11. The vibration information on the vibration of the vibration unit 11 includes at least vibration information on the vibration of the vibration unit 11 when the pulse signal is supplied to the vibration unit 11 by the drive circuit 12, vibration information on the vibration of the vibration unit 11 when the sweep signal is supplied, and vibration information on the vibration of the vibration unit 11 when the random signal is supplied. Such vibration information on the vibration of the vibration unit 11 is obtained by calculating the coherence γ between the vibration of the vibration unit 11 of the sensing device 10 and the vibration of the inspection object 100 by the coherence calculator 25, which will be described later²Information used in the process.

The coherence calculator 25 has the following functions: on the basis of the vibration information on the vibration of the vibrating unit 11 of the sensing device 10 held in the storage unit 24 and the vibration information on the vibration of the inspection object 100 received from the sensing device 10, the coherence γ between the vibration of the vibrating unit 11 of the sensing device 10 and the vibration of the inspection object 100 is calculated². Specifically, the coherence calculator 25 calculates a coherence value between the vibration of the vibration unit 11 of the sensing device 10 and the vibration of the inspection object 100 by the following expression (5).

[ number 5]

Here, W_xxThe power spectrum of the input vibration, that is, the power spectrum of the vibration unit 11 is calculated from the vibration information about the vibration of the vibration unit 11 of the sensing device 10 stored in the storage unit 24. W_yyIs a power spectrum of the output vibration, that is, a power spectrum of the vibration of the inspection object 100. W_xyIs a cross spectrum (cross spread) of the vibration unit 11 and the vibration of the inspection object 100.

The coherence γ described above²Indicating the magnitude of the input vibration in relation to the output vibration. By reference to such coherence y²Can determine whether or not resonance of the test object 100 is excited by the vibration of the vibration unit 11. Coherency gamma²The closer to 1, the more efficiently the resonance of the inspection object 100 is excited by the vibration of the vibration unit 11, and the coherence γ is expressed²the smaller the size, the less the resonance of the test object 100 can be excited by the vibration of the vibration unit 11.

Such coherence γ²Less than 0.5 means that the inspection object 100 does not sufficiently resonate (vibrate). In this manner, the coherence γ calculated by the coherence calculator 25 is referred to²It is possible to determine whether or not the inspection object 100 has sufficiently vibrated. The processor 21 calculates the coherence γ from the coherence calculated by the coherence calculator 25²To change the control data. For example, the coherence γ is set when the pulse signal is supplied from the drive circuit 12 to the vibration unit 11²If the pulse signal is less than 0.5, the processor 21 determines that the resonance of the vibration unit 11 cannot be excited even if the pulse signal is supplied to the vibration unit 11. After that, the processor 21 changes the control data so that the drive circuit 12 supplies the sweep signal or the random signal to the vibration unit 11, and transmits the changed control data to the drive circuit 12 via the communication section 27.

The state change detection unit 26 has the following functions: by using the resonance frequency f of the vibration of the object 100 calculated by the resonance frequency calculating unit 23_rAnd the reference resonance frequency f in the storage unit 24_refOr the resonance frequency f of the vibration of the previous test object 100 stored in the storage unit 24_rA comparison is made to detect a change in the state of the inspection object 100. Specifically, the state change detection unit 26 calculates the resonance frequency f calculated by the resonance frequency calculation unit 23_rAnd the reference resonance frequency f stored in the storage unit 24_refOr previous resonance frequency f_rThe difference between them, and the absolute value of the calculated difference, i.e., the resonance frequency f_rWhether or not the amount of change in (c) is equal to or greater than a predetermined threshold value. The predetermined threshold value is appropriately determined depending on factors such as the size, structural material, and shape of the inspection object 100.

Is judged as the absolute value (resonance frequency f) of the calculated difference_rThe amount of change of (b) is equal to or greater than a predetermined threshold value, the state change detection unit 26 detects a state change of the inspection object 100. On the other hand, the absolute value (resonance frequency f) of the calculated difference is determined_rThe amount of change of (b) is smaller than a predetermined threshold value, the state change detection unit 26 detects that there is no state change of the inspection object 100. After that, the processor 21 executes processing according to the detection result of the state change detecting unit 26. For example, when a change in the state of the inspection object 100 is detected, the processor 21 transmits the detection to a user device (desktop computer, laptop computer, notebook personal computer, workstation, tablet computer, mobile phone, smartphone, PDA, wearable terminal, or the like) such as a manager of the inspection object 100And processing a message indicating a change in the state of the object 100. This enables a manager or the like of the inspection object 100 to know the state change of the inspection object 100, and to take an accurate measure.

the communication unit 27 has the following functions: the sensor device 10 communicates with, transmits control data to the sensor device 10, and receives vibration information on the vibration of the inspection object 100 detected by the sensor 13 of the sensor device 10 from the sensor device 10. The communication unit 27 also has a function of communicating with a user device of a manager of the inspection object 100. The administrator of the inspection object 100 can communicate with the detection processing device 20 via the communication unit 27 to change various settings of the detection processing device 20 (for example, settings such as at what intervals (every day, every week, etc.) the detection processing is to be executed). The detection processing device 20 can transmit the accumulated data and the message to the user device of the administrator of the inspection target 100 via the communication unit 27. The communication unit 27 performs communication with the sensor device 10 and the user device of the administrator of the inspection object 100 by various wired communication and wireless communication, as in the communication unit 14 described above. The communication unit 27 may communicate with various external apparatuses other than the sensor apparatus 10 and the user apparatus of the administrator of the inspection object 100 by various wired communications and wireless communications.

Further, the supply of power to each component of the detection processing device 20 may be realized by a built-in power supply such as a battery built in the detection processing device 20, or may be realized by an external power supply provided outside the detection processing device 20 and connected to the detection processing device 20 through a power supply line.

As described above, the detection system 1 of the present invention uses the VCM type vibration unit 11 to apply vibration to the inspection object 100, and the VCM type vibration unit 11 includes: a coil 112 through which an electric signal supplied from the drive circuit 12 flows; a spring 113 provided in a vibratable manner; and a magnet 114b attached to the spring 113 and disposed so as to be separated from the coil 112. Therefore, it is not necessary to form the vibration unit 11 with a material having high impact resistance as in the conventional technique using a pulse hammer. Further, since the VCM type vibration unit 11 can generate large vibration at a relatively low input voltage, it is not necessary to apply a high input voltage to the vibration unit 11 as in the conventional technique using a piezoelectric element. Therefore, according to the present invention, simplification, downsizing, and power saving of the detection system 1 can be achieved.

In the present embodiment, the sensor device 10 and the detection processing device 20 are described as separate devices housed in different housings, but the present invention is not limited to this. For example, the unit providing the function equivalent to the sensor device 10 and the unit providing the function equivalent to the detection processing device 20 may be housed in one case and implemented as one device.

< second embodiment of detection System >

next, a detection system according to a second embodiment of the present invention will be described with reference to fig. 8. Fig. 8 is a conceptual diagram illustrating a detection system according to a second embodiment of the present invention. Next, the detection system of the second embodiment will be described mainly with respect to differences from the detection system of the first embodiment, and descriptions of the same items will be omitted.

the detection system 1 of the second embodiment is the same as the detection system 1 of the first embodiment except that the detection system 1 includes a plurality of sensor devices 10, and the detection processing device 20 is connected to the plurality of sensor devices 10 so as to be able to communicate via the network 30.

The detection processing device 20 in the present embodiment may be a single device connected to the network 30, or may be implemented in a server connected to the network 30.

A plurality of sensor devices 10 of the present embodiment are mounted on one inspection object 100. The plurality of sensor devices 10 and the detection processing device 20 are connected so as to be able to communicate via the network 30.

the network 30 is a wide range of networks such as an intranet, a Local Area Network (LAN), a Wide Area Network (WAN), the internet, a combination of these networks, and the like. The network 30 may be a private network or a shared network. Shared networks are connections between various kinds of networks, communicating with each other using various protocols (e.g., HTTP, TCP/IP, WAP). The network 30 may include various network devices such as a router, a bridge, a server, an arithmetic device, and a storage device.

The detection processing device 20 receives vibration information of the vibration of the inspection object 100 from the plurality of sensing devices 10 via the network 30. Thus, the detection processing device 20 can detect not only whether there is a change in the state of each part of the inspection object 100 to which each sensor device 10 is attached, but also whether there is a change in the state of the entire inspection object 100. The detection system 1 of this type is particularly useful when the inspection object 100 is a large structure such as a bridge or a tunnel.

< third embodiment of detection System >

Next, a detection system according to a third embodiment of the present invention will be described with reference to fig. 9. Fig. 9 is a conceptual diagram illustrating a detection system according to a third embodiment of the present invention. Next, the detection system of the third embodiment will be described mainly with respect to differences from the detection system of the second embodiment, and descriptions of the same items will be omitted.

The detection system 1 according to the third embodiment is the same as the detection system 1 according to the second embodiment except that a plurality of sensor devices 10 are attached to a plurality of different inspection targets 100.

In the detection system 1 of the present embodiment, a plurality of sensor devices 10 are attached to a plurality of different inspection objects 100, respectively. This is particularly useful in the case where a plurality of relatively small inspection targets 100 are arranged in a separated manner.

< detection method >

Next, the detection method of the present invention will be described with reference to fig. 10. The detection method of the present invention can be executed using the detection system 1 of the present invention described above and any system having the same function as the detection system 1 of the present invention, and the detection method of the present invention will be described below as being executed using the detection system 1. Fig. 10 is a flow chart illustrating the detection method of the present invention.

The detection method S100 of the present invention is performed at prescribed intervals (e.g., hourly, daily, weekly, monthly, etc.). In step S101, control data is generated by the processor 21 of the detection processing device 20, and the generated control data is transmitted to the sensor device 10 via the communication unit 27. The control data generated and transmitted is used to determine which of the pulse signal, the sweep signal, and the random signal the drive circuit 12 in the sensing device 10 supplies to the vibration unit 11.

In step S102, the control data is received by the communication unit 14 of the sensor device 10 and transmitted to the drive circuit 12. The drive circuit 12 supplies any of a pulse signal, a sweep signal, and a random signal to the vibration unit 11 in accordance with the control data. Next, in step S103, the vibration unit 11 is driven by an electric signal supplied from the drive circuit 12, and the vibration unit 11 is vibrated. When the vibration unit 11 vibrates, the vibration of the vibration unit 11 is applied to the inspection object 100, so that the inspection object 100 vibrates.

Next, in step S104, the sensor 13 detects vibration of the inspection object 100. In step S105, the sensor 13 transmits vibration information about the detected vibration of the inspection object 100 to the detection processing device 20 via the communication unit 14. In step S106, the detection processing device 20 receives vibration information related to the vibration of the inspection object 100 via the communication unit 27.

In step S107, the processor 21 of the detection processing device 20 calculates the coherence γ between the vibration of the vibration unit 11 of the sensing device 10 and the vibration of the inspection object 100 using the coherence calculation section 25². Coherency gamma²Is calculated based on the vibration information on the vibration of the vibration unit 11 stored in the storage unit 24 and the received vibration information on the vibration of the inspection object 100. Further, the vibration information on the vibration of the vibration unit 11 used at this time corresponds to the vibration when the electric signal of the kind determined from the control data is supplied to the vibration unit 11. For example, when the type of the electric signal specified from the control data is a pulse signal, the vibration pair of the vibration unit 11 when the pulse signal is supplied to the vibration unit 11 among the vibration information of the vibration unit 11 stored in the storage unit 24 is used in step S107The corresponding vibration information.

The processor 21 discriminates the calculated coherence y²Whether or not it is 0.5 or more. At the moment of discrimination as calculated coherence gamma²If the frequency is less than 0.5, the processor 21 determines that the vibration (resonance) of the inspection object 100 cannot be sufficiently excited by the vibration of the vibration unit 11, and the process proceeds to step S108. In step S108, the processor 21 determines the coherency γ²Whether the number of times less than 0.5 reaches a prescribed number of times. Here, the predetermined number of times corresponds to the number of electric signals that the drive circuit 12 can supply to the vibration unit 11. For example, when the drive circuit 12 is configured to be able to supply three signals, that is, a pulse signal, a sweep signal, and a random signal, the predetermined number of times is three times.

In step S108, the coherence γ is determined²If the number of times of less than 0.5 has not reached the predetermined number of times, the process proceeds to step S109. In step S109, the processor 21 changes the control data to change the electric signal supplied from the drive circuit 12 to the vibration unit 11 to a type that has not been supplied to the vibration unit 11. For example, in the case where the pulse signal has been supplied to the vibration unit 11, the electric signal supplied from the drive circuit 12 to the vibration unit 11 is changed to a sweep signal or a random signal. After that, the process returns to S101.

On the other hand, in step S108, it is determined that the coherence γ is present²When the number of times smaller than 0.5 has reached the predetermined number of times, the process proceeds to step S110. Coherency gamma²The number of times less than 0.5 having reached the prescribed number of times means that the vibration (resonance) of the inspection object 100 cannot be sufficiently excited by the vibration generated by the vibration unit 11 in accordance with the electric signal that the drive circuit 12 can supply to the vibration unit 11. In this case, the sensing apparatus 10 is highly likely to have some problems. For example, assume that there may be a problem that the vibration unit 11 has come off the inspection object 100, that the vibration unit 11 or the sensor 13 has failed, that sufficient power is not supplied to the sensing device 10, or the like. Therefore, in step S110, the processor 21 transmits an error message indicating that an error is detected to a user device such as a manager of the inspection object 100 via the communication unit 27, and ends the process. By mixingSuch an error message is transmitted to a user device such as a manager of the inspection target 100, and the manager of the inspection target 100 can appropriately deal with the error message by checking the sensor device 10.

On the other hand, the calculated coherence γ is discriminated in step S107²If the value is 0.5 or more, the process proceeds to step S111. In step S111, the processor 21 calculates the resonance frequency f of the vibration of the inspection object 100 based on the vibration information on the vibration of the inspection object 100 using the resonance frequency calculation unit 23_r. Calculating the resonance frequency f of the vibration of the inspection object 100_rResonance frequency f as vibration of the current test object 100_rStored in the storage unit 24.

In step S112, the processor 21 uses the state change detection unit 26 to calculate the resonance frequency f of the vibration of the inspection object 100 calculated by the resonance frequency calculation unit 23_rAnd the reference resonance frequency f in the storage unit 24_refOr the resonance frequency f of the vibration of the previous test object 100 stored in the storage unit 24_rComparing them, thereby calculating the resonance frequency f calculated by the resonance frequency calculating unit 23_rAnd the reference resonance frequency f stored in the storage unit 24_refOr previous resonance frequency f_rThe difference between them.

in step S113, the resonance frequency f calculated by the resonance frequency calculation unit 23 is determined_rAnd the reference resonance frequency f stored in the storage unit 24_refOr previous resonance frequency f_rthe absolute value of the difference, i.e. the resonance frequency f_rWhether or not the amount of change in (c) is equal to or greater than a predetermined threshold value. In step S113, the absolute value (resonance frequency f) of the calculated difference is determined_rIs less than the predetermined threshold value), the process proceeds to step S114. In step S114, it is detected that there is no change in the state of the inspection object 100, and the processor 21 executes processing according to the detection result, thereby ending the processing.

On the other hand, the absolute value (resonance frequency f) of the calculated difference is determined in step S113_rThe amount of change) is equal to or greater than the predetermined threshold value, the process proceeds to step S115. In step S115, detection is performedWhen a state change of the inspection object 100 is detected, the processor 21 executes processing corresponding to the detection result, and the processing is terminated.

the detection system 1 and the detection method S100 according to the present invention have been described above based on the illustrated embodiments, but the present invention is not limited thereto. The respective configurations of the present invention can be replaced with or added to any configurations that can exhibit the same function.

For example, the number and types of components of the detection system 1 shown in fig. 1 are merely illustrative, and the present invention is not limited thereto. A mode in which any component is added or combined or a mode in which any component is deleted without departing from the principle and the intent of the present invention is also within the scope of the present invention. The components of the detection system 1 may be implemented by hardware, software, or a combination thereof.

In addition, the number of the detection processing apparatuses 20 shown in the first to third embodiments is one, but the present invention is not limited thereto. The inspection system 1 of the present invention may also include a plurality of inspection processing devices 20. The plurality of detection processing devices 20 may each communicate with the same sensor device 10 to detect a change in the state of the inspection object 100, or may each communicate with a different sensor device 10 to detect a change in the state of the inspection object 100.

The number and types of steps in the detection method S100 shown in fig. 10 are merely examples for explanation, and the present invention is not limited thereto. The present invention is also within the scope of the present invention in which any process is added or combined for any purpose or any process is deleted without departing from the principle and intent of the present invention.

Industrial applicability

The detection system and the detection method of the present invention use a VCM (Voice Coil Motor) type vibration unit as a vibrator for vibrating an inspection object, the VCM type vibration unit including: a coil through which an electric signal supplied from a driving circuit flows; a spring provided in a vibratable manner; and a magnet attached to the spring and disposed so as to be separated from the coil. Therefore, it is not necessary to form the vibration unit (vibrator) with a material having high impact resistance as in the conventional art using a pulse hammer. Further, since the VCM type vibration unit can generate large vibration at a relatively low input voltage, it is not necessary to apply a high input voltage to the vibration unit as in the conventional technique using a piezoelectric element. Therefore, according to the present invention, simplification, downsizing, and power saving of the detection system can be achieved. Therefore, the present invention has industrial applicability.