1. A low-frequency longitudinal wave detection method is characterized by comprising the following steps:

s1: arranging a circular sound-receiving plate, dividing the circular sound-receiving plate into at least two sector area units with the same specification, wherein each sector area unit is provided with a detector;

s2: a rotating shaft is arranged at the center of the circular sound-receiving plate, and a shielding plate is arranged on the shaft;

s3: one side of the circular sound-receiving plate close to the shielding plate faces the detection direction;

s4: the rotating shaft is driven by the motor to rotate to drive the shielding plate to rotate around the axis of the rotating shaft, and meanwhile, the round sound receiving plate is ensured not to rotate, so that the time T of one circle of rotation of the shielding plate is obtained;

s5: outputting detector detection signals of all sector area units once every T-interval time;

s6: judging whether the error value of the detector detection signals of any two adjacent sector area units is greater than a preset threshold value, if so, sending the detector detection signals of all the sector area units to a control center, and executing the step S7; otherwise, returning to the step S5;

s7: the control center analyzes the detection signal and decodes correct longitudinal wave information.

2. A low frequency longitudinal wave detection method according to claim 1, characterized in that: in step S1, the circular sound absorbing panel is divided into N sectors of 360 °/N degrees.

3. A low frequency longitudinal wave detection method according to claim 1, characterized in that: when step S1 is executed, the detector is an oscillation receiving device connected with a current conversion device; and the number of detectors on each sector area unit is at least one.

4. A low frequency longitudinal wave detection method according to claim 1, characterized in that: when step S2 is performed, the length of the baffle is not less than the radius of the circular sound-absorbing panel.

5. A low frequency longitudinal wave detection method according to claim 1, characterized in that: when step S3 is performed, the detector is disposed between the circular sound-absorbing plate and the shielding plate so that the shielding plate can shield the detection direction of the detector.

6. A low frequency longitudinal wave detection method according to claim 1, characterized in that: in step S4, the rotation speed of the shutter around the axis of the rotation shaft is not less than 20 turns per second, and the time value of T is not more than 0.05 second.

7. A low frequency longitudinal wave detection method according to claim 3, characterized in that: in step S5, the oscillation receiving device in the detector obtains the oscillation signal, and the current converting device converts the oscillation signal into a current signal for output.

8. The method for detecting low-frequency longitudinal waves according to claim 7, wherein: when step S5 is executed, the vibration signal received by the vibration receiver cancels the vibration generated by the rotation of the shielding plate driven by the motor.

9. A low frequency longitudinal wave detection method according to claim 1, characterized in that: before step S6 is executed, a predetermined threshold value is set.

10. A low frequency longitudinal wave detection method according to claim 9, characterized in that: in step S7, a longitudinal wave pretension is issued before decoding the longitudinal wave information.

Background

With the rapid progress of the technology, various waves are applied more and more, the wave division is various, the wave division is divided into high frequency and low frequency in frequency, the wave division is divided into transverse wave and longitudinal wave in the vibration direction, wherein light and electromagnetic wave are transverse waves, and sound wave is transverse wave and longitudinal wave.

The method has many uses for longitudinal waves, such as the detection of the interior of an object and the detection of earthquake longitudinal waves, the transmission speed of the longitudinal waves of the earthquake is higher than that of transverse waves, the early warning is sent out at the first time when the longitudinal waves are detected, casualties and economic losses can be effectively reduced, the detection of the interior structure of the object, such as the detection of the interior structure of a steel column, can effectively eliminate unqualified parts, the use safety is high, but no matter what kind of longitudinal waves are detected, the detection precision is high, particularly the low-frequency longitudinal waves sent out by the earthquake, the quick detection and quick response are needed, for example, Chinese patent invention CN112684504A discloses a method for quickly detecting urban underground cavities based on a total scattering model, a mobile detection device is firstly assembled and comprises a plurality of detection units at equal intervals, and is adopted to collect scattered wave signals once in a target detection area, the system moves once, so that the multiple scattered wave collection is completed rapidly and efficiently; then, an urban underground total scattering model is established for the acquired signal data to perform multiple covering imaging of scattered waves, the scattered wave signals in the multiple acquisition process within the aperture Dx range are superposed and calculated, and imaging is performed by adopting corresponding offset speeds during different arrangement acquisition, so that the extraction capability and detection accuracy of the scattered waves are improved; and finally, comprehensively analyzing the abnormal position and size by a known method according to the total scattering velocity profile and the imaging profile, and realizing the rapid and accurate detection of the urban underground cavity.

However, the above detection method still has the following disadvantages: the structure is complicated, and manufacturing cost is high, uses the trouble, needs a large amount of manual operation and removal during the measurement, and measurement efficiency is underneath, and application scope is little, can't carry out industry volume production, and does not utilize the self characteristic of longitudinal wave to carry out to the monitoring, and detection accuracy is low.

Therefore, in order to solve the above problems, it is necessary to design a reasonable low-frequency longitudinal wave detection method.

Disclosure of Invention

The invention aims to provide a low-frequency longitudinal wave detection method which is simple in structure, convenient to use, capable of effectively utilizing the characteristics of low-frequency longitudinal waves to carry out targeted detection, high in detection accuracy, capable of effectively carrying out rapid detection on earthquake longitudinal waves or other longitudinal waves and capable of carrying out mass production and use.

In order to achieve the purpose, the invention is realized by adopting the following technical scheme:

a low-frequency longitudinal wave detection method comprises the following steps:

s1: arranging a circular sound-receiving plate, dividing the circular sound-receiving plate into at least two sector area units with the same specification, wherein each sector area unit is provided with a detector;

s2: a rotating shaft is arranged at the center of the circular sound-receiving plate, and a shielding plate is arranged on the shaft;

s3: one side of the circular sound-receiving plate close to the shielding plate faces the detection direction;

s4: the rotating shaft is driven by the motor to rotate to drive the shielding plate to rotate around the axis of the rotating shaft, and meanwhile, the round sound receiving plate is ensured not to rotate, so that the time T of one circle of rotation of the shielding plate is obtained;

s5: outputting detector detection signals of all sector area units once every T-interval time;

s6: judging whether the error value of the detector detection signals of any two adjacent sector area units is greater than a preset threshold value, if so, sending the detector detection signals of all the sector area units to a control center, and executing the step S7; otherwise, returning to the step S5;

s7: the control center analyzes the detection signal and decodes correct longitudinal wave information.

In the present invention, it is preferable that the circular sound-absorbing panel is divided into N sectors of 360 °/N angle in step S1.

Preferably, in step S1, the detector is an oscillation receiving device connected to a current conversion device; and the number of detectors on each sector area unit is at least one.

Preferably, in the step S2, the length of the baffle is not less than the radius of the circular sound absorbing plate.

As a preferable aspect of the present invention, when step S3 is performed, the probe is disposed between the circular sound-absorbing plate and the shielding plate so that the shielding plate can shield the detection direction of the probe.

Preferably, in step S4, the rotation speed of the shutter around the axis of the rotation shaft is not less than 20 turns per second, and the time value of T is not more than 0.05 second.

Preferably, in step S5, the oscillation receiving device in the detector acquires the oscillation signal, and the current converting device converts the oscillation signal into the current signal for output.

Preferably, in step S5, the vibration signal received by the vibration receiver cancels the vibration generated by the rotation of the shielding plate driven by the motor.

As a preferable aspect of the present invention, the predetermined threshold is set before step S6 is executed.

In a preferred embodiment of the present invention, the longitudinal wave pretension is generated before decoding the longitudinal wave information in step S7.

The low-frequency longitudinal wave detection method has the beneficial effects that: simple structure, convenient to use effectively utilizes the characteristic of low frequency longitudinal wave to carry out the pertinence and surveys, surveys the accuracy height, can effectively carry out earthquake longitudinal wave or other longitudinal waves's quick detection, can produce in a large number and use.

Drawings

FIG. 1 is a schematic flow chart of a low-frequency longitudinal wave detection method according to the present invention.

Detailed Description

The following are specific examples of the present invention and further describe the technical solutions of the present invention, but the present invention is not limited to these examples.

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the modules and structures set forth in these embodiments does not limit the scope of the invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques, methods, and systems known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.

Example (b): as shown in fig. 1, which is only one embodiment of the present invention, a low-frequency longitudinal wave detection method includes the following steps:

s1: arranging a circular sound-receiving plate, dividing the circular sound-receiving plate into at least two sector area units with the same specification, wherein each sector area unit is provided with a detector;

in step S1, the circular sound absorbing panel is divided into N sectors of 360 °/N degrees, and generally, the circular sound absorbing panel is divided into 3 sectors of 120 degrees or 4 sectors of 90 degrees.

When step S1 is executed, the detector is an oscillation receiving device connected with a current conversion device; and the number of detectors on each sector area unit is at least one. A plurality of detectors are densely paved on each sector unit, and preferably, the number of the detectors on each sector unit is the same and the arrangement mode of the detectors is the same.

S2: a rotating shaft is arranged at the center of the circular sound-receiving plate, and a shielding plate is arranged on the shaft;

the extending direction of the rotating shaft is perpendicular to the plane of the circular sound-receiving plate, the shielding plate is parallel to the plane of the circular sound-receiving plate, and the end of the shielding plate is connected to the rotating shaft in the middle of the circular sound-receiving plate and rotates around the axis of the rotating shaft.

When step S2 is performed, the length of the baffle is not less than the radius of the circular sound-absorbing panel. That is, the shielding plate rotates one turn, and all the detectors are shielded by the shielding plate at least at a certain moment.

S3: one side of the circular sound-receiving plate close to the shielding plate faces the detection direction;

here, when step S3 is performed, the probe is disposed between the circular sound-receiving panel and the shielding panel disposed in front of the probe on the circular sound-receiving panel so that the shielding panel can shield the detection direction of the probe.

Of course, the width of the shielding plate is not less than the width of the detector, i.e. the detector can be completely shielded when the shielding plate is directly in front of the detector.

S4: the rotating shaft is driven by the motor to rotate to drive the shielding plate to rotate around the axis of the rotating shaft, and meanwhile, the round sound receiving plate is ensured not to rotate, so that the time T of one circle of rotation of the shielding plate is obtained;

here, the circular sound absorbing plate is fixed, the motor is arranged behind the circular sound absorbing plate, the motor drives the rotating shaft to rotate, and the shielding plate rotates along with the rotating shaft.

In step S4, the rotation speed of the shutter around the axis of the rotation shaft is not less than 20 turns per second, and the time value of T is not more than 0.05 second. That is, it is necessary to make the rotation speed of the shutter sufficiently fast.

According to the specification of the motor and the number of teeth of the transmission gear, the time T for driving the shielding plate to rotate for a circle by the motor can be obtained when the motor is installed.

S5: outputting detector detection signals of all sector area units once every T-interval time;

that is, when detecting the target object, the detector detection signals of all sector area units are output once every time the shielding plate rotates one circle.

It should be noted that the detection of the detector signal is only started when the shutter is rotationally stabilized.

In step S5, the oscillation receiving device in the detector obtains the oscillation signal, and the current converting device converts the oscillation signal into a current signal for output.

In addition, when step S5 is executed, the vibration signal received by the vibration receiver cancels the vibration generated by the rotation of the shielding plate driven by the motor.

S6: judging whether the error value of the detector detection signals of any two adjacent sector area units is greater than a preset threshold value, if so, sending the detector detection signals of all the sector area units to a control center, and executing the step S7; otherwise, returning to the step S5;

before step S6 is executed, a predetermined threshold value is set.

That is to say, according to the self characteristics of low-frequency longitudinal waves, the transmission speed of sound velocity is constant when the sound velocity is transmitted in the same uniform medium, but the transmission speed is changed in different media, the longitudinal waves have good object penetrability, and then the longitudinal waves can penetrate through the shielding plate to reach the detector, and the wave spacing of the low-frequency longitudinal waves is larger than that of the high-frequency longitudinal waves; when the method is used for detecting the low-frequency longitudinal wave, because the shielding plate rotates at a high speed, it can be understood that in the time T, the shielding plate rotates for a circle around the rotating shaft to shield all detectors once, and by utilizing the two points that the fluctuation direction of the longitudinal wave is parallel to the wave transmission direction and the wave distance of the low-frequency longitudinal wave is larger, at least one longitudinal wave passes through the shielding plate and arrives at the detector, the intensities of the longitudinal wave which does not pass through the shielding plate and the longitudinal wave which passes through the shielding plate are different, the error value of the detector detection signals of any two adjacent sector area units is larger than a preset threshold value, the circular sound receiving plate receives the low-frequency longitudinal wave, and the detector detection signals of all the sector area units are sent to the control center for further analysis.

S7: the control center analyzes the detection signal and decodes correct longitudinal wave information.

In step S7, a longitudinal wave pretension is issued before decoding the longitudinal wave information. Namely, if the method is used for earthquake prediction, an earthquake early warning is given out preferentially before the content of the longitudinal wave is analyzed so as to reduce earthquake loss.

The low-frequency longitudinal wave detection method is simple in structure, convenient to use, capable of effectively utilizing the characteristics of low-frequency longitudinal waves to carry out targeted detection, high in detection accuracy, capable of effectively carrying out rapid detection on seismic longitudinal waves or other longitudinal waves, and capable of being produced and used in large quantities.

The present invention is not limited to the above-described specific embodiments, and various modifications and variations are possible. Any modifications, equivalents, improvements and the like made to the above embodiments in accordance with the technical spirit of the present invention should be included in the scope of the present invention.