CN211904056U

CN211904056U - Pit depth measuring structure

Info

Publication number: CN211904056U
Application number: CN202020817541.4U
Authority: CN
Inventors: 时啸宇; 韩佳一; 陆映同; 张健
Original assignee: Nanjing Institute of Technology
Current assignee: Nanjing Institute of Technology
Priority date: 2020-05-17
Filing date: 2020-05-17
Publication date: 2020-11-10
Anticipated expiration: 2030-05-17

Abstract

A pit depth measuring structure comprises a pit, a connecting side rod, a bridging rod, a linear array CCD (charge coupled device), a rotating mechanism, a laser, an FPGA (field programmable gate array) module, a data acquisition control module and a computer; the utility model discloses a mirror reflection who utilizes light constructs isosceles triangle and realizes hole degree of depth measuring device, beat a branch of laser on the horizontal plane of hole bottom through the laser instrument, when mirror reflection's laser reachd the linear array CCD with the same horizontal plane at laser instrument transmission point place, received by linear array CCD, an isosceles triangle is constituteed to the transmission point of so laser instrument, the reflection point of the surface of water, linear array CCD laser receiving point three-point line, as long as at last solve isosceles triangle's height can obtain the hole degree of depth, the utility model discloses it is convenient, fast to measure.

Description

Pit depth measuring structure

Technical Field

The utility model relates to a hole depth measurement structure.

Background

In the building construction, some ponding pits can be frequently encountered, most of the pits are deep and complex, and direct measuring tools such as calipers are difficult to apply. Indirect measurements are gaining importance in many scenarios. For a vertical pit, the vertical section of the vertical pit is rectangular on a two-dimensional plane, so that the depth measurement of the pit can be converted into rectangular length measurement, the traditional measuring tool, such as a tape measure, cannot be perpendicular to the measuring surface at the bottom of the pit in actual measurement, and on the other hand, due to insufficient light in the pit, the bending of the tape measure in the pit, the stable arrangement of the top end of the tape measure on the measuring surface and other measuring factors cannot be guaranteed, and the measuring result has larger errors.

Disclosure of Invention

To the weak point of above-mentioned prior art, the utility model provides a problem do: the pit depth measuring structure is convenient to measure and small in error.

In order to solve the above problem, the utility model discloses the technical scheme who takes as follows:

a pit depth measuring structure comprises a pit, a connecting side rod, a bridging rod, a linear array CCD (charge coupled device), a rotating mechanism, a laser, an FPGA (field programmable gate array) module, a data acquisition control module and a computer; water is injected into the pit; two connecting side rods are arranged, and one connecting side rod is respectively arranged on two sides of the upper end of the pit; the connecting side rods on the two sides of the upper end of the pit are distributed in parallel; the bridging rod is arranged between the two connecting side rods, and two ends of the bridging rod are respectively arranged on the connecting side rods; the linear array CCD is arranged on the lower side of one end of the bridging rod; the rotating mechanism and the laser are arranged on the lower side of the other end of the bridging rod; the rotating mechanism drives the laser to rotate; the rotating mechanism is connected with the FPGA module; the linear array CCD is connected with the data acquisition control module; the data acquisition control module is connected with a computer; the FPGA module is connected to a computer through the data acquisition control module.

Furthermore, both ends of the bridging rod are respectively arranged in the middle of the connecting side rod.

Further, the rotating mechanism drives the laser to project and rotate from the vertical downward direction to the direction of one side of the linear array CCD for projection.

Furthermore, the emitting point of the laser and the receiving point of the linear array CCD are positioned on the same horizontal plane.

Furthermore, the emitted light of the laser, the reflected light passing through the water surface in the pit hole and the receiving point of the linear array CCD are positioned on the same vertical plane.

Further, the rotating mechanism is a stepping motor.

The beneficial effects of the utility model

The utility model discloses a mirror reflection who utilizes light constructs isosceles triangle and realizes hole degree of depth measuring device, beat a branch of laser on the horizontal plane of hole bottom through the laser instrument, when mirror reflection's laser reachd the linear array CCD with the same horizontal plane at laser instrument transmission point place, received by linear array CCD, an isosceles triangle is constituteed to the transmission point of so laser instrument, the reflection point of the surface of water, linear array CCD laser receiving point three-point line, as long as at last solve isosceles triangle's height can obtain the hole degree of depth, the utility model discloses it is convenient, fast to measure.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is the triangular path structure formed by the emitting point of the laser, the reflecting point of the water surface and the linear array CCD laser receiving point.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

As shown in fig. 1 and 2, a pit depth measuring structure comprises a pit 1, a connecting side rod 2, a bridging rod 3, a linear array CCD4, a rotating mechanism 5, a laser 6, an FPGA module 9, a data acquisition control module 7 and a computer 8; water is injected into the pit 1; two connecting side rods 2 are arranged, and one connecting side rod 2 is respectively arranged on two sides of the upper end of the pit 1; the connecting side rods 2 on the two sides of the upper end of the pit 1 are distributed in parallel; the bridging rod 3 is arranged between the two connecting side rods 2, and two ends of the bridging rod 3 are respectively arranged on the connecting side rods 2; the linear array CCD4 is arranged at the lower side of one end of the bridging rod 3; the rotating mechanism 5 and the laser 6 are arranged at the lower side of the other end of the bridging rod 3; the rotating mechanism 5 drives the laser 6 to rotate; the rotating mechanism 5 is connected with the FPGA module 9; the linear array CCD4 is connected with the data acquisition control module 7; the data acquisition control module 7 is connected with a computer 8; the FPGA module 9 is connected to the computer 8 through the data acquisition control module 7. More preferably, both ends of the bridging rod 3 are respectively attached to intermediate positions of the connecting side rods 2. Further, the rotating mechanism 5 drives the laser 6 to perform projection rotation from a vertical downward direction to a direction toward one side of the line CCD 4. Further preferably, the emitting point of the laser 6 and the receiving point of the line CCD4 are on the same horizontal plane. Further, the emitted light of the laser 6 and the reflected light after passing through the water surface in the pit hole 1 are on the same vertical plane with the receiving point of the linear array CCD 4. More preferably, the rotating mechanism 5 is a stepping motor. The utility model discloses a mirror reflection of light constructs isosceles triangle and realizes pothole depth measuring device, beat a branch of laser on the horizontal plane of pothole 1 bottom through laser instrument 6, mirror reflection's laser reachs when the linear array CCD4 with the same horizontal plane of laser instrument transmission point place, is received by linear array CCD4, so the transmission point B of laser instrument, the reflection point C of the surface of water, an isosceles triangle DELTA BAC is constituteed to linear array CCD laser reception point A three-point line, as long as the high h of solving isosceles triangle DELTA BAC can obtain the pothole depth at last, the utility model discloses it is convenient to measure, speed is swift.

The utility model discloses an operation flow as follows:

1. and (3) starting a power supply device to supply power to each part, starting a computer terminal to drive the FPGA module 9 to control the stepping motor 5 to rotate at a constant speed when the laser works, so that the laser 6 which is originally vertically irradiated downwards rotates towards one end of the linear array CCD4 under the drive of the stepping motor 5.

2. The laser generates mirror reflection on the water surface at the bottom of the pit, and the reflected laser is finally received by the linear array CCD4 along with the rotation of the stepping motor 5.

3. The light intensity information received by the linear array CCD4 is processed by the data acquisition control module 7 and then transmitted to the computer 8 through the serial port, a digital video signal is obtained in the computer, and the image processing is carried out in the computer to obtain the position of laser emission.

4. Analyzing the discrete signal, finding out the pixel point corresponding to the highest intensity value in the signal, calculating the distance AB between the laser receiving point A and the laser emitting point B as the base side length of the isosceles triangle, and calculating the residual angle alpha of the angle rotated by the stepping motor at the moment₁And the base angle is taken as the base angle of the isosceles triangle.

After the above steps are completed, the data are analyzed by the computer, and the base length AB and the base angle alpha of the isosceles triangle are known₁In the case of (3), the height h of the isosceles triangle is determined, and the height is the depth of the pit.

The specific measurement and calculation process is as follows:

a laser section: the laser emits light stably after being electrified, the FPGA generates n periods of square wave signals in one acquisition period of the linear array CCD, and when each rising edge arrives, the stepping motor rotates by m degrees, and the emergent laser also moves along with the square wave signals until the emergent laser is detected by the linear array CCD.

Linear array CCD part: when laser irradiates the linear array CCD, the linear array CCD receives the optical signal and outputs a digital video signal, the coordinates of the light spot on the linear array CCD are calculated after image processing, and the horizontal distance x from the point A to the laser emergent point B is calculated. And recording the rising edge of the FPGA working in the kth period at the moment.

The depth calculating section: firstly, the angle (k x m) of the stepping motor rotating after k periods is calculated, and the rest angle is taken as alpha₁Then, then

The angle is the base angle of an isosceles triangle formed by the laser incident point B, the reflection point C and the laser receiving point A.

The obtained depth of the pit is the height h of the bottom edge of delta ABC shown in FIG. 2;

in delta BCD, the tangent value of angle B is

∠BIs just the angle alpha₁；

Is obtained by formula (1) and formula (2)

Further simplifying the formula (3)

Thus, the above height h is obtained.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A pit depth measuring structure is characterized by comprising a pit, a connecting side rod, a bridging rod, a linear array CCD (charge coupled device), a rotating mechanism, a laser, an FPGA (field programmable gate array) module, a data acquisition control module and a computer; water is injected into the pit; two connecting side rods are arranged, and one connecting side rod is respectively arranged on two sides of the upper end of the pit; the connecting side rods on the two sides of the upper end of the pit are distributed in parallel; the bridging rod is arranged between the two connecting side rods, and two ends of the bridging rod are respectively arranged on the connecting side rods; the linear array CCD is arranged on the lower side of one end of the bridging rod; the rotating mechanism and the laser are arranged on the lower side of the other end of the bridging rod; the rotating mechanism drives the laser to rotate; the rotating mechanism is connected with the FPGA module; the linear array CCD is connected with the data acquisition control module; the data acquisition control module is connected with a computer; the FPGA module is connected to a computer through the data acquisition control module.

2. A pothole depth measuring structure according to claim 1, wherein both ends of the bridging rod are mounted to middle positions of the side connecting rods, respectively.

3. A pothole depth measurement structure according to claim 1, wherein the rotation mechanism drives the laser to rotate from a vertical downward direction to a direction to one side of the linear array CCD.

4. A pothole depth measurement structure according to claim 1, wherein an emitting point of the laser and a receiving point of the line CCD are on a same horizontal plane.

5. A pit depth measuring structure according to claim 1, wherein the emitted light from the laser and the reflected light from the water surface in the pit are on the same vertical plane as the receiving point of the linear array CCD.

6. A pothole depth measurement structure according to claim 1, wherein the rotation mechanism is a stepper motor.