Pavement skid resistance detection method based on laser sensor

Abstract

The invention discloses a road surface anti-skid performance detection method based on a laser sensor, relates to the technical field of road surface flatness detection, and solves the problem that the confirmed flatness data error is relatively large due to the confirmation error of the same characteristic light velocity. A multi-wavelength detection laser beam is generated through preset parameters, and the wavelength of a received light beam is accurately judged in combination with a unique waveform analysis strategy; a waveform segment is locked by using a zero value point, and normal and interference wave bands are distinguished through coincidence verification, so that the influence of interference waves on wavelength confirmation is effectively eliminated, light beams with the same characteristics can be quickly locked through amplitude interval comparison and coincidence degree verification in a complex interference environment, the accuracy and reliability of wavelength confirmation are greatly improved, and the method is suitable for large-scale popularization and application. And misjudgment caused by interference is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of road surface flatness inspection, and specifically to a method for detecting the anti-skid performance of a road surface based on a laser sensor. Background Art

[0002] With the rapid development of the transportation industry, the anti-skid performance of the road surface has become a key factor affecting road traffic safety; traditional methods for detecting the anti-skid performance of the road surface, such as the pendulum method and the lateral force coefficient test method, etc., are mostly contact detection methods, which have problems such as low detection efficiency, large interference with traffic, and easy wear of equipment, and it is difficult to meet the requirements of modern traffic for rapid detection of the road surface.

[0003] Patent application (CN113487663B) discloses a method for calculating the texture depth of a road surface based on laser three-dimensional data, which mainly includes the following contents: 1. A line laser three-dimensional scanning device scans the road surface by moving to obtain three-dimensional data of the road surface scanning area; 2. Divide the depth matrix into small areas of a certain size, extract the maximum value and position of the partition, and use the griddata function for interpolation according to these maximum value points to obtain the MTD calculation reference matrix RS; 3. Use the griddata function for interpolation according to the three-dimensional data to obtain a new depth matrix Z'; 4. The average value of the difference matrix between RS and Z' is the MTD value of the road surface in the scanning area. The texture depth calculation method proposed by this invention makes full use of the complete three-dimensional data of the road surface, effectively avoids external noise interference, has accurate calculation, high operation efficiency, and three-dimensional intuitive display, provides effective data for the intelligent evaluation of the anti-skid performance of the road surface, and realizes three-dimensional intelligent detection and evaluation of the road surface.

[0004] Based on the detection situation of the corresponding laser sensor for the ground, the detection data associated with the corresponding laser sensor is confirmed. However, in the actual processing process, its laser is easily interfered by other light waves, resulting in a large difference between the actual returned received light beam and the emitted light beam. There is no setting for quickly confirming the same characteristics of the received light beam and the emitted light beam, resulting in an easy error in the confirmation of the same characteristic light speed in the actual confirmation process, resulting in a large error in the confirmed flatness data and unable to achieve a more accurate processing effect. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides a method for detecting the anti-skid performance of a road surface based on a laser sensor, which solves the problem that the error in the confirmation of the same characteristic light speed easily leads to a large error in the confirmed flatness data.

[0006] To achieve the above objectives, the present invention is realized through the following technical solutions: A method for detecting the anti-skid performance of a road surface based on a laser sensor, including the following steps:

[0007] Generate a detection laser beam based on preset parameters, and confirm the wavelength of the received beam based on the received beam associated with the corresponding moment, and lock the same characteristic beam. The specific method is as follows:

[0008] Based on the received beam received by the laser sensor, confirm the beam waveform associated with the corresponding received beam, and lock the zero point in the beam waveform. The zero point is the point where the waveform point amplitude is 0;

[0009] Based on the zero points calibrated in sequence from front to back, randomly record the waveforms associated with three consecutive zero points as the selected waveform segments, and determine whether this selected waveform segment completely coincides with the selected waveform segments associated before and after;

[0010] If so, record the two completely coincident selected waveform segments as the bands to be verified. By confirming the band characteristics associated with the two bands to be verified, calibrate the same characteristic beam: confirm the peak points associated with the two bands to be verified, then confirm the time interval between the two peak points, and then confirm the wave speed associated with the corresponding beam waveform. Use: wavelength = wave speed × time interval to confirm the wavelength of this beam waveform, and then compare this wavelength with the preset parameters to confirm the detection beam with the same wavelength value, and calibrate the confirmed detection beam and this received beam as the same characteristic beam;

[0011] If not, perform waveform verification on the beam waveform of this received beam, lock the interference band, and then compare the other bands that do not belong to the interference band with the waveform of the detection beam to confirm the comparison coincidence degree, and based on the confirmation result, lock the detection beam associated with this received beam and perform calibration of the same characteristic beam:

[0012] Calibrate the zero points of the beam waveform of the received beam. Starting from the first zero point, sequentially record the bands associated with three consecutive zero points as the waves to be compared from the front. Perform coincidence verification on two adjacent waves to be compared, record the non - coincident bands as the interference band, record the coincident bands as the other bands, and sequentially confirm the other bands existing in each wave to be compared. From the confirmed several other bands, select the group of other bands with the longest band length as the band to be verified;

[0013] Confirm the maximum amplitude and the minimum amplitude of the internal points in the band to be verified, record them as the amplitude range, and confirm the amplitude segments associated with this amplitude range from different detection beams. Denote the amplitude segments with the same amplitude trend as the band to be verified as the same-trend amplitude segments, and randomly select a group from the multiple groups of same-trend amplitude segments associated with a single group of detection beams for coincidence degree verification: confirm the overlapping segments of its same-trend amplitude segments and the band to be verified, and confirm the overlapping ratio based on the line length of the overlapping segments. The overlapping ratio = the line length of the overlapping segments ÷ the total line length of the band to be verified, and denote the detection beam that satisfies the overlapping ratio ≥ 95% as the pending beam. If there are multiple groups of pending beams, select the pending beam with the largest overlapping ratio value as the same-feature beam of this receiving beam. If there is only one group of pending beams, directly use it as the same-feature beam of this receiving beam;

[0014] If there is no detection beam with an overlapping ratio ≥ 95%, generate an error signal;

[0015] According to the same-feature beam determined at the corresponding moment, confirm the angular features of its detection beam and receiving beam, and perform feature processing to lock the reflection point associated with the same-feature beam, and record the height data associated with the reflection point. The specific method is as follows:

[0016] Based on the confirmed same-feature beam, determine the emission point of its detection beam and the receiving point of the receiving beam;

[0017] Then confirm the emission angle associated with its detection beam and the receiving angle of the receiving beam, and generate the emission line of its detection beam and the receiving line of the receiving beam based on the associated emission point and receiving point;

[0018] Determine the intersection point of its emission line and receiving line, denote the intersection point as the reflection point associated with the same-feature beam, and confirm the distance between this reflection point and the plane where the laser sensor is located. Denote the confirmed distance as the height data associated with this reflection point;

[0019] Based on the real-time processing process of the specified area, sequentially confirm the reflection points associated with several same-feature beams, synchronously lock the height data associated with different reflection points, perform feature confirmation on the height data of several reflection points, lock the flatness feature value of the specified area and display it. The specific method is as follows:

[0020] Based on the confirmed same-feature beam, determine the emission point of its detection beam and the receiving point of the receiving beam;

[0021] Then confirm the emission angle associated with its detection beam and the receiving angle of the receiving beam, and generate the emission line of its detection beam and the receiving line of the receiving beam based on the associated emission point and receiving point;

[0022] Determine the point where its emission line and reception line intersect, denote the intersecting point as the reflection point associated with the same characteristic light beam, and confirm the distance between this reflection point and the plane where the laser sensor is located, and denote the confirmed distance as the height data associated with this reflection point.

[0023] Preferably, the detection laser beam includes several groups of lasers with different wavelengths, and their different wavelengths are all preset parameters.

[0024] The present invention provides a method for detecting the anti-skid performance of a road surface based on a laser sensor. Compared with the prior art, it has the following beneficial effects:

[0025] In the wavelength confirmation step of the present invention, a multi-wavelength detection laser beam is generated through preset parameters, and combined with a unique waveform analysis strategy, the accurate determination of the wavelength of the received light beam is realized; the zero-value point is used to lock the waveform segment, and the normal and interference wavebands are distinguished through coincidence verification, which not only effectively eliminates the influence of interference waves on wavelength confirmation, but also can quickly lock the same characteristic light beam through amplitude interval comparison and coincidence degree verification in a complex interference environment, greatly improving the accuracy and reliability of wavelength confirmation and reducing misjudgment caused by interference.

[0026] Based on the emission angle and reception angle of the same characteristic light beam, combined with the emission point and reception point information, accurately determine the position of the reflection point and record the height data; this method constructs a calculation model based on geometric principles, and compared with the traditional method, greatly improves the accuracy of reflection point positioning and provides a reliable data basis for subsequent flatness analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic flow chart of the method of the present invention;

[0028] Figure 2 is a schematic diagram for determining the reflection point of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work shall fall within the protection scope of the present invention.

[0030] Please refer to Figure 1 , this application provides a method for detecting the anti-skid performance of a road surface based on a laser sensor, including the following steps:

[0031] Step 1: Generate a probing laser beam based on preset parameters. The probing laser beam includes several groups of lasers with different wavelengths, and all different wavelengths are preset parameters, which are determined in advance by the operator according to experience for subsequent beam confirmation. Based on the received beam associated with the corresponding moment, confirm the wavelength of the received beam and lock the laser beam with the same characteristics. Specifically, the so-called laser beam with the same characteristics refers to the probing laser and the received laser associated with the same moment. The laser with the same wavelength for both is the corresponding laser beam with the same characteristics. During the calibration process, generally, the wavelength can be directly calibrated to lock the wavelength of the corresponding received beam. Another method is to perform filtering processing. For the specific waveform with interference waves, eliminate the associated interference waves to determine its corresponding wavelength;

[0032] Among them, the specific method for confirming the wavelengths of different received beams is as follows:

[0033] Based on the received beam received by the laser sensor, confirm the beam waveform associated with the corresponding received beam, and lock the zero-value point from the beam waveform. The zero-value point is the point where the waveform point amplitude is 0;

[0034] Based on the zero-value points calibrated sequentially from front to back, randomly record the waveforms associated with three consecutive zero-value points as the selected waveform segments, and determine whether this selected waveform segment completely coincides with the selected waveform segments associated before and after (the selected waveform segments associated before and after are also the wavebands associated with three consecutive zero-value points correspondingly. That is to say, during this confirmation process, there are nine zero-value points. When checking with the wavebands before and after, if there is a situation where one group coincides, it represents a complete coincidence situation). The random process here includes several groups of selection processes, rather than saying that the selection ends after one selection. Instead, it ends when a coincident waveform segment is determined. If it cannot be determined all the time, it means there is no such situation (the specific handling measures for the non-existent situation are described in the second small paragraph later):

[0035] If there is a coincidence, record the two completely coincident selected waveform segments as the wavebands to be calibrated. Confirm the peak points associated with the two wavebands to be calibrated, then confirm the time interval between the two peak points, and then confirm the wave velocity associated with the corresponding beam waveform (this value can be directly obtained from the laser sensor). Use: wavelength = wave velocity × time interval to confirm the wavelength of this beam waveform, and then compare this wavelength with the preset parameters to confirm the probing beam with the same wavelength value. Mark the confirmed probing beam and this received beam as the laser beam with the same characteristics. If no beam with the same wavelength can be found, directly report an error, indicating that the interference degree is too severe or there are related problems with the corresponding laser sensor. Under normal circumstances, such problems will not occur;

[0036] If not, perform waveform verification on the beam waveform of this received beam, lock the interference band, then compare the waveforms of other bands that do not belong to the interference band with the waveform of the detection beam, confirm the comparison coincidence degree, and based on the confirmation result, lock the detection beam associated with this received beam and perform calibration of the same characteristic beam. Specifically, if the beam waveform of the corresponding wavelength cannot be confirmed, it belongs to the interference state, resulting in the inability to confirm the specific waveform segment of its coincidence waveform. In order to more accurately find the associated detection beam for the associated beam waveform, waveform comparison is performed to achieve the specific confirmation of the corresponding same characteristic beam;

[0037] Among them, the detailed processing method for waveform verification is as follows:

[0038] Calibrate the zero-value points of the beam waveform of the received beam. Starting from the first zero-value point, successively record the bands associated with three consecutive groups of zero-value points as the waves to be compared (there is a corresponding waveform segment between three zero-value points, and the corresponding waveform segment is a wave to be compared. For example: the zero-value points are 1, 2, 3,..., n, and the three zero-value points 1, 2, and 3 are associated with a group of waves to be compared, and the three zero-value points 4, 5, and 6 are also associated with a group of waves to be compared, and so on. Subsequently, every three consecutive zero-value points are associated with a group of waves to be compared). Perform coincidence verification on two adjacent waves to be compared, record the non-coincident bands as the interference band, record the coincident bands as other bands, and successively confirm each other band existing in each wave to be compared. From the confirmed several other bands, select the group of other bands with the longest band length as the band to be verified (each different other band is associated with a different length, so there is a group of the longest bands, which is the corresponding band to be verified. If there are several longest bands, any one can be randomly selected);

[0039] Confirm the maximum amplitude and minimum amplitude of the internal points in the band to be verified, record them as the amplitude range, and confirm the amplitude segment associated with this amplitude range from different detection beams. Denote the amplitude segment with the same amplitude trend as the band to be verified as the same-trend amplitude segment, and randomly select a group from the multiple groups of same-trend amplitude segments associated with a single group of detection beams for coincidence degree verification: confirm the coincidence segment between its same-trend amplitude segment and the band to be verified, and confirm the coincidence ratio based on the line length of the coincidence segment. The coincidence ratio = line length of the coincidence segment ÷ total line length of the band to be verified, and denote the detection beam that satisfies the coincidence ratio ≥ 95% as the pending beam. If there are multiple groups of pending beams, select the pending beam with the largest coincidence ratio value as the same-feature beam of this receiving beam. If there is only one group of pending beams, directly use it as the same-feature beam of this receiving beam. Specifically, within the corresponding receiving beam, not all bands are interfered, but there are some bands without interference. Therefore, perform front-back coincidence verification on the corresponding bands to identify the coincident bands, lock the non-interfered bands, and then select the band with the longest length value from the identified multiple non-interfered bands as the most characteristic one for comprehensive confirmation;

[0040] Perform coincidence verification on the characteristic bands from the several detection beams emitted. Since the wavelengths associated with each band are different, their trend characteristics are also different. Through the corresponding coincidence verification process, the detection beam associated with the corresponding receiving beam can be quickly locked, so as to quickly lock the same-feature beam and facilitate the subsequent specific verification of the flatness of the plane;

[0041] If there is no detection beam with a coincidence ratio ≥ 95%, generate an error signal, indicating that the corresponding receiving beam is severely interfered and the original detection beam cannot be found, and manual intervention is required.

[0042] Step 2: According to the same-feature beam determined at the corresponding moment, confirm the angular characteristics of its detection beam and receiving beam, perform feature processing, lock the reflection point associated with the same-feature beam, and record the height data associated with the reflection point. Specifically, when the detection beam is emitted, there is an emission angle, and when the corresponding receiving beam receives, there is a receiving angle. Based on the corresponding emission angle and receiving angle, the reflection point associated with the corresponding beam can be confirmed, which is convenient for the subsequent specific confirmation of the flatness;

[0043] Among them, the specific method for locking the reflection point is:

[0044] Based on the confirmed same-feature beam, determine the emission point of its detection beam and the receiving point of its receiving beam;

[0045] Reconfirm the emission angle associated with its detection beam and the reception angle of the reception beam, and generate the emission line of its detection beam and the reception line of the reception beam based on the associated emission point and reception point;

[0046] Determine the point where its emission line and reception line intersect, record the intersecting point as the reflection point associated with the same characteristic beam, and confirm the distance between this reflection point and the plane where the laser sensor is located, and record the confirmed distance as the height data associated with this reflection point;

[0047] Specifically, in combination with Figure 2 , according to the confirmed plane where the laser sensor is located, confirm the corresponding associated emission point and reception point, and simultaneously confirm the corresponding emission angle and reception angle, the corresponding emission line and reception line can be locked. There is a two-dimensional intersection point between the emission line and the reception line, and the two-dimensional intersection point is the corresponding reflection point. Based on the position of the plane, the distance associated with the corresponding reflection point can be effectively confirmed, thereby locking the corresponding height data.

[0048] Step 3: Based on the real-time processing process of the specified area, sequentially confirm the reflection points associated with several same characteristic beams, simultaneously lock the height data associated with different reflection points, perform feature confirmation on the height data of several reflection points, lock the flatness characteristic value of the specified area and display it. The specific method for feature confirmation is as follows:

[0049] Based on the different height data associated with different reflection points within the specified area, perform variance processing on several groups of height data to lock the characteristic variance;

[0050] Take the determined characteristic variance as the flatness characteristic value of this area and display it for external personnel to view. When the value of the corresponding flatness characteristic value is larger, the corresponding specified area is more uneven. When the value of the corresponding characteristic variance is smaller, it means the corresponding area is flatter. The operator can evaluate the flatness state of the corresponding area based on the specific characteristic value.

[0051] Some of the data in the above formula are numerically calculated after removing their dimensions. At the same time, the content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0052] The above embodiments are only used to illustrate the technical method of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical method of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A method for detecting the skid resistance performance of a road surface based on a laser sensor, characterized in that, It includes the following steps: Generate a detection laser beam based on preset parameters, and confirm the wavelength of the received beam based on the received beam associated with the corresponding moment, and lock the same characteristic beam; According to the same characteristic beam determined at the corresponding moment, confirm the angular characteristics of its detection beam and received beam, and perform characteristic processing, lock the reflection point associated with the same characteristic beam, and record the height data associated with the reflection point; Based on the real-time processing process of the specified area, sequentially confirm the reflection points associated with several same characteristic beams, synchronously lock the height data associated with different reflection points, perform characteristic confirmation on the height data of several reflection points, lock the flatness characteristic value of the specified area and display it.

2. The road surface anti-slip performance detection method based on a laser sensor according to claim 1, wherein The detection laser beam includes several groups of lasers with different wavelengths, and the different wavelengths are all preset parameters.

3. The method for detecting the anti-slip performance of a road surface based on a laser sensor according to claim 1, wherein, The specific method of locking the same characteristic beam is: Based on the received beam received by the laser sensor, confirm the beam waveform associated with the corresponding received beam, lock the zero point from the beam waveform, and the zero point is the point where the waveform point amplitude is 0; Based on the zero points calibrated in sequence from front to back, randomly record the waveform associated with three consecutive zero points as the selected waveform segment, and determine whether this selected waveform segment completely coincides with the selected waveform segments associated before and after; If it exists, record the two completely coincident selected waveform segments as the wavebands to be verified, and calibrate the same characteristic beam by confirming the band characteristics associated with the two wavebands to be verified; If it does not exist, perform waveform verification on the beam waveform of this received beam, lock the interference band, then compare the other bands that do not belong to the interference band with the waveform of the detection beam, confirm the comparison coincidence degree, and based on the confirmation result, lock the detection beam associated with this received beam and perform calibration of the same characteristic beam.

4. The pavement skid resistance performance detection method based on a laser sensor according to claim 3, wherein The method of confirming the band characteristics associated with the two wavebands to be verified is: Confirm the peak points associated with the two wavebands to be verified, then confirm the time interval between the two peak points, and then confirm the wave speed associated with the corresponding beam waveform. Use: wavelength = wave speed × time interval to confirm the wavelength of this beam waveform, and then compare this wavelength with the preset parameters to confirm the detection beam with the same wavelength value, and calibrate the confirmed detection beam and this received beam as the same characteristic beam.

5. The method for detecting the anti-slip performance of a road surface based on a laser sensor according to claim 3, wherein The specific method of performing waveform verification on the beam waveform of this received beam is: Calibrate the zero points of the beam waveform of the received beam. Starting from the first zero point, sequentially record the wavebands associated with three consecutive zero points as the wavebands to be compared. Perform coincidence verification on two adjacent wavebands to be compared, record the non-coincident wavebands as the interference band, record the coincident wavebands as other wavebands, and sequentially confirm each other waveband existing in each waveband to be compared. From the several other wavebands confirmed, select a group of other wavebands with the longest band length as the waveband to be verified; Confirm the maximum amplitude and minimum amplitude of the internal points in the band to be verified, record them as the amplitude range, and confirm the amplitude segment associated with this amplitude range from different detection beams. Denote the amplitude segment with the same amplitude trend as the band to be verified as the same-trend amplitude segment, and randomly select a group from the multiple groups of same-trend amplitude segments associated with a single group of detection beams for coincidence degree verification: confirm the coincidence segment between its same-trend amplitude segment and the band to be verified, and confirm the coincidence ratio based on the line length of the coincidence segment. The coincidence ratio = line length of the coincidence segment ÷ total line length of the band to be verified, and denote the detection beam that satisfies the coincidence ratio ≥ 95% as the pending beam. If there are multiple groups of pending beams, select the pending beam with the largest coincidence ratio value as the same-feature beam of this receiving beam. If there is only one group of pending beams, directly use it as the same-feature beam of this receiving beam.

6. The method for detecting the anti-slip performance of a road surface based on a laser sensor according to claim 5, wherein, If there is no detection beam with a coincidence ratio ≥ 95%, generate an error signal.

7. The method for detecting the anti-skid performance of a road surface based on a laser sensor according to claim 1, wherein The specific method for locking the reflection point is as follows: Based on the confirmed same-feature beam, determine the emission point of its detection beam and the receiving point of the receiving beam; Then confirm the emission angle associated with its detection beam and the receiving angle of the receiving beam. Based on the associated emission point and receiving point, generate the emission line of its detection beam and the receiving line of the receiving beam; Determine the point where its emission line and receiving line intersect, denote the intersecting point as the reflection point associated with the same-feature beam, and confirm the distance between this reflection point and the plane where the laser sensor is located. Denote the confirmed distance as the height data associated with this reflection point.

8. The method for detecting the anti-skid performance of a road surface based on a laser sensor according to claim 7, characterized in that, The specific method for locking the flatness characteristic value is as follows: Based on the different height data associated with different reflection points within the specified area, perform variance processing on several groups of height data to lock the characteristic variance; Use the determined characteristic variance as the flatness characteristic value of this area and display it.

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