Method for detecting road surface skid resistance based on laser sensor

Abstract

The application discloses a road surface anti-skid performance detection method based on a laser sensor and relates to the technical field of road surface flatness inspection. The application solves the problem that the confirmed flatness data error is large due to the error of the same characteristic light speed confirmation, generates a multi-wavelength detection laser beam through preset parameters in the wavelength confirmation link, combines a unique waveform analysis strategy, realizes accurate determination of the wavelength of the received light beam, locks the waveform section through zero points, distinguishes normal and interference wave sections through coincidence verification, effectively eliminates the influence of interference waves on wavelength confirmation, quickly locks the same characteristic light beam through amplitude interval comparison and coincidence degree verification in a complex interference environment, greatly improves the accuracy and reliability of wavelength confirmation, and reduces the misjudgment caused by interference.

Description

Technical Field

[0001] This invention relates to the field of road surface smoothness inspection technology, specifically a method for detecting the anti-skid performance of road surfaces based on laser sensors. Background Technology

[0002] With the rapid development of transportation, road surface skid resistance has become a key factor affecting road traffic safety. Traditional methods for testing road surface skid resistance, such as the pendulum test and the lateral force coefficient test, are mostly contact-based tests, which have problems such as low testing efficiency, significant traffic interference, and easy equipment wear, making it difficult to meet the needs of modern transportation for rapid road surface testing.

[0003] Patent application (CN113487663B) discloses a method for calculating the surface texture depth based on laser 3D data, mainly comprising the following: 1. A line laser 3D scanning device scans the surface to obtain 3D data of the scanned area; 2. The depth matrix is ​​divided into small regions of a certain size, and the maximum value and position of each region are extracted. Based on these maximum points, the griddata function is used for interpolation to obtain the MTD calculation baseline matrix RS; 3. Based on the 3D data, the griddata function is used for interpolation 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 scanned area. This invention's method for calculating surface texture depth fully utilizes complete 3D surface data, effectively avoids external noise interference, provides accurate calculations, has high computational efficiency, and offers intuitive 3D display, providing effective data for intelligent assessment of surface skid resistance performance and realizing intelligent 3D surface detection and assessment.

[0004] Based on the ground detection data of the corresponding laser sensor, the detection data associated with the corresponding laser sensor is confirmed. However, in the actual processing, the laser is easily interfered with by other light waves, resulting in a large difference between the actual received beam and the emitted beam. The lack of a setting for rapid confirmation of the same characteristics of the received and emitted beams leads to errors in the confirmation process due to the speed of light with the same characteristics, resulting in large errors in the confirmed flatness data and failing to achieve a more accurate processing effect. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for detecting the anti-skid performance of road surfaces based on laser sensors, which solves the problem that errors in the confirmed smoothness data are easily caused by the error of confirming the same characteristic light speed.

[0006] To achieve the above objectives, the present invention provides a method for detecting the anti-skid performance of road surfaces based on laser sensors, comprising the following steps:

[0007] A detection laser beam is generated based on preset parameters, and the wavelength of the received beam is confirmed based on the received beam associated with the corresponding time, locking onto beams with the same characteristics. The specific method is as follows:

[0008] Based on the received beam received by the laser sensor, the beam waveform associated with the corresponding received beam is confirmed, and the zero point is locked from the beam waveform. The zero point is the point where the waveform amplitude is 0.

[0009] Based on the zero points marked sequentially from front to back, the waveforms associated with three consecutive sets of zero points are randomly recorded as selected waveform segments, and it is determined whether this selected waveform segment completely overlaps with the selected waveform segments associated with the preceding and following points.

[0010] If they exist, the two completely overlapping selected waveform segments are recorded as the bands to be verified. By confirming the band characteristics associated with the two bands to be verified, the beams with the same characteristics are calibrated: the peak points associated with the two bands to be verified are confirmed, the time interval between the two peak points is confirmed, and the wave velocity associated with the corresponding beam waveform is confirmed. The wavelength of this beam waveform is confirmed by using: wavelength = wave velocity × time interval. This wavelength is then compared with the preset parameters to confirm the existence of a detection beam with the same wavelength value. The confirmed detection beam and this receiving beam are calibrated as beams with the same characteristics.

[0011] If not, the waveform of the received beam is verified to identify the interfering band. Then, the waveforms of other bands not belonging to the interfering band are compared with the waveform of the probe beam to confirm the overlap. Based on the confirmation result, the probe beam associated with this received beam is identified, and the beam with the same characteristics is calibrated.

[0012] The zero point of the received beam waveform is calibrated. Starting from the first zero point, the bands associated with three consecutive sets of zero points are recorded as the comparison waves. The overlap of two adjacent sets of comparison waves is checked. The non-overlapping bands are recorded as interference bands, and the overlapping bands are recorded as other bands. The other bands existing in each comparison wave are confirmed in turn. From the confirmed other bands, the group of other bands with the longest band length is selected as the verification band.

[0013] Confirm the maximum and minimum amplitude values ​​of points within the band to be verified, and record them as amplitude ranges. Identify the amplitude segments associated with this amplitude range from different probe beams. Record the amplitude segments with the same amplitude trend as the band to be verified as the same trend amplitude segments. Randomly select one set of same trend amplitude segments associated with a single probe beam for overlap verification: confirm the overlap between the same trend amplitude segments and the band to be verified, and confirm the overlap ratio based on the line length of the overlap segment. The overlap ratio = line length of the overlap segment ÷ line length of the band to be verified. Record the probe beams that meet the overlap ratio ≥ 95% as undetermined beams. If there are multiple undetermined beams, select the undetermined beam with the largest overlap ratio as the same characteristic beam of this receiving beam. If there is only one undetermined beam, directly use it as the same characteristic beam of this receiving beam.

[0014] If there are no probe beams with an overlap ratio of ≥95%, an error signal is generated;

[0015] Based on the characteristic beams determined at the corresponding time, the angular characteristics of the detection and reception beams are confirmed, and feature processing is performed to lock the reflection points associated with the characteristic beams. The height data associated with the reflection points is recorded. The specific method is as follows:

[0016] Based on the confirmed beams of the same characteristics, determine the emission point of the detection beam and the receiving point of the receiving beam.

[0017] Then confirm the emission angle associated with its probe beam and the reception angle of its receiver beam, and generate the emission line of its probe beam and the reception line of its receiver beam based on the associated emission point and receiver point.

[0018] Determine the point where the transmitting and receiving lines intersect, record the intersection point as the reflection point associated with the 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.

[0019] Based on the real-time processing of a specified area, several reflection points associated with the same characteristic beam are sequentially confirmed, and the height data associated with different reflection points are simultaneously locked. The height data of several reflection points are then feature-confirmed, and the flatness feature value of the specified area is locked and displayed. The specific method is as follows:

[0020] Based on the confirmed beams of the same characteristics, determine the emission point of the detection beam and the receiving point of the receiving beam.

[0021] Then confirm the emission angle associated with its probe beam and the reception angle of its receiver beam, and generate the emission line of its probe beam and the reception line of its receiver beam based on the associated emission point and receiver point.

[0022] Determine the point where the transmitting and receiving lines intersect, and record the intersection point as the reflection point associated with the characteristic beam. 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.

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

[0024] This invention provides a method for detecting the anti-skid performance of road surfaces based on laser sensors. Compared with existing technologies, it has the following advantages:

[0025] This invention achieves accurate determination of the wavelength of the received beam by generating a multi-wavelength probe laser beam through preset parameters in the wavelength confirmation stage and combining it with a unique waveform analysis strategy. By using zero-value points to lock waveform segments and distinguishing between normal and interference bands through overlap verification, it not only effectively eliminates the influence of interference waves on wavelength confirmation, but also can quickly lock beams with the same characteristics in complex interference environments through amplitude range comparison and overlap verification, which greatly improves the accuracy and reliability of wavelength confirmation and reduces misjudgments caused by interference.

[0026] Based on the emission and reception angles of beams with the same characteristics, and combined with the emission and reception point information, the position of the reflection point is accurately determined and the height data is recorded. This method is based on geometric principles to build a calculation model, which greatly improves the accuracy of reflection point positioning compared with traditional methods, and provides a reliable data foundation for subsequent flatness analysis. Attached Figure Description

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

[0028] Figure 2 This is a schematic diagram illustrating the determination of the reflection point in this invention. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Please see Figure 1 This application provides a method for detecting the anti-skid performance of road surfaces based on laser sensors, including the following steps:

[0031] Step 1: Generate a detection laser beam based on preset parameters. The detection laser beam includes several sets of lasers with different wavelengths. These different wavelengths are preset parameters, determined in advance by the operator based on experience, to facilitate subsequent beam confirmation. Based on the receiving beam associated with the corresponding moment, the wavelength of the receiving beam is confirmed to lock the beam with the same characteristics. Specifically, the beam with the same characteristics refers to the detection laser and the receiving laser associated with the same moment. Lasers with the same wavelength are the corresponding beams with the same characteristics. During the verification process, the wavelength can generally be directly verified to lock the wavelength of the corresponding receiving beam. Alternatively, filtering processing is required. For specific waveforms with interference waves, the associated interference waves are removed to determine the corresponding wavelength.

[0032] 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, the beam waveform associated with the corresponding received beam is confirmed, and the zero point is locked from the beam waveform. The zero point is the point where the waveform amplitude is 0.

[0034] Based on the zero-value points marked sequentially from front to back, the waveforms associated with three consecutive sets of zero-value points are randomly selected as selected waveform segments. It is then determined whether this selected waveform segment completely overlaps with the selected waveform segments associated with the preceding and following segments (the selected waveform segments associated with the preceding and following segments also correspond to the bands associated with the three consecutive sets of zero-value points; that is, in this verification process, there are nine zero-value points. If one set overlaps with the preceding and following bands during verification, it indicates a complete overlap). This random process includes several selection processes, not just one selection that ends, but continues until an overlapping waveform segment is found. If it cannot be determined, then the waveform segment does not exist (the specific handling measures for non-existent waveform segments are detailed in the second subsection below).

[0035] If they exist, the two completely overlapping selected waveform segments are recorded as the test segments. The peak points associated with the two test segments are confirmed, the time interval between the two peak points is confirmed, and the wave velocity associated with the corresponding beam waveform is confirmed (this value can be directly obtained from the laser sensor). The wavelength of this beam waveform is confirmed by using: wavelength = wave velocity × time interval. This wavelength is then compared with the preset parameters to confirm the existence of a detection beam with the same wavelength value. The confirmed detection beam and this received beam are calibrated as beams with the same characteristics. If no beam of the same wavelength is found, an error is reported directly, indicating that the interference level is too severe or there is a problem with the corresponding laser sensor. Under normal circumstances, such problems will not occur.

[0036] If it does not exist, then the waveform of the received beam is verified to lock the interference band. Then, other bands that do not belong to the interference band are compared with the waveform of the detection beam to confirm the degree of overlap. Based on the confirmation result, the detection beam associated with this received beam is locked and the beam with the same characteristics is calibrated. Specifically, if the waveform of the beam with the corresponding wavelength cannot be confirmed, it is considered to be in an interference state, which makes it impossible to confirm the specific waveform segment of the overlapping waveform. In order to find the associated detection beam more accurately, the waveform comparison is performed to achieve the specific confirmation of the corresponding beam with the same characteristics.

[0037] The detailed processing method for waveform verification is as follows:

[0038] The zero points of the received beam waveform are calibrated. Starting from the first zero point, the wavebands associated with three consecutive sets of zero points are denoted as the comparison waves (there is a corresponding waveform segment between three zero points, and the corresponding waveform segment is a comparison wave; for example, if the zero points are 1, 2, 3, ..., n, then the three zero points 1, 2, and 3 are associated with a comparison wave, the three zero points 4, 5, and 6 are also associated with a comparison wave, and so on, with subsequent consecutive three zero points associated with a comparison wave). (Group of waves to be compared) The two adjacent groups of waves to be compared are checked for overlap. The non-overlapping bands are recorded as interference bands, and the overlapping bands are recorded as other bands. The other bands existing in each wave to be compared are confirmed in turn. From the confirmed other bands, the group of other bands with the longest band length is selected 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, they can be selected randomly).

[0039] Identify the maximum and minimum amplitude values ​​of points within the band to be verified, and record them as amplitude intervals. Identify the amplitude segments associated with this amplitude interval from different probe beams. Record amplitude segments with the same amplitude trend as the band to be verified as "same-trend amplitude segments." Randomly select one set of same-trend amplitude segments associated with a single probe beam for overlap verification: confirm the overlap between the same-trend amplitude segments and the band to be verified, and determine the overlap ratio based on the line length of the overlap segment. The overlap ratio = line length of the overlap segment ÷ line length of the band to be verified. Record probe beams that satisfy an overlap ratio ≥ 95% as "same-trend amplitude segments." If there are multiple sets of beams to be determined, the beam with the largest overlap ratio is selected as the beam with the same characteristics as the receiving beam. If there is only one set of beams to be determined, it is directly used as the beam with the same characteristics as the receiving beam. Specifically, not all bands in the corresponding receiving beam are interfered with, but some bands are not interfered with. Therefore, the corresponding bands are checked for overlap to identify the overlapping bands and lock the non-interfered bands. Then, from the identified non-interfered bands, the band with the longest length value is selected as the most characteristic to confirm the overall characteristics.

[0040] From the several emitted probe beams, the overlap verification of characteristic bands is performed. Since the wavelength associated with each band is different, its trend characteristics are also different. After the corresponding overlap verification process, the probe beam associated with the corresponding receiving beam can be quickly locked, so as to quickly lock the beam with the same characteristics, which is convenient for subsequent specific verification of the flatness of the plane.

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

[0042] Step 2: Based on the characteristic beams determined at the corresponding time, confirm the angular characteristics of the detection beam and the receiving beam, perform feature processing, lock the reflection point associated with the characteristic 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 is received, 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 facilitates the subsequent specific confirmation of flatness.

[0043] The specific method for locking the reflection point is as follows:

[0044] Based on the confirmed beams of the same characteristics, determine the emission point of the detection beam and the receiving point of the receiving beam.

[0045] Then confirm the emission angle associated with its probe beam and the reception angle of its receiver beam, and generate the emission line of its probe beam and the reception line of its receiver beam based on the associated emission point and receiver point.

[0046] Determine the point where the transmitting and receiving lines intersect, record the intersection point as the reflection point associated with the 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 Figure 2 Based on the plane where the laser sensor is located, the corresponding transmission and reception points are identified, and the corresponding transmission and reception angles are simultaneously identified. The corresponding transmission line and the corresponding reception line can be locked. There is a two-dimensional intersection point between the transmission line and the reception line. The two-dimensional intersection point is the corresponding reflection point. Based on the location of the plane, the distance associated with the corresponding reflection point can be effectively determined, thereby locking the corresponding height data.

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

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

[0050] The determined feature variance is used as the flatness feature value of this area and displayed for external personnel to view. The larger the corresponding flatness feature value, the less flat the corresponding area is. The smaller the corresponding feature variance value, the flatter the corresponding area is. Operators can assess the flatness status of the corresponding area based on the specific feature values.

[0051] Some of the data in the above formulas are numerical calculations with dimensions removed, and the contents not described in detail in this specification are all prior art known to those skilled in the art.

[0052] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. A method for detecting road surface skid resistance performance based on laser sensors, characterized in that, Includes the following steps: A detection laser beam is generated based on preset parameters, and the wavelength of the received beam is confirmed based on the received beam associated with the corresponding time, locking onto beams with the same characteristics. The specific method is as follows: Based on the received beam received by the laser sensor, the beam waveform associated with the corresponding received beam is confirmed, and the zero point is locked from the beam waveform. The zero point is the point where the waveform amplitude is 0. Based on the zero points marked sequentially from front to back, the waveforms associated with three consecutive sets of zero points are randomly recorded as selected waveform segments, and it is determined whether this selected waveform segment completely overlaps with the selected waveform segments associated with the preceding and following points. If they exist, the two sets of completely overlapping selected waveform segments are recorded as the bands to be verified. By confirming the band characteristics associated with the two sets of bands to be verified, the beams with the same characteristics are calibrated. If it does not exist, then the waveform of the received beam is verified to lock the interference band. Then, the waveform of other bands that do not belong to the interference band is compared with the waveform of the detection beam to confirm the comparison overlap. Based on the confirmation result, the detection beam associated with this received beam is locked and the beam with the same characteristics is calibrated. Based on the beam of the same characteristic determined at the corresponding time, the angular characteristics of its detection beam and receiving beam are confirmed, and feature processing is performed to lock the reflection point associated with the beam of the same characteristic and record the height data associated with the reflection point. Based on the real-time processing of the specified area, the reflection points associated with several beams of the same characteristic are confirmed in sequence, the height data associated with different reflection points are locked synchronously, the height data of several reflection points are confirmed as features, and the flatness feature value of the specified area is locked and displayed.

2. The method for detecting road surface skid resistance performance based on a laser sensor according to claim 1, characterized in that, The detection laser beam includes several groups of lasers with different wavelengths, all of which are preset parameters.

3. The method for detecting road surface skid resistance performance based on a laser sensor according to claim 1, characterized in that, The method for confirming the band characteristics associated with the two sets of bands to be verified is as follows: Confirm the peak points associated with the two sets of wavebands to be verified, then confirm the time interval between the two sets of peak points, and then confirm the wave velocity associated with the corresponding beam waveform. Use the formula: wavelength = wave velocity × time interval to confirm the wavelength of this beam waveform. Then compare this wavelength with the preset parameters to confirm the existence of a detection beam with the same wavelength value. Certify the confirmed detection beam and this received beam as beams with the same characteristics.

4. The method for detecting road surface skid resistance performance based on a laser sensor according to claim 1, characterized in that, The specific method for waveform verification of the received beam is as follows: The zero point of the received beam waveform is calibrated. Starting from the first zero point, the bands associated with three consecutive sets of zero points are recorded as the comparison waves. The overlap of two adjacent sets of comparison waves is checked. The non-overlapping bands are recorded as interference bands, and the overlapping bands are recorded as other bands. The other bands existing in each comparison wave are confirmed in turn. From the confirmed other bands, the group of other bands with the longest band length is selected as the verification band. Identify the maximum and minimum amplitude values ​​of points within the band to be verified and record them as amplitude ranges. Identify the amplitude segments associated with this amplitude range from different probe beams. Record the amplitude segments with the same amplitude trend as the band to be verified as the same trend amplitude segments. Randomly select one set of same trend amplitude segments associated with a single probe beam for overlap verification: confirm the overlap between the same trend amplitude segments and the band to be verified, and determine the overlap ratio based on the line length of the overlap segment. The overlap ratio = line length of the overlap segment ÷ line length of the band to be verified. Record the probe beams that meet the overlap ratio ≥ 95% as undetermined beams. If there are multiple undetermined beams, select the undetermined beam with the largest overlap ratio as the same characteristic beam of this receiving beam. If there is only one undetermined beam, directly use it as the same characteristic beam of this receiving beam.

5. The method for detecting road surface skid resistance performance based on a laser sensor according to claim 4, characterized in that, If there are no probe beams with an overlap ratio of ≥95%, an error signal is generated.

6. The method for detecting road surface skid resistance performance based on a laser sensor according to claim 1, characterized in that, The specific method for locking the reflection point is as follows: Based on the confirmed beams of the same characteristics, determine the emission point of the detection beam and the receiving point of the receiving beam. Then confirm the emission angle associated with its probe beam and the reception angle of its receiver beam, and generate the emission line of its probe beam and the reception line of its receiver beam based on the associated emission point and receiver point. Determine the point where the transmitting and receiving lines intersect, and record the intersection point as the reflection point associated with the characteristic beam. 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.

7. The method for detecting road surface skid resistance performance based on a laser sensor according to claim 6, characterized in that, The specific method for locking the flatness feature value is as follows: Based on the different height data associated with different reflection points within a specified area, several sets of height data are processed for variance to lock the characteristic variance; the determined characteristic variance is used as the flatness characteristic value of this area and displayed.

Images