Road structure deformation measurement system under cyclic load effect

Abstract

The invention relates to the technical field of deformation measurement, and provides a road structure deformation measurement system under a cyclic load effect. The system comprises a load loading system, a measuring disc, a deformation sensing unit and a deformation information extraction unit, the load loading system is used for applying a cyclic load perpendicular to the horizontal plane to the measuring disc and outputting a cyclic load signal to the outside; the measuring disc is used for generating vertical movement under the action of cyclic load; the deformation sensing unit is used for acquiring the speed and acceleration of vertical motion; the deformation information extraction unit is used for obtaining a road structure deformation quantity according to the cyclic load signal, the speed and the acceleration; the road structure comprises a road surface and a roadbed. The invention provides a roadbed or pavement deformation quantity measuring method capable of accurately simulating the driving load effect and the pavement structure constraint, so that the accurate dynamic resilience modulus of the road structure is further obtained.

Description

Technical Field

[0001] The present application relates to the technical field of deformation measurement, and in particular to a road structure deformation measurement system under cyclic load. Background Art

[0002] The dynamic rebound modulus of road structure, that is, the ratio of stress to strain of road structure under load, is a core parameter in the design of road structures including roadbed and pavement. Its size has a significant impact on the design and mechanical response of road structure. Therefore, objectively obtaining the dynamic rebound modulus of road structure is the key to conducting research on the theory and methods of durable road design.

[0003] At present, the in-situ tests of the rebound modulus of road structures mainly include the load-bearing plate method, Beckman beam method, drop weight deflectometer method and portable drop weight deflectometer method. The results measured by the load-bearing plate method and the Beckman beam method are both static rebound modulus, which have problems such as low detection efficiency and labor consumption. The loads applied by the drop weight deflectometer method and the portable drop weight deflectometer method are both impact loads. Although the measured results are dynamic rebound modulus under a certain load, since the impact load is a one-time load, the effect on the road structure is significantly different from the effect of repeated traffic loads on the road structure. It is difficult to accurately simulate the actual stress state of the roadbed or pavement under the repeated traffic load and the constraints of the road structure, resulting in inaccurate measurement results of the dynamic rebound modulus of the road structure. Summary of the invention

[0004] The embodiment of the present application provides a road structure deformation measurement system under cyclic loads, which is used to solve the technical problem that the existing impact load is a one-time load, and the effect on the road structure is significantly different from the effect of repeated traffic loads on the road structure, making it difficult to accurately simulate the actual stress state of the roadbed or pavement under the action of repeated traffic loads and road structure constraints, thereby resulting in inaccurate measurement results of the dynamic rebound modulus of the road structure.

[0005] The embodiment of the present application provides a road structure deformation measurement system under cyclic load, including: a load loading system, a measuring disc, a deformation sensing unit and a deformation information extraction unit; The load loading system is used to apply a cyclic load perpendicular to the horizontal plane to the measuring disc and output a cyclic load signal to the outside; The measuring disc is used to generate vertical movement under the action of the cyclic load; The deformation sensing unit is used to obtain the speed and acceleration of the vertical movement; The deformation information extraction unit is used to obtain the road structure deformation according to the cyclic load signal, the speed and the acceleration; the road structure includes a road surface and a roadbed.

[0006] In one embodiment, the deformation sensing unit includes at least one Doppler velocimeter and at least two acceleration sensors; The Doppler velocimeter is used to obtain the speed of the vertical movement, and the acceleration sensor is used to obtain the acceleration of the vertical movement; The projected laser of the Doppler velocimeter is perpendicular to the horizontal plane, and the measuring point of the Doppler velocimeter is located at the first preset position of the measuring disc; The acceleration sensors are arranged at a second preset position of the measuring disc, and the acceleration sensors are evenly distributed on the measuring disc.

[0007] In one embodiment, obtaining the road structure deformation according to the cyclic load signal, the speed and the acceleration includes: Determining a cyclic load stable loading period of the measuring disk according to the cyclic load signal; Determining whether the measuring disc meets the vibration balance requirement according to a plurality of accelerations acquired by the at least two acceleration sensors during the stable loading period of the cyclic load; If the vibration balance requirement is met, the vibration period and vibration phase of the measuring disk are obtained according to the target acceleration in the stable loading period of the cyclic load; the target acceleration is the acceleration obtained by the acceleration sensor closer to the measuring point among the at least two acceleration sensors; Obtaining a relative displacement of the Doppler velocimeter relative to the measuring point according to the velocity acquired by the Doppler velocimeter during the stable loading period of the cyclic load; Classifying and identifying the relative displacement according to the vibration period and the vibration phase to obtain a road structure deformation signal that conforms to the vibration period and the vibration phase; According to the stable load signal in the stable loading period of the cyclic load and the road structure deformation signal, a deformation amplitude matching the load amplitude is obtained.

[0008] In one embodiment, determining the cyclic load stable loading period of the measuring disk according to the cyclic load signal comprises: According to a preset load loading frequency and a preset number of load cycles, the cyclic load signal is divided into units to obtain a plurality of signal units; If the load peak value and load valley value in each load cycle in any signal unit meet the consistency requirement, and the difference between the load peak mean value and the load valley mean value meets the preset condition, then the time period covered by any signal unit is determined to be the cyclic load stable loading time period unit of the measuring disk; The cyclic load stable loading period units of the measuring disc are combined to obtain the cyclic load stable loading period of the measuring disc.

[0009] In one embodiment, determining whether the measuring disc meets the vibration balance requirement according to the multiple accelerations acquired by the at least two acceleration sensors during the stable loading period of the cyclic load includes: Calculating the average value of the amplitudes of the multiple accelerations obtained by each acceleration sensor; Calculate the ratio of the minimum value to the maximum value in the mean values ​​of each amplitude to obtain the vibration balance of the measuring disc; If the vibration balance is greater than or equal to the balance threshold, it is determined that the measuring disc meets the vibration balance requirement.

[0010] In one embodiment, obtaining the vibration period and vibration phase of the measuring disk according to the target acceleration in the stable loading period of the cyclic load includes: Integrating the target acceleration according to the sampling frequency of the target acceleration to obtain a motion trajectory curve of the measuring disk; The vibration period and the vibration phase of the measuring disk are obtained according to the peak position of the motion trajectory curve, the trough position of the motion trajectory curve and the sampling frequency of the target acceleration.

[0011] In one embodiment, obtaining the relative displacement of the Doppler velocimeter relative to the measuring point according to the velocity acquired by the Doppler velocimeter during the stable loading period of the cyclic load includes: The velocity is integrated according to the sampling frequency of the velocity to obtain the relative displacement of the Doppler velocimeter relative to the measuring point.

[0012] In one embodiment, obtaining a deformation amplitude matching the load amplitude according to the stable load signal and the road structure deformation signal in the stable loading period of the cyclic load includes: According to a preset load loading frequency, obtaining a first wave peak and a first wave valley of the stable load signal; The difference between the adjacent first wave peak and the first wave valley is determined as the load amplitude; According to a preset load loading frequency, obtaining a second wave peak and a second wave trough of the road structure deformation signal; The difference between the adjacent second wave peak and the second wave valley is determined as the deformation amplitude; According to the time difference between the first wave crest and the second wave crest and the time difference between the first wave trough and the second wave trough, a deformation amplitude matching the load amplitude is obtained.

[0013] In one embodiment, before determining the cyclic load stable loading period of the measuring disk according to the cyclic load signal, the method includes: According to the motion continuity characteristics of the measuring disc, the sudden change data in the cyclic load signal, the velocity and the acceleration are eliminated.

[0014] In one embodiment, before determining the cyclic load stable loading period of the measuring disk according to the cyclic load signal, the method includes: According to the difference of the vibration amplitude of the measuring disk obtained by different measuring sensors, combined with the preset amplitude difference threshold, it is judged whether the working state of the measuring sensor is abnormal; The measuring sensors include a plurality of acceleration sensors and a Doppler velocimeter.

[0015] The road structure deformation measurement system under cyclic load provided by the present application includes a load loading system, a measuring disc, a deformation sensing unit and a deformation information extraction unit. The load loading system is used to apply a cyclic load perpendicular to the horizontal plane to the measuring disc and output a cyclic load signal to the outside. The measuring disc is used to generate vertical movement under the action of the cyclic load. The deformation sensing unit is used to obtain the speed and acceleration of the vertical movement. The deformation information extraction unit is used to obtain the road structure deformation according to the cyclic load signal, speed and acceleration. Among them, the road structure includes a pavement and a roadbed. The present application applies a cyclic load perpendicular to the horizontal plane to the measuring disc through a load loading system, so that the measuring disc moves vertically, so that the cyclic load can be used to simulate the repeated traffic load borne by the road structure, and the vertical deformation of the road structure under the repeated traffic load is simulated by the movement of the vertical movement, and then the deformation of the road structure is obtained according to the cyclic load signal of the load loading system and the speed and acceleration of the measuring disc, that is, the strain of the road structure under the stress state is obtained, and then the dynamic modulus of resilience of the road structure can be calculated in combination with the strain when the cyclic load size of the load loading system, that is, the stress size, is obtained. Since the present application can accurately simulate the actual stress state of the roadbed or pavement under the action of repeated traffic loads and road structure constraints, it can measure and obtain accurate road structure deformation, and further obtain accurate road structure dynamic modulus of resilience. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present application or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is one of the flow diagrams of measuring the road structure deformation amount by the road structure deformation measurement system under cyclic load provided in the embodiment of the present application; Figure 2 This is the second flow chart of measuring the road structure deformation amount by the road structure deformation measurement system under cyclic load provided in the embodiment of the present application; Figure 3 This is the third flow chart of measuring the road structure deformation amount by the road structure deformation measurement system under cyclic load provided in the embodiment of the present application; Figure 4 This is the fourth flow chart of the road structure deformation measurement system under cyclic load provided in the embodiment of the present application for measuring the road structure deformation amount. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0019] It should be noted that in the description of the embodiments of the present application, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements. The orientation or position relationship indicated by the terms "upper", "lower" and the like is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be a connection between the two elements. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0020] The terms "first", "second", etc. in this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0021] The embodiment of the present application provides a road structure deformation measurement system under cyclic load, which may include: a load loading system, a measuring disc, a deformation sensing unit and a deformation information extraction unit; The load loading system is used to apply a cyclic load perpendicular to the horizontal plane to the measuring disc and output a cyclic load signal to the outside; The measuring disc is used to produce vertical movement under the action of cyclic loads; The deformation sensing unit is used to obtain the speed and acceleration of vertical movement; The deformation information extraction unit is used to obtain the road structure deformation according to the cyclic load signal, velocity and acceleration; the road structure includes the pavement and the roadbed.

[0022] Among them, the load loading system includes a load loading device, which can be an air compressor, a hydraulic press or other mechanism, which is not limited here. The device is used to apply a cyclic load perpendicular to the horizontal plane to the measuring disc according to a preset load loading frequency and load loading size.

[0023] It should be noted that when the road is in the roadbed construction stage and the road surface has not yet been formed, the system of this embodiment can be used to accurately measure the roadbed deformation, and then combined with the cyclic load size of the load loading system to obtain an accurate roadbed dynamic rebound modulus; when the road is in the completion stage or service stage, the system of this embodiment can be used to accurately measure the road surface deformation, and then combined with the cyclic load size of the load loading system to obtain an accurate road surface dynamic rebound modulus.

[0024] The road structure deformation measurement system under cyclic load provided in this embodiment includes a load loading system, a measuring disc, a deformation sensing unit and a deformation information extraction unit. The load loading system is used to apply a cyclic load perpendicular to the horizontal plane to the measuring disc and output a cyclic load signal to the outside. The measuring disc is used to generate vertical movement under the action of the cyclic load. The deformation sensing unit is used to obtain the speed and acceleration of the vertical movement. The deformation information extraction unit is used to obtain the road structure deformation according to the cyclic load signal, speed and acceleration. Wherein, the road structure includes a pavement and a roadbed. In this embodiment, a cyclic load perpendicular to the horizontal plane is applied to the measuring disc by a load loading system, so that the measuring disc moves vertically, so that the cyclic load can be used to simulate the repeated traffic load borne by the road structure, and the vertical deformation of the road structure under the repeated traffic load is simulated by the movement of the vertical movement, and then the deformation of the road structure is obtained according to the cyclic load signal of the load loading system and the speed and acceleration of the measuring disc, that is, the strain of the road structure under the stress state is obtained, and then the dynamic modulus of resilience of the road structure can be calculated in combination with the strain when the cyclic load size of the load loading system, that is, the stress size, is obtained. Since this embodiment can accurately simulate the actual stress state of the roadbed or road surface under the action of repeated traffic loads and road structure constraints, it can measure and obtain accurate road structure deformation, and further obtain accurate road structure dynamic modulus of resilience.

[0025] In one embodiment, the deformation sensing unit includes at least one Doppler velocimeter and at least two acceleration sensors; The Doppler velocimeter is used to obtain the velocity of vertical motion, and the accelerometer is used to obtain the acceleration of vertical motion; The projected laser of the Doppler velocimeter is perpendicular to the horizontal plane, and the measuring point of the Doppler velocimeter is located at a first preset position of the measuring disk; The acceleration sensors are arranged at the second preset positions of the measuring disc, and the acceleration sensors are evenly distributed on the measuring disc.

[0026] The load loading system, the measuring disc, the deformation sensing unit and the deformation information extraction unit are all located on the vehicle-carrying platform. Furthermore, the Doppler velocimeter is directly connected to the vehicle-carrying platform, and the acceleration sensor is arranged on the measuring disc.

[0027] The first preset position is a preset position on the measuring disk at a distance from the center of the measuring disk, and a certain error range is accepted, that is, the measuring point of the Doppler velocimeter can be located on the measuring disk at a distance from the center of the measuring disk. The position within the range, where is the first preset distance from the center of the measuring disk, Similarly, the second preset position is also a preset position on the measuring disk from the center of the measuring disk, and accepts a certain error range, that is, the acceleration sensor can be located on the measuring disk from the center of the measuring disk The position within the range, where is the second preset distance from the center of the measuring disk, is the second error.

[0028] It should be noted that there may be multiple Doppler velocimeters, in which case the measuring points of the multiple Doppler velocimeters should be evenly distributed on the measuring disc. In addition, during the measurement process, the measuring disc is not affected by other forces of the vehicle platform except the force of the cyclic load.

[0029] In addition, the measurement system may also include a thermometer for acquiring the temperature of the road structure, ie, the roadbed or the road surface.

[0030] This embodiment uses a Doppler velocimeter to obtain the speed of the vertical movement of the measuring disc, and uses an acceleration sensor to obtain the acceleration of the vertical movement of the measuring disc. During the measurement process, this embodiment obtains multiple uniformly distributed acceleration signals of the measuring disc, evaluates the fit between the measuring disc and the road surface or roadbed during the measurement process, and determines whether the current measurement is a valid measurement, thereby ensuring the reliability of the measurement result; this embodiment uses multiple Doppler velocimeters to obtain the speed of the vertical movement of the measuring disc corresponding to multiple measuring points, thereby facilitating the acquisition of multiple vertical displacements of the measuring disc for mutual verification, thereby further improving the accuracy of the measurement result.

[0031] Figure 1 This is one of the flow charts of measuring the road structure deformation amount by the road structure deformation measurement system under cyclic load provided in the embodiment of the present application; Figure 1 In one embodiment, obtaining the road structure deformation according to the cyclic load signal, velocity and acceleration may include: 101. Determine a cyclic load stable loading period of the measuring disk according to the cyclic load signal; 102. Determine whether the measuring disc meets the vibration balance requirement according to a plurality of accelerations acquired by at least two acceleration sensors during a stable loading period of the cyclic load; 103. If the vibration balance requirement is met, the vibration period and vibration phase of the measuring disk are obtained according to the target acceleration during the stable loading period of the cyclic load; The target acceleration is the acceleration obtained by the acceleration sensor closer to the measuring point among the at least two acceleration sensors; 104. According to the velocity obtained by the Doppler velocimeter during the stable loading period of the cyclic load, the relative displacement of the Doppler velocimeter relative to the measuring point is obtained; 105. Classify and identify the relative displacement according to the vibration period and the vibration phase, and obtain a road structure deformation signal that conforms to the vibration period and the vibration phase; 106. According to the stable load signal and the road structure deformation signal in the stable loading period of the cyclic load, the deformation amplitude matching the load amplitude is obtained.

[0032] In step 101, the cyclic load stable loading period is a period when the waveform of the cyclic load signal is relatively stable; In step 102, the vibration balance of the disc is measured, that is, the similarity of the vibration amplitudes of points on the disc that are close to the center of the disc is measured, which is used to reflect the degree of fit between the disc and the roadbed or road surface.

[0033] Since the Doppler velocimeter in the measurement system is located on the vehicle platform, when the measurement system is working, the Doppler velocimeter itself and the vehicle platform will vibrate and generate vibration noise. At this time, the measurement result of the Doppler velocimeter contains vibration velocity noise, and then in the process of obtaining the deformation, it is necessary to eliminate the influence of vibration noise on the measurement result. When the vibration amplitude values ​​of the points on the measuring disc close to the center of the circle are relatively similar during the period when the waveform of the cyclic load signal is stable, it means that the measuring disc fits well with the roadbed or road surface under the action of the cyclic load. The cyclic load at this time can simulate the repeated driving load more realistically, so that the deformation in this state is more similar to the deformation under the driving load. At the same time, the noise generated by the vibration of the Doppler velocimeter itself in this state can also be more advantageously eliminated, thereby improving the accuracy of the measurement results. Therefore, it is necessary to first determine the stable loading period of the cyclic load and determine that the measuring disc meets the vibration balance requirements, and then use the velocity and acceleration in the stable loading period of the cyclic load to calculate the deformation of the road structure.

[0034] In step 103 to step 105, since the target acceleration is the acceleration obtained by the acceleration sensor closer to the measuring point among the at least two acceleration sensors, the vibration period and vibration phase of the measuring disk obtained by integrating the target acceleration can be well matched with the vibration period and vibration phase of the measuring disk obtained by the Doppler velocimeter at the measuring point, so that the relative displacement can be classified and identified according to the vibration period and vibration phase, and then the road structure deformation signal that conforms to the vibration period and vibration phase can be obtained. Among them, the classification and identification can be performed using a machine learning algorithm.

[0035] It should be noted that in step 103, if the vibration balance requirement is not met, the current measurement is invalid and the current measuring point needs to be remeasured (such as re-placing the measuring disc and then measuring) until the vibration balance requirement is met.

[0036] In step 106, the load amplitude can be used to characterize the stress on the road structure, and the deformation amplitude can be used to characterize the strain of the road structure under the cyclic load, so that the dynamic modulus of elasticity of the road structure can be calculated based on the corresponding relationship between the two.

[0037] In practical applications, there is no strict timing relationship between step 103 and step 104; that is, they can be executed simultaneously, or any one of the steps can be executed first, depending on actual needs and is not limited here.

[0038] In this embodiment, the stable loading period of the cyclic load is first determined, and it is determined that the measuring disc meets the vibration balance requirement, so that the subsequent calculation is located in a scenario where the measuring disc fits well with the roadbed or road surface under the cyclic load, and then the corresponding relationship between the vibration period and the vibration phase and the relative displacement is used to realize the classification and identification of the relative displacement, and obtain an accurate road structure deformation signal, and further obtain an accurate load amplitude and a deformation amplitude matching it based on the stable load signal.

[0039] Figure 2 This is a second flow chart of the road structure deformation measurement system under cyclic load provided in the embodiment of the present application for measuring the road structure deformation; Figure 2 In one embodiment, determining the cyclic load stable loading period of the measuring disk according to the cyclic load signal may include: 201. According to a preset load loading frequency and a preset number of load cycles, the cyclic load signal is divided into units to obtain a plurality of signal units; 202. If the load peaks and load valleys in each load cycle in any signal unit meet the consistency requirement, and the difference between the load peak mean and the load valley mean meets the preset condition, then the period covered by the signal unit is determined to be a cyclic load stable loading period unit of the measuring disk; 203. Combine the cyclic load stable loading period units of the measuring disc to obtain the cyclic load stable loading period of the measuring disc.

[0040] In step 201, the load loading frequency in each signal unit is a preset load loading frequency, and each includes a preset number of load cycles.

[0041] In step 202, i.e., in each load cycle of each signal unit, the difference between the load peaks is less than the preset threshold value. T p , the difference between the load valley values ​​is less than the preset threshold T v , and the difference between each load peak and each load valley is less than the preset threshold T dAt this time, the time period covered by the signal unit can be considered as a unit in the stable loading period of the cyclic load.

[0042] In step 203, all the units are merged, that is, the entire cyclic load stable loading period.

[0043] In this embodiment, the cyclic load signal is first divided into units with the same frequency and number of cycles, and then the peak and trough stability of each unit is screened, from which the time period units of the cyclic load stable loading are screened, and finally all the time period units of stable loading are summed up to obtain the total cyclic load stable loading time period. Due to the refined time period division and the judgment and screening for each time period unit, all unstable time period units can be eliminated to the maximum extent, so that the final stable loading time period is more accurate.

[0044] Figure 3 This is a schematic diagram of the third process of measuring the road structure deformation amount by the road structure deformation measurement system under cyclic load provided in the embodiment of the present application; Figure 3 In one embodiment, determining whether the measuring disc meets the vibration balance requirement according to the multiple accelerations acquired by at least two acceleration sensors during the stable loading period of the cyclic load may include: 301. Calculate the average value of the amplitudes of multiple accelerations acquired by each acceleration sensor respectively; 302. Calculate the ratio of the minimum value to the maximum value in the mean values ​​of each amplitude to obtain the vibration balance of the measuring disk; 303. If the vibration balance is greater than or equal to the balance threshold, it is determined that the measuring disc meets the vibration balance requirement.

[0045] If the vibration of the measuring disc is relatively balanced, it means that the acceleration amplitudes obtained by the acceleration sensors uniformly distributed at a distance close to the center of the circle are relatively close, and the average amplitude of the acceleration obtained by each acceleration sensor is also relatively close. Furthermore, the minimum and maximum values ​​of the amplitude averages are also relatively close. If the vibration balance is greater than or equal to the balance threshold, that is, the ratio of the minimum value to the maximum value is greater than or equal to the balance threshold, that is, the ratio of the maximum value to the minimum value is less than or equal to the balance threshold, that is, the maximum value and the minimum value are close enough, it can be considered that the vibration of the measuring disc is relatively balanced, that is, the measuring disc meets the vibration balance requirements.

[0046] In this embodiment, since the vibration of the measuring disk obtained by each acceleration sensor has multiple vibration cycles, the amplitude average is calculated for each of the multiple accelerations obtained by each acceleration sensor, and then the difference between the maximum value and the minimum value is measured by comparing the ratio of the minimum value and the maximum value of the amplitude average with the balance threshold, and then when the difference between the maximum value and the minimum value is small, it is determined that the vibration balance requirement is met. Since the vibration balance measurement standard includes the calculation and consideration of multiple accelerations of multiple acceleration sensors, the evaluation result is more accurate.

[0047] In one embodiment, obtaining the vibration period and vibration phase of the measuring disk according to the target acceleration in the stable loading period of the cyclic load may include: According to the sampling frequency of the target acceleration, the target acceleration is integrated to obtain the motion trajectory curve of the measuring disk. According to the peak position and trough position of the motion trajectory curve and the sampling frequency of the target acceleration, the vibration period and vibration phase of the measuring disk are obtained.

[0048] Further, obtaining the relative displacement of the Doppler velocimeter relative to the measuring point according to the velocity obtained by the Doppler velocimeter during the stable loading period of the cyclic load may include: According to the sampling frequency of the velocity, the velocity is integrated to obtain the relative displacement of the Doppler velocimeter relative to the measuring point.

[0049] The relative displacement of the Doppler velocimeter to the measuring point of the measuring disc is real-time, and the real-time relative displacement includes the relative displacement caused by the vertical displacement of the measuring disc itself and the relative displacement caused by the vibration of the Doppler velocimeter with the vehicle platform.

[0050] In this embodiment, the target acceleration is integrated in the time domain to obtain a complete motion curve of the measuring disk during the stable loading period of the cyclic load. Since the stable complete curve can more completely characterize the characteristic changes of the waveform, the vibration period and vibration phase of the measuring disk obtained through the peak and trough positions and the sampling frequency of the curve can also be more accurate. Similarly, the speed measured by the Doppler velocimeter is integrated in the time domain to obtain a complete and accurate relative displacement of the Doppler velocimeter relative to the measuring point during the stable loading period of the cyclic load. Combined with the vibration period and vibration phase of the measuring disk, the road structure deformation can be accurately separated from the complete relative displacement, so as to obtain an accurate dynamic rebound modulus of the road structure in subsequent calculations.

[0051] Figure 4 This is a fourth flow chart of the road structure deformation measurement system under cyclic load provided in the embodiment of the present application for measuring the road structure deformation; Figure 4In one embodiment, obtaining a deformation amplitude matching the load amplitude according to a stable load signal and a road structure deformation signal in a stable loading period of a cyclic load may include: 401. Obtain a first wave peak and a first wave valley of a stable load signal according to a preset load loading frequency; 402. Determine the difference between the adjacent first wave peak and the first wave valley as the load amplitude; 403. According to a preset load loading frequency, a second wave peak and a second wave valley of the road structure deformation signal are obtained; 404. Determine the difference between the adjacent second wave peak and the second wave valley as the deformation amplitude; 405. According to the time difference between the first wave crest and the second wave crest and the time difference between the first wave trough and the second wave trough, a deformation amplitude matching the load amplitude is obtained.

[0052] In actual applications, there is no strict timing relationship between step 401 and step 403; that is, they can be executed simultaneously, or any one step can be executed first, depending on actual needs and is not limited here, but step 402 must be executed after step 401, and step 404 must be executed after step 403.

[0053] This embodiment first extracts the amplitude of the stable load signal and the road structure deformation signal within the stable loading period of the cyclic load, and then performs temporal alignment based on the time difference between the peaks and troughs of the two signals, so as to make the amplitudes of the two signals correspond one-to-one in time, thereby obtaining the load amplitude and deformation amplitude that correspond one-to-one in time, which can be directly used to calculate the dynamic rebound modulus of the road structure at the corresponding time.

[0054] In one embodiment, before determining the cyclic load stable loading period of the measuring disk according to the cyclic load signal, the method may include: According to the motion continuity characteristics of the measuring disk, the sudden changes in the cyclic load signal, velocity and acceleration are eliminated.

[0055] This embodiment eliminates mutation data of key indicators acquired before formally measuring the deformation variables, which can reduce the impact of abnormal data on subsequent calculations, make subsequent calculations more accurate, and improve the accuracy of the road structure deformation variables, thereby improving the accuracy of the dynamic rebound modulus of the road structure.

[0056] In one embodiment, before determining the cyclic load stable loading period of the measuring disk according to the cyclic load signal, the method may include: According to the difference of vibration amplitudes of the measuring disc obtained by different measuring sensors and the preset amplitude difference threshold, it is judged whether the working state of the measuring sensor is abnormal; The measuring sensors include several accelerometers and Doppler velocimeters.

[0057] Specifically, the mean values ​​of the vibration amplitudes of the measuring disks obtained by different measuring sensors can be sorted to obtain a sorted amplitude mean sequence, and then the median of the amplitude mean sequence can be used as a reference value to calculate the difference between the mean value of the vibration amplitudes of the measuring disks obtained by all measuring sensors and the reference value, and the sensor corresponding to the amplitude mean whose absolute value of the difference is greater than the difference threshold is marked as having an abnormal working state.

[0058] This embodiment obtains the vibration amplitude of the measuring disk through multiple measuring sensors, and then performs abnormal screening based on the difference between the mean and median of the vibration amplitude obtained by each measuring sensor. This can effectively screen out a small number of measuring sensors whose measurement results seriously deviate from the overall measurement results of multiple measuring sensors, so that they can be calibrated or eliminated to avoid their influence on subsequent measurement calculation processes.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A road structure deformation measurement system under cyclic load, characterized in that: include: Load loading system, measuring disc, deformation sensing unit and deformation information extraction unit; The load loading system is used to apply a cyclic load perpendicular to the horizontal plane to the measuring disc and output a cyclic load signal to the outside; The measuring disc is used to generate vertical movement under the action of the cyclic load; The deformation sensing unit is used to obtain the speed and acceleration of the vertical movement; The deformation information extraction unit is used to obtain the road structure deformation according to the cyclic load signal, the speed and the acceleration; the road structure includes a road surface and a roadbed.

2. The road structure deformation measurement system under cyclic load according to claim 1 is characterized in that: The deformation sensing unit includes at least one Doppler velocimeter and at least two acceleration sensors; The Doppler velocimeter is used to obtain the speed of the vertical movement, and the acceleration sensor is used to obtain the acceleration of the vertical movement; The projected laser of the Doppler velocimeter is perpendicular to the horizontal plane, and the measuring point of the Doppler velocimeter is located at the first preset position of the measuring disc; The acceleration sensors are arranged at a second preset position of the measuring disc, and the acceleration sensors are evenly distributed on the measuring disc.

3. The road structure deformation measurement system under cyclic load according to claim 2 is characterized in that: The obtaining of the road structure deformation according to the cyclic load signal, the speed and the acceleration comprises: Determining a cyclic load stable loading period of the measuring disk according to the cyclic load signal; Determining whether the measuring disc meets the vibration balance requirement according to a plurality of accelerations acquired by the at least two acceleration sensors during the stable loading period of the cyclic load; If the vibration balance requirement is met, the vibration period and vibration phase of the measuring disk are obtained according to the target acceleration in the stable loading period of the cyclic load; the target acceleration is the acceleration obtained by the acceleration sensor closer to the measuring point among the at least two acceleration sensors; Obtaining a relative displacement of the Doppler velocimeter relative to the measuring point according to the velocity acquired by the Doppler velocimeter during the stable loading period of the cyclic load; Classifying and identifying the relative displacement according to the vibration period and the vibration phase to obtain a road structure deformation signal that conforms to the vibration period and the vibration phase; According to the stable load signal in the stable loading period of the cyclic load and the road structure deformation signal, a deformation amplitude matching the load amplitude is obtained.

4. The road structure deformation measurement system under cyclic load according to claim 3 is characterized in that: The step of determining the cyclic load stable loading period of the measuring disk according to the cyclic load signal comprises: According to a preset load loading frequency and a preset number of load cycles, the cyclic load signal is divided into units to obtain a plurality of signal units; If the load peak value and load valley value in each load cycle in any signal unit meet the consistency requirement, and the difference between the load peak mean value and the load valley mean value meets the preset condition, then the time period covered by any signal unit is determined to be the cyclic load stable loading time period unit of the measuring disk; The cyclic load stable loading period units of the measuring disc are combined to obtain the cyclic load stable loading period of the measuring disc.

5. The road structure deformation measurement system under cyclic load according to claim 3 is characterized in that: The determining whether the measuring disc meets the vibration balance requirement according to the multiple accelerations acquired by the at least two acceleration sensors during the stable loading period of the cyclic load comprises: Calculating the average value of the amplitudes of the multiple accelerations obtained by each acceleration sensor; Calculate the ratio of the minimum value to the maximum value in the mean values ​​of each amplitude to obtain the vibration balance of the measuring disc; If the vibration balance is greater than or equal to the balance threshold, it is determined that the measuring disc meets the vibration balance requirement.

6. The road structure deformation measurement system under cyclic load according to claim 3, characterized in that: The step of obtaining the vibration period and the vibration phase of the measuring disk according to the target acceleration in the stable loading period of the cyclic load comprises: Integrating the target acceleration according to the sampling frequency of the target acceleration to obtain a motion trajectory curve of the measuring disk; The vibration period and the vibration phase of the measuring disk are obtained according to the peak position of the motion trajectory curve, the trough position of the motion trajectory curve and the sampling frequency of the target acceleration.

7. The road structure deformation measurement system under cyclic load according to claim 3, characterized in that: The step of obtaining the relative displacement of the Doppler velocimeter relative to the measuring point according to the velocity obtained by the Doppler velocimeter during the stable loading period of the cyclic load comprises: The velocity is integrated according to the sampling frequency of the velocity to obtain the relative displacement of the Doppler velocimeter relative to the measuring point.

8. The road structure deformation measurement system under cyclic load according to claim 3 is characterized in that: The step of obtaining a deformation amplitude matching the load amplitude according to the stable load signal in the stable loading period of the cyclic load and the road structure deformation signal comprises: According to a preset load loading frequency, obtaining a first wave peak and a first wave valley of the stable load signal; The difference between the adjacent first wave peak and the first wave valley is determined as the load amplitude; According to a preset load loading frequency, obtaining a second wave peak and a second wave trough of the road structure deformation signal; The difference between the adjacent second wave peak and the second wave valley is determined as the deformation amplitude; According to the time difference between the first wave crest and the second wave crest and the time difference between the first wave trough and the second wave trough, a deformation amplitude matching the load amplitude is obtained.

9. The road structure deformation measurement system under cyclic load according to claim 3, characterized in that: Before determining the cyclic load stable loading period of the measuring disk according to the cyclic load signal, the method includes: According to the motion continuity characteristics of the measuring disc, the sudden change data in the cyclic load signal, the velocity and the acceleration are eliminated.

10. The road structure deformation measurement system under cyclic load according to claim 3, characterized in that: Before determining the cyclic load stable loading period of the measuring disk according to the cyclic load signal, the method includes: According to the difference of the vibration amplitude of the measuring disk obtained by different measuring sensors, combined with the preset amplitude difference threshold, it is judged whether the working state of the measuring sensor is abnormal; The measuring sensors include a plurality of acceleration sensors and a Doppler velocimeter.

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