A method for ranking the priority of road maintenance in a road network

Abstract

The present invention discloses a method for ranking the priority of road maintenance in a road network, belonging to the field of road maintenance. Based on the depth information and contour information of potholes, the present invention constructs a pothole depth distribution factor and an expansion factor, which are respectively used to characterize the depth distribution and planar distribution of potholes. By collecting the depth distribution factor and the expansion factor corresponding to different times, calculating the change gradient of the pothole depth distribution factor and the change gradient of the expansion factor, the analysis of the evolution law of potholes in both the depth and planar directions is realized, and the development direction and development speed of potholes can be accurately judged, and then the formation reason of potholes can be inferred. Under the condition of limited maintenance funds, the state differences between different roads in the road network can be analyzed more accurately and scientifically, and the decision-making of the road maintenance priority order can be assisted, which can effectively ensure driving safety and reduce maintenance costs.

Description

Technical Field

[0001] The present invention belongs to the technical field of road maintenance, and more specifically, relates to a method for ranking the priorities of road repairs in a road network. Background Art

[0002] A road network is a road system composed of various roads that are interconnected and interwoven in a network distribution within a certain area. The formation and development of the road network are closely related to the development of the city's politics, economy, production, and life. Therefore, maintaining the service performance state of the roads in the road network is a key task of road maintenance.

[0003] Among pavement diseases, potholes are one of the most common and most influential diseases on vehicle driving. Therefore, it is necessary to analyze the distribution status and evolution law of pavement potholes in the road network, formulate reasonable maintenance strategies, and ensure that the roads can maintain a high service state.

[0004] By formulating a reasonable road repair priority plan for the road network, it can not only meet the maintenance goals of road safety, comfort, and durability, orderly improve the overall technical level of the road network, realize the smooth, coordinated, and sustainable development of the road network, but also improve the use efficiency of maintenance funds and the scientific decision-making level, ensure the maximization of the investment benefits of maintenance funds, and realize the transformation from passive maintenance to active and scientific maintenance.

[0005] Currently, during the road network maintenance process, the priority ranking of road repairs is usually based on the maintenance cost, and the work with a lower maintenance cost is ranked in the front position; or based on the subjective experience of decision-makers, the priority ranking is carried out through a certain index that the decision-makers are interested in. Such methods are highly subjective and it is difficult to ensure the optimization of the decision-making effect. At the same time, the evolution law of pavement potholes directly affects the service quality of the road network. In the same road network, there are differences in the distribution and evolution law of potholes on different roads, resulting in differences in the repair priorities of roads. In existing research, insufficient consideration is given to the evolution law of pothole development direction, resulting in the failure to accurately consider the causes of pothole formation during the pothole repair decision-making process, ultimately leading to phenomena such as unreasonable pothole repairs, waste of maintenance funds, and strong subjectivity in the road network repair decision-making plan.

[0006] To address the above problems, the present invention proposes a method for calculating the priority of road repairs in a road network based on the analysis of the evolution law of pavement potholes, ensuring that an optimal maintenance and repair decision-making plan can be made under the condition of limited maintenance funds. Summary of the Invention

[0007] In view of the above deficiencies or improvement requirements of the prior art, the present invention provides a method for ranking the priorities of road repairs in a road network, aiming to improve the scientific nature of the road maintenance and repair decision-making plan, ensure driving safety, and reduce maintenance costs.

[0008] To achieve the above object, the present invention provides a method for ranking the priority of road maintenance in a road network, including: S1. Collecting three-dimensional point cloud information of the road surface and marking the non-pothole area and the pothole area to obtain a three-dimensional matrix L; converting the three-dimensional matrix L into a two-dimensional matrix M containing pothole depth information by means of planar projection;

[0009] S2. Sorting the elements in the two-dimensional matrix M according to the depth size, counting the number of elements corresponding to different depth values, and calculating the proportion of the number of elements corresponding to different depth values to the total number of all elements;

[0010] S3. Assigning weights to the proportions corresponding to different depth values according to the difference in the user's attention to different pothole depths, and calculating the pothole depth distribution factor; the pothole depth distribution factor characterizes the development of potholes in the depth direction;

[0011] S4. Calculating the average area of the edge matrix corresponding to the entire pothole to obtain the pothole expansion factor; the pothole expansion factor characterizes the development of potholes in the planar direction;

[0012] S5. Sequentially collecting the three-dimensional point cloud information of potholes corresponding to different times, and performing steps S1-S4 on the three-dimensional point cloud information of potholes collected at each time to obtain the pothole distribution factor and the pothole expansion factor corresponding to the corresponding time;

[0013] S6. Obtaining the pothole evolution law according to the change gradient of the pothole distribution factor and the change gradient of the pothole expansion factor;

[0014] S7. Performing steps S1-S6 on each road in the road network to obtain the corresponding pothole depth distribution factor and its change gradient, and the pothole expansion factor and its change gradient;

[0015] S8. Using the basic information of each road and the corresponding pothole depth distribution factor and its change gradient, and the pothole expansion factor and its change gradient, to determine the priority order of road maintenance.

[0016] Further, the pothole depth distribution factor is:

[0017]

[0018] Nhi represents the number corresponding to different depth values, S represents the total number of all elements in the two-dimensional matrix, q represents the weight, and h i represents the element corresponding to different depth values.

[0019] Further, the method for constructing the two-dimensional matrix M is as follows:

[0020]

[0021] x and y are coordinates in two directions respectively, z is the vertical axis direction of matrix L, with the positive direction being vertically downward; N is the number of pages of the three-dimensional matrix L, i is the i-th page, i = 1, 2, 3, …, N, and N represents the number of pages of the three-dimensional matrix.

[0022] Further, step S4 specifically includes:

[0023] Extract the i-th page L(x, y, i) of the three-dimensional matrix L in sequence to obtain matrix Li, and extract the edge contour matrix Fi of Li;

[0024] Perform the following operations on matrix Li with matrix B and matrix C respectively:

[0025] Li B = Li[x, y] * B[x, y]

[0026] Li C = Li[x, y] * C[x, y]

[0027] In the formula, * represents the convolution operation, Li B is the new matrix formed by the operation of image matrix Li and matrix B; Li C is the new matrix formed by the operation of image matrix Li and matrix C; matrix B and matrix C represent edge operators;

[0028] Calculate the maximum value at the same position in matrix Li B and Li C to obtain the pit edge matrix Fi;

[0029] Calculate the area A of the pit edge matrix Fi Fi = ∑Fi(x, y);

[0030] Calculate the average area Z of the edge matrix corresponding to the entire pit to obtain the pit expansion factor

[0031] Further, step S8 includes:

[0032] Introduce weights to each influencing factor affecting the road maintenance priority to obtain the weight matrix w; among them, the influencing factors include the number of pits, the pit depth distribution factor, the pit volume expansion factor, the change gradient of the pit depth distribution factor, the change gradient of the pit expansion volume factor, the road width, the road grade, the maintenance cost, the traffic volume, the road age, and the maintenance cycle;

[0033] w = [w1 w2...w j ...w 11

[0034] w j is the weight corresponding to the j-th factor;

[0035] ​Establish a decision matrix \(g\) for different influencing factors in each road:

[0036]

[0037] r jk It represents the ranking position of the road coded as \(c_k\) with the \(j\)-th factor as the ranking object and sorted according to the maintenance priority;

[0038] Establish an optimized ranking matrix \(o\):

[0039]

[0040] o k is the optimal ranking value corresponding to the road coded as \(c_k\);

[0041] Calculate \(o_1\) to \(o\) n and sort them in ascending order to obtain the road maintenance priority order in the road network.

[0042] Furthermore, before executing step S6, the method further includes correcting the pothole depth distribution factor and the expansion factor respectively according to the system error to obtain the pothole corrected depth distribution factor \(U'\) q and the pothole corrected expansion factor \(Z'\).

[0043] Furthermore, the pothole corrected depth distribution factor \(U'\) q and the pothole corrected expansion factor \(Z'\) are:

[0044]

[0045] \(V\) represents the system error.

[0046] Furthermore, step S1 includes:

[0047] Convert the pavement three-dimensional point cloud information into a three-dimensional matrix \(H\); and establish a pothole edge matrix for each layer of the pavement three-dimensional point cloud information;

[0048] Use the matrix formed by the non-zero values in the pothole edge matrix to cut the three-dimensional matrix \(H\) to form a three-dimensional matrix \(J\) representing the circumscribed cuboid of the three-dimensional pothole area;

[0049] Translate the plane \(K\) parallel to the pavement up and down or down and up to intersect with the matrix \(J\), and mark the non-pothole area and the pothole area respectively during the intersection process to obtain a three-dimensional matrix \(L\).

[0050] Generally speaking, compared with the prior art through the above technical solutions conceived by the present invention, the following beneficial effects can be achieved.

[0051] (1) The reasons for the formation of potholes are diverse, including factors such as vehicle driving speed, vehicle load, road materials, and environment. Potholes formed by different causes have different development characteristics, and the corresponding pothole repair measures also vary. Traditional three-dimensional detection methods cannot analyze the development direction of potholes, making it difficult to propose scientific maintenance measures for pothole repair. As a result, the pothole repair effect is poor, diseases recur frequently, and the maintenance cost increases.

[0052] Based on the depth information and contour information of potholes, the present invention constructs a pothole depth distribution factor and an expansion factor, which are respectively used to characterize the depth distribution and planar distribution of potholes. By collecting the depth distribution factor and expansion factor corresponding to different times, calculating the change gradient of the pothole depth distribution factor and the change gradient of the expansion factor, the analysis of the evolution laws of potholes in both the depth and planar directions is realized. It can accurately judge the development direction and development speed of potholes, and then infer the formation reasons of potholes. Under the condition of limited maintenance funds, it can more accurately and scientifically analyze the state differences between different roads in the road network, assist in decision-making on the priority order of road maintenance, and effectively ensure driving safety and reduce maintenance costs.

[0053] (2) The planar projection method proposed by the present invention can project the position information onto a plane, achieving the purpose of reducing the dimension of the pothole matrix. At the same time, the point cloud depth information is retained on the two-dimensional plane matrix in the form of plane matrix elements, realizing the efficient conversion of the three-dimensional pothole matrix into a two-dimensional matrix, and solving the problems of high computer computing power requirements and long calculation time for three-dimensional data processing. At the same time, without increasing the system calculation load, the information in the depth direction of the pothole is considered, improving the accuracy of the analysis.

[0054] (3) The present invention uses mathematical statistics to statistically obtain the distribution frequency and proportion of different pothole depth values, and introduces a weight parameter, which can be used to characterize the weight difference of different pothole depths and reflect the attention degree of maintenance management personnel to pothole depths.

[0055] (4) When calculating the depth distribution factor and the expansion factor, the present invention considers the influence of systematic errors, improving the accuracy of the calculation results. Description of the Drawings

[0056] Figure 1 It is a flowchart of the method for ranking the priority of road maintenance in the road network. Detailed Embodiments

[0057] To make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0058] Combined with Figure 1 , the method of the present invention includes the following steps:

[0059] S1. Collect three-dimensional point cloud information of the road surface and mark the non-pothole area and the pothole area to obtain a three-dimensional matrix L; convert the three-dimensional matrix L into a two-dimensional matrix M containing pothole depth information by means of planar projection;

[0060] Step S1 specifically includes the following processes:

[0061] Collect three-dimensional point cloud information of the road surface, convert it into a three-dimensional matrix H; and establish a pothole edge matrix for each layer of the three-dimensional point cloud information of the road surface;

[0062] Use the matrix formed by non-zero values in the pothole edge matrix to cut the three-dimensional matrix H to form a three-dimensional matrix J representing the circumscribed cuboid of the three-dimensional pothole area; specifically, search for non-zero values in the matrix F to form a new matrix G; use the matrix G to cut the three-dimensional matrix H to form a three-dimensional matrix J, and J is the circumscribed cuboid matrix of the three-dimensional pothole area;

[0063] Translate the plane K parallel to the road surface from top to bottom or from bottom to top to intersect with the matrix J, and mark the non-pothole area and the pothole area respectively during the intersection process to obtain a three-dimensional matrix L; specifically, the translation step size is 1 pixel, and during the intersection process of the plane K and the three-dimensional matrix J, the non-pothole area is marked as 0, and the pothole area is marked as 1. Thus, in the three-dimensional matrix J, a three-dimensional matrix L composed only of 0 and 1 can be obtained;

[0064] Convert the three-dimensional matrix L into a two-dimensional matrix M containing pothole depth information by means of planar projection;

[0065] The above steps establish a three-dimensional matrix of potholes. Since the three-dimensional matrix calculation process has high requirements for computer computing power, occupies a large amount of resources, and has a high calculation cost, the present invention reduces the resource requirements for matrix calculation by converting the three-dimensional matrix of potholes into a two-dimensional matrix.

[0066] In the existing planar projection method, the focus is mainly on the projection of the position information of the point cloud. After the projection is completed, the information in the depth direction of the point cloud is deleted, and only the planar information can be analyzed. In view of this situation, the present invention improves the planar projection method. The planar projection method proposed by the present invention can project the position information onto a plane, achieving the purpose of reducing the dimension of the pothole matrix. At the same time, the depth information of the point cloud is retained on the two-dimensional plane matrix in the form of the elements of the plane matrix.

[0067] Based on the three-dimensional matrix L, a new two-dimensional matrix M is constructed. The construction method is as follows:

[0068]

[0069] In the formula, z is the vertical axis direction of the matrix L, with the downward vertical direction as the positive direction; N is the number of pages of the three-dimensional matrix L, and i is the i-th page; the elements in the two-dimensional matrix represent the depth information of different pothole positions;

[0070] S2. Sort the elements in the two-dimensional matrix M according to the depth size, count the number of elements corresponding to different depth values, and calculate the proportion of the number of elements corresponding to different depth values to the total number of elements;

[0071] Specifically, in the two-dimensional matrix M, each element value represents the depth value of the corresponding position. Since the depth distribution inside the same pothole on the road surface is random and disordered, the arrangement of the sizes of the elements in the two-dimensional matrix M is random. In order to analyze the depth distribution law of the potholes, a mathematical statistics method is adopted. First, the disordered data needs to be converted into ordered data. Therefore, the present invention first sorts the elements in the two-dimensional matrix M according to the depth size, and records them as h1, h2,..., hi..., hn in turn. Among them, if the sizes of multiple element values are the same, only one mark is made: count the number of elements corresponding to different depth values, and record them as Nh1, Nh2,..., Nhn in turn. Calculate the ratio Ti of the number of different depths to the total number S. The calculation method is as follows:

[0072]

[0073] In the formula, Nhi represents the number of matrix element values corresponding to the depth with the sorting value of hi.

[0074] S3. According to the difference in the user's attention to different pothole depths, assign weights to the proportions corresponding to different depth values, and calculate the pothole depth distribution factor; the pothole depth distribution factor characterizes the development of the potholes along the depth direction;

[0075] When analyzing the pothole depth information, there are differences in the attention of different researchers to pothole depths with different proportions. For example, some people are more concerned about the pothole depths with higher occurrence frequencies or larger proportions; while other people may be more concerned about the overall pothole depth distribution. Therefore, the present invention introduces the concept of weight q into the proportion Ti, denoted as the converted proportion Tiz.

[0076]

[0077] When q > 1, it indicates that the attention is higher to the depth values with higher occurrence frequencies inside the pothole;

[0078] When q = 1, it indicates that the attention is the same to the depth values with higher and lower occurrence frequencies inside the pothole; when q < 1, it indicates that the attention is higher to the depth values with lower occurrence frequencies inside the pothole.

[0079] Assigning weights to the proportion of depth values in the present invention helps maintenance personnel to consider the combined weights of the depths when determining the depth values of concern; at the same time, by using the proportion values, the influence of dimensions can be eliminated, the calculation is simple, and the universality of the method is improved.

[0080] The present invention introduces the pothole depth distribution factor U q , which represents the pothole depth distribution situation. The larger this value is, the deeper the overall distribution depth of the pothole; the faster the change speed of this value is, the faster the development along the depth direction. Compared with the traditional pothole characterization indexes (volume, depth), this index takes into account the differences in the attention of road maintenance personnel to different pothole depths, and this index is calculated based on all the collected data, and the calculation result is more accurate, and can accurately reflect the overall depth situation of the entire pothole.

[0081]

[0082] S4. Calculate the average area of the edge matrix corresponding to the entire pothole to obtain the pothole expansion factor;

[0083] The pothole expansion factor Z refers to the development of the pothole along the plane direction. When the expansion factor becomes larger, it means that the pothole develops along the plane. The faster the change speed of the expansion factor is, the faster the expansion speed of the pothole. This index will be used to evaluate the development situation of the pothole in the plane direction.

[0084] 1) Sequentially extract the i-th page L(x, y, i) of the three-dimensional matrix L, denoted as the matrix Li, where i = 1, 2, 3, …, N; extract the edge contour matrix Fi of Li, and the specific method is as follows:

[0085] 2) Establish matrices B and C, respectively as follows:

[0086]

[0087] 3) Perform the following operations on matrix Li with matrix B and matrix C respectively:

[0088] Li B = Li[x, y] * B[x, y]

[0089] Li C = Li[x, y] * C[x, y]

[0090] In the formula, * represents the convolution operation, x and y are the coordinates in two directions respectively, and Li B is the new matrix formed by the operation of image matrix Li and matrix B; Li C is the new matrix formed by the operation of image matrix Li and matrix C.

[0091] 4) Calculate the maximum value at the same position in the Li B and Li C matrices, and establish the pit edge matrix Fi. The calculation process is as follows:

[0092] Fi = Max(Li B , Li C )

[0093] 5) Calculate the area A Fi of the pit edge matrix Fi:

[0094] A Fi = ∑Fi(x, y)

[0095] 6) Calculate the average area Z of the edge matrix corresponding to the entire pit. This index is the expansion factor of the pit:

[0096]

[0097] As a preferred embodiment of the present invention, considering that during the process of the device collecting data, affected by factors such as sensor instability, there will be errors in the system, and the system error V usually follows a Gaussian distribution W, that is:

[0098] V ~ W(μ, σ 2 )

[0099] μ is the mathematical expectation, and σ is the standard deviation.

[0100] Therefore, the present invention uses the Gaussian distribution to correct the pit depth distribution factor and the expansion factor respectively, and obtains the corrected pit depth distribution factor U' q and the corrected expansion factor Z':

[0101]

[0102] S5. Sequentially collect the three-dimensional point cloud information of the pothole corresponding to different times, and perform steps S1 - S4 on the three-dimensional point cloud information of the pothole collected at each time to obtain the pothole distribution factor and the pothole expansion factor corresponding to the time;

[0103] Specifically, collect data at different times, calculate the corresponding modified pothole depth distribution factor and modified expansion factor, calculate the change gradient of the modified depth distribution factor and the change gradient of the modified expansion factor, and analyze the change law of the pothole size as follows:

[0104] 1) Sequentially collect the three-dimensional point cloud information of the pothole corresponding to the times t1, t2,..., tN, repeat steps S1 - S6 to obtain the modified pothole distribution factors U' q1 , U' q2 , …, U' qN , and the modified pothole expansion factors Z1', Z'2, …, Z' N ; Establish the change gradient dU of the pothole distribution factor, and the calculation is as follows:

[0105]

[0106] Δt = t i+1 - t i

[0107] In the formula, Δt is the time interval, t i+1 and t i are the (i + 1)-th moment and the i-th moment respectively, U' qi and U' q(i+1) are the modified pothole distribution factors at the i-th moment and the (i + 1)-th moment respectively.

[0108] Establish the change gradient dZ of the pothole expansion factor, and the calculation is as follows:

[0109]

[0110] S6. Obtain the pothole evolution law according to the change gradient of the pothole distribution factor and the change gradient of the pothole expansion factor.

[0111] Specifically, 1) When dZ > 0 and dU > 0, it indicates that the pothole develops along both the depth direction and the plane direction;

[0112] 2) When dZ > 0 and dU = 0, it indicates that the pothole develops along the depth direction and does not develop along the plane direction;

[0113] 3) When dZ > 0 and dU < 0, it indicates that the pothole develops along the depth direction and contracts along the plane direction;

[0114] 4) When dZ = 0 and dU > 0, it indicates that the pothole does not develop along the depth direction and develops along the plane direction;

[0115] 5) When dZ = 0 and dU = 0, it indicates that the pothole does not develop in the depth direction and does not develop in the plane direction;

[0116] 6) When dZ = 0 and dU < 0, it indicates that the pothole does not develop in the depth direction and contracts in the plane direction;

[0117] 7) When dZ < 0 and dU > 0, it indicates that the pothole becomes shallower in the depth direction and develops in the plane direction;

[0118] 8) When dZ < 0 and dU = 0, it indicates that the pothole becomes shallower in the depth direction and does not develop in the plane direction;

[0119] 9) When dZ < 0 and dU < 0, it indicates that the pothole becomes shallower in the depth direction and contracts in the plane direction.

[0120] S7. Encode the roads in the road network: c1 to cn; n is the number of roads; count the pothole information of each road, and the specific indicators are as follows:

[0121] The number of potholes on each road: e c1 ~e cn ;

[0122] Calculate the pothole depth distribution factor of each road:

[0123]

[0124] U' qci is the pothole depth distribution factor of the ci-th road; e ci is the number of potholes on the ci-th road; U' qcim is the pothole depth distribution factor of the m-th pothole on the ci-th road;

[0125] Calculate the change gradient of the pothole depth distribution factor of each road:

[0126]

[0127] dU ci is the change gradient of the pothole depth distribution factor of the ci-th road; e ci is the number of potholes on the ci-th road; dU cim is the change gradient of the pothole depth distribution factor of the m-th pothole on the ci-th road;

[0128] Calculate the pothole expansion factor of each road:

[0129]

[0130] Z ci is the pothole expansion factor of the ci-th road; eci is the number of potholes on the ci-th road; Z cim is the pothole expansion factor of the m-th pothole on the ci-th road;

[0131] Calculate the change gradient of the pothole expansion factor for each road:

[0132]

[0133] dZ ci is the change gradient of the pothole expansion factor for the ci-th road; e ci is the number of potholes on the ci-th road; dZ cim is the change gradient of the pothole expansion factor of the m-th pothole on the ci-th road.

[0134] In the present invention, the factors to be considered in the process of determining the road maintenance priority in the road network include:

[0135] The number of potholes, pothole depth distribution factor, pothole expansion factor, pothole depth distribution factor change gradient, pothole expansion factor change gradient, road width, road grade, maintenance cost, traffic volume, road age, maintenance cycle, a total of 11 factors;

[0136] For the convenience of description, the above 11 factors are encoded in sequence as: f1~f11;

[0137] Combined with step S7, it can be seen that the roads in the road network are encoded as: c1~cn; n is the number of roads;

[0138] In order to differentially represent the above eleven factors, the weights of each factor are introduced, which are represented in sequence as: w1~w11, and a weight matrix w is established:

[0139] w = [w1 w2...w j ...w 11

[0140] w j is the weight corresponding to the j-th factor.

[0141] Establish a decision matrix g containing 11 factors:

[0142]

[0143] In the matrix, r jk represents the ranking position of the road coded as ck in accordance with the maintenance priority with the j-th factor fj as the ranking object.

[0144] Establish an optimized ranking matrix o:

[0145] ​

[0146] wherein, o k is the optimal sorting value corresponding to the road with road code ck.

[0147] Calculate o1 to o n , and sort them in ascending order, which is the priority order of road maintenance in the road network.

[0148] Those skilled in the art can easily understand that the above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for ranking the priority of road maintenance in a road network, characterized in that, Including: S1. Collect the three-dimensional point cloud information of the road surface and mark the non-pothole area and the pothole area to obtain a three-dimensional matrix L; convert the three-dimensional matrix L into a two-dimensional matrix M containing pothole depth information by means of plane projection; S2. Sort the elements in the two-dimensional matrix M according to the depth size, count the number of elements corresponding to different depth values, and calculate the proportion of the number of elements corresponding to different depth values to the total number of elements; S3. According to the difference in the user's attention to different pothole depths, assign weights to the proportions corresponding to different depth values, and calculate the pothole depth distribution factor; the pothole depth distribution factor characterizes the development of potholes along the depth direction; S4. Calculate the average area of the edge matrix corresponding to the entire pothole to obtain the pothole expansion factor; The pothole expansion factor characterizes the development of potholes along the plane direction; S5. Sequentially collect the three-dimensional point cloud information of the pothole corresponding to different times, and perform steps S1 - S4 on the three-dimensional point cloud information of the pothole collected at each time to obtain the pothole distribution factor and the pothole expansion factor corresponding to the corresponding time; S6. Obtain the pothole evolution law according to the change gradient of the pothole distribution factor and the change gradient of the pothole expansion factor; S7. Perform steps S1 - S6 on each road in the road network to obtain the corresponding pothole depth distribution factor and its change gradient, and the pothole expansion factor and its change gradient; S8. Use the basic information of each road and the corresponding pothole depth distribution factor and its change gradient, and the pothole expansion factor and its change gradient to determine the priority order of road maintenance; The pothole depth distribution factor is: Nhi represents the quantity corresponding to different depth values, S represents the total number of all elements in the two-dimensional matrix, q represents the weight, and h i represents the elements corresponding to different depth values; Step S4 specifically includes: Sequentially extract the i-th page L(x, y, i) of the three-dimensional matrix L to obtain the matrix Li, and extract the edge contour matrix Fi of Li; Perform the following operations on the matrix Li with the matrix B and the matrix C respectively: Li B = Li[x, y] * B[x, y] Li C = Li[x, y] * C[x, y] where * represents the convolution operation, and Li B is the new matrix formed by the operation of the image matrix Li and the matrix B; Li C is the new matrix formed by the operation of the image matrix Li and the matrix C; the matrices B and C represent edge operators; Calculate Li B and Li C The maximum value at the same position in the matrix is obtained to get the pit edge matrix Fi; Calculate the area A of the pothole edge matrix Fi Fi = ∑Fi(x,y); Calculate the average area Z of the edge matrix corresponding to the entire pothole to obtain the pothole expansion factor 2. The method for sorting the priority of road maintenance in a road network according to claim 1, wherein The method for constructing the two-dimensional matrix M is as follows: x and y are the coordinates in two directions respectively, z is the vertical axis direction of the matrix L, and the positive direction is vertically downward; N is the number of pages of the three-dimensional matrix L, i is the i-th page, i = 1, 2, 3,..., N, and N represents the number of pages of the three-dimensional matrix.

3. A method for ranking the priority of road maintenance in a road network according to claim 1, characterized in that Step S8 includes: Introduce weights to each influencing factor affecting the road maintenance priority to obtain a weight matrix w; among them, the influencing factors include the number of potholes, the pothole depth distribution factor, the pothole volume expansion factor, the change gradient of the pothole depth distribution factor, the change gradient of the pothole expansion volume factor, road width, road grade, maintenance cost, traffic volume, road age, and maintenance cycle; w = [w1 w2... w j ... w 11 ​ w j is the weight corresponding to the j-th factor; Establish a decision matrix g of different influencing factors in each road; r jk It represents the ranking position of the road coded as ck with the j-th factor as the ranking object and sorted according to the maintenance priority. Establish an optimized sorting matrix o; o k is the optimal sorting value corresponding to the road with road code ck; Calculate o1 to o n And sort them in ascending order to obtain the priority order of road maintenance in the road network.

4. A method for ranking the priority of road maintenance in a road network according to any one of claims 1-3, characterized in that, Before performing step S6, the method further includes respectively correcting the pothole depth distribution factor and the expansion factor according to the system error to obtain a corrected pothole depth distribution factor U'. q and a corrected pothole expansion factor Z'.

5. A method for ranking the priority of road maintenance in a road network according to claim 4, characterized in that, Pit correction depth distribution factor U' q and the pit correction expansion factor Z' are as follows: V represents the system error.

6. A method for ranking the priority of road maintenance in a road network according to any one of claims 1-3, characterized in that, Step S1 includes: Convert the three-dimensional point cloud information of the road surface into a three-dimensional matrix H; and establish a pothole edge matrix for each layer of the three-dimensional point cloud information of the road surface; Use the matrix formed by the non-zero values in the pothole edge matrix to cut the three-dimensional matrix H to form a three-dimensional matrix J representing the circumscribed cuboid of the three-dimensional pothole area; Translate the plane K parallel to the road surface up or down to intersect with the matrix J, and mark the non-pothole area and the pothole area respectively during the intersection process to obtain the three-dimensional matrix L.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the described program is executed by a processor, it implements the method for ranking the priorities of road maintenance in a road network as described in any one of claims 1-6.

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