Method and associated system for estimating the international roughness index of a road segment

Abstract

The present invention relates to a method for estimating an International Roughness Index (IRI) of a road or road segment, comprising a preparatory step (1) and an International Roughness Index estimation step (10). The preparatory step (1) comprises estimating values ​​of the vehicle tire damping and stiffness coefficients (C t , K t ) and (2) collecting known International Roughness Index values ​​or known road profiles (profiles r ) is related to the vehicle vertical acceleration value (Az 車両 ) and the measured vertical acceleration value (Az 車両 (3) collecting vehicle georeference data and speed data indicative of a given constant speed, the speed data being associated with the vehicle georeference data and the vehicle speed.

Description

[Technical field]

[0001] The present invention relates generally to the automotive and road pavement monitoring sector. More specifically, the present invention relates to a system and method for estimating the International Roughness Index (IRI). In particular, according to an aspect of the present invention, an estimate of the IRI is determined as a function of physical quantities related to the motion of the vehicle, such as vertical acceleration, and physical quantities related to the vehicle itself, such as damping and stiffness coefficients of the vehicle's suspension and tires mounted on the vehicle.

[0002] The invention may be applied to either any type of road vehicle used to transport people, such as passenger cars, buses, campervans, or any type of road vehicle used to transport products, such as industrial vehicles (trucks, tractor trailers, etc.) or light or medium sized commercial vehicles (such as vans).Without loss of generality, reference is made to motor vehicles fitted with internal combustion engines and / or hybrid and / or electric vehicles, such as one or more passenger cars and / or buses and / or trucks and / or motorbikes. [Background technology]

[0003] As is known, road pavements must be designed to ensure a rolling surface that is approximately regular and largely deformation-free in order to meet the requirements regarding safety and comfort for the vehicles driven on said roads. Indeed, the impact of a vehicle wheel against / on an obstacle (such as a pothole or dent) on the road pavement can damage the tire of the wheel, in particular its carcass (i.e. casing). For example, an outward bulge of the tire sidewall typically indicates that a cord has broken in the carcass due to the impact against / on an obstacle, since running over objects such as dents and holes can break individual cords. If a damaged tire (e.g. a tire with several broken cords) is not detected immediately and therefore not repaired / replaced promptly, there is a risk of completely damaging / destroying the carcass of the tire and even damaging the wheel rim and / or the suspension if the driver continues to drive with the damaged tire (e.g. if the damaged tire further impacts against / on other obstacles).

[0004] Recently, periodic monitoring of the regularity / smoothness level of individual roads is occasionally carried out, mainly for the purpose of planning maintenance works. Typically, such monitoring is based on the calculation of the International Roughness Index (IRI), which is the most commonly used roughness index for road pavement irregularity. The IRI is typically obtained by measuring a longitudinal road profile (more specifically, the longitudinal profile of the road pavement height), in particular by using a quarter-car vehicle mathematical model (also known as the quarter-car model (abbreviated as QCM)) or a full-car vehicle mathematical model (also known as the full-car model (abbreviated as FCM)), the response of which is accumulated to yield a roughness index with units of slope (in / m, m / km, etc.).

[0005] Unfortunately, IRI measurements are quite expensive in practice and difficult to implement on a large scale across corporately managed road networks.

[0006] Therefore, there is a significant need for innovative technological solutions in the automotive and road pavement monitoring sectors that can detect road pavement irregularities / unevenness earlier and more easily.

[0007] For example, one example of a known solution is disclosed in patent application WO 2020 / 225699, which discloses a method and system for recognizing unevenness in road pavement. In particular, WO 2020 / 225699: a) a preliminary testing step, which comprises, in sequence: - carrying out the test by running and / or impacting the pneumatic tire over different bumps at different vehicle speeds, - acquiring vertical acceleration during the test (conveniently at a sampling rate of at least 10 Hz); and - constructing at least a first model for relating the standard deviation of the vertical acceleration for the performed tests to the roughness of the pavement; the preliminary testing step including: b) an actual recognition step, which comprises, in sequence: - acquiring said vertical acceleration (conveniently at a sampling rate of at least 10 Hz), - performing high-pass filtering of the vertical acceleration, preferably with a minimum filtering threshold of 0.1 Hz or less, the high-pass filtering being performed on reference sections of pavement of variable length having a linear length of 2 to 25 meters, preferably a linear length of 5 to 10 meters; - processing said vertical acceleration by a Fast Fourier Transform (FFT); - calculating the standard deviation of the processed vertical acceleration by FFT at relevant frequencies, the relevant frequencies preferably comprising a first vibration frequency range of a suspension system of the motor vehicle, the first vibration frequency range being between 1.5 Hz and 3 Hz; and - recognizing the presence and size of irregularities in the pavement based on a comparison between the first model and the standard deviation of the vertical acceleration processed by the FFT at the relevant frequencies; The actual recognition step includes: The present invention relates to a method comprising the steps of:

[0008] According to WO 2020 / 225699, the relevant frequencies advantageously comprise a second vibration frequency range of the vehicle chassis, and step b) advantageously further comprises the sub-steps of obtaining information regarding the vehicle position by means of a GPS signal and of locating any irregularities based on the vehicle position, and step a) advantageously further comprises the sub-steps of carrying out the tests by running and / or impacting different types of tyres on different types of motor vehicles, and of building a number of models to relate the standard deviation of the vertical acceleration to tyre type and / or motor vehicle.

[0009] Additionally, according to WO 2020 / 225699, step a) preferably comprises the following sub-steps: - acquiring the wheel speeds and the vehicle speed during the test performed and calculating a normalized wheel speed for the test performed by the ratio between the wheel speed of the vehicle and the corresponding respective vehicle speed; and - constructing at least one second model to relate the standard deviation of the normalized wheel speeds to roughness of the pavement. Also includes.

[0010] Finally, according to WO 2020 / 225699, said step b) preferably comprises the following sub-steps: - obtaining a steering angle at a wheel of the vehicle; - obtaining a steering angle at a wheel of said vehicle by FFT, - determining a minimum threshold within the frequency components of the steering angle at the wheel processed by the FFT, - obtaining wheel speeds; - obtaining a speed of said vehicle; - calculating said normalized wheel speeds according to the ratio between said wheel speeds and the respective corresponding speeds of the vehicle; - performing a high-pass filtering of said wheel speeds or said normalized wheel speeds by applying said minimum threshold value; - calculating a standard deviation of said normalized wheel speeds; Including, The sub-step of recognising the presence of an irregularity in the pavement advantageously includes using both a comparison between the first model and the standard deviation of vertical acceleration processed by FFT at the relevant frequency, and a comparison between the second model and the standard deviation of the normalised wheel speed. Summary of the Invention

[0011] Considering the above, the Applicant felt the need to carry out an in-depth investigation to try to develop an innovative technological solution that allows for a faster and simpler quantification of road pavement roughness, in particular an estimation of IRI, that is easier to perform and can be performed more frequently than traditional IRI measurements, thus arriving at the present invention.

[0012] Therefore, the object of the present invention is to provide a technical solution for performing a faster and simpler quantification of road pavement roughness, in particular an estimation of IRI, which is easier to perform and can be performed more frequently than conventional IRI measurements.

[0013] This and other objects are achieved by the present invention, as it relates to a system and method for estimating an IRI, as defined in the appended claims.

[0014] In order that the invention may be better understood, preferred embodiments, intended merely as non-limiting examples, will now be described with reference to the accompanying drawings (all not to scale): [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 shows a schematic diagram of the preparatory steps of an IRI estimation method according to a preferred embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram illustrating an IRI estimation step of the IRI estimation method according to a preferred embodiment of the present invention. [Diagram 3] FIG. 2 shows a schematic diagram of a preparatory step of determining parameters for a vehicle; [Figure 4] FIG. 2 shows a schematic diagram of the trend of vertical acceleration values ​​over different road profiles; [Diagram 5] FIG. 2 shows a schematic diagram of one preparatory step of validating parameters for a vehicle; [Figure 6] FIG. 2 shows a schematic plot illustrating the correlation of root mean square values ​​of vehicle vertical acceleration values ​​obtained according to a real road profile and a digitized road profile; [Figure 7] FIG. 10 is a schematic diagram illustrating a plot correlating IRI values ​​with root mean square values ​​of vehicle vertical acceleration values ​​at different constant vehicle speeds. [Figure 8] FIG. 1 is a schematic diagram illustrating a preferred embodiment of an IRI estimation system. [Figure 9] FIG. 1 is a schematic diagram illustrating a preferred embodiment of an IRI estimation system. [Figure 10] FIG. 1 is a schematic diagram illustrating a preferred embodiment of an IRI estimation system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The present invention will now be described in detail with reference to the accompanying drawings so that those skilled in the art can make and use the present invention. Various modifications of the described embodiments will be readily apparent to those skilled in the art, and the general principles described may be applied to other embodiments and applications without departing from the scope of the present invention as defined in the appended claims. Therefore, the present invention should not be considered as being limited to the embodiments described and shown herein, but should be accorded the widest scope of protection consistent with the features described and claimed.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly used by a person having ordinary experience in the field related to the present invention. In case of conflict, the present description, including the definitions provided, is binding. Furthermore, the examples are provided for illustrative purposes only and should not be considered as limiting.

[0018] In particular, the block diagrams contained in the attached drawings and described below are not intended as representations of structural characteristics or structural limitations, but rather as representations of functional characteristics, i.e., inherent characteristics of a device, which must be defined by the effects obtained or functional constraints, and which may be implemented in various ways, so as to preserve the functionality (ability to function) of the device.

[0019] To facilitate an understanding of the embodiments described herein, reference will be made to certain specific embodiments and specific language will be used to describe the same. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.

[0020] The invention particularly relates to a method for estimating the International Roughness Index (IRI) as a function of physical quantities related to the motion of the vehicle, such as vertical acceleration, and physical quantities related to the vehicle itself, such as the damping and stiffness coefficients of the vehicle's suspension and of the tires mounted on the vehicle.

[0021] 1 and 2, the method according to the invention comprises a preparation step 1 and an IRI estimation step 10. Furthermore, in the following, reference is made to one or more cars and / or buses and / or trucks and / or motorbikes, etc., equipped with an internal combustion engine and / or hybrid and / or electric vehicles.

[0022] In particular, Figure 1 shows a schematic diagram of a preparatory step 1 of the method for estimating an IRI according to the present invention. In detail, the preparatory step 1 includes: - vehicle tire damping and stiffness coefficient values ​​C of one or more tires (not shown) of one or more motor vehicles t , K t (Block 2) and - a) a known International Roughness Index value or a known first road profile, profile r a first vehicle vertical acceleration value Az measured on one or more vehicles driven at one or more given constant speeds along one or more roads or road segments to which 車両 and, b) the first measured vertical acceleration value Az 車両 a first vehicle georeference data associated with the vehicle; c) the first measured vertical acceleration value Az 車両 a first vehicle speed data indicating a given constant speed associated with the (Block 3) and - the value C of the coefficient of damping and stiffness of the first vehicle tire t , K t , first vehicle georeference data, first vehicle speed data, and a first vehicle vertical acceleration value Az 車両 Based on the second road profile, profile d (Block 4) Includes.

[0023] Preparation step 1 is - Second road profile, profile d A second vehicle vertical acceleration value Az based on 出力- f(c, k), the second vertical acceleration value Az 出力 - the second vehicle georeferenced data of f(c, k), the first measured vertical acceleration value Az 車両 and a second vehicle speed data indicating a given constant speed associated with the vehicle tire damping and stiffness coefficient value C. t , K t (Block 5) - vehicle suspension damping and stiffness coefficient values ​​C of one or more suspensions of one or more vehicles; s , K s (Block 6) - first and second vehicle vertical acceleration values ​​Az 車両 , Az 出力 - determining the first and second root mean square values ​​of f(c, k), respectively (block 7); - known International Roughness Index value or first road profile, profile r , the second vehicle vertical acceleration value Az 出力 a second vehicle vertical acceleration value Az based on the second root mean square value of f(c, k), the second vehicle georeference data, and the second vehicle speed data; 出力 - determining one or more vehicle transfer functions that are mathematically related to the second root mean square value of f(c,k) and the International Roughness Index value at a given constant speed (block 8); Further includes:

[0024] 2 shows a schematic diagram of an IRI estimation step 10 of the method for estimating an IRI according to the present invention. In particular, the IRI estimation step 10 comprises the steps of: - obtaining a third vehicle vertical acceleration value Az measured for a given vehicle driven at a driving speed on a given road or road segment, third vehicle georeference data associated with the third vehicle vertical acceleration value Az, and third vehicle speed data indicative of the given driving speed of the vehicle (block 11); - calculating a third root mean square value of a third vehicle vertical acceleration value Az (block 12); - estimating an International Roughness Index (IRI) value for the given road or road segment based on the one or more vehicle transfer functions determined in the preparatory step 1 and on the third root mean square value of the third vehicle vertical acceleration value Az and the associated third vehicle georeference data and the third vehicle speed data (block 13); Includes.

[0025] According to an aspect of the invention, the third vehicle georeference data of a given vehicle is namely data indicating the 2D / 3D position, for example the GPS position, of the given vehicle.

[0026] According to an aspect of the present invention, the first vehicle vertical acceleration value Az 車両 , the first vehicle georeference data, and the first vehicle speed data, r For one or more vehicles of one and the same given vehicle type and / or one and the same given vehicle model, driven at one or more given constant speeds along one or more roads or road segments, for which a second road profile, profile d is specific to a given vehicle type and / or model.

[0027] According to another aspect of the present invention, the first vehicle vertical acceleration value Az 車両 , first vehicle georeference data and first vehicle speed data are collected in steps a), b) and c) for each of one or more motor vehicles of different given vehicle types and / or different given vehicle models. Further, a second road profile, profile d is specific to each given vehicle type and / or model.

[0028] Therefore, according to an aspect of the present invention, the International Roughness Index value is estimated by using a vehicle transfer function specific to the vehicle type / model of the given motor vehicle determined in the preparation step 1 (block 13).

[0029] Referring again to FIG. 1, in a preparation step 1, a vehicle tire damping and stiffness coefficient C t , K t is determined through tire testing, for example a dedicated deflection test.

[0030] Further, according to an aspect of the present invention, the first vehicle vertical acceleration value Az 車両 The step of collecting the first vehicle georeference data and the first vehicle speed data (Block 3) includes vehicle telemetry data acquisition, where the vehicle acquires a first vehicle vertical acceleration value Az at a predetermined acquisition frequency. 車両 and a data logger unit for acquiring the first vehicle georeferenced data as a GPS position of the vehicle. Furthermore, the telemetry data is automatically transmitted to a remote computing system (e.g., a cloud computing system) via a wireless connection (e.g., based on 2G, 3G, 4G, or 5G cellular technology). In particular, the acquisition frequency for the first vehicle georeferenced data is, for example, greater than 1 Hz. Furthermore, the first vehicle vertical acceleration value Az 車両 To determine, the vehicle travels along a road of known shape (i.e., for example, a first road profile, profile r More specifically, the first vehicle vertical acceleration value Az 車両 The acquisition frequency is 10 Hz or higher. Additionally, the vehicle telemetry data acquisition advantageously takes into account a predetermined period (e.g., 3 months), which preferably includes data of the measurement of the IRI value.

[0031] According to an aspect of the invention, in a preparation step 1, an IRI value associated with a road is matched to a corresponding first road profile, profile r and the first road profile, profile r, is determined according to standard procedures. For example, the first road profile, profile ris determined by interpolating previously measured values ​​of vertical acceleration determined according to certain conditions (e.g., low speed and a predefined acquisition frequency) specific to a given vehicle type / model.

[0032] According to a further aspect of the invention, a GPS is used to position the vehicle on the road where measurements are taken in either the preparation step 1 or the IRI estimation step 10.

[0033] Referring to FIG. 1, in a preparation step 1, a second vehicle vertical acceleration value Az 出力 - The step of determining f(c, k) (block 5) is - Value C of the coefficient of damping and stiffness of vehicle tires t , K t When the input is made by d A fourth vehicle vertical acceleration value Az 出力 and, - the vehicle vertical acceleration function f(c, k) depending on the parameters c and k, This includes determining:

[0034] In particular, the parameters c and k are the vehicle suspension damping and stiffness coefficient values ​​of one or more suspensions (not shown) of the vehicle considered. Thus, the second road profile (which is a value of the vehicle vertical acceleration), profile d The output of depends directly on the values ​​of the vehicle suspension damping and stiffness coefficients c, k of the suspension or suspensions of the considered vehicle.

[0035] Referring to FIG. 3, vehicle suspension damping and stiffness coefficient values ​​C of one or more suspensions of one or more vehicles are s , K s The step of determining (block 6) is - Second road profile, profile d The suspension damping and stiffness coefficient values ​​c for the test vehicle of the vehicle suspension input to 0 , k0 About Az 出力 -f(c 0 , k 0 ) and a corresponding second vehicle vertical acceleration value Az 出力 - determining f(c, k) (block 21); - a second vehicle vertical acceleration value Az 出力 -f(c 0 , k 0 ) a second acceleration profile generated from the first vehicle vertical acceleration value Az 車両 and determining whether the first acceleration profile generated from the first acceleration profile (block 22) matches the first acceleration profile generated from the first acceleration profile (block 23). Includes.

[0036] Furthermore, values ​​of vehicle suspension damping and stiffness coefficients C of one or more suspensions of one or more vehicles s , K s The step of determining (block 6) is - a second vehicle vertical acceleration value Az 出力 -f(c 0 , k 0 ) a second acceleration profile generated from the first vehicle vertical acceleration value Az 車両 a test vehicle damping and stiffness coefficient value c of the suspension of the vehicle when the first acceleration profile matches a first acceleration profile generated from 0 , k 0 is the vehicle suspension damping and stiffness coefficient C s , K s (block 23), or - a second vehicle vertical acceleration value Az 出力 -f(c 0 , k 0 ) a second acceleration profile generated from the first vehicle vertical acceleration value Az 車両 if the first acceleration profile generated from 0 , k 0 Determining the new value of (block 24) Further includes:

[0037] Thus, in accordance with an aspect of the present invention, the steps of determining (block 21) and verifying (block 22) include determining the test vehicle damping and stiffness coefficient values ​​c of the vehicle's suspension. 0 , k 0 satisfies the requirements of the checking step (block 22), and therefore the vehicle suspension damping and stiffness coefficient C s , K s This is repeated until it can be defined as

[0038] At the end of the determining step (Block 6), vehicle suspension damping and stiffness coefficient values ​​C of one or more suspensions of one or more vehicles are obtained. s , K s is the second road profile, profile d is determined as the output of

[0039] FIG. 4 shows the first and second vehicle vertical acceleration values ​​Az 車両 , Az 出力 10A-f(c, k) (c, k) s , K s is equal to.

[0040] Further, referring to FIG. 5, in the preparation step 1, first and second vehicle vertical acceleration values ​​Az 車両 , Az 出力 - determining the first and second root mean square values ​​of f(c,k), respectively (block 7), - First road profile, profile r Based on the above, a first vehicle vertical acceleration value Az is calculated for a vehicle driven on a known road at a known different speed. 車両 Calculating a first root mean square value of (block 31); - Second road profile, profile d , vehicle suspension damping and stiffness coefficient value C s , K sBased on this, a second vehicle vertical acceleration value Az is calculated for a vehicle driven at the same known different speed on the same known road. 出力 - determining a second root mean square value of f(c, k) (block 32); - Below, Az 出力 -f(C s , K s ) the second vehicle vertical acceleration value Az 出力 - for a second root mean square value of f(c, k), a first vehicle vertical acceleration value Az 車両 3. Plot (block 33) the first root mean square value of the second road profile, profile d is the first road profile, profile r and to check whether the fit is sufficient to match the results of Includes.

[0041] In particular, the plotting step (block 33) involves plotting a second vehicle vertical acceleration value Az together with the known IRI value of the considered road. 出力 -f(C s , K s ) for the second RMSVA, the first vehicle vertical acceleration value Az 車両 FIG. 6 shows the second vehicle vertical acceleration value Az 出力 -f(C s , K s ) a first vehicle vertical acceleration value Az filtered at 1.5 Hz for a second RMSVA of 車両 6 shows the plot obtained through the plotting step (block 33) performed by plotting the first RMSVA of 1. As can be seen in FIG. 6, different speeds are taken into account.

[0042] Furthermore, in the preparation step 1, a known International Roughness Index value or a first road profile, profile r , the second vehicle vertical acceleration value Az 出力a second vehicle vertical acceleration value Az based on the second root mean square value of f(c, k), the second vehicle georeference data, and the second vehicle speed data; 出力 - determining one or more vehicle transfer functions mathematically related to the second root mean square value of f(c, k) and the International Roughness Index value at a given constant speed (Block 8) includes determining the IRI value and the second vehicle vertical acceleration value Az 出力 -f(C s , K s ) a second RMSVA of the vehicle transfer function, JPEG2024518322000002.jpg733 is determined. In this regard, FIG. 7 shows the results of the comparison of the different constant vehicle speeds. JPEG2024518322000003.jpg719 shows an example graph where IRI values ​​at different constant vehicle speeds are plotted and a second vehicle vertical acceleration value Az 出力 -f(C s , K s ) is plotted. In particular, the example transfer function shown in FIG. 7 is as follows: JPEG2024518322000004.jpg13108 During the ceremony, JPEG2024518322000005.jpg72 refers to vehicle speed.

[0043] 2, in the IRI estimation step 10 and for the third vehicle vertical acceleration value Az, the step of estimating an International Roughness Index value for a given road or road segment based on one or more vehicle transfer functions determined in the preparatory step 1, as well as the third root-mean-square value of the third vehicle vertical acceleration value Az and the associated third vehicle georeference data and third vehicle speed data (block 13) is performed by performing an inverse calculation. Indeed, once at least one transfer function has been determined in the preparatory step 1, the third root-mean-square value determined from the third vehicle vertical acceleration value Az and the driving speed of the given vehicle on a typical road may be calculated based on the third root-mean-square value of the third vehicle vertical acceleration value Az and the associated third vehicle georeference data and third vehicle speed data. JPEG2024518322000006.jpg72 is known and it is possible to calculate an estimated IRI value.

[0044] The present invention also relates to a system designed to carry out the above-mentioned IRI estimation method. In this regard, Fig. 8 shows, by means of a block diagram, a schematic functional structure of an IRI estimation system 50 according to a preferred embodiment of the present invention.

[0045] In particular, the IRI estimation system 50: - installed on board a motor vehicle equipped with an internal combustion engine or a hybrid / electric motor vehicle (not shown in FIG. 8), such as a passenger car or a bus or a truck or a motorbike, - coupled to a vehicle bus 60 (based on a standard Controller Area Network, CAN, bus) of the motor vehicle; - configured to obtain vehicle vertical acceleration and vehicle georeference and speed data from said vehicle bus 60; The acquisition device 51 is provided.

[0046] According to a preferred embodiment of the present invention, each acquisition device 51: - carrying out a preparatory step 1 and obtaining from the vehicle bus 60 of each of the motor vehicles first and second vehicle vertical acceleration values ​​Az 車両 , Az 出力 - each vehicle used to obtain f(c, k) and the first and second vehicle georeferences and the first and second vehicle speed data; - obtaining a third vehicle vertical acceleration value Az and third vehicle georeference and speed data from a respective vehicle bus 60 of the given vehicle, for each given vehicle involved in the IRI estimation step 10; It can be installed in a vehicle.

[0047] Additionally, the IRI estimation system 50 is connected, by wire or wirelessly, to an acquisition device 51 from which the first, second, and third vehicle vertical acceleration values ​​Az 車両 , Az 出力- receiving f(c,k), Az and first, second and third vehicle georeferences and first, second and third vehicle speed data; - the first and second root mean square values ​​Az 車両 , Az 出力 - Calculate f(c, k) to determine the vehicle transfer function (block 8); and - Calculate the third root mean square value to estimate the IRI value (block 13) The device further comprises a processing means 52 programmed to:

[0048] 9 and 10 show diagrammatically further preferred embodiments for implementing the processing means 52 of the system 50 of FIG.

[0049] In particular, with reference to FIG. 9 , in a first preferred embodiment (generally designated 70), the processing means 52 is implemented / performed using a cloud computing system 72 that is wirelessly and remotely connected to the acquisition device 51 (e.g. via one or more cellular technologies such as GSM, GPRS, EDGE, HSPA, UMTS, LTE, LTE Advanced, 5G, etc.) and that is conveniently used to perform both the preparation step 1 and the IRI estimation step 10.

[0050] Alternatively, referring to FIG. 10, in a second preferred embodiment (generally designated 100), the processing means 52 is implemented / performed using an (automotive) Electronic Control Unit (ECU) 102 installed on-board the motor vehicle 110, where said ECU 102 may conveniently be an ECU specifically dedicated to IRI estimation, or an ECU dedicated to several tasks including IRI estimation as well.

[0051] Preferably, the cloud computing system 72 is used to perform the preparation step 1, while the ECU 102 is used to perform the IRI estimation step 10. In particular, a respective ECU 102 may be conveniently installed on-board each given motor vehicle 110 involved in the IRI estimation step 10 to acquire second vehicle vertical acceleration values ​​and second vehicle georeference and speed data from a respective acquisition device 51.

[0052] From the above, the technical advantages and innovative features of the present invention will be immediately apparent to those skilled in the art.

[0053] In particular, the method makes it possible to measure preliminary IRI values ​​on a driven road using vehicle vertical acceleration values ​​at a given constant speed more frequently than is typically used in road measurement procedures.

[0054] Additionally, the method has a wider and more frequent measurement network that allows road operators to prioritize more accurate measurements on specific road segments.

[0055] Additionally, the method allows for faster and easier quantification of road pavement roughness, particularly estimation of IRI, which is easier and can be performed more frequently than traditional IRI measurements.

[0056] Finally, it will be apparent that numerous modifications and variations may be made to the present invention which are included within the scope of the invention as defined in the appended claims.

Claims

1. A method for estimating an International Roughness Index (IRI) of a road or road segment, comprising a preparation step (1) and an International Roughness Index estimation step (10), The preparation step (1) includes: - the value of the vehicle tire damping and stiffness coefficient of one or more tires of one or more motor vehicles (C ｔ , K ｔ (2) collecting a) a known International Roughness Index value or a known first road profile (profile ｒ a first vehicle vertical acceleration value (Az) measured on one or more vehicles driven at one or more given constant speeds along one or more roads or road segments to which the vehicle vertical acceleration value (Az) is associated; 車両 )and, b) the measured first vertical acceleration value (Az 車両 ) a first vehicle georeference data associated with the vehicle; c) the measured first vertical acceleration value (Az 車両 a first vehicle speed data indicating a given constant speed associated with the vehicle speed sensor; (3) collecting - the value of said vehicle tire damping and stiffness coefficient (C ｔ , K ｔ ), the first vehicle georeference data, the first vehicle speed data, and the first vehicle vertical acceleration value (Az 車両 ) based on the second road profile (profile ｄ ) (4) Including, The preparation step (1) includes: - said second road profile (profile ｄ ) based on the second vehicle vertical acceleration value (Az 出力 -f(c, k)), the second vertical acceleration value (Az 出力 - second vehicle georeference data of f(c,k)), said measured first vertical acceleration value (Az 出力 - second vehicle speed data indicative of the given constant speed associated with the vehicle tire speed (c, k), and values ​​of tire damping and stiffness coefficients for the vehicle tire (C ｔ , K ｔ ) (5); and - vehicle suspension damping and stiffness coefficient values ​​(C ｓ , K ｓ ) (6); and said first and second vehicle vertical acceleration values ​​(Az 車両 , Az 出力 - determining first and second root mean square values ​​of f(c,k) respectively (7); - said known International Roughness Index value or said first road profile (profile ｒ ), the second vehicle vertical acceleration value (Az 出力 - determining the second vehicle vertical acceleration value (Az 出力 - determining one or more vehicle transfer functions that are mathematically related to the second root mean square value of f(c,k) and the International Roughness Index value at the given constant speed (8); Further comprising: The international roughness index estimation step (10) comprises: - obtaining (11) a third vehicle vertical acceleration value (Az) measured for a given vehicle driven on a given road or road segment at a driving speed, third vehicle georeference data associated with said third vehicle vertical acceleration value (Az) and third vehicle speed data indicative of said given driving speed of said vehicle; - calculating (12) a third root mean square value of said third vehicle vertical acceleration value (Az); - estimating (13) an International Roughness Index value for said given road or road segment based on the one or more vehicle transfer functions determined in said preparatory step (1) and on said third root mean square value of said third vehicle vertical acceleration value (Az) and said associated third vehicle georeference data and said third vehicle speed data; A method comprising:

2. The first vehicle vertical acceleration value (Az 車両 ), the first vehicle georeference data, and the first vehicle speed data are referenced to a known International Roughness Index value or the first road profile (profile ｒ collected in steps a), b) and c) for one or more motor vehicles of one and the same given vehicle type and / or one and the same given vehicle model driven at one or more given constant speeds along one or more roads or road segments to which the road segment is associated, The second road profile (profile ｄ 2. The method of estimating the International Roughness Index as recited in claim 1, wherein:

3. The first vehicle vertical acceleration value (Az 車両 ), the first vehicle georeference data and the first vehicle speed data are collected in steps a), b) and c) for each of one or more motor vehicles of different given vehicle types and / or different given vehicle models; The second road profile (profile ｄ 2. The method of estimating the International Roughness Index as recited in claim 1, wherein:

4. 3. The method of estimating an International Roughness Index as claimed in claim 2, wherein the International Roughness Index value is estimated (13) by using a vehicle transfer function specific to the given motor vehicle type / model determined in the preparing step (1).

5. the vehicle suspension damping and stiffness coefficient values ​​(C ｓ , K ｓ The step (6) of determining - said second road profile (profile ｄ ) the test vehicle suspension damping and stiffness coefficient values ​​(c ０ , k ０ ), the corresponding second vehicle vertical acceleration value (Az 出力 -f(c ０ , k ０ )) (21); and - the second vehicle vertical acceleration value (Az 出力 -f(c ０ , k ０ The second acceleration profile generated from the first vehicle vertical acceleration value (Az 車両 ) to determine whether the first acceleration profile matches a first acceleration profile generated from the first acceleration profile (22); Including, the vehicle suspension damping and stiffness coefficient values ​​(C ｓ , K ｓ The step (6) of determining - the second vehicle vertical acceleration value (Az 出力 -f(c ０ , k ０ The second acceleration profile generated from the first vehicle vertical acceleration value (Az 車両 ) the test vehicle damping and stiffness coefficient values ​​(c ０ , k ０ ) is the vehicle suspension damping and stiffness coefficient (C ｓ , K ｓ ) (23), or - the second vehicle vertical acceleration value (Az 出力 -f(c ０ , k ０ The second acceleration profile generated from the first vehicle vertical acceleration value (Az 車両 ) does not match the first acceleration profile generated from the test vehicle suspension damping and stiffness coefficient values ​​(c ０ , k ０ ) (24) determining a new value of The method for estimating the International Roughness Index as claimed in claim 1 , further comprising:

6. The first and second vehicle vertical acceleration values ​​(Az 車両 , Az 出力 - the step (7) of determining the first and second root mean square values ​​of f(c,k) respectively, said first road profile (profile ｒ ), for a vehicle driven on a known road at different known speeds, the first vehicle vertical acceleration value (Az 車両 ) (31); and - said second road profile (profile ｄ ), the vehicle suspension damping and stiffness coefficient value (C ｓ , K ｓ ), for a vehicle driven at the same known different speed on the same known road, the second vehicle vertical acceleration value (Az 出力 - determining (32) a second root mean square value of f(c,k)); - the second vehicle vertical acceleration value (Az 出力 -f(C ｓ , K ｓ )) the first vehicle vertical acceleration value (Az 車両 ) to plot (33) the first root mean square value of the second road profile (profile ｄ ) is the first road profile (profile ｒ ) to see if it fits well enough to match the results The method for estimating the International Roughness Index according to claim 1 , comprising:

7. A system (50, 70, 100) for estimating the International Roughness Index, designed to perform the method for estimating the International Roughness Index according to claim 1.

8. for each vehicle (90, 110) used to carry out said preparatory step (1) of the method for estimating the International Roughness Index, - mounted on said motor vehicle (90, 110), - coupled to a vehicle bus (60) of each of said vehicles (90, 110), - configured to obtain vehicle vertical acceleration and vehicle georeference and speed data from each of said vehicle buses (60); Each first acquisition device (51); for each given vehicle (90, 110) involved in the international roughness index estimation step (10) of the method for estimating an international roughness index, - installed on board said given motor vehicle (90, 110), - coupled to the respective vehicle bus (60) of said given motor vehicle (90, 110); configured to obtain, from each of said vehicle buses (60), said third vehicle vertical acceleration value (Az) as well as said third vehicle georeference and said third speed data; a respective second acquisition device (51); - connected to said first and second acquisition devices (51) and for receiving said first, second and third vehicle vertical acceleration values ​​(Az 車両 , Az 出力 - f(c,k), Az), receiving the first, second and third vehicle georeferences and the first, second and third vehicle speed data; - calculating said first and second root mean square values ​​to determine said vehicle transfer function; - calculating said third root mean square value to estimate said International Roughness Index value; It is configured as follows: Processing means (52); The system for estimating the International Roughness Index according to claim 7, comprising:

9. The system for estimating an International Roughness Index as claimed in claim 8, wherein the processing means (52) comprises a cloud computing system (72) remotely connected to the acquisition device (51) and used to perform both the preparation step (1) and the International Roughness Index estimation step (10).

10. The processing means (52) a cloud computing system (72) remotely connected to said first acquisition device (51) and configured to perform said preparation step (10); - for each given motor vehicle (90, 110) involved in said international roughness index estimation step (10), a respective electronic control unit (102) installed on-board said given motor vehicle (90, 110), connected to said respective second acquisition device (51) and configured to execute said international roughness index estimation step (10); The system for estimating the International Roughness Index according to claim 8 , comprising:

11. A cloud computing system (72) configured to perform both the preparation step (1) and the international roughness index estimation step (10) of the method for estimating an international roughness index according to any one of claims 1 to 6, or only the preparation step (1) thereof.

12. An electronic control unit (102) designed to be installed on board a motor vehicle (90, 110) and configured to perform the international roughness index estimation step (10) of the method for estimating an international roughness index according to any one of claims 1 to 6.

13. - loadable into processing means (52, 72, 102); - when loaded, said processing means (52, 72, 102) are configured to execute the preparation step (1) and / or the international roughness index estimation step (10) of the method for estimating an international roughness index according to any one of claims 1 to 6. A computer program product that includes one or more software and / or firmware code portions.

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