Longitudinal Road Profile Research Articles

Physics-informed neural networks to advance pavement engineering and management

Physics-informed neural networks (PINN) are machine learning (ML) algorithms that can bridge the gap between our understanding of physical phenomena and the corresponding empirical observations. This paper discusses applications of physics-integrated ML to advance pavement engineering. To demonstrate an example, a PINN model was pretrained to approximate the simulation of vehicles’ suspension responses to longitudinal road profiles. The parameters of the outer layers were finetuned to adapt model output to the standard International Roughness Index (IRI), while keeping the pretrained inner layers to preserve the embedded physical knowledge of the suspension behaviour. The PINN model showed low bias and standard error in predicting IRI values on training, test, and an independent dataset from an autonomous vehicle study by the Ford Motor Company. This approach to reconcile and supplement infrequent survey data with spatiotemporally continuous data (from connected vehicles) can enhance data-driven practices for pavement design, maintenance and asset management.

АНАЛИЗ ВЛИЯНИЯ УСЛОВИЙ РАБОТЫ ЛЕСОВОЗНЫХ АВТОПОЕЗДОВ НА НАДЕЖНОСТЬ И СВОЕВРЕМЕННОСТЬ ИХ ТЕХНИЧЕСКОГО ОБСЛУЖИВАНИЯ

The description of the road and natural-climatic conditions for the operation of timber-carrying road trains is given. The main features of logging roads, which are characterized by insufficient infrastructure, are considered. The analysis of the negative consequences of the movement of logging road trains along such logging roads in various natural and climatic conditions is carried out. The dependences of the change in the speed of movement and fuel consumption of a logging road train on the nature of the longitudinal profile of the logging road, the performance of the road train on the distance of hauling timber are given. The patterns of change in the speed of movement and the travel fuel consumption of a logging road train depending on its workload and movement along logging roads with different slope values, as well as road roughness parameters, are analyzed. The influence of road conditions of operation of timber road trains on the reliability of their main units and systems is described. The features of maintenance of timber road trains involved in the process of hauling timber are analyzed. The dependences of the change in the flow of spare parts consumption for maintaining the working condition of cars during the year are considered. The patterns of change with increasing mileage of the KAMAZ-53105 vehicle in the mean time between failures and the coefficient of technical readiness are shown.

Influence of undefined modes of movement on instantaneous redistribution of normal reactions of quarry dump truck tires

Reducing the costs of rock transportation in mining is one of the most important tasks. One of the reserves for solving this issue is a more complete use of the service life of quarry dump trucks tires, since their operation takes place in heavy mining and climatic conditions and this significantly reduces the life of tires. The life of tires depends on many factors: speed of movement, compliance with the recommended air pressure in the tire, ambient air temperature, but the main thing is the change in the normal load on the wheel, which depends on the redistribution of the quarry dump truck weight in case of non-linear movement and on the longitudinal profile of the quarry road. In real conditions, the quarry dump truck moves unevenly due to the complexity of the road - either braking or acceleration occur. This article allows you to evaluate the impact of non-linear modes of quarry dump truck movement on the instant redistribution of normal tire reactions and take into account peak loads on wheels during acceleration and braking in the regular cycle. This will allow you to control the load on the tires directly by cargo amount in the quarry dump truck and thereby increase the life of the tires and their reliability, as well as reduce the cost of transporting the rock mass in real operating conditions.

Slope Optimization (or “Sloop”): Customized Optimization for Road Longitudinal Profile Eco-Design

Current transportation systems contributed to one quarter to the Greenhouse Gases (GhG) emissions and the mobility demand increases continuously. The transportation infrastructure design has to be optimized to mitigate these emissions. The methodology “Sloop” (acronym for Slope Optimization) has recently been set up to optimize the longitudinal road profile with respect to a Global Warming Potential (GWP) criterion calculated for both the construction and operational phases while incorporating accurate vehicle models. This paper proposes a customized optimization strategy that significantly improves the Sloop methodology. From an initial longitudinal profile generated by road designers, our algorithm identifies the optimized profile in terms of GWP. This optimization step is complex due to the large number of degrees of freedom, along with various constraints to obtaining a feasible solution and the computational cost of the operational phase assessment. The most stringent constraint entails connecting the profile with the existing road (i.e., a constraint on the final profile altitude). We have developed a specific algorithm based on the Sequential Quadratic Programming (SQP) method; this algorithm takes into account the quasi-quadratic nature of the constraint on the final altitude. In a real case study, our algorithm outputs a profile whose GWP assessment saves 4% compared to the GWP assessment of the initial profile. The benefit of our specific protocol for treating the final altitude constraint is demonstrated in this example. By means of this new efficient and open-box algorithm, profile evolution at each iteration is analyzed to determine the most sensitive degrees of freedom, and the sensitivity of the optimization with respect to the main construction parameters and traffic assumptions are conducted. The results are consistent and stable.

Comparison of road inequality values using roughometer III and roadroid applications

Roads are essential in the development of an area, where driving safety and comfort are a measure of road construction. We can check road construction by getting an IRI value on a road segment. IRI (International Roughness Index) is the roughness index that most commonly obtained from measured longitudinal road profiles. Roughometer III and Roadroid applications are the tolls to collect IRI data. Roughometer III has more precision than Roadroid, but the Roughometer III is more expensive and more complex than Roadroid. This study tries to make a comparison of IRI values and their correlation between the Roughometer III and Roadroid. The results show that the comparison of IRI Roughometer III values and Roadroid Applications is slightly different. The linear correlation analysis of IRI values on Roughometer III and eIRI values on Roadroid is IRI = 0.8999eIRI + 0.5786 with a correlation level of = 0.8391.

Statistical characteristics of sources of vehicle kinematic excitation

The longitudinal and transverse road profiles represent the functions of a random variable from a mathematical point of view. It is appropriate to use methods of probability theory and mathematical statistics for their description. The unevenness of the runway surface is the main source of the vehicle's kinematic excitation. This paper describes the statistical properties of the mapped road profiles. It shows a way of categorizing road surface quality based on the power spectral density of unevenness. The interrelationships between the individual points of the profile and the profiles with one another are evaluated by correlation functions.

Longitudinal profile optimization for roads within an eco-design framework

This paper proposes a methodology to optimize the longitudinal profile of roads according to either an energy consumption or Global Warming Potential (GWP) criterion calculated for both construction and operation phases. For the construction phase assessment, this methodology is based on a earthworks model that computes the geometric differences between the natural terrain and the longitudinal road profile and moreover uses environmental data validated with real experiments. The operation phase is assessed by simulating traffic over a ten-years period. Traffic simulations are based on vehicle dynamic models, also validated with real experiments. The optimization problem is set up in a finite dimensional optimization. A case study illustrates this methodology. By taking into account actual traffic measurements, the optimized profile decreases by 6% the total primary energy consumption and by 8% the GWP.

IMU-Based Virtual Road Profile Sensor for Vehicle Localization

A road profile can be a good reference feature for vehicle localization when a Global Positioning System signal is unavailable. However, cost effective and compact devices measuring road profiles are not available for production vehicles. This paper presents a longitudinal road profile estimation method as a virtual sensor for vehicle localization without using bulky and expensive sensor systems. An inertial measurement unit installed in the vehicle provides filtered signals of the vehicle’s responses to the longitudinal road profile. A disturbance observer was designed to extract the characteristic features of the road profile from the signals measured by the inertial measurement unit. Design synthesis based on a Kalman filter was used for the observer design. A nonlinear damper is explicitly considered to improve the estimation accuracy. Virtual measurement signals are introduced for observability. The suggested methodology estimates the road profile that is sufficiently accurate for localization. Based on the estimated longitudinal road profile, we generated spectrogram plots as the features for localization. The localization is realized by matching the spectrogram plot with pre-indexed plots. The localization using the estimated road profile shows a few meters accuracy, suggesting a possible road profile estimation method as an alternative sensor for vehicle localization.

Simulated Road Profiles According to ISO 8608 in Vibration Analysis

Abstract Nowadays, synthetic longitudinal road profiles based on an ISO 8608 road classification are used for simulation purposes to solve various tasks in vibration analysis of mechanical and civil structures and road-vehicle-driver interaction system. Standard ISO 8608 specifies road classification of longitudinal road profiles based on vertical displacement power spectral density (PSD). PSD represented on logarithmic scales is characterized by two parameters of a straight line, an unevenness index and waviness. The aim of this study was to compare spectrum parameters of real roads with ISO 8608 road classes used in scientific papers. Road classes that were used in a sample of 27 current scientific papers were analyzed. Results often indicated marked differences among road classes used for simulation purposes in comparison to the spectrum properties of real roads. For simulation purposes, road Class A may be recommended as representative of typical good or average quality road (motorway, expressway, and first class road). Classes B and C may be appropriate to simulate low-quality paved surfaces (2nd and 3rd class roads or local highways).

The Priority of Road Rehabilitation in Karanganyar Regency Using IRI Estimation from Roadroid

The IRI (International Roughness Index) is a road roughness index commonly obtained from measured longitudinal road profiles. This is one of the functional performance a surface of road pavement. Therefore, needs to be done evaluation and monitoring periodically to getting priority of road rehabilitation right on target. The IRI standard has commonly been used worldwide for evaluating road system. The Roadroid is an application to measure road quality with a website to view road quality. It is designed for Android smartphones, so we can easily measure and monitor the road and also use the camera for GPS-tagged photo. By using the built-in vibration sensor in smartphones, it is possible to collect IRI value which can be an indicator road conditions. This study attempts to explain the priority of road rehabilitation in Karanganyar Regency. The location of the study focused on a collector street (primary, secondary and locally road). The result of IRI estimation will be combined with other aspects that influences; land use, policy, the connectivity of road and traffic average daily. Based on IRI estimation using Roadroid, the road conditions in Karanganyar Regency can be described 59,60% were good (IRI<4,5); 21,30% fair (4,5<IRI<8), 11,40% bad (8<IRI<12), and 7,70% poor (IRI>12).

Evaluation of the methodologies used to generate random pavement profiles based on the power spectral density: An approach based on the International Roughness Index

The pavement roughness is the main variable that produces the vertical excitation in vehicles. Pavement profiles are the main determinant of (i) discomfort perception on users and (ii) dynamic loads generated at the tire-pavement interface, hence its evaluation constitutes an essential step on a Pavement Management System. The present document evaluates two specific techniques used to simulate pavement profiles; these are the shaping filter and the sinusoidal approach, both based on the Power Spectral Density. Pavement roughness was evaluated using the International Roughness Index (IRI), which represents the most used index to characterize longitudinal road profiles. Appropriate parameters were defined in the simulation process to obtain pavement profiles with specific ranges of IRI values using both simulation techniques. The results suggest that using a sinusoidal approach one can generate random profiles with IRI values that are representative of different road types, therefore, one could generate a profile for a paved or an unpaved road, representing all the proposed categories defined by ISO 8608 standard. On the other hand, to obtain similar results using the shaping filter approximation a modification in the simulation parameters is necessary. The new proposed values allow one to generate pavement profiles with high levels of roughness, covering a wider range of surface types. Finally, the results of the current investigation could be used to further improve our understanding on the effect of pavement roughness on tire pavement interaction. The evaluated methodologies could be used to generate random profiles with specific levels of roughness to assess its effect on dynamic loads generated at the tire-pavement interface and user’s perception of road condition.

Sensitivity of road unevenness indicators to short wavelength distresses in Portland cement concrete surfaces

This paper examined the sensitivity of 20 road unevenness indicators (RUIs) for local discontinuities (various distresses, joints, joint and surface defects, cracks, spalls, other road features, humps, dips, etc.) of a maximum length of 20 cm in Portland cement concrete pavements. Approximately, 5500 road records totalling 530 km from the Long-Term Pavement Performance programme were processed. Raw profiles were separated into random and distress components using a median filtering method. The median filter was set to identify distress of a maximum length of 20 cm and with a minimal height of 3 mm. Over 26,000 distresses and their dimensions were identified. Raw longitudinal road profiles were compared with the separated pure random components. The most sensitive indicators of distresses were road elevation spectrum parameters in whole- and short-wave bands, the Profile Index and the road elevation root mean square (RMS) value in the short-wave band. Negligible sensitivity was observed for the International Roughness Index, road elevation RMS values and spectrum parameters in long- and medium-wave bands. The influence of road data pre-processing on the results was estimated.

Sensitivity of International Roughness Index to Distresses of Cement Concrete Road Surfaces

The paper examined the sensitivity of International Roughness Index (IRI) to the local discontinuities (various distresses, joints, joint and surface defects, other road features, etc.) of the cement concrete (CC) pavements. About 5 300 road records of total length 470 km from Long Term Pavement Performance (LTPP) program were processed. The raw profiles were separated into a random part and a distress part using the median filtering method. The median filter order was set to identify distresses of variable maximum width from 20 to 40 cm, and minimal height, 3 mm. About 26 000 distresses were separated and their dimensions were identified. The raw longitudinal road profiles were compared with the separated pure random parts. The mean relative increase in IRI caused by distresses was 3.3 % for maximum distress width 20 cm, 6.6 % (30 cm), and 10.7 % (40 cm).

Influence of tyre–road contact model on vehicle vibration response

The influence of the tyre–road contact model on the simulated vertical vibration response was analysed. Three contact models were compared: tyre–road point contact model, moving averaged profile and tyre-enveloping model. In total, 1600 real asphalt concrete and Portland cement concrete longitudinal road profiles were processed. The linear planar model of automobile with 12 degrees of freedom (DOF) was used. Five vibration responses as the measures of ride comfort, ride safety and dynamic load of cargo were investigated. The results were calculated as a function of vibration response, vehicle velocity, road quality and road surface type. The marked differences in the dynamic tyre forces and the negligible differences in the ride comfort quantities were observed among the tyre–road contact models. The seat acceleration response for three contact models and 331 DOF multibody model of the truck semi-trailer was compared with the measured response for a known profile of test section.

Sensitivity of Road Unevenness Indicators to Distresses of Composite Pavements

The paper examined the sensitivity of nineteen road unevenness indicators (RUI) to the distresses (reflection cracks, transverse cracks) of the composite pavements. The simulated longitudinal road profiles with superimposed distresses were compared with the pure random part of profiles to estimate the difference in roughness. The influence of distress width, depth, density, and road data pre-processing (moving average base length and sampling interval) was estimated. Analysis of variance was provided to detect the significance of differences in estimated RUIs for distressed and random profiles. The most sensitive indicators to the presence of the reflection cracks were the root mean square (RMS) value in the short wave band, the road elevation spectrum parameters in the whole and short wave bands. A weak sensitivity was observed for the International Roughness Index (IRI), Ride Number (RN), Profilograph Index (PrI) or the road elevation RMS values in the long and medium wave bands.

Current approaches to quantify the longitudinal road roughness

Paper summarised the proposals of fourteen new alternative indexes intended for road roughness evaluation of longitudinal road profile, which have been introduced in the last decade approximately. The main advantages of proposed indexes are: (1) effort to reflect the most of ride quality aspects such as ride comfort, ride safety and dynamic load of road or cargo; (2) using the in situ measurements of vibration response or subjective perception of vibration; (3) effort to reflect the vehicle responses such as roll and pitch vibration, or longitudinal and lateral vibration; (4) effort to detect the critical parts of road in a spatial domain; and (5) effort to reflect a vehicle velocity. The main limitations of proposed indexes are: (1) many proposals are only alternative to the international roughness index (IRI) or are based on the IRI procedure; (2) a simple one-dimensional vehicle model is often used with the constant parameters and velocity; and (3) orientation to one vibration response category as ride comfort.

A multibody dynamics model to assess the impact of road unevenness on the efficiency of a semitrailer truck

An open source multibody model of a semi-trailer truck with 331 degrees of freedom was built and within it a dynamic tyre model has been implemented. The truck model was calibrated and validated by an on-road experimental campaign of coastdown tests. The signal from a photodetector and ten accelerometers, the weight distribution, meteorological data, and the longitudinal profile have been collected. The purpose of the model is to obtain the relationships between the longitudinal road profile and fuel consumption, vehicle wear, passenger health, and safety. A subsequent study demonstrated the capacity of the model to fulfil its purpose.

An overview of various new road profile quality evaluation criteria: part 1

A multibody tractor–trailer model specialised in measuring the impact of road surface quality on the efficiency of transport was developed. It was calibrated and validated using a coastdown tests experimental campaign. The model was then used within an extensive profile study that linked specific profiles to their impact on energy consumption, vehicle wear, driver and passenger health, and safety. Two hundred and seventy 1 km long profiles were tested with the multibody vehicle travelling at 100 km/h. It allowed to identify trends in the relationships between various profile rating criteria and the impacts aforementioned. The criteria consist of 19 indices observed on a quarter car model operating on longitudinal road profiles. They yield accurate predictions of profile impacts. For the operating conditions considered, the long wavelengths have a strong effect on health, medium wavelengths on safety and short to medium wavelengths on energy consumption.

Road profile measurement using the two degrees of freedom response-type mechanism

This paper deals with the two degrees of freedom response-type mechanism (2 DOF RTM) designed at Iran University Science and Technology. The applications of the 2 DOF RTM are to measure the longitudinal road profile and assess the vehicle suspension system. When the 2 DOF RTM is connected to a vehicle, it is able to measure the longitudinal road profile and it is capable of assessing the vehicle suspension system while it is perched upon the exciting device. The most important part of the 2 DOF RTM is its hub planned for decreasing the vehicle movement effects on the measurement. Moreover, this paper develops a novel procedure in order to convert the measured profile from the variable speed to the constant speed. To examine the 2 DOF RTM, a profile of a road is measured by the mechanism in the time-domain, and then the highly significant roughness indices such as power spectral density (PSD) of the road unevenness, international roughness index (IRI) and present serviceability index (PSI) are estimated using the measured profile.

Piecewise Parabolic Approximation of Plane Curves with Restrictions in Computer-Aided Design of Road Routes

Approximation problems of plane curves, which are set as a sequence of points arise in computer-aided design of roads. Approximating curve consists of the elements: straight-line and parabolas segments. The parameters of these elements are constrained. Moreover, the number of elements is unknown. This article deals with the problem of per-element approximation, in which the elements must meet to the restrictions of special kind. This problem arises in computer-aided design of the longitudinal profile of road. The problem is solved by dynamic programming.