In many countries, work is being conducted to introduce Weigh-In-Motion (WIM) systems intended for continuous and automatic control of gross vehicle weight. Such systems are also called WIM systems ...for direct enforcement (e-WIM). The achievement of introducing e-WIM systems is conditional on ensuring constant, known, and high-accuracy dynamic weighing of vehicles. WIM systems weigh moving vehicles, and on this basis, they estimate static parameters, i.e., static axle load and gross vehicle weight. The design and principle of operation of WIM systems result in their high sensitivity to many disturbing factors, including climatic factors. As a result, weighing accuracy fluctuates during system operation, even in the short term. The article presents practical aspects related to the identification of factors disturbing measurement in WIM systems as well as methods of controlling, improving and stabilizing the accuracy of weighing results. Achieving constant high accuracy in weighing vehicles in WIM systems is a prerequisite for their use in the direct enforcement mode. The research results presented in this paper are a step towards this goal.
In this paper, we present the results of a comparison of two estimators of the gross vehicle weight (GVW) and the static load of individual axles of vehicles. The estimators were used to process ...measurement data derived from Multi-Sensor Weigh-In-Motion systems (MS-WIM). The term estimator is understood as an algorithm according to which the dynamic axle load measurement results are processed in order to determine the static load. The result obtained is called static load estimate. As a measure of measurement uncertainty, we adopted the standard deviation of the static load estimate. The mean value and the maximum likelihood estimators were compared. Studies were conducted using simulation methods based on synthetic data and experimental data obtained from a WIM system equipped with 16 lines of polymer axle load sensors. We have shown a substantially lower uncertainty of estimates determined using the maximum likelihood estimator. The results obtained have considerable practical significance, particularly during long-term usage of multi-sensor WIM systems.
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•An electro mechanic (EM) model for WIM sensor considering pavement mechanic response.•Laboratory and pavement mechanical approaches to obtain the EM model coefficients.•Pavement ...elasticity and viscoelasticity proprieties to deliver the EM response.•The EM model calculated show very close similarity with real WIM sensor response.
This article aims at modeling the WIM sensor electrical behavior to provide a better understanding of the mechanical and electrical proprieties of piezoelectric sensors. The model is considered in the frequency domain, supposing any sinusoidal solicitation with constant frequency or any other type of solicitation. Tests, having real WIM sensors placed on the pavement of a test track at IFSTTAR/Nantes was used to verify the nature of the electro-mechanical (EM) behavior of the real sensors over punching, flexural and extension effects. Also, two different pavement numerical simulations deliver the mechanical response using linear elasticity and viscoelastic proprieties. The output of these two simulations are compared with two WIM signals obtained at same load and speed at two different temperature conditions.
•LTPP WIM data were used to study the effect of static and dynamic weight errors on WIM system performance.•The increased static weight errors can result in significant variation in the Gross Vehicle ...Weight errors.•The static weight errors are more critical for the WIM sites marginally passing the desired ASTM accuracy class.•The quantification of static weight errors can help highway agencies to accurately classify the WIM sites.
Weigh-in-Motion (WIM) systems require calibration to account for site conditions and regular calibrations (once or twice a year) to yield accurate and consistent loading data. Generally, the WIM system calibration compares the WIM weights with the reference static weights. However, the ground truth (static weights) accuracy may not be known and is uncertain. WIM protocols (ASTM 1318-09 and COST-323) specify the static error thresholds. Therefore, it is crucial to consider the errors induced due to static weighing procedures during the WIM equipment calibration and pre-validation. This paper uses the long-term pavement performance (LTPP) high-quality WIM data to study the effect of static weight measurement errors on the performance of the WIM system. The data analyses address two key concerns (a) modeling gross vehicle weight (GVW) errors while accounting for errors in the static and WIM weights, and (2) quantifying the effect of static truck weight errors for a variety of WIM sites with varying performance levels. The results show that the static weight errors are more critical for the WIM sites marginally meeting the desired ASTM 1318-09 accuracy class. A 2% static error may not change the overall performance of a WIM site (ASTM accuracy class based on tolerance limits), especially the sites with negligible bias or significantly higher bias. However, the ASTM accuracy class can change from higher to lower for WIM sites with intermediate bias (3 to 7%), even with a 1% increase in static weight errors.
The impacts of human-induced climate change are manifested through losses and damages incurred due to the increasing frequency and intensity of climatic disasters all over the world. Low-income ...countries who have contributed the least in causing climate change, and have low financial
capability, are the worst victims of this. However, since the inception of the international climate regime under the UN Framework Convention on Climate Change (UNFCCC), loss and damage has been a politically charged issue. It took about two decades of pushing by the vulnerable developing
countries for the agenda to formally anchor in the climate negotiations text. This was further solidified through establishment of the Warsaw International Mechanism (WIM) and inclusion of stand-alone Article 8 on loss and damage in the Paris Agreement. Its institutionalisation has only done
the groundwork of addressing loss and damage however - the key issue of finance for loss and damage and other matters has remained largely unresolved to date - particularly since Article 8 does not have any provision for finance. This has been due to the climate change-causing wealthy
developed nations' utter disregard for their formal obligations in the climate regime as well as their moral obligation. In this article, we tease out the central controversies that underpin the intractability of this agenda at the negotiations of the UNFCCC. We begin by giving a walk-through
of the concept and history of loss and damage in the climate regime. Then we present a brief account of losses and damages occurring in the face of rising temperature, and highlight the key issues of contention, focusing on the more recent developments. Finally, we conclude by suggesting some
way forward for the twenty-sixth session of the Conference of the Parties to the UNFCCC (COP26) taking place in Glasgow, UK in November 2021.
Bridge weigh in motion (B-WIM) uses accurate sensing systems to transform an existing bridge into a mechanism to determine actual traffic loading. This information on traffic loading can enable ...efficient and economical management of transport networks and is becoming a valuable tool for bridge safety assessment. B-WIM can provide site-specific traffic loading on deteriorating bridges, which can be used to determine if the reduced capacity is still sufficient to allow the structure to remain operational and minimise unnecessary replacement or rehabilitation costs and prevent disruption to traffic. There have been numerous reports on the accuracy classifications of existing B-WIM installations and some common issues have emerged. This paper details some of the recent developments in B-WIM which were aimed at overcoming these issues. A new system has been developed at Queens University Belfast using fibre optic sensors to provide accurate axle detection and improved accuracy overall. The results presented in this paper show that the fibre optic system provided much more accurate results than conventional WIM systems, as the FOS provide clearer signals at high scanning rates which require less filtering and less post-processing. A major disadvantage of existing B-WIM systems is the inability to deal with more than one vehicle on the bridge at the same time; sensor strips have been proposed to overcome this issue. A bridge can be considered safe if the probability that load exceeds resistance is acceptably low, hence B-WIM information from advanced sensors can provide confidence in our ageing structures.
In line with the critical movement that in the last two decades has led to an ‘aesthetic turn’ in the International Relations (IR) field, this article introduces the notion of geopoetics as a useful ...conceptual category for the analysis of peace, security, and politics. Conceiving geopoetics as an operative concept that helps to understand the political and social experience of geographical space through the most varied forms of artistic expression, this article investigates the work of the German filmmaker Wim Wenders, seeking to show how his filmography, when examined as a whole, constitutes a kind of geopoetic discourse of peace that offers an aesthetic critique, immanent to the very formal possibilities of cinematic technique that challenges dominant geopolitical and geostrategic approaches that continue to naturalise war and violence as necessary instruments of international politics. Relying on the concept of geopoetics and on the political relevance of cinema within the aesthetic turn observed in the IR field, the article argues that geopoetics contributes to expand the epistemological and methodological boundaries of the IR field and to developing a broader conception of peace in the discipline.
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