Road Train Research Articles

ПІДВИЩЕННЯ ПАЛИВНОЇ ЕКОНОМІЧНОСТІ АВТОМОБІЛЯ ЗА РАХУНОК ВИБОРУ ОПТИМАЛЬНОЇ МАСИ АВТОПОЇЗДА

The article considers the influence of the mass of a road train on its fuel economy. 241 The object of research is road vehicles that are in operation. Research method – analysis of fuel efficiency of cars. The purpose of the work is to determine measures to increase the efficiency of vehicle use by reducing fuel consumption. When transporting goods by road, the issue of substantiation of the mass of road trains and their fuel consumption is relevant. When carrying out transportation, the fuel consumption of a road train is influenced by many factors, the main of which are: the weight of the road train, road conditions and traffic regime. The following indicators can be used to assess the efficiency of car use: amount of fuel per 100 km; amount of fuel per 1 tkm, etc. But the most objective indicator is the specific fuel consumption Qp, ie fuel consumption per 1 km, attributed to the unit of transport productivity of the road train, Pi (tkm / h). Calculations performed on the example of road trains in the tractors KrAZ-260 and IVECO-190.48 show that the specific fuel consumption on the route Qpp with a total coefficient of resistance in the range Ψp = 0.04-0.06 at a load weight Mv = 40t is 0.8 and 0.8 ml, respectively. (tkm / year)), and at Mv = 70t, Qpp = 8.5 and 2.5 (ml / (tkm / year)). The calculation of fuel consumption depending on the equipped weight of cars of different brands is compared, comparing KrAZ-6510 and DAF-2700 cars. To reduce the curb weight, you must, first of all, carefully analyze the layout and mass characteristics of all components and units, widely use lightweight and high-strength materials. The results of the article can be used in the operation and improvement of car design.KEY WORDS: CAR EQUIPMENT, FUEL ECONOMY, MOVEMENT RESISTANCE, FUEL CONSUMPTION, EFFICIENCY OF OPERATION

Influence of a trailer with a rigid drawbar on the distribution of the load along the axles of the vehicle

Requirements for vehicles to limit the permissible axle load are increasing and are being monitored more with automatic detecting devices. In this regard, in some types of road train layouts, there are risks of exceeding the standard values of axle loads. One of such combinations of road trains are vehicles with trailers with rigid drawbars. This article discusses the distribution of the load on road trains with trailers with a rigid drawbar, a model is presented that allows uniform loading of the road train. Keywords: coefficient of influence of the trailer, towing hitch, axle load of the vehicle, carrying capacity, utilization factor of carrying capacity, location of the load

Evaluating the effects of automated monitoring on driver non-compliance at active railway level crossings

Collisions between road users and trains at urban railway level crossings persist, despite active protection. The number of railway level crossings in most settings render their removal unfeasible. To effectively reduce or manage risk, alternative treatments are required. Increases in road and rail traffic invariably result in congestion issues at urban railway level crossings, which influences non-compliances by road users. Automated enforcement is one form of treatment that is being considered to reduce such non-compliances. This study conceptualised and adopted a before—after design to evaluate the effect of a conspicuous monitoring system on non-compliances by vehicular road users at an active level crossing. Baseline measurements of vehicle movements and level crossing status were recorded for two months. Conspicuous cameras and radar were subsequently installed, and a further month of data was recorded. Non-compliances with flashing lights were extracted and arranged into “must stop” and “should stop if safe to do so” categories, aligning with road rules at traffic lights. Non-compliances frequently occurred (N = 1,086) with most (94%) of the latter category and ascribed to a lack of an advanced warning before crossing closure. Analysis with Generalised Linear Models revealed that non-compliances where drivers must stop reduced by 36% (from 13.4% to 8.6%) following the introduction of a conspicuous automated monitoring system, even though no actual enforcement was performed. This study suggests that non-compliances at railway level crossings have the potential to be reduced through the introduction of automated enforcement similar to the one used at traffic lights.

Exploring multiple crowdsourced data to learn deep convolutional neural networks for road extraction

Road extraction from high-resolution remote sensing images (HRSIs) is essential for applications in various areas. Although deep convolutional neural networks (DCNNs) have exhibited remarkable success in road extraction, the performance relies on a large amount of training samples which are hard to obtain. To address this issue, multiple crowdsourced data are used in this study, including OpenStreetMap (OSM), Zmap and GPS. And a multi-map integration model (MMIM) is developed to improve the noise robustness of DCNNs for road extraction tasks. Specifically, rich geographical road information are obtained from multiple crowdsourced data, including main roads, new construction roads, midsize and small roads, which can generate complete road training samples and reduce the label noise. Meanwhile, by exploring the true road label information hidden in different crowdsourced data, the MMIM is used to generate high-quality refined labels for learning DCNNs. In this case, the DCNN-based road extraction methods have more opportunities to learn true road distribution and avoid the overfitting problems of label noise. Experiments based on real road extraction dataset indicate that the proposed method shows great performance, and road extraction results are smoother and more complete.

Road safety and heavy goods vehicle driving in LMICs: Qualitative evidence from Nepal

BackgroundHeavy goods vehicle drivers are an influential driving population in Nepal, with over 90% of goods in the country are transported by road. Due to the time spent on the road, drivers have long periods of exposure to the risk of crash involvement. The study explores the perceptions and experiences of heavy goods vehicle drivers and representatives from their professional association regarding road danger. MethodsWe conducted semi-structured interviews with fifteen heavy goods vehicle drivers regularly driving on the East-West highway of Makwanpur District, Nepal. A focus group was conducted with eleven members from a major transportation entrepreneur's association in Nepal. The focus group and interviews were audio-recorded, transcribed, translated, and analyzed using thematic analysis. ResultsFour themes were developed- assumptions of blame; perceptions of safety culture in the trucking industry; influence of road infrastructure; and behaviours of road users. The road and traffic environment, enforcement, and the safety culture in the heavy vehicle industry not only influenced the attitudes of the road users towards traffic safety but also legitimized and encouraged behaviours that affect safety. General and industry-related road safety improvements suggested by participants included: making provision for heavy good vehicles parking areas, separating the highway with a median strip, improving crash investigation capacity, conducting road safety awareness and training programs, strictly enforcing the speed limit and laws about driving under the influence of alcohol/drugs, and formulating strategies to create a safe, supportive working environment in the heavy vehicle industry. ConclusionHeavy goods vehicle drivers and members of the professional association can provide rich information regarding the barriers and facilitators of road risk in Nepal. Their perceptions and opinions can contribute to devising interventions at individual, societal, organizational, and governmental levels, and inform efforts to develop a positive safety culture within the heavy vehicle transport industry.

ПОВЫШЕНИЕ УСТОЙЧИВОСТИ ДВИЖЕНИЯ ПРИЦЕПНЫХ АВТОТРАНСПОРТНЫХ СРЕДСТВ

Today, automobile and tractor trains with trailers are quite popular vehicles used for transporting agricultural goods in the agro-industrial complex of the Russian Federation. Road trains and trac-tors with trailers are characterized by lower performance indicators (maneuverability, stability of movement) than single vehicles. Accordingly, special requirements for safety and trouble-free op-eration are imposed on motor-tractor trains. The author of the article proposes a technical solution that provides longitudinal stability of the movement of multi-link trackless vehicles, and has, in comparison with known analogues, simplicity of design and increased efficiency in the operating conditions of multi-link tractor trains. Analytical studies have been carried out, which made it possible to justify the rational kinematic and geometric parameters of the proposed technical solu-tion. The strength parameters of the damping device installed at the coupling point of tractors and trailers, and ensuring the operational reliability of trailed dump vehicles, are determined. The re-sults of the conducted research are recommended to both domestic and foreign research institutes, design and production structures of the automotive industry for further study and refinement of the proposed device with a view to its possible introduction into practice.

Research on dependence of fuel consumption on cargo weight in long-distance transport

Introduction. The current methodology for fuel consumption accounting in road vehicles has not been changed in terms of its quality for a long time. In the majority of transport enterprises of the Cheliabinsk Region, official methods for the regulation of fuel consumption are not used, which indicates the need to improve the fuel consumption accounting standards. The most significant differences between standardized and real consumption are related to transport work.Purpose of the experiment. The article aims to carry out a statistical analysis of the influence of cargo weight on fuel consumption in long-distance transport.Results of the experiment. In order to identify the dependence of cargo weight on fuel consumption in longdistance transport, a study is conducted on the statistical data on the operation of truck tractors at OOO Alliance Auto, one of the largest long-distance road carriers in the Cheliabinsk Region. The study is conducted on MercedesBenz Actros-1840 truck tractors equipped with fuel consumption monitoring devices and devices for determining axle loads. The cargo weigh is determined by subtracting the curb weight from the actual one according to the axle load data. Data on the values of the actual cargo weight and fuel consumption for each trip are recorded using the Fleet Board software and hardware complex; Excel and STATISTICA programs are used to calculate and construct the necessary graphs and regression equations. The statistical analysis performed makes it possible to establish the nature and indicators of the dependence of fuel consumption on cargo weight in long-distance transport. As a result, the relationship between the flow rate and the cargo weight is established; a confidence test is performed; and a regression equation is obtained.Conclusion. Analysis of the collected data shows that the dependence of fuel consumption for transport work by road trains with truck tractors Mercedes-Benz Actros-1840 on the cargo weight for the Russian operating conditions in long-distance transport is linear and amounts to 0.39 liters per 100 km for each ton of transported cargo.

Adoption of Improved Maize Varieties as a Sustainable Agricultural Intensification in Eastern Ethiopia: Implications for Food and Nutrition Security

This paper examines factors determining farmers‘ adoption decision for improved maize varieties in the maize-common bean intercropping practices in two districts of East Hararghe zone, Eastern Ethiopia. It is based on data collected from 129 farm households using structured questionnaire. Descriptive results revealed that adopters of improved maize varieties had better food and nutrition security status. Furthermore, logit model output indicated that the decision to adopt improved maize varieties is influenced by location (district) dummy, education status of the household head, age of the household head, distance from the main road, and the number of plots owned. Major recommendations include improving the rural road infrastructure, educating and training farmers, organizing experience sharing events among farmers, and raising awareness about the food and nutrition security benefits of sustainable agricultural intensification practices like intercropping improved maize with improved common bean varieties.

Commentaries on Viewpoint: Fragile bones of elite cyclists: to treat or not to treat?

Commentaries on Viewpoint: Fragile bones of elite cyclists: to treat or not to treat?

МОДЕЛИРОВАНИЕ РАБОТЫ РЕКУПЕРАТИВНОГО ПРУЖИННО-ГИДРАВЛИЧЕСКОГО СЕДЕЛЬНО-СЦЕПНОГО УСТРОЙСТВА, РАЗМЕЩЕННОГО В ПОЛУПРИЦЕПЕ ЛЕСОВОЗНОГО АВТОПОЕЗДА

The substantiation of the necessity of using timber trucks, consisting of timber tractors with semi-trailers, when transporting timber, is given. Attention is focused on improving the efficiency of the functioning of log trucks by con-structive improvement of the fifth-wheel couplings used in them. The analysis of scientific works of foreign scientists engaged in the study of the influence of fifth- wheel coupling on the efficiency of log trucks is carried out. A promising scheme of a recuperative spring-hydraulic fifth-wheel coupling, located in the front part of the semi-trailer frame of a timber tractor, is proposed, which has significant advantages in comparison with other similar devices. At the first stage, a mathematical model of the proposed fifth-wheel coupling was developed; at the second stage, a computer program for a preliminary assessment of the efficiency of the functioning of a timber tractor with a semitrailer equipped with a recuperative spring-hydraulic fifth-wheel coupling is made. The dependences of the change in the average values of the recuperative power and longitudinal acceleration of the trailer relative to the timber tractor on the inner diameter of the hydraulic cylinders of the recuperative device, the mass of the semi-trailer and the frequency of braking and accelera-tion of the timber road train are obtained. It was revealed that the optimal diameter of the hydraulic cylinders of the recuperative device for the given conditions, providing the maximum recuperative power, should be in the range of 50-60 mm. It was found that with an increase in the mass of a semitrailer of a logging tractor, as well as with an increase in the frequency of braking and acceleration, an increase in the recovered power is observed

СОВЕРШЕНСТВОВАНИЕ СИСТЕМЫ РЕКУПЕРАЦИИ ЭНЕРГИИ ЛЕСОВОЗНОГО ТЯГАЧА С ПРИЦЕПОМ-РОСПУСКОМ

The place of road transport in logging production has been considered. The main advantages of using timber tractors with timber drags in comparison with other layout schemes of timber road trains have been described. Conse-quences of dynamic loads acting on the pivot of the turning bunk of a timber-carrying area from frequent braking of a timber tractor with a timber drag have been given. Based on the analysis of scientific works of foreign scientists, the promising direction of research in the field of recuperation of various types of energy in road transport is substantiated, which makes it possible to reduce dynamic loads during braking in the pivot pin and at the same time accumulate, with subsequent useful use, energy unproductively dissipated into the surrounding space from the energy forces of the trailer with a pack of whips. The design of the main manufacturers of platforms for timber haulers with timber drags has been described. The requirements for timber haulers with timber drags operated on public roads have been considered. The main forces acting on the links of a timber tractor with a timber drag during braking have been analyzed. Diagrams of the mutual positions of a timber tractor with a timber drag when moving along a timber road on the rise, downhill and turn have been given. The analysis of the dependences of the forces arising in the pivot of the swivel bunk of a timber platform during the movement of a timber tractor with a timber drag on the turning radius and speed of movement has been carried out. A promising design of a recuperative bolster device for a timber haulage site has been proposed. It enables to accumulate hydraulic energy during frequent braking of a timber tractor with a timber drag, followed by its use in the process of loading and unloading timber by a hydraulic manipulator

Simulation analysis of transport energy efficiency of road trains and international motor transportations

The object of the study is the production and technological processes of international road transport (PTP IRT) according to the innovative approach and the conceptual idea of technical and technological energy saving in motor transport. Predictive assumptions about the development of the object of study – the realization of the possibilities of operational-simulation and technical-evolutionary method of complex analysis of transport energy efficiency of road trains and production and technological processes of international road transport in the practice of international road transport. In the course of the research the operational-simulation and technical-evolutionary method of complex analysis of transport energy efficiency of road trains and production-technological processes of international road transportations was considered. As an example, the influence of changes in such a design parameter of the road train as the gear ratio of the main transmission of the tractor on its transport energy efficiency, as well as fuel and energy consumption of the road train DAF FT95.360 (Netherlands) in the test trunk operation (at αg=0). It is established that when the value of the gear ratio of the main transmission (Uo) increases, the value of the energy efficiency indicator (Pe) varies from 0.55 to 0.58. The greatest value of energy efficiency is at Uo=2.846. It is determined that when the value of the gear ratio of the main transmission (Uo) increases, the value of the energy consumption indicator (Ac) increases, and the minimum value of 3.2 MJ acquires the value of the gear ratio of the main transmission – 2.846.It was found that when the value of the gear ratio of the main gear (Uo) increases the fuel consumption (Qc) increases and acquires a maximum value of 3496.84 g with the value of the gear ratio of the main gear – 4.39. The minimum value of fuel consumption of 1684.2 g is achieved when the value of the gear ratio of the main transmission 2.846. The results of the study can be used to implement systemic and conceptual innovation management in the field of international road transport.

Evaluation of the Impact of Timber Truck Configuration and Tare Weight on Payload Efficiency: An Australian Case Study

The forest industry tends to plan, and model transportation costs based on the potential payload benefits of increased legal gross vehicle weight (GVW) by deploying different configurations, while payload benefits of a configuration can be significantly influenced by the vehicle design tare weight. Through this research the relative benefit of increased legal GVW of different configurations is compared across Australia over a 13-year period from 2006 to 2019, by examining data collected post operation across multiple operations. This approach is intended to offer realistic insight to real operations not influenced by observation and thus reflect long-term operating behaviour. The inclusion of the three most common configuration classes in Australian forestry over a 13-year period has also allowed the exploration of load management between configurations and potential trends over time. When considering the legal GVW and the tare weight impacts across the fleets, the semi-trailer has an 8 t payload disadvantage compared to B-Doubles and 19.6 t disadvantage compared to road trains.

ON THE QUESTION OF BRAKING ARTICULATED BUSES

The safe movement of a car and a road train is largely determined by its braking properties. The nature of the movement of the road train is fundamentally different from the movement of a single car. The difference can be explained by the presence of additional forces arising in the articulation of the links of the vehicle, as well as forces and moments acting on its individual links and the movement of the vehicle as a whole. Their effect is especially noticeable when braking a road train, which may be accompanied by folding links and loss of stability of the vehicle. As a result of the study, the optimal values of the brake force distribution coefficients for a fully loaded articulated bus are obtained, which provide both high braking efficiency and the stability of the articulated bus (AВ) during braking. The coefficients are determined taking into account the design features of the brake mechanisms and their geometric dimensions, providing the required braking performance. For the selected values of the braking force distribution coefficients along the axes of the AВ and the coefficients that take into account the design features of the braking mechanisms and their geometric dimensions, the braking distance during braking by the main or working braking system and the spare one satisfy the requirements of regulatory documents. With the selected asynchronous response of the brake drives of the bus and trailer, the steady deceleration of the АВ is slightly less than the standard.

Seasonal variation in North American level crossing crash rates is due to weather, not day length

Objective Collisions between road vehicles and trains at level (grade) crossings can be devastating. Injury and economic considerations make prevention efforts of significant interest to society at all levels, and raise important safety concerns. Improving our understanding of the nature and pattern of crashes at level crossings can help inform a variety of types of safety mitigation strategies, including public education, crossing equipment and vehicle design efforts. Method To this end, a database search of Canadian level crossing crashes for the 11-year period between 2007 and 2017 was conducted to confirm a previously identified seasonal variation in the frequency of level crossing crashes. To determine whether the observed winter increase in crashes was due primarily to winter reductions in light levels/day length or to other seasonal weather factors, a subsequent comparison of Canadian data to American Federal Railroad Administration (FRA) crash data was carried out. A separate inferential log-linear model analysis, using season, time of day and crossing protection type, was also used to explore the increase. Results As expected, the average rate of crossing collisions in Canada increased during winter months compared to non-winter months. While the seasonal pattern was evident in those U.S. states that experience significant changes in weather patterns (i.e., northern states), it was almost completely absent in those states that do not (i.e., southern states). The log-linear model analysis confirmed these findings. Conclusions The seasonal variation in North American level crossing crash rate is a result of winter weather conditions, rather than differences in light levels. Future research is planned that will elucidate the specific environmental and human factors contributing to the increase.

A comprehensive mathematical model and the methodology for assessing technical excellence road trains with active links and all-wheel control

This article presents the main provisions of the new scientific and methodological approach, integrated mathematical model and methodics assessing the technical perfection of wheeled transport means of particularly large capacity based on road trains with active links and all wheeled steering. The results of the research allowed us to justify scientific and methodological approach to the assessment of technical excellence wheeled transport means of particularly large capacity based on road trains with active links and all wheeled steering, which includes implemented conceptual apparatus, scientific concepts and principles, theoretical and practical provisions. Results of justification and developing integrated mathematical model include the total mass equations, and methodics wheeled transport means of particularly large capacity based on road trains with active links and all wheeled steering. Introduced the concept of the integrated mathematical model, justified and developed by the integrated mathematical model wheeled transport means of particularly large capacity based on road trains with active links and all wheeled steering, in which includes the equation of the total mass of transport means in absolute and relative values, equations of dynamics of sprung and unsprung masses of links of wheeled transport means, equations of joint dynamics of wheeled transport means taking into account the applications of the saddle device and all-wheel control, models of interaction of wheel propellers with the support surface, models of the micro-profile and macro-profile of the support surface, and other component parts united comprehensive model. On the basis comprehensive mathematical model proposed metodics assessment of the technical excellence of the road train with active links and all-wheel control, recommendations on the choice of indicators and evaluation criteria are justified.

A method for assessing the cross-country capability of a particularly heavy-duty vehicle with all-wheel control based on the compliance of the support surface during curved movement

The article presents a method for assessing the permissible speed of a particularly heavy-duty vehicle based on a road train using a combined hydraulic transformer in the tractor transmission, as one of the indicators of cross-country ability. In this paper, we consider one of the main ways to increase the cross-country ability of heavy-duty vehicles: the creation of heavy-duty vehicles based on a road train with an active trailer link. Increasing the passability of heavy-duty vehicles is primarily aimed at increasing the permissible speed of heavy-duty vehicles and the maximum angles of ascents to be overcome. When justifying the choice of an algorithm for controlling the voltage of a torque Converter inductor based on the speed of particularly heavy-duty vehicles, it is advisable to use the external characteristics of the torque Converter as evaluation indicators: the dependence of the efficiency coefficient, the dependence of the moment created by the pump, and the dependence of the transformation coefficient on the gear ratio of the torque Converter. As criteria for evaluating the feasibility of using a combined torque Converter for especially heavy-duty vehicles, it is advisable to use the maximum increase in efficiency, the moment created by the pump wheel, and the transformation coefficient of torque converters on magnetic fluid in relation to the efficiency, the moment created by the pump wheel, and the transformation coefficient of the torque Converter based on a conventional working fluid in the operational range of gear ratio changes. The external characteristic is calculated after calculating the blade system and selecting the design to determine whether the main parameters of the characteristic correspond to the parameters specified in the task for designing the torque Converter. Such calculations often have to be performed when fine-tuning torque converters with a known design, when the influence of geometric parameters of individual elements of the blade system (input and output angles, wheel radii, the number of blades in the impellers, etc.) on the transforming and loading properties of the torque Converter is investigated.

An Adaptive Game-Based Learning Strategy for Children Road Safety Education and Practice in Virtual Space.

Virtual reality (VR) has been widely used as a tool to assist people by letting them learn and simulate situations that are too dangerous and risky to practice in real life, and one of these is road safety training for children. Traditional video- and presentation-based road safety training has average output results as it lacks physical practice and the involvement of children during training, without any practical testing examination to check the learned abilities of a child before their exposure to real-world environments. Therefore, in this paper, we propose a 3D realistic open-ended VR and Kinect sensor-based training setup using the Unity game engine, wherein children are educated and involved in road safety exercises. The proposed system applies the concepts of VR in a game-like setting to let the children learn about traffic rules and practice them in their homes without any risk of being exposed to the outside environment. Thus, with our interactive and immersive training environment, we aim to minimize road accidents involving children and contribute to the generic domain of healthcare. Furthermore, the proposed framework evaluates the overall performance of the students in a virtual environment (VE) to develop their road-awareness skills. To ensure safety, the proposed system has an extra examination layer for children’s abilities evaluation, whereby a child is considered fit for real-world practice in cases where they fulfil certain criteria by achieving set scores. To show the robustness and stability of the proposed system, we conduct four types of subjective activities by involving a group of ten students with average grades in their classes. The experimental results show the positive effect of the proposed system in improving the road crossing behavior of the children.

Analysis of model for assessing the road train movement stability

In this paper, we conduct a mathematical analysis of the model of ensuring the road trains movement stability by changing the design of coupling devices to determine the critical characteristic parameters of the road trains, which result in the loss of en-route directional stability under external action. The concept of the model was to separate the process of yawing of the road trains and its elements (due to external perturbing action) on the highway into several typical stages. The main parameters of the stages (the displacement amplitude and rotation angle of the road trains elements in relation to the driving direction) were determined based on the initial conditions of the road trains movement, the force and duration of the external action. The most dangerous areas of external action application to the road trains were determined in this paper. The maximum permissible exposure limit should not exceed 0.5–1.0% of the road trains trailer momentum, with duration having the greater effect than the amount of impact. The results obtained can be used in mechanical engineering to improve the road trains performance.

Development and research of adaptive control algorithm for road train lateral motion

In the presented work, the problem of control of a road train when it performs various maneuvers while moving along the highway is considered. An adaptive algorithm for controlling the lateral displacement of road train elements is proposed, based on the use of a PD-controller, the values of the coefficients of which depend on the current value of the longitudinal velocity. Computer simulation has been carried out, which has shown the correctness of the proposed algorithm.