No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Solving the multi-criteria problem of choosing a vehicle using analytical models
Abstract
A vehicle as an object of increased danger is highly susceptible to violation of operating rules, which causes a decrease in its level of safety and environmental friendliness. Safety-enhancing components, assemblies, and systems increase design complexity and the cost of maintaining a vehicle in good condition, which in turn significantly increases the cost of spare parts and components. Maintenance of these units reduces their maintainability. To assess the life cycle of a vehicle, it is necessary to test its service life management system in dynamically changing environmental conditions. In terms of these problems, the choice of a solution depends on the state of the environment and involves solving a number of multi-criteria problems using various methods of optimization and mathematical modeling. To increase the reliability level of decisions necessary in the service life management system of a vehicle, it is advisable to develop an analytical apparatus based on linear programming methods and the search for a set of Pareto optimal solutions (development of zoning methods), which will make it possible to arrive at optimal decisions given insufficient data on the operating conditions of the vehicle. The study represents an attempt to use a new mathematical apparatus for qualitative identification of the impact of external relations determined by the vehicle operating environment directly on the nature of the technical operation of the vehicle. Both processes are considered as complex dynamic systems forming connections, therefore it was necessary to adapt a number of existing approaches to solving multi-criteria problems of technical operation of vehicles necessary for the consistent implementation of computer modeling for the operation of the service life management system of a vehicle.
... The solution to the problem consists in determining such coefficients of relative importance C ij , which ensure the maximum performance value. Fishburn method is used to determine the weighting coefficients [6,8], which assess the n-th number of properties. To determine the level of performance, each parameter (optimization criterion) x i (i = 1, n) is matched with an estimate of its significance. ...
... The solution to the problem consists in determining such coefficients of relative importance , which ensure the maximum performance value. Fishburn method is used to determine the weighting coefficients [6,8], which assess the n-th number of properties. ...
... The criteria were placed in order of decreasing importance (in our research, it is the performance of MROS operation for a discrete period). After ranking, the weight indicators were determined using the Fishburn scale [6,8]. ...
Current situation with the fleet of transport and technological machinery in Ukraine requires an individual approach to evaluating the effectiveness of its maintenance and repair system. The article is devoted to the issue of selecting the most effective option for the use of transport and technological machinery taking into account the specific conditions of its operation characterized by certain risks and uncertainties, and considering the real volumes and age structure of the fleet. Solving this problem requires substantiation of management models of maintenance and repair processes. It is necessary to provide scientifically based methods of managing the system of technical maintenance (TM) and repair of transport and technological machinery (RTTM) using specific methods of an individual approach to the technical and economic evaluation of the effectiveness of maintenance and RTTM processes which are adapted to the modern conditions of its operation. The article presents the results of the research, which was carried out using the basics of system analysis, the theory of decision-making under the conditions of uncertainty, and the basics of multi-criteria analysis. In the course of research, an analytical management model of the maintenance and repair system operation was formed that reveals the sequence of implementing the management methodology, which makes it possible to assess its state in successive discrete states, to promptly take into account the effect of external influencing factors and make corrections, which, in turn, allow increasing the validity of strategic decisions aimed at increasing the effectiveness. A numerical calculation was performed, which allowed us to conclude that the value of maintenance intervals has a significant impact on the indicator of effectiveness. Adjusting this value makes it possible to optimize maintenance and repair processes.
Unmanned aerial vehicles initially designed to satisfy the needs of military organizations have significantly expanded their functional purpose during the past decades and are now used by many government institutions and bodies addressing a wide range of organizational, strategic and prognostic issues. Studying the equipment capability of government institutions participating in road traffic safety facilities resulted in a conclusion that unmanned aerial vehicles are intensively used when addressing organizational, administrative, operative, analytical, preventive and tactical-technical issues. Payload elements of modern aerial vehicles enable dealing with planning, construction and operation of motor ways, situational and prediction modeling of traffic flows in order to ensure population mobility, monitoring of climatic conditions and environmental situation, and help addressing the issues of crime prevention, promoting detection and investigation of road safety offenses. Unmanned aerial vehicles are an element of an intellectual transport system comprising modern informational, communication and telematic technologies. These aerial vehicles provide for automated search, recording and reception of information for automated processing, which allows for efficient monitoring of road transport system and groups of vehicles in the conditions of certain spatial and time parameters in order to ensure transport mobility of population and road safety in general.
A multicriteria approach with temporal indicators in optimizing the distribution of cargo flows in multimodal transport and technological system is presented. Based on the infrastructure indicators of the considered part of the railway landfill and the economic and geographical volumes of cargo accumulation, a mathematical model of the transport process is developed, expressed as a nonlinear integer programming problem. For various combinations of several objective functions, which are temporary indicators of the transportation process, an algorithm of optimal distribution of cargo flows for the considered loading stations and unloading stations is developed. Computational procedures for finding the Pareto optimal distribution of cargo flows are implemented in the environment of a computer mathematics system, which can be Free Ware. The distribution of grain cargo flows, which, as well known, are especially relevant from a commercial point of view for Russian exports, was chosen as a specific object for implementing the developed optimization approach.
The article suggests new approaches to assessing and predicting the human factor in normal and extreme conditions. The authors point out that there are powerful and stable behavioral characteristics that do not depend on the state of transport experts at a particular moment, certain conditions, and duration of work. Upbringing and value system are the fundamental factors that predetermine human behavior both in normal and extreme conditions. Professional qualification and psychophysiological state of each expert can affect their capabilities to a certain extent; however, the safety of actions will always be determined by the moral criterion of their professional motivation and willpower.
The authors develop a unified approach to the substantiation of requirements for the automated traffic control system as a “measurement equipment – identification – vehicle traffic control” system. Studies show that to establish requirements for vehicle identification systems, it is reasonable to use a method for the substantiation of technical requirements and the evaluation of the performance of measurement equipment in automated vehicle traffic control systems based on multi-criterion optimization consisting in the selection of an optimal solution from a defined area of search. The developed method of the automatic vehicle identification system shows high performance for a detection system in real-time. Most previous papers were based on one method: method of template matching or neural network method, which is ideal for the detection of some types but not suited for the detection of others.
Transport and handling machinery based on automobile chassis used for construction and operation of roads represents a high risk. The operational safety of such technical systems is ensured by high requirements for their reliability. The article describes a method to form vehicle fleets based on reliability as well as technical and economic indicators.
This article describes the basic components and functional capabilities of a testing range that is planned to be created in Russia. With such a testing range, it will be possible to move to a whole new level of development and implementation of technical and technological components in such areas of promising intelligent transportation systems as cooperative interaction and unmanned traffic. The authors highlight that it is important to establish a systemic approach to prototype testing, the formation of a regulatory base and the establishment of a unified authority for the certification of developed technologies. Besides, the article describes the global experience in creating testing ranges to test performance and safety of advanced communication technologies, technologies of cooperative interaction (between vehicles as well as between vehicles and road infrastructure) and technologies of highly automated and unmanned vehicles as well as their role in the development of promising intelligent transportation systems.
Natural gas is of the most interest out of a whole range of currently used motor fuels since it can reduce harmful emissions to the atmosphere. The impact large vehicle fleets have on the environment is, as a rule, higher than the impact of private motor vehicles due to large annual mileage. A single management center for such fleets can provide more reliable information on the operating conditions of vehicles, and replacement of diesel engines with gas ones in vehicle fleets of large cities will improve the environmental conditions of urbanized areas. The article analyzes potential consumers of compressed-gas trucks in cities. The migration of vehicles of utility companies to natural gas will reduce the volume of harmful emissions to the atmosphere and the noise level at garbage pickup in the morning. Studies on the safety of compressed natural gas (CNG) vehicles have confirmed its high level. Nevertheless, reliability matters remain relevant. The suggested method for prediction of possible failures and service planning, as well as prediction of operating conditions will take into account the prospects of enlargement of gas-engine vehicle fleets and the ways to reduce the environmental load.
Based on the analysis of theoretical as well as experimental and computational studies on the nature of origin, morphology of the physical structure, chemical composition, and diffusion of PM2.5 diesel soot particles of dangerous sizes in a stratified atmosphere, the authors present data on the expected level of air pollution with suspended black carbon particles near the Saint Petersburg Ring Road in extreme weather (wind speed — less than 2 m/s, stable temperature inversions in the surface layer of the atmosphere) and transport (peak hour traffic) conditions. The experiments prove that due to the developed, physically active internal surface of primary soot particles, determined by the local values of the air/fuel ratio (λ up to 0.4) and flame temperature (up to 3500 K) in heterogeneous diffusion fuel combustion, pores in diesel exhaust black carbon deposits accumulate (adsorb) up to 0.015 ± 0.006 mg/kg of benzo[a]pyrene (С20Н12, a polycyclic aromatic hydrocarbon, which, according to the WHO criteria, is the most dangerous for the urban population); 17.5 ± 3.7 mg/kg of lead compounds; 0.5 ± 0.2 mg/kg of cadmium; 104 ± 48 mg/kg of nickel; 156 ± 28 mg/kg of chromium. The authors analyze the data on the digital monitoring of the traffic intensity of trucks with diesel engines, using their proprietary method, and draw the following conclusions: under the mentioned extreme conditions, near the Saint Petersburg Ring Road, we can expect the formation of local areas of air pollution (at the breathing level) with PM2.5 soot particles at the level of up to 2.5 MACms (maximum single allowable concentration); and with account for the measured С20Н12 content in the structure of diesel exhaust black carbon deposits and its MAC values in the air of urban areas in Russia (daily average MAC = 0.1 µg/100 m³) — at the level of up to 20 MACda (daily average). Given the tendency for the approximation of operating conditions, the technical state of vehicles, and the environmental performance of fuel in Saint Petersburg to the countries of the European Community, we can expect the representativeness of the research results in the largest cities of the world.
The article considers whether it is possible to continuously monitor the technical condition of vehicles in operation without significant changes in their design. We analyze a list of faults and parameters to be controlled to ensure continuous monitoring of the technical condition of Isuzu 4FH1 diesel engine supply system elements. The results of simulating the fuel injection process using Star-CCM+ software are presented. The results of an experimental analysis of crankshaft position sensor readings confirming the simulation results are presented as well.
The article addresses the concept of human-machine interface operation and problems solved during interface design. We provide a general description of problems related to the drivers’ readiness to enhance the automation level of vehicles. A basic algorithm of human-machine interface operation for an automated vehicle is described.
The article addresses relevant issues of vehicle traffic management when using operational and technical monitoring systems in the field of traffic safety assurance. The authors provide a rationale for promising directions of traffic management system improvement using automated traffic enforcement facilities to record traffic violations. The operation of a system of technical means of monitoring is modeled. A method to evaluate the efficiency of traffic enforcement system management is proposed. It allows us to determine the implementation degree of management functions assigned to the monitoring system in the field of traffic safety assurance. A stochastic model is developed to evaluate the performance of departments that ensure traffic monitoring using automated traffic enforcement facilities. The results of the study conducted include the developed model as well as a method and algorithm for optimizing the structure of the system managing operational and technical means of vehicle traffic monitoring.
This paper covers the parallel arrangement of the diagnostics process across a set of similar discrete objects with a partial test reversal. In this case, the discrete objects are the digital nodes of vehicle information systems.
We prove that it is possible to reduce the time spent on tests, and thus the time spent on the overall object set diagnostics as well. We demonstrate that parallel diagnostics with a partial test reversal offers more benefits than simple parallel diagnostics, as far as gain in time is concerned.
The safe use of ambulance vehicles is ensured by a number of factors, one of which is a proper technical condition of the suspension components, meeting the current requirements of megacities (Dezhurny et al. 2010, Yurkovskiy 2010). These requirements force us to analyze the efficiency of using standard oil twin-tube shock absorbers, as well as their most common types such as hydropneumatic shock absorbers and air suspensions. The results of the study show that single-tube hydropneumatic shock absorbers are the most efficient in terms of stability and running smoothness, which directly affects operational safety. Their use does not require any changes in the design, making it easier to replace standard shock absorbers.
This paper reviews the environmental hazard factors associated with car tires throughout their service life, looking at how the technological parameters of tire manufacture and use impact human health, and how the processes of using, selling, and disposing of tires can be regulated and improved in the future if chemical pollution of the environment is to be reduced. We calculate the loss of tire mass and material, and use our findings to determine the relative level of air pollution by tire dust. We also draw attention to the lack of transparent and organized efforts to properly dispose of car tires. To address this, we design an organizational chart for an international system that could control the use of car tires, including an algorithm for an operating procedure aimed at minimizing the hazard that arises when the decommissioned tire disposal process is improperly structured or absent altogether. Finally, we define the role that tire dealerships could play in this system. We propose a formula for calculating the annual tire use balance within the environmental safety control system.
Continuous development of transport infrastructure raises requirements for transport safety. Road transport is the most emergency-prone and leading in the number of tragic consequences as well as financial and physical damage. Many accidents transform into emergencies (these include accidents with fatalities of at least 5 people or with the number of injured of at least 10 people). Damage from emergencies depends on the quality of managerial decisions taken at the response of rescue services. To solve the problem of taking qualitative managerial decisions, it is suggested to create an intelligent system based on expert knowledge and analysis of data from multiple precedents. It is suggested to use an artificial neural network that would solve the classification problem in the assessment of the scale of an accident or emergency. The decision on the number of emergency response manpower and resources and their distribution for accident or emergency response is made on the basis of such assessment.
The article suggests a concept to account for changes in freight tariffs due to weather and road conditions on the basis of the assessment of freight accelerations. We derive general mathematical models that describe changes in tariffs depending on weather and road conditions. A change in the driver’s role when making a decision to optimize the route is shown.
This paper covers the results of monitoring active safety systems during vehicle operation.
The analysis of the existing diagnostic methods for active safety systems in operation shows that on-board diagnostics of active safety systems does not cover the entire list of possible malfunctions.
It is also worth considering that the electric drive systems of active safety systems are an integral part of the vehicle’s braking system influencing traffic safety during operation.
This issue can be resolved by supplementing the monitoring process with an additional diagnostics complex. This monitoring system receives data on the working processes of the vehicle automated systems’ components in real time.
An important difference from existing diagnostic systems is the ability to determine the exact malfunction of a vehicle’s automated system component, as well as to establish the cause of the malfunction, allowing the system to reduce the possibility of a recurring malfunction and improve traffic safety.
Coupled together with a data-sharing interface, this monitoring system enables the creation of the active vehicle’s digital twin. We provide an example of how this simulation technology, based on a fusion of virtual and physical elements, helps study vehicle performance in complex, multi-factor operation modes.
This diagnostic system, used in combination with a bench chassis model, makes it possible to adapt the system if the manufacturer adjusts the vehicle’s automated system design, thereby simplifying the process of further verification of the digital twin.
As automation grows more and more widespread, the use of such systems becomes more and more relevant.
The article addresses the evaluation of the impact of regenerative braking on fuel consumption and, consequently, on pollutant emissions from vehicles operated under conditions leading to frequent acceleration and deceleration. We assume that the vehicle is equipped with a system of conversion and accumulation of electric energy obtained only from braking. Basic analyzed characteristics are determined by a comparison of gasoline engine operation modes with braking energy recovery and without it. As initial physicomathematical tools, we use relationships of propulsion power and energy analysis and propulsion drive operation, which were previously suggested by one of the authors. As an example of using the mentioned relationships, the article presents the analysis results for a vehicle moving in the low-speed segment of the WLTC driving cycle. Energy passing through the battery and energy reserve in it are calculated. It is assumed that the accumulated braking energy makes it possible to start moving at the next segment not using the gasoline engine; the engine starts its operation only after the energy in the battery is exhausted. Superposition of the curves of gasoline engine operation modes with and without recovery allows us to estimate changes in the energy generated. In order to account for different values of specific fuel consumption, the authors use an adjustment factor, which takes into account pollutant emissions from the vehicle depending on the average speed. Functions of changes in fuel consumption and pollutant emissions when using regenerative braking are obtained by the integration of values. The authors compare the obtained results with the results of road tests of vehicles with the energy recovery system. The materials suggested expand our knowledge of the operational properties of vehicles with electromechanical and electrical power units
The technical condition of vehicles may result in road traffic accidents (RTAs) with the most severe consequences. In this connection, despite the statistically low share of such accidents in the overall number of RTAs, systems for the inspection of the technical condition of vehicles in operation by traffic safety parameters are organized and operated. The article suggests a formal mathematical approach to evaluating the efficiency of such systems. We describe the existing organization of systems based on periodic inspection. We also describe the state of the Russian system for the inspection of the technical condition of vehicles in operation, and the effects of constant reforms on its performance. Based on the disadvantages identified, we substantiate the need and feasibility to implement continuous monitoring of the technical condition of vehicles. Using RTA statistics, we provide a rationale for parameters of such monitoring, which relate to the braking system and steering. Methods of their continuous monitoring are suggested. They do not require vehicle design alterations and imply the use of signals from on-board sensors. Results of the experimental testing of these methods are given.
The results of the research presented in this article characterize the influence of various factors on the current processes of the kinetic energy recovery system (KERS) for recovering kinetic energy of vehicles with electromechanical or electric drive (hybrid and electric cars) under braking. The article presents the basic limits of variations in accelerations and initial speeds during braking in urban traffic using WLTC (Worldwide harmonized Light-duty vehicles Test Cycles) as an example. Relationships affecting braking recovery are identified, which makes it possible to determine the power of the braking forces acting on a vehicle. Relationships between the initial braking speed, acceleration of deceleration, and recovery power are determined based on the relationships between the propulsion power and energy analysis. The resulting field of values for changes in regenerative braking power allows us to get an idea of the characteristics of KERS elements. The presented diagram describing changes in the maximum braking force power depending on the initial speed and acceleration of deceleration of a vehicle provides an insight into the possible ranges of the effective operation of the energy recovery system. As a result of a theoretical experiment, it was established that the vehicle mass affects the maximum power of regenerative braking. Based on the results of theoretical research, it is possible to determine the maximum current and power absorbed by an electric energy storage unit. The obtained relationship between the speed and acceleration in the process of active deceleration allows us to get an idea of the possible modes of charging the electric energy storage unit. Tests in road conditions, conducted with the use of several types of vehicles and test models with a hybrid engine, confirm the results of the research. The approaches presented in this article and the obtained results are indicative of the regularities of regenerative braking in vehicles operated in the road network, which makes it possible to select the optimal characteristics of an electric propulsion drive and ensure high fuel energy and environmental efficiency of vehicles at a minimum cost.
Road transport is one of the main sources of atmospheric pollution in urbanized areas. The volume of emissions from road transport has been increasing starting from 2013. This is mainly due to the condition of the transport infrastructure and control systems. Therefore, the development of evidence-based methods of increasing the efficiency of traffic management through the modernization of infrastructure facilities and control systems in problematic areas of the street and road network is crucial and of practical and theoretical interest. This paper analyzes problematic areas of the street and road network in a medium-sized city. The authors have made simulation models of an area of the street and road network on the basis of the discrete-event approach using a road traffic library. Measures to modernize this area are suggested. A computer experiment using a model with a changed configuration has shown that this area has a significant potential of improving traffic flow parameters and, therefore, reducing the environmental impact.
This paper analyzes the role and methods of diagnosing actor’s accident abilities, applied to traffic safety. We highlight the fact that safety equipment and measures (both industrial and traffic-related) provide only partial protection against various hazards, as the most critical hazard source for any person is the person themself, for a variety of reasons, including safety violations, which begin to occur when people grow accustomed to dangerous conditions and situations. By studying the internal (psychological) motivations behind reckless driving and other dangerous behavior, we gain additional opportunities for ensuring the safety of traffic and other high-risk activities. This paper analyzes studies by Russian and foreign authors that touched upon the factors of high-risk driving, and reviews the possible means of adjusting human behavior in dangerous situations by prompting a fear response. We also examine Russian researchers’ approaches to diagnosing accident abilities, which we define as the abilities to escape a dangerous situation safely; this includes having a sense of danger. We adopt S.A. Eliseev’s approach, wherein a person with a sense of danger is able to: balance between success and safety; avoid risks in conditions that they are accustomed to; not become accustomed to danger; find a safe approach to an unsafe situation; anticipate various actions and sources of danger; detect even subtle danger signs and warnings; learn from previous experiences with danger; predict and avoid danger. Our study includes several possible ways of diagnosing accident abilities: simulation experiments and surveys. We describe the process of designing and testing a survey form aimed at assessing a person’s sense of danger. The study includes a discussion of the future prospects of using this method.
The article addresses the issue of substantiating a methodological approach to evaluating the efficiency of automated information and telecommunication systems for vehicle traffic monitoring, which allows us to quantify the efficiency of their application. The feature of these systems is their service nature.
The authors develop a method for the optimal application of technical means of monitoring in the field of traffic safety assurance during the operation of the “driver–vehicle–road” system and obtain a dependence to determine the financial costs of maintaining the proper functioning of the photo and video recording complex throughout its service life. They propose criteria for evaluating the efficiency of automated vehicle traffic monitoring systems, taking into account the stochastic nature of system-forming factors. Promising directions for the formation of control functions in the operation of vehicles based on the use of automated monitoring systems are justified.
To evaluate the impact of the automated traffic enforcement system on traffic safety, it is necessary to conduct studies at two levels: at the first level, we shall give an absolute evaluation of the road accidents, at the second level, we shall analyze the influence of automated traffic enforcement systems on the number of road accidents by their location and types. The implementation of the “correlation recording system” allows assessing in practice the efficiency of use of various automated traffic enforcement facilities recording traffic violations, as well as the degree of their influence on the accident rates. The formulated scientific and technical task is solved with the use of methods and software tools implementing the systemic criterion.
The reliability and quality of the provided services may determine the level of performance and development in general. Many laws regulating the establishment of transport links are used in our country. The improvement of the legal and regulatory framework based on legal precedents is one of the key issues. It is necessary to take comprehensive measures to ensure safety. Many documents include the task of ensuring life safety and solving socio-economic issues as a key part. For example, Federal Law No. 196 “On Road Traffic Safety” dated December 10, 1995, which addresses the protection of the rights and interests of the society and state, the protection of life and health of citizens, and the prevention of road traffic accidents (RTAs), regulates the relations between car owners and the entire transport system as a whole. It is important to carry out preventive measures, which will result in a general decline in the accident rate on the roads of the Russian Federation. Traffic safety depends on many factors, where the competence and qualification of drivers, the condition of the road surface, as well as the technical condition of the vehicle in use are the main ones. The purpose of this study is to reduce annual accident rates, the number of fatalities and child injuries, which can be achieved by improving the skills of drivers, conducting multi-level knowledge tests, and making recommendations to be introduced in regulations.
When designing a wheeled vehicle, the designer’s task is to form its performance properties in various modes of movement. Due to the necessity to ensure maximum deceleration in given road conditions and, consequently, maximum (or relatively equal to maximum) braking forces on the wheels, the movement of a wheeled vehicle in the braking mode acquires a special status. It is known that such important performance properties of vehicles as braking dynamics, on the one hand, as well as stability and control, on the other hand, are in opposite conditions in terms of relative wheel slip. Thus, the improvement of some properties by changing the relative slip leads to the deterioration of others. Therefore, when forming the performance properties of vehicles in the braking mode, the designer faces the task of choosing a reasonable compromise, to achieve which it is usually necessary to sacrifice braking dynamics to ensure the required stability and control. The main task of forming performance properties is to determine to what extent this sacrifice will be justified (without maintaining stability, it makes no sense to talk about braking dynamics). Thus, due to the selection of the control structure on individual axles of a motor vehicle (especially for multi-axle cars and road trains), it is possible to ensure the required turnability and the formation of the performance properties in the braking mode, depending on the operating conditions and design of the motor vehicle (mainly, the speed range and layout features). Studies show that almost the same performance properties can be achieved with significantly fewer elements of an automated system, which certainly has an economic impact. This is particularly important for multi-axle cars and road trains. One of the tools for control structure analysis is virtual-physical modeling technology
The article analyzes the advantages and disadvantages of using gas engine fuel in automobile diesel engines (gas diesel engines). The global energy crisis has become a catalyst for the search for an alternative to diesel fuel. In the 1980s, experiments were carried out with regard to the operation of gas diesel vehicles. The results demonstrated a decrease in the efficiency of transportation, attracted criticism from car users, and were terminated. However, some countries continue to study gas diesel engines. The authors propose their own method of achieving positive results in the development and operation of gas diesel vehicles.
Our planet’s atmosphere is being contaminated by a variety of pollutants. Over a half of these hazardous chemicals is emitted by stationary industrial installations, while the rest come from operating motor-and-tractor and special-purpose machinery as well as vehicles. Around the globe, motor-and-tractor machinery emits millions of tons of oxocarbons, hydrocarbons, nitrogen oxides, and various compounds containing sulfur, soot, and other harmful substances. In response to this issue, most of the transportation in the Russian Federation is carried out by vehicles with diesel engines, which have greater energy conversion efficiency and consume 30% less fuel than vehicles with spark-ignition engines. Agricultural machinery, for the most part, is also powered by diesel fuel. The exhaust gases emitted by ICEs are a composite mixture of gases, vapors, liquid droplets, and dispersed solid particles. While possessing different chemical properties, the components of this mixture have a negative impact on human health, triggering allergies and causing severe diseases. Furthermore, environmental pollution by exhaust gases is detrimental to the output of agriculture and animal husbandry; it diminishes the quality of fodder plants and meat and dairy products, and reduces the value of horticultural crops. The ICE toxicity and smoke emission level depends on a number of factors, including the engine’s overall condition, the adjustment of the engine and fuel equipment, exhaust back pressure, manifold depression, and fuel quality. As the engine’s cylinder and piston group wears down during operation, the exhaust gases become contaminated with an increasing amount of incomplete combustion products; the share of crankcase fumes in the engine’s hazardous emissions increases as well. Most of the factors that have a negative impact on the ICE’s environmental safety during its operation can be eliminated through timely maintenance and regular repairs.
Keeping motor-and-tractor machinery in good condition is fundamental for reducing ICE toxicity during operation; however, it is far from the only requirement that needs to be met. Hazardous emissions and fuel consumption by motor-and-tractor machinery largely depends on compliance with the operational guidelines, including the proper use of high-quality fuels, oils, and other relevant supplies, such as fuel or oil additives.
This paper sets forth the findings of the research on the traffic accident rate in the constituent entities of the Russian Federation, based upon respective regional statistical data for the four-year period from 2015 to 2018. In order to achieve the goal of the research — to identify the main factors affecting the accident rate, — the methods of correlation and regression analysis were used. We obtained regression equations relating the main indicators of the accident rate to the most relevant factors. The quality of the regression equations is characterized by means of the coefficients of correlation between actual and estimated values of the number of RTAs (road traffic accidents), the number of RTA fatalities and injuries. We assessed the role of each factor under consideration by means of confidence estimates and confidence probabilities, and determined factors that have both a positive and a negative influence on the accident rate.
An innovative option for the development of the transport system of the Russian Federation is suggested, which provides for the establishment of an effective competitive transport system, based on the creation of high-performance safe vehicles and transport infrastructure. The presented characteristics of the age structure of the Russian fleet of vehicles indicate that they lag behind the current requirements for passive, active, post-accident, and environmental safety. In modern production and motor transport processes, new technologies are usually more fire-hazardous. One of the main indicators of passive fire safety is fire load, which determines the fire resistance limit of the structure and the requirements for fire protection systems. A block diagram for the fire hazard of cargo vehicles running on gas motor fuels is developed, which is based on fire load in cargo vehicles of category N2 running on compressed natural gas. The total thermal stress of the structure of cargo vehicles running on compressed natural gas is higher than that of gasoline and diesel vehicles by 5.6%. Full-scale tests of cargo vehicles running on gas motor fuels, using the method of creating an artificial fire seat, made it possible to solve issues of ensuring fire and explosion safety of vehicles by installing a bursting diaphragm on each high-pressure cylinder and using high-pressure cylinders made of alloy steel.
The creation of a digital twin requires appropriate content for a mathematical model of all the relevant processes and phenomena, correlating with the processes that occur within the real physical entities. A digital twin of a vehicle includes a model of the braking system, which is essential for ensuring safety. Modern automated braking systems are difficult to reproduce in a simulation, because of the sheer number of factors involved. Furthermore, there are additional processes that also have a substantial impact on both the system’s performance and the vehicle position in physical space. This paper covers the principles of applying a virtual and physical simulation technology to the production of a digital twin of active vehicle safety systems. We begin our study by analyzing the Vehicle–Driver–Road system and ranking its elements. Within the Vehicle system, in turn, we also build a hierarchy of the subsystems relevant to the simulation, ranking them by priority level. In the course of system analysis, we arrange all modules by priority, considering the traffic conditions. In the case of this particular study, we are dealing with the braking mode, and therefore give priority to the braking system module over the other subsystems and modules. We also suggest various ways of structuring the model of the braking system itself, depending on the task. The tasks are grouped by difficulty, in ascending order, from the task of designing an algorithm for controlling a single wheel to the task of controlling an entire automated braking system of a multi-wheel vehicle, across all possible automation levels (i.e. both the self-driving mode and the operation mode involving a real driver with unique physical and psychological characteristics). The virtual and physical simulation technology, as exemplified by the braking system, enables the improvement and adjustment of digital twins of both current and future vehicles.
The article addresses the environmental characteristics and factors of motor transport effects on the environment. The amount of harmful substances emitted by a vehicle into the atmosphere is affected by: speed and number of decelerations and accelerations; vehicle condition, quality of repair and maintenance; traffic intensity; climatic conditions in a specific area; and urban development rate. It is shown that the areas of focus in ensuring the environmental safety of motor transport are: limitation of fleet growth; intensive development of transport infrastructure; scientific traffic management; improvement of the environmental characteristics of vehicles; improvement of vehicle maintenance and repair quality; assurance of quality and improvement of automobile operating materials. The article also presents information on environmental exposure to operating materials of vehicles.
This paper describes the mechanism of the operating factors’ influence on the operating modes of the internal combustion engine (ICE) and the intensity of changes in the technical condition of its main interacting components. It considers changes in the physical and chemical properties of engine oil and its effect on the content of harmful substances in the exhaust gases of the internal combustion engine. The characteristic uprating of modern automobile diesel engines significantly worsens the operating conditions of both friction pairs and oil. Ensuring the reliable operation of such uprated engines is possible by improving the lubrication system and the quality of oils used. The performance properties of engine oils have a great influence on the efficiency of internal combustion engines and largely determine their reliability and durability as well as environmental impact. One of the important factors is the wear resistance of friction pairs, which directly depends on the metal-physical characteristics of the friction surfaces as well as the physical and chemical properties of engine oils, methods of their supply to friction units, and the design of the lubrication system. Based on studies conducted at the Yuri Gagarin State Technical University of Saratov we determined patterns of engine oil aging and its consumption, depending on operating factors, especially in uprated engines operating at maximum speeds and loads.
Introduction: This study proves that the procedure of inspecting road traffic accident black spots (RTA BS) needs improvement. This improvement is to involve the tools and insights associated with the targeted program approach, as well as a road infrastructure indicator system, and information technology tools. The creation of a road infrastructure indicator system and its comprehensive application, coupled with analytical methods and accident prediction system methods, enables the assessment of measures aimed at reducing the number of RTAs. Accounting for information technology tools and systems (such as the digital traffic safety inquiries desk) is also necessary if traffic safety is to be organized and maintained in a systemic way. Purpose of the study: The study is aimed at finding a new approach to improving the procedure of inspecting RTA black spots. Methods: In the course of the study, we use systemic analysis, analytical methods, traffic safety evaluation based on defining the safety and accident coefficients and revealing RTA black spots, probability theory methods, research results processing, and IT computational methods. Results: We provide a rationale for a comprehensive approach to inspecting RTA black spots within the “traffic participant – vehicle – road – external environment” system. We also demonstrate how a group of parameters can be used for studying the systemic indicators of road infrastructure, in the context of the parameters’ characteristics, as well as the conditions of their use. We determine the capabilities of analytical methods, as well as accident prediction methods, in the context of finding an approach to improving the procedure of inspecting RTA black spots. We propose applying a comprehensive approach to the improvement of the RTA BS inspection procedure.
Introduction of new technologies in cities through effective interaction between people and modern IT management tools has introduced the concept of «smart city» able to independently manage its own resources, energy, space and information to improve life quality. One of the main components of a «smart city» is «smart transport» using latest communication technologies for efficient movement, monitoring of location, interaction between vehicles and other traffic elements, general traffic safety improvement resulting in a decrease in the accident number (tendency towards zero mortality). One of the ways to expand this field of UAV application is their use for primary photofixation of the accident site, which will both increase the objectivity of the investigation and help to reduce time required for the investigation. Solving problems related to traffic safety in a «smart city» using IT technologies and UAVs — smart transport components results in fast collection of information, including that from hard-to-reach zones, the ability to take pictures from small heights and near objects to obtain high-resolution images. These are a possibility of application in emergency zones without unnecessary risk to life and health of personnel; improvement of the objectivity of primary information from the accident site; the possibility of automatic processing of the primary information with its transformation into the necessary types of formalized documents.
The present work introduces Stochastic Multicriteria Acceptability Analysis – Matching (SMAA-M), a MCDM technique which, just as former SMAA versions, has been designed for public decision environments. SMMA-M is specifically intended to support the choice for one or more alternatives among a finite set of them, when this decision is based on a theoretical model or reference system. The present version introduces the notion of value range of the decision alternatives, a mathematical concept that allows modelling the system. The decision process is supported on the degree of matching between the input and output states of the system. After featuring the system through criteria, the technique allows obtaining the set of weights that support each alternative's value range and favourable criterion weight indicators. In order to illustrate this new development, the present work searches for the governance forms that minimize the transaction costs of a supply chain's major echelon.
Thisarticle discusses the proposed method for diagnosing diesel fuel equipment. An analysis of available methods for diagnosing fuel equipment has been carried out. The authors describe their method for diagnosing plunger pairs of a high-pressure fuel pump according to the parameter of displacement of the injector needle. The design of the diagnostic device for measuring the movement of the injector needle has been developed and patented. The dependence of the maximum displacement of the injector needle on the increase, due to wear, of the radial clearance of the plunger bushing at the minimum steady state of idling of the engine has been determined. The technique of diagnosing the technical condition of plunger pairs of a high-pressure fuel pump by injector needle displacement is considered in detail.
Introduction: To study road infrastructure and ensure control over its changes during its use, it is required to
introduce a concept of indicator, which is a parameter or characteristic of road infrastructure facilities’ state. Studies on road infrastructure indicators are aimed at traffic safety increase, improvement of a system for road accident forecasting. The authors apply a system for the accounting of road infrastructure facilities’ characteristics, set during the design and construction of roads, to forecast road accidents. Purpose of the study: The authors develop an approach to studying the influence of systemic indicators of road infrastructure at accident clusters on traffic safety. Methods: During the study, such methods as system analysis, extrapolation method, method of forecasting with account for seasonality, and method of repetition were used. Results: The authors analyzed statistical data on the road accident rate and identified significant systemic indicators of road infrastructure to assess the efficiency of road and construction measures aimed at traffic safety assurance. They formed groups of indicators in the system of their parametric characteristics and determined conditions of their use to study systemic indicators of road infrastructure. They also determined the capabilities of methods used to forecast the road accident rate to develop an algorithm to analyze road infrastructure at accident clusters. The authors also developed such an algorithm to analyze road infrastructure at accident clusters.
The article discusses the problem of diagnosing diesel fuel equipment. The most common methods for diagnosing fuel equipment are presented. The rationale for diagnosing the technical condition of the plunger elements of the high pressure fuel pump by moving the injector needle is given.
The design of conservation management plans is a crucial task for ensuring the preservation of ecosystems. A conservation plan is typically embodied by two types of decisions: in which areas of a given territory it will be implemented, and how actions against threats will be deployed across these areas. These decisions are usually guided by the resulting ecological benefit, their spatial effectiveness, and their implementation cost.
In this paper, we propose a multi-criteria optimization framework, for modeling and solving a mixed integer programming characterization of a multi-action and multi-species conservation management design problem.
The optimization tool seeks for a management plan that maximizes ecological benefit and minimizes spatial fragmentation, simultaneously, while ensuring an implementation cost no greater than a given budget.
For showing the effectiveness of the methodology, we consider a case study corresponding to a portion of the Mitchell river catchment, located in northern Australia, where 31 freshwater fish species are affected by four threats.
The attained results show how the methodology exploits the trade-offs among the ecological, spatial and cost criteria, enabling decision-makers to explore and analyze a broad range of conservation plans. Selecting conservation plans in a more informed way allows to obtain the best outcomes from a strategic and operational point of view.
Crisis events every day endanger human society. New research in crisis management assume that number of crisis events will increase. It creates a new assumption to protect life, property, and the environment. Crisis management fulfills its roles in ever more complex conditions, nowadays. It is necessary to increase to use effectiveness crisis management. The efficiency of crisis management can use new integrating methods into management processes. In this article, multicriteria decision-making methods are used and compared by criteria, which was established. Based on this, may crisis management authorities choose the processes of crisis solution. Main goal of this contribution is application of decision-making methods, which may be used in evacuation process.
The article describes operating conditions of the railroad dowel used in ZhBR 65 resilient rail fasteners. Requirements for railroad dowel tests in terms of their expediency, possibility to perform such tests and conformity with the actual operating conditions are analyzed. The initiative of the authors, arisen during an analysis of regulatory documents, served as a basis for the studies. Stresses in a dowel and its safety factor in operation and tests were determined analytically by the finite element method, using the APM FEM library, the system of strength analysis for KOMPAS-3D, certified within the GOST-R system.
Railroad dowels manufactured by OOO NTT, ZAO Polimer ZAO and Vossloh Fastening Systems GmbH were used as study objects. For the purposes of simulation, 3D models of the corresponding dowels and their mating parts (sleeper, railroad screw, tension clamp, etc.) were built. According to the studies, in tensile tests of dowels, conducted according to Clause 4.6 of Specifications TsP 369 ТU-7, stresses of 85...100 MPa occur in the bodies of all dowels under consideration, which considerably exceed stresses appearing in dowels during operation, and the nature and distribution of such stresses do not correspond to those of operating stresses, the maximum value of which does not exceed 10 MPa.
The analysis of stresses arising in sleepers with dowels by the manufacturers under consideration has shown that their limit value is 75 MPa. Besides, in sleepers with dowels by OOO NTT and Vossloh Fastening Systems GmbH, the maximum stresses are in the sleeper body, which allows for their redistribution and prevents dowel pulling-out from a sleeper. Sleepers with dowels made by ZAO Polimer have maximum stresses in the upper face of a sleeper coaxially with the dowel axis, which significantly increases the probability of dowel pulling-out in case of extreme loads.
This article presents the process used to develop safety envelopes and subsea traffic rules for autonomous remotely operated vehicles (AROVs)used in subsea inspection, maintenance, and repair (IMR)operations. Preventing loss of subsea assets and the AROV is the overall goal of the proposed safety envelopes and subsea traffic rules. Currently, no such envelopes and rules exist. The safety envelope for the AROV is constructed using an Octree method. The proposed subsea traffic rules are derived by combining existing traffic regulations in marine and aviation industries. The proposed safety envelopes and traffic rules are tested using both a novel modular open robot simulation engine (MORSE)based underwater simulator and in the laboratory. The results from the laboratory tests show that the proposed safety envelopes and subsea traffic rules can be used during simulated or real IMR operations to recommend subsea traffic rules to the AROV and the human supervisor.
This study is concerned with a multiobjective allocation of resources (or their shortages), delivering an answer to the fundamental question “How to do?” arising in different types of planning activities (strategic, innovation, new business, research and development, expansion, operational, maintenance, etc. planning). The solution to the problem is associated with the extension of the general scheme of multicriteria decision making under uncertainty. This scheme is based on a possibilistic approach and involves a fuzzy set-based generalization of the classic approach to deal with the uncertainty to produce solutions, including robust solutions, in multicriteria analysis. Its usage, in the original form, helps one to use available quantitative information to the highest extent to reduce the decision uncertainty regions. If the quantitative information does not lead to a unique solution, the scheme presumes the application of information of qualitative character (based on knowledge, experience, and intuition of experts) used at the final decision stage. However, increasingly, we encounter problems whose essence requires the consideration of the objectives (investment attractiveness, political effect, maintenance flexibility, etc.) formed on the basis of qualitative information, at all decision process stages. Considering this, the study is aimed at generating multicriteria solutions, including multicriteria robust solutions, by constructing representative combinations of initial data, states of nature or scenarios with direct using qualitative information (with the possibility for experts to apply diverse preference formats processed by transformation functions) presented along with quantitative information, realizing a process of information fusion within the multiobjective models. The corresponding results are of a universal character and applicable to diverse classes of multiobjective problems. The paper also proposes a new approach to the homogeneous and expert-acceptable formulation of specific allocation objectives. Examples are presented to illustrate the study results.
During the recent years, car makers intensively develop and implement systems of active, passive, post-accident, environmental and fire safety of road vehicles. These devices and systems improve the safety but complicate the design and increase the cost of maintaining the vehicle in the operative condition. That is why there is necessity to evaluate the road vehicle as to the efficiency of operation regarding a number of complex safety characteristics. Solution to this task should be based on evaluating the (relative) importance of particular values for every characteristic considered to be a separate criterion of safety. In order to do that, we need to formulate a system of values for safety characteristics of the road vehicle and develop a formalized mechanism to assess the relative importance of every criterion in the form of a method for multi-criteria evaluation of the complex characteristic of road vehicle safety.
Traffic safety is a characteristic feature of road transport systems. It is regarded as a difficult challenge which requires a system approach to the management of the country’s road traffic system. Variability of the street and road network structure and its technical condition over time requires considering such functional features as complexity of the hierarchical structure of road transport systems and technologies exploited in them. The research identifies the factors which affect the functioning of automated traffic enforcement facilities and reviews issues of assessing their parameters affecting traffic safety in the Russian Federation. Therefore, groups of factors which affect the functioning of automated traffic enforcement facilities are identified and research stages are developed. Based on the data obtained, a mechanism for quantitative assessment of the functional efficiency of automated traffic enforcement systems is suggested to ensure traffic safety and management decision-making regarding reduction of the number of accidents in the street and road network. The obtained results related to the influence of automated traffic enforcement system parameters on traffic safety allowed revealing the relationship between those indicators and suggesting measures to improve traffic safety using automated traffic enforcement systems.
We introduce the notion of a maximum likelihood optimal decision alternative for the choice problem with a finite set of decision alternatives, assuming a general parametric preference model of the decision maker. We also develop an optimization-based method for the identification of such alternative for the cases in which the parametric preference model is based on uncertain intervals for criterion trade-offs. The suggested approach can be seen as generalising stochastic multicriteria acceptability analysis (SMAA) to a wider modelling setting. It also provides a maximum likelihood interpretation of the SMAA acceptability index.
We present and analyze several definitions of Pareto optimality for multicriteria optimization or decision problems with uncertainty primarily in their objective function values. In comparison to related notions of Pareto robustness, we first provide a full characterization of an alternative efficient set hierarchy that is based on six different ordering relations both with respect to the multiple objectives and a possibly finite, countably infinite or uncountable number of scenarios. We then establish several scalarization results for the generation of the corresponding efficient points using generalized weighted-sum and epsilon-constraint techniques. Finally, we leverage these scalarization results to also derive more general conditions for the existence of efficient points in each of the corresponding optimality classes, under suitable assumptions.
In China, it is more common for pedestrians than vehicles to disobey traffic signals, resulting in a high risk of pedestrian-vehicle accidents. Pedestrian waiting time are the most critical indicator of the tendency to violate traffic signals. A statistical analysis based on 4027 field-collected samples showed that the length of time that pedestrians are prepared to wait depends on the type of pedestrian traffic signal. Compared to a countdown-type signal, pedestrians were more likely to violate conventional-type signals. Furthermore, pedestrians were willing to wait longer during peak hours than during off-peak hours. There were no significant differences between the waiting times of male and female travelers. To predict pedestrian waiting time, we propose a generalized Pareto distribution (GPD) model and calibrated it based on our field data. Monte Carlo simulations showed that the maximum likelihood estimation (MLE), Bayesian MLE (BMLE), and weighted nonlinear least squares (WNLS) models are the best methods for estimating the scale and shape parameters of the GPD model. Several empirical results were output from the models. For example, at countdown-type signals, the 85th quantile of the tolerable waiting time in off-peak and peak hours was 51.5 and 54.4 s, respectively; the respective values for males and females were 55.4 and 55.0 s. At conventional signals, the tolerable waiting time was approximately 42.5 s. These findings are useful for the planning, design, and operation of pedestrian facilities.
Multidimensional knapsack problem (MKP) is a classic combinatorial optimization problem arising from many practical applications. To be closer to real-life applications, this paper focuses on a special kind of multi-objective MKP (MOMKP), where the optimization objectives are to maximize the total profit and minimize the maximum consumption of multidimensional resources. To solve it, a Pareto evolutionary algorithm based on Incremental Learning (PEAIL) is proposed, whose components mainly consist of two parts, i.e., the online Incremental Learning and the nondominated sorting. PEAIL is unique in that it can extract the historical information of the search behavior and then feed them back to the main evolutionary framework. Firstly, problem-dependent heuristics, including genetic operators and a repair mechanism for infeasible solutions, are proposed and discussed. Secondly, an online Incremental Learning approach is put forward to learn the probability model of excellent solutions during the iteration process. Thereby, we can predict promising individuals from this probability model, which are used for further strengthening PEAIL’s search ability. Thirdly, a simple yet effective competition-based improvement mechanism is proposed to refine the offspring of PEAIL. Finally, results of experiments on 45 benchmark instances and a real-life case study demonstrate the effectiveness and practical values of the proposed PEAIL.
This paper proposes a hybrid multiobjective evolutionary algorithm based on differential evolution (HMOEA/DE) to solve the flow shop scheduling problems (FSPs) with the criteria of minimizing the makespan and tardiness simultaneously. Firstly, the hybrid multiobjective evolutionary algorithm (HMOEA) in HMOEA/DE is designed as the global search strategy, which rapidly improves the convergence and distribution performances towards the center and edge regions of Pareto frontier. Secondly, differential evolution (DE) strategy is combined with HMOEA as the local search mechanism to further enhance the convergence and distribution performances on the elite population obtained by HMOEA. Two DE mutation operators are designed for the individuals in the elite population: one is to further improve the performance of each individual and the other serves to much enhance the individual randomly. Numerical comparisons indicate that the efficacy of HMOEA/DE outperforms the traditional multiobjective evolutionary algorithm without DE in convergence and distribution performances on benchmark test problems and FSPs while verifying the advantages and disadvantages of different DE methods.
Jointly optimizing maintenance and missions schedule for a vehicle has become a priority to improve the profitability for commercial heavy vehicles. Many research works are interested in optimizing either the preventive maintenance planning or the production planning but few researches are focused on scheduling both activities for a system which deteriorates over time. A static approach has previously been developed to jointly schedule missions and maintenance operations while considering the vehicle deterioration to minimize the maintenance costs. However, once the schedule is determined, no update is considered during its completion. This contribution presents a dynamic method to answer the joint scheduling problem based on the failure opportunities and the collected deterioration information. A comparison between the static and the dynamic approaches is drawn to evaluate the possible maintenance cost gain brought by the on-line information availability.