TO THE STABILITY OF TANK VEHICLES IN THE BRAKE MODE

2019 ◽  
pp. 27-32
Author(s):  
Denys Popelysh ◽  
Yurii Seluk ◽  
Sergyi Tomchuk
Keyword(s):  
Mathematical Model ◽  
Control Systems ◽  
Distribution Systems ◽  
Traffic Accidents ◽  
Road Traffic ◽  
Center Of Mass ◽  
Dynamic Processes ◽  
Course Stability ◽  
The Stability ◽  
Tank Vehicles

This article discusses the question of the possibility of improving the roll stability of partially filled tank vehicles while braking. We consider the dangers associated with partially filled tank vehicles. We give examples of the severe consequences of road traffic accidents that have occurred with tank vehicles carrying dangerous goods. We conducted an analysis of the dynamic processes of fluid flow in the tank and their influence on the basic parameters of the stability of vehicle. When transporting a partially filled tank due to the comparability of the mass of the empty tank with the mass of the fluid being transported, the dynamic qualities of the vehicle change so that they differ significantly from the dynamic characteristics of other vehicles. Due to large displacements of the center of mass of cargo in the tank there are additional loads that act vehicle and significantly reduce the course stability and the drivability. We consider the dynamics of liquid sloshing in moving containers, and give examples of building a mechanical model of an oscillating fluid in a tank and a mathematical model of a vehicle with a tank. We also considered the method of improving the vehicle’s stability, which is based on the prediction of the moment of action and the nature of the dynamic processes of liquid cargo and the implementation of preventive actions by executive mechanisms. Modern automated control systems (anti-lock brake system, anti-slip control systems, stabilization systems, braking forces distribution systems, floor level systems, etc.) use a certain list of elements for collecting necessary parameters and actuators for their work. This gives the ability to influence the course stability properties without interfering with the design of the vehicle only by making changes to the software of these systems. Keywords: tank vehicle, roll stability, mathematical model, vehicle control systems.

scholarly journals Mathematical model for estimation the stability of the vehicle's motion on overturning

2021 ◽  
pp. 47-52
Author(s):  
Serhii Povaliaiev ◽  
Olexii Saraiev
Keyword(s):  
Mathematical Model ◽  
Traffic Accidents ◽  
Order Differential Equation ◽  
Road Traffic ◽  
Center Of Mass ◽  
Conservation Of Energy ◽  
The Stability ◽  
The Moment ◽  
The Mathematical Model ◽  
Vehicle Movement

Problem. During the reconstruction of the circumstances of road traffic accidents with vehicles overturning, difficulties arise with determining the parameters of vehicles in the process of their overturning. This is due to the fact that the recommended calculation methods are often simplified. The main focus of such techniques is to determine the minimum speed of vehicles, which leads to their overturning. In fact, the speed of vehicles before overturning can be significantly higher. Goal. This paper is dedicated to developing mathematical model of overturning vehicles that makes possible to determine not only the conditions for overturning vehicles, but also other parameters of the vehicle movement in the process of overturning. Methodology. The overturning of the vehicle occurs as a result of the action of inertial forces after collision with an immovable side obstacle. In this case, the moment from the force of gravity of the vehicle keeps it from overturning. In the process of overturning the vehicle, the moment from the force of gravity decreases due to the decrease in the arm of the force of gravity. To compile a mathematical model, the basic equation of dynamics during rotational motion was used. The mathematical model of a vehicle overturning is written in the form of a nonlinear homogeneous second order differential equation. An analytical solution of this equation is obtained. Results. Developed mathematical model makes possible to determine not only the conditions for overturning vehicles, but also other parameters of the vehicle movement from the moment the center of mass begins to rise to the moment of its maximum rise in the process of overturning. For a particular case, when the critical speed of a vehicle during its overturning is determined, the developed mathematical model fully corresponds to the mathematical model based on the law of conservation of energy. For a specific vehicle, numerical results were obtained that fully correspond to the physics of the overturning process.

scholarly journals MODELING OF THE MECHANISM OF VEHICLE OVERTURNING IN THE PROCESS OF DEVELOPMENT OF ROAD TRAFFIC ACCIDENT

2019 ◽  
Vol 20 (2) ◽  
pp. 320-328
Author(s):  
S. Povalyaev ◽  
O. Saraiev
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Critical Speed ◽  
Traffic Accidents ◽  
Road Traffic ◽  
Center Of Mass ◽  
Road Traffic Accidents ◽  
Basic Parameters ◽  
The Moment ◽  
Comparison Of The Results

The development of mathematical models of vehicle overturning has been given significant attention by many researchers because of the need to obtain reliable information on the circumstances of road traffic accidents. Research of road traffic accidents with the overturning of vehicles is related with the difficulty to determinate the mechanism of overturning, because expert calculation methods do not always use the adapted mathematical models. Most of the methods focus on determining the minimum (critical) speed of vehicles, which leads to its overturning. However, the real speed of vehicles before overturning can be much higher. In this paper, a mathematical model of the process of vehicle overturning after a collision with an immovable lateral obstacle is given. Thus the overturning moment caused by the inertia forces acts on the vehicle, and the moment from the gravity that holds the vehicle from overturning. It is necessary to mark that the shoulder of moment from gravity changes from a maximal value to 0 in the process of vehicle overturning. The mathematical model is based on the basic equation of dynamics for rotational motion. The developed mathematical model is a nonlinear homogeneous differential equation of second order. A solution of this equation is obtained that allows us to determine the conditions for the vehicles overturning and to investigate the basic parameters of the movement of vehicles in the process of overturning from the moment when the center of mass of the vehicle begins to rise until the moment of its maximum lifting. A comparison of the results of calculating the critical speed of vehicles with results obtained on the basis of the law of energy conservation was carried out. The results are fully agreed. The numerical results obtained using a mathematical model for a particular vehicle have been analyzed.

scholarly journals Analysis of Platform Leveling Systems for Tracked Feller-Buncher Machines

Inventions ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 96
Author(s):  
Andronov Alexandr ◽  
Bacherikov Ivan ◽  
Zverev Igor
Keyword(s):  
Mathematical Model ◽  
Center Of Mass ◽  
Slope Angle ◽  
Hydraulic Cylinder ◽  
Second Stage ◽  
Modeling Methods ◽  
The Third ◽  
Support Reaction ◽  
Third Stage ◽  
The Stability

The study was devoted to the analysis of feller buncher platform leveling systems. The widespread use of these systems in the design of modern feller-buncher machines makes the study relevant to assess operational efficiency. The analysis was conducted in five stages using analytical and stochastic mathematical modeling methods. In the first stage, the existing layouts of alignment systems were analyzed from the position of force on the hydraulic cylinder rods of the platform tilt drive. The three-cylinder layout scheme, where the force on the hydraulic cylinder rod was 50…60% less than that on the two-cylinder layout, appeared to be the most expedient. In the second stage, a mathematical model for determining changes in the position of the center of mass of the feller-buncher depending on the inclination angle of the platform was derived. In the third stage, a mathematical model was derived for determining the limiting angle of slope of the terrain when the feller buncher moved up the slope. For this purpose, two calculation schemes were considered when the machine moved up the slope without and with a tilted platform. Zero support reaction on the front roller was taken as the stability criterion. In the fourth stage, a mathematical model for determining the limiting angle of slope of the terrain during the roll of the feller-buncher machine was obtained. In the fifth stage, the efficiency of the application of leveling systems was evaluated. A graph of the dependence of changes in the terrain slope angle on the platform slope angle was plotted, and a regression dependence for an approximate estimate was obtained. A regression analysis was also carried out, and dependencies were obtained to determine the weight of a feller-buncher with a leveling system and the added pressure on the ground caused by the increase in the weight of the base machine. The analysis of platform leveling systems showed the effectiveness of their application in the designs of feller-buncher machines, as it allows the machines to work on slopes with an inclination of 50…60% more than without them.

scholarly journals RELIABILITY CRITERION AND A MODEL FOR DETERMINING THE OPTIMAL SPEED OF MOVEMENT ON AUTOMOBILE ROADS IN WINTER SLIDING CONDITIONS

2020 ◽  
Vol 6 (444) ◽  
pp. 119-125
Author(s):  
D. E. Yessentay ◽  
◽  
A. K. Kiyalbaev ◽  
S. N. Kiyalbay ◽  
N. V. Borisуuk ◽  
...  
Keyword(s):  
Traffic Accidents ◽  
Road Traffic ◽  
Rolling Resistance ◽  
Main Criterion ◽  
The Road ◽  
Optimal Speed ◽  
Road Surfaces ◽  
Braking Distance ◽  
Effective Decision ◽  
The Stability

The article presents a model for establishing the optimal speed of movement on highways, taking into account the determination of the braking distance in winter slippery conditions. According to the research results, it was established that the main criterion for the formation of road accidents on highways in winter slippery conditions is the drivers' underestimation of the adhesion qualities of road surfaces. The main criterion of the model under consideration is the interaction of the car wheel (braking distance) with the road (adhesion coefficient) and is a complex that characterizes the stability of the car rolling over on slippery surfaces and the driver's actions in making an effective decision and the duration of the reaction time. In the proposed mathematical model, the accident rate on a slippery road is estimated by the coefficient of adhesion of icy road surfaces, the value of the load or the average wheel pressure. Also, the frequency of load application, the amount of deflection of the coating (at an air temperature above +20 ° C), rolling resistance, the coefficient of adhesion of the car wheel to the coating. One of the main characteristics of the model is a subsystem - the average pressure p = Q / S (S is the area of the imprint of the wheel, cm²), etc. Thus, in the process of analyzing the results of the causes of road traffic accidents, the factors of the driver's reliability and the decisions made will be taken into account, which depend on the speed of vehicles in any condition of the road surface.

scholarly journals ABOUT THE INFLUENCE OF VIBRATIONS OF THE CONVEYED LIQUID ON THE AREA OF STABILITY OF A CLOSED SYSTEM AUTOMATIC VEHICLE COURSE CONTROL

2021 ◽  
pp. 29-41
Author(s):  
Yevgen Aleksandrov ◽  
Tetyana Aleksandrova ◽  
Alexander Grigoriev ◽  
Yaroslav Morhun
Keyword(s):  
Mathematical Model ◽  
Free Surface ◽  
Pid Controller ◽  
Low Frequency ◽  
Forced Oscillations ◽  
Liquid Lead ◽  
Variable Parameters ◽  
Course Stability ◽  
The Stability ◽  
Stability Area

The existing publications that investigate vehicle course stability optimization were analyzed. A mathematical model, which describes the disturbed movement of a car with a tank, was compiled. This model allows to consider the liquid free surface oscillations and determine their effect on the car course stability during constant motion or emergency braking. There was described the main information regarding the car that was used to perform mathematical calculations. An algorithm was developed for deriving the characteristic equation for a complex system of differential equations describing dynamic changes in the movement parameters of a car, oscillations of partial layers of liquid in a tank and the operation of an electromagnetic drive of the control valve and an electronic PID controller for a two-circuit system for ensuring course stability. Based on the developed mathematical model, the influence of forced oscillations of the fluid on the stability area of the system built in the plane of variable parameters of the controller is investigated. It is shown that low-frequency oscillations of the free surface of a liquid lead to a significant reduction in the stability area, which indicates the need to consider such oscillations when solving problems of analysis and synthesis of this system. It was found that for a car with a tank, where low-frequency transverse oscillations of the liquid occur, which are accompanied by a redistribution of mass and disturb the movement, an increase of the speed unambiguously leads to a deterioration in directional stability. That enables exclusion of speed from the number of variable parameters and significantly simplify the problem being solved. The calculations for cases with different loading levels were performed. It was found out that the level of liquid in the tank, considering its relationship with the speed, has an ambiguous effect on the car course stability, and it is unacceptable to limit the research calculations to the case with 50 % load. Instead of this, it is necessary to find a line that bends from above the stability boundaries that correspond to many liquid levels. Keywords: fluid vibrations; exchange rate stability system; area of stability; tank; PID-controller; parameters.

scholarly journals Mathematical model of road traffic accident development using the system analysis theory

2021 ◽  
pp. 136-143
Author(s):  
Alexander Gusev ◽  
◽  
Innesa Rutkovskaya ◽  
Alla Gerasimenko ◽  
◽  
...  
Keyword(s):  
System Theory ◽  
Mathematical Model ◽  
Road Traffic Accident ◽  
Traffic Accident ◽  
Traffic Accidents ◽  
System Analysis ◽  
Road Traffic ◽  
Road Traffic Accidents ◽  
The Road ◽  
Analysis Theory

The article describes the principles and algorithms for creating a mathematical model of the road traffic accidents on the highway section using system analysis theory and queuing system theory.

scholarly journals Step-by-step analytical synthesis of the mathematical model of automotive unmanned aircraft

2021 ◽  
pp. 21-28
Author(s):  
A. A. Lobaty ◽  
A. Y. Bumai ◽  
S. S. Prohorovith
Keyword(s):  
Mathematical Model ◽  
Center Of Mass ◽  
Aerodynamic Characteristics ◽  
Unmanned Aircraft ◽  
Control Synthesis ◽  
Aerial Vehicle ◽  
Stage Synthesis ◽  
The Stability ◽  
The Mathematical Model ◽  
Analytical Synthesis

The problem of the stage-by-stage synthesis of the mathematical model of the autopilot of an unmanned aerial vehicle (UAV) is considered. At the first stage, an analytical synthesis of the control acceleration applied to the center of mass of the UAV is performed to form a specified trajectory of its flight. On the basis of the results received at the first stage, at the subsequent stages, the problem of synthesizing a mathematical model of the UAV autopilot is solved with the specified requirements for ensuring the stability and dynamic accuracy of UAV control. Under actual assumptions about the corresponding nature of changes in the trajectory parameters and variables that characterize the motion of the UAV in space, the use of a linear mathematical model of the evolution of the state vector of the UAV and its control system is substantiated. When synthesizing a mathematical model of the UAV autopilot, the method of modal control of the system was used for a specified mathematical model of the object. For a specified model of motion and aerodynamic characteristics of the UAV, the law of deviation of the control steering surface is analytically received, which depends on the parameters of the translational and rotational movement of the UAV. Computer simulation of the analytically received results of control synthesis for the specified characteristics of UAVs and specific using conditions was carried out, which clearly showed the efficiency and prospects of using this approach for the synthesis of control systems for UAVs of various purposes and design.

scholarly journals Ensuring the Stability of Agricultural Transport and Technological Machines Equipped with Ultra-Low Pressure Tires during Braking

2020 ◽  
Vol 30 (4) ◽  
pp. 609-623
Author(s):  
Umar Sh. Vakhidov ◽  
Andrey A. Kurkin ◽  
Lev S. Levshunov ◽  
Iuri I. Molev ◽  
Dmitriy N. Proshin ◽  
...  
Keyword(s):  
Traffic Safety ◽  
Road Traffic ◽  
Center Of Mass ◽  
Low Pressure ◽  
Front Axle ◽  
Road Surface ◽  
Emergency Braking ◽  
Road Traffic Safety ◽  
The Stability ◽  
Agricultural Machines

Introduction. Improving the efficiency of agricultural operations and off-road logistics require new highly efficient non-road machinery with low pressure on road surface. The versatility of the use of this machinery imposes additional requirements on its design, including those related to road traffic safety on public roads. Changes in brake design are required to ensure safe braking performance when larger diameter wheels are used for the reason that to produce standard braking force according to the technical regulations for the safety of wheeled vehicles, requires more braking torque when using larger diameter wheels. Materials and Methods. The article proposes a model for calculating the braking parameters of transport and technological agricultural machines equipped with ultra-low pressure wheels. The model differs from those used earlier in that its output parameter is not the braking efficiency, but the time difference between the front and rear axle locks. Results. Fulfilling the condition of the front axle advance locking ensures the stability of the tractor motion during emergency braking that has a positive effect on road traffic safety. The results of the study suggest that to ensure the safe motion of the machines equipped with ultra-low pressure tires on public roads, it is necessary that the ratio of the distance from the center of mass to the front axle is at least not less than the distance from the center of mass to the road surface. Discussion and Conclusion. The proposed mathematical model has shown its adequacy. The obtained mathematical dependencies allow us to justify different technical solutions for ensuring safe road movement of transport and technological agricultural machines equipped with ultra-low pressure tires. Thus, the maximum permissible height of the center of mass can be assumed to be equal to 90% of the distance from the location of the center of mass of an agricultural transport and technological machine to its front (controlled) axis.

scholarly journals Usage of SUMO Computer Modeling Software for Road Traffic Control System Validation

2019 ◽  
Vol 8 (2) ◽  
pp. 4662-4666
Keyword(s):  
Control System ◽  
Computer Modeling ◽  
Control Systems ◽  
Traffic Control ◽  
Road Network ◽  
Traffic Accidents ◽  
Road Traffic ◽  
Control Logic ◽  
Modeling Software ◽  
Traffic Control System

Modern road traffic control systems become more complex with each year due to the growing number of cars, demand for more optimized road network designs, and desire to decrease road traffic delays at the intersections during rush hours because of the constantly growing metropolitan area and hence the need of moving farther away across the city. Therefore, a need is very much relevant nowadays for technologies, which can help build more optimal and intelligent road traffic control systems, which in turn will help optimize already existing road network designs. With the help of computer modeling software, it is possible to recreate already existing segments of road network, and by implementing control logic, it is possible to observe how control system and road traffic would react to various changes. This paper looks at how computer modeling software (namely SUMO) can help with the validation of road traffic control system changes without the risks of road traffic accidents caused by manipulation of real control systems.

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