Reduction of energy losses on car movement while using a combined electromechanical drive of leading wheels

This article addresses the problem that fluctuations in the torque of an internal combustion engine (ICE) lead to additional energy losses, as it causes fluctuations in the speed and kinetic energy of the car. These losses increase as the frequency of oscillations of the torque of the internal combustion engine approaches the frequency of free (natural oscillations) of the running gear of the car in the longitudinal direction. If there is an elastic connection between the traction force and the movement of the car, the movement of the latter can be represented as complex. At the same time, the portable movement is uniform, and the relative movement is oscillatory. This article presents the results of the study of these losses for cars with mechanical and combined electromechanical drive wheels. Analytical expressions are obtained, which allows to take into account additional energy losses including the tangential rigidity of the tire and the rigidity of the suspension in the longitudinal direction. When using a combined electromechanical drive of the drive wheels as well as in the case of a mechanical transmission of a car, the resonance is dangerous. But with the increase in the share of torque kem on the wheel generated by the electric motor, the relative additional energy losses for the movement of the car are reduced

Improvement of the method for assessing the energy load of vehicle

The aim of the research is to improve the indicators assessment accuracy of the vehicle energy load by improving the method of experimentally - theoretical determination of the aerodynamic drag parameters of vehicle in motion. To achieve this goal, it is necessary to solve the problem of determining the dependence of the energy load level on vehicle speed with varying frontal aerodynamic drag coefficient. Studies carried out to clarify the calculation of the parameters of vehicle aerodynamic drag in motion made it possible to determine the correlation between the actual effective engine capacity and the maximum kinetic energy of vehicle at translational motion. When determining the vehicle aerodynamic drag, the constant coefficient of aerodynamic drag is used depending on the speed in all range of vehicle speeds. This leads to significant mistakes in determining the necessary engine capacity expendable to overcome the aerodynamic drag, and vehicle fuel consumption. As a result of the research, analytical expressions, allowing to take into account additional energy losses and correlation between the kinetic energy of the vehicle steady motion and the effective engine capacity have been obtained. The theoretical contribution of the research is that the correlation coefficient between the kinetic energy of vehicle in motion and the effective engine capacity – have been proposed. Studies have shown that if speed of vehicle increases the indicator will monotonously decrease in the range of actual speeds

Синтез енергоефективного закону управління розгоном автомобіля

We have established the laws of change in the vehicle acceleration time at the existing step transmission of ICE, when implementing the total traction force, boundary for the drive wheels adhesion to the road, and during implementation of the proposed rational law for acceleration control. To model ICE speed characteristics, we applied the empirical dependence by S.R. Leyderman. The analytical expressions obtained allow us to implement such a change in vehicle acceleration depending on its speed that makes it possible to ensure maximum dynamism at minimal engine power consumption, taking into consideration a nonlinear change in external resistance. The maximum acceleration, which is possible to implement using the rational dynamic characteristic, can reach 7 m/s2. Based on the dependences obtained, it is possible to determine effective work of ICE required to accelerate a vehicle at different gears. An analysis of calculation results revealed that the transition from lower to higher gears is accompanied by a sharp decrease in engine energy expenditure required to accelerate the vehicle.It was established that for the case of hybrid vehicles, acceleration using the electric drive, rather than accelerating at lower gears of the mechanical drive, makes it possible to reduce energy losses by 20 % (for a four-cylinder internal combustion engine). Energy preservation is accomplished by reducing the fluctuation of traction force, as well as the possibility of a step-free change in motion speed.Определена рациональная динамическая характеристика автомобиля, позволяющая разгон при минимальных затратах энергии двигателя. Определены законы изменения времени разгона автомобиля при реализации предельной по сцеплению ведущих колес с дорогой суммарной тяговой силы и при реализации предложенного рационального закона управления ускорением. Проведена оценка эффективной работы ДВС при разгоне на различных передачах автомобиляВизначена раціональна динамічна характеристика автомобіля, що дозволяє розгін при мінімальних витратах енергії двигуна. Визначено закони зміни часу розгону автомобіля при реалізації граничної по зчепленню ведучих коліс з дорогою сумарної тягової сили й при реалізації запропонованого раціонального закону управління прискоренням. Проведена оцінка ефективної роботи ДВЗ при розгоні на різних передачах автомобіл

Синтез енергоефективного закону управління розгоном автомобіля

We have established the laws of change in the vehicle acceleration time at the existing step transmission of ICE, when implementing the total traction force, boundary for the drive wheels adhesion to the road, and during implementation of the proposed rational law for acceleration control. To model ICE speed characteristics, we applied the empirical dependence by S.R. Leyderman. The analytical expressions obtained allow us to implement such a change in vehicle acceleration depending on its speed that makes it possible to ensure maximum dynamism at minimal engine power consumption, taking into consideration a nonlinear change in external resistance. The maximum acceleration, which is possible to implement using the rational dynamic characteristic, can reach 7 m/s2. Based on the dependences obtained, it is possible to determine effective work of ICE required to accelerate a vehicle at different gears. An analysis of calculation results revealed that the transition from lower to higher gears is accompanied by a sharp decrease in engine energy expenditure required to accelerate the vehicle.It was established that for the case of hybrid vehicles, acceleration using the electric drive, rather than accelerating at lower gears of the mechanical drive, makes it possible to reduce energy losses by 20 % (for a four-cylinder internal combustion engine). Energy preservation is accomplished by reducing the fluctuation of traction force, as well as the possibility of a step-free change in motion speed.Определена рациональная динамическая характеристика автомобиля, позволяющая разгон при минимальных затратах энергии двигателя. Определены законы изменения времени разгона автомобиля при реализации предельной по сцеплению ведущих колес с дорогой суммарной тяговой силы и при реализации предложенного рационального закона управления ускорением. Проведена оценка эффективной работы ДВС при разгоне на различных передачах автомобиляВизначена раціональна динамічна характеристика автомобіля, що дозволяє розгін при мінімальних витратах енергії двигуна. Визначено закони зміни часу розгону автомобіля при реалізації граничної по зчепленню ведучих коліс з дорогою сумарної тягової сили й при реалізації запропонованого раціонального закону управління прискоренням. Проведена оцінка ефективної роботи ДВЗ при розгоні на різних передачах автомобіл

Improving the maneuverability of vehicles by using front swivel axles with separate electric wheels

There is a need for vehicles to maneuver when there are traffic jams, to overcome narrow streets and various obstacles. This leads to increased requirements for dynamism and maneuverability of vehicles. The authors present the results of the development and research of the steering control of the vehicle, which provides increased maneuverability. Such circumstances significantly affect the increase in maneuverability of wheeled vehicles, including tractors, for which the use of front suspension axles is possible in terms of layout. The use of a front swing axle with electric motor-wheels with separate control will increase the maneuverability of a two-axle vehicle and minimize the steering effort when turning. When solving the task, a mathematical model of the movement of the vehicle on a turn was created. The forces in the contact of the wheels with the road surface were determined, which made it possible to determine the forces and moments of resistance to the rotation of the front axle. Rational laws of control of turning the front axle, providing minimal resistance to the movement of the vehicle, were obtained. A vehicle turning control option is proposed, in which the wheels of the outer and inner sides are alternately braked when the vehicle enters and exits the turn. In addition, it is possible to alternately create a torque difference on the wheels of the outer and inner sides of the front axle. Using the proposed turn control options, it is possible to create a multi-axle vehicle with a rocking axle. The materials of the article on the controllability of vehicles depending on the design of the steering and front axle are of interest to researchers, designers of mobile equipment, graduate students and students of engineering specialtie

ДИНАМІКА АВТОМОБІЛЯ З АВТОМАТИЧНОЮ БЕЗСТУПІНЧАСТОЮ КОРОБКОЮ ПЕРЕДАЧ

Abstract. Problem. A significant amount of research has been devoted to the dynamics of car acceleration. They determined the maximum dynamic performance of a car due to the adhesion of the wheels and the supporting surface; analytical dependencies were obtained connecting the maximum possible acceleration, the minimum time and the acceleration path with the vehicle speed; the considered issues associated with the use of combined power plants, etc. However, these studies almost did not consider the option of controlling the car acceleration using a continuously variable gearbox. Goal. The aim of this research is the improvement of dynamic properties and energy efficiency of cars through the implementation of rational laws of changing the gear ratio of a continuously variable gearbox at a constant speed. Methodology. The use of continuously variable gearbox can improve the performance of the dynamic properties and energy performance of vehicles. When the engine is running at a constant speed the acceleration of the car will be an infinitely variable reduction gear ratio of the transmission range from the maximum to the minimum value. Saving energy is realized by provision of optimal car running, as well as by the exclusion of costs for the acceleration of the rotating masses when shifting and the change in angular velocity of the crankshaft. Results. The work investigated the possibility of controlling the acceleration of a car with a stepless change in the transmission ratio and engine operation at a constant crankshaft rotation speed. At the same time the effective mode of constant engine power, and the mode of change of the engine output according to a linear law were also considered. Originality. As a result of this research, we developed dynamic mathematical models of the acceleration of a car with a continuously variable gearbox at a constant angular velocity of the crankshaft. Calculated dependencies have been obtained that allow assessing the impact of the design and operational parameters of a vehicle and its engine-transmission unit on the acceleration dynamics. The functions of rational change in the gear ratio of a continuously variable transmission have been determined and recommendations have been formulated to improve the dynamic and economic performance of the vehicle. Practical value. This article is devoted to the analysis of the car dynamics acceleration and is aimed at improving its dynamic characteristics and energy efficiency. The obtained results can be used in the design and research of engine-transmission systems with internal combustion engines.Аннотация. В работе исследуется динамика разгона автомобиля, оборудованного бесступенчатой автоматической коробкой передач и двигателем внутреннего сгорания, который работает на постоянном скоростном режиме. Получены расчетные зависимости, позволяющие количествено оценить влияние параметров автомобиля на динамику его разгона. Сформулированы рекомендации по улучшению динамических свойств и энергетической экономичности автомобилей.Анотація. У роботі досліджується динаміка розганяння автомобіля, обладнаного безступінчастою автоматичною коробкою передач і двигуном внутрішнього згоряння, що працює на постійному швидкісному режимі. Отримано розрахункові залежності, які дозволяють кількісно оцінити вплив параметрів автомобіля на динаміку його розганяння. Сформульовано рекомендації щодо поліпшення енергетичної економічності й динамічних властивосте автомобілів

Analyzing the dynamics of a single car wheel

The paper presents an analytical solution to the equation of dynamic energy spending for rectilinear uniform rousset of a drive wheel with an elastic tire when driving on a solid support surface. To that end, the paper proposes different initial calculation charts to analyze the dynamics of the drive wheel; it also finds the efficiency and the additional energy spending in wheel rousset

Analyzing the dynamics of a single car wheel

The paper presents an analytical solution to the equation of dynamic energy spending for rectilinear uniform rousset of a drive wheel with an elastic tire when driving on a solid support surface. To that end, the paper proposes different initial calculation charts to analyze the dynamics of the drive wheel; it also finds the efficiency and the additional energy spending in wheel rousset