Моделювання робочих процесів двигуна автогрейдера при роботі при несталому навантаженні

We proposed a model of operation processes of a motor grader engine under unsteady load during technological processes of road construction works. Theoretic dependences of operation processes of a diesel motor grader engine, described by third order differential equations, were determined. The developed mathematical model of operation processes of a motor grader engine under unsteady mode makes it possible to employ known theoretical provisions to improve the system of air regulation in the commercially available motor grader engines. The model is a description of patterns of influence of differential equations coefficients and the load character on a change in the rotation rate of crankshaft of engine, cyclic fuel supply and hourly fuel consumption. Numerical modeling was carried out of load throw off and load gain of a motor grader engine using third-order differential equations in relative magnitudes. It was established that at a decrease in the values of coefficients of differential equation the transition process proceeds more intensively. In this case, time of delay in the response to disturbance and the duration of damping the oscillation process decrease. The proposed model would ultimately optimize engine performance under unsteady modes.Предложена модель рабочих процессов двигателя автогрейдера при неустановившейся нагрузке в технологических процессах дорожно-строительных работ. Определены теоретические зависимости работы двигателя автогрейдера. Установлены закономерности влияния характера нагрузки на изменение частоты вращения коленчатого вала двигателя, цикловой подачи топлива и часового расхода топлива. Предложенные зависимости позволяют оптимизировать работу двигателя в неустановившихся режимахЗапропоновано модель робочих процесів двигуна автогрейдера при несталому навантаженні в технологічних процесах дорожньо-будівельних робіт. Визначені теоретичні залежності роботи двигуна автогрейдера. Встановлено закономірності впливу характеру навантаження на зміну частоти обертання колінчастого валу двигуна, циклової подачі палива і годинної витрати палива. Запропоновані залежності дозволяють оптимізувати роботу двигуна в несталих режима

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

Розробка методу оцінки керованості автомобіля за коефіціентом динамічності

The study has explored one of the most important performance properties of the vehicle, which determines road traffic safety, – control in a steady mode. A method has been suggested for evaluating the stability of a vehicle against yaw with regard to the dynamic factor. We have found a dependence of the dynamic factor on the design and operational parameters of the vehicle. The dynamic factor can be reduced through achieving a neutral steering of the vehicle by controlling the ratio of the total lateral rigidity of the tires of the front and rear wheels. It has been determined that a change in the tire air pressure, measured by the developed algorithm, improves vehicle stability against yawing and thus contributes to traffic safety. In the example of the truck Ural-4320, the suggested method was used to determine the total lateral stiffness of the wheels under the condition of ensuring the vehicle’s neutral steering. The study has revealed that in the case of an equipped vehicle it is necessary to reduce the tire pressure in the wheels on the equalizer trolley in correlation to the air pressure in the tires of the front wheels. The research results can be used both in operating the existing vehicles and for designing new ones.Предложен метод оценки управляемости автомобиля в установившемся режиме движения с помощью коэффициента динамичности. Определено, что изменение давления воздуха в шинах, с использованием разработанного алгоритма, позволяет повысить устойчивость автомобиля против рыскания и, соответственно, безопасность дорожного движения. Полученные результаты могут быть использованы как в процессе эксплуатации, так и при проектировании новых конструкций машин.Запропоновано метод оцінки керованості автомобіля у сталому режимі руху за допомогою коефіцієнта динамічності. Визначено, що зміна тиску повітря в шинах, з використанням розробленого алгоритму, дозволяє підвищити стійкість автомобіля проти рискання і, відповідно, безпеку дорожнього руху. Отримані результати можуть бути використані як в процесі експлуатації, так і при проектуванні нових конструкцій машин.

Modeling of Operation Processes of a Motor Grader Engine During Work Under Unsteady Load

We proposed a model of operation processes of a motor grader engine under unsteady load during technological processes of road construction works. Theoretic dependences of operation processes of a diesel motor grader engine, described by third order differential equations, were determined. The developed mathematical model of operation processes of a motor grader engine under unsteady mode makes it possible to employ known theoretical provisions to improve the system of air regulation in the commercially available motor grader engines. The model is a description of patterns of influence of differential equations coefficients and the load character on a change in the rotation rate of crankshaft of engine, cyclic fuel supply and hourly fuel consumption. Numerical modeling was carried out of load throw off and load gain of a motor grader engine using third-order differential equations in relative magnitudes. It was established that at a decrease in the values of coefficients of differential equation the transition process proceeds more intensively. In this case, time of delay in the response to disturbance and the duration of damping the oscillation process decrease. The proposed model would ultimately optimize engine performance under unsteady modes

A Method of Evaluating Vehicle Controllability According to the Dynamic Factor

The study has explored one of the most important performance properties of the vehicle, which determines road traffic safety, – control in a steady mode. A method has been suggested for evaluating the stability of a vehicle against yaw with regard to the dynamic factor. We have found a dependence of the dynamic factor on the design and operational parameters of the vehicle. The dynamic factor can be reduced through achieving a neutral steering of the vehicle by controlling the ratio of the total lateral rigidity of the tires of the front and rear wheels. It has been determined that a change in the tire air pressure, measured by the developed algorithm, improves vehicle stability against yawing and thus contributes to traffic safety. In the example of the truck Ural-4320, the suggested method was used to determine the total lateral stiffness of the wheels under the condition of ensuring the vehicle's neutral steering. The study has revealed that in the case of an equipped vehicle it is necessary to reduce the tire pressure in the wheels on the equalizer trolley in correlation to the air pressure in the tires of the front wheels. The research results can be used both in operating the existing vehicles and for designing new ones