27 research outputs found
Application of the partial accelerations method to automobile handling evaluating
Запропонований метод дозволяє виконувати оцінювання керованості автомобілів з урахуванням або без урахування відведення, з різними типами привода й різних направляючих колесах за допомогою парціальних прискорень. Визначення бічних і дотичних реакцій на колесах автомобіля при повороті з урахуванням бічного відведення шин дозволяє більш точно оцінювати повороткість, стійкість і керованість автомобіля.Means of road transport plays an important role in the life of society. Efficiency of its operation determines the efficiency of the national economy as a whole. At steady driving on a straight or curved path with constant average linear or angular velocity and perturbation action it is necessary to influence the vehicle management controls in order to maintain a given course angle or constant radius turn. In this case, the ability of machines to respond adequately to the action (from handling) depends on its course and trajectory stability. Manageability is an important vehicle operational feature and it is closely related to road safety. On vehicle handling significantly affect lateral forces arising in contact of wheels with the road when turning. Vehicle turn can be carried out in three main ways – changing the angles between the longitudinal axis and steering wheels rotation plane of the machine due to their rotation, the change in position of one machine part on another (
articulated vehicles), as well as varying different sides wheels speed. The proposed method allows evaluating an automobile handling with or without accounting withdrawal, with various types of drive wheels and various steering wheels using partial acceleration. Determination of lateral and tangential reactions on automobile tire while turning in view tire slip allows more accurate evaluating of automobile maneuverability, stability and handling. Determination of vehicle total and partial angular accelerations during its driving into rotation with and without accounting withdrawal allows developing a vehicles handling improving algorithm with different tire types. Using of different ways in vehicle managing is complicating associated with machine design and control process by machine handling characteristics changing during applying the locking devices. The equations of front-wheel drive vehicles and all-wheel drive vehicles rotational motion when driving on curves without removal are the same. Appearance of
new ways to perform maneuvers such as turning movement with all the drive wheels (4WS), requires researching of movement trajectory, stability and handling of machines during specified maneuvering
СВІТОГЛЯДНІ АСПЕКТИ МІЖНАРОДНОЇ СПІВПРАЦІ ОСВІТНІХ ІНСТИТУЦІЙ УКРАЇНИ ТА ПОЛЬЩІ (World view aspects of international cooperation of the Ukrainian and Polish educational institutions)
Показано, що проблеми євроінтеграції “постсоціалістичних” країн зумовлені ігноруванням світоглядних
особливостей їхнього населення. Вказаний напрям наукового та прикладного вирішення цієї проблеми силами
науковців та викладачів вищої школи. Описана спільність цієї проблеми для Польщі та України і якісні переваги
кооперації
ВНЗ
цих
країн
у
цьому
напрямі (It is rotined that the problems of eurointegration of “postsocialisticheskikh” countries are conditioned ignoring of
world view features of their population. Direction of scientifi c and applied permission of this problem is indicated by
forces of scientists and teachers of higher school. Community of this problem for Poland and Ukraine and high-quality
advantage of co-operation is described INSTITUTE of higher of these countries
STABILITY OF WHEELED VEHICLES AS COMPLEX OPERATIONAL PROPERTIES
Different views on the definition of «stability of wheeled vehicles» are considered and the author’s own definition is offered. A version of the structure of stability properties as a complex op-erational property is offered
ЭКСПЕРТНАЯ ОЦЕНКА РАСПРЕДЕЛЕНИЯ РЕАКЦИЙ ДОРОГИ МЕЖДУ КОЛЕСАМИ АВТОМОБИЛЯ
The expert methodology for evaluating the road reaction distribution between vehicle wheels has been developed to determine the maximum values of speed, steering angle and the turning radius of the car on the condition of safe movement, as well as to determine the time of loss of its stability when entering and exiting the turn.Розроблено експертну методику оцінювання розподілу реакцій дороги між колесами автомобіля, яка дозволяє визначати максимальні значення швидкості, кута повороту керованих коліс і радіуса повороту автомобіля за умовою безпечного руху, а також момент часу втрати стійкості при вході та виході з повороту
Application of parallel observation method for automobile testing
Обґрунтовано доцільність використання методу паралельних спостережень з метою підвищення точності визначення параметрів автомобіля при випробуваннях. Показано практичну реалізацію методу паралельних спостережень на прикладі вимірювання сил опору руху автомобіля.The expediency of application the method of parallel observation with the aim of increasing the determination point of automobile parameters in testing is grounded. It is shown practical realization of parallel observation method for example of measuring resistance powers at automobile motion
Evaluation of Power Indicators of the Automobile Engine
A method for estimating the power characteristics of the car engine in various driving regimes is proposed. It is determined that the vol-ume of the free power (engine power reserve) allows the driver to implement the turning parameters and the time of its completion, which are set by the steering parameters, position and the speed of the steering wheels rotation. The engine power reserve is necessary to provide the required maneuverability indicators. The engine power during maneuvering is spent on overcoming the resistance to move-ment and on providing the impact controlled by the maneuver. The first component of the engine power can be called connected, and the second one can be called the free one or a controlled component. The received analytical expressions allow carrying out at the design stage a rational choice of capacity of the engine by the condition of maintenance of demanded properties of maneuverability. The developed method for constructing the refined acceleration characteristics of the engine makes it possible to determine the dynamic capabili-ties of the car, taking into account its design features and operating conditions
МОДЕЛЬ НЕЛІНІЙНОГО ВІДВЕДЕННЯ ЕЛАСТИЧНОГО КОЛЕСА АВТОМОБІЛЯ
A simple nonlinear model of the tire slip with known experimental dependences of the lateral force on the slip angle is offered.Запропоновано просту нелінійну модель відведення шини колеса автомобіля з використанням відомих експериментальних залежностей бічної сили від кута відведення
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