Wyniki wyszukiwania - BazTech

1

Wyznaczenie dopuszczalnej prędkości pojazdu samochodowego w czasie przejazdu po mobilnej platformie pomiarowej

Jagiełowicz-Ryznar C.

Logistyka

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2014

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nr 6

14237--14245, CD 6

PL

W pracy przedstawiono wyniki obliczeń numerycznych obciążenia dynamicznego osi pojazdu samochodowego (PS) w czasie przejazdu po mobilnej platformie pomiarowej (MMP). Przyjęto wymuszenie kinematyczne pochodzące od MMP, po której porusza się PS ze stałą prędkością. Do analizy przyjęto model dynamiczny zawieszenia o 2 stopniach swobody. Zbadano wpływ prędkości pojazdu i współczynnika tłumienia w amortyzatorze(w czasie ruchu opadania) na maksymalną dynamiczną siłę nacisku. Określono na tej podstawie współczynnik dynamiczny obciążenia osi. Jest to istotne ze względu na bezpieczeństwo jazdy (pomiaru) po MMP.

EN

The numerical calculations results of dynamic axle load of automotive vehicle (PS) during the ride on the mobile measurement platform (MMP) were presented in this paper. The kinematic force coming from MMP, which the PS moves on at the constant velocity, was taken. The suspension dynamic model with two degrees of freedom was taken to the analysis. Impact of the vehicle velocity, the platform height, damping coefficient in the shock absorber (during the compression movement), and the rigidity of tires, on the maximum dynamic force was studied. According to this study, the maximum dynamic axles load coefficient, when it is driven on the MMP, was determined. It is essential for the safety during the movement on the MMP.

2

Influence of Pressure and Load on Radial Deformation of the Tyre

Olszewski Z., Waluś K. J.

Machine Dynamics Research

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2012

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Vol. 36, No. 3

65-71

EN

Adhesive tire-road interaction significantly depends on the tyre operational parameters and directly affects safety of the vehicle. Phenomena occurring in the area of contact between the ground and tyre are crucial to maintain directional stability and the ability to transfer driving forces. Changes in pressure and tire load affects the geometry of the contact area and lead to changes in the coefficient of adhesion. This paper presents results of research and discusses effect of pressure and vehicle axle radial load on the geometric features of the contact zone.

3

Test VDA ISO TR3888 on the testing bench for steer by wire system

Voženilek R., Brabec P., Maly M.

Journal of KONES

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2010

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Vol. 17, No. 4

561-565

EN

The Technical University of Liberec, Department of Vehicles and Engines, has developed a design of a testing bench which would enable the testing of directional control systems. The objective of the newly designed equipment is to incorporate a real tyre as well as aflexible mounting of the axle components into the tested system. Future of car s will be connected with systems of type steer by wire. This system need to be testing on the testing bench before real test in the car. One method for assessing can be investigation control deviation during test VDA ISO TR3888. The paper will describe measurement of the real car with conventional directional control during test VDA ISO TR3888 and simulation of the system steer by wire on the testing bench. The experimental steer by wire system forms hydraulic circuit with two double-acting hydraulic cylinders with a unilateral piston rod and two proportional valves Parker D1FP. Every wheel front of axle is control alone. The PID regulators were usedfor control of the positioning action. In particular, the testing bench for the testing of steering at zero angular speed of wheels, VDA ISO TR 3888 tests on the testing bench are presented in the paper.

4

Action of force in steering mechanisms of vehicles in an experimental laboratory establishment

Brabec P., Maly M., Voženilek R.

Journal of KONES

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2009

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Vol. 16, No. 3

55-62

EN

The safe and stable control ofa vehicle undoubtedly belongs to one of the most important requirements that relate to the vehicle 's design and operation. Consequently, in the near future, so called steer-by-wire systems could become the next stage in the control system development. A number of new, modern vehicles presented by car makers at important car shows definitely show how topical the issue is. If we want to create a design for this steering system, we have to know the action offorce very well. An experimental laboratory establishment for measuring and optimizing the steering system of vehicles was developed in our centre. The testing equipment is made of aluminium sections enabling the equipment to be quickly adapted to various vehicles ' axles and tyres. An exchangeable mat located under a tyre enables the system to create behaviour simulation for various surfaces with a different coefficient of adhesion. A sliding way assisted by a hydraulic jack under a tyre allows a change in axle load for example in accordance with the vehicle 's occupancy. A force sensor will be positioned between the jack and the mat to monitor the load adjustment. The testing stand design enables us to determine responses and behaviour of the system including tyres.The safe and stable control ofa vehicle undoubtedly belongs to one of the most important requirements that relate to the vehicle 's design and operation. Consequently, in the near future, so called steer-by-wire systems could become the next stage in the control system development. A number of new, modern vehicles presented by car makers at important car shows definitely show how topical the issue is. If we want to create a design for this steering system, we have to know the action offorce very well. An experimental laboratory establishment for measuring and optimizing the steering system of vehicles was developed in our centre. The testing equipment is made of aluminium sections enabling the equipment to be quickly adapted to various vehicles ' axles and tyres. An exchangeable mat located under a tyre enables the system to create behaviour simulation for various surfaces with a different coefficient of adhesion. A sliding way assisted by a hydraulic jack under a tyre allows a change in axle load for example in accordance with the vehicle 's occupancy. A force sensor will be positioned between the jack and the mat to monitor the load adjustment. The testing stand design enables us to determine responses and behaviour of the system including tyres.

5

Application of dynamic slip characteristics in simulation of vehicle motion

Reński A., Sar H.

Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska

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2008

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z. 5/72

83--94

EN

The paper presents the application of tyres dynamic characteristics describing vehicle non-steady-state axle side slip. The influence of side slip dynamics was included in characteristics described additionally as a function of slip angle derivative about time. The results of vehicle motion computer simulation in this article are presented as time plots of vehicle yaw velocity, COG lateral velocity and axles side slip angle. Especially in case of yaw velocity and rear axle side slip angle it can be seen that application of axle non-linear dynamic side slip characteristics make it possible to better reproduce the real motion of a vehicle, in comparison to linear characteristics obtained for steady-state (quasi-static) motion conditions.

PL

W pracy przedstawiono zastosowanie dynamicznych charakterystyk opon opisujących nieustalone znoszenie boczne osi samochodu. Wpływ dynamiki zjawiska znoszenia został uwzględniony w charakterystykach sporządzonych również w funkcji pochodnej kąta znoszenia względem czasu. Wyniki symulacji komputerowej ruchu pojazdu w niniejszym artykule przedstawiono w postaci przebiegów czasowych prędkości kątowej względem osi z, prędkości poprzecznej środka masy oraz kątów bocznego znoszenia obu osi pojazdu. Rezultaty symulacji przeprowadzono dla różnych typów charakterystyk opon. Zwłaszcza z przebiegów prędkości kątowej względem osi z oraz kąta bocznego znoszenia osi tylnej wynika, że zastosowane w obliczeniach nieliniowe dynamiczne charakterystyki znoszenia osi pojazdu dają możliwość lepszego odwzorowania rzeczywistego ruchu pojazdu, niż liniowe charakterystyki otrzymane dla ustalonych warunków ruchu.