Wyniki wyszukiwania - BazTech

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Vehicle wheel positioning innovation on a machine for measuring the contact parameters between a tyre and the road

Jilek Petr

Archiwum Motoryzacji

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2023

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Vol. 100, nr 2

31--43

EN

This article deals with the development and proposal to increase the application of equipment for measuring the adhesion force between the road and the road vehicle. The device enabling the adhesion force measurement of a rotating vehicle wheel is called a dynamic adhesor. The actual position of the vehicle wheel relative to the road-simulating cylinder is, in the present embodiment of the dynamic adhesor, by means of a bolted clamping joint and stops. This embodiment has limiting applications. the test must be aborted, if the position of the vehicle wheel relative to the rotating cylinder changes. Therefore, the adhesor has been upgraded. The upgrade consists of adding a hydraulic control to allow repositioning of the vehicle wheel online without interrupting the experiment, from a workstation outside the rotating parts area. Input load values were determined from the adherent desired operating parameters and from the load simulation in the MSC Adams software. Hydraulic cylinders were designed in accordance with the results of the maximum operating loads and installation space. The current construction was adapted and supplemented with new parts for the use of these hydraulic cylinders. The article only deals with the area of new key elements. The equipment's use has been expanded by improving the dynamic adhesor, for example, with the possibility of simulating the vehicle wheel's driving behaviour when the vehicle is propped up, and in this way, the equipment can also be used for any required research in regard to noise emitted from the tyre's road contact. As a result of innovation, the use of the unique tyre-testing equipment has been expanded, increasing the safety and environmental friendliness of road vehicles.

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Modification of the adhesive force by changing the radial reaction on vehicle wheels

Jilek Petr, Krmela Jan, Berg Jan

Transport Problems

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2021

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T. 16, z. 1

179--186

EN

This article deals with the possibilities of adhesion force changes of a road vehicle. The authors present the possibilities of reducing the adhesion force of road vehicles and, at the same time, present their own system for changing the radial reaction of the vehicle wheels. This system removes the disadvantages of a commercially available SkidCar system. A representative road test is chosen in the article to determine the stability in a straight-line drive. Furthermore, the authors report the courses of characteristic parameters describing the behavior of a vehicle for driving a conventional car on a sliding surface and compared to the 50 % radial reaction of a vehicle driven with the SlideWheel on dry asphalt. It is clear from the measured runs that it is possible to change the adhesion force by changing the adhesion weight transmitted by the vehicle wheels. The use of the proposed SlideWheel system is possible for the purpose of verifying vehicle stability, while improving the driver's ability to operate the vehicle under reduced-adhesion conditions. The main goal of this paper is to design a system for reducing the adhesive force in an experimental car and perform experimental measurements.

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Change of driver’s response time depending on light source and brake light technology used

Jilek Petr, Vrabel Lubos

Zeszyty Naukowe. Transport / Politechnika Śląska

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2020

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z. 109

45--53

EN

This paper deals with finding out the influence of the type of light source of car brake lights on the reaction time of the driver of the preceding vehicle. The driver’s reaction time was measured in the form of pressing the brake pedal depending on the lighting of brake lights on the leading vehicle. The measurement evaluation consists of a comparison of the phase shift between the brake light signal of the first vehicle and the brake light signal of the second vehicle. The experimental measurement was performed for five people using the classic light bulb, afterwards, an LED light source for the brake lights of the first vehicle. The records confirmed that the driver’s reaction time depends on many factors, with the source and intensity of the brake lights also playing an important role. Further, it affects the reaction time and the activity or inactivity of the rear sidelights. The reaction time of the driver of the preceding vehicle was extended with their activation.