scholarly journals An example of a power-off maneuver of a vehicle without a straight line motion control

2021 ◽  
Vol 58 (2) ◽  
pp. 63-80
Author(s):  
Jerzy Kisilowski ◽  
Jarosław Zalewski

In this paper some selected results related to motor vehicle dynamics have been presented basing on the computer simulations of a sports two-seater performing a power-off straight line maneuver with different road conditions and the lack of a straight-line motion control having been included. All simulations have been performed in the MSC Ad-ams/Car environment and the adopted maneuver was performed at the instant speed of 100km∙h-1. The selected phe-nomena have therefore been observed along the road long enough to relate them to different aspects of vehicle dynam-ics and the road traffic safety research. The adopted vehicle’s model moved along the flat and the randomly uneven road with the almost similar and the almost different profiles for the left and the right wheels. Additionally, two values of the coefficient determining the maximum amplitude of road irregularities have been selected, i.e., 0.3 for the lower and 0.9 for the higher irregularities. This meant that the road conditions have been considered as one of the main factors possibly affecting disturbances of the motor vehicle’s motion. Such research seems valuable from the point of view of the road safety and the vehicles’ maintenance. A power-off straight maneuver is not very often performed during the normal road traffic and might seem useless. However, in this case it seemed essential to test the response of a vehicle’s model to such factors as, e.g., the uneven loading, suspension characteristics, etc. This in turn might prove valuable when considering, e.g., the additional con-centration of a driver to overcome the external disturbances acting on a moving vehicle. The presented research is the second part of the paper (Kisilowski, 2019) where the power-off maneuver was considered but with the straightforward motion control. Here, the straight-line control has been switched off to examine an untypical situation where, for example a driver loses consciousness, and the vehicle moves freely along the road.

2019 ◽  
Vol 50 (2) ◽  
pp. 57-76 ◽  
Author(s):  
Jerzy Kisilowski ◽  
Jarosław Zalewski

In this paper the selected phenomena related to motor vehicle’s motion have been considered basing on a computer simulation. The vehicle performed a power-off straight line maneuver with different road conditions being included. All simulations have been performed in the MSC Adams/Car environment based on the available sports two-seater vehicle model, realizing the adopted maneuver at the instant speed of 100km/h. This enabled observation of the selected phenomena along the road long enough to relate them to different aspects of vehicle dynamics research. As for the randomly uneven road, almost similar and almost different profiles have been assumed for the left and right wheels of the vehicle. Additionally, two values of the coefficient determining the maximum amplitude of road irregularities have been selected: 0.3 for lower and 0.9 for higher irregularities, so the road surface conditions along with the flat road have been considered as one of the factors causing disturbances of the motor vehicle motion. Such research seems valuable from the point of view of road traffic safety and vehicle maintenance. This specific example is a presentation of the possible research on vehicle dynamics as well as a potential background for further considerations including different types of vehicles along with almost different road profiles for the left and right wheels of the given vehicle model. A power-off straight maneuver is not performed very often in normal road traffic. However, such test could be valuable when analyzing influence of the selected motor vehicle parameters, such as uneven loading, suspension characteristics, etc. on such maintenance features as stability, steerability and the influence of external disturbances acting on the moving vehicle. Further research provides different maneuvers and different simulation conditions.


2018 ◽  
Vol 121 ◽  
pp. 285-293
Author(s):  
Mirosław Nader ◽  
Krzysztof Kielczyk

Stable and slidable roofs of the semitrailers are usually characterized by low weight and easy handling, which equals directly into comfort of use, longevity of the system and the time needed to open or close. However, not always an operational advantages of roofs go hand in hand with their durability, especially in the snowfall situation or sudden changes of the road lane by a set of vehicles: a truck tractor – a semitrailer. The analysis of homologation regulations shows that today there are no precise requirements and physical testing / strength methods for assembled roofs of the semitrailers as components. The test methods for complete vehicle bodies (including the roof), which have destructive nature, are described in European standards, e.g. EN 12642:2017 "Securing of cargo on road vehicles – Body structure of commercial vehicles – Minimum requirements" [6], internal German regulations, e.g. VDI 2700:2004 "Securing of loads on road vehicles" [8] or Directive DCE 9.5:2008 ”Load security for transportation of load containers on utility vehicles in road traffic” [7]. A non-destructive, possible to perform, testing method for the roof as a component - is calculation method. The results of the performed tests allow to conduct development works over improving the vehicle’s system security (including the introduction of new semitrailers roofs design solutions and verification of existing ones). The carried out strength tests give possibilities to optimize and adapt the roofs to the transported loads, e.g. stable lifting roofs used in transport of divisible loads, or sliding roofs used in the transport of non-separate loads. The strength testing of the semitrailer’s roofs is highly justified from the point of view of securing the load and safety of passengers, drivers and other road users primarily. The requirements and limitations of the mentioned testing methods are not - in the authors opinion - 100% of realistic and possible deformation during the real vehicle’s road traffic. On the other hand, the cited documents exists as recognized regulators in the international arena of the road traffic legislation. The work’s aim is demonstrating the benefits of using reinforced roofs in all types of the semitrailer’s bodyworks.


2017 ◽  
Vol 24 (s1) ◽  
pp. 16-24 ◽  
Author(s):  
Marcin Budzyński ◽  
Dawid Ryś ◽  
Wojciech Kustra

Abstract Port towns are strategic places from the point of view of transport systems. They form integration junctions for various transport branches , apart from the traditional - road and railway ones , also for water( sea) transport which is active there. Moreover, air transport comes also into consideration , whose efficient functioning must be connected with good accessibility, that concerns sea transport as well. Efficient and safe servicing the ports is crucial for their functioning. Problems associated with the overloading of lorries, which leads to degradation of road surface structure , observed in Gdynia, are discussed as an example in this paper. Problems of road traffic safety (RTS) are presented in this paper on the example of Gdańsk. The two issues: the road traffic safety and road surface degradation constitute only some transport problems of port towns , but they are very important, from the point of view of their specificity, for integration junctions of all the transport branches for people and goods. However, in discussing selected aspects of transport in port towns it is necessary to refer to the managing of integrated transport system with taking into account its traffic safety aspects.


2011 ◽  
Vol 97-98 ◽  
pp. 449-452
Author(s):  
Li Wei Hu ◽  
Yu Long Pei ◽  
Mei Ru Chen

This paper analyses the source and development of fault tolerance theory, and discusses the working process of fault tolerance, and illustrates the workflow and dependability of fault tolerance. So there is a widespread belief that this is feasible that fault tolerance theory is used in the traffic safety study. Base on summarizing fault tolerance factors, the paper gives fault tolerance conceptual model primarily which could be used in the road traffic safety research. Above all, the paper presents a new idea which study traffic safety issues from the perspective of fault-tolerant , and this is important core content of the paper, and is the purpose of writing this article too.


2011 ◽  
Vol 219-220 ◽  
pp. 945-948
Author(s):  
Li Wei Hu ◽  
Yu Long Pei ◽  
Xue Li

Base on researching the source and development of fault tolerance theory, this paper discusses the working mechanism of fault tolerance, and illustrates the workflow and dependability of fault tolerance. So there is a widespread belief that this is feasible that fault tolerance theory is used in the traffic safety study. Through summarizing the progress of the fault-tolerant study in road traffic field at home and abroad, the paper gets some enlightenment from these literatures, finally gives the prospect of fault-tolerant theory which is used in the road traffic safety research.


2016 ◽  
Vol 11 (4) ◽  
pp. 251-258 ◽  
Author(s):  
Emilia Kuliczkowska

In this paper, road pavement collapses resulting from sewer leakage are divided into six categories: negligible, marginal, considerable, serious, very serious and catastrophic, with the categorization being based on two criteria, both related to traffic safety, i.e., the number of fatalities caused by sinkholes, and the extent of the road pavement damage. The causes of road pavement collapses are also discussed. The study involved analyzing the deterioration of sewer pipes with long service lives, focusing on the most common materials, i.e., concrete and vitrified clay. The results of the sewer inspections performed by the Kielce University of Technology suggest that the spot and linear defects detected in sewers of this type can be divided into three groups. The findings were used to formulate some recommendations on how to improve road traffic safety by preventing road pavement collapses.


2012 ◽  
Vol 22 (1) ◽  
pp. 75-81
Author(s):  
Marijan Rajsman ◽  
Georg-Davor Lisicin

The objective of this paper is to analyse road traffic safety in the Republic of Croatia based on the selected indicators which were used by the legislator in bringing the Law on Road Traffic Safety which has been in force since 28 July 2004, and the achieved effects in reaching the desired safety level in the three-year period from 2005 to 2007. The aim of the research is to establish a prognostic trend of the values of the studied indicators in the time period following the enforcement of new legal regulations. Adequate safety indicator values for the respective period were analyzed using the methods of analysis and synthesis, mathematical statistics as well as trend assessment based on the found mathematical prognostic models. Based on the results of this research it was found that the basic hypothesis according to which the implementation of new legal guidelines had to result in positive change in the condition of road traffic safety, failed to be confirmed. A change in the road traffic safety improvement strategy has been proposed as well as a more significant participation and recognition of the profession and science in this field which is of great significance for the society. KEY WORDS: influence of legal regulations, road traffic safety, effects and tendencies


2012 ◽  
Vol 21 (2) ◽  
pp. 129-140
Author(s):  
Vinko Višnjić ◽  
Marko Pušić

The safety of road traffic in small towns in the Republic of Croatia is not at a satisfactory level. As proof, the safety of road traffic participants in the area of the town of Nova Gradiška and its wider environment has been studied and analyzed. The paper includes the available data in the period from 2000 to 2007. The analysis and the assessment of road traffic safety can be applied also to other towns and counties of the Republic of Croatia. Having in mind that there are 531 settlements in the Republic of Croatia (119 towns and 412 districts), out of which only 78 are larger than 10,000 inhabitants or 14.69% of the total number, which means that the analysis could be made for any settlement in the Republic of Croatia. The road traffic safety assessment was conceived according to the modified Smeed model which may be applied for any settlement or town. The road traffic safety analysis has led to the conclusion that safety of all the traffic participants is endangered. This paper provides solutions about what has to be done in order to reduce the danger to all the road traffic factors. KEY WORDS: drivers, traffic, traffic accidents, safety and small towns


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