https://repository.up.ac.za/bitstream/handle/2263/3060/Uys_Suspension(2007).pdf

Suspension settings for optimal ride comfort of off-road vehicles travelling on roads with different roughness and speeds

Roll dynamics in heavy freight vehicles is characterized in driving conditions by the lateral load transfer coe A cient. The coe A cient tracking requires sophisticated measurement systems for assessing the wheels' normal loading. In this paper a new recursive non-linear lateral load transfer estimator employing sensors that are already used on a vehicle in combination with additional units that are not sophisticated for the implementation is described. The proposed algorithm integrates two subsystems— separate estimators for the tractor and the trailer. The e rst estimator is based on slip information of the driving wheels, while the second estimator fuses the tractor estimation and the modelled trailer dynamics by the extended Kalman e lter. The novel approach was evaluated on a sophisticated computer simulator of the Freightliner Century Class tractor semitrailer. The simu- lation analysis shows that the proposed algorithm provides robust operation and good tracking performance. This approach enables a practical realization of a low-cost solution for the rollover prevention in real heavy freight vehicles.

/pdf/roll-dynamics-and-lateral-load-transfer-estimation-in-ccsftxhlzd.pdf

Roll dynamics and lateral load transfer estimation in articulated heavy freight vehicles

The goal of the study was assessment of the hour-long training involving handling virtual environment (sVR) and watching a stereoscopic 3D movie on the mechanisms of autonomic heart rate (HR) regulation among the subjects who were not predisposed to motion sickness. In order to exclude predispositions to motion sickness, all the participants (n=19) underwent a Coriolis test. During an exposure to 3D and sVR the ECG signal was continuously recorded using the Holter method. For the twelve consecutive 5-min epochs of ECG signal, the analysis of heart rate variability (HRV) in time and frequency domains was conducted. After 30 min from the beginning of the training in handling the virtual workstation a significant increase in LF spectral power was noted. The values of the sympathovagal LF/HF index while sVR indicated a significant increase in sympathetic predominance in four time intervals, namely between the 5th and the 10th minute, between the 15th and the 20th minute, between the 35th and 40th minute and between the 55th and the 60th minute of exposure.

Heart rate variability (HRV) during virtual reality immersion.

Effects of wind barrier on a vehicle passing in the wake of a bridge tower in cross wind and its response

Abstract The article presents the results of research on the total reaction time of drivers in real traffic conditions. The tested driver had to react to a complex signal by performing a braking manoeuvre. The measurements were based on the author’s method combining the measurements of reaction time during the actual driving with their computer analysis. The research group consisted of 15 drivers with different seniority of driving licences. The study measured the time of perception and the time of leg transfer from the accelerator pedal to the brake pedal. The results were subjected to analysis and on its basis conclusions were formulated.

/pdf/drivers-reaction-time-research-in-the-conditions-in-the-real-1ro31d1hgi.pdf

Drivers ’reaction time research in the conditions in the real traffic

Analiza ruchu samochodu dwuosiowego na tle modelowania jego dynamiki

Symulatory jazdy samochodem

Extract. The paper presents results of research on the reaction time of drivers of motor vehicles in case of accident risk. These studies have been conducted in an autoPW driving simulator research project N509 016 31/1251. During a simulated pre-accident situation, a test driver, as he was trying to avoid a collision with an obstacle, has been forced to perform a braking manoeuvre. 107 people of different age and driving experience have been studied. Various scenarios describing risk situations (the speed of a car driven by a tested driver, the distance between the vehicles at the initial moment) have been considered.Reaction times were determined at the controls of the vehicle and they have been presented in a time to collision function. The presented results provide important information on the analysed subject (for instance reaction time dependence on risk time). They have also confirmed the usefulness of this type of simulation studies in connection with the possibility of fairly accurate reproduction of the environment appearance and an event scenario in relation to possible real situations.

http://yadda.icm.edu.pl/yadda/element/bwmeta1.element.baztech-article-BAT2-0004-0021/c/httpwww_ein_org_plsitesdefaultfiles2012-04-05.pdf

Driver's reaction time under emergency braking a car - research in a driving simulator

One purpose of accident reconstruction is to define the motion parameters of the participants before the accident. This paper examines some issues related to the assessment of computational accuracy concerning reconstruction of a vehicle's motion from the threat occurrence until the accident or accident avoidance. The basic method of computation credibility assessment is experimental verification of models. In the case of errors resulting from inaccuracies of value assessments for parameters, there are several methods that allow for assessing an error in analysis. These methods include determined methods (e.g., total differential method and extreme values method) and probabilistic methods (e.g., Gauss method, methods with the use of stochastic processes, Monte Carlo method). These methods were compared on the basis of their application in the case of a braking process study of a vehicle in rectilinear motion. Also for the aforementioned case, the results obtained by means of various computational methods of vehicle motion (analytical and simulation models) were compared with the outcome of the experimental study. Findings indicate the failure to consider inaccuracies in data assessment may lead to a false hypothesis of the course for a given accident situation. However, the selection of the best method depends on the adopted model of the analyzed phenomenon and the possibility to define data. Limitations of each method should be considered when choosing a method.

Zbigniew Lozia

Papers

Analiza ruchu samochodu dwuosiowego na tle modelowania jego dynamiki

Symulatory jazdy samochodem

Driver's reaction time under emergency braking a car - research in a driving simulator

Uncertainty Study of Road Accident Reconstruction - Computational Methods

Possible Errors Occurring During Accident Reconstruction Based on Car “Black Box” Records