The importance of yaw motion feedback in driving simulators

Abstract

Currently the development and evaluation of winter vehicle handling characteristics are almost solely based on subjective assessments (SA) done by expert drivers. This is both expensive and time consuming, and therefore in conflict with the general goal of shortening project development and testing time meanwhile fulfilling more restrictive and demanding specifications.A more effective vehicle dynamics evaluation would be to use Computer Aided Engineering (CAE) for objective testing. Although objective evaluations are well defined for high friction conditions, or summer testing, the correlations between objective metrics (OM) and SA are still under development (Chen & Crolla 1998, Harrer et al. 2006, King et al. 2002, Nybacka et al. 2014a. Furthermore, these objective methods are not directly applicable for low friction testing, or winter testing, because the added challenge of constantly changing surface conditions. This causes both low signal-to-noise ratio measurements and low robustness, or repeatability, of the results. This difficult situation is increased by the fact that there is only one short winter test season per year and hemisphere, which limits the possibilities to shorten project times, as several winter test periods are normally required. All the above are motivations to understand: − How expert drivers perform their winter SA. − How objective tests, measurements and OM shall be defined for winter tests. − How OM and SA correlate in winter conditions and compares with summer conditions. During this research, a winter test expedition was performed in order to develop the methods to evaluate vehicle dynamics handling on winter conditions, see Figure 1. The goals of the performed tests were to study how winter objective testing should be performed when using steering robots. By identifying the suitability of different objective test manoeuvres, methods and/or procedures; the effects that the surface conditions have on the results and their repeatability, and if key OM are robust enough to describe the vehicle performance during changing surface ABSTRACT: This paper presents a test procedure developed to gather good quality data from objective and subjective testing on winter conditions. As the final goal of this test is to analyse the correlation between objective metrics and subjective assessments on winter for steering and handling, this procedure has to ensure a minimum change of the surface properties, which has a major influence on vehicle performance, during the whole test campaign. Therefore, the method presented keeps the total test time very low and allows similar vehicle configurations to be tested, objectively and subjectively, very close in time. Moreover, continuous maintenance work on the ice is performed. Reference vehicles are also used to monitor the changes on vehicle performance caused by weather conditions, which are inevitable. The method showed to be very effective. Initial results on objective metrics and subjective assessments are also presented.