ARTICLE | doi:10.20944/preprints202212.0034.v1
Subject: Engineering, Automotive Engineering Keywords: personal mobility vehicle; active tilting; steering axis; steering disturbance; load reaction force; slanted road; rutted road
Online: 2 December 2022 (02:24:36 CET)
Personal Mobility Vehicle (PMV) which has an inward tilting angle turns with the lateral force due to large camber angle, so it is necessary to consider the lateral movement of the tire vertical load axis during turning. Although the steering torque mechanism are very different from those of automobiles, there are not many examples which studied the steering torque mechanism of PMV. In this paper, based on the effects of six components force acting on the tires, a method for setting the steering axis specifications is derived, including the geometrical minimization of steering moment disturbance due to the vertical load reaction force during turning. Although, automobile tires have a significant ground camber angle when traveling on rutted roads, they do not have it on slant roads because the vehicle body tilts along the road surface. On the other hand, in PMV, the vehicle body always keeps upright when traveling both on slanted roads and on rutted roads. Therefore, the tires have ground camber angles on both types of road surface. We study the straight running ability under such road surface disturbances based on the geometrical minimization of steering moment disturbance due to the vertical load reaction force during turning. This straight running ability can be a remarkable strong point of PMV with an inward tilt mechanism.
ARTICLE | doi:10.20944/preprints202208.0033.v1
Subject: Engineering, Automotive Engineering Keywords: road friction; environmental information; measurement; friction estimation
Online: 2 August 2022 (04:18:45 CEST)
This paper deals with the possibility for construction of the database on friction coefficient on the actual roads from the viewpoint of traffic safety. A measurement algorithm is determined in order to construct road friction measuring device. Next, the tires used for measurement are selected and the characteristics are measured using bench tire characteristic tester, and the measuring device is designed and constructed based on the characteristics. Finally, using this device, the measurement results of the road friction characteristics for two types of road surfaces are shown.
ARTICLE | doi:10.20944/preprints202111.0268.v1
Subject: Engineering, Automotive Engineering Keywords: Road Friction; Environmental Information; Measurement; Friction Estimation
Online: 15 November 2021 (14:35:48 CET)
This research deals with the possibility for construction of the database on the braking friction coefficient for actual roads from the viewpoint of traffic safety especially for automated driving such as level 4 or higher. In an automated driving such levels, the controller needs to control the vehicle, but the road surface condition, especially the road friction coefficient on wet roads, snowy or icy roads, changes greatly, and in some cases, changes by almost one order. Therefore, it is necessary for the controller to constantly collect environment information such as the road friction coefficients and prepare for emergencies such as obstacle avoidance. However, at present, the measurement of the road friction coefficients is not systemically performed, and a method for accurately measuring has not been established. In order to improve this situation, this study examines a method for continuously measurement for the road friction characteristics such as μ-s characteristics.