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This study focuses on changes in the friction characteristics of paved roads under various conditions from the viewpoint of traffic safety. In general, the braking characteristics of road vehicles are examined using the μ–s characteristics of the tires. Therefore, in our research, we used three types of limited datasets and identified them using the Magic Formula proposed by Prof. Pacejka. Based on various experiments, it was shown that changes in the road surface environment, such as dry and wet conditions, significantly affect the μ–s characteristics, and this influence varies significantly depending on the pavement conditions. In this study, as the first stage of the analysis of these influences, it was clarified that the difference in the friction characteristics of wet and dry road surfaces varies significantly depending on the pavement surface, which is based on experimental results obtained using actual roads. As this variation is closely related to the safety of actual road traffic, we used a brush model, which is a dynamic model of the road surface and tires, to clarify the differences in this characteristic.

Studying the relationship between the suspension geometry and the pitching posture during turning in a personal mobility vehicle with two front wheels and one rear wheel that tilts inward when turning, it is shown that the combination of front telescopic type suspension and rear swing arm type suspension is appropriate to simultaneously avoid pitching of the vehicle body during turning and disturbance from the road surface due to the tread change on wheel stroke.

This study deals with the possibility of construction of a 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. At these levels of automated driving, the controller needs to control the vehicle. However, the road surface condition, especially the road friction coefficient on wet roads and 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 continuous measurement of the road friction characteristics, such as the μ-s characteristics. It is shown that the μ-s characteristics are continuously measured using the MF generally used in tire engineering, and the friction characteristics identified from the results are sufficiently satisfactory.

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.

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.

This paper is part of the Proceedings of the 2019 Bicycle and Motorcycle Dynamics Conference: A Symposium on the Dynamics and Control of Single Track Vehicles held in Padova, Italy September 9th through 11th in the year 2019.Artifact ID: 25

This abstract is part of the Proceedings of the 2019 Bicycle and Motorcycle Dynamics Conference: A Symposium on the Dynamics and Control of Single Track Vehicles held in Padova, Italy September 9th through 11th in the year 2019.Artifact ID: 15Note that this abstract is the first page of the submitted full paper. The authors declined to release the full paper in the proceedings collection. Requests for the full paper should be made to the corresponding author.

Traffic congestion and lack of parking spaces in urban areas etc. may lessen the original benefits of cars, and now new ultra-small mobility concepts called personal mobility vehicles (PMVs) are receiving attention. Among them, PMVs with an inward tilting mechanism in order to avoid overturning on turning, as in motorcycles, look realistic in new, innovative traffic systems. In this study, PMVs with an active inward tilting mechanism with three wheels, double front wheels and single rear wheel, were studied regarding front inner wheel lifting phenomena, capability of obstacle avoidance and energy balance of active tilting mechanism. Based on a comprehensive study of inner wheel lifting and obstacle avoidance, PMVs with a front wheel steering system as the most realistic specification were compared on capability of obstacle avoidance with passenger cars and motorcycles with those that have current market experience, and showed better capability. Although the energy consumption of an active inward tilting mechanism might be in conflict with the energy efficiency of small PMV concepts, the energy needed to tilt PMVs was very little compared with the general energy consumption of driving. It was clarified that the new PMV concepts with inward tilting mechanism have sufficient social acceptability from both mandatory points of safety and efficiency.

Die Reduzierung der CO2-Emissionen erfordert derzeit die groesste Aufmerksamkeit in der Fahrzeugentwicklung. Im Beitrag werden hierzu die Potenziale einer Verbrauchsreduzierung durch verbesserte Effizienz im Gesamtfahrzeug diskutiert. Die vorgestellten Massnahmen umfassen die Verbesserung des Wirkungsgrades des Gesamtantriebs, die Reduzierung der Fahrzeugmasse und des Reifenrollwiderstandes. Um das Potenzial dieser Massnahmen zu bewerten wurden verschiedene Fahrzeugvarianten in ihrem jeweiligen Verbrauchsverhalten mittels Computersimulation untersucht. Als Basisfall ist hierbei ein gaengiger serienmaessiger Kompaktwagen zugrunde gelegt, der ein hypothetisches Hybridantriebssystem enthaelt. Die Ergebnisse der Simulationsstudien des untersuchten Falls werden am Beispiel des Neuen Europaeischen Fahrzyklus (NEFZ) vorgestellt; es wird festgehalten, dass die Massnahmen den Kraftstoffverbrauch nahezu um die Haelfte reduzieren koennen und dies auch bei einem Kompaktwagen, der bereits mit Hybridtechnik ausgeruestet ist. Die Ergebnisse bestaetigen demnach die hohe Bedeutung von Technologien zur Reduzierung der Fahrzeugmasse und des Reifenrollwiderstandes.

“Rubber” is an indispensable material as an element for automobile, because of its original characteristics such as big transformation and restoration, which other materials do not have. There are no doubts that the technologies utilized in components such as tires, bushes, insulators and seals have supported the history of automotive evolution for more than 100 years. Due to the flexible property of “Rubber”, automobiles have gained practicable durability and reliability in components such as bodies, power trains and axles etc. At the same time, automobiles have gained good comfort for passengers. It is also well known that automobiles have highly increased in their vehicle dynamics level, such as driving, handling and braking, by the ever improving road contact ability of the pneumatic tires. Now days, the current issues in automobile development are focused around minimizing the negative aspects such as environmental impact, traffic congestion and traffic accidents and maximizing the positive aspects such as fun, delight, excitement and comfort. “Rubber” must play more important part in such efforts. Expectations for the “Rubber” are discussed from an automotive standpoint, including author's personal ideas.