Çok akstan yönlendirilen araçların dinamik modellenmesi ve analizi.


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Makina Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2006

Tezin Dili: İngilizce

Öğrenci: Kerim Bayar

Danışman: YAVUZ SAMİM ÜNLÜSOY

Özet:

Four wheel steering (4WS) is a concept proven to be beneficial in low speed applications requiring large steering angles, which is the case in city traffic or parking. By steering the rear wheels in the opposite direction to the front ones, maneuverability can be improved. However, a conflict is encountered at high speeds for all the steering strategies developed. If sharper response is achieved, this is at the expense of undesirably large vehicle sideslip angles. On the other hand, small vehicle sideslip angles are associated with heavy understeering behavior. It is not possible to improve both simultaneously in case of two-axle 4WS vehicles. The object of this study is the simulation of various steering configurations for multi-axle vehicles in an attempt to find a means of solving the problem of 4WS and to determine the best steering strategy. In addition to two-axle vehicles which have been extensively studied in literature, three- and four-axle vehicles are taken into consideration. By extending the strategies used for 4WS two-axle vehicles, new strategies are established for three and four-axle vehicles. An integrated non-linear ride and handling model in Matlab & Simulink environment considering sprung and unsprung mass motions, wheel and tire dynamics, is used for simulations. It is shown by case studies that, with the application of the derived strategies for three and fouraxle vehicles, lateral acceleration and yaw velocity responses can be improved without degrading vehicle sideslip angle.