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A Proposal of Wheel/Rail Contact Model for Friction Control
Kosuke Matsumoto,Yoshihiro Suda,Hisanao Komine,Takuji Nakai,Masao Tomeoka,Kunihito Shimizu,Masuhisa Tanimoto,Yasushi Kishimoto,Takashi Fujii 대한기계학회 2005 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.19 No.1S
Controlling the friction between wheel and rail is direct and very effective measures to Improve the curving performances of railway trucks, because the curving performances depend much on friction characteristics Authors have proposed a method, "fllction control", which utilizes friction modifier (KELTRACKTM HPF) with onboard spraying system With the method, not only friction coefficient, but also fuction characteristics can be controlled as expected In this study, MBD simulation is very valuable tool to foresee the effect of the contiol In advance of experiment With real car And the creep characteristics of wheel/rail contact With the friction modifier takes very Important role In the simulation In this paper, authors propose a theoretical model of wheel/rat I contact condition considering the creep characteristics of friction modifier, Which is derived the application of principle tribological theories<br/>
Chihiro Nakagawa,Yoshihiro Suda,Kimihiko Nakano,Shoichiro Takehara 대한기계학회 2009 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.23 No.4
Recently, the personal mobility vehicle (PMV), a vehicle suitable for personal use, has been developed. It moves at low speed and is sufficiently small that it can be ridden in pedestrian space. This vehicle is expected to be a new method of transportation that is practical and environmentally friendly. As one form of PMV, the authors propose a twowheel vehicle with two modes: a two-wheel steering and two-wheel driving bicycle mode and a parallel two-wheel mode. This vehicle has four electric motors, two for driving and two for steering, and one generator connected to the pedals. In the bicycle mode, the rider rotates the pedals to generate electric power, and the motors in the wheels produce torque using the generated energy. The front and rear wheels are steered by the electric motor according to the angle of the handle. Therefore, this bicycle is controlled by a steer-by-wire and a drive-by-wire system. In the parallel two-wheel mode, the vehicle is stabilized according to the theory of the inverted pendulum. In this paper, we focus on the bicycle mode and analyze its stability. Stabilizing the bicycle is not easy since the proposed vehicle has tires with small diameters and the traveling speed is assumed to be low. It is known that the stability of bicycles is tuned by adjusting the bicycle parameters and changing the rear steer angle. However, since we aim to use the vehicle in a narrow walking space at low speed, such conventional methods are not always suitable. The authors propose the stabilization of the bicycle using driving forces and design a controller using linear-quadratic control theory. The results of the numerical simulations show the proposed method is effective in stabilizing the bicycle.
Application of Driving Simulator to Dilemma Zone Experiments
Toshihiko Oda,Yoshihiro Suda,Shinji Tanaka,Daisuke Yamaguchi 한국자동차공학회 2008 한국자동차공학회 Symposium Vol.2008 No.9
At the onset of the yellow interval, a driver approaching a signalized intersection has to decide to either stop if he has enough distance or proceed to cross the stop line. A dilemma zone refers to a highly hazardous situation where an abrupt braking may cause a rear-end collision if a driver stops and an angle collision may occur if he crosses the intersection. To prevent drivers from being caught in the dilemma zone, a traffic signal control method called Dilemma-Free was introduced. In this method, there is an important issue about the model of driver/vehicle behaviors involving the reaction time of a driver to take braking actions and the deceleration rate of a vehicle. This paper describes a study of stopping behavior of drivers in the dilemma zones. With the use of a Driving Simulator, experiments were conducted to extract driver model parameters under dilemma zone situations. Results show that the reaction time depends heavily on various details of traffic situations. It is confirmed that the driver’s decision in a dilemma zone is influenced by the vehicle’s distance to the stop line, the approach speed and the indication of pedestrian signal.
Hiroyuki Sugiyama,Kohei Araki,Yoshihiro Suda 대한기계학회 2009 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.23 No.4
An on-line and off-line hybrid contact algorithm for modeling wheel/rail contact problems is developed based on the elastic contact formulation. In the hybrid algorithm developed in this investigation, the off-line tabular search is used for predicting the location of tread contact points, while the on-line iterative search is used for predicting flange contact points. By so doing, a computationally efficient procedure is achieved while keeping accurate predictions of contact points for severe contact scenarios such as sharp curve and turnout negotiations. The use of the proposed hybrid algorithm can eliminate the time-consuming on-line iterative search for the second points of contact. Since the location of the second point of contact is pre-computed by the contact geometry analysis, the occurrence of two-point contact can be predicted by using the look-up table at the one-point contact configuration. A flange climb simulation demonstrates that the proposed hybrid contact search algorithm can be effectively used for modeling wheel/rail contacts in the analysis of general multibody railroad vehicle systems.
Cornering stability improvement by gyro moment for narrow tilting vehicle
Jeffrey Too Chuan Tan,Yitsao Huang,Yoshihiro Suda,Akira Mizuno,Munehisa Horiguchi 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.7
The aim of this work is to improve the cornering stability of narrow tilting vehicle by gyro moment. The proposed approach is to counterbalancethe instability (wheel lifting) caused by the tilt actuator with gyro moment. A four-wheel narrow tilting vehicle is modeled in amultibody dynamics software to conduct two vehicle motion simulations with hard cornering. The objective of Simulation A is to investigatethe gyro moment effects on the vehicle inner wheel load (wheel lifting), and the purpose of Simulation B is to validate the proposedapproach with the improvement of vehicle lateral acceleration (rollover resistance). The simulation results have shown improved stabilitywith no wheel lifting during hard cornering, and higher lateral acceleration. These have proven our proposed approach of applying gyromoment to further improve the cornering stability of narrow tilting vehicles.