Handling Capabilities of Vehicles in Emergencies Using Coordinated AFS and ARMC Systems

In this paper, an advanced control technique that can be implemented in hard emergency situations of vehicles is introduced. This technique suggests integration between Active Front Steering (AFS) and Active Roll Moment Control (ARMC) systems in order to enhance the vehicle controllability. For this purpose, the AFS system applies a robust sliding mode controller (SMC) that is designed to influence the steering input of the driver by adding a correction steering angle for maintaining the vehicle yaw rate under control all the time. The AFS system is then called active-correction steering control. The ARMC system is designed to differentiate the front and rear axles' vertical suspension forces in order to alter the vehicle yaw rate and to eliminate the vehicle roll motion as well. Moreover, the operation of the SMC is based on tracking the behavior of a nonlinear 2-wheel model of 2-DOF used as a reference model. The 2-wheel model incorporates real tire characteristics, which can be inferred by the use of trained neural networks. The results clearly demonstrate the enhanced characteristics of the proposed control technique. The SMC with the assistance of the ARMC provides less correction of the steering angle and accordingly reduces the possibility of occurrence of the saturation phenomenon that is likely to take place in the operation of the SMC systems.     

Age and cross-cultural comparison of drivers’ cognitive workload and performance in simulated urban driving

Driving demands significant psychomotor attention and requires even more when drivers are engaged in secondary tasks that increase cognitive workload and divert attention. It is well established that age influences driving risk. Less is known about how culture impacts changes in attention. We conducted parallel driving simulations in the US and Korea to measure the extent to which age and culture influence dual-task performance. There were 135 participants divided into two groups: a younger group aged 20∼29, and an older group aged 60∼69. Whereas some differences by culture appeared in absolute control measures, the younger participants showed similar mean velocity and compensatory patterns associated with increased cognitive load in the urban setting; however, the results from the older samples were less similar.     

Emissions simulation in a 7000 kg-grade diesel hybrid electric vehicle

Hybrids combine a combustion engine with an electric motor and battery. The two technologies can be combined to reduce fuel consumption and exhaust emissions. This paper presents the concept of hybrid electric vehicles (HEVs) applied to truck or van vehicles with diesel engines. The simulation results from the advanced vehicle simulator (ADVISOR) demonstrate that the required power may be properly shared between the internal combustion engine and electric motor. The simulation can also be used to prove that the technique is useful for improvements in driving performance; additionally, the technique is suitable for hybrid electric vehicles, allowing for good fuel economy and low emissions performance.     

Beyond “Peak Car”: A reflection on the evolution of public sentiment about the role of cars in cities

In this volume, Jones has made a persuasive case for considering recently observed reductions in car use (and sometimes car ownership) in a number of major northern cities as part of an evolutionary process, rather than the consequence of transient conditions such as the economic downturn of 2008 and its relatively slow recovery. In an era bringing new service models for mobility and communications that have important implications for safety, security, the environment and well-being, he points to the role of public attitudes and sentiments that may underlie changing policy priorities and an associated culture change with respect to transport in cities and the reclamation of street space. This paper briefly explores the role of public sentiments and reflects on the apparent emergence of a popular subculture that favors living, if possible, without owning or using cars, in contrast to older subcultures embracing more extreme sentiments that are either Car-centered or emphatically anti-car.     

Circuit racing,track texture,temperature and rubber friction

ABSTRACT

Some general observations relating to tyre shear forces and road surfaces are followed by more specific considerations from circuit racing. The discussion then focuses on the mechanics of rubber friction. The classical experiments of Grosch are outlined and the interpretations that can be put on them are discussed. The interpretations involve rubber viscoelasticity, so that the vibration properties of rubber need to be considered. Adhesion and deformation mechanisms for energy dissipation at the interface between rubber and road and in the rubber itself are highlighted. The enquiry is concentrated on energy loss by deformation or hysteresis subsequently. Persson's deformation theory is outlined and the material properties necessary to apply the theory to Grosch's experiments are discussed. Predictions of the friction coefficient relating to one particular rubber compound and a rough surface are made using the theory and these are compared with the appropriate results from Grosch. Predictions from Persson's theory of the influence of nominal contact pressure on the friction coefficient are also examined. The extent of the agreement between theory and experiment is discussed. It is concluded that there is value in the theory but that it is far from complete. There is considerable scope for further research on the mechanics of rubber friction.     

ASNE Delaware Valley Chapter Teaches Students Naval Engineering through the Sea Perch Underwater Robotics Program

Sea Perch is an underwater robotics program sponsored by the Office of Naval Research as part of the National Naval Responsibility for Naval Engineering aimed at recruiting the next generation of naval architects and marine engineers. ASNE Delaware Valley (DV) and Naval Surface Warfare Center, Philadelphia, embraced the outreach opportunity as an educational, challenging, and fun way to get kids excited about naval engineering. ASNE-DV has received an overwhelmingly positive feedback from both teachers and students. Teachers have said their students are excited to learn about remotely operated vehicles and cannot wait to work on their Sea Perch robots. During the past 3 years, ASNE-DV has teamed with Drexel University and the school district of Philadelphia to successfully implement a sustainable, local Sea Perch competition program for middle and high school students. ASNE-DV is encouraging expansion of the program to additional areas. This article discusses how the DV Sea Perch program evolved from two schools building the robots in the winter of 2005, to over 40 teams from a diverse range of schools participating in a Sea Perch competition in the spring of 2007.     

新转化膜在汽车行业内的应用近况

1 引言 伴随着20世纪初Thomas Coslett及其他众多人士的研究工作,在1943年引入了Jernstadt磷酸盐后,诞生了今天人们所熟知的用于镀锌工艺前预浸处理的含钛磷酸氢二钠溶液.使用该磷酸盐后,可以更快地形成更为细小的磷酸锌晶体组织.过去60多年间,这种基础工艺在众人的努力下愈发精细,但是基本的化学特性及功能仍然保持不变.     

Tractor-Semitrailer Dynamics: Design of the Fifth Wheel*

The nonlinear equations of motion are derived for a tractor-semitrailer truck where both the itractor and the semitrailer yaw, pitch, roll, and translate. Special emphasis is placed on the constraints imposed by the fifth wheel on the vehicle motion. In particular, the effects of two proposed fifth wheel design changes on the jackknifing behavior of a vehicle in a turning, braking maneuver are studied. The results demonstrate that the tendency of the vehicle to jackknife can be reduced with a geometric modification of the fifth wheel.     

Energy Dissipation Due to Vehicle/Track Interaction

The effects of track irregularities and wheel profile on the amount of energy dissipated in railroad freight vehicles is examined. A nonlinear computational model is used to determine the average dissipation in the vehicle suspension and the wheel/rail contact patches. This dissipation is a component of the total resistance force acting on the vehicle. Parametric results are presented showing the effects of track geometry, wheel profile, suspension design, and hunting on train resistance. Track geometry studies consider the effects of track quality and curving. The AAR 1:20 wheel profile and the Heumann wheel profile are compared under various operating conditions. Compared with the Heumann profile, the AAR 1:20 profile is shown to have lower average resistance on good quality tangent track, but higher average resistance in steady curves. A trade-off exists between the two profiles when dynamic curve entry is considered.     

移动电站备件库存优化分析

建立了备件库存物资的存储策略模型，并通过建立存储策略期望费用方程，求解期望费用的极小值，来确定期初存储量和订货量。并且计算订货监测点的值，从而建立适宜的备件经济订货模型。