Roll Dynamics of Commercial Vehicles

An analytical model is developed here for studying the roll dynamics of commercial vehicles. Large displacements and rotations are accounted for in this nonlinear model so that it can be used for the study of roll dynamics well beyond the limits of wheel lift-off. The model is used to illustrate some of the dynamic phenomena in vehicle rollover, especially the interactive coupling between the roll and the vertical modes of motion. The influence of suspension backlash on rollover resistance is demonstrated, and the phenomenon of roll motion resonance is illustrated to suggest new means for evaluating vehicle rollover sensitivity.     

The dynamic relationships between paper petroleum refining and physical trade of crude oil into the United States

This article examines the relationship between refinery margins traded on paper using petroleum futures (the paper refinery) and the physical trade of crude oil into the US. Computations of a 3:2:1 crack spread were constructed using daily observations of second- and third-nearby unleaded gasoline and heating oil futures contracts traded on the New York Mercantile Exchange (NY MEX) and spot Brent crude oil prices. The crack spread represents the margin between the cost of crude oil feed stock today and the value of the products produced by a refinery in the future. Unit root tests on each of the time series found crack spreads to be stationary while crude oil imports were found to be non-stationary. A s the two series were found to be integrated of different order, cointegration analysis of the two series was not deemed appropriate. Instead, linear relationships between crack spreads and imports were examined using causality tests. It was found that the 2-month 3:2:1 crack spread Granger-causes crude oil imports and that this causality is unidirectional. The significance of these findings lies in the fact that other industries like tanker shipping derive their demand from the demand for, and trade in, petroleum. Crack spreads, therefore, can provide a leading indicator for short term developments in tanker demand. For a chartering manager who has ships on the spot market, crack spreads can help him/her anticipate demand developments and influence vessel deployment and chartering decisions.     

模糊控制技术在船舶动力定位中的应用研究

在进行某船动力定位系统的设计过程中,采用了模糊控制器作为系统的控制器,并针对仿真过程中出现的问题进行优化,得到了一个切实可行的模糊控制器,并对该模糊控制器进行了仿真试验验证。     

起重机仿真训练器的研制与应用

通过对国内外港口装卸机械司机的培训状况分析,论述了在我国研制和应用计算机仿真训练器的现实意义和效益,提出了计算机仿真训练器的初步方案,并对其功能,结构和工作原理作了说明。     

坞门吊装吊索受力计算

本文以定距双吊钩起吊门为例,在考虑偏心的情况下,提出了一套有针对性的计算方法,并对吊索内力计算结果、现场实测结果和不同的计算方法做了分析比较。     

肥大型浅吃水船舶的模型试验

考虑沿海运输船舶进江和降低运输成本的需要，对于优化的超浅吃水（Ｂ／Ｔ＝４．０）肥大型（ＣＢ＝０．８４）船型，给出了快速性的试验和耐波性的计算分析结果，以供船舶设计参考。     

深基坑支护结构变形预测研究与应用

利用现场监测的深基坑支护结构变形信息资料 ,结合参数优化反分析土体m值 ,根据现场地质资料和优化后的参数 ,通过有限元计算对深基坑支护系统进行变形预测 ,及时调整开挖方案和支护参数 ,此方法可以有效的指导基坑施工 ,确保施工安全     

动车组车载通信设备维护工作探讨

根据我国铁路车载设备维修方式,以及对维修人员的岗位分析,对动车组车载通信设备的维修工作进行了讨论,并提出了积极的建议.     

An adaptive lateral preview driver model

Successful modelling and simulation of driver behaviour is important for the current industrial thrust of computer-based vehicle development. The main contribution of this paper is the development of an adaptive lateral preview human driver model. This driver model template has a few parameters that can be adjusted to simulate steering actions of human drivers with different driving styles. In other words, this model template can be used in the design process of vehicles and active safety systems to assess their performance under average drivers as well as atypical drivers. We assume that the drivers, regardless of their style, have driven the vehicle long enough to establish an accurate internal model of the vehicle. The proposed driver model is developed using the adaptive predictive control (APC) framework. Three key features are included in the APC framework: use of preview information, internal model identification and weight adjustment to simulate different driving styles. The driver uses predicted vehicle information in a future window to determine the optimal steering action. A tunable parameter is defined to assign relative importance of lateral displacement and yaw error in the cost function to be optimized. The model is tuned to fit three representative drivers obtained from driving simulator data taken from 22 human drivers.