Electronically Controllable Vehicle Suspensions

The basic functions which suspensions must perform are described and categories of controllable suspensions based on the required amount of control power are defined. The kinds of devices which can be used in controllable suspensions are discussed as well as several basic control philosophies. Finally, fundamental theoretical and practical limitations in suspension performance are indicated.     

High-speed rail service: Issues for the Detroit-Chicago corridor

Several issues concerning the implementation and operation of high-speed rail service in the Detroit-Chicago corridor are identified and discussed in this paper. The primary concern is whether such a service is likely to be attractive enough to induce the private sector to provide it. While the outlook for private operation appears pessimistic, consideration of a broader range of potential benefits (e.g., direct and indirect employment) may justify public involvement and investment.     

西班牙Talgo 350型高速动力车头(二)

用于未来西班牙高速铁路商业运营的Talgo 350型准轨高速列车由1台动力车头和6辆Talgo车辆组成.动力车头采用了最新的空气动力学知识,安装了基于列车通信网络TCN的电子控制装置,集成了辅助逆变器的IGBT变流器和半弹性架支式悬挂的横向传动装置.     

A review of the road safety strategy in hong kong

Since the mid-1990s, the effectiveness of road safety measures in Hong Kong has been weakening. Six administrations in Australia, California, Great Britain (GB), Japan, New Zealand and Sweden are selected to help review the road safety activities in Hong Kong. Nine main components of the road safety strategy, including vision, objectives, targets, action plan, evaluation and monitoring, research and development, quantitative modeling, institutional framework and funding are summarized from the road safety strategies of these overseas administrations and compared to that of Hong Kong. It is found that Hong Kong's road safety activities have to be restructured to make significant improvement. In the future, a new approach structured by the nine different road safety components is recommended. The lessons learnt can be generalized to smooth the progress of other administrations at the Intermediate Stage towards the Advanced Stage of road safety development by using the short-, medium- and long-term approaches.     

Estimating salinity to complement observed temperature: 2.Northwestern Atlantic

This paper addresses the problem of estimating salinity for a large region in the Atlantic Ocean containing the Gulf Stream and its recirculation. Together with Part 1 [Thacker, W.C., 2007-this issue. Estimating salinity to complement observed temperature: 1. Gulf of Mexico. Journal of Marine Systems. doi:10.1016/j.jmarsys.2005.06.008.] dealing with the Gulf of Mexico, this reports on the first efforts of a project for developing world-wide capability for estimating salinity to complement expendable-bathythermograph (XBT) data. Such estimates are particularly important for this region, where the strong frontal contrasts render the task of assimilating XBT data into numerical models more sensitive to the treatment of salinity.Differences in salinity's co-variability with temperature and with longitude, latitude, and day-of-year from the northwestern part of the region with the Gulf Stream to the southeastern part more characteristic of the Sargasso sea suggested that the region be partitioned to achieve more accurate salinity estimates. In general, accuracies were better in the southeastern sub-region than in the more highly variable northwestern sub-region with root-mean-square estimation errors of 0.15 psu at 25 dbar and 0.02 psu at 300 dbar as compared with 0.35 psu and 0.50 psu, respectively, but in the southeast there was an unexpected error maximum around 1000 dbar where estimates were slightly less accurate than in the northwest. For pressures greater than 1400 dbar root-mean-square errors in both sub-regions were less than 0.02 psu.     

Optimal handling capacity at a berth

In a recent paper Wanhill [1] described a method for determining the number of berths that should be provided at a port so that the total usage cost would be minimized. However, in many situations a port will provide a single specialized berth to cater for a particular type of cargo; for example, the unloading of iron-ore at a steelworks or the discharge of oil at a general cargo port. The problem then is not one of deciding on the number of berths to be built but rather that of finding the optimal cargo handling capacity for the single berth available. A model is presented in this paper indicating how such a decision may be made, and two examples give approximate lower and upper bounds for the optimal capacity for many practical cases. A second paper will show how a theoretical model often has to be modified in the light of particular circumstances.     

The federal rail transit policy: Rhetoric or reality?

Almost two years ago the U.S. Department of Transportation issued a formal statement of policy on rail transit. The aim of the policy was to articulate more clearly some of the basic principles and philosophy which would guide Federal participation in urban rail transit investment. The paper examines the principal tenets of the policy and assesses its influence on local rail transit development.     

RMS Values for Force, Stroke and Deflection in a Quarter-car Model Active Suspension with Preview

Summary In the case of a quarter-car vehicle model incorporating an active suspension, the addition of preview to the system necessitates finding new techniques for the direct computation of rms values for control force, suspension stroke and tyre deflection on a random road. Here we obtain these rms values from the performance index components as derived analytically by means of matrix operations requiring the solution of Lyapunov equations and the use of similarity transformations. Some numerical examples and MATLAB programs are included.     

Ride Vibration Measurements of Agricultural Tractor and Trailer Combinations

Tractor ride vibration levels have been measured when operating with and without a two wheel (2W) unbalanced and a four wheel (4W) balanced trailer. Measurements were made in the vertical, pitch, longitudinal and roll directions with the trailers unladen and laden over four typical farm surfaces

The results showed that tractor ride vibration levels were usually increased in all directions-particularly the longitudinal direction- when operating with the laden trailers. But for the unladen trailers, they were increased only in the longitudinal direction. Predominant tractor frequencies tended to be lower with the trailers attached, and coupling between the tractor longitudinal, vertical, roll and pitch co-ordinates was generally increased

Comparisons of the results with the trends predicted by a simplified theoretical model of a tractor and 2W trailer, suggested that the model should be extended to include, (a) the roll direction, (b) more realistic ground inputs, and (c) a 4W trailer