Ensemble based traffic light control for city zones using a reduced number of sensors

Rapid advances in computing, sensing and telecommunication technology offer unprecedented opportunities for artificial intelligence concepts to expand their applications in the field of traffic management and control. Our methodology gravitates around a powerful decision-making method: ensemble-based systems. This technique is used to accurately classify the near future traffic conditions and to make efficient decisions for adapting the traffic lights sequences within an urban area to optimize the traffic flows. The proposed approach requires only measurements provided by traffic sensors located along the principal roads entering the zone. This reduced number of sensors are considered to be enough relevant for classifying the near future state of the traffic and moreover, their measurements can be validated through analytical/hardware redundancy. Our methodology is meant to be implemented within the framework of a wireless sensor and actuator network and is confirmed by computer simulation, including normal or abnormal traffic conditions, for the central part of the city of Timisoara-Romania.     

基于巨磁电阻的车位检测技术研究

在户外进行停车场车位检测容易受到不同外界因素的干扰,从而造成不必要的车位信息错误,给停车场的管理和停车用户带来诸多不便。针对这类户外停车场车位检测的实际要求以及对相关车位检测技术的研究,提出以基于巨磁电阻的车位检测技术作为核心检测技术,即汽车在停放或离开车位时使得地磁场与巨磁电阻之间磁场关系发生的变化来判断车位上车辆的变化,并且配套的设计了基于巨磁电阻检测的硬件系统和软件系统,分别用于停车位的车位检测和车位的显示,同时通过对巨磁电阻灵敏度的调节来更加灵活和准确地进行检测。试验结果表明,相比于其他车位检测技术该车位检测技术拥有更高精度和更强稳定性。     

Hydraulic actuation technology for full- and semi-active railway suspensions

The paper describes a simulation study that provides a comprehensive comparison between full-active and semi-active suspensions for improving the vertical ride quality of railway vehicles. It includes an assessment of the ride quality benefits that can theoretically be achieved with idealised devices, and also examines the impact of real devices based upon hydraulic actuation technology.     

Utilisation of optimisation solutions to control active suspension for decreased braking distance

This work deals with how to utilise active suspension on individual vehicle wheels in order to improve the vehicle performance during straight-line braking. Through numerical optimisation, solutions have been found as regards how active suspension should be controlled and coordinated with friction brakes to shorten the braking distance. The results show that, for the studied vehicle, the braking distance can be shortened by more than 1?m when braking from 100?km/h. The applicability of these results is studied by investigating the approach for different vehicle speeds and actuator stroke limitations. It is shown that substantial improvements in the braking distance can also be found for lower velocities, and that the actuator strokes are an important parameter. To investigate the potential of implementing these findings in a real vehicle, a validated detailed vehicle model equipped with active struts is analysed. Simplified control laws, appropriate for on-board implementation and based on knowledge of the optimised solution, are proposed and evaluated. The results show that substantial improvements of the braking ability, and thus safety, can be made using this simplified approach. Particle model simulations have been made to explain the underlying physical mechanisms and limitations of the approach. These results provide valuable guidance on how active suspension can be used to achieve significant improvements in vehicle performance with reasonable complexity and energy consumption.     

On the achievable performance using variable geometry active secondary suspension systems in commercial vehicles

There is a need to further improve driver comfort in commercial vehicles. The variable geometry active suspension offers an interesting option to achieve this in an energy efficient way. However, the optimal control strategy and the overal performance potential remains unclear. The aim of this paper is to quantify the level of performance improvement that can theoretically be obtained by replacing a conventional air sprung cabin suspension design with a variable geometry active suspension. Furthermore, the difference between the use of a linear quadratic (LQ) optimal controller and a classic skyhook controller is investigated. Hereto, an elementary variable geometry actuator model and experimentally validated four degrees of freedom quarter truck model are adopted. The results show that the classic skyhook controller gives a relatively poor performance while a comfort increase of 17–28% can be obtained with the LQ optimal controller, depending on the chosen energy weighting. Furthermore, an additional 75% comfort increase and 77% energy cost reduction can be obtained, with respect to the fixed gain energy optimal controller, using condition-dependent control gains. So, it is concluded that the performance potential using condition-dependent controllers is huge, and that the use of the classic skyhook control strategy should, in general, be avoided when designing active secondary suspensions for commercial vehicles.     

Active control strategy for the running attitude of high-speed train under strong crosswind condition

This paper focuses on the safety of high-speed trains under strong crosswind conditions. A new active control strategy is proposed based on the adaptive predictive control theory. The new control strategy aims at adjusting the attitudes of a train by controlling the new-type intelligent giant magnetostrictive actuator (GMA). It combined adaptive control with dynamic matrix control; parameters of predictive controller was real-time adjusted by online distinguishing to enhance the robustness of the control algorithm. On this basis, a correction control algorithm is also designed to regulate the parameters of predictive controller based on the step response of a controlled objective. Finally, the simulation results show that the proposed control strategy can adjust the running attitudes of high-speed trains under strong crosswind conditions; they also indicate that the new active control strategy is effective and applicable in improving the safety performance of a train based on a host–target computer technology provided by Matlab/Simulink.     

直线电机牵引模式下5号道岔及小半径曲线轨道铺设技术

由于广州轨道交通四号线采用了先进的直线电机运载系统，该系统能够适应小号码道岔和小半径曲线运行。通过在广州轨道交通四号线车辆段对5号道岔及65m的小半径曲线轨道的研究和铺设实践，以及树脂合成轨枕的引进应用，积累了可供今后建设类似工程借鉴的技术和经验。     

应用于触觉传感器的片状铁镓合金材料特性研究

触觉传感器对于推动机器人智能化发展具有重要作用,应用新型智能敏感材料开发先进的触觉传感器势在必行。新型铁镓合金(Fe83Ga17)具有拉伸强度高、延展性好、磁致伸缩大和机电耦合效率高等优点,可作为磁致伸缩触觉传感器的敏感元件。本文利用COMSOL多物理场仿真软件,建立了片状铁镓合金的悬臂梁模型,分析了梁在不同磁场强度和受力时磁感应强度的变化情况。通过对铁镓合金材料特性的测试和探究,确定了其作为磁致伸缩触觉传感器核心换能元件的适用性,为更好的设计和优化磁致伸缩触觉传感器,提高传感器的输出性能奠定了基础。     

磁致伸缩位移传感器在岸桥上的应用

磁致伸缩技术越来越广泛地应用于测控领域,主要介绍磁致伸缩传感器的原理及特点,同时介绍了磁致伸缩传感器在岸桥液压缸位置检测上的应用。     

船用阀门遥控系统综述

简要介绍了目前船用阀门遥控系统的几种主要驱动类型,其构成原理及各自的优缺点,总结了如何根据不同船型的实际需要选择不同的阀门驱动方式,并以液压驱动方式为例介绍了选择系统的基本准则,对用户如何根据实际需要选择合适的阀门遥控系统提出了建议,并对阀门遥控系统的发展趋势进行了展望。