An overview: modern techniques for railway vehicle on-board health monitoring systems

Health monitoring systems with low-cost sensor networks and smart algorithms are always needed in both passenger trains and heavy haul trains due to the increasing need for reliability and safety in the railway industry. This paper focuses on an overview of existing approaches applied for railway vehicle on-board health monitoring systems. The approaches applied in the data measurement systems and the data analysis systems in railway on-board health monitoring systems are presented in this paper, including methodologies, theories and applications. The pros and cons of the various approaches are analysed to determine appropriate benchmarks for an effective and efficient railway vehicle on-board health monitoring system. According to this review, inertial sensors are the most popular due to their advantages of low cost, robustness and low power consumption. Linearisation methods are required for the model-based methods which would inevitably introduce error to the estimation results, and it is time-consuming to include all possible conditions in the pre-built database required for signal-based methods. Based on this review, future development trends in the design of new low-cost health monitoring systems for railway vehicles are discussed.     

Proposal for Testing and Rating of Traction and Stability Control Systems

Function and object of existing control systems for traction and stability are described. The problem of rating and objective evaluation of the influence of such slip control systems on vehicle dynamics is demonstrated. Closed-loop manoeuvres with subjective assessment and open-loop tests with measured data are shown. Analysis of correlation results in characteristic values which allow assessment of dynamic performance of slip control systems. Tests on natural and synthetic μ-low road surface with two passenger cars, equipped with different slip control systems, demonstrate the objective test method and show their results.     

Human-Centered Design of an Acc-With-Braking and Forward-Crash-Warning System

This paper addresses the development of driver assistance systems whose functional purposes are to provide both adaptive cruise control (ACC) and forward collision warning (FCW). The purpose of the paper is to combine concepts from human factors psychology, vehicle-dynamics, and control theory, thereby contributing to the body of knowledge and understanding concerning human-centered approaches for designing and evaluating driver assistance systems. Conceptual and experimental results pertaining to driving manually and with the assistance of ACC and FCW are presented. The following human-centered aspects of driver-assistance systems are analyzed and presented: the looming effect; including rule-based and skill-based behavior in the design of ACC systems; using desired dynamics in controlling the driving process; braking rules that trade headway range for deceleration level; and collision-warning rules based on two different stress indicators. Field-test data are examined to justify and verify the parametric values selected for use in human-centered ACC systems. Measured data from on-road driving are used to evaluate the performance of proposed FCW systems in braking situations. The paper concludes with observations concerning the difficulty of developing a clear understanding of when and why drivers brake.     

Human-Centered Design of an Acc-With-Braking and Forward-Crash-Warning System

This paper addresses the development of driver assistance systems whose functional purposes are to provide both adaptive cruise control (ACC) and forward collision warning (FCW). The purpose of the paper is to combine concepts from human factors psychology, vehicle-dynamics, and control theory, thereby contributing to the body of knowledge and understanding concerning human-centered approaches for designing and evaluating driver assistance systems. Conceptual and experimental results pertaining to driving manually and with the assistance of ACC and FCW are presented. The following human-centered aspects of driver-assistance systems are analyzed and presented: the looming effect; including rule-based and skill-based behavior in the design of ACC systems; using desired dynamics in controlling the driving process; braking rules that trade headway range for deceleration level; and collision-warning rules based on two different stress indicators. Field-test data are examined to justify and verify the parametric values selected for use in human-centered ACC systems. Measured data from on-road driving are used to evaluate the performance of proposed FCW systems in braking situations. The paper concludes with observations concerning the difficulty of developing a clear understanding of when and why drivers brake.     

电子地图汽车导向系统

介绍了汽车导向行驶系统的分类,电子地图汽车导向系统的应用和使用注意事项。     

New approaches to enhance active steering system functionalities: preliminary results

An important development of the steering systems in general is active steering systems like active front steering and steer-by-wire systems. In this paper the current functional possibilities in application of active steering systems are explored. A new approach and additional functionalities are presented that can be implemented to the active steering systems without additional hardware such as new sensors and electronic control units. Commercial active steering systems are controlling the steering angle depending on the driving situation only. This paper introduce methods for enhancing active steering system functionalities depending not only on the driving situation but also vehicle parameters like vehicle mass, tyre and road condition. In this regard, adaptation of the steering ratio as a function of above mentioned vehicle parameters is presented with examples. With some selected vehicle parameter changes, the reduction of the undesired influences on vehicle dynamics of these parameter changes has been demonstrated theoretically with simulations and with real-time driving measurements.     

北京市交通信号管理与控制平台设计及应用

在分析现有交通信号系统的特性以及存在问题的基础上,以对现有信号系统进行有效整合、综合利用交通流数据、提高交通信号控制的管理水平为目标,设计了1种集成的交通信号控制平台,并给出了平台在北京市交通信号管理与控制系统中的应用。     

基于粗集理论的交通控制系统研究

为满足智能交通系统高性能模糊控制器设计的需要,把粗集理论融入常规的模糊推理,提出了一种交通控制模糊建模新方法,利用粗集理论的知识推理,直接从交通系统的测量数据提取模糊规则,解决了城市交通模糊控制规则提取的瓶颈问题。实例分析表明:该方法简单有效,不仅可以最大限度地减少从交警的经验直接提取模糊规则的局限性,以获取最优的模糊模型,同时建模方法具有普遍适用性,提取的模糊规则更具客观性。该方法可以推广应用于多交叉口的模糊协调控制,对于采用复杂算法的控制系统更能显示出其优越性。     

车身焊装激光在线检测系统的柔性标定方法

激光在线检测设备的全局标定是在线测量的基础。针对汽车生产线上车身的激光检测系统，探讨了检测系统的各种在线标定方法，在分析、对比了各种全局标定方法在实际运用过程中的标定精度和可靠性的基础上，提出了利用柔性较大的便携式6轴关节式三坐标测量机(PCMM)对激光在线检测系统进行在线全局标定的方法，并通过在线标定实例证明了其可行性。     

Advanced Control Methods for Automotive Applications

This paper reviews key developments in applications of advanced control methods to automotive systems. Such applications appear in many aspects of vehicle controls. We will examine representative application areas, which include engines, suspension systems, traction systems, steering systems and those for automated highway systems (AHS). Each area is examined from the viewpoint of modeling and control algorithm development. Useful control theories for automotive application are briefly reviewed for better understanding of the applicability of these theories.     

Expanding transmission capacity of can systems using dual communication channels with kalman prediction

The controller area network (CAN) protocol is widely used for in-vehicle network (IVN) systems, and many automotive companies also use the CAN in chassis network systems. However, the increasing number of electronic control units (ECUs) dictated by the need for more intelligent and fuel-efficient functions requires an IVN system with a greater transmission capacity and less network delay. Automotive companies have tried several approaches such as segmenting CAN systems and developing time-triggered protocols. This paper presents a practical method for increasing the transmission capacity and reducing the network delay in CAN systems using dual communication channels with a traffic-balancing algorithm based on Kalman prediction to forecast the traffic on each channel and allocate frames to the one that is most appropriate. An experimental testbed using commercial microcontrollers with two or more CAN protocol controllers was used to demonstrate the feasibility of the Kalman traffic-balancing algorithm. Experimental results show that the traffic-balancing CAN system with Kalman prediction reduced the transmission delay of all priority messages compared to that of a simple method, such as a channel-switching CAN, without sacrificing the performance for high-priority messages.     

Literature review and fundamental approaches for vehicle and tire state estimation*

ABSTRACT

Most modern day automotive chassis control systems employ a feedback control structure. Therefore, real-time estimates of the vehicle dynamic states and tire-road contact parameters are invaluable for enhancing the performance of vehicle control systems, such as anti-lock brake system (ABS) and electronic stability program (ESP). Today's production vehicles are equipped with onboard sensors (e.g. a 3-axis accelerometer, 3-axis gyroscope, steering wheel angle sensor, and wheel speed sensors), which when used in conjunction with certain model-based or kinematics-based observers can be used to identify relevant tire and vehicle states for optimal control of comfort, stability and handling. Vehicle state estimation is becoming ever more relevant with the increased sophistication of chassis control systems. This paper presents a comprehensive overview of the state-of-the-art in the field of vehicle and tire state estimation. It is expected to serve as a resource for researchers interested in developing vehicle state estimation algorithms for usage in advanced vehicle control and safety systems.     

高速公路隧道照明系统节能设计探讨

针对高速公路隧道照明系统的节能需求和系统设计现状,提出高速公路隧道照明系统节能设计在设计参数选用、硬件系统构成、控制方案选用以及营运管理、维护等方面的建议及对策,以期在满足规范的要求下,既满足节能要求,又降低工程造价和营运维护成本.     

轮式工程车辆两种转向方式的对比分析

轮式工程车辆的转向系统要求能够灵活地转向行驶,应避免轮子的滑移或侧滑。常见的工程车辆有两种转向方式,通过对两种转向运动形式进行详细的运动和动力学分析,提出它们的使用范围,并对这两种转向方式的轮式车辆提出应该重视的技术问题及措施。     

H2 optimal control of disturbance-delayed systems with application to vehicle suspensions

Optimal control of systems with time delays among disturbances, such as vehicle suspensions, is a relatively simple but long-standing problem in time-delayed control. We consider the exact H₂ optimal control of systems with time-delayed disturbances and develop a computationally efficient approach for controller synthesis. We extend the Lyapunov-based H₂ norm computation to systems with time-delayed disturbances and then derive a concise formula to explicitly evaluate the sensitivity of the system H₂ norm with respect to controller gains. Thence, a set of necessary conditions for H₂ optimal control of such systems using static output feedback are obtained in the form of algebraic equations. Gradient-based methods are adapted to optimize the controller gains. The method is also extended to reduced-order and decentralized control. As an application, a passive suspension system for an eight-DOF four-wheel vehicle is designed via structured H₂ optimization. The results are compared with those of a design based on a Pade expansion for the time delays and a design obtained by neglecting the disturbance delays.     

Influence of AC system design on the realisation of tractive efforts by high adhesion locomotives

The main task for heavy haul railway operators is to reduce the cost of exported minerals and enhance the long-term viability of rail transport operations through increasing productivity by running longer and heavier trains. The common opinion is that this is achievable by means of implementation of high adhesion locomotives with advanced AC traction technologies. Modern AC high adhesion locomotives are very complex mechatronic systems and can be designed with two alternative traction topologies of either bogie or individual axle controls. This paper describes a modelling approach for these two types of AC traction systems with the application of an advanced co-simulation methodology, where an electrical system and a traction algorithm are modelled in Matlab/Simulink, and a mechanical system is modelled in a multibody software package. Although the paper concentrates on the analysis of the functioning for these two types of traction control systems, the choice of reference slip values also has an influence on the performance of both systems. All these design variations and issues have been simulated for various adhesion conditions at the wheel–rail interface and their influence on the high traction performance of a locomotive equipped with two three-axle bogies has been discussed.     

Longitudinal train dynamics: an overview

This paper discusses the evolution of longitudinal train dynamics (LTD) simulations, which covers numerical solvers, vehicle connection systems, air brake systems, wagon dumper systems and locomotives, resistance forces and gravitational components, vehicle in-train instabilities, and computing schemes. A number of potential research topics are suggested, such as modelling of friction, polymer, and transition characteristics for vehicle connection simulations, studies of wagon dumping operations, proper modelling of vehicle in-train instabilities, and computing schemes for LTD simulations. Evidence shows that LTD simulations have evolved with computing capabilities. Currently, advanced component models that directly describe the working principles of the operation of air brake systems, vehicle connection systems, and traction systems are available. Parallel computing is a good solution to combine and simulate all these advanced models. Parallel computing can also be used to conduct three-dimensional long train dynamics simulations.     

Advanced Control Methods for Automotive Applications

SUMMARY

This paper reviews key developments in applications of advanced control methods to automotive systems. Such applications appear in many aspects of vehicle controls. We will examine representative application areas, which include engines, suspension systems, traction systems, steering systems and those for automated highway systems (AHS). Each area is examined from the viewpoint of modeling and control algorithm development. Useful control theories for automotive application are briefly reviewed for better understanding of the applicability of these theories.     

现代汽车安全舒适便捷系统综述

安全、舒适和便捷的电控系统广泛地应用在汽车技术中,不同的汽车厂对此方面的配置也各有不同。本文以雅阁为例,对现有的汽车安全、舒适和便捷系统作了归纳,并对未来的发展给予展望。     

摩托车音响系统的设计探析

多方面分析表明,在摩托车上加装音响系统是可行的,并根据实际情况提出了在摩托车上加装音响系统的设计原则和配置、安装型式.