城市快速路与地面道路交通整合控制分析

阐述了城市快速路与普通城市道路交通整合控制的必要性,叙述了国内外研究者提出的比较成熟的匝道控制方法及匝道与地面交通整合控制方法,提出了以城市快速路主线流量与匝道流量之和应小于合流处通行能力、主线车辆占有率应小于最佳占有率、速度约束以及普通城市道路地面交叉口的最大排队长度应小于路段长度为匝道控制约束条件;提出了以通过城市快速路系统和地面交叉口的总旅行时间最小为优化目标函数,实现城市快速路与普通道路的上、下匝道整合控制,以取得最优的城市综合交通系统效益.     

浅析企业内部控制

经过三十多年的改革实践,我国的企业家们越来越感到强化企业内部控制与管理的重要性,同时也在积极探索如何才能加强内部控制与管理。内部控制的理念逐渐被企业界所关注,这一工作虽已取得成效,但是在企业不断革新、不断迎接市场挑战的形势下,我国企业的内部控制工作仍处于起步阶段,而发达国家已经研究和总结出了一套比较完整的理论和方法——三大目标和五大组成部分：从＂控制环境、风险评估、控制活动、信息与交流和监督评审＂等五方面开展工作,为实现各项＂操作性目标、信息性目标和遵从性目标＂而自觉奋斗。本文对国外先进的内部控制理论和方法以及相关理论进行简要分析,希望对我国企业的内部控制机制的建立和完善有所助益。     

汽车尾气排放控制技术的分析与研究

介绍了国内外汽车排放造成的污染状况与控制技术的产生，国内外汽车尾气转化器的应用情况与发展趋势。     

汽车动力学稳定性自适应控制研究

在车辆二自由度分析模型的基础上，设计了基于单神经元控制器的自适应控制系统，对控制性能进行了仿真，并与常规PID控制作了对比分析，结果表明，自适应控制有利于改善系统的控制性能。     

中外信号控制环形交叉口控制模式的对比研究

信号控制环形交叉口是大流量环形交叉口一种理想的交通控制方式,在国内外得到广泛的应用并取得很好的运行效果。我国由于缺少现代环形交叉口的充分发展与应用,所以导致信号控制环形交叉口的控制模式与国外不尽相同。本文从信号控制环形交叉口的起源与发展着手,对各种信号控制环形交叉口的优缺点进行比较,分析各自的适用范围,探究造成中外环形交叉口信号控制模式异同的原因,最后总结国外的经验与教训,提出我国信号控制环形交叉口健康发展相应的对策。     

混凝土裂缝与坍塌的质量控制

从施工角度对混凝土裂缝、坍塌问题进行了分析，总结了操作性较强的控制措施，提出了综合控制混凝土裂缝与坍塌的建议。     

新型的动力转向系统

国外生产的高档轿车引入了按车速与转向盘转速自动变助力的动力转向条件－－变助力的液压转向系统或电子控制助力转向系统，本文对这两种新型系统的特点，结构，工作原理进行了介绍。     

汽车电子技术面面观

电子技术在汽车上首先应用于发动机燃油消耗控制与排放控制,接着被应用于底盘部分的控制。以提高行驶的稳定性、安全性与舒适性等。随着交通运输向高密度方向发展,电子技术也被广泛应用于改善汽车性能和环境的各个方面。 发动机电子控制技术 该技术包括燃油喷射控制、电子点火控制、怠速控制、进气控制、排放控制、增压控制、发动机爆震控制和     

沥青路面施工中混合料离析及压实的控制技术

讨论了沥青路面施工控制技术中存在的问题，分析其产生的不良后果和原因，提出了解决的工艺措施与措施技术。     

大节段吊装焊接钢箱梁斜拉桥线形与索力控制分析

文章结合青岛海湾大桥工程红岛航道桥的施工控制经验,探讨采用大节段吊装与焊接施工的钢箱梁斜拉桥在线形与索力控制时的方法及所应注意的问题,为同类型桥梁的分析与控制提供借鉴。     

Nonlinear optimal integrated vehicle control using individual braking torque and steering angle with on-line control allocation by using state-dependent Riccati equation technique

This paper proposes the solution of state-dependent Riccati equation as a nonlinear optimal regulator to stabilise the motion dynamics of the vehicle model subjected to sudden disturbance inputs in the lateral direction. The proposed nonlinear regulator coordinates individually actuated wheel braking torque and steering wheel angle simultaneously in an optimal manner. Performance criteria are satisfied by solving the Riccati equation based on the given cost function subjected to the nonlinear vehicle dynamics. On-line control allocation in terms of optimal brake torque distribution enhanced by optimal wheel steering angle input is achieved. Furthermore, the proposed optimal nonlinear regulator is an active fault-tolerant control system against partial by-wire actuator failures while guaranteeing stability with good performance due to its capability to allocate the individual control inputs in an optimal way. The main aim is to stabilise the motion dynamics of the vehicle model during short-term emergency situations along the desired straight trajectory manageable by average drivers and to provide vehicle stability and handling predictability through the interaction of individual wheel braking and steering actuators. Simulation results are used to illustrate the effectiveness of the proposed methodology.     

Vehicle dynamic control of a passenger car applying flexible body model

Modern software tools have enhanced modelling, analysis and simulation capabilities pertaining to control of dynamic systems. In this regard, in this paper a full vehicle model with flexible body is exposed by using MSC. ADAMS and MSC. NASTRAN. Indeed, one of the most significant vehicle dynamic controls is directional stability control. In this case, the vehicle dynamic control system (VDC) is used to improving the vehicle lateral and yaw motions in critical manoeuvres. In this paper, for design the VDC system, an optimal control strategy has been used for tracking the intended path with optimal energy. For better performance of VDC system, an anti-lock brake system (ABS) is designed as a lower layer of the control system for maintaining the tyre longitudinal slip in proper value. The performances of the controller on rigid and flexible models are illustrated, and the results show the differences between the control efforts for these models, which are related to the differences of dynamic behaviours of rigid and flexible vehicle dynamic models.     

Optimal motion control for collision avoidance at Left Turn Across Path/Opposite Direction intersection scenarios using electric propulsion

Collision avoidance at intersections involving a host vehicle turning left across the path of an oncoming vehicle (Left Turn Across Path/Opposite Direction) have been studied in the past, but mostly using simplified interventions and rarely considering the possibility of crossing the intersection ahead of a bullet vehicle. Such a scenario where the driver preference is to avoid a collision by crossing the intersection ahead of a bullet vehicle is considered in this work. The optimal vehicle motion for collision avoidance in this scenario is determined analytically using a particle model within an optimal control framework. The optimal manoeuvres are then verified through numerical optimisations using a two-track vehicle model, where it was seen that the wheel forces followed the analytical global force angle result independently of the other wheels. A Modified Hamiltonian Algorithm controller for collision avoidance that uses the analytical optimal control solution is then implemented and tested in CarMaker simulations using a validated Volvo XC90 vehicle model. Simulation results showed that collision risk can be significantly reduced in this scenario using the proposed controller, and that more benefit can be expected in scenarios that require larger speed changes.     

四轮转向汽车自适应模型跟踪控制研究

使用单点预瞄驾驶员模型，针对确定性汽车模型探讨了４ＷＳ汽车在单移线行驶过程中后轮的最优转向控制规律。通过引入状态反馈，改善了整车的转向特性，将实际汽车的前后轮胎侧刚度及外界干扰视为有界的不确定性参数，采用自适应模型跟踪变结构控制方法，使得不确定的实际汽车模型能够很好地跟踪确定的最优理论模型，仿真结果表明该方法的可行性，控制系统能够有效地克服参数摄动及外界干扰对系统稳定性的影响。     

Time-optimal control of the race car: a numerical method to emulate the ideal driver

A numerical method for the time-optimal control of the race car is presented. The method is then used to perform the role of the driver in numerical simulations of manoeuvres at the limit of race car performance. The method does not attempt to model the driver but rather replaces the driver with methods normally associated with numerical optimal control. The method simultaneously finds the optimal driven line and the driver control inputs (steer, throttle and brake) to drive this line in minimum time. In principle, the method is capable of operation with arbitrarily complex vehicle models as it requires only limited access to the vehicle model state vector. It also requires solution of the differential equation representing the vehicle model in only the forward time direction and is hence capable of simulating the full vehicle transient response.     

A theoretical justification of the sine with dwell manoeuvre

The sine with dwell (SWD) manoeuvre has received much attention within the context of vehicle stability testing. This manoeuvre is used in a test developed by the NHTSA, designed to certificate electronic stability control systems in light vehicles. The test is used in legislations as well as in consumer tests all over the globe. The SWD manoeuvre was designed using test vehicles on a test track and experimentally validated. The paper at hand uses optimal control theory to theoretically justify the use of the SWD manoeuvre to produce a severe lateral motion and over-steering based on steering input. It is shown that a manoeuvre similar to the SWD manoeuvre can be obtained from an optimal control problem using simple vehicle dynamics models. The optimal control method is further used to analyse the manoeuvre's robustness with respect to vehicle dimensions and tyre properties. It is shown that the manoeuvre is robust in dimensions, which theoretically motivates its application for various sizes of vehicles.     

基于主动安全的轮间电控限滑差速器控制方法研究

论述了电控限滑差速器(ELSD)改善汽车动力学特性的原理,提出了基于提高汽车主动安全性的控制方法。该方法利用前馈与误差反馈控制相结合来控制车辆运动状态。反馈系数根据最优控制的方法确定。通过对所述控制系统的仿真研究,证明该系统在各种路面条件下均可明显改善汽车的操纵稳定性与主动安全性。     

基于驾驶员行为模拟的ACC控制算法

基于驾驶员最优预瞄加速度模型建立了一种适用于多种典型行驶工况的ACC控制算法。该算法采用基于多目标模糊决策方法的驾驶安全性、工效性、轻便性与合法性评价指标以及基于预瞄跟随理论的微分校正函数，描述了ACC控制系统对自由工况、跟随工况和切入工况等不同行驶条件及汽车动力学系统强非线性特性的考虑。     

基于非线性模型预测控制的车辆纵向队列协调控制

本文中针对基于分层控制结构的车辆队列上、下层控制缺少联系的问题,提出了车辆队列跟驰与个体车辆动力学稳定性协调控制的思路,其基本思想是在保证队列中个体车辆安全稳定行驶的同时,尽可能实现队列跟驰控制的目标。基于非线性模型预测控制(nonlinear model predictive control,NMPC)方法设计了车辆队列协调控制方案,设计了包括跟驰间距误差、跟驰速度误差以及车速与车轮圆周速度差3个子目标的优化目标函数,将队列跟驰与车辆动力学稳定性的协调控制转化为约束优化控制问题;基于序列二次规划(sequential quadratic programming,SQP)方法进行求解,得到车辆前、后轴的制动/驱动力矩来实现上层决策输出的期望跟驰加速度。基于由3车辆组成的非线性队列模型对控制方案进行了仿真分析,结果表明,所提出的基于NMPC的车辆队列协调控制策略可以在大范围操纵工况下,在保证车辆安全稳定行驶的基础上实现队列的跟驰控制。     

Optimal preview game theory approach to vehicle stability controller design

Dynamic game theory brings together different features that are keys to many situations in control design: optimisation behaviour, the presence of multiple agents/players, enduring consequences of decisions and robustness with respect to variability in the environment, etc. In the presented methodology, vehicle stability is represented by a cooperative dynamic/difference game such that its two agents (players), namely the driver and the direct yaw controller (DYC), are working together to provide more stability to the vehicle system. While the driver provides the steering wheel control, the DYC control algorithm is obtained by the Nash game theory to ensure optimal performance as well as robustness to disturbances. The common two-degrees-of-freedom vehicle-handling performance model is put into discrete form to develop the game equations of motion. To evaluate the developed control algorithm, CarSim with its built-in nonlinear vehicle model along with the Pacejka tire model is used. The control algorithm is evaluated for a lane change manoeuvre, and the optimal set of steering angle and corrective yaw moment is calculated and fed to the test vehicle. Simulation results show that the optimal preview control algorithm can significantly reduce lateral velocity, yaw rate, and roll angle, which all contribute to enhancing vehicle stability.