基于CarSim的车辆自适应巡航仿真与试验研究

利用CarSim/Simulink联合仿真方法建立了某试验样车的车辆动力学仿真模型,通过对标试验验证了仿真模型与样车的一致性;基于验证后的仿真模型设计并开发了自适应巡航仿真控制器并进行了车辆自适应巡航仿真试验;将仿真控制器移植到自主研发的车辆自适应巡航电控系统并进行实车试验并取得初步效果。     

基于模糊理论的汽车智能巡航控制策略与仿真

基于模糊控制和模型匹配理论,应用分层式汽车智能巡航控制策略,实现节气门和制动踏板的协调控制。模糊上位控制器以实际距离与理想距离差和前方车辆与巡航车速度差作为输入,结合设计的模糊规则,获得巡航车期望加速度。考虑车辆系统干扰和响应延时性影响,构建了模型匹配下位控制器以确保巡航车期望加速度的实际输出。利用Simulink对控制功能实施了仿真验证,结果表明,该控制策略可有效实现智能跟随和定速巡航功能,提高行驶安全性。     

城市工况巡航控制方法及仿真分析

为了提高汽车行驶的安全性和驾驶汽车的舒适性,提出基于城市工况的模糊巡航控制方法,依据巡航控制系统原理建立模糊控制器和汽车纵向系统动力学模型,以理想安全距离与实际距离的差值、两车速度差作为巡航控制系统的控制变量,在Matlab/simulink平台上建立模糊控制器模型、车辆纵向系统动力学模型,最后以一种典型城市道路工况作为仿真工况。仿真结果表明:所建立的模型很好地实现了基于城市工况的安全行驶,具有较好的控制效果,验证了所建模型的有效性和正确性。     

具有量化误差反馈的车辆纵向跟随控制

针对自动跟随车辆间信息传输存在无线网络量化误差的情况,研究了车辆跟随系统的纵向控制问题.假定每个跟随车辆能够通过无线网络获得相邻车辆及领头车辆的状态信息,并且信息在对数量化器传输下存在量化误差.基于车辆非线性纵向动力学耦合模型和车辆固定间隔跟随策略,应用向量Lyapunov函数方法得出的指数稳定性判据,将量化误差处理为系统状态的不确定性,给出补偿量化误差的滑模控制律,并设计满足系统群稳定性的控制器参数.仿真结果表明:相较于不考虑量化误差的控制器,本控制器能够显著提高车辆跟随误差的收敛速度,确保了自动车辆纵向跟随系统的稳定性.     

走-停巡航系统分层控制器设计

结合驾驶统计模型，设计了走一停自适应巡航系统的纵向车间距离控制器。上位控制器的设计与车辆模型无关。在建立目标性能函数的基础上得到控制律；而下位控制器则将油门和制动控制独立设计，依据一定的切换逻辑使它们分别作用于车辆。在制动控制的设计中引入了改进型史密斯预估器。在多种工况下的仿真试验中表明控制器性能良好。     

起停控制策略对整车油耗及排放的影响

介绍了几种混合动力模式的特点,对起停系统的构成和零部件进行分析;建立起停控制系统起动过程的动力学方程,描述了起停系统的工作模式;在AVL Cruise仿真软件中对4种工作循环进行工况油耗的仿真计算;在NEDC循环中对带与不带起停控制系统的整车进行国Ⅳ排放和油耗的测试.实车试验结果表明,仿真模型准确;加装了起停系统的车辆排放性能基本与不带起停系统车辆相当,而其油耗水平则有较大改善.     

无级变速汽车速度巡航模糊控制器的研究

为开发无级变速汽车的车速巡航自动控制系统，本文建立了汽车直线行驶的动态模型，设计了控制系统的模糊控制器，并对控制器在系统的时变参数和变外界负荷情况下的稳定性进行了仿真分析。仿真结果表明，模糊控制器具有良好的性能，具实用价值。     

基于安全距离模型的车辆跟随控制策略研究

针对车辆协同驾驶领域中的跟随过程,建立了安全距离控制模型,采用BP神经网络PID控制策略设计了控制器,并通过MATLAB/Simulink软件进行仿真分析,将BP神经网络PID控制与传统PID控制的控制效果进行了对比,最后运用缩微环境下的智能车辆系统试验平台设计了Update算法,完成了跟随试验验证。仿真和试验结果表明,本文设计的智能控制器减小了车间距误差,提高了控制准确性,能满足车辆安全跟随行驶要求。     

自动驾驶车辆侧向路径跟随控制算法仿真

路径跟随是依照规划轨迹信息通过对执行元件的控制实现沿期望轨迹行驶,控制算法对实现路径跟随非常重要。针对自动驾驶车辆的侧向控制技术,文章研究了基于最优预瞄理论的路径跟随控制,建立车辆二自由度模型和预瞄误差模型,设计模型预测控制（MPC）侧向跟随控制器以提高跟随精度。利用CarSim-Simulink联合仿真,仿真结果表明,该算法策略能稳定跟踪规划路径。     

安全车距保持技术硬件在环仿真试验系统

自行开发的安全车距保持技术硬件在环仿真试验系统主要由制动执行器、油门执行器、车辆模型和控制算法等组成.该仿真器可用于车辆主动避撞报警系统、自适应巡航控制系统及具有Stop&Go功能的巡航系统的仿真试验,可检验控制器及执行器的性能、设计控制算法等,从而缩短研发周期,节约开发成本.     

Human driving data-based design of a vehicle adaptive cruise control algorithm

This paper presents a vehicle adaptive cruise control algorithm design with human factors considerations. Adaptive cruise control (ACC) systems should be acceptable to drivers. In order to be acceptable to drivers, the ACC systems need to be designed based on the analysis of human driver driving behaviour. Manual driving characteristics are investigated using real-world driving test data. The goal of the control algorithm is to achieve naturalistic behaviour of the controlled vehicle that would feel natural to the human driver in normal driving situations and to achieve safe vehicle behaviour in severe braking situations in which large decelerations are necessary. A non-dimensional warning index and inverse time-to-collision are used to evaluate driving situations. A confusion matrix method based on natural driving data sets was used to tune control parameters in the proposed ACC system. Using a simulation and a validated vehicle simulator, vehicle following characteristics of the controlled vehicle are compared with real-world manual driving radar sensor data. It is shown that the proposed control strategy can provide with natural following performance similar to human manual driving in both high speed driving and low speed stop-and-go situations and can prevent the vehicle-to-vehicle distance from dropping to an unsafe level in a variety of driving conditions.     

Automatic Cruise Control of a Mechatronically Steered Vehicle Convoy

In this paper a convoy of two vehicles is considered where the second one is mechatronically operated. The convoy model used for simulation and controller design is derived by the method of multibody systems. A nonlinear cruise controller based on the concept of flat outputs in connection with exact state linearization is derived. A nonlinear local observer is also implemented. It is shown that such a system responds properly to arbitrary maneuvers performed by the driver of the leading vehicle.     

Model predictive control with constraints for a nonlinear adaptive cruise control vehicle model in transition manoeuvres

A vehicle following control law, based on the model predictive control method, to perform transition manoeuvres (TMs) for a nonlinear adaptive cruise control (ACC) vehicle is presented in this paper. The TM controller ultimately establishes a steady-state following distance behind a preceding vehicle to avoid collision, keeping account of acceleration limits, safe distance, and state constraints. The vehicle dynamics model is for continuous-time domain and captures the real dynamics of the sub-vehicle models for steady-state and transient operations. The ACC vehicle can execute the TM successfully and achieves a steady-state in the presence of complex dynamics within the constraint boundaries.     

Automatic Cruise Control of a Mechatronically Steered Vehicle Convoy

In this paper a convoy of two vehicles is considered where the second one is mechatronically operated. The convoy model used for simulation and controller design is derived by the method of multibody systems. A nonlinear cruise controller based on the concept of flat outputs in connection with exact state linearization is derived. A nonlinear local observer is also implemented. It is shown that such a system responds properly to arbitrary maneuvers performed by the driver of the leading vehicle.     

基于预测恒定车头时距策略的自适应巡航控制研究

为了进一步提高车辆跟车过程中的跟踪性、安全性、舒适性和燃油经济性，针对已有间距策略表现过于保守或反应过于激烈等不足之处，提出了一种预测恒定车头时距策略。该策略考虑了相对加速度，建立了一种预测型期望车间距模型，进而应用于模型预测控制的多目标自适应巡航控制系统中，能进一步提高模型预测控制对多个控制目标的综合协调能力。搭建上层控制器、下层PID控制器、油门制动切换、逆纵向动力学模型。在多工况下仿真，通过建立性能评判指标对多目标进行量化分析。结果表明，所提出的间距策略在保证安全性的前提下，提升了自适应巡航控制系统的综合性能。在不同驾驶风格的车头时距下，跟踪性、舒适性和燃油经济性均有良好表现。     

Connected variable speed limits control and car-following control with vehicle-infrastructure communication to resolve stop-and-go waves

The vision of intelligent vehicles traveling in road networks has prompted numerous concepts to control future traffic flow, one of which is the in-vehicle actuation of traffic control commands. The key of this concept is using intelligent vehicles as actuators for traffic control systems. Under this concept, we design and test a control system that connects a traffic controller with in-vehicle controllers via vehicle-to-infrastructure communication. The link-level traffic controller regulates traffic speeds through variable speed limits (VSL) gantries to resolve stop-and-go waves, while intelligent vehicles control accelerations through vehicle propulsion and brake systems to optimize their local situations. It is assumed that each intelligent vehicle receives VSL commands from the traffic controller and uses them as variable parameters for the local vehicle controller. Feasibility and effectiveness of the connected control paradigm are tested with simulation on a two-lane freeway stretch with intelligent vehicles randomly distributed among human-driven vehicles. Simulation shows that the connected VSL and vehicle control system improves traffic efficiency and sustainability; that is, total time spent in the network and average fuel consumption rate are reduced compared to (uncontrolled and controlled) scenarios with 100% human drivers and to uncontrolled scenarios with the same intelligent vehicle penetration rates.     

四轮独立驱动电动车自适应巡航滑模控制

为实现四轮独立驱动电动汽车的自适应巡航功能,采用基于趋近律的滑模控制理论设计了自适应巡航控制系统.上位控制器以实际车距与期望车距的偏差作为输入,采用滑模控制律获得主车期望加速度,然后将期望加速度作为下位控制器的输入,计算出电机期望转矩,用于实现自适应巡航控制.在CarSim中建立电动汽车整车模型,并与Simulink进...     

刹车状况下桥上随机车流动态演化及车-桥耦合振动分析

为实现刹车时桥上多状态车流并行动态演化的高真实度模拟和时变汽车荷载与桥梁运动状态的时时耦合,首先从宏观和微观上丰富随机车流模拟方法,宏观上沿用交通荷载调查数据中的车辆顺序、车辆基本特性等不变量,以车辆间距为服从正态分布的限幅随机变量,形成深度融合交通荷载调查数据和交通流理论的随机车流高真实度仿真方法;微观上对车辆间距随机变量确定的关键状态-阻塞状态,引入加权速度,实现阻塞密度时车流的走走停停动态描述,采用考虑驾驶人状态的概率分布方法确定车辆时距;实现多密度随机车流的高真实度仿真。其次细化刹车过程模拟,建立车流差异化刹车模型：采用顺次对比方法,筛选桥长范围最不利刹车车流;引入停车视距,考虑驾驶人反应,区分头车和跟驰车辆,精细模拟车辆刹车动态过程和刹车车流演化过程,差异化确定各车辆刹车参数;实现桥上多状态车流并行动态演化模拟。第三建立刹车力学模型,并融入至已有正常车流的车-桥耦合系统,构建可考虑刹车状态的分析系统。最后确定桥梁典型响应和分析指标,以一座大跨斜拉桥为例,对多刹车工况下的桥梁响应进行分析。结果表明：桥上刹车状况一般会产生超过正常行驶状况下的桥梁响应,最不利单车道刹车状况下的塔根弯矩甚至达到跑车工况的2.7倍,简单采用规范冲击系数方法很难实现刹车响应的包络;刹车过程中的桥梁响应最值不仅与采取刹车的车辆数目和桥上车辆保有量有关,还受刹车作用与桥梁原响应趋势的顺逆程度控制;桥梁及桥上刹停车辆的总质量和桥上正常行驶的车辆决定桥梁响应时程曲线趋势振幅;典型桥梁响应的总体趋势,与车流密度和刹车车道数相关性较小,不同时段车流会对梁端顺桥向位移和塔根弯矩产生影响。     

Real-time weighted multi-objective model predictive controller for adaptive cruise control systems

In this paper, a novel spacing control law is developed for vehicles with adaptive cruise control (ACC) systems to perform spacing control mode. Rather than establishing a steady-state following distance behind a newly encountered vehicle to avoid collision, the proposed spacing control law based on model predictive control (MPC) further considers fuel economy and ride comfort. Firstly, a hierarchical control architecture is utilized in which a lower controller compensates for nonlinear longitudinal vehicle dynamics and enables to track the desired acceleration. The upper controller based on the proposed spacing control law is designed to compute the desired acceleration to maintain the control objectives. Moreover, the control objectives are then formulated into the model predictive control problem using acceleration and jerk limits as constrains. Furthermore, due to the complex driving conditions during in the transitional state, the traditional model predictive control algorithm with constant weight matrix cannot meet the requirement of improvement in the fuel economy and ride comfort. Therefore, a real-time weight tuning strategy is proposed to solve time-varying multi-objective control problems, where the weight of each objective can be adjusted with respect to different operating conditions. In addition, simulation results demonstrate that the ACC system with the proposed real-time weighted MPC (RW-MPC) can provide better performance than that using constant weight MPC (CW-MPC) in terms of fuel economy and ride comfort.     

基于ADVISOR的电动汽车传动系统参数设计与性能仿真

对电动汽车电动机、传动系的传动比和电池组容量等参数设计的原则和方法进行了研究,以某种型号电动汽车为研究对象,对其动力传动系的参数进行合理的选择和设计.建立了整车动力传动系统的仿真模型,应用电动汽车仿真软件ADVISOR对整车动力性进行了仿真计算.仿真结果表明,以铅酸电池为能源的电动汽车的加速性、爬坡能力、最大车速、续驶...