Speed planning and energymanagement strategy of hybrid electric vehicles in a car-following scenario

The development of intelligent connected technology has brought opportunities and challenges to the design of energy management strategies for hybrid electric vehicles. First, to achieve car-following in a connected environment while reducing vehicle fuel consumption, a power split hybrid electric vehicle was used as the research object, and a mathematical model including engine, motor, generator, battery and vehicle longitudinal dynamics is established. Second, with the goal of vehicle energy saving, a layered optimization framework for hybrid electric vehicles in a networked environment is proposed. The speed planning problem is established in the upper-level controller, and the optimized speed of the vehicle is obtained and input to the lower-level controller. Furthermore, after the lower-level controller reaches the optimized speed, it distributes the torque among the energy sources of the hybrid electric vehicle based on the equivalent consumption minimum strategy. The simulation results show that the proposed layered control framework can achieve good car-following performance and obtain good fuel economy.     

LPV modeling and synthesis for DC propulsion of electric scooters

For electric scooters, this work develops linear parameter‐varying systems (LPV) control synthesis to fulfill the trade‐off between energy consumption per distance and propulsion capability in transience. The synthesized regulator functions as the transmission in the transient state, which is analogous to gear transmission in the steady state. Simulations and experiments are provided to verify the proposed synthesis, wherein a per‐distance strategy is shown to have better performance in terms of energy and motion than a per‐time strategy. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

Centralized and decentralized distributed control of longitudinal vehicular platoons with non‐uniform communication topology

In this paper, the distributed control of a longitudinal platoon of vehicles with non‐uniform communication topology is studied. In the case of non‐uniform communication topology, some eigenvalues of the network's matrix may be complex which complicates the stability analysis of the platoon. Most previous studies on vehicular platooning focus mainly on uniform topologies such as uni‐directional, bi‐directional, and multi predecessors following. Since all eigenvalues of these topologies are real, the stability analysis can be performed in a straightforward manner. A third‐order linear differential model is employed to describe the upper‐level dynamics of each vehicle. The 3 N‐order closed‐loop dynamics of the platoon are decoupled to individual third‐order dynamics by presenting a new approach. Two new centralized and decentralized control protocols are introduced to perform the stability analysis of the closed‐loop dynamics. A constant time headway strategy is employed to adjust the inter‐vehicle spacing. Simulation results with different scenarios are presented to illustrate the effectiveness of the proposed approaches.     

Integrated guidance and control of elastic flight vehicle based on robust MPC

Integrated guidance and control of an elastic flight vehicle based on constrained robust model predictive control is proposed. The design is based on a partial state feedback control law that minimizes a cost function within the framework of linear matrix inequalities. It is shown that the solution of the defined optimization problem stabilizes the nonlinear plant. Nonlinear kinematics and dynamics are taken into account, and internal stability of the closed‐loop nonlinear system is guaranteed. The performance and effectiveness of the proposed integrated guidance and control against non‐maneuvering and weaving targets are evaluated using computer simulations. Copyright © 2014 John Wiley & Sons, Ltd.     

并联混合动力汽车能量管理系统的仿真研究

对于混合动力汽车而言,节能减排是促使其发展的主要原因,而能量管理策略是节能减排的关键技术,因此针对并联混合动力汽车的能量管理策略展开研究;首先运用ADVISOR电动汽车仿真软件,选用某款并联混合动力车型,并使用标准ECE_ECDU和UDDS循环工况来评估整车燃油经济性和污染物排放效果;然后,采用门限参数优化的方法对控制策略进行优化;最后对比优化前后不同循环工况仿真结果中汽车的燃油经济性和排放性能的变化,并分析了优化后的策略对汽车性能的影响;研究表明,所提出的优化方法使汽车在ECE_ECDU和UDDS循环工况中的每百公里油耗分别降低了8.45%和10%,有害气体HC、CO和NOX含量分别减少了5.88%和5.8%、12.24%和11.54%、8.55%和7.51%,进一步验证了优化策略的有效性。     

信息融合架构下的新型再生制动控制策略

再生制动能够实现能量的回收利用,是电动汽车重要的工作模式之一.现有的制动力分配方案对蓄电池和电机的限制因素考虑不够充分,能量回收效率和制动效能较低.对此,提出一种基于信息融合架构下的新型再生制动控制策略.在蓄电池和电机限制因素的基础上,综合考虑增加电动车的续驶里程和制动时的舒适性、安全性等因素,对于电动汽车的不同行驶工况具有自适应性,能够实现能量高效回收;对车辆行驶速度和制动强度进行特征提取和制动模式分类,从而根据特征匹配结果切换制动模式.最后,通过搭建Matlab/Simulink整车动力学仿真模型,验证所提出控制策略的有效性和先进性.     

考虑铁损的电动汽车用感应电机矢量控制及其能量优化策略

电动汽车用感应电机励磁电感一般较小,高速时铁损大,采用经典矢量控制策略存在轻载低效和由忽略铁损引起的控制不精确等问题.首先根据同步旋转坐标系下考虑铁损的感应电机动态数学模型,分析了铁损对按转子磁场定向矢量控制的影响,给出了动态和稳态两种补偿方案.然后从调节磁通水平的角度,提出了一种基于损耗模型的感应电机能量优化控制策略,并讨论了铁损等效电阻变化对优化控制的影响.仿真和实验结果表明,给出的补偿控制策略克服了经典矢量控制磁场定向及转矩控制不准确的缺陷;提出的的能量优化控制策略不但节能效果明显,而且具有寻优速度快、转矩和转速波动小等优点,为高性能要求的电动汽车电驱动系统高效运行提供了有效途径.     

混合动力电动汽车的跟车控制与能量管理

混合动力电动汽车(Hybrid electric vehicles,HEVs)的能量管理问题至关重要,而混合动力电动汽车的跟车控制不仅涉及跟车效果与安全性,也影响着能量的高效利用.将HEVs的跟车控制与能量管理相结合,提出一种基于安全距离的HEVs车辆跟踪与能量管理控制方法.首先,考虑坡度、载荷变动建立了HEVs车辆跟...     

Sliding‐Mode Velocity Control of a Two‐Wheeled Self‐Balancing Vehicle

Underactuated vehicles are those in which the number of control inputs is less than the degrees of freedom to be controlled. Using actuated wheels, velocity control of the two‐wheeled self‐balancing vehicle drives the vehicle at a desired speed and balances the body of the vehicle. First, we investigate the effects of friction on the wheel and derive the hybrid model of rolling and slipping. Second, we propose a nonlinear sliding mode velocity control scheme for the pure rolling model of the two‐wheeled vehicle. We present the design of the corresponding sliding surfaces and internal dynamics of the two‐wheeled vehicle. Our stability analysis reveals that the proposed sliding mode method can guarantee the asymptotic stability of the error dynamics for velocity control of the underactuated vehicle. Compared to linear optimal control, our numerical simulations demonstrate that the proposed sliding mode schemes can effectively control the velocity under the circumstances of parametric variations, emergency braking, and rapid acceleration in slippery road conditions. The proposed velocity control and the simulation improve our understanding on designing velocity control of the two‐wheeled self‐balancing vehicle.     

智能交通系统车道保持纵横向耦合控制

考虑车辆纵横向运动之间的相互影响,采用位置预瞄和固定车辆间距跟随策略,对基于一列车队的自动化公路系统车道保持纵横向耦合控制进行了研究.利用车载前后双位置传感器检测车辆位置偏差,基于车辆纵横向动力学耦合模型,推导了基于预瞄的车道保持控制系统数学模型;采用非奇异的终端滑模控制技术,设计了车道保持纵横向耦合控制规律.通过构造李雅普诺夫函数,结合相平面方法,分析了控制系统的有限时间收敛性.采用6车辆编队,通过计算机仿真,对文中设计的控制规律进行了验证.仿真结果显示,车队中每个被控车辆在纵向上跟随期望状态的同时能够实现对期望车道轨迹的理想跟踪,跟踪误差精度不超过0.05 m.     

Estimation of road frictional force and wheel slip for effective antilock braking system (ABS) control

The introduction of electric braking via brake‐by‐wire systems in electric vehicles) has reduced the high transportation delays usually involved in conventional friction braking systems. This has facilitated the design of more efficient and advanced control schemes for antilock braking systems (ABSs). However, accurate estimation of the tire‐road friction coefficient, which cannot be measured directly, is required. This paper presents a review of existing estimation methods, focusing on sliding‐mode techniques, followed by the development of a novel friction estimation technique, which is used to design an efficient ABS control system. This is a novel slip‐based estimation method, which accommodates the coupling between the vehicle dynamics, wheel dynamics, and suspension dynamics in a cascaded structure. A higher‐order sliding‐mode observer–based scheme is designed, considering the nonlinear relationship between friction and slip. A first‐order sliding‐mode observer is also designed based on a purely linear relationship. A key feature of the proposed estimation schemes is the inclusion of road slope and the effective radius of the tire as an estimated state. These parameters impact significantly on the accuracy of slip and friction estimation. The performance of the proposed estimation schemes are validated and benchmarked against a Kalman filter (KF) by a series of simulation tests. It is demonstrated that the sliding‐mode observer paradigm is an important tool in developing the next generation ABS systems for electric vehicles.     

基于混合蚁群算法的冷链电动汽车车辆路径问题

用电动汽车进行冷链物流配送符合绿色物流的发展趋势。针对电动汽车冷链配送需消耗更多能源以维持低温环境,而电动汽车续驶里程短、充电时间长,致使运营成本高的现象,思考了电动汽车配送中的冷链车辆路径问题（REVRP）。考虑电动汽车能耗特点和社会充电站的充电需求,构建了以总配送成本最小为优化目标的线性规划模型,而目标函数由固定成本和可变成本构成,其中可变成本包含运输成本和制冷成本。模型考虑容量约束和电量约束,并设计混合蚁群（HACO）算法对其进行求解,其中重点设计了适合社会充电站的转移规则以及4种局部优化算子。在改进Solomon基准算例的基础上,形成了小规模和大规模两个算例集,并通过实验比较了蚁群（ACO）算法和局部优化算子的性能。实验结果表明,在小规模算例集中,传统ACO算法与CPLEX求解器均能找到精确解,而ACO算法在运算时间方面可节省99.6%;而在大规模算例集中,与ACO算法相比,结合4种局部优化算子的HACO算法的平均优化效率提升了4.45%。所提算法能够在有限时间内得出电动汽车REVRP的可行解。     

基于改进粒子群算法的电动汽车停车场V2G策略研究

为解决电动汽车大规模并网带来的一系列问题,国内外逐步在城市商业停车场内提供电动汽车充电服务。在此背景下,提出一种基于电动汽车并网技术的电动汽车充放电停车场模型。该模型响应实时电价,对电动汽车的充电并网行为进行动态调度,继而与电网进行能量交互。在求解电动汽车最优调度策略时采用粒子群优化算法,从可行性编码、自适应搜索半径、边界变异修正等方面进行改进,以提高算法的效率及收敛精度。仿真实验采用美国PJM公司的实时电价数据及主流电动汽车的型号参数,对比分析了3种不同情景下电动汽车停车场的运营过程及结果,验证了所提模型的合理性以及改进算法的有效性。     

A robust integrated controller/diagnosis aircraft application

In this paper, an application of the robust integrated control/diagnosis approach using ??_∞‐optimization techniques to the nonlinear longitudinal dynamics of a Boeing 747‐100/200 aircraft is presented. The integrated approach allows to address directly the trade‐off between the conflicting controller and fault diagnosis objectives. The integrated design formulation (interconnection and weight selection) is defined using five LTI plants obtained through out the Up‐and‐Away flight envelope. Linear and nonlinear closed‐loop time simulations are carried out under a realistic turbulence and noise environment. A comparison drawn with the non‐integrated design of a controller and a diagnosis filter with the same objectives shows that the integrated case results in similar diagnosis characteristics but improved fault tolerant performance and ease of design. Copyright © 2005 John Wiley & Sons, Ltd.     

基于滚动优化和能量回收的V2I电动汽车决策

通过对标准新欧洲汽车法规循环(NEDC)工况的分析,提取出NEDC工况中的实时交通信息,分析不同驾驶状态对于车辆能耗的影响,提出一种新的基于实时交通信息的适用于V2I车辆的测试工况;结合电动汽车能量回收的优点,考虑电池-电机-制动特性约束,设计多源信息融合框架下的制动力分配策略;结合模型预测控制(MPC)的滚动优化思想提出MPC软约束框架下的电动汽车V2I最优控制策略;在AMESim & Simulink联合仿真平台上进行高精度纯电动车整车建模和MPC最优控制器的设计;对优化后车辆和未优化的车辆进行仿真对比验证,结果表明:结合道路交通信息进行最优决策的V2I纯电动车辆可有效降低车辆运行中的启停频率,减少整车能耗、车辆加速度和冲击度幅度,并显著提高整车经济性和舒适性.     

Tire–road friction coefficient and tire cornering stiffness estimation based on longitudinal tire force difference generation

A sequential tire cornering stiffness coefficient and tire–road friction coefficient (TRFC) estimation method is proposed for some advanced vehicle architectures, such as the four-wheel independently-actuated (FWIA) electric vehicles, where longitudinal tire force difference between the left and right sides of the vehicle can be easily generated. Such a tire force difference can affect the vehicle yaw motion, and can be utilized to estimate the tire cornering stiffness coefficient and TRFC. The proposed tire cornering stiffness coefficient and TRFC identification method has the potential of estimating these parameters without affecting the vehicle desired motion control and trajectory tracking objectives. Simulation and experimental results with a FWIA electric vehicle show the effectiveness of the proposed estimation method.     

低速电动汽车的性能研究

电动汽车是解决能源危机和环境污染的有效方法,但就目前情况来看,电动汽车大规模使用仍需时日。尽管如此,低速电动汽车目前已在中国低端电动汽车市场取得了成功。文章探讨了低速电动汽车的行驶特性、动态性能、电池性能和能量效率。通过底盘测功机实验测试与室外道路实验,分析了低速电动汽车的负载特性和过载特性,研究不同电池对低速电动车性价比的影响。虽然目前锂离子电池比铅酸电池成本更高,但实际应用中,锂离子电池效率更高、全寿命行驶距离更长。直流驱动电机有优秀的过载能力,但电机系统的低效率限制了低速电动汽车的整车能量效率。因此,开发低成本、高效率的电池及电机驱动系统是提高低速电动车性价比的有效途径。     

Real-time optimization of energy consumption under adaptive cruise control for connected HEVs

This paper presents a real-time energy optimization algorithm for a hybrid electric vehicle (HEV) that operates with adaptive cruise control (ACC). Real-time energy optimization is an essential issue such that the HEV powertrain system is as efficient as possible. With connected vehicle technique, ACC system shows considerable potential of high energy efficiency. Combining a classical ACC algorithm, a two-level cooperative control scheme is constructed to realize real-time power distribution for the host HEV that operates in a vehicle platoon. The proposed control strategy actually provides a solution for an optimal control problem with multi objectives in terms of string stable of vehicle platoon and energy consumption minimization of the individual following vehicle. The string stability and the real-time optimization performance of the cooperative control system are confirmed by simulations with respect to several operating scenarios.     

基于GT-SUITE与Simulink的车辆驱动冷却系统联合仿真分析

为降低纯电动汽车的能耗、提高电池的续航里程,联合GT SUITE与Simulink搭建整车驱动冷却系统和动力系统模型,对某纯电动汽车的热平衡性能进行分析。在所考察工况及电子水泵最大转速条件下,冷却回路最高水温远低于系统设计的温度限值,存在优化空间。通过过程优化,寻找合适的电子水泵转速,在满足系统设计要求的同时,最大限度地减少能耗,为热管理系统控制策略的制定提供参考。     

Integrated vehicle control through the coordination of longitudinal/lateral and vertical dynamics controllers: Flatness and LPV/‐based design

This paper deals with global chassis control of automotive vehicles. It focuses on the coordination of suspension and steering/braking vehicle controllers based on the interaction between the vertical and lateral behaviors of the vehicle. It is shown that the lateral acceleration and resulting roll motion of the car generate load transfers that considerably affect vehicle stability. A control law is designed in hierarchical way to improve the overall dynamics of the vehicle and cope with coupled driving maneuvers like obstacle avoidance using steering control and stop‐and‐go control using braking or driving wheel torque. This global control strategy includes two types of controllers. The first one is the longitudinal/lateral nonlinear flatness controller. Based on an appropriate choice of flat outputs, the flatness proof of a 3 DOF two‐wheel nonlinear vehicle model is established. Then, the combined longitudinal and lateral vehicle control is designed using algebraic estimation techniques to provide an accurate estimation of the derivatives and filtering of the reference flat outputs. The second part of the proposed strategy consists of a linear parameter‐varying/ suspension controller. This controller uses lateral acceleration as a varying parameter to account for load transfers that directly affect the suspension system. The coordination between the vehicle vertical and lateral dynamics is highlighted in this study, and the linear parameter‐varying/ framework ensures a specific collaborative coordination between the suspension and the steering/braking controllers, to achieve the desired performance. Simulations on a complex full vehicle model have been validated using experimental data obtained on‐board a real Renault Mégane Coupé. Copyright © 2017 John Wiley & Sons, Ltd.