先进的底盘控制系统的发展趋势

电子控制的底盘系统,通过优化轮胎与路面的相互作用(纵向、侧向和垂直方向),大大地提高了车辆的安全性。防抱死制动系统(ABS)、四轮驱动(4WD)和牵引控制系统(TCS)是优化纵向动态稳定性的三种常用的技术。传统的四轮驱动系统采用一个带粘度耦合器的分动箱。当前后轮转数不等时,该耦合器就接合。但是,据摩托罗拉的产品开发人员介绍,新的电子控制系统则更加有效,因为这种四轮驱动系统在运作前不需要有显著的打滑发生,而传动系统的扭转以及牵引和制动能力都得到更好地优化。     

2019年奥迪A7L变速器和四驱偶尔报警

车型:2019年新款奥迪A7L。故障现象:变速器和四驱偶尔报警。故障诊断:(1)首先根据销售顾问的描述试车,当加油后踩制动踏板减速到33km/h左右时,变速器红灯报赘(变速器故障,注意安全),然后熄灭,接着四轮驱动系统报普(四轮驱动系统故障,可以继续行驶),一直亮起,伴随有轻微的耸车,阿能是四轮驱动控制单元工作的原因,当停车后重新开闭钥匙门,仪表报警消失。     

问与答

问:我有一辆1990款的通用四轮驱动K2500型卡车,制动时后轮出现制动抱死现象,并且在稍微用力刹车时。制动效果却不明显。拆检发现。后轮制动分泵泄漏。且前轮摩擦块已经磨损得差不多了。更换后试车,制动抱死现象依然如故。请问这是什么故障?     

奥迪Q7全时四轮驱动系统结构与组成(上)

在奥迪Q7车身上实现了奥迪拥有的全部创新汽车技术:quattro全时四轮驱动技术、动态行驶性能控制(DRC)、全铝车身框架结构(ASF)、多媒体交互系统(MMI)、multitronic无级／手动一体式／双离合器直接换挡变速器(DSG)、双级制动系统、电子制动力分配(EBD)、电子稳定程序(ESP)、TDI／FSI燃油直喷／双涡轮增压发动机、LED技术、电控机械驻车制动、自适应性空气悬挂、主动转向大灯系统、自适应巡航系统、换道辅助系统等等。本文重点介绍奥迪Q7 quattro全时四轮驱动系统。     

《玩转四驱》 【贰拾壹】冰雪

正第1节速度和制动快速是冰雪驾驶头号敌人根据路面情况,选择合适的车速行驶,是冰雪行驶的基本原则。保持一定速度,不能太快但也不能太慢。四轮驱动车辆具有较强的抓地力,因此它们在冰雪路面上的行驶速度往往比两轮驱动车辆更快,但它的制动系统与两轮驱动车辆是一样,并没有特别之处,所以一定要注意控制车速,尤其是在转弯时,防止车辆     

奥迪100／200型轿车三通道ABS控制过程分析

奥迪（ＡＵＤＩ）系列轿车采用的是防抱死制动系统（ＡＢＳ）主要有三通道四传感器ＡＢＳ和四通道四传感器ＡＢＳ两大类多种型号，虽然各型ＡＢＳ的结构与分布有所不同，但是其控制过程大同小异。本文以奥迪（ＡＵＤＩ）１００／２００四轮驱动型轿车三通道ＡＢＳ为例说明其控制过程。     

全时四驱解析四款全时四驱系统

1980年,Quattro面世,奥迪设计师声称：“早晚有一天,全时四驱会像四轮碟式制动一样流行。”当时很多人都把它看作是一种销售宣传口号,但今天的奥迪用全时四驱武装了它的每一款车型,而各大厂商也在争先恐后的加入全时四驱的行列。为什么四轮驱动会得到大家的重视．四轮驱动的最新技术又是怎样?     

四轮轮毂电机驱动电动汽车无刷电机控制算法的研究

在分析四轮驱动轮毂电机电动汽车不同电机控制算法优缺点的基础上,提出了一种新的多模式电机控制算法.该算法对高速驱动采用矢量控制或六步换相控制;低速驱动和制动采用正弦波电压或矢量控制.针对轮毂电机多模式控制的复杂性,采用了Matlab/Simulink的Stateflow工具箱实现控制模式切换,整车控制算法在Matlab/Simulink环境下实现,并通过全自动代码生成下载到MPC5633M单片机中,保证了电机多模式控制的可靠切换.仿真和试验结果证明了这种算法的可行性,电机噪声降低,整车性能提高.     

四轮驱动电动汽车稳定性控制模型搭建及模型准确性验证

基于CarSim/Simulink平台,搭建四轮驱动电动汽车联合仿真控制模型,在双移线工况下,验证所建立的四轮驱动电动汽车控制仿真模型的准确性,结果显示,所建立的四轮驱动电动汽车整车模型与CarSim里B级车模型性能具有高度一致性,这说明所搭建的四轮驱动电动汽车模型具有较高精确度,同时该模型的搭建也为后续的四轮独立驱动电动汽车稳定性控制奠定研究基础。     

1995款三菱蒙迪欧制动偏摆

一辆三菱蒙迪欧V43吉普车,行驶里程为15 万km(95200英里)。 故障现象:该车配备自动变速器,四轮驱动,无ABS 制动防抱死系统。当车速达40km/h以上时,无论是紧急制动,还是点刹或缓 慢制动,方向均明显偏右。 故障诊断:接到该故障 车后,试车发现制动时方向 严重偏右。因该车无AB     

独立悬架-电动轮模块的双横臂悬架机构设计

四轮驱动电动汽车采用由轮毂电机、转速传感器、制动盘和双横臂悬架机构组成的结构相同的独立悬架-电动轮模块，可大幅度减少零部件种类，降低制造成本。文中按空间机构理论导出了双横臂悬架导向机构运动分析与设计的基本公式，并研制成简明实用的视窗式分析与设计系统。提出了可完全消除附加转向干涉的非转向轮双横臂悬架导向机构。将这些研究成果具体应用于国内第一台四轮驱动燃料电池微型汽车概念平台“春晖一号”和样车“春晖二号”的研制，取得了良好效果。     

Distributed and self-adaptive vehicle speed estimation in the composite braking case for four-wheel drive hybrid electric car

Considering the controllability and observability of the braking torques of the hub motor, Integrated Starter Generator (ISG), and hydraulic brake for four-wheel drive (4WD) hybrid electric cars, a distributed and self-adaptive vehicle speed estimation algorithm for different braking situations has been proposed by fully utilising the Electronic Stability Program (ESP) sensor signals and multiple powersource signals. Firstly, the simulation platform of a 4WD hybrid electric car was established, which integrates an electronic-hydraulic composited braking system model and its control strategy, a nonlinear seven degrees-of-freedom vehicle dynamics model, and the Burckhardt tyre model. Secondly, combining the braking torque signals with the ESP signals, self-adaptive unscented Kalman sub-filter and main-filter adaptable to the observation noise were, respectively, designed. Thirdly, the fusion rules for the sub-filters and master filter were proposed herein, and the estimation results were compared with the simulated value of a real vehicle speed. Finally, based on the hardware in-the-loop platform and by picking up the regenerative motor torque signals and wheel cylinder pressure signals, the proposed speed estimation algorithm was tested under the case of moderate braking on the highly adhesive road, and the case of Antilock Braking System (ABS) action on the slippery road, as well as the case of ABS action on the icy road. Test results show that the presented vehicle speed estimation algorithm has not only a high precision but also a strong adaptability in the composite braking case.     

Force control for path following of a 4WS4WD vehicle by the integration of PSO and SMC

The aim of this paper is to present a novel control method for a four-wheel steer and four-wheel drive (4WS4WD) vehicle. The novelty is in the integration of sliding mode control (SMC) and particle swarm optimization (PSO) that is proposed to solve the control problem caused by the nonlinear, highly coupled and over-actuated characteristics of the four-wheel steer and four-wheel drive (4WS4WD) vehicle. The validity of the control method is evaluated by two criterions, namely path following performance assessed by the vehicle's position errors with respect to the reference path, and motion quality reflected by the smoothness of vehicle's velocities and accelerations. In vehicle modelling, a kinematic model and a dynamic model considering all slip forces are proposed for the controller design. Simulation results are provided to demonstrate the applicability of the proposed methodology and its robustness.     

基于路面抗滑性能的高速公路行车安全分析

对广东省内某大交通流量、交通事故多发的高速公路的路面抗滑性能和交通事故进行收集、整理、分析,采用事故率、雨天事故率、晴天事故率对路面抗滑性能和交通事故进行相关性分析,得到其相关关系,并在此基础上提出基于控制路面事故率来对路面抗滑性能进行针对性的提高或维护。     

Direct tire force generation algorithm based on non-iterative nonlinear inverse tire model

The function of vehicle dynamics control system is adjusting the yaw moment, the longitudinal force and lateral force of a vehicle body through several chassis systems, such as brakes, steering and suspension. Individual systems such as ESC, AFS and 4WD can be used to achieve desired performance by controlling actuator variables. However, integrated chassis control systems that have multiple objectives may not simply achieve the desired performance by controlling the actuators directly. Usually those systems determine the required tire forces in an upper level controller and a lower level controller regulates the tire forces through the actuators. The tire force is controlled in a recursive way based on vehicle state measurement, which may not be sufficient for fast response. For immediate force tracking, we introduce a direct tire force generation method that uses a nonlinear inverse tire model, a pseudo-inverse model of vehicle dynamics and the relationship between longitudinal force and brake pressure.     

Comparisons of vehicle stability controls based on 4WS,Brake, Brake-FAS and IMC techniques

This paper proposes three different kinds of vehicle stability control systems all based on internal model control (IMC) strategy which are 4WS (4 wheel steer: front- and rear-wheel active steer) IMC, Brake-FAS (brake and front-wheel active steer) IMC and Brake IMC, respectively. Inverse system method is introduced to solve the nonlinearity coupled with brake involved vehicle stability control systems. Based on an 11-DOF (degrees of freedom) Matlab/Simulink^® vehicle model testified by CarSim7^®, simulations combined with different driving manoeuvres and road surfaces are performed, and detailed comparisons and analyses are given based on simulation results.     

基于纹理分形特性的沥青路面抗滑性能研究综述

沥青路面纹理形貌是影响道路抗滑性能的重要因素,而路面纹理具有自相似分形特性,因此借助分形特性实现路面纹理量化,对研究路面纹理与抗滑性能之间的联系具有重要意义。从宏观和微观这2个层面总结了沥青混合料纹理和集料纹理的单重、多重分形特性相关研究;分析了分形理论在路面抗滑级配设计和抗滑集料筛选中的应用,总结了基于分形理论的多种抗滑级配设计模型,提出了基于分形理论的集料优选新思路;对比分析了分形理论与参数统计法、力学解析法及有限元模拟法在路面抗滑性能预测中的结合应用。研究结果表明:分形分析为路面纹理描述提供了新思路,但其分析方法仍未突破关键瓶颈,在模型精确性、标准化、系统性方面仍有一定限制;分形理论与抗滑级配设计和抗滑集料筛选的结合应用仍处于探索阶段,需进一步加强设计方法的合理性研究,验证其在实际工程中的适用性;横向对比各类基于纹理分形特性的抗滑预测模型性能,结果表明,有限元模拟预测模型在实际应用中能更准确地还原复杂条件下的胎-路接触状态,更具发展潜力。展望了基于纹理分形特性的沥青路面抗滑性能的未来研究方向,主要包括多尺度的纹理分形特征与抗滑性能的关联规律、实际工程分形参数判别标准,以及基于分形理论的智能抗滑预测体系构建。      

Heavy-duty vehicle modelling and longitudinal control

This paper addresses modelling, longitudinal control design and implementation for heavy-duty vehicles (HDVs). The challenging problems here are: (a) an HDV is mass dominant with low power to mass ratio; (b) They possess large actuator delay and actuator saturation. To reduce model mismatch, it is necessary to obtain a nonlinear model which is as simple as the control design method can handle and as complicated as necessary to capture the intrinsic vehicle dynamics. A second order nonlinear vehicle body dynamical model is adopted, which is feedback linearizable. Beside the vehicle dynamics, other main dynamical components along the power-train and drive-train are also modelled, which include turbocharged diesel engine, torque converter, transmission, transmission retarder, pneumatic brake and tyre. The braking system is the most challenging part for control design, which contains three parts: Jake (engine compression) brake, air brake and transmission retarder. The modelling for each is provided. The use of engine braking effect is new complementary to Jake (compression) brake for longitudinal control, which is united with Jake brake in modelling. The control structure can be divided into upper level and lower level. Upper level control uses sliding mode control to generate the desired torque from the desired vehicle acceleration. Lower level control is divided into two branches: (a) engine control: from positive desired torque to desired fuel rate (engine control) using a static engine mapping which basically captures the intrinsic dynamic performance of the turbo-charged diesel engine; (b) brake control: from desired negative torque to generate Jake brake cylinder number to be activated and ON/OFF time periods, applied pneumatic brake pressure and applied voltage of transmission retarder. Test results are also reported.     

Heavy-duty vehicle modelling and longitudinal control

This paper addresses modelling, longitudinal control design and implementation for heavy-duty vehicles (HDVs). The challenging problems here are: (a) an HDV is mass dominant with low power to mass ratio; (b) They possess large actuator delay and actuator saturation. To reduce model mismatch, it is necessary to obtain a nonlinear model which is as simple as the control design method can handle and as complicated as necessary to capture the intrinsic vehicle dynamics. A second order nonlinear vehicle body dynamical model is adopted, which is feedback linearizable. Beside the vehicle dynamics, other main dynamical components along the power-train and drive-train are also modelled, which include turbocharged diesel engine, torque converter, transmission, transmission retarder, pneumatic brake and tyre. The braking system is the most challenging part for control design, which contains three parts: Jake (engine compression) brake, air brake and transmission retarder. The modelling for each is provided. The use of engine braking effect is new complementary to Jake (compression) brake for longitudinal control, which is united with Jake brake in modelling. The control structure can be divided into upper level and lower level. Upper level control uses sliding mode control to generate the desired torque from the desired vehicle acceleration. Lower level control is divided into two branches: (a) engine control: from positive desired torque to desired fuel rate (engine control) using a static engine mapping which basically captures the intrinsic dynamic performance of the turbo-charged diesel engine; (b) brake control: from desired negative torque to generate Jake brake cylinder number to be activated and ON/OFF time periods, applied pneumatic brake pressure and applied voltage of transmission retarder. Test results are also reported.