宝马主动转向技术概述

回顾了车辆转向系统的发展历程。指出,相比于线控转向,主动转向技术是今后发展的主要趋势。详细介绍了主动转向系统的结构和组成,以及核心部件双行星齿轮机构的工作原理及工作模式。叙述了该系统变传动比、稳定车辆等功能的实现原理,并指出通过与其他动力学控制系统一起实现底盘一体化集成控制将是主动转向技术未来的发展方向。     

宝马车Integral主动转向系统

宝马公司在其新7系（F01、F02）轿车中装备了Integral主动转向系统,该转向系统的转向角叠加减少了驾驶人的转向工作量,并将“线控转向”系统与真实转向反馈信息结合在一起。它还通过独立于驾驶人的转向干预对行驶动态进行稳定干预。为增强动态行驶方面的优势,主动转向系统增加了后轮主动转向功能,两者构成一个完整的主动转向系统。     

全轮独立电驱动车辆电动转向系统的研究

针对电动转向系统提出了基于电机的主动转向和助力转向的软硬件解决方案。在理论分析的基础上设计了主动转向和电动助力转向控制算法和电机驱动电路,并对实验车进行相应改造,进行实车试验。试验结果表明,所设计的电动转向系统能够实现主动转向和助力转向的功能,所设计的主动转向控制算法能够准确跟踪控制目标,所设计的电动助力转向控制算法能够为驾驶员提供感觉良好的转向助力。     

转向操纵稳定系统综合机能剖析及主动控制原理（十四）

传统的定转向传动比机构显然无法满足上述要求，但宝马的主动转向系统通过叠加转向机构完全能够实现。该系统传动比在10～20之间，低速情况下，通过双行星齿轮机构伺服电机的调整角和转向盘转角同向输入，使得系统的传动比较小，实际上是增大了驾驶员的转向角输入，     

宝马轿车主动转向系统结构与故障检修

新款宝马5系车型配备了一种先进的电控转向系统,称为主动转向系统（AFS,Active Front Steering）。该系统不仅能够在转向时为驾驶员提供助力,而且能够以主动方式在转向系统中累加一个附加转向角,从而优化转向,性能。     

宝马E60主动转向系统结构与检修

在E60(新5系)上使用了传统常规齿条齿轮液压助力转向系统,此外还可以使用两个选择的装备:电子转向助力系统和主动转向系统。本篇所讲述的就是这套选装主动转向系统,主动转向系统     

汽车助力转向技术及其控制策略的研究

汽车转向系统发展至今,已经历了机械转向、液压助力转向、电控液压转向、电动助力转向、主动转向、后轮随动转向、线控转向和操纵手柄式转向等形式。本文对各种助力转向系统技术及控制策略进行研究,为转向系统的进一步研究提供理论基础。     

主动转向系统在客车中的应用

介绍汽车转向系统的分类,以及主动转向系统的组成、原理、应用等相关情况。     

主动转向系统及在客车上的应用

阐述了汽车转向系统的分类、主动转向系统的组成、原理、应用等相关情况。     

后桥主动转向在多轴车辆中的应用

本文介绍了后桥主动转向的系统组成和工作原理,以及在8X8重型高机动车辆上的应用情况,对整车性能的提升.经过整车计算,该系统符合全轮转向技术指标,达到车辆使用要求.     

Study on the performance of active front steering system

The performance of a steering system equipped with active front steering (AFS) device is investigated with the consideration of AFS intervention and a proposed dynamic model. Firstly, the kinematics and dynamics of AFS are illustrated based on the mechanism of AFS with planetary gear set and a detailed dynamic model. Furthermore, a basic control on the voltage of DC motor at AFS actuator is proposed. It is realized by a proportional controller that the input is the difference of desired steering ratio and a conventional gear ratio. Finally, two numerical simulations are carried out. One is on-center handling test to demonstrate the basic characteristics of AFS. The other simulation is to demonstrate the effects of vehicle speed, frequency of steering input and AFS intervention on steering system performance. It is shown that the proposed AFS dynamic model is capable to simulate dynamic performance of AFS. The effect of AFS intervention on turning efforts at hand steering wheel is inevitable and the turning comfort is deteriorated to some extent.     

Research on interactive steering control strategy between driver and AFS in different game equilibrium strategies and information patterns

In the past decade, several publications have shown that it is advisable to design an advanced driver assistance system using a shared control structure. This paper is concerned with the modelling and verification of an interactive steering control strategy between a driver and an active front steering (AFS) controller to investigate the complex interactions between human driver and an AFS system. Using game theory as a general framework, a more comprehensive mathematical model system of interactive steering control potentially applicable to explore human drivers’ behaviours in shared control of intelligent vehicles is presented and discussed in this paper. The effects of different information patterns, namely the open-loop pattern and the closed-loop feedback pattern on modelling shared steering control between driver and AFS have been investigated. Simulation and hardware-in-loop implementation results prove the validity of steering interactive modelling in different game information patterns. Specifically, the results show that, in the Nash equilibrium strategy situation, the driver and the AFS controller may become more rational and reasonable in the process of completing the same dynamic task in the closed-loop feedback information patterns compared to the open-loop ones; and the differences between feedback Nash and feedback Stackelberg may depend on the step size of discretisation.     

Integrated control of ground vehicles dynamics via advanced terminal sliding mode control

An integrated vehicle dynamics control (IVDC) algorithm, developed for improving vehicle handling and stability under critical lateral motions, is discussed in this paper. The IVDC system utilises integral and nonsingular fast terminal sliding mode (NFTSM) control strategies and coordinates active front steering (AFS) and direct yaw moment control (DYC) systems. When the vehicle is in the normal driving situation, the AFS system provides handling enhancement. If the vehicle reaches its handling limit, both AFS and DYC are then integrated to ensure the vehicle stability. The major contribution of this paper is in improving the transient response of the vehicle yaw rate and sideslip angle tracking controllers by implementing advanced types of sliding mode strategies, namely integral terminal sliding mode and NFTSM, in the IVDC system. Simulation results demonstrate that the developed control algorithm for the IVDC system not only has strong robustness against uncertainties but also improves the transient response of the control system.     

基于车辆状态识别的AFS与ESP协调控制研究

给出了基于滑模变结构的AFS控制策略和直接横摆力矩加变滑移率联合控制的ESP控制策略。在分析两者控制性能的基础上提出了协调控制的一般原则。阐述了车辆状态识别算法并给出了具体的协调控制策略,最后通过3个典型工况的仿真计算验证了该协调控制策略的有效性。     

汽车液压动力转向器测试系统

一种汽车液压动力转向器性能测试试验台,应用先进的计算机测控原理与信息技术,并采用微机控制液压系 统和伺服电机系统来模拟转向器在现场的工作状况,实现了驱动与加载方式的自动化。该系统性能稳定、操作简单、 测量速度快、测试精度高。     

主动前轮转向控制技术研究现状与展望

主动前轮转向系统提供的独立于驾驶员的转向干预可以提高车辆的操纵稳定性.文中介绍了横摆角速度反馈和横摆角速度与侧偏角联合反馈的稳定性控制算法;阐述了主动前轮转向系统分别与几种动力学控制系统实行集成控制的方法.最后在结论中指出底盘一体化控制将是主动转向技术未来的发展方向.     

Chassis integrated control for active suspension,active front steering and direct yaw moment systems using hierarchical strategy

This paper proposes a novel integrated controller with three-layer hierarchical structure to coordinate the interactions among active suspension system (ASS), active front steering (AFS) and direct yaw moment control (DYC). First of all, a 14-degree-of-freedom nonlinear vehicle dynamic model is constructed. Then, an upper layer is designed to calculate the total corrected moment for ASS and intermediate layer based on linear moment distribution. By considering the working regions of the AFS and DYC, the intermediate layer is functionalised to determine the trigger signal for the lower layer with corresponding weights. The lower layer is utilised to separately trace the desired value of each local controller and achieve the local control objectives of each subsystem. Simulation results show that the proposed three-layer hierarchical structure is effective in handling the working region of the AFS and DYC, while the quasi-experimental result shows that the proposed integrated controller is able to improve the lateral and vertical dynamics of the vehicle effectively as compared with a conventional electronic stability controller.     

主动前轮转向客车的操纵稳定性仿真分析

建立某大型客车的含侧向、横摆及侧倾三自由度动力学模型,通过方向盘角阶跃转向仿真结果和试验数据的比较,验证了仿真分析的准确性。采用横摆角速度跟踪主动前轮转向控制策略,结合比例积分控制方法,在考虑作动器动态特性和前轮转角饱和特性的基础上,对主动前轮转向控制前后的车辆进行直线行驶下的侧向风扰动和湿滑路面急转弯情况下的仿真对比分析。结果表明,主动前轮转向控制后的车辆其操纵稳定性和行车安全性都有较大的提高。     

Development of the Lane Keeping Control System Using State-Varying Surface for Vulnerable Road Users

This paper proposes a new Lane Keeping Assist (LKA) system based on the integrated control strategy with AFS and BTV. To be specific, the steering controller calculates the gear ratio of AFS to align with the target lane whereas the braking controller determines differential brake pressure using Sliding Mode Control (SMC) theory according to the state-varying sliding surface with Fuzzy model. In recent years, auto industries have produced the lane keeping applications to prevent lane departure caused by drivers’ distractions or drowsiness. To also prevent wrist injury in drivers while steering, current LKA systems limit the output values of steering-wheel assist torque. This limiting mechanism, however, can cause a problem that cannot follow a road curvature when an older driver overexerts an inappropriate control effort. A new LKA system of the AFS and BTV integrated controller has since been drafted to solve this problem, and validated its performance in regards to the test conditions given with various driver models.