基于主动安全的轮问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。     

汽车主动控制悬架系统的发展

主动控制悬架有使汽车乘坐舒适性和操纵安全性得到改善，本简要地介绍了国外汽车主动控制悬架系统的发展及现状；给出了流量控制型和压力控制型两种控制方式的简图；阐述压力控制型主动悬架系统的基本工作原理，以及天棚阻尼器控制、最优控制、预见控制等方法。     

主动悬架系统的连续模糊控制

在主动悬架系统中，动力装置的控制非常重要。为了能在利用较少的状态量作为反馈信号的条件下达比较理想的控制效果，宜采用连续模型控制方法来实现主动悬架动力装置的控制。模拟计算表明， 该方法可使汽车的行驶平顺性和安全性同时得到有效改善。     

基于主动转向技术的汽车防侧翻控制的研究

以汽车2自由度模型作为参考模型，建立了一种汽车防侧翻的控制方法。该方法采用主动转向技术来改变转向轮的转向角度，有效地减少了汽车的侧向加速度，提高了汽车的防侧翻的能力。在8自山度汽车动力学模型的基础上，运用主动转向技术的控制策略进行了汽车的性能仿真分析。与末采用汽车防侧翻控制系统的汽车动力学分析结果相比，汽车的主动安全性得到了增强。     

汽车防抱死制动系统控制方法的研究进展

汽车防抱死制动系统（简称ABS）是改善汽车主动安全性的重要装置，在汽车日益高速化的今天，它的应用日益广泛，ABS控制方法是ABS的核心技术，掌握控制方法的设计和匹配，对于自主开发ABS和进一步开展汽车主动安全性理论和技术研究有着重要的现实意义。ABS广泛采用的是逻辑门限值控制，这对于非线性系统是一种有效的控制方法，本文讨论了几种不同的控制逻辑，通过对制动过程的动态模拟，比较了其防抱性能的优劣。同时，提出了一种以制动器耗散功率最大为目标的ABS控制方法。     

汽车ABS滑模变结构控制的分析与仿真

汽车防抱制动系统(ABS)是改善汽车主动安全性的重要装置.本文介绍了滑模变结构控制方法,针对汽车ABS的特点利用此方法设计了控制器,并在MATLAB/Simulink的环境下进行了仿真,给出了仿真结果和评价.     

基于微分几何的汽车主动悬架模糊PID控制研究

文章以汽车主动悬架为研究对象,结合二自由度非线性汽车主动悬架动力学模型,利用微分几何理论将非线性模型精确线性化后,首先设计PID控制器,为抑制干扰因素影响而引起系统参数或结构改变,提高悬架系统应对复杂工况下的自适应能力,然后设计了利用模糊控制原理对PID参数进行在线整定的自适应模糊PID控制器。仿真结果表明:相比于参数固定的被动悬架系统,采用该控制方法的主动悬架能够轻松应对各种工况,不仅在保证改善汽车乘坐的舒适性的情况下,同时进一步改善了车辆的行驶平顺性和行驶安全性,为汽车主动悬架系统控制策略设计提供实用性参考。     

面向主动安全的汽车底盘集成控制策略

研究主动安全的汽车底盘集成控制策略，可以提高汽车的行驶稳定性、操控性和安全性。主要介绍了汽车底盘的概念及其在汽车安全中的重要性，探讨目前主动安全系统在汽车底盘控制中的应用，并分析了现有控制策略存在的问题和局限性。针对面向主动安全的底盘集成控制策略提出研究方向，包括传感器数据融合、底盘系统的动态调整和主动干预控制等。强调该领域的研究对于提高汽车主动安全性的重要性，并对未来的发展和挑战进行展望。     

四轮转向汽车主动转向控制及仿真

以四轮转向汽车为研究对象,建立车辆四轮转向动力学模型。基于后轮主动转向控制方法,分别搭建四轮转向汽车前后轮转角成比例的主动转向控制模型以及基于车速和横摆角速度反馈的主动转向控制模型。在高速转向工况下,采用MATLAB/Simulink建立四轮转向汽车主动转向控制仿真模型进行对比仿真。仿真结果表明,该控制方法能够较好地减小车辆质心侧偏角及横摆角速度,保证车辆良好的轨迹跟踪能力,有效地改善了车辆的操纵稳定性。     

全挂汽车列车主动转向建模分析

汽车列车在公路交通运输中起着举足轻重的作用,为公路货运量流通提供高性价比的运输方式,贴合当代发展需求。随着汽车列车使用需求日益增长,其不足之处也日益凸显,因而提高汽车列车的运输效率及安全性,保证汽车列车长远发展势在必行。现基于一种双杆式全挂汽车列车提出主动转向控制研究方法,使车辆进行弯道行驶时,在主动转向装置和主动转向控制方法的双重作用下实现挂车对牵引车的转向运动进行主动跟随。文章建立连接装置、电液控制部分以及全挂车模型,仿真结果证明该转向系统具有稳定性。     

线控转向稳态增益与动态反馈校正控制算法

以29自由度汽车动力学模型为基础,提出了保证线控汽车转向增益不变的稳态控制策略,使线控汽车转向特性不随车速和转向盘转角变化;提出了基于状态反馈的动态校正稳定性控制算法。仿真和驾驶模拟器实验表明,基于转向增益不变的稳态控制策略保证了汽车转向特性不变,减轻了驾驶员的负担,适合于更多的驾驶人群;基于状态反馈的动态校正稳定性控制算法有效提高了汽车的稳定性。     

Literature review and fundamental approaches for vehicle and tire state estimation*

ABSTRACT

Most modern day automotive chassis control systems employ a feedback control structure. Therefore, real-time estimates of the vehicle dynamic states and tire-road contact parameters are invaluable for enhancing the performance of vehicle control systems, such as anti-lock brake system (ABS) and electronic stability program (ESP). Today's production vehicles are equipped with onboard sensors (e.g. a 3-axis accelerometer, 3-axis gyroscope, steering wheel angle sensor, and wheel speed sensors), which when used in conjunction with certain model-based or kinematics-based observers can be used to identify relevant tire and vehicle states for optimal control of comfort, stability and handling. Vehicle state estimation is becoming ever more relevant with the increased sophistication of chassis control systems. This paper presents a comprehensive overview of the state-of-the-art in the field of vehicle and tire state estimation. It is expected to serve as a resource for researchers interested in developing vehicle state estimation algorithms for usage in advanced vehicle control and safety systems.     

智能汽车自动紧急转向避撞的跟踪控制方法对比研究

为了提高智能汽车的主动安全性,提出3种不同的自动紧急转向避撞跟踪控制方法。首先建立汽车避撞简化模型,对制动、转向及两者相结合的3种不同避撞方式进行对比分析。其次,为深入研究汽车避撞过程中的实际响应,建立包含转向、制动及悬架3个子系统耦合特性的底盘18自由度统一动力学模型,并进行相关试验验证。随后构建智能汽车自动紧急转向避撞控制框架,对五次多项式参考路径和七次多项式参考路径的横摆角速度和横摆角加速度进行对比分析。接着以线性2自由度转向动力学模型为参考对象,对最优控制四轮转向、最优控制前轮转向、前馈与反馈控制相结合的前轮转向3种不同的跟踪控制系统分别进行设计。最后,以汽车底盘18自由度统一动力学模型为研究对象,对上述3种避撞控制系统进行仿真试验对比分析。研究结果表明：与制动避撞相比而言,转向避撞所需的纵向距离有较大降低,随着车速的增加和路面附着系数的越低,效果越明显;七次多项式参考路径比五次多项式参考路径的避撞过渡过程更为平缓,当实际车速与控制器所用车速不一致时,前者避撞性能表现更优;最优四轮转向控制系统在高、低2种不同附着路面都具有较好的避撞效果,最优前轮转向控制系统次之,而前馈与反馈相结合的前轮转向控制系统在低附着路面上则表现出严重的失稳。     

基于车联网的汽车自动换道方法研究

为弥补现有汽车自动换道时未考虑周围车辆运动状态变化以及舒适性差和通行效率低等方面的不足,同时提出了在车联网条件下的汽车自动换道方法,主要包括动态轨迹的规划、前馈与反馈相结合的PQ跟踪控制策略两部分,开展Carsim和simulink联合仿真以及实车验证结果表明,与传统非动态自动换道方法相比,该方法能有效解决在换道过程中周围车辆车速变化及车辆突然闯入等情况的难题,明显提高了换道过程中的安全性,由数据分析可知在保证车辆舒适性、稳定性的同时,换道时间缩短了20%,有效提高了车辆换道效率。     

Design and hardware-in-loop implementation of collision avoidance algorithms for heavy commercial road vehicles

An important aspect from the perspective of operational safety of heavy road vehicles is the detection and avoidance of collisions, particularly at high speeds. The development of a collision avoidance system is the overall focus of the research presented in this paper. The collision avoidance algorithm was developed using a sliding mode controller (SMC) and compared to one developed using linear full state feedback in terms of performance and controller effort. Important dynamic characteristics such as load transfer during braking, tyre-road interaction, dynamic brake force distribution and pneumatic brake system response were considered. The effect of aerodynamic drag on the controller performance was also studied. The developed control algorithms have been implemented on a Hardware-in-Loop experimental set-up equipped with the vehicle dynamic simulation software, IPG/TruckMaker®. The evaluation has been performed for realistic traffic scenarios with different loading and road conditions. The Hardware-in-Loop experimental results showed that the SMC and full state feedback controller were able to prevent the collision. However, when the discrepancies in the form of parametric variations were included, the SMC provided better results in terms of reduced stopping distance and lower controller effort compared to the full state feedback controller.     

Fidelity of using scaled vehicles for chassis dynamic studies

There are many situations where physical testing of a vehicle or vehicle controller is necessary, yet use of a full-size vehicle is not practical. Some situations include implementation testing of novel actuation strategies, analysing the behaviour of chassis feedback control under system faults, or near-unstable situations such as limit handling under driver-assist feedback control. Historically, many have advocated the use of scale vehicles as surrogates for larger vehicles. This article presents analysis and experimental testing that examines the fidelity of using scaled vehicles for vehicle chassis dynamics and control studies. In support of this effort, this work introduces an experimental system called the Pennsylvania State University Rolling Roadway Simulator (the PURRS). In the PURRS, a custom-built scale-sized vehicle is freely driven on a moving roadway surface. While others have used scale-vehicle rolling roadway simulators in the past, this work is the first to attempt to directly match the planar dynamic performance of the scale-sized vehicle to a specific full-sized vehicle by careful design of the scale vehicle. This article explains details of this effort including vehicle dynamic modelling, detailed measurement of model parameters, conditions for dynamic similitude, validation of the resulting experimental vehicle in the time, frequency, and dimensionless domains. The results of the dynamic comparisons between scale- and full-sized vehicles clearly illustrate operational regimes where agreement is quite good, and other regimes where agreement is quite poor. Both are useful to understand the applicability of scale-vehicle results to full-size vehicle analysis.     

Application of Aerodynamic Actuators to Improve Vehicle Handling

This exploratory study considers applications of active aerodynamic devices for suppressing parasitic motion and for improving the response of vehicles to steering, within the scope of the linear dynamic behaviour. A three DOF linear model is chosen to describe the side slip, yaw and roll motion of a baseline front-wheel steered vehicle. The improvements in performance of the base-line vehicle that are achievable by the application of direct yaw and roll moments are determined when either an open loop control pre-filter or a state feedback control law based on LQR design is applied. Unlike the former control, the state feedback control is unable to make the body side-slip angle vanish. The feedback control performance of each of the two moment actuators has been examined separately and then jointly. The advantages of combining the open loop and feedback dual actuator configurations are demonstrated using the two-degree of freedom control scheme. It is found that the scheme yields a spectacular performance but demands unreasonably large moments from the actuators in the context of available aerodynamic forces. On the other hand, the demand on direct yaw and roll moment of actuators is modest when the actuators are controlled using the LQR feedback only and if the control design is used to track a desired yaw rate trajectory and simultaneously to reduce the parasitic rolling motion. Significant improvements in handling and dynamic stability of a base-line vehicle can be achieved by aerodynamically generated direct yaw and roll actuator moments provided the target control performance is reasonable. The configurations of aerodynamic actuators considered are feasible for improving vehicle handling in cornering on motorways but more work remains to be done to explore alternative aerodynamic configurations that give rise to less side effects and higher lift coefficients.     

Application of Aerodynamic Actuators to Improve Vehicle Handling

This exploratory study considers applications of active aerodynamic devices for suppressing parasitic motion and for improving the response of vehicles to steering, within the scope of the linear dynamic behaviour. A three DOF linear model is chosen to describe the side slip, yaw and roll motion of a baseline front-wheel steered vehicle. The improvements in performance of the base-line vehicle that are achievable by the application of direct yaw and roll moments are determined when either an open loop control pre-filter or a state feedback control law based on LQR design is applied. Unlike the former control, the state feedback control is unable to make the body side-slip angle vanish. The feedback control performance of each of the two moment actuators has been examined separately and then jointly. The advantages of combining the open loop and feedback dual actuator configurations are demonstrated using the two-degree of freedom control scheme. It is found that the scheme yields a spectacular performance but demands unreasonably large moments from the actuators in the context of available aerodynamic forces. On the other hand, the demand on direct yaw and roll moment of actuators is modest when the actuators are controlled using the LQR feedback only and if the control design is used to track a desired yaw rate trajectory and simultaneously to reduce the parasitic rolling motion. Significant improvements in handling and dynamic stability of a base-line vehicle can be achieved by aerodynamically generated direct yaw and roll actuator moments provided the target control performance is reasonable. The configurations of aerodynamic actuators considered are feasible for improving vehicle handling in cornering on motorways but more work remains to be done to explore alternative aerodynamic configurations that give rise to less side effects and higher lift coefficients.     

基于QFT的四轮转向控制系统设计

本文提出一种基于定量反馈理论的主动控制四轮转向策略，以汽车转向时的横摆角速度和车体侧偏角为被控制量，将汽车的速度、质量、轮胎等效侧偏刚度等参数视为有界的不确定参数，应用定量反馈理论（QFT）设计反馈控制系统。为了验证设计的有效性，采用具有非线性轮胎特性的汽车模型对控制系统作了多种工况下的仿真。仿真结果证明所设计的解耦控制系统对汽车参数的不确定性具有鲁棒性，同时具有较好的控制特性，能够有效提高汽车的主动安全性和操纵稳定性。     

Lateral handling improvement with dynamic curvature control for an independent rear wheel drive EV

The integrated longitudinal and lateral dynamic motion control is important for four wheel independent drive (4WID) electric vehicles. Under critical driving conditions, direct yaw moment control (DYC) has been proved as effective for vehicle handling stability and maneuverability by implementing optimized torque distribution of each wheel, especially with independent wheel drive electric vehicles. The intended vehicle path upon driver steering input is heavily depending on the instantaneous vehicle speed, body side slip and yaw rate of a vehicle, which can directly affect the steering effort of driver. In this paper, we propose a dynamic curvature controller (DCC) by applying a the dynamic curvature of the path, derived from vehicle dynamic state variables; yaw rate, side slip angle, and speed of a vehicle. The proposed controller, combined with DYC and wheel longitudinal slip control, is to utilize the dynamic curvature as a target control parameter for a feedback, avoiding estimating the vehicle side-slip angle. The effectiveness of the proposed controller, in view of stability and improved handling, has been validated with numerical simulations and a series of experiments during cornering engaging a disturbance torque driven by two rear independent in-wheel motors of a 4WD micro electric vehicle.