汽车主动悬挂控制的研究现状和未来挑战

主动悬挂系统能提高车辆的乘坐舒适性和操纵性,得到了广泛的研究和重视.掌握悬挂控制的研究现状,可以更好地研究和利用主动悬挂技术.本文立足现有文献,依照不同的控制策略,从七个方面阐述了主动悬挂控制的研究现状,总结出了尚需解决的非线性悬挂建模、悬挂集成控制、控制系统性能评估等六个基本问题.文章最后分析了鲁棒控制、自适应控制、智能控制在车辆悬挂控制中的局限性及出现的挑战性课题,提出了车辆主动悬挂技术的发展方向.     

基于反向递推的主动悬架控制设计与仿真

车辆悬架系统是典型的非线性系统,反向递推(Backstepping)控制理论适用于非线性系统的控制.本文建立了基于反向递推控制策略的车辆主动悬架模型,证明了该主动悬架系统具有全局渐进稳定特性,能实现突遇路面冲击时防止发生悬架击穿之目的.对某型车辆单轮悬架的越障案例进行了仿真研究,结果表明:当车辆驶过路面突起时,采用所提出的反向递推控制策略的主动悬榘系统的性能优于最优控制主动悬架和被动悬架系统,避免了悬架击穿.     

履带车辆半主动悬架控制系统硬件设计

研究了履带式车辆单轮悬挂模型的车体加速度均方根值特性，提出了一种最优阻尼的控制策略，同时给出了按此控制策略研制的履带式车辆半主动悬架控制系统的硬件设计及其典型特点。经过实际的试验，进一步证实了半主动悬挂系统能有效地减小车体的加速度均方根值，从而提高了车辆平顺性。     

履带车辆半主动悬挂多体及控制联合仿真研究

在履带车辆悬挂系统线性振动模型基础上,证明了悬挂最优阻尼比的存在,提出了统计意义上的最优阻尼控制策略,即为履带车辆悬挂半主动控制的理论基础。通过基于多体动力学理论的虚拟样机方法对某型履带车辆整车悬挂系统进行了仿真研究,结合“机械系统＋控制系统”联合仿真技术,对比了该车分别采用被动悬挂和半主动悬挂时的动力学特性,得出了该履带车辆采用半主动悬挂可显著降低车辆振动加速度,提高车辆乘坐舒适性的结论。从而验证了多体理论和联合仿真技术在履带车辆半主动悬挂技术的可行性。     

具有输入时滞的主动悬挂系统的减振控制

研宄具有输入时滞的汽车主动悬挂系统在路面扰动下的减振控制器设计问题.首先根据汽车悬挂系统的特点,从实用性的角度出发化简了悬挂系统的数学模型.然后提出一种变量代换方法,将具有输入时滞的主动悬挂系统转换为形式上不含时滞的系统.针对转换后的无时滞系统,设计出具有输入时滞的主动悬挂系统减振控制器:又从控制器的成本和易实现性出发添加了一个状态观测器.在这种系统结构下,设计出一种具有记忆和积分特性的主动悬挂系统减振控制策略.仿真结果验证了这种设计控制器的方法是有效的.     

线控转向系统的主动转向控制策略研究

线控转向系统取消了转向盘和转向轮之间的机械连接,可以对前轮进行主动转向控制以增强操纵稳定性和主动安全性.通过使前轮线控转向系统的期望横摆角速度跟踪稳态质心侧偏角为0的四轮转向车辆的横摆角速度,设计线控转向系统的变传动比,主动控制前轮转角.通过时域响应、转向增益、开环总方差等指标对其进行了性能分析.结果表明:采用提出的主动转向控制策略时稳态质心侧偏角大大降低,开环总方差大大降低,从而提高了汽车的操纵稳定性.     

高速铁道车辆悬挂系统参数化建模、优化与仿真分析

为了协调高速铁道车辆的运动稳定性与曲线通过性能之间的矛盾,本文采用多目标优化方法对一种高速铁道车辆的关键悬挂参数进行了优化处理.采用多体动力学技术建立了某型高速铁道车辆62个自由度的动力学模型,模型考虑了轮轨接触几何非线性、轮轨蠕滑非线性和阻尼非线性等.采用ADAMS-Matlab联合仿真对车辆悬挂系统进行参数化改造,使弹簧刚度和阻尼系数均可调.采用基于遗传算法的多目标优化方法对悬挂参数进行优化,使车辆模型能同时满足3种动力学指标.对比优化前后模型的动力学性能可以发现:模型的运动稳定性和曲线通过性能得到显著提高,虽然运行平稳性有小幅降低,但仍能保持在优良的工作状态.     

引入乘客动力学的1/2车辆液压主动悬挂系统建模与控制

建立了引入乘客动力学以及考虑液压装置动态特性的1/2车辆非线性主动悬挂模型，并在此模型的基础上提出了线性二次型最优控制与非线性Backstepping方法相结合的控制策略．仿真结果验证了该控制策略的有效性．     

高速列车转向架的主动稳定性研究

提出了基于构架横向振动的高速列车稳定性主动控制方法,讨论了采用惯性作动器控制构架横向振动,以及对动力转向架驱动系统采用主动弹性悬挂这两种实施方式.以车辆蛇行稳定性指标和控制力作为两个目标函数,利用遗传算法(NSGA-II)来优化控制参数和驱动系统悬挂参数.研究表明构架横向振动控制可以有效地提高转向架蛇行稳定性.同时发现当直接反馈构架状态实现构架振动控制时,控制系统时滞易导致系统失稳,因此提出一种通过反馈附加振子状态的方法来减小时滞的影响,合理的附加振子悬挂参数有利于提高车辆系统稳定性.较硬的附加振子可提高转向架控制系统的蛇行临界速度裕度,但会导致控制系统在一定的时滞内出现不稳定的现象.因此,在优化附加振子悬挂参数时,必须同时兼顾转向架蛇行稳定性和控制系统稳定性.本文对于涉及的350 km/h高速列车转向架,得出了附加振子的最佳固有频率和阻尼比.     

主动前轮独立转向系统分析与研究

为了提高车辆的操稳性,提出了新型主动前轮独立转向系统,介绍了主动前轮独立转向的工作原理和结构形式,建立了系统数学模型;提出了主动前轮独立转向的控制策略,上层控制器采用PI控制,由横摆角速度偏差得出总控制转角,下层控制器负责内外侧转向轮的判断以及计算内外侧转向轮具体的转角;在仿真软件MATLAB/Simulink里进行了控制策略有效性仿真,仿真结果说明对于不足转向车辆,主动前轮独立转向系统能比传统的主动前轮转向系统更有效地提高车辆操纵稳定性。     

MODELING AND CONTROL OF THE ACTIVE SUSPENSION SYSTEM USING PROPORTIONAL INTEGRAL SLIDING MODE APPROACH

The purposes of this paper are to present a new method in modeling an active suspension system for half‐car model in state space form and to develop a robust strategy in controlling the active suspension system. Proportional integral sliding mode control strategy is proposed for the system. A simulation study is performed to prove the effectiveness and robustness of the control approach and performance of the controller is compared to the linear quadratic regulator and the existing passive suspension system.     

Vibration control of a nonlinear quarter-car active suspension system by reinforcement learning

This article presents the investigation of performance of a nonlinear quarter-car active suspension system with a stochastic real-valued reinforcement learning control strategy. As an example, a model of a quarter car with a nonlinear suspension spring subjected to excitation from a road profile is considered. The excitation is realised by the roughness of the road. The quarter-car model to be considered here can be approximately described as a nonlinear two degrees of freedom system. The experimental results indicate that the proposed active suspension system suppresses the vibrations greatly. A simulation of a nonlinear quarter-car active suspension system is presented to demonstrate the effectiveness and examine the performance of the learning control algorithm.     

A class of proportional-integral sliding mode control with application to active suspension system

The purpose of this paper is to present a new robust strategy in controlling the active suspension system. The strategy utilized the proportional-integral sliding mode control scheme. A quarter-car model is used in the study and the performance of the controller is compared to the linear quadratic regulator and with the existing passive suspension system. A simulation study is performed to prove the effectiveness and robustness of the control approach.     

Genetic-based fuzzy control for half-car active suspension systems

In this paper, a fuzzy controller is designed for automotive active suspension systems. A half-car model is used in order to consider the pitch angle of the body and the coupling dynamics of front and rear wheels. It is assumed that the three measurements of body acceleration, front suspension deflection and rear suspension deflection are available. The fuzzy control rules are separately designed for each measurement. After the fuzzy control rules are determined, a genetic algorithm is applied to tune the membership functions of these control rules. To measure the performance of the designed genetic-based fuzzy active suspension system, three road disturbance models are designed to simulate actual road conditions. The performance of the designed system is evaluated with respect to these disturbance models, and it is shown that the designed active suspension system provides good performance in improving ride quality and maintaining vehicle maneuvrability. It is also shown that the designed active suspension system shows robust performance with system model uncertainties.     

基于模糊控制的汽车主动悬架仿真研究

本文建立了汽车振动的四分之一车体悬架模型和悬架系统的振动微分方程,并利用Matlab／Simulink软件实现了两自由度主动悬架的仿真模型。应用传递函数方法,对主动悬架在不同路况下的控制策略进行了深入研究,给出了相应的模糊控制策略,并进行仿真实验。仿真结果表明,装备了主动悬架的整车与被动悬架控制相比,前者在很大程度上降低了车身加速度、悬架动挠度和轮胎的相对动载荷,从而有效地提高了汽车的乘坐舒适性和操纵稳定性。     

应用轴距预描的主动悬架最优控制器设计

设计主动悬架的关键任务之一是寻找一个好的控制律，随机线性最优控制理论能为车辆提供良好的性能，得到了广泛的应用。轴距预描控制利用前轮处的路面信息作为预描变量对后轮进行控制，能充分发挥主动悬架的潜力。该文以悬架理论为基础，应用最优控制理论进行了结合轴距预瞄信息的主动悬架最优控制器的设计，并用一个卡尔曼滤波器估计系统状态。最后在MATLAB环境中建模和仿真，将有、无预描主动悬架系统的车身加速度、悬架动行程及车轮动位移3项指标进行了对比。仿真结果表明，采用轴距预描控制在低速情况下能较大改善后悬架系统的性能．验证了轴距预描控制的可行性。     

Active control for the suspension of large-sized buses using fuzzy logic

An active suspension of large-sized buses by using fuzzy logic is considered. The active control for the suspension is determined by minimizing the mean squares of vertical and rotary accelerations of vehicle body subject to the constraints of suspension and tyre deflections. The vehicle model is assumed to be a linear system with six degrees of freedom excited by road profiles. The tuning of fuzzy control rules and associated parameters that characterize the active control is carried out where two kinds of road profiles are considered. In the simulation results, the proposed active suspension shows improved performance over passive suspension     

Design of a grey-prediction self-organizing fuzzy controller for active suspension systems

Self-organizing fuzzy controllers (SOFCs) have excellent learning capabilities. They have been proposed for the manipulation of active suspension systems. However, it is difficult to select the parameters of an SOFC appropriately, and an SOFC may extensively modify its fuzzy rules during the control process when the parameters selected for it are inappropriate. To eliminate this problem, this study developed a grey-prediction self-organizing fuzzy controller (GPSOFC) for active suspension systems. The GPSOFC introduces a grey-prediction algorithm into an SOFC, in order to pre-correct its fuzzy rules for the control of active suspension systems. This design solves the problem of SOFCs with inappropriately chosen parameters. To evaluate the feasibility of the proposed method, this study applied the GPSOFC to the manipulation of an active hydraulic-servo suspension system, in order to determine its control performance. Experimental results demonstrated that the GPSOFC achieved better control performance than either the SOFC or the passive method of active suspension control.     

A New SSUKF Observer for Sliding Mode Force Tracking H∞ Control of Electrohydraulic Active Suspension

Compared to passive and semi‐active suspensions, active suspensions have the capacity to overcome the tradeoff design of vehicle ride comfort and handling performance. In this paper, a new control system with modified spherical simplex UKF (SSUKF) observer and sliding mode force tracker is proposed for electrohydraulic active suspensions. The estimated states obtained from the SSUKF observer are used to derive the mode energy of body motion and design the target demanded forces for suspension actuators. A sliding mode controller is presented to drive electrohydraulic actuators to track the demanded forces. Based on a robust H∞ control method, a new control strategy depending on body mode energy is proposed to restrict body motion. The performance comparisons between passive and active suspensions under three typical excitations are presented, and the obtained results indicate that the proposed control system can significantly depress body motion and decrease the mode energy to improve ride comfort and also effectively enhance the road hold abilities.     

分数微积分理论在非线性车辆悬架滑模控制中的应用

基于分数微积分理论,提出分数阶”天棚”阻尼控制概念,并以它控制的悬架为参考模型,提出一个控制效果理想、鲁棒性好的悬架滑模控制的新策略,并应用于非线性悬架的动力学控制中．文中给出了一种精度较高,收敛稳定的分数阶系统的数值算法,最后对非线性悬架的滑模主动控制进行数值仿真,验证了新控制策略优良的控制效果．