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。     

汽车主动悬架系统建模及其控制策略研究

介绍了一种主动悬架系统的建模，该系统是由液压作动器与一个普通弹簧串联后，再与被动阻尼器并联构成。其通常又被称作慢主动悬架。并应用SIMULINK语言仿真，确定了实际可行的输出反馈方案。     

基于闭环力反馈原理的非线性液压主动阻尼悬架模型的研究及优化设计

本文在理论上建立了一套基于主动力反馈原理的新型主动阻尼悬架的设计和优化方法。首先提出了该主动阻尼悬架的实现模型，该模型是在传统的液力减振器的基础上，应用半主动控制的思想，结合力反馈的原理建立起来的内部液压反馈阻尼网络模型。理论优化分析和计算机仿真表明，通过该液阻网络模型，即可以实现电控的主动阻尼悬架的功能，它可以根据汽车行驶路况的好坏，自适应地调节悬架阻尼大小以实现主动阻尼悬架的最优控制。     

主动悬架系统对汽车侧翻稳定性改善分析

针对被动悬架系统侧翻稳定性比较差的问题,提出采用主动悬架系统的方法进行改善。通过汽车侧倾运动状态分析,建立了被动悬架系统、主动悬架系统和控制系统模型。模拟分析得到主动悬架系统使得汽车在弯道行驶时的侧倾角有效值下降了92.8%,侧倾角加速度有效值下降了78.2%,侧翻因子有效值下降了92.6%。结果表明:利用主动悬架系统可以有效地降低汽车非直线行驶时的侧倾角以及侧倾角加速度,提高汽车的侧翻稳定性,是提高汽车非直线行驶状态下安全性的一个合理的解决方案。     

主动悬架系统对汽车侧翻稳定性改善分析

针对被动悬架系统侧翻稳定性比较差的问题,提出采用主动悬架系统的方法进行改善。通过汽车侧倾运动状态分析,建立了被动悬架系统、主动悬架系统和控制系统模型。模拟分析表明,主动悬架系统使得汽车在弯道行驶时的侧倾角有效值下降了92.8%,侧倾角加速度有效值下降了78.2%,侧翻因子有效值下降了92.6%。结果表明:利用主动悬架系统可以有效地降低汽车非直线行驶时的倾角以及侧倾角加速度,提高汽车的侧翻稳定性,是提高汽车非直线行驶状态下安全性的一个合理的解决方案。     

丰田LEXUSLS400型轿车的电子控制悬架

简要介绍了半主动，全主动及慢全主动汽车悬架系统的性能和目前应用情况。以丰田公司生产的凌志ＬＳ４００型轿车的悬架为例，详细分析了上前在高档轿车上的应用较多的半主动电子控制悬架的结构和工作原理，以及该系统的故障自诊功能和失效保护功能。     

轿车悬架技术现状与发展趋势

介绍了轿车用被动悬架、半主动悬架、主动悬架的结构特点和工作原理，以及各自的优缺点与发展趋势。通过比较分析得出：被动悬架因结构简单、性能可靠、成本低、不耗能而得到广泛应用；主动悬架虽性能优越，但因元件价格昂贵，工作时能耗高而使其应用受到限制；半主动悬架性能好于被动悬架，且成本比主动悬架低得多，是今后悬架系统的主要发展方向。     

主动悬架系统对汽车侧翻稳定性的改善分析

针对被动悬架系统侧翻稳定性较差的问题,提出采用主动悬架系统的方法进行改善.通过汽车侧倾运动状态分析,建立了被动悬架系统、主动悬架系统和控制系统模型.模拟分析表明,主动悬架系统使汽车在弯道行驶时的侧倾角有效值下降92.8%,侧倾角加速度有效值下降78.2%,侧翻因子有效值下降92.6%.结果表明,利用主动悬架系统可有效降低汽车非直线行驶时的侧倾角及侧倾角加速度,提高汽车的侧翻稳定性,采用主动悬架系统是提高汽车非直线行驶状态下安全性的一个合理的解决方案.     

基于微分几何理论的汽车半主动悬架非线性振动控制

针对汽车悬架系统的非线性特性,采用1／4汽车二自由度悬架模型分析半主动悬架控制。应用微分几何理论得到输出-干扰解耦方法,再经适当的坐标变换将该模型由非线性系统简化成一线性系统,并对此系统进行最优控制,然后通过非线性状态反馈实现对原系统的半主动控制。与被动悬架的仿真结果进行了比较,表明这种针对具有非线性特征的半主动悬架的非线性控制方法是可行的。通过功率谱分析,控制后系统的能量比被动悬架更趋于平均,悬架动态性能更稳定。     

汽车悬架控制技术的发展

现代汽车悬架，要求其在各种行驶条件下提供平顺性和安全性的最佳匹配。但是传统被动悬架，只能保证在一种特定道路和速度下达到最优折衷。为此，开发研制了各种悬架控制技术和方案。介绍了半被动、半主动、慢全主动、全主动四种悬架控制方案和应用，并作了相应的评价。     

Optimal Adaptive Active Suspensions for a Full Car Model

In order to present a useful method for designing active suspension of a vehicle, a linear full-car model is used in this investigation. In this model, the dampers of passive system are totally replaced by actuators. The actuators are controlled with optimal full state vector feedback. After determining feedback coefficients, the responses of active and passive systems were compared and it was found that performance of active system is much superior. It is desired that, changes in vehicle parameters would not affect the system's performance and hence should not violate its optimality. In other words, the system should behave adaptively using Model Reference Adaptive Control. The optimally controlled active suspension was used as a model for the active suspension of vehicle. In this way, the suspension of vehicle is controlled in such a way that its output approaches to that of the optimal active model. Thus the suspension should behave just like the optimal one.     

Optimal Performance of Variable Component Suspensions

Most vehicle suspension systems use fixed passive components that offer a compromise in performance between sprung mass isolation, suspension travel, and tireroad contact force. Recently, systems with discretely adjustable dampers and air springs been added to production vehicles. Active and semi-active damping concepts for vehicle suspensions have also been studied theoretically and with physical prototypes. This paper examines the optimal performance comparisons of variable component suspensions, including active damping and full-state feedback, for “quartercar” heave models. Two and three dimensional optimizations are computed using performance indicators to find the component parameters (control gains) that provide “optimal” performance for statistically described roadway inputs. The effects of performance weighting and feedback configuration are examined. Active damping is shown to be mainly important for vehicle isolation. A passive vehicle suspension can control suspension travel and tire contact force nearly as well as a full state feedback control strategy.     

Optimal Performance of Variable Component Suspensions

SUMMARY

Most vehicle suspension systems use fixed passive components that offer a compromise in performance between sprung mass isolation, suspension travel, and tireroad contact force. Recently, systems with discretely adjustable dampers and air springs been added to production vehicles. Active and semi-active damping concepts for vehicle suspensions have also been studied theoretically and with physical prototypes. This paper examines the optimal performance comparisons of variable component suspensions, including active damping and full-state feedback, for “quartercar” heave models. Two and three dimensional optimizations are computed using performance indicators to find the component parameters (control gains) that provide “optimal” performance for statistically described roadway inputs. The effects of performance weighting and feedback configuration are examined. Active damping is shown to be mainly important for vehicle isolation. A passive vehicle suspension can control suspension travel and tire contact force nearly as well as a full state feedback control strategy.     

Design of active suspension and electronic stability program for rollover prevention

This paper presents a method for the design of a controller for rollover prevention using active suspension and an electronic stability program (ESP). Active suspension is designed with linear quadratic static output feedback control methodology to attenuate the effect of lateral acceleration on the roll angle and suspension stroke via control of the suspension stroke and tire deflection of the vehicle. However, this approach has a drawback in the loss of maneuverability because the active suspension for rollover prevention produces in vehicles an extreme over-steer characteristic. To overcome this drawback of the active suspension based method, ESP is designed. Through simulations, the proposed method is shown to be effective in preventing rollover.     

Fuzzy adaptive sliding mode controller for an air spring active suspension

A fuzzy adaptive sliding mode controller for an air spring active suspension system is developed. Due to nonlinearity, preload-dependent spring force and parameter uncertainty in the air spring, it is difficult to control the suspension system. To achieve the desired performance, a fuzzy adaptive sliding mode controller (FASMC) is designed to improve the passenger comfort and the manipulability of the vehicle. The fuzzy adaptive system handles the nonlinearity and uncertainty of the air suspension. A normal linear suspension model with an optimal state feedback control is designed as the reference model. The simulation results show that this control scheme more effectively and robustly isolates vibrations of the vehicle body than the conventional sliding mode controller (CSMC).     

Preview suspension control for a full tracked vehicle

In this study, preview control algorithms for the active and semi-active suspension systems of a full tracked vehicle (FTV) are designed based on a 3-D.O.F model and evaluated. The main issue of this study is to make the ride comfort characteristics of a fast moving tracked vehicle better to keep an operator’s driving capability. Since road wheels almost trace the profiles of the road surface as long as the track doesn’t depart from the ground, the preview information can be obtained by measuring only the absolute position or velocity of the first road wheel. Simulation results show that the performance of the sky-hook suspension system almost follows that of full state feedback suspension system and the on-off semi-active system carries out remarkable performance with the combination of 12 on-off semi-active suspension units. The results simulated with 1^st and 2^nd weighting sets mean that the suspension system combined with the soft type of inner suspension and hard type of outer suspension can carry out better ride comfort characteristics than that with identical suspensions. The full tracked vehicle (FTV) system is uncontrollable and the system is split into controllable and uncontrollable subspace using singular value decomposition transformation. Frequency response curves to four types of inputs, such as heaving, pitching, rolling, and warping inputs, also demonstrate the merits of preview control in ride comfort. All the frequency characteristic responses confirm the continuous time results.     

电液主动悬架滤波输出反馈控制器的设计及仿真实现

基于1／2车辆模型和非线性电液作动器，提出并详细设计了主动悬架滤波输出反馈控制器。整个主动悬架系统分解为内、外两个回路，外回路采用滤波输出反馈控制，大幅度衰减了车辆在高低频范围内的起伏和俯仰运动，提高了车辆的乘坐舒适性。内回路基于非线性作动器模型，采用传统的PI控制器，较好地跟踪输出了控制系统需要的作用力。此外，还对作动系统的摩擦力进行了详细建模。频域和时域仿真结果演示了主动悬架的良好性能并验证了结论。     

考虑路面不平度的汽车稳定性控制的研究

考虑路面不平度对汽车稳定性的影响，建立了一个含路面不平度激励的14自由度的汽车动力学模型。在主动悬架技术的基础上，运用直接的反馈控制制定了提高汽车操纵稳定性的控制策略。利用该模型进行了汽车稳定性的仿真研究。与没有稳定性控制系统的仿真结果相比，该控制器的应用能够较好地改善汽车的稳定性。     

Optimal Preview Control of a Two-dof Vehicle Model Using Stochastic Optimal Control Theory

An optimal preview control algorithm is applied to a two degree of freedom(dof) vehicle model travelling with constant velocity on a randomly profiled road. The road roughness is modelled as a homogeneous random process being the output of a linear first order filter to white noise. The input from the road irregularity is assumed to be measured at some distance in front of the vehicle and this measured infonnation is utilized by the active controller to prepare the system for the ensuing input. The preview control algorithm is obtained by minimizing a quadratic performance index and by describing the average behaviour of the system by the covariance matrix of the vehicle response state vector. Results are presented for full state feedback and significant improvements in sprung mass acceleration, suspension working space and road holding are observed.