汽车主动悬架的最优预见控制

本文针对1/2车辆模型,应用最优预见控制理论对汽车主动悬架进行控制系统的设计和研究。计算机仿真结果表明,所提出的系统能有效改善汽车乘坐舒适性。     

Optimal Linear Preview Control of Active Vehicle Suspension

SUMMARY

The problem of linear preview control of vehicle suspension is considered as a continuous time stochastic optimal control problem. In the proposed approach minimal a priori information about the road irregularities is assumed and measurement errors are taken into account. It is shown that estimation and control issues can be decoupled. The problem formulation and the analytical solution are given in a general form and hence they apply to other problems in which the system disturbances are unknown a priori, even in a stochastic sense, but some preview information is possible.

The solution is applied to a two-degree-of-freedom (2-DOF) vehicle model. The effects of preview information on ride comfort, road holding, working space of the suspension and power requirements are examined in time and frequency domains. The results show that the greatest potential is for improving road holding properties. This effect could not have been observed in previous studies based on a 1-DOF vehicle model. It is also demonstrated that the presence of preview drastically reduces power requirements, thus relieving the performance versus actuator power dilemma.     

Optimal Linear Preview Control of Active Vehicle Suspension

The problem of linear preview control of vehicle suspension is considered as a continuous time stochastic optimal control problem. In the proposed approach minimal a priori information about the road irregularities is assumed and measurement errors are taken into account. It is shown that estimation and control issues can be decoupled. The problem formulation and the analytical solution are given in a general form and hence they apply to other problems in which the system disturbances are unknown a priori, even in a stochastic sense, but some preview information is possible.

The solution is applied to a two-degree-of-freedom (2-DOF) vehicle model. The effects of preview information on ride comfort, road holding, working space of the suspension and power requirements are examined in time and frequency domains. The results show that the greatest potential is for improving road holding properties. This effect could not have been observed in previous studies based on a 1-DOF vehicle model. It is also demonstrated that the presence of preview drastically reduces power requirements, thus relieving the performance versus actuator power dilemma.     

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。     

Preview Control Algorithms for the Active Suspension of an Off-Road Vehicle

The potential performance improvement using preview control for active vehicle suspension was first recognized in the late nineteen sixties. All work done since that time has been based on optimal control theory using simple vehicle models.

In this article, the performance of quarter vehicle preview controllers when applied to a real off-road vehicle is simulated using both two degree of freedom quarter and ten degree of freedom full vehicle models. The results, which are compared with non-preview active and conventional passive suspensions, confirm that preview control reduces vertical acceleration of the body centre of gravity, which results in improved ride quality. Further, reductions in pitch and roll motion result from smaller vertical displacements of the vehicle quarters. Coupling between quarters, through the vehicle body, appears to have a smoothing effect on the control.

As an alternative to optimal control theory based controllers, a simple ad hoc preview controller based on isolating the vehicle body from dynamic loads transmitted through the suspension is proposed. Simulation results show that such a controller outperforms the optimal control theory based controllers over small discrete disturbances but responds poorly to disturbances encountered from other than steady state.     

结合卡尔曼滤波器的车辆主动悬架轴距预瞄控制研究

利用轴距预瞄信息，即前后轮路面输入之关系，同时结合卡尔曼滤波器作为状态估计器，本文提出了一种算法用于车辆悬架控制律的设计，根据模拟结果，研究了算法的可行性，分析了卡尔曼滤波器对状态变量的估计精度，以及轴距预瞄控制对进一步改进车辆性能的潜力。     

Performance Index for a Preview Active Suspension Applied to a Quarter-Car Model

A simple and convenient matrix expression is derived for the performance index in the case of a linear vehicle model with two degrees of freedom and a preview active suspension, subject to a unit step road input and employing optimal control. The usual quadratic integral-type performance index is assumed and the effect of an additional form of constraint is described briefly. The effects of preview time on the performance index and the optimal feed-forward control are illustrated graphically for a particular example.     

Performance Index for a Preview Active Suspension Applied to a Quarter-Car Model

A simple and convenient matrix expression is derived for the performance index in the case of a linear vehicle model with two degrees of freedom and a preview active suspension, subject to a unit step road input and employing optimal control. The usual quadratic integral-type performance index is assumed and the effect of an additional form of constraint is described briefly. The effects of preview time on the performance index and the optimal feed-forward control are illustrated graphically for a particular example.     

基于预测控制和频率成型性能指标的主动悬架控制策略研究

预测控制（包括轴距时间延迟）具有改善系统动态性能的能力，对性能指标的频率成型则可以改善乘坐舒适性。结合以上两种方法，提出了一种算法用于主动悬架控制策略的设计，并在时域和频域利用此算法对一个五自由度主动悬架车辆模型进行仿真，检验了算法的可行性和控制效果。     

主动油气悬架试验模型的研制

文章重点介绍了一个二自由度主动悬研制情况。该模型于１９９７年１０月在清华大学汽车工程系统建成，成功地进行了多种主动悬架控制策略的试验和验证工作得到了较好的结果，为后续研究工作的顺利进行提供了良好的试验手段。     

汽车主动悬架与电动助力转向系统多目标优化及集成控制

建立了整车主动悬架和电动助力转向系统动力学模型,构建线性控制的主动悬架和PD控制的电动助力转向系统集成控制器,应用遗传算法对集成控制系统的结构参数和控制参数进行多目标优化。结果表明,经过多目标优化后的集成控制系统,既可保证车辆操纵轻便性,又显著提高了整车操纵稳定性、安全性和行驶平顺性。     

主动悬架系统控制策略研究

文章设计一种主动悬架控制策略,通过建立四分之一车辆主动悬架系统模型,设计模糊滑模控制策略对主动悬架系统进行控制,并使用Matlab/Simulink软件对所建立的模型进行仿真分析。通过仿真结果验证了所建模型和控制策略的准确性,同时也改善了悬架系统的性能。     

汽车半车主动悬架的最优控制研究

本文运用车辆动力学理论,建立了半车四自由度主动悬架系统的动力学模型。同时依据最优控制理论设计了主动悬架最优控制器并进行了Matlb+simulink仿真。研究结果表明采用最优控制的主动悬架比被动悬架具有更好的平顺性。     

车辆主动悬架系统的LMS自适应控制

选择LMS自适应滤波算法，通过调整自适应滤波器的权系数使二次性能指标达最小，根据单个样本方差的负梯度来调节权系数；得到控制输出。针对简化的车辆模型，将空钩控制、广义自适应控制与LMS自适应控制相对比。仿真计算表明，主动悬架系统LMS自适应控制策略不仅计算简单，而且理论上在主动悬架系统中的应用是切实可行的，性能明显优于其它对比控制方法。     

Optimization and Performance Enhancement of Active Suspensions for Automobiles under Preview of the Road

The problem of deriving control laws which minimize specified performance indices for a vehicle moving on a rough surface with preview of the surface elevation is considered. The approach is based on linear optimal tracking theory and consequently the system elements are taken to be linear and the performance index is constrained to be of quadratic form.

The ideas of overtaking optimality are applied to the problem in order to achieve a closed form solution for the control. Then, using the control laws derived, computer simulations of performance are conducted and time histories are shown. In the absence of limitations on either processing or actuator speeds, and for cases in which the preview is sufficient to give good control laws, the value of the preview in enhancing vehicle suspension performance is assessed. Comparisons are made with results in the literature.     

基于轴间预瞄的主动悬架研究

以某型汽车的1／2车辆模型为研究对象，提出了一种轴间预瞄控制的方法，并结合最优控制理论设计了车辆悬架的控制策略。通过模拟和仿真分析，验证了所提出的轴间预瞄比传统的轴距预瞄具有更好的控制效果。     

主动悬架系统对汽车制动性能改善分析

针对汽车制动过程中质量转移而使最大制动力下降的问题，提出利用主动悬架系统减小汽车动态车轮载荷的方法。通过模拟分析得到，利用主动悬架系统可以有效降低汽车由于质量转移而引起车轮动态轴荷的改变量，限制了汽车最大制动力的下降，是解决制动力下降的一个比较有效的方法。     

汽车主动悬架最优控制：采用频域计权形式性能指标函数

本文从提高汽车的乘坐舒适性角度出发，研究了主动悬架的最优控制问题。根据坐位人体的振动响应特性构造了频域计权形式二交型性能指标函数。     

基于11自由度列车车辆模型的主动悬挂预见控制研究

讨论了预见控制在列车车辆主动悬挂系统中的应用，分析了预见控制的设计方法，指出如何利用未来信息，在一个11个自由度的列车车辆模型的基础上对预见控制进行仿真研究，结果表明预见控制具有良好的控制效果。     

采用电磁直线电机的主动悬架控制系统的设计与能量分析

针对因特殊的动力布置形式导致的轮边驱动电动汽车操稳性和平顺性之间冲突,本文中提出了一种新式电磁直线电机式悬架系统的主动控制系统。考虑到其能量回收性能不佳的弊端,基于LQR控制设计了一种包含能量管理单元的能量回收控制器,并在Matlab/Simulink中对整个系统进行了仿真。结果表明,所设计的能量回收控制器不仅能够改善汽车的操稳性和平顺性,而且能有效回收汽车悬架的振动能量。