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．     

基于神经网络自适应控制的主动悬挂系统

该文给出了利用神经网络对主动悬挂系统进行自适应控制的方法，分析在不同的参数条件下的系统响应，仿真结果表明，用这种控制算法能对存在未知参数和变化参数的主动悬挂系统有很好的控制效果。     

具有状态参数约束的鲁棒自适应最优控制设计

在传统Backstepping鲁棒自适应设计中,虚拟控制函数的设计参数缺乏约束,对此,采用新的设计方法得到了新坐标系下的系统模型和参数替换律,结合直接反馈线性化和最优控制策略,最终给出了具有参数约束的非线性鲁棒自适应最优控制的设计方法.以具体励磁系统参数为例进行仿真实验研究,所得结果表明,该鲁棒自适应控制方法可以实现状态参数的最优约束,并能有效控制状态参数的收敛速度.     

具有状态参数约束的鲁棒自适应最优控制设计

在传统Backstepping 鲁棒自适应设计中, 虚拟控制函数的设计参数缺乏约束, 对此, 采用新的设计方法得到了新坐标系下的系统模型和参数替换律, 结合直接反馈线性化和最优控制策略, 最终给出了具有参数约束的非线性鲁棒自适应最优控制的设计方法. 以具体励磁系统参数为例进行仿真实验研究, 所得结果表明, 该鲁棒自适应控制方法可以实现状态参数的最优约束, 并能有效控制状态参数的收敛速度.     

基于自适应Backstepping的飞机重心变化稳定控制律设计

飞机重心变化会影响飞机气动力从而产生较强的扰动误差,可以采用自适应Backstepping控制方法消除这种扰动误差对飞行控制的影响。首先建立飞机重心位置和重量变化的非线性模型,然后设计自适应Backstepping控制律,对模型误差进行自适应估计,针对f16飞机纵向操纵力矩不是仿射非线性的形式,采用牛顿迭代法进行求解,最后进行正常情况下、重心突变和重心渐变情况下的仿真验证,仿真结果表明设计的自适应Backstepping控制律具有很好的动态和稳态性能。     

基于Backstepping方法的MIMO过程分散PID控制器设计

A novel decentralized PID controller design procedure based on backstepping principles is presented to operate multiple-input multiple-output (MIMO) dynamic processes. The first key feature of the design procedure is that a whole MIMO control system is decomposed into multiple control loops, therefore the sub-controllers can be efficiently flexibly designed in parallel prototype. The second key feature is that the decentralized controller has equivalency to those designed by backstepping approach. As a complementary support to the design procedure, the sufficient condition of the whole closed-loop system stability is analyzed via the small gain theorem and it can be proven that the process tracking performance is improved. The simulation results of the Shell benchmark control problem are provided to verify the effectiveness and practicality of the proposed decentralized PID control.     

基于卡尔曼滤波的液压主动悬架控制研究

汽车的液压主动悬架系统在控制过程中不可避免的受到噪声的影响。应用卡尔曼滤波对系统的状态向量做最优估计,并应用到系统的全状态反馈控制中,可以有效的提高系统的鲁棒性。文章给出了卡尔曼滤波的应用条件,对单一LQR调节器系统和基于LQG理论的调节器系统做了仿真对比。在LQR调节器系统中前置卡尔曼滤波,能得到更好的振动控制效果。     

基于Backstepping方法的移动机器人路径跟踪问题研究

针对轮式移动机器人的路径跟踪问题以及其非完整特性,引入一种新的虚拟反馈量,使用反演法设计了路径跟踪控制器.首先通过移动机器人的运动学模型得出其运动学位姿误差微分方程,然后基于Backstepping(逐步后推)方法设计控制器,通过构造的Lyapunov函数证明了所设计的控制器的稳定性;最后用Matlab进行仿真以及SM35机器人进行实验,结果表明,所设计的控制器能使移动机器人以任意小的误差跟踪任意给定的参考路径.     

基于遗传算法的最优控制加权阵的设计

遗传算法作为一种全局优化算法在自动控制领域得到了广泛的应用，在线性二次型最优控制设计中加权阵的选择是一项既重要又困难的工作，提出一种根据系统瞬态响应这一具有直接工程意义的品质指标，通过遗传算法来确定线性二次型最优控制加权阵的设计方法。根据这样确定的加权阵设计的最优控制器可实现闭环系统具有所期望的响应特性，且满足最优性以保证闭环系统的渐近稳定性及具有较大的稳定裕量。通过一个单输入单输出三阶系统的仿真实例说明了此方法的可行性与有效性。     

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.     

Robust impedance control of a hydraulic suspension system

A novel robust impedance control approach is developed to control dynamic behavior of a vehicle subject to road disturbances. This behavior is predetermined as an impedance rule to achieve passenger comfort and vehicle handling by the use of a hydraulically actuated suspension system. Impedance control law is simple, free of model and efficient to apply for a broad range of road conditions. Moreover, it relates comfort to handling. This control approach can provide a desired comfort when passing a bump, and both desired comfort and handling after passing a bump. Robust position and force controls are used to implement the robust impedance control with the presence of uncertainties. A transformed proportional–integral–derivative control is proposed to perform the robust control. The system stability is analyzed and analytical results are confirmed by simulations. A quarter‐car model of suspension system and a nonlinear model of hydraulic actuator are used to simulate the control system. Copyright © 2009 John Wiley & Sons, Ltd.     

非线性主动悬架系统自适应最优控制

针对非线性主动悬架系统多性能指标综合优化问题,提出一类自适应最优控制方法.首先,通过引入一阶低通滤波操作,利用系统输入输出构建结构简单且调节参数少的一类未知非线性动态估计器,在线估计系统未知非线性动态;其次,构建包含乘驾舒适度、悬架行程空间及输入能耗的性能指标函数,采用单层神经网络对最优性能指标函数进行在线逼近,并得到新的哈密尔顿函数;为实现在线求解,构建一类新的基于参数估计误差信息的自适应律,在线更新神经网络权值并计算最优控制律;最后,理论分析闭环系统稳定性和收敛性,并通过专业软件Carsim与Matlab/Simulink搭建的联合仿真平台给出的对比仿真结果,验证所提出方法可有效解决主动悬架系统多目标性能优化控制问题,提升主动悬架系统综合性能.     

半车非线性悬架的非平稳随机振动及控制

研究了1/2车非线性悬架模型在路面随机激励下的非平稳振动响应,并基于随机最优控制理论对其进行主动控制.首先利用等效线性化方法将具有非线性阻尼及迟滞刚度的非线性悬架模型线性化,然后将主动、被动悬架非平稳随机响应进行比较,结果表明非线性主动悬架的性能要优于被动悬架.最后,通过Monte-Carlo数值模拟验证了理论结果.     

Robust passivity-based control design for active nonlinear suspension system

In this article, we propose a novel interconnection and damping assignment passivity-based control (IDA-PBC) design for a quarter car nonlinear active suspension system. As an energy shaping method, IDA-PBC is suitable for applying the main concept of skyhook (SH) control. In addition to the damping term, we utilize the characteristics of the energy shaping method to change the sprung and unsprung masses, thereby strengthening the vibration suppression effect. An IDA-PBC-based controller design for an active suspension system, which includes a nonlinear spring, a nonlinear damper, and mass uncertainty, is proposed. Different from most IDA-PBC applications, which tend to control the position or the velocity, our methods focus on transforming a nonlinear suspension system into a desired linear system with ideal aseismatic properties. Unlike a conventional controller using the SH control strategy, we design a virtual vehicle body and an unsprung mass in addition to the damper coefficients. By deriving the port-Hamiltonian form of the suspension system from its dynamics and rewriting it based on the relative coordinates, we obtain a feedback law that only uses the relative displacement and velocity of the suspension system. We derive the conditions for ensuring the global asymptotical stability of the suspension system and propose the guidelines for parameter selection that can guarantee robust stability against parameter uncertainties.     

基于模糊控制策略的车辆主动悬架研究

建立了车辆整车7自由度模型的主动悬架控制的系统状态方程模型,设计了两种模糊控制策略,方法一针对整车模型,采用一种控制方法,方法二针对整车模型的运动方式,设计不同的模糊控制器,垂直振动模糊控制器,俯仰振动模糊控制器,侧倾振动模糊控制器和逻辑控制器,仿真结果表明,所设计的模糊控制器对提高车辆的舒适性与操纵稳定性有较好的效果.     

Application of LQ-based semi-active suspension control in a vehicle

A linear quadratic (LQ) based controller and observer concept for a semi-active full-car model is implemented and compared to a skyhook controller using a real vehicle in this paper. Especially an observer including a new modified road model is presented, which reliably filters low frequency disturbances induced by ascending or descending steep hills. Furthermore, methods for the parametrization of the quadratic cost function are presented and it is shown in experiments for different vehicle masses that ride comfort and road holding can be significantly improved by using semi-active suspension control. In order to take nonlinear component characteristics or suspension friction into account a parametrized nonlinear full-car model is presented, which is used for the determination of the controller cost function weights. The performance evaluation is done using a 4-poster test rig as well as measurements conducted on a real road.     

Robust active suspension design subject to vehicle inertial parameter variations

This paper presents an approach in designing a robust controller for vehicle suspensions considering changes in vehicle inertial properties. A four-degree-of-freedom half-car model with active suspension is studied in this paper, and three main performance requirements are considered. Among these requirements, the ride comfort performance is optimized by minimizing the H∞ norm of the transfer function from the road disturbance to the sprung mass acceleration, while the road holding performance and the suspension deflection limitation are guaranteed by constraining the generalized H2 (GH2) norms of the transfer functions from the road disturbance to the dynamic tyre load and the suspension deflection to be less than their hard limits, respectively. At the same time, the controller saturation problem is considered by constraining its peak response output to be less than a given limit using the GH2 norm as well. By solving the finite number of linear matrix inequalities (LMIs) with the minimization optimization procedure, the controller gains, which are dependent on the time-varying inertial parameters, can be obtained. Numerical simulations on both frequency and bump responses show that the designed parameter-dependent controller can achieve better active suspension performance compared with the passive suspension in spite of the variations of inertial parameters.     

具有执行器容错的汽车主动悬架系统有限频率H∞控制

本文研究了一类具有执行器容错的主动悬架系统有限频率H_∞控制问题.运用广义的Kalman-Yakubovich-Popov(KYP)引理,设计了有限频率H_∞控制器.该控制器不仅能够最大程度地减少路面在4～8 Hz范围内对乘客的影响,还能够保证汽车的悬架行程和车轮的动静载之比在它们允许的范围内.因此所设计的有限频率H_∞控制器不仅能够保证汽车驾驶的舒适性还能够保证汽车驾驶的安全性.为了解决系统状态不完全可测的问题,本文采用了动态输出反馈控制器策略.除此之外,在控制器的设计过程中还考虑了主动悬架系统的参数不确定性以及执行器随机故障的现象.最后,本文基于四分之一汽车主动悬架系统验证了控制器的有效性.     

Constrained optimal control: an application to semiactive suspension systems

This article applies three different control techniques to the design of a quarter-car semiactive suspension system. The three techniques, originally developed to solve a constrained optimal control problem, are optimal gain switching, discontinuous variable structure control and explicit model predictive control. All of them divide the state space into convex regions and assign a linear or affine state feedback controller to each region. The partition of the state space is computed off-line. During the on-line phase, the controller switches between the subcontrollers according to the current state. All the above techniques gave satisfactory results when applied to the design of semiactive suspension systems. A detailed comparison in terms of computational complexity, performance and simplicity of the design is proposed in the article.