Pole location control design of an active suspension system with uncertain parameters

This paper addresses the problem of robust control design for an active suspension quarter-car model by means of state feedback gains. Specifically, the design of controllers that assure robust pole location of the closed-loop system inside a circular region on the left-hand side of complex plane is investigated. Three sufficient conditions for the existence of a robust stabilizing state feedback gain are presented as linear matrix inequalities: (i) the quadratic stability based gain; (ii) a recently published condition that uses an augmented space and has been here modified to cope with the pole location specification; (iii) a condition that uses an extended number of equations and yields a parameter-dependent state feedback gain. Unlike other parameter-dependent strategies, neither extensive gridding nor approximations are needed. In the suspension model, the sprung mass, the damper coefficient and the spring constant are considered as uncertain parameters belonging to a known interval (polytope type uncertainty). It is shown that the parameter-dependent gain proposed allows one to impose the closed-loop system pole locations that in some situations cannot be obtained with constant feedback gains.     

Development of a systematic and practical methodology for the design of vehicles semi-active suspension control system

In this paper, a novel systematic and practical methodology is presented for design of vehicle semi-active suspension systems. Typically, the semi-active control strategies developed to improve vehicle ride comfort and stability have a switching nature. This makes the design of the controlled suspension systems difficult and highly dependent on an extensive trial-and-error process. The proposed methodology maps the discontinuous control system model to a continuous linear region, where all the time and frequency design techniques, established in the conventional control system theory, can be applied. If the semi-active control system is designed to satisfy some ride and stability requirements, an inverse mapping offers the ultimate control law. At the end, the entire design procedure is summarised in six steps. The effectiveness of the proposed methodology in the design of a semi-active suspension system for a Cadillac SRX 2005 is demonstrated with road tests results. Real-time experiments confirm that the use of the newly developed systematic design method reduces the required time and effort in real industrial problems.     

基于HyperWorks导向臂支架的结构优化及改进设计

针对某6×4牵引车复合空气悬架导向臂支架断裂原因进行了分析,排除导向臂支架的铸造缺陷、材料及工艺加工导致失效问题,最终确定导向臂支架的断裂原因主要是由于结构设计不合理导致断裂,在原结构的基础上,确保安装结构基本不变,运用catia三维建模和HyperWorks软件分别完成三种方案的三维建模和静强度分析,通过分析结果比对,改进方案相比原方案,重量降低了8%,疲劳寿命提高了13%,最后经过疲劳寿命分析和15000km的道路可靠性试验,改进后的导向臂支架满足设计使用要求,提高了经济效益。     

接触网刚性悬挂施工工艺

接触网刚性悬挂广泛应用于城市地铁及电气化铁路隧道中，具有载流量大、安全可靠及维修工作量小等特点。笔者根据焦柳铁路石怀线刚性悬挂施工经验，按施工测量、隧道内打孔灌注、支持装置安装调试、汇流排安装、汇流排接触导线架设及膨胀接头安装等6个方面，详细介绍刚性悬挂的施工工艺。     

混合梁自锚式悬索桥钢混接合段结构形式的对比试验研究

广东佛山平胜大桥为我国首座混合梁自锚式悬索桥,钢混接合段是该桥设计的关键技术之一。为确保该桥钢混接合段连接的安全可靠,设计了3种不同结构形式的接合段接头模型,对3种接头模型进行了空间有限元分析和对比模型试验。结果表明:钢混接合段刚度的匀顺过渡可减小应力集中,使传力顺畅;平胜桥钢混接合段设计中对接合面处钢箱梁段作局部加强,对混凝土梁段设置刚度过渡,即采用与本文模型3类似的结构形式比较合理,接合段有足够的承载力;平胜桥钢混接合段采用PBL键连接或采用栓钉连接都是可行的。     

Dynamic simulations of the freight three-piece bogie motion in curve

A loaded freight vehicle with two three-piece bogies is modelled using the accessible mathematical software MATLAB. The results are compared with its corresponding ADAMS/Rail dynamic multibody simulation model, where similar derailment factors are encountered for the freight vehicle. Both models reveal that the possibility of derailment increases immediately after entering and at the end of the curve – signifying the beginning and the end of the curve as two major points for derailment. Although a three-piece bogie construction is rather simple, its mathematical model proves to be very complex and is nonlinear due to the reported frictional contact at the rail/wheel interface as well as the friction wedges. This research is stimulated by bogie derailments that have occurred in the Iranian railways as well as those in the rest of the world.     

万能材料试验机测试轨下橡胶垫板静刚度准确性的措施

结合新型轨下胶垫性能检测项目，对某种万能材料试验机测试轨下橡胶垫板静刚度的原理及存在的问题进行了阐述，并针对存在的问题进行了现场试验，分析了产生问题的原因，并提出采用万能材料试验机测试轨下橡胶垫板静刚度准确性的措施。     

A new method of identification of equivalent suspension and damping rates of full-vehicle model

ABSTRACT

The equivalent spring and damper are often used to simplify the dynamic analysis of a nonlinear full-vehicle model. Clearly, those rates are strongly influenced by the kinematics of a suspension mechanism. This paper presents a new approach to the identification of the equivalent suspension and damping rates. The suspension is considered as a 1-degree-of-freedom (DOF) spatial parallel mechanism. The instantaneous kinestatic relations of the 1-DOF spatial parallel mechanism can be described using the theory of screws. The process of identification of the rates involves three steps: first, the joint positions of the suspension are found from the displacement analysis of the suspension mechanism. Second, the motion of each wheel of four suspension mechanisms is represented by the corresponding instantaneous screw at any instant. Third, the equivalent suspension and damping rates are determined from the kinestatic relations of the instantaneous screw. These rates are used for the dynamic analysis of the nonlinear full-vehicle model consisting of two pairs of the front (double-wishbone) and rear (multi-link) suspensions. Two dynamic behaviours of a car are analysed and compared with the simulation utilising the Adams/View software.     

铁道车辆垂向主动悬挂的预见控制

以4轴客车为研究对象,建立4轴客车车辆的6自由度垂向主动悬挂的动力学模型。主动悬挂的常规控制策略往往对系统本身因素所引起的响应滞后问题表现出无所适从,因此,借助测定的未来目标信号或外扰,对主动悬挂设计一个预见控制器来抑制车辆系统的垂向振动。研究结果表明,采用预见控制策略使车体的垂向振动加速度响应幅值降低60%,转向架的垂向振动加速度响应幅值降低30%左右,同时系统可按设定目标值预见步数为20提前作出响应。     

基于神经网络控制的半主动空气悬架仿真研究

以某空气悬架大客车1/4车辆模型为仿真对象,设计了模型参考神经网络自适应控制器,并以正弦和随机输入为路面激励,以簧载质量垂直方向振动加速度值为控制量,对模型进行了计算机仿真,从簧载质量加速度时间历程可以看出神经网络控制器对工况和结构参数的变化具有较好的自适应能力.