关联时滞大系统的保性能控制

针对关联项具有N×N个任意未知常时滞的线性连续大系统,采用线性矩阵不等式(LMIs)方法,提出了一种分散的无记忆状态反馈二次保性能控制器的存在条件和设计方法.最后用一个示例说明分散无记忆状态反馈二次保性能控制器的设计方法.     

Roll- and pitch-plane coupled hydro-pneumatic suspension

Passive fluidically coupled suspensions have been considered to offer a promising alternative solution to the challenging design of a vehicle suspension system. A theoretical foundation, however, has not been established for fluidically coupled suspension to facilitate its broad applications to various vehicles. The first part of this study investigates the fundamental issues related to feasibility and properties of the passive, full-vehicle interconnected, hydro-pneumatic suspension configurations using both analytical and simulation techniques. Layouts of various interconnected suspension configurations are illustrated based on two novel hydro-pneumatic suspension strut designs, both of which provide a compact design with a considerably large effective working area. A simplified measure, vehicle property index, is proposed to permit a preliminary evaluation of different interconnected suspension configurations using qualitative scaling of the bounce-, roll-, pitch- and warp-mode stiffness properties. Analytical formulations for the properties of unconnected and three selected X-coupled suspension configurations are derived, and simulation results are obtained to illustrate their relative stiffness and damping properties in the bounce, roll, pitch and warp modes. The superior design flexibility feature of the interconnected hydro-pneumatic suspension is also discussed through sensitivity analysis of a design parameter, namely the annular piston area of the strut. The results demonstrate that a full-vehicle interconnected hydro-pneumatic suspension could provide enhanced roll- and pitch-mode stiffness and damping, while retaining the soft bounce- and warp-mode properties. Such an interconnected suspension thus offers considerable potential in realising enhanced decoupling among the different suspension modes.     

Roll- and pitch-plane-coupled hydro-pneumatic suspension. Part 2: dynamic response analyses

In the first part of this study, the potential performance benefits of fluidically coupled passive suspensions were demonstrated through analyses of suspension properties, design flexibility and feasibility. In this second part of the study, the dynamic responses of a vehicle equipped with different configurations of fluidically coupled hydro-pneumatic suspension systems are investigated for more comprehensive assessments of the coupled suspension concepts. A generalised 14 degree-of-freedom nonlinear vehicle model is developed and validated to evaluate vehicle ride and handling dynamic responses and suspension anti-roll and anti-pitch characteristics under various road excitations and steering/braking manoeuvres. The dynamic responses of the vehicle model with the coupled suspension are compared with those of the unconnected suspensions to demonstrate the performance potential of the fluidic couplings. The dynamic responses together with the suspension properties suggest that the full-vehicle-coupled hydro-pneumatic suspension could offer considerable potential in realising enhanced ride and handling performance, as well as improved anti-roll and anti-pitch properties in a very flexible and energy-saving manner.     

关联时滞大系统的保性能控制

针对关联项具有N×N个任意未知常时滞的线性连续大系统,采用线性矩阵不等式(LM Is)方法,提出了一种分散的无记忆状态反馈二次保性能控制器的存在条件和设计方法.最后用一个示例说明分散无记忆状态反馈二次保性能控制器的设计方法.     

四级阻尼可调式液压互联悬架系统性能研究

提出了一种新型四级阻尼可调式液压互联悬架 （FDAHIS） 系统。FDAHIS系统在被动液压互联悬架系统的阻尼阀上并联了两个常通孔面积不同的电磁开关阀,通过反馈控制策略控制电磁阀开闭状态,调节系统液压流量,从而实现阻尼四级可调。为了研究该系统性能,建立FDAHIS系统模型和七自由度整车模型。通过系统单元台架试验对该模型进行了验证。整车仿真结果表明,与被动的液压互联悬架 （HIS） 系统相比,FDAHIS系统在车辆行驶平顺性和抗俯仰性能方面表现更佳。     

交叉互连油气弹簧抗侧倾特性研究及试验

针对多轴重型特种车辆存在的偏载问题,为了减小偏载对静态姿态以及转弯行驶稳定性的不良影响,设计一种交叉互连油气弹簧.从液压原理方面分析了交叉互连油气弹簧的抗侧倾作用,通过悬架侧倾角刚度推导和仿真,验证了交叉互连油气弹簧具有良好的抗侧倾特性.将油气弹簧进行装车试验,通过静载工况、转弯工况的实车试验,进一步验证了交叉互连油气...     

我国高速铁路运营调度系统设计与实现

本文在分析我国高速铁路运营调度系统设计与实现的基础上,从整体性方面总结运营调度系统特点,并对高速铁路运营调度系统发展关注的问题进行了分析和阐述.     

考虑气液混合流体时变特性的阀片式液压互联悬架建模

针对液压互联悬架中气液混合流体对悬架系统特性的影响,推导了气液混合流体物理性质的时变特性模型,提出一种非线性形变修正函数,用以修正所建立的阻尼阀阀片变形等效模型,从而建立了一种考虑气液混合流体时变特性的阀片式单缸液压互联悬架非线性动力学模型,并通过台架试验加以验证.仿真结果表明:气液混合流体时变特性会导致液压互联悬架系...     

用LMI方法设计不确定关联时滞大系统H∞容错控制器

针对关联项具有N×N个任意未知常时滞的不确定线性连续大系统,在执行器失效的情况下,提出了一种分散的鲁棒H∞容错控制器的设计方法,通过假设可能失效执行器的输出信号为能量有界的干扰输入信号,不确定关联时滞大系统的容错控制问题转化为分散的鲁棒H∞控制问题.控制器可以通过解线性矩阵不等式给出,因而具有数值易解性.最后用一个数值例子验证了该设计方法的有效性.     

Switched control of vehicle suspension based on motion-mode detection

This paper presents a study on switched control of vehicle suspension based on motion-mode detection. This control strategy can be potentially implemented via the interconnected suspension such as hydraulically interconnected suspension by actively switching its interconnection configuration in terms of the dominant vehicle body motion-mode. The design of the switched control law is developed focusing on three vehicle body motion-modes: bounce, pitch, and roll. At first, an H_∞ optimal controller will be designed for each motion-mode with the use of a common quadratic Lyapunov function, which guarantees the stability of the switched system under arbitrary switching functions. Then, a motion-mode detection method based on the calculation of the motion-mode energy is introduced. And then, the possible implementation of the control system in practice is discussed. Finally, numerical simulations are used to validate the proposed study.