基于Matlab的颤振自激力时域化

基于风洞试验得到的颤振导数无法直接应用于颤振时域计算,需要基于最小二乘原理拟合得到颤振自激力的时域表达式,方能进行时域计算。基于Matlab提供的lsqnonlin函数,对颤振自激力的时域化表达式中的未知系数进行拟合,并得到了较好的结果。     

电力电子变压器多指标非线性控制研究

电力电子变压器是一种通过电力电子变换实现电力系统能量传递的新型变压器.以微分几何理论为基础,实现非线性系统的多性能指标控制,提出基于跟踪偏差的非线性控制器,以实现改善电力系统控制性能的目的,从而可在统一的非线性控制设计框架下同时对系统中多个状态量的性能指标提出要求.所提控制策略解决了系统的非线性问题,改善了系统的动态性能,仿真结果表明设计的控制方法在电力电子变压器输出稳定性控制.     

非线性滤波器在动力定位船位估计中的应用

针对动力定位船舶在作业过程中因丢失GPS位置测量信号,从而导致动力定位系统不能正常工作,而使船舶偏离作业点的问题,设计了一种非线性滤波器,它可以利用以前保存的历史数据进行船舶位置的实时估计,从而使船舶在一定的时间内可以维持在作业点附近,当重新获得GPS信号后,又可以快速地进入正常工作状态。为了使历史数据能够更准确地反映船舶的实时位置,利用历史数据相对于作业点的平均偏差对历史数据进行了补偿。最后给出了此非线性滤波器在船舶仿真系统中的仿真曲线,分析表明在有滤波器的情况下,船舶真实位置估计的准确度比没有滤波器的情况下有明显的改善。     

最小实体要求(LMR)及其应用

本文简要介绍了 LMR的基本内容 ,通过实例说明其在设计中的应用 ,并对相应工艺提出建议     

Multivariable speed synchronisation for a parallel hybrid electric vehicle drivetrain

In this article, a new drivetrain configuration of a parallel hybrid electric vehicle is considered and a novel model-based control design strategy is given. In particular, the control design covers the speed synchronisation task during a restart of the internal combustion engine. The proposed multivariable synchronisation strategy is based on feedforward and decoupled feedback controllers. The performance and the robustness properties of the closed-loop system are illustrated by nonlinear simulation results.     

High-speed train control based on multiple-model adaptive control with second-level adaptation

Speed uplift has become the leading trend for the development of current railway traffic. Ideally, under the high-speed transportation infrastructure, trains run at specified positions with designated speeds at appointed times. In view of the faster adaptation ability of multiple-model adaptive control with second-level adaptation (MMAC-SLA), we propose one type of MMAC-SLA for a class of nonlinear systems such as cascaded vehicles. By using an input decomposition technique, the corresponding stability proof is solved for the proposed MMAC-SLA, which synthesises the control signals from the weighted multiple models. The control strategy is utilised to challenge the position and speed tracking of high-speed trains with uncertain parameters. The simulation results demonstrate that the proposed MMAC-SLA can achieve small tracking errors with moderate in-train forces incurred under the control of flattening input signals with practical enforceability. This study also provides a new idea for the control of in-train forces by tracking the positions and speeds of cars while considering power constraints.     

大型集装箱船船舶尺度的一种确定方法

随着船舶向大型化发展,现有的船舶主尺度之间关系数学模型已不能满足大型船舶的要求,文中依据多艘实船数据,利用曲线拟合的方法建立大型集装箱船船舶主尺度之间关系的数学模型.     

Connected cruise control: modelling,delay effects,and nonlinear behaviour

Connected vehicle systems (CVS) are considered in this paper where vehicles exchange information using wireless vehicle-to-vehicle (V2V) communication. The concept of connected cruise control (CCC) is established that allows control design at the level of individual vehicles while exploiting V2V connectivity. Due to its high level of modularity the proposed design can be applied to large heterogeneous traffic systems. The dynamics of a simple CVS is analysed in detail while taking into account nonlinearities in the vehicle dynamics as well as in the controller. Time delays that arise due to intermittencies and packet drops in the communication channels are also incorporated. The results are summarised using stability charts which allow one to select control gains to maintain stability and ensure disturbance attenuation when the delay is below a critical value.     

基于超高速AD9954的多模式信号的实现

通过对AD9954采用先进DDS技术性能特点的具体分析，利用其可编程幅度、频率、相位给出AD9954在高速调制信号系统中的应用方案，从而较方便容易地实现基于软件无线电技术的各种调制信号。