引入迭代阈值判决导引判决反馈盲均衡算法

基于判决圆的常数模算法(CMA)和判决导引算法(DD)相结合的判决反馈盲均衡算法(CMA+DD),在均衡的起始阶段,由于眼图未睁开,DD算法无法收敛,导致收敛速度慢.为了加快收敛速度,在迭代过程中引入迭代阈值limit,以修改CMA+DD算法的判决条件,从而得到改进的CMA+DD算法(MCMA+DD).该算法在均衡的起始阶段先采用CMA迭代limit次,然后再根据判决圆进行切换.水声信道仿真结果表明,MCMA+DD算法收敛速度快;迭代阈值不同,影响收敛速度;仍具有冷启动和重新启动能力.     

基于变频技术的闭环汽车传动系统试验台的研究

介绍了采用变频技术的汽车传动系统试验台系统结构和原理，阐述了变频器在汽车传动系统总成部件测试中的运用。通过变频器的组合使用，使驱动电机和负载电机实现电闭环。以自动变速器测试为实例．试验台能按照测试要求加载，并且能够进行能量反馈和再利用。     

基于可拓切换控制方法的智能车辆车道保持系统研究（双语出版）

针对道路曲率变化范围较大时，智能车辆在大曲率道路工况车道保持控制精度低的问题，提出一种基于可拓切换控制理论的智能车辆车道保持控制系统，该车道保持系统由上层可拓控制器和下层控制器两部分组成。在上层可拓控制器中，通过车道线检测得到车辆相对于道路的位置信息和道路曲率信息。根据可拓集合理论，选取预瞄点处横向位置偏差和前方道路曲率值作为可拓集合的特征值并划分可拓集合，求解关联函数，并根据关联函数值将车辆-道路系统状态分为经典域、可拓域和非域。在下层控制器中，在经典域采用基于横向位置偏差和航向偏差的PID反馈控制器，在可拓域中采用基于前方道路曲率的PID前馈-反馈控制器，非域中车辆-道路系统处于完全失控状态，采取紧急制动。2种仿真工况结果表明：相比于单一PID反馈控制，提出的车道保持控制系统，有效抑制了在大曲率道路下的跟踪误差值，提高了智能驾驶汽车在时变曲率的道路工况下车道保持控制精度和工况适应性。     

基于高频PWM整流逆变技术的能量回馈装置研究

结合高频PWM整流逆变电路高功率因数、低谐波特性,提出了一种可实现再生能量回馈利用的装置。文中介绍了该装置的主电路拓扑结构和工作原理,并根据它的等效电路和功率平衡关系建立了数学模型。从实现单位功率因数有源逆变控制出发,设计了双闭环直接电流控制系统,利用Ziegler-Nichols整定算法得到内外环PI调节器的参数。通过Matlab/Simulink仿真表明,方案设计合理,控制系统有良好的动静态性能。     

Nonlinear feedforward–feedback control of clutch-to-clutch shift technique

To improve the shift quality of the vehicle with clutch-to-clutch gear shifts, a nonlinear feedforward–feedback control scheme is proposed for clutch slip control during the shift inertia phase. The feedforward control is designed based on flatness in consideration of the system nonlinearities, and the linear feedback control is given to accommodate the model errors and the disturbances. Lookup tables, which are widely used to represent complex nonlinear characteristics of powertrain systems, appear in their original form in the designed feedforward controller, while the linear feedback controller is calculated through linear matrix inequalities such that the control system is robust against the parameter uncertainties. Finally, the designed controller is tested on an AMESim powertrain simulation model, which contains a time-variant model of clutch actuators.     

Fault-tolerant control of heavy-haul trains

The fault-tolerant control (FTC) of heavy-haul trains is discussed on the basis of the speed regulation proposed in previous works. The fault modes of trains are assumed and the corresponding fault detection and isolation (FDI) are studied. The FDI of sensor faults is based on a geometric approach for residual generators. The FDI of a braking system is based on the observation of the steady-state speed. From the difference of the steady-state speeds between the fault system and the faultless system, one can get fault information. Simulation tests were conducted on the suitability of the FDIs and the redesigned speed regulators. It is shown that the proposed FTC does not explicitly worsen the performance of the speed regulator in the case of a faultless system, while it obviously improves the performance of the speed regulator in the case of a faulty system.     

基于反馈线性化的船舶自动舵动态滑模控制

针对船舶自动舵的航向控制问题,结合高阶滑模和动态滑模控制的设计思想设计了一种船舶自动舵动态滑模控制器.首先设计出包含舵机特性的船舶航向控制仿射非线性系统模型,其次通过状态反馈的方法将原模型变为等价的完全可控型线性化系统,然后设计出动态滑模控制器.仿真结果表明,所设计的动态滑模控制器不仅能很好的自动跟踪设定的航向,而且能有效的抑制系统的抖振现象,达到设计目的,为研究船舶自动舵控制提供一种参考.     

Coupled vibration analysis of Maglev vehicle-guideway while standing still or moving at low speeds

Dynamic instability, that is, resonance, may occur on an electromagnetic suspension-type Maglev that runs over the elevated guideway, particularly at very low speeds, due to the flexibility of the guideway. An analysis of the dynamic interaction between the vehicle and guideway is required at the design stage to investigate such instability, setting slender guideway in design direction for reducing construction costs. In addition, it is essential to design an effective control algorithm to solve the problem of instability. In this article, a more detailed model for the dynamic interaction of vehicle/guideway is proposed. The proposed model incorporates a 3D full vehicle model based on virtual prototyping, flexible guideway by a modal superposition method and levitation electromagnets including feedback controller into an integrated model. By applying the proposed model to an urban Maglev vehicle newly developed for commercial application, an analysis of the instability phenomenon and an investigation of air gap control performance are carried out through a simulation.     

Non-fragile multi-objective static output feedback control of vehicle active suspension with time-delay

This paper presents an approach to design a delay-dependent non-fragile H_∞/L₂–L_∞ static output feedback (SOF) controller for active suspension with input time-delay. The control problem of quarter-car active suspension with actuator time-delay is formulated to a H_∞/L₂–L_∞ control problem. By employing a delay-dependent Lyapunov function, new existence conditions of delay-dependent non-fragile SOF H_∞ controller and L₂–L_∞ controller are derived, respectively, in terms of the feasibility of bilinear matrix inequalities (BMIs). Then, a procedure based on linear matrix inequality optimisation and a hybrid algorithm of the particle swarm optimisation and differential evolution is used to solve an optimisation problem with BMI constraints. Design and simulation results of non-fragile H_∞/L₂–L_∞ controller for active suspension show that the designed controller not only can achieve the optimal performance and stability of the closed-loop system in spite of the existence of the actuator time-delay, but also has significantly improved the non-fragility characteristics over controller perturbations.     

基于MATLAB/SIMULINK的异步牵引电机反馈试验方案仿真

文章介绍了一种新的异步牵引电机反馈试验方案,并用MATLAB/SIMULINK对该方案进行一定的建模与仿真,并给出仿真的方法和结果。