现代控制理论与交流电机调速(Ⅵ)--非线性解耦控制

提出一种基于微分几何的精确反馈线性化控制方法,介绍其基本概念及在交流电机调速系统中的应用原理.分析了磁场定向控制的局限性,即它只能获得渐近的输入-输出线性化和解耦.而采用基于微分几何的精确反馈线性化方法,即使在磁场变化的情况下系统暂态响应也是解耦的,这有利于改善交流电机这类具有非线性特征的电气传动系统的性能.     

有反馈和N-策略多重休假的M^X／（G，Gm）／1排队模型

研究N-策略多重休假下，顾客是批量到达的M^x（G，Gm）／1排队模型。一旦系统空闲服务台就开始一个随机长度的休假，休假结束后，如果发现顾客数达到或超过N，就立即对顾客进行服务直到系统空闲，如果发现顾客数小于N，就进行下一阶段随机长度休假。服务台提供两阶段服务：第一阶段初步服务和第二阶段m种选择服务。在第一阶段初步服务结束后，顾客可以回到队列要求重新服务，也可以立即离开系统，或接受第二阶段m种选择服务中某一种服务。通过补充变量法得到了稳态下系统队长的概率母函数和其随机分解性质。进一步计算出系统稳态的队长及其他性能指标。     

试论铁路运输安全管理

安全管理工作中应用科学管理方式的必要性,当前铁路运输安全管理方中的不足,高速发展的铁路客货运输应采用的科学管理方式。     

射频功放的非线性分析与线性化技术

分析了射频功率放大器的非线性特性，对常见的功率放火器线性化技术的原理和实现方法进行了系统的分析，比较了它们的优缺点，为选择射频功率放大器的线性化技术提供了重要的参考。     

Low-power and Low-cost Design of Survival Memory Unit for 1000Base-T Gigabit Ethernet Transceiver

Introduction The Gigabit Ethernet (GbE) on category-5unshielded twins pair (UTP) which corresponds tothe IEEE 802.3 ab1000 Base-T standard has grad-ually become the main trend of local area network(LAN). To take advantage of the additional cod-ing gain offered by the trellis-coded modulation(TCM) coding without using a maximum likeli-hood sequence estimation (MLSE) decoder, a deci-sion feedback sequence estimate[1](DFSE) decodercan be used[2-6]. Like the decision feedback equalizer …     

Disturbance compensation with a torque controllable steering system

Via a conventional steering system the driver perceives desired and disturbing effects such as road feedback and resonance effects, respectively. They appear with overlapping frequency spectra within the driver's steering torque. This paper introduces a control algorithm that is suppressing periodic disturbances without affecting useful steering road feedback attributes as well as regular power assistance characteristic. This is realised by an integrated torque actuator within the steering column in conjunction with a conventional Hydraulic-assisted Power Steering (HPS) system.     

EMS型磁浮列车模块的运动耦合研究

EMS型低速磁浮列车通常采用模块化的转向架结构,模块是集悬浮、导向和牵引功能于一身的基本功能单元.模块内部的2个悬浮端通过刚体连接,导致两端的运动状态互相耦合.常用的处理方法是将这种耦合作为系统的外部干扰,通过提高系统的鲁棒性加以抑制.本文从机械运动的角度,研究了EMS型低速磁浮列车模块的耦合问题,提出通过解耦算法实现2个悬浮端之间的运动解耦.首先在对物理模型进行合理简化和假设的基础上,建立了模块悬浮系统的数学模型,并以此为基础分析了模块运动耦合的本质,然后提出了通过反馈线性化方法实现模块运动电气解耦的方案.仿真结果表明,模块的运动耦合对悬浮系统动态特性具有显著的影响,本文提出的解耦方案可有效地解决耦合问题,简化悬浮控制器的设计,提高悬浮系统的性能.     

ROBUST CONTROL WITH COVARIANCE CONSTRAINT FOR UNCERTAIN SAMPLED-DATA FEEDBACK CONTROL SYSTEMS

ＩｎｔｒｏｄｕｃｔｉｏｎＡｓａｔｉｓｆａｃｔｏｒｙｅｎｇｉｎｅｅｒｉｎｇｃｏｎｔｒｏｌｓｙｓｔｅｍｓｈｏｕｌｄｐｏｓｓｅｓｓｍｕｌｔｉｐｌｅｄｅｓｉｒｅｄｐｅｒｆｏｒｍａｎｃｅｓｓｕｃｈａｓｇｏｏｄｒｏｂｕｓｔｎｅｓｓｔｏｍｏｄｅｌｉｎｇｅｒｒｏｒ．...     

Dynamics of connected vehicle systems with delayed acceleration feedback

In this paper, acceleration-based connected cruise control (CCC) is proposed to increase roadway traffic mobility. CCC is designed to be able to use acceleration signals received from multiple vehicles ahead through wireless vehicle-to-vehicle (V2V) communication. We consider various connectivity structures in heterogeneous platoons comprised of human-driven and CCC vehicles. We show that inserting a few CCC vehicles with appropriately designed gains and delays into the flow, one can stabilize otherwise string unstable vehicle platoons. Exploiting the flexibility of ad-hoc connectivity, CCC can be applied in a large variety of traffic scenarios. Moreover, using acceleration feedback in a selective manner, CCC provides robust performance and remains scalable for large systems of connected vehicles. Our conclusions are verified by simulations at the nonlinear level.     

Can feedback from in-vehicle data recorders improve driver behavior and reduce fuel consumption?

This paper evaluates the effectiveness of feedback, based on In-Vehicle Data Recorders (IVDR), to improve driving behavior, increase driving safety, and reduce fuel consumption. We developed a framework for driving-behavior measurement, incorporating second-by-second data collected by IVDRs. IVDR units were installed in over 150 vehicles driven by more than 350 drivers for over a year. The experiment was divided into three stages. The first stage was a “blind”, control stage, with no feedback. The second stage incorporated verbal feedback given only to riskiest drivers. In the third stage all drivers received a bi-weekly written report about their driving performance. Safety events, such as braking, lateral acceleration or speeding, were recorded. Supplementary data regarding safety related events and fuel consumption were also collected. Safety incidents and fuel consumption were modeled as a function of IVDR measurement-based events, in order to identify which events best reflect safety incidents and excessive fuel consumption. Our results show that braking events best explain safety incidents, and all events together best explain fuel consumption. In addition, we found that for the riskiest drivers, feedback significantly reduced the IVDR events. Our models show that feedback can lead to a reduction of 8% in safety incidents, and 3–10% in fuel consumption, with a larger reduction obtained for large vehicles.