混合动力履带车辆能量分配控制策略研究

在履带车辆能量控制策略的研究中,相比于传统的履带车辆单一的动力源,混合动力履带车辆是多能源动力系统,能量分配控制策略制约着动力系统的运行效率.为了优化能量分配控制以及改善整车的燃油经济性,提出了在发动机多点转速下,采用模糊控制理论的动力系统功率分配控制策略;建立了面向控制的整车动态仿真模型,包括驾驶员模型,动力电池组模型,发动机模型,电机模型以及整车动力学模型.根据建立的车辆动态模型,采用模糊分配控制策略,在不同的SOC初值、不同的循环工况以及不同的控制策略下仿真,结果表明,利用模糊规则的能量分配控制策略燃油经济性较好,并且能保持动力电池组SOC平衡在在一定范围内.     

基于遗传算法的增程式电动车模糊控制器设计

针对燃料电池增程式电动汽车动力系统双能量源间的分配问题,设计基于遗传算法的多输入单输出(MISO)模糊控制器。控制器将动力蓄电池SOC和负载总线实时需求功率作为输入变量,求解燃料电池增程器的最佳输出功率,从而获得蓄电池和燃料电池的输出功率分配关系,以此实现不同功率需求下车载多能量源间的合理分配。为克服传统模糊控制器的参数设置仅依靠专家经验设定的局限性,采用遗传算法对模糊控制器的隶属函数和控制规则参数进行优化设计。通过ADVISOR软件仿真和转鼓实验台实车验证,结果证明,与传统能量控制策略相比,优化设计后的模糊控制能量管理策略能够明显提高增程式电动汽车的燃料经济性,并表现出较好的工况适应能力。     

ISG-FHEV等效燃油消耗最小控制策略

为了有效提高ISG重度混合动力汽车(full hybrid electric vehicle assisted by an integrated starter generator,ISG-FHEV)发动机和电机驱动系统效率以及整车的燃油经济性,设计了一种等效燃油消耗最小控制策略(equivalent consumption minimization strategy,ECMS);在分析ISG-FHEV功率分流模式的基础上,同时考虑发动机和电机驱动系统效率,构建出包含发动机和电机驱动系统的功率分配、ISG电机和主电机间的功率分配两个控制变量的整车等效燃油消耗最小目标函数;引入庞特里亚金极小值原理(pontryagin’s minimum principle,PMP)并加入电池SOC偏差控制确定等效因子;最后,进行了仿真和对比分析;结果表明,与基于规则的控制策略相比,发动机效率提高9%,ISG电机和主电机总效率提高11.4%,百公里耗油量降低9.98%。     

并联新能源汽车最优效率实时控制

为了提高并联混合动力汽车驱动系统的实时效率,降低燃油消耗,本文提出一种基于效率最优的协调控制策略.根据不同驱动模式下电池的充放电状态,建立了充放电状态下驱动系统的等效燃油消耗模型,在分析电池效率和发动机效率的基础上,得到驱动系统效率的统一表达式,进而通过建立不同功率需求不同荷电状态下系统最优效率的功率分配系数图谱,设计了系统效率最优的协调控制策略,协调控制策略根据优化的功率分配系数在发动机和电机间进行力矩分配,协调控制策略可以离线计算并实时执行.两种工况循环下的仿真结果表明效率最优控制策略能有效地提高混合动力系统实时效率和燃油经济性.     

电动汽车用飞轮电池充放电控制系统研究

针对现有电池技术还不能满足电动汽车对电池系统能量密度和功率密度还有寿命的要求,本文结合蓄电池的高比能量和飞轮电池的高比功率,提出了基于蓄电池和飞轮电池的复合电源。建立了飞轮电池的充放电的数学模型,并提出了飞轮电池充放电的控制策略。飞轮充电过程中采用模糊-PI复合控制策略,放电过程中根据驱动电机需要的瞬时电流值来控制斩波器开关的通断。结果表明系统具有较好的动态特性。     

神经网络工况识别的混合动力电动汽车模糊控制策略

采用模糊控制可以改进混合动力电动汽车(HEV)的燃油经济性和排放性,但是对模糊控制器进行优化时通常只针对某一典型工况.不同的城市的行驶工况有一定差别,影响了模糊控制改善混合动力电动汽车性能的效果.研究中以广州和上海市主干道行驶工况为例,首先建立了一个模糊控制策略,并采用遗传算法,以汽车燃油经济性和排放性为优化目标,分别针对广州和上海主干道行驶工况对模糊控制器中隶属度函数进行优化.然后建立了一个基于模糊神经网络的行驶工况识别方法,通过识别广州和上海的主干道行驶工况,对控制策略中模糊控制器的隶属度参数进行相应调整,结果证明采用模糊神经网络识别行驶工况的HEV模糊控制策略可以进一步提高汽车的燃油经济性和排放性能.     

多能源电动汽车中的Fuzzy控制策略及仿真

多能源电动汽车的能量存储系统由锌空电池、镍氢电池和超大电容三种能量存储元件组成。锌空电池为负载提供基本能量。镍氢电池工作在中级能量区，并回收下坡和刹车过程中的能量。超大电容工作在尖峰负载区，为大加速度过程提供能量，在短时间内可以实现能量回收。该文在多能源电动汽车的模型基础上，针对能量管理系统(EMS)提出了一种模糊控制策略。EMS模糊控制策略的输入包括所需功率、镍氢电池的SOC和超大电容的SOC，模糊控制策略的输出包括三个能量存储元件的分配功率因子，每个输入和输出有不同的模糊量。仿真结果表明：模糊控制策略比简单查表控制策略在续驶里程、燃料经济性和效率等方面均有所改善。     

并联式混合动力汽车双模糊控制能量管理策略研究

针对单模糊控制策略下再生制动能量不能得到充分回收,提出了一种并联式混合动力汽车的双模糊控制能量管理策略.分别设计了驱动和制动工况下相应的模糊控制器,简化了控制系统设计的复杂度.最后,在Matlab中利用Advisor软件对所设计的双模糊控制策略进行了仿真.结果表明,与电辅助控制策略和单模糊控制策略相比,所设计的双模糊控制能量管理策略,在有效提高燃油经济性和制动工作效率的同时,极大地降低了废气排放.     

光储系统直流母线电压与超级电容荷电管理控制

光储并网系统中, 针对电压源型换流器(VSC)中外环直流母线电压无静差控制, 提出改进型PI控制方法.根据超级电容荷电状态(SOCsc)提出基于交互控制及限值管理混合储能系统二次功率分配控制策略. 临界充放电模式下, 引入虚拟修正电流的概念, 根据超级电容分配功率的正负及交互速率因子确定虚拟修正电流的大小, 使SOCsc向稳定的区间变化; 极限充放电模式下, 对SOCsc进行限制管理, 避免其过充过放现象. 通过算例分析, 验证了所提改进型PI控制策略的优越性; 并基于获得的SOCsc进行二次功率分配, 控制其荷电状态(SOC)运行于相对稳定工作区间.     

基于粒子群优化的并联式混合动力汽车模糊能量管理策略研究

针对一种并联式混合动力轿车,以混合驱动系统需求转矩和电池组荷电状态(SOC)为输入,以发动机转矩为输出,构建了能量管理模糊控制器,并以总的等效燃油消耗为优化目标,利用粒子群算法对模糊隶属度函数参数和模糊控制规则进行优化.基于ADVISOR的仿真研究表明,与未优化的模糊能量管理策略相比,经过优化的模糊能量管理策略能够更有效地降低混合动力汽车的燃油消耗,更好地控制电池组SOC的变化.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.