反馈控制系统中调节器的优化设计

本文利用单纯形优化设计方法设计反馈控制系统的调节器.以可控硅双闭环直流宽调速系统为例,提出了优化设计中边长的选择及限幅非线性的处理方法.实例系统优化设计仿真结果与实测性能基本一致,其设计方法适用于带调节器的一般反馈控制系统.     

Modelling the advertising-sales relationship through use of multiple time series techniques

When time series data are available for both advertising and sales, it may be worth while to model the two series jointly. Such an analysis may contribute to our understanding of the dynamic relationships among the series and may improve the accuracy of forecasts. Multiple time series techniques are applied to the well-known Lydia Pinkham data to illustrate their use in modelling the advertising-sales relationship. In analysing the Lydia Pinkham data the need for a joint model is established and a bivariate model is identified, estimated and checked. Its forecasting properties are discussed and compared to other time series approaches.     

河流地貌系统的信息反馈

通过冲积河流系统自动调整现象的分析，对系统自行镇定，自行适应环境的功能特性加深了认识，提出了自然信息是系统各个要素、各个层次、各个部分相互联系、制约的一种耦合基因或制约基因的新观点．系统之所以能够自动地吸收和消除干扰所造成的失谐或突变所引起的偏差，在于系统本身能“理解”如何有目的地行动．这种‘理解”和行动是通过信息反馈完成的．对这种信息及其反馈机制进行深人研究，对于揭示河流系统自组织机理、不同河型的成因，以及对其进行优化与调控，具有重要的意义．     

大容量异步电动机的短路反馈电流

随着电力技术的发展，火电机组的单机容量不断增大，使厂用辅机的异步电动机容量随之增大，大容量异步电动机与小容量异步电动机相比，它们的Ｒ、Ｘ，Ｔ等参数都有较大的差异，而且这种差异随着容量的增大而愈显著，使其供给的短路电流初值的大小和暂态过程中的变化规律都不同。本文对大、小容量异步电动机短路反馈电流的特点作了详细比较，并对大容量异步电动机的短路电流计算作了全面阐述。     

不可测输入的一种观测方法

本文讨论了用状态观测器观测不可测输入变量的问题,运用多项式近似作为不可测输入的动态数学模型,给出这种不可测输入观测器的存在条件和一种简易判别方法,讨论了多项式项数对观测结果的影响。文章还给出了催化剂循环量实时观测的应用实例。     

PWM变频器供电交流调速系统回馈制动的控制方案

对ＰＷＭ变频器供电交流调速系统的回馈制动过程进行了仿真研究,并给出了在制动转矩受约束的条件下实现快速制动的闭环控制方案     

具有反馈控制的广义Logistic模型的Hopf分支

利用特征值理论和奇异摄动,得到了一类具有反馈控制的广义Logistic时滞系统的唯一正平衡态渐近稳定和发生Hopf分支的充分条件,通过若干实例验证了理论分析和数值计算的一致性。     

LHAASO-WFCTA硅光电倍增管增益温度漂移精确补偿方法

大型高海拔空气簇射观测站(Large High Altitude Air Shower Observatory,LHAASO)的广角切伦科夫望远镜阵列(Wide Field of View Cherenkov Telescope Array,WFCTA)采用新型的固态半导体探测器硅光电倍增管(silicon photomultiplier tube,SiPM)作为光敏探测器.由于SiPM的增益对温度较为敏感,为使SiPM增益在变温环境下保持稳定,本文研究出了SiPM增益温度漂移的精确补偿方法.该方法通过粗调和细调两个数字电位器的方式实现对低压差线性稳压器(low dropout regulator,LDO)输出偏压的调节,并根据刻度出的模数转换器(Analog-to-Digital Converter,ADC)监测值与真实偏压的关系,利用ADC的监测值进行反馈调节的方法实现偏压的精确调节,最终实现SiPM增益的精确补偿.通过使用以该方法实现的电路后,在相似温度变化范围内,SiPM的增益波动由补偿前的71.8%降低至0.8%.结果显示该方法能够实现对因温度引起的SiPM增益漂移的很好的补偿.     

空间站姿态控制/动量管理的神经网络反馈线性化控制

考虑不确定性的空间站ACMM问题是一类较为困难的非线性控制问题.论文给出了基于神经网络反馈线性化的ACMM控制器,采用Lyapunov稳定性理论进行控制器的稳定性分析,通过考虑转动惯量偏差和转动惯量变化的ACMM仿真结果验证了该神经网络反馈线性化控制器的鲁棒性和有效性.     

Conclusion: New Directions Through Extending Deliberative Democracy to Enhance Representation and Accountability

Two way, systemic dialogue enables new ideas to emerge. Rorty (1989) in ‘Contingency, irony and solidarity’ argues that we need to ask questions that acknowledge solidarity with other human beings who suffer. He asks us to consider the consequences for humanity by widening our sense of solidarity or links with others. Considering their pain should be our starting point for drawing ever widening circles of solidarity. The issue is not idealism versus pragmatism as Rorty argues; it is about widening our understanding of the consequences of our thinking and our practice. We need to understand that the environment of which we are part has been shaped by our social, cultural, political and economic decisions and that it will in turn shape our thinking and practice. This is the principle of co-determination that has been developed by systems thinkers such as Maturana and Varela and understood by recent thinkers such as Tim Flannery (2007) and Ulrich Beck (1992, 1997).