Robust FOPID controller design for fractional‐order delay systems using positive stability region analysis

In this paper, a robust fractional‐order PID (FOPID) controller design method for fractional‐order delay systems is proposed based on positive stability region (PSR) analysis. Firstly, the PSR is presented to improve the existing stability region (SR) in D‐decomposition method. Then, the optimal fractional orders λ and μ of FOPID controller are achieved at the biggest three‐dimensional PSR, which means the best robustness. Given the optimal λ and μ, the other FOPID controller parameters k_p, k_i, k_d can be solved under the control specifications, including gain crossover frequency, phase margin, and an extended flat phase constraint. In addition, the steps of the proposed robust FOPID controller design process are listed at length, and an example is given to illustrate the corresponding steps. At last, the control performances of the obtained robust FOPID controller are compared with some other controllers (PID and FOPI). The simulation results illustrate the superior robustness as well as the transient performance of the proposed control algorithm.     

计算机集成产品工程CIPE

为了提高现代企业的竞争力，近年来人们不断提出各种新哲理和新模式以满足现代企业竞争的需要，计算机集成产品工程（ＣＩＰＥ）是我们结合近几年的研究和实际工作，在德国合理化工程和产品开发方法的基础上提出一种新的设想。对ＣＩＰＥ进行了介绍，分析了ＣＩＰＥ产生的背景，讨论了ＣＩＰＥ的定位，研究了ＣＩＰＥ的基本原理和体系结构，总结了实施ＣＩＰＥ所产生的效益。     

基于PSRT与Elman神经网络的短期负荷多步预测

短期负荷预测(short-term load forcastings,STLF)对电力系统的经济和安全运行有着重要的作用。为提高短期负荷预测的精度,根据短期负荷的基本特性,提出了一种将相空间重构理论(phase space reconstruction space,PSRT)与Elman神经网络相结合的短期负荷多步预测模型。首先利用PSRT重构相空间的吸引子,然后用Elman神经网络来拟合相空间吸引子的多步演化,其中利用空间欧氏距离来选取Elman网络的输入样本。通过对广西电网短期负荷预测的分析表明,该多步预测方法是有效可行的。     

Soil moisture mapping and AMSR-E validation using the PSR in SMEX02

Field experiments (SMEX02) were conducted to evaluate the effects of dense agricultural crop conditions on soil moisture retrieval using passive microwave remote sensing. Aircraft observations were collected using a new version of the Polarimetric Scanning Radiometer (PSR) that provided four C band and four X band frequencies. Observations were also available from the Aqua satellite Advanced Microwave Scanning Radiometer (AMSR-E) at these same frequencies. SMEX02 was conducted over a three-week period during the summer near Ames, Iowa. Corn and soybeans dominate the region. During the study period the corn was approaching its peak water content state and the soybeans were at the mid point of the growth cycle. Aircraft observations are compared to ground observations. Subsequently models are developed to describe the effects of corn and soybeans on soil moisture retrieval. Multiple altitude aircraft brightness temperatures were compared to AMSR-E observations to understand brightness temperature scaling and provide validation. The X-band observations from the two sensors were in reasonable agreement. The AMSR-E C-band observations were contaminated with anthropogenic RFI, which made comparison to the PSR invalid. Aircraft data along with ancillary data were used in a retrieval algorithm to map soil moisture. The PSR estimated soil moisture retrievals on a field-by-field comparison had a standard error of estimate (SEE) of 5.5%. The error reduced when high altitude soil moisture estimates were aggregated to 25 km resolution (same as AMSR-E EASE grid product resolution) (SEE ∼ 2.85%). These soil moisture products provide a validation of the AMSR retrievals. PSR/CX soil moisture images show spatial and temporal patterns consistent with meteorological and soil conditions. The dynamic range of the PSR/CX observations indicates that reasonable soil moisture estimates can be obtained from AMSR, even in areas of high vegetation biomass content (∼ 4-8 kg/m2).     

一种基于电源纹波前馈的高PSR的LDO

功率管栅端寄生电容的存在使得LDO的电源抑制特性(PSR)在中高频段变差。在前馈纹波抵消技术的基础上,通过在误差放大器输出端与功率管栅端之间引入具有低输出阻抗的电压跟随器,拓展了PSR带宽,实现了中高频段的高电源抑制特性。采用箝位电路,进一步提高了重载下的环路增益,保证负载范围内LDO在中高频段均具有较高的PSR。基于0.5 μm CMOS工艺进行设计与仿真。结果表明,LDO的最大静态电流为80 μA,功率管的压差电压为150 mV,负载电流范围为50 μA~25 mA。在25 mA负载电流下,LDO的PSR在100 kHz时为-63 dB,在10 MHz时为-57.5 dB。     

一种用于LDO稳压器的共享预稳压电路

提出了一种用于LDO稳压器的共享预稳压电路.该共享预稳压电路中包含一个电源抑制减法电路以提高基准源的电源抑制,应用电流负反馈结构以降低基准源的温度系数和电源抑制随工艺阈值电压变化的敏感度,还可以降低LDO稳压器的输出噪声.仿真结果表明在阈值电压发生士20％变化的情况下,基准源的温度系数变化只有0.11×10-6/℃,电...     

基于PSR模型的湖泊环境治理绩效评价及其应用

中共中央办公厅、国务院办公厅于2018年1月4日印发了《关于在湖泊实施湖长制的指导意见》的通知,然而湖长制自推行以来,政策落实不到位且湖泊环境治理效果也不乐观。在此背景下,为进一步定量评价湖泊环境治理的绩效,论文在环境、经济、社会三维价值取向的指引下,基于PSR（pressure state response）模型,从压力、状态、响应3个维度构建湖泊环境治理绩效评价指标体系,运用层次分析法确定各级指标权重,并结合模糊综合评价法对安徽省天长市高邮湖的环境治理绩效展开评价应用。评价结果显示：高邮湖环境治理绩效总体得分为0.529 8,环境治理绩效处于“警戒”状态;二级指标中的“污染物排放”“富营养化”“水质控制”的得分都只有0.3,环境治理绩效处于“较差”水平,这表明高邮湖环境治理中的短板就是污染物排放问题、富营养化问题和水质控制问题;三级指标中的“固体废物排放强度”“水土流失率”“人口密度”“人口城市化水平”“综合营养状态指数”“固体废物处理率”“重要饮用水水源地水质达标度”得分均低于0.5,进一步说明了高邮湖目前存在的具体问题,即高邮湖在长期周边人类活动的影响下对于固体废物排放控制和处理不到位,导致水土流失面积较大,湖泊整体处于富营养化状态且重要饮用水水源地水质不达标。基于以上结论,提出从源头控制污染物和水土流失、重视富营养化问题、建立信息化管控平台、促进人口与环境协调发展、强化湖泊环境绩效评价结果与问责运用、建立高邮湖各水域湖长统一管理体制等建议,以期提升高邮湖环境治理绩效。     

融合景观特征识别和景观健康评价的景观管护方法——以鄂西北秦巴山区为例

【目的】快速的城镇化进程使自然景观产生了巨大改变，对景观变化进行科学管护已成为亟须解决的问题。景观特征识别是管护景观变化的重要工具，健康评价是诊断区域景观环境问题的基础。针对现有健康评价研究的不足，尝试以景观特征识别为框架，试图构建一套区域尺度下的景观健康评价方法，用于指导宏观尺度的景观管护。【方法】以鄂西北秦巴山区为例，首先对其进行景观特征类型和景观特征区域的识别。随后围绕景观健康的问题，基于压力-状态-响应（pressure-state-response, PSR）模型，从景观特征改变面临的压力、景观特征的构成与格局状态以及政策响应3个方面选取指标，构建景观健康评价体系。【结果】最终，划定出研究区26种景观特征区域，以及5个景观健康等级。结果表明，各单元景观健康综合指数为0.40~0.75，平均景观健康综合指数为0.61。鄂西北秦巴山区西部整体景观健康优于东部，西南部表现最佳，不健康、亚健康、健康、较健康和很健康的景观特征区域分别占研究区总面积的14.4%、23.0%、23.8%、24.6%和14.2%。【结论】揭示研究区景观健康现状与胁迫因子，同时结合上位规划和区域现状，提出基于不同景观健康等级的“一区一策”分级分类管护模式与原则，并总结部分代表性景特征区域的整治策略，以期为区域景观管护提供依据。     

长江经济带产业绿色发展等级评估

为贯彻落实长江经济带“十六字”治水方针，在发展中处理好资源利用与环境保护的问题，利用压力-状态-响应(PSR)模型构建评价指标体系，结合熵权法、可变集法和偏联系数方法分析长江经济带各省市在2008—2017年产业绿色发展指标、发展等级和分布规律，构建长江经济带产业绿色发展评估体系。结果表明，长江经济带产业绿色发展水平整体向好，不同流域范围内部发展水平存在差异，上、中、下游的产业绿色发展水平依次向好。