基于输入输出模型广义预测控制的并行算法

本文提出了脉动算法实现基于输入输出模型的参数辨识及广义预测自校正控制，给出了相 阵列结构７工行实现这些算法，时序分析表明该方法可使广义预测自校正控制的实时性得到很大提高。     

变风量空调末端广义预测自校正控制

变风量空调具有非线性、大延时、时变等特点,被控对象的精确数学模型难以建立,对于此类系统常规PID控制难以取得理想控制效果。为了提高变风量空调控制的稳定性、保证室内舒适,将广义预测自校正控制应用于变风量空调末端控制。考虑到系统具有时变性,采用变遗忘因子最小二乘法在线辨识系统参数,实现在线自校正功能;采用隐式求解方法,减小了广义预测算法的计算量;结合串级控制结构,以变风量空调末端风阀开度为中间被调量,设计了串级广义预测自校正控制。建立变风量空调房间和末端装置的数学模型,在此基础上进行仿真研究。仿真结果表明,广义预测自校正控制具有较强的跟踪性能、抗干扰能力及鲁棒性,能够满足变风量空调末端的控制要求。     

基于神经网络的时滞非线性系统的广义预测控制

针对一类时滞非线性被控对象,提出一种基于RBF神经网络的广义预测自校正控制方案,在广义预测控制中,采用RBF神经网络建立被控对象的多步预测模型,并不断修正预测输出,提高预测输出的精度.控制器则采用GPC隐式修正算法,不用辨识对象的模型参数,大大减少了计算量.经过仿真研究,与常规的PID自适应控制方法相比较,证明了该方法的优越性,预测控制误差小,实时性好,动态响应快.     

时变分数时滞系统最优预报自校正极点配置PID控制算法*

本文在广义模型描述被控过程的基础上,利用广义预测理论克服时滞,增强控制系统的鲁棒性,提出一种最优预报自校正极点配置PID控制新算法,仿真结果表明这种控制策略对具有未知或时变分数时滞系统是很有效的。     

快速预测控制算法及在单回路数字控制器中的应用

为使先进的预测控制算法在工业过程单回路数字控制器中方便有效地实现，本文设计了一种快速预测控制算法，降低了控制律在线运行的计算理，了算法实现所需的存储空间，且同时具有良好的适应性和鲁棒性，基于此算法的单回路数字控制仪表“广义预测自校正单回器调节器”在工业现场投入试运行，控制效果好，具有广泛的应用推广价值。     

稀土萃取过程的广义预测解耦控制

考虑稀土萃取过程具有多变量、强耦合特性,提出一种基于广义预测解耦控制(GPDC)的稀土萃取过程控制方法.首先针对模型未知的强非线性稀土萃取过程,构建基于极限学习机的组分含量系统模型,并依据模型特点设计多个稀土萃取过程GPDC控制器;然后为降低各控制回路间的耦合性,在控制器的性能指标中引入校正策略,通过回路中模型预测值与...     

基于IGPC的时变大时滞系统自适应控制

针对工业过程中常见的参数时变和大时滞问题,研究了广义预测控制算法在其中的应用问题。为了克服普通广义预测控制算法计算复杂的缺点,采用隐式广义预测控制算法(IGPC)通过直接辩识控制器参数求解最优控制增量,具有计算量小、计算速度快的特点。仿真结果表明,在不需要关于被控对象的先验知识的情况下,隐式广义预测自校正控制器能很好地跟踪设定值的变化,当参数时变时仍具有很好的控制性能,适合于实现时变大时滞系统的自适应控制。     

隐式自校正广义预测控制器及其全局收敛性

通过引入等价性能指标,给出了一种基于CARIMA模型、考虑模型误差的隐式自校正广 义预测控制器.并通过构造两个辨识器,使控制器的全部参数能递推估计.文末给出了当采 用改进型最小二乘法和随机逼近法估计参数时的自校正广义预测控制隐式算法的全局收敛 性证明.     

具有比例积分结构的广义预测自校正控制器

本文通过对一般预测控制中目标函数的改进，导出了具有比例积分结构的广义预测自校正控制器，从而极大地改善了控制器性能。仿真结果表明了该算法的有效性，对促进自校正控制器在工业中的应用具有一定意义。     

双率CARMA模型的广义最小方差自校正控制

针对一类双率采样的CARMA模型,研究了相关的自校正控制问题。基于双率采样以及含有噪声的数据,本文提出一个辅助模型来估计无法采样到的损失输出数据,并进一步采用随机梯度算法来估计模型参数。通过最小化最优预测输出的方差并结合Diophantine方程给出了基于辅助模型的广义最小方差自校正控制(AM-GMVSTC)策略。最后通过一个仿真例子说明提出算法的有效性。     

MDA盐水处理系统的废料最小化

MDA生产过程中产生大量含苯胺、MDA废盐水,需进行萃取、汽提处理,以回收大部分有用组分.本文建立了MDA盐水处理系统废料最小化问题的严格数学模型,此模型属于多目标混合整数非线性规划(MOMINLP),求解比较困难.运用基于多目标遗传算法的过程综合3层次解算策略对MDA盐水处理系统的废料最小化问题进行求解,得到了非劣解曲线.非劣解曲线由3部分组成,分别代表了3种萃取流程.对影响利润目标的价格系数进行灵敏度分析,表明回收产品胺的价格变动对利润影响最大,蒸汽价格其次,而设备费用最小,由于使用严格过程模型,本文研究结果能为工程设计提供依据.     

RETRACTED ARTICLE: Prediction compressive strength of Portland cement-based geopolymers by artificial neural networks

In the present study, compressive strength results of geopolymers produced by ordinary Portland cement (OPC) as aluminosilicate source have been modeled by artificial neural networks. Six main factors including NaOH concentration, water glass to NaOH weight ratio, alkali activator to cement weight ratio, oven curing temperature, oven curing time and water curing regime each at 4 levels were considered for designing. A total of 32 experiments were conducted according to the L32 array proposed by the method. The neural network models were constructed by 10 input parameters including NaOH concentration, water glass to NaOH weight ratio, alkali activator to cement weight ratio, oven curing temperature, oven curing time, water curing regime, water glass content, NaOH content, Portland cement content and test trial number. The value for the output layer was the compressive strength. According to the input parameters in feed-forward back-propagation algorithm, the constructed networks were trained, validated and tested. The results indicate that artificial neural networks model is a powerful tool for predicting the compressive strength of the geopolymers in the considered range.

     

内容分发网络性能测量方法研究与实现

内容分发网络 (CDN)是新型的网络加速技术 .提出了一种新的 CDN性能测量方法 :将 CDN性能测量融入到网络测量基础设施之中 ,CDN提供者、内容提供者或终端用户可以根据需要随时、方便的测量、评价 CDN性能 ,克服了以往测量方法测量周期长、测量规模扩展性差以及数据资源利用率低等缺点 .基于此方法 ,设计并实现了一个集成在 CNMI下的 CDN性能测量系统 :CDNPMS,系统使用灵活简单 ,可以从 CDN外部测量用户感知的 (Client- perceived) CDN性能 ,并且用此系统对目前最大的 Akamai CDN进行了成功测量 .     

一种基于GIS的地球化学数据处理新方法及应用

快速准确有效的数据处理方法是日益增长的地学数据为成矿预测工作提出的迫切要求。提出了一种基于GIS的地球化学数据处理新方法,克服了传统统计分析方法对样本数据要求服从正态或对数正态分布,处理结果受少数特高品位数据影响的缺点。通过凤凰山铜矿地球化学数据处理的对比分析,认为该方法具有较好的抗干扰和致矿异常分辨能力。     

冻结站中盐水流量和温度的模糊解耦控制

针对现有冻结站盐水流量和温度控制方法存在控制精度低的问题,提出了一种盐水流量和温度的模糊解耦控制方法。首先根据盐水流量和温度控制精度的不同,采用模糊控制法对流量和温度进行模糊控制;然后分析和研究盐水流量和温度间的耦合关系,采用解耦控制法对模糊控制输出的流量和温度进行解耦控制。仿真结果表明,该控制方法无需对盐水流量和温度建立精确数学模型,可实现盐水流量和温度的解耦控制,控制精度高。     

Mixed Volume Element-Characteristic Fractional Step Difference Method for Contamination from Nuclear Waste Disposal

A nonlinear system with boundary-initial value conditions of convection–diffusion partial differential equations is presented to describe incompressible nuclear waste disposal contamination in porous media. The flow pressure is determined by an elliptic equation, the concentrations of brine and radionuclide are formulated by convection–diffusion equations, and the transport of temperature is defined by a heat equation. The pressure appears in convection–diffusion equations and heat equation in the form of Darcy velocity and controls the physical processes. The fluid pressure and velocity are solved by the conservative mixed volume element and the computation accuracy of Darcy velocity is improved one order. A combination method of the mixed volume element and the approximation of characteristics is applied to solve the brine and heat, where the diffusion is discretized by a mixed volume element method and the convection is treated by the method of characteristics. The characteristics can confirm strong computation stability at sharp fronts and it can avoid numerical dispersion and nonphysical oscillation. Larger time-steps along the characteristics are shown to result in smaller time-truncation errors than those resulting from standard methods. The mixed volume element method has the property of conservation on each element and it can obtain numerical solutions of the brine and adjoint vectors. The radionuclide is solved by a coupled method of characteristics and fractional step difference. The computational work is reduced greatly by decomposing a three-dimensional problem into three successive one-dimensional problems and using the algorithm of speedup. Using numerical analysis of priori estimates of differential equations, we demonstrate an optimal second order estimate in \(l^2\) norm. Numerical data are appropriate with the scheme and it is shown that the method is a powerful tool to solve the well-known problems in porous media.     

Fast generation method of 3D scene in Chinese landscape painting

The three-dimensional (3D) modeling of Chinese landscape painting is of great significance for the digital protection of cultural heritage and the production of virtual reality content. A fast modeling method to create 3D landscape scenes for traditional Chinese painting is proposed in this paper, based on integrated terrain modeling and the water flow rendering algorithm. A height map generation algorithm based on auxiliary lines is first proposed to carry out fast modeling from a simple two-dimensional contour to create a 3D mountain model. A realistic flow simulation that fits the topography is then undertaken, based on a flow chart which is calculated using the particle force in the normal grid of topography, and the theory of smoothing particle hydrodynamics. Finally, a stylistic scene that conforms to the artistic concept of traditional Chinese painting is acquired by optimizing the parameters. The interactive modeling platform of the integrated algorithm is tested in this study, and compared with existing research. Results show the method can achieve real-time rendering and realistic rendering to rapidly generate a 3D scene model consistent with a traditional painting scene, and provide support for the follow up development of virtual reality applications.

     

基于CCD技术的溶液质量分数检测的研究

介绍了线阵CCD传感特性和CCD驱动时序;设计了一种新颖的基于嵌入式单片机的线阵CCD驱动电路、CCD输出模拟信号采集为一体的溶液质量分数检测系统。给出了该系统硬件原理图,分析了系统工作原理。通过CCD读取碱溶液的密度值,查表获取碱溶液的质量分数。     

Stochastic evolution of regulation errors in a boundary-actuated desalination plant

A desalination plant – considered in two configurations (once-through and brine recirculation) – is modelled and controlled using a system of coupled PDEs that describe the desalination processes. The analysis is conducted in two separate parts. First, the operating point of the plant is obtained based on the deterministic process models of the plant. The steady-state distillate production is optimized with respect to a reference pressure head (operating point) that is achieved by applying relatively simple boundary controls. Both deterministic plant configurations are compared in term of characteristic numbers that evaluates the energy-efficient operation of the plant. In particular, those are the thermal ratio and the specific flow rate, where gains of roughly 5.5% and 21.5% are obtained in favour of the brine recirculation plant. The pressure head is subject to turbulence phenomena that disturb its surface so that a deterministic model is an insufficient representation of the real-case scenario. Concerning the second part of the paper, the effects of turbulence are incorporated through stochastic elements given as generalized and cylindrical Wiener processes located on the boundaries and throughout the plant (subdomain), respectively. The pressure head residual is defined as the difference between the deterministic and stochastic system. As both systems are actuated by the same type of boundary controls, the residual field is interpreted as a measure of a regulation error. It is statistical characterization is done spatially by means of the first four statistical moments (sampled) and temporarily with the autocorrelation function. It is found that the applied boundary controls are robust enough to keep the regulation error within tight bounds throughout the whole subdomain of the plant. Throughout the plant, the spatial standard deviation (std) is less than 0.3.     

扭杆刚度自动测量系统的研究与开发

针对扭杆刚度的测量,提出了一种全新的动态测量方法--自激动力微摆法:该方法采用正反馈使扭杆自激,通过测量扭杆扭摆系统的固有频率来计算扭杆的刚度;通过对扭摆系统的工作原理和自动测量的方法进行研究,开发了一套扭杆刚度自动测量系统,实现了扭杆刚度的自动测量,解决了扭杆生产中的瓶颈,提高了扭杆的生产效率,满足了扭杆批生产的要求.