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一种改进的放射性气体扩散高斯预估模型算法* 总被引:2,自引:0,他引:2
通过对放射性气体扩散的特征描述,针对高斯预估模型存在的缺点,引入了动态变化的泄漏强度,并通过夹角系数的方式将风速和放射性气体自身的扩散速度合成,得到对气体扩散起到关键作用的合成扩散速度,进而更好地模拟了放射性气体扩散过程中在不同时段、不同区域、不同气流状态下的气体浓度。最后通过实验仿真模拟,表明该算法在一定条件下能够有效地计算出放射性气体泄漏后的不同时间点和不同气流状态下的扩散浓度空间分布,能够较好地模拟放射性气体扩散的动态变换过程,对放射性气体泄漏事故现场的预测和评估具有很好的辅助决策作用。 相似文献
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目前井下危险气体巡检机器人大多采用升降机构或固定探头的形式进行气体环境感知,对机器人的行驶灵活性产生了影响,且受机器人本体结构的限制,大多数巡检机器人只能检测到传感器安装范围内的局部气体环境信息,缺乏针对巷道任意截面空间内的气体浓度检测。针对以上问题,设计了一种基于气体扩散模型的煤矿巡检机器人巷道气体环境智能检测系统。该系统以气体扩散理论为基础,结合煤矿巷道气体环境特点,引入巷道壁帮围岩、风速、气体扩散系数对煤矿巷道气体扩散模型的影响,采用虚拟像源法和遗传算法优化BP神经网络智能算法建立了巷道气体扩散优化模型。通过传感器检测系统获取巡检机器人在行进过程中任意点的气体浓度等环境信息,代入气体扩散优化模型求解最优气体扩散系数,通过输入巷道某点坐标位置,可计算求解相应点的气体浓度分布情况,随着巡检机器人的移动,可获取其路径中不同巷道截面上气体浓度分布数据。实验结果表明,该系统能够解算出符合检测误差要求的巷道任意截面上任意点的气体浓度,并实现动态实时检测;克服了传统煤矿巷道气体检测方法的局限性。利用巡检机器人取代人工巡检作业,为煤矿井下气体智能检测提供了一种新思路与新方法。 相似文献
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为了减少化学气体泄漏事故的伤害和损失,研究开发一个基于GIS的桌面应急演练系统。该系统采用基于高斯烟团模型的新模型和新数值化仿真运算算法模拟气体扩散,并采用一种车辆紧急调度模型和启发式求解算法进行人员调度疏散演练。最后,该系统在Flex架构下实现了前端交互式界面。桌面应急演练系统的研究有助于应急管理的信息化和智能化。 相似文献
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针对直拉硅单晶固液界面相变温度场的非均匀性导致晶体直径不均匀问题,提出一种基于偏微分方程(PDE)模型的温度场最优控制策略.考虑生长速率波动的影响,建立了一种改进的提拉动力学模型,确定了域边界演化动力学关系.研究基于抛物型PDE的时变空间域对流扩散过程的温度模型,描述了域运动在对流扩散系统上的单向耦合.针对无限维分布参数系统建模控制难问题,采用谱方法进行系统近似,选取整个空间域的全局和正交的空间基函数,通过Galerkin方法对无限维系统进行降维,获得了该系统的近似模型.采用线性二次型方法控制晶体生长温度,通过仿真实验对相变温度场模型进行验证.结果表明,优化后的模型能够获得较为平稳的晶体生长速率,减小了生长直径的波动,使得固液界面径向温度分布更加均匀,验证了该方法的有效性. 相似文献
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KM6环控系统的湿度调节过程的数字仿真 总被引:1,自引:0,他引:1
KM6载入试验容器环控系统是在地面实验室为宇航员提供一定的氧氮比率和一定温湿度气体的系统,该系统采用超声波雾化器为系统加湿。该文介绍了环控系统的湿度调节方法,并建立了湿度调节过程中,加湿装置的的动态数学模型、气体湿度在管路中变化的数学模型及湿度传感器的数学模型,并用这些模型在Matrixx软件上进行仿真。仿真结果表明在试验舱温度较低、压力较高的情况下,能调节的最大相对湿度较大,反之较小。在试舱温验度高于一定值、压力底于一定值的情况下,系统调节的相对湿度达不到70%,这只能通过降低试验舱温度、升高其压力;或通过降低微调室的压力来达到。 相似文献
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由于直流电机控制器是电动车中的核心部件,又是故障率最高的部件,其损坏的主要原因是车辆持续重载运行时控制器功耗过大,而控制器通常又都安装在较密闭的空间里,通风不良,散热条件差,若功耗大就会造成温度快速升高,容易发生过热损坏。针对当前直流电机控制器续流损耗大、效率低的问题,提出了基于同步续流的直流电机控制系统设计方案,通过Matlab建立系统仿真模型,进行相关仿真研究来验证方案的可行性,大量的仿真研究结果证明了设计方案的正确性。 相似文献
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跳频通信系统抗干扰性能仿真研究 总被引:2,自引:0,他引:2
跳频通信系统与常规定频通信系统相比具有较强的抗干扰能力。文中在介绍跳频通信基本原理的基础上,分析了在宽带阻塞干扰和部分频带干扰这两种常见干扰下的跳频通信系统的抗干扰性能,并借助计算机仿真工具MATLAB/Simulink搭建仿真模型,得到了在两种干扰下的误码率-信噪比曲线,从而验证了理论分析的结果。 相似文献
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《Control Engineering Practice》2006,14(8):959-974
Two soft sensors were developed for the estimation of biomass concentration and specific growth rate in fed-batch baker's yeast fermentation: one based on estimation of specific growth rate from process model, the other based on actual measurements. The first method of estimation gave satisfactory results under fixed initial condition where inoculum size was fixed. However the estimation was deviated when initial amount of seed yeast was changed under otherwise identical conditions. To overcome this problem, the second method of estimation was proposed. This method gave improved estimation even with varying initial condition. Fuzzy controller was designed based on the proposed structure using simulation model of fed-batch baker's yeast fermentation system in order to demonstrate effective use of neural soft sensors developed in this work. The controller determined substrate and air flow rate, relating to status of estimated specific growth rate, elapsed time, ethanol concentration and dissolved oxygen concentration. It has been tested on a simulated fed-batch production scale fermenter. The results demonstrated that the controller has generated substrate and air flow rates as an output acceptable in large scale. 相似文献
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相位的可辨识性及极大似然反褶积 总被引:1,自引:0,他引:1
本文所述系统有两个特点:输入为不可量测的随机信号;系统可以具有不稳定的零点或
者说系统可以是非最小相位的.文中研究了将一类输入信号与具有正确相位的脉冲响应从输
出信号中分开的条件,并对以状态空间模型为基础的极大似然反褶积方法进行了改进.利用
合成数据进行了仿真研究,仿真结果验证了非最小相位系统的可辨识性. 相似文献
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The objective of this paper was to find an effective way of improving demand-controlled ventilation (DCV) simulation performed under an occupant based ventilation standard established in many countries. Two attractive DCV approaches, CO2–DCV and RFID–DCV, were applied to DCV simulations for a theoretical public assembly space served by a dedicated outdoor air system (DOAS) with an enthalpy recovery device. A numerical model for predicting the real-time occupant number, required ventilation amount, CO2 and formaldehyde (HCHO) concentrations under given conditions was developed using a commercial equation solver program. The current ventilation standard used in Korea was applied as a case of occupant based ventilation standards. It was found that the current standard might cause unstable DCV simulation results, especially under CO2–DCV. This is because the ventilation rate (per person) indicated in the standard is the sum of the outdoor air required to remove or dilute air contaminants generated by both occupants and the buildings themselves, and not a pure function of occupant numbers. Finally, it makes DCV control unstable when ventilation flow is regulated only by the number of occupants. In order to solve this problem, the current occupant based ventilation standard was modified as a form of ASHRAE Standard 62.1-2007 showing good applicability to various DCV approaches. It was found that this modification enhances applicability of the current ventilation standard to CO2–DCV significantly and can maintain acceptable HCHO concentrations during the entire time of operation. Fan energy reduction can also be expected from DCV operations. 相似文献
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Oscar‐Oswaldo Rodriguez‐Diaz David Fernando Novella‐Rodriguez Emmanuel Witrant Edinson Franco‐Mejia 《Asian journal of control》2021,23(1):72-81
In view of the frequent ventilation network changes during production in underground mining, decreasing sensors and actuators without altering production control and safety is one of the chief engineering challenges. This work is focused on modeling identification and control strategies for underground ventilation networks in small‐scale mines using an experimental benchmark. Guidelines to obtain a discrete state space model are provided, considering the conservation laws in the network to define the structure of the linear model. The main purpose of the paper is to analyze the use of classic controllers in the mine ventilation system when there are limitations on the number of sensors and actuators available to design a feedback control system. A comparison of three classic control strategies is presented considering the a constraint on the available number of sensors. Experimental and simulation results are presented. 相似文献
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一般的控制系统可能会因为一些非线性故障转变为混沌动力学系统.液位控制系统中的比例反馈回路中存在非线性环节,使液位控制系统的运动成为混沌运动.针对这种情况下的混沌数学模型,通过仿真验证小脑模型神经元网络控制方法,仿真图说明控制方法对混沌模型进行有效控制,可以将稳态值控制到与期望值一致.同时小脑模型神经元网络具有计算速度快的优点,这种控制方法在实际工程领域中的应用值得研究. 相似文献