基于人工智能的温室环境控制算法

温室环境控制系统的最大特点是控制对象的精确数学模型很难建立。文章将常规PID控制算法与现代控制理论相结合,对常规PID算法进行改进,得到新型MPT控制算法,并加入模糊控制算法规则,在误差大时,运用模糊算法进行调节,以彻底消除PID饱和积分现象,当误差较小时,采用改进后的PID算法控制输出。同时加入了自适应调节规则和自整定专家系统,建立了基于人工智能的温室环境控制算法。将此算法应用于温室环境控制。系统具有无超调和控制精度高等特点。     

基于PID算法对热风炉热风温度控制及仿真分析

在农作物金银花干燥期间,为了满足干燥热风的温度和风速的稳定性要求,针对热风炉出风口热风温度与设定的温度值滞后和稳定性差等问题,设计了一套以单片机STM32作为核心处理器和模糊自适PID算法作为参数控制器的控制系统,实现模糊自适PID算法对参数进行调整。利用Matlab语言建立模型,对整套控制系统进行仿真分析。结果表明:出风口热风温度的稳定性能达到95%以上,该研究方法提高控制系统的性能,有利于农作物干燥的质量和效率。     

酥饼烤制温度的控制模型及仿真分析

金华酥饼有着千年历史,以传统的烤炉制作为主。基于现阶段酥饼生产中"烤"无法用现代技术替代,如果能将传统炉的温度控制复制到现代炉,将解决酥饼烤制的关键问题。通过对传统炉烤过程中的空气温度和炉壁温度的实测,建立烤制温度模型,利用PID控制方法,用MATLAB工具,在SIMULINK环境下进行仿真试验,经过计算和调整温度传递函数参数,得到适用于电烤温度控制的仿真曲线,为酥饼烤制的实质性研究提供条件。     

模糊控制系统的垂直切换判决算法分析

针对模糊控制系统中切换时延较长和切换次数较多的问题,研究了一种基于模糊控制系统的垂直切换判决算法。在基于信号强度判决时将RSS作为门限值,提高系统判决能力;同时,将网络参数和服务类型作为判决因素,结合层次分析法引入并行的模糊控制系统,缩短了切换判决的时间、选择适合用户的最佳网络,做出垂直切换。仿真结果表明,该算法减少了切换次数,降低了切换时延,增强了系统的性能。与传统的切换算法相比较,该算法对切换的判决因素考虑的更全面,兼顾了用户终端的使用环境及成本问题,有效地保证了网络的服务质量。     

热风干燥智能控制系统的设计

根据热风干燥工艺特性,借助自研开发的热风干燥实验台,基于PLC设计了热风干燥智能控制系统。针对热风干燥实验台温度非线性、大滞后和惯性大的特点,采用模糊—PI控制器,保证了温度控制精度和稳定性。该控制系统实现了温度、湿度、风速和干燥时间的分阶段设置和显示,趋势曲线显示和历史数据下载功能。     

履带式拖拉机自动驾驶系统路径智能跟踪控制研究

为实现复杂环境下履带式拖拉机田间作业的路径跟踪控制,设计了履带式拖拉机自动驾驶系统,并对路径跟踪与控制算法进行了研究。自动驾驶系统由MCU、双源激光定位系统、速度控制系统、点火/熄火控制系统、液压转向系统等组成。采用模糊算法对行驶过程中的路径偏差进行补偿,实现对路径的跟踪控制。为验证算法的有效性,进行了Matlab/Simulate仿真与田间试验。结果显示对于NF502型履带拖拉机,该系统在100 m范围内可实现有效控制,表明该算法能实现对行驶路线跟踪与控制。     

贵州扁形绿茶关键温度控制研究

温度控制是提高扁形绿茶品质的关键因素,为了明确贵州扁形绿茶加工工艺中关键温度的适用范围,采用L9(3)4正交实验设计,通过调控扁形绿茶加工过程中的做形温度、脱毫温度及提香温度,分析了其对扁形茶感官品质外形、汤色、香气、滋味及叶底的影响作用。实验结果表明在控制的温度范围内,做形温度50℃-70℃,脱毫温度50℃-70℃,提香温度80℃-100℃,九个处理的扁形茶感官品质没有显著性差异,说明在本实验设计的温度范围内可以保证贵州扁形绿茶的高品质。     

基于PLC的醋酸发酵过程控制

针对不锈钢转筒的醋酸发酵控制系统,优选西门子S7-1200PLC作为控制主机,通过变频器控制转筒转速,触摸屏现场操作、显示,多套PLC通过工业以太网连接,组态王组态软件模拟设备运行状态、发酵参数设置、过程数据实时记录、历史记录、故障报警及记录、双服务器冗余、故障实时切换等,研讨了固态醋酸发酵设备、固态醋酸发酵工艺、控制系统硬件、转速控制、温度过程控制、PLC之间的通讯、控制软件、计算机监控等。     

不同变黄温度对烟叶主要质量性状的影响

为改善烤烟NC297和NC102烤后烟叶的外观质量和内在品质,以这2个品种上、中和下3个部位的烟叶为材料通过控制变黄阶段干球和湿球的温度,找出2个品种优良外观质量和内在品质的形成的变黄温湿度。结果表明：烤烟NC297下部叶和中部叶,变黄温度为38℃,干湿差2~3℃的经济性状、外观质量和主要化学成分协调性最好;上部叶,除外观质量,处理1（温度为36℃,干湿差2~3℃）的经济性状和化学成分协调性最好。烤烟NC102下部叶,经济性状、外观质量和化学成分协调性均为处理3（温度为40℃,干湿差2~3℃）最好;中部叶,除化学成分的协调性,处理2（温度为38℃,干湿差2~3℃）经济性状和外观质量的协调性最好;上部叶,除化学成分的协调性,处理1（变黄温度为36℃,干湿差2~3℃）经济性状和外观质量最优。说明烤烟NC297下部和中部叶变黄阶段温度应控制在38℃,上部叶应控制在36℃;烤烟NC102下部叶变黄阶段温度应控制在40℃,中部叶应控制在38℃,上部叶应控制在36℃。     

基于PLC的液压刨毛机控制线路改造

某型号液压刨毛机控制系统是一种采用传统的继电—接触器控制,系统接线复杂,故障率高,可靠性差。介绍采用三菱公司FX1N—24MR型PLC改造的液压刨毛机控制系统。根据某型号液压刨毛机的加工工艺和工作原理,设置PLC的I/O地址,设计外部设备接线。根据原理、控制要求和特点设计系统梯形图,连接外部设备,进行调试运行,达到系统改造的要求。     

Implementation of PID Algorithm Based on MATLAB in Cascade Control System

This paper presents the character of cascade control system and the design of the main loop and subloop. A cascade PID control system based on MATLAB is designed, which is controlled by MATLAB control program based on incremental PID control algorithm and PID parameter tuning method based on computer control. The results show that the control system has good performance.     

Research to Algorithms of the Regulators in Digital Control System

The R S T algorithms structures of usual digital regulator are researched and the results are given. It has solved the problem of relationship between the digital regulator and dynamical characterization of system. It is a direct and quick algorithm of the digital regulator based on the characteristic equation of control system. This algorithm is especially suitable for numerical simulation of control system which contains digital regulator.[WT5HZ]     

智慧设施农业中控制系统的研究进展

随着科学技术的发展，农业的发展越来越趋于信息化、现代化，智慧农业是未来农业发展的必然趋势。温室控制系统是智慧设施农业的核心，是实现设施农业规模化发展、集约化生产的关键。本研究综述了温室控制相关研究进展，以期在今后的研究中起到一定的作用。温室控制系统自20世纪70年代发展至今越来越成熟，本研究对比了温室控制系统的控制算法、主控芯片、各种传感器，通过对近些年来包括控制系统在内的感知层、传输层和应用层等组成部分综述，并介绍了市面上比较主流的传感器、网络传输技术以及主控芯片，旨在为温室控制系统的设计提供一种可选择的方案，并对温室设施农业中存在的问题和未来的发展方向进行了分析和展望。     

Stiffness optimization of vehicle engine magneto-rheological fluids mounts

As important tool for engine semi-automatic isolation system, the magneto-rheological fluids (MRC) can’t achieve tunable stiffness but damping. Therefore, the MRC’s initial stiffness affects the performance of isolation system. To obtain the better isolation effect of MRC in wide frequency, it is necessary to optimize the initial stiffness. As motor unbalanced force and isolation damping are not considered in traditional mount optimization, the feature of semi-automatic control can not be reflected. For a four-cylinder four-cycle in-line diesel engine, a new method which is suitable for stiffness optimization on vehicle engine isolation is presented by using Genetic Algorithm. The optimal isolation system has small absolute force transmissibility in abroad frequency range and small vibration intensity with impact load by using the new method.     

A Study on Human Simulation Intelligent Control Algorithm to a Category of Objects

Based on the model of Human Simulation Intelligent Controller (HSIC) presented briefly, a detailed algorithm was described for the servo system control by using the method of HSIC. Simulation results obtained proves the good performance of the control algorithm.     

A NERUAL NETWORK FOR THE ADAPTIVE CONTROL OF A 2 ORDER NONLINEAR SYSTEM

This paper presents a new method of self tuning adaptive control which adopts a neural network to identify the characteristics of a second order nonlinear system, which is in turn applied to adaptive control. The simulations show that the method has good capability of sduty and adaptation.     

An Algorithm to Enhance the Performance of Data Service Over CATV Broadband Networks

Emerging CATV networks are evolution to Hybrid Fiber/Coax plants. It is widely believed that the HFC network will play an important role in providing broadband accessing service to subscribers due to it's large excess bandwidth and high penetration to the home. Asymmetry broadband data service is the main service provided in the HFC broadband access networks now. It's performance will determine whether the subscribers be satisfied or not and affect the growth of HFC broadband access networks. The authors outline the mechanism of transmitting data in the upstream channel of the HFC network, and analyze how it affecting the performance of data service. The performance of data service and TCP protocol in HFC network is examined. An optimal scheme of bandwidth allocating algorithm for the upstream channel is proposed to enhance the performance of the data service over these networks.     

PID Control for Multivariable System Based on Ameliorative RBF Neural Networks

Aiming at systems which are of characteristics of multi-input and multi-output, nonlinearity and time-variation in the industrial control fields, this paper presents a intelligent PID control method based on ameliorative RBF neural networks, which constructs RBF neural networks identifier on-line and identifies a controlled object on-line by means of adopting the nearest neighbor-clustering algorithm, and adjusts parameters of PID controller on-line and realizes decoupiing control of multivariable, nonlinear and time-variation system. The simulation result indicates that the controller can get parameters which are optimal under some control law, it makes the decoupled system, compared to the PID control method based on the conventional RBF neural networks, has perfect dynamic and static performances, possesses the advantages of high precision, quick response speed and is of great adaptability and robustness.     

L2 Controller Design for Nonlinear Systems with Dead- Zone Modification

An adaptive robust L2design method with dead -zone modification is proposed for a class of nonlinear systems with external disturbances and uncertain parameters. With priori knowledge of the bounds of the parametric uncertainties, the smooth projection method and the dead zone modification technology are incorporated into the adaptive laws to prevent parameter drifting and reduce the computation burden. The number of parameter estimates is minimal for the adaptive system. The algorithm can guarantee the tracking errors asymptotically converge to the desired dead zone if the external disturbances are zero. The system satisfies L2 disturbance rejection criterion when the external disturbances are considered.