【作者】 李佳怡；

【导师】 马彦；

【作者基本信息】 吉林大学 ， 控制工程， 2011， 硕士

【摘要】 控制系统性能评估的理论研究在过去十年里吸引了许多研究人员和学者的关注。因此,相关评价方法得到了迅速的发展,相继出现了不少新的研究成果。但是,关于控制器性能评价技术的研究领域仍然存在着一些尚未解决的问题,从而限制了性能评价技术在工业过程中的广泛应用。因此,本文从实际应用出发,在前人的研究成果的基础上,尤其是对以最小方差为基准的性能评价方法进行了深入的探索。目前,如何利用性能评估方法评价汽车中的控制回路逐渐成为炙手可热的研究课题。本文采用基于最小方差算法对汽车发动机中空燃比回路进行性能评估,依据目标的性能指标来缩小控制器的参数范围,以达到更好的控制空燃比的目的。本论文以最小方差基准理论研究为基础,将其应用于空燃比系统模型,实现对空燃比控制回路的性能评估,最后给出基于此算法评估的Matlab仿真。主要研究工作包括:1.首先,介绍了性能评价领域的历史与研究现状,以及课题的研究方向及意义。2.简要分析了性评价控制性能算法优劣的因素,总结归纳最小方差算法的历史与现状,并对单输入单输出(SISO)和多输入多输出(MIMO)系统的最小方差算法性能评价方法进行理论推导。3.确定评估算法与性能指标后,根据空燃比系统模型确定每个变量与控制变量之间的转换关系,然后获得输出数据和延迟时间估计。4.根据这些获得的信息进行以最小方差为基准的性能指标的计算,并在Matlab中进行仿真实验,评价在所选定的控制器下系统性能的好坏。通过对性能指标的统计规律来分析,定量地给出了可以接受的控制性能指标的上下限,并确定该性能指标下对应控制器参数所能达到的范围。在文章的结尾,总结了自己所做的工作,对下一步的研究方向做了进一步的展望。更多还原

【Abstract】 Performance assessement of control systems in the past two decades has attracted many researchers and scholars. Therefore, the relevant assessment methods have been developed rapidly, and also considerable new research results have obtained. However, there are still many unresolved issues on the field of controller performance assessment techniques, which limits the wide range of application in process industry. Therefore, this paper proceeds from the view of practical application, based on the results of previous researchers, and especially explores deeply the minimum variance(MV) based performance assessment.Currently, how to use the performance assessment for evaluating vehicle control loops has been one of most active research topic. This paper adopts the algorithm of MV based performance assessment to evaluate the air-fuel ratio control loop of gas engine. Base on expected performance index, the scope of the controller parameters can be narrowed to achieve the purpose of better control of air-fuel ratio. It can also expand the application scope to increase the applicability. The paper is arranged as follows: first, the theory of MV benchmark is reviewed, which will be applied to the air-fuel ratio system model. Then the optimal values of the parameters in the range of air-fuel ratio control loop are obtained. Last, the simulations of system base on this algorithm in Matlab are given. The main work includes:1.The history and current status of the field of performance assessment is presented, as well as the direction and significance of the research topic.2.The factors of the merits and limitations of different control performance algorithms are analysed, the history and current status of MV algorithm is summarized, and also the theoretical derivation of MV algorithm of SISO and MIMO systems are given.3.After the determination of the algorithms and the performance indicators, determine the conversion relationship between each variable and control variables based on the model of air-fuel ratio systems, then obtain output data and estimation of time delay.4.According to the obtained knowledge, the MV performance index is calculated, Matlab simulation are carried out as well, which are used to evaluate the system work in a good or bad condition under the selected controller. By analysing the statistics laws of performance assessment, the acceptable upper and lower control performance indicators are quantitatively given. And the performance can be achieved under the corresponding range of controller parameters to achieve this ultimate goal of this paper.Finally, sum up the work that I have done, and make further prospects on the future research directions.更多还原