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Identification of Intermittent Dryring of Grain and Adaptive Control

粮食间歇干燥的识别及自适应控制

基本信息

批准号：
03660261
负责人：
TOYODA Kiyohiko
金额：
$ 1.41万
依托单位：
Kobe University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1993
项目状态：
已结题

项目摘要

To develop the controlling method which accomplish efficient drying with good quality of dried grain and suppress the influences of variations of initial moisture content of grain and drying air temperature, the followings were investigated :1.System indentification of drying processSpace state models were investigated of thin-layr drying, drying of the thick-layr assumed as series of a thin-layr and thick-layr drying expressed by an approximated drying equation. As a result, moistrure content of grain in drying could be stably estimated by Kalman filter from the measurement of the inlet and outlet air temperature.2.Quality modellingGeminability of grain was adopted as a quality index and the relationship between geminability of grain, initial moisture content and temperature of grain was formulated. With the formulated equation, the allowable temperature of drying air was obtained to maintain a high geminability with a decrease in moisture content of grain.3.Design and estimation of multivariables controlling systemRule oriented adaptive control system was investigated which control drying control drying air temperature determined by the quality model and the residence time of grain in a drying chamber determined by the two-tank model. As a result, the control system of residence time of grain by a PI feedback method was developed in which the moisture content of grain at the outlet of drying chamber is estimated from the inlet and outlet air temperature and the grain temperature, and the moisture content of grain is controlled at the estimated value. The control system shows the good responsibility to the variation of initial moisture content and drying air temperature.As future problems, modelling of other quality indexes to extend application of the control system and the improvement of estimation accuracy remain. The author is planning and preparing a developmental study as the application of the control system to actual fields.

为了开发实现高效干燥、优质干燥粮食的控制方法，并抑制粮食初始含水量和干燥空气温度变化的影响，进行了以下研究：1.干燥过程的系统辨识研究了薄层干燥、假设为一系列薄层干燥的厚层干燥和用近似干燥方程表达的厚层干燥的空间状态模型。结果表明，卡尔曼滤波器可以根据进、出口空气温度的测量稳定地估计干燥过程中谷物的水分含量。2.质量建模以谷物的发芽率作为质量指标，建立了谷物发芽率、初始含水率和谷物温度之间的关系。通过公式，得到了干燥空气的允许温度，以保持较高的成芽率，同时降低谷物的水分含量。3.多变量控制系统的设计和估计研究了面向规则的自适应控制系统，该系统控制由质量模型确定的干燥控制干燥空气温度和由两罐模型确定的谷物在干燥室中的停留时间。因此，开发了采用PI反馈法的谷物停留时间控制系统，该系统根据进、出口空气温度和谷物温度估计干燥室出口处谷物的含水量，并将谷物含水量控制在估计值。控制系统对初始含水量和干燥空气温度的变化表现出良好的响应能力。作为未来的问题，对其他质量指标进行建模以扩展控制系统的应用和提高估计精度仍然存在。作者正在计划和准备一项将该控制系统应用到实际领域的开发研究。