粮食干燥机控制系统设计

摘要

我国是产粮大国，水分是粮食存储的关键的参数，因此粮食的烘干成为一个非常重要的问题。本文主要研究基于89C51单片机作为模糊推理机,系统采用模糊控制算法，解决了因温度变化缓慢引起系统超调问题。首先塔式烘干机将进粮的阀门打开，当料位传感器检测到粮食达到指定的位置时，阀门将被关闭。此时加热风机进行对流加热，温度和湿度传感器采集信号，显示屏上实时显示粮食的温湿度。当粮食达到所需要的温湿度时，出粮口的阀门打开,粮食运送到外面进行缓苏，最后粮食送入粮仓储藏。

总而言之，塔式烘干机对温、湿度信号进行采集，实时显示粮食的温度和湿度，实现烘干系统及人机界面的设计，使其满足实际生产过程中的需要。在整个烘干过程中，热风对流穿透粮层，完成热交换后经排风口排出。整个系统自动化程度高、操作方便、安全。

关键词：模糊控制单片机烘干机温度传感器

Title The dryer of food

Abstract

Because of our country is a major grain-producing and the water is the key to food storage parameters, so the grain drying has become a very important problem. The system is based on the single-chip computer, 89C51, as a fuzzy inference engine, which adopt fuzzy-control algorithm. Firstly, the tower dryer open the valve，a certain location the food reached, which found by the material level sensor, the valve will be closed. At this point, the heating fan is started to heat the food convectively，and the temperature and humidity sensors start to work，the temperature and humidity of food will be shown on the screen at the same time。When the grain meet the required temperature and humidity，it pay out of the valve opening to the outside food deliveries for relief Su. Finally，the rain is delivered into the barn to store .

In a word, the tower dryer collect the temperature and humidity signal，show the temperature and humidity while real time, achieving the requirement of the design in drying system and the design of man-machine interface. Throughout the drying process, the heating wind flow from top to bottom of the grain, when the heat exchange has been completed exit from exhaust vents. The entire system has a high degree of automation，easy and safety operation.

Keywords :Fuzzy-control single-chip computer dryer temperature sensor

目录

摘要 ....................................................................................................................................... I Title The dryer of food ................................................................................................. II 第一章绪论 . (1)

1.1课题来源及意义 (1)

1.2粮食烘干机发展概况 (1)

1.3热风塔式粮食烘干机的原理及工艺 (2)

1.3.1烘干原理 (2)

1.3.2主要结构 (2)

1.3.3工艺特点 (2)

1.3.4工艺流程 (3)

1.3.5工艺要求 (3)

1.4热风塔式粮食烘干机的模糊控制系统组成 (3)

1.5模糊控制用于热风塔式粮食烘干机的原因 (4)

第二章方案论证 (5)

2.1总体方案的论证 (5)

2.1.1单回路控制系统 (5)

2.1.2复杂控制系统 (5)

2.1.3新型控制系统 (6)

2.1.4模糊控制系统 (6)

2.2传感器的原理及主要技术参数 (7)

2.2.1传感器的原理 (7)

2.2.2主要技术参数 (8)

2.3 温度传感器 (9)

2.3.1温度传感器原理 (9)

2.3.2温度传感器的选择 (10)

2.4湿度传感器 (10)

2.4.1湿度传感器原理 (10)

2.4.2湿度传感器的选择 (11)

2.5单片机选择 (17)

2.5.1微机系统选择论证 (17)

2.6控制电路 (18)

第三章硬件系统设计 (19)

3.1AT89C51的介绍和特性 (19)

3.1.1并行I/O口 (23)

3.1.2并行口的结构 (23)

3.1.3并行口的使用说明 (25)

3.2温度传感器 (25)

3.2.1 AD590简介 (25)

3.2.2 AD590的应用电路 (26)

3.2.3 温度AD590管脚 (28)

3.3 A/D转换器及其与CPU的接口 (30)

3.3.1 A/D转换器的选择 (30)

3.3.2引脚排列及各引脚的功能 (31)