基于PID的恒温箱温度控制系统设计说明

基于PID的恒温箱温度控制系统设计

（2008届）

2008年6月

摘要

本设计是恒温箱温度控制系统设计。可供各类实验室、医疗机构、食品加工、生产部门等使用。在周围温度不断变化条件下，使用恒温箱，可以使一定围的温度恒定在特定温度下，从而适应生活和工作。控制的温度围为50—1200C。恒温箱可以在线设定温度，并对温度进行实时数码显示。

设计容包括硬件和软件两个部分。硬件主要由AT89S52单片机、DS18B20数字温度传感器、8155片外存储器、继电器，LED数码管和报警器等组成。电原理图包括数据采集、温度显示、键盘设定、温度控制和复位电路等几个模块。软件

部分主要对PID算法进行了数学建模和编程。

本设计由键盘电路输入设定温度信号给单片机，温度信号采集电路采集现场

温度信号给单片机，单片机根据输入与反馈信号的偏差进行PID计算，输出控制

信号给加温控制电路，实现加温和停止。当实际温度比设定温度大2摄氏度以上

时，则清P1.3输出口，从而停止对电阻丝的加热。当实际温度比设定温度小2

摄氏度以上时，取PID的最大值，实现全功率输出。在它们之间时，实现PID

算法控制，控制可控硅的接触时间，调节电阻丝功率。显示电路实现现场温度的

实时监控。

软件部分，采用PID控制和时间最优控制相结合的控制方案，实现了控

制速度快、超调小、线性控制精度高和实现成本低等的优点。硬件部分采用单

片机来实现温度控制，不仅具有控制方便、简单、灵活等优点，而且可以大幅

度的提高被控温度的技术指标，从而大大提高产品的质量。

关键词：恒温控制，单片机，数字PID算法

ABSTRACT

The system of this design is the temperature controller of a constant temperature box.Can be provided as each kind of laboratory, medical treatment organization, food processing and produce the section etc. usage.Under the condition that the surroundings temperature continuously change, the usage constant temperature box, can make the temperature maintaining of the certain scope settle under the particular temperature, thus adapt the life and works.The temperature scope of the control is 50-120, The constant temperature box can with on-line enactment temperature, and carry on the solid hour to the temperature figures manifestation.When be placed in to set the appearance, figures tube manifestation enactment temperature, circulate, manifestation actual temperature.

Design content including hardware and software two parts. The hardware mainly by at89S52 monolithic integrated circuit, the DS18B20 digit temperature sensor, 8155 piece of external memory, the relay, the LED nixietube and the alarm apparatus and so on is composed. Electricity schematic diagram including data acquisition, temperature demonstration, keyboard hypothesis, temperature control and reset circuit and so on several modules. The software part mainly has carried on mathematics modelling and the programming to the PID algorithm.

The circuit design of the keyboard input from the set

temperature signal to the microcontroller, Temperature Signal

Acquisition Circuit collect temperature signal to the microcontroller,

According to SCM input and feedback signal, the error for PID, the output

control signals to the heating control circuit, Heating and achieve stop. Show circuit scene of the real-time monitoring of temperature. When actual temperature compares to set temperature big more than 2 degrees , then the pureexportation, thus stop to electric resistance silk of heating.When the actual temperature compares to set smaller than 2 degrees , taking the PID biggest value, carrying out the whole power exportation.among the two , carry out the PID calculate way control, control contact time that controvable silicon , regulate the electric resistance silk power.

software part, the adoption PID control and the control project that time superior control combine together, carried out to control the speed quick, super adjust small, line control the accuracy is high and carry out the cost advantage of low etc..The hardware part adopts a machine to carry out the temperature control, not only have the control convenience, simple, vivid etc. advantage, and can is control with the significant exaltation the technique index sign of the temperature, raise the quantity of the product thus and consumedly.

Keywords:Temperature，control，microcontroller，PID，algorithm, MATLAB

目录

绪论

把温度作为被控参数进行研究无论在工业生产，还是在日常生活中，都已经变得非常适用和广泛了。在工业生产中，例如冶金工业、化工生产、电力工程、食品加工、机械制造、医疗以及科研研究室等，人们对需要对温度进行监测和控制；而日常生活中的家用电器如电烤箱、微波炉、烘干箱、保温箱等等，也是我们不可或缺的。因此，就恒温箱的研究就有极其重要的现实意义。本设计系统主