总线式智能PID控制仪

论文编号:JD574 附外文翻译,开题报告,任务书,实习报告,原理图,论文字数:25636,页数:62

摘 要
随着生产过程向连续化、大型化、复杂化方向发展，对控制要求更高，加之各种新型控制方案及先进控制规律不断运用于实践，传统仪表难以胜任，其局限性变得十分突出。随着现场总线控制系统的发展，现场总线智能仪表应运而生的，并且得到了迅速的发展。采用得到了广泛应用的智能PID控制理论，作为系统的主要控制部分。在电路设计中，采用了+5V和+15V的电源电压电路和看门狗电路；在信号的输入部分，采用差动放大电路和A/D574，可以得到误差较小的信号，而且分辨率高；输出部分，采用了TLC5616和输出放大电路。由于键盘个数较少，采用了结构简单实用的独立键盘；而数码管显示较多，为了节省IO口线，因此采用动态显示电路。为了实时对信号变化实施监控，并且实现单片机和上位机的通讯，采用环境的适应性较强和性价比高的RS485总线。

关键词   现场总线  智能仪表  PID控制  单片机  RS485总线  动态显示
 

Title           Bus  Intelligent  PID  Controller      

Abstract
With the production process to the continuous, large, complex development, the requirements of control need to be higher, plus all kinds of new control scheme and the application of advanced control law to the practice continuously, the traditional instruments come to be competent, their limitations become very prominent. With the fieldbus control system,s development, fieldbus intelligent instrument came into being, and have achieved rapid development. The theory of intelligent PID control that has been widely used was applied, as the system,s main part of the control. In the Circuit Design, +5 V and +15 V voltage circuit and watchdog circuit were used; in the input part of the signal, a differential amplifier circuit and A/D574 were applied, so it can be smaller error signal and has high resolution;in the output part used the TLC5616 and output amplifier. As the number of the keyboard is smaller, used a simple structure for the independent keyboard. But the digital display are more, in order to save IO mouth lines, a dynamic show circuit was used. In order to implement the real-time monitoring of the signal changes, and in order to achieve communications of the single chip and the PC, used the environment adaptative and more cost-effective of the RS485 bus.

Keywords  Fieldbus  intelligent instrument  Proportion Integral Differential control  independent keyboard  single chip  dynamic display
目   录

1  引言……………………………………………………………………………………1
1.1  课题背景及意义……………………………………………………………………1
1.2  PID控制简介…………………………………………………………………………1
1.3  现场总线……………………………………………………………………………3
1.4  单片机特点及其应用范围…………………………………………………………4
1.5  本章小结……………………………………………………………………………5
2  系统设计的主要内容…………………………………………………………………7
2.1  现场总线和现场总线控制系统的现状及发展……………………………………7
2.2  系统的组成及工作原理…………………………………………………………… 10
2.3  系统各主要功能模块………………………………………………………………12
2.4  本章小结…………………………………………………………………………… 31
3  总线式智能PID控制仪的软件设计…………………………………………………32
3.1  主程序模块…………………………………………………………………………32
3.2  初始化子程序………………………………………………………………………33
3.3  A/D转换子程序……………………………………………………………………33
3.4  键盘程序……………………………………………………………………………34
3.5  LED数码管显示程序………………………………………………………………35
3.6  系统通信部分设计…………………………………………………………………36
结论………………………………………………………………………………………38
致谢………………………………………………………………………………………39
参考文献…………………………………………………………………………………40
附录A  程序清单…………………………………………………………………………41
附录B  硬件原理图………………………………………………………………………62