Design Of Real-time Controller Based On AVR And The Application Of It To The Fermentation Process

As an important embranchment of automation, process automation has improved rapidly in recent years. With the development of standard of living,the light and chemical industries like fermentation, foodstuff, textile, paper making have become research hotspots. Fermentation industry is a concernful part of the light and chemical industries As the influencing factors are intricate and the mechanism are complex in the bio-fermentation process.,it get pressing to using automatic control into the fermentation process and it has become more and more important to utilizing computer control system in on-line detection and effective real-time on-line control of bio-fermentation industry.With the development of micro-electronics technology, capabilities of Single Chip Micyoco advance fast. The controllers based on the single-chip Micyoco have been widely used in varieties of control conditions with low cost and high Quality/Price Ratio. This paper with the background of the light and chemical industries illuminates utilizing ATmega128 and ATmega64 microcontrollers of the AVR series made by ATMEL corp. to design and implement the AVR-based fermentation process controller. The proposed system has the characteristics of concise structure, strong reliability and small investment. This paper choose fermentation process as emphases depicting the details about hardware and serve program design in the system and research the relevant control theory on the principle of reliability and availability.This paper referes to the ereas below:1)Hardware design.The paper narrates opting for MCU and peripheries deponding on hardware requirements and designs PCB. The controller is constituted of a main control board and a display control board. Main control board adopts ATmega128 of AVR as its core Meanwhile display control board uses ATmega64. The controller adopts RS-232 as physics layer communication interface between the host computer and main control board,using TWI interface of AVR as communication interface between main control board and display control board.2) Software design. The paper expounds fixing the main framework, modularizing configuration, integrating bio-fermentation process control algorithm and then realizing functions like data collection,communication, malfunction self-examination and output control. In order to meet the needs of bio-fermentation process, communications between the host computer and main control board employs MODBUS protocol as its application layer protocol and makes several adjustments to it when used in USART of AVR. The main control board analyzes and manages signals captured by itself and data from display control board. It simultaneity responses abnormities and malfunctions. display control board receives signals sent by main control board ,displaying according to the commands of main control board.3)The paper introduces discussing and research fermentation process control algorithm, testing and validating the fermentation process controller on the bio-fermentation experiment platform.During the period of board making, soldering, debugging of hardware and program, reliability and stability of bio-fermentation process controller is fine, satisfying the design target adequately.