Design Of The Controller Of Furnace Burning System Using C8051F020

Furnace burning system is a multivariable system. The process of burning has obvious non-linear characteristics. Its variable controlled time varies greatly, and it can be effected by many factors, intersection strongly, out disturbance frequently. It is very hard to set a nicety applied mathematics model for this system. Because fuzzy controller doesn't need to build the model of the object controlled, it has certain adaptability for the nonlinearity and time-variety of the object controlled. Therefore, we select fuzzy control algorithm as the control algorithm of the furnace burning system.In this paper, we have designed a controller applied to furnace control especially, using high speed SOC microcontroller and its peripheral interface circuits. It can realize blowing the hearth automatically, detecting the natural gas automatically, firing automatically. It also can adapt fuzzy control algorithm to control the furnace burning system when it runs normally. During the period of designing the algorithm of fuzzy control, I chose a method of fuzzy-PID composite control firstly. When error is in a given confine, it will be set in PID control. On the contrary, it will be set in fuzzy control when the error is out of the given confine. The conversion is realized automatically by the program which is set the given confine beforehand. It has a better control effect through simulation. But it is hard to describe a question of a practical project using membership function in fuzzy control. It is used interval-valued fuzzy sets rather than general fuzzy sets to describe the certainty of a certain membership for the given fuzzy concept. So it does fit practicality than general fuzzy sets in complex control system in fact. Moreover, we proposes an average factor in the process of approximate reasoning based on interval-valued fuzzy sets in a double-input-single-output approximate reasoning scheme in this paper. The method proposed can simplify the process of operation and quicken the pace of reasoning. Furthermore, because the proposed method requires only simple arithmetic operations, it can be easily programmed and applied to reality.C8051F020 of company Cygnal acts as a core in the hardware of this controller. We selected SHARP 5.7 inches LCD with touch screen as the displayer of the controller. The controller has 8 channels 12-bit A/D input, 8 channels D/I (non-power node), 8 channels D/O (SSR output) 220V AC 5A, 2 channels D/A 4~20mA output. Because we selected small-outline package components, the whole size of the controller is very small.The software is edited by C51 language, which adopts fuzzy control technology to realize the automatic control of the furnace burning system. It was used JTAG interface to download the program to the FLASH memory of C8051F020.