Fuzzy pid based Temperature Control of Electric Furnace for Glass Tempering Process

1.2 Statement of the problem 
In thermal tempering glass production process the task temperature control is the main part 
and it has an important influence on the quality of the products. Therefore, to produce 
tempered glass with a high quality, temperature in the glass tempering furnace must be 
controlled very well. Inadequate temperature control in the tempering furnace will lead to 
some product defects. Thus, in order to successfully control the temperature in the tempered 
furnace, the glass must be heated to a given temperature (tampering temperature) quickly. In 
addition, the temperature difference between the various parts of the glass surface must be 
very small, i.e., the glass surface must be heated evenly. 
In the tempered glass furnace industry, the widely used controller for temperature control is 
the conventional PI and PID controllers which are not robust haven’t good dynamic response, 
long rise time and large overshoot are used to control the temperature. Also fuzzy logic 
controller which introduces steady state error in the system is used. In chemical tempering 
method, various chemicals exchange ions on the surface of the glass in order to create 
compression [1][2]. But because of its higher cost when compared to the tempering method 
using furnaces and quenching, chemical tempering is not widely used. 
Therefore, in this thesis, fuzzy PID controller is proposed. The fuzzy PID controller will avoid 
the above problems because it mixes advantage of fuzzy and conventional PID controllers. 
1.3 Relevance and scope of the Thesis 
To have good understanding the use of fuzzy PID controllers in controlling nonlinear activities 
like electric furnace. And to Study and design temperature controller for glass tempering and 
propose implementable design for the future in order to produce cost effective and good 
quality glass. 

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Fuzzy PID Based Temperature Control of Electric Furnace for Glass Tempering Process
M.Sc. Thesis, Addis Ababa University, December 2016 
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