This document summarizes the use of fuzzy logic control for pH neutralization processes. It describes how pH neutralization contains nonlinearities due to logarithmic sensor output and changing dynamics from buffer introduction. It presents the schematic of a physical pH control setup and introduces fuzzy logic as an alternative nonlinear controller using heuristic rules. The document outlines simulating a pH neutralization model in MATLAB and designing fuzzy logic components like membership functions and rules. It evaluates controller performance with 9, 15, and 21 rules, finding 21 rules most effectively maintained pH between 7±1. The conclusion recommends fuzzy logic for controlling the highly nonlinear pH process.

1. PH NEUTRALIZATION
PROCESS
BY :
ANKUR MAHAJAN
M.E. I&C (REGULAR)
ROLL NO. 112505

2. PH NEUTRALIZATION PROCESS
 pH neutralization process contain both non-
linearities and changing process dynamics.
 The non linearities are due to the fact that the
output of the pH sensor is proportional to the
logrithmic concentration.
 While the changing process dynamics are brought
out by introducing a buffer into a solution which
significantly alters the response of the system , by
changing the concentration of the control reagents,
and by changing the set point.

3. SCHEMATIC OF THE PHYSICAL PH
CONTROL SET UP
ADC
Card
pH sensor
Input
stream + controller
Buffer
CSTR Acid Base

4. INTRODUCTION TO FUZZY LOGIC
 Fuzzy logic, a relatively new cutting edge technology, is
nowadays gaining popularity.
 Fuzzy control is a practical alternative for a variety of
challenging control applications since it provides a convenient
method for constructing non-linear controllers via the use of
heuristic information.
 With proper design of its components along with a wisely chosen set
of rules, fuzzy control is all set to crack the most complex of control
problems- thanks to Lotfi A. Zedah, who is regarded as the father of
Fuzzy Logic.

5. MODEL FOR NEUTRALIZATION
PROCESS

6. SIMULATION MODEL

7. FUZZY LOGIC TOOLBOX

8. INPUT MEMBERSHIP FUNCTIONS

9. OUTPUT MEMBERSHIP FUNCTION

10. FUZZY RULES FOR CONTROLLER

11. RULE EDITOR IN MATLAB

12. RULE VIEWER AND RESULT OF
DEFUZZIFICATION

13. SURFACE VIEWER

14. SIMULATION OUTPUT WITH 9 RULES

15. SURFACE VIEWER

16. SIMULATION OUTPUT WITH 15 RULES

17. SIMULATION OUTPUT WITH 21 RULES

18. CONCLUSION
 Study of pH neutralization process control has
been carried out successfully using MATLAB.
 It has been demonstrated that fuzzy logic control
performed well to control the highly nonlinear pH
neutralization process within the defined range.
 The results obtained from the 9 rules fuzzy logic
controller is not sufficient to obtain a good pH of
waste water.
 Although 15 rules fuzzy logic controller able to
control the pH of waste water, but 21 rules fuzzy
logic controller is more effectively maintain the pH
of waste water at 7±1.

19. REFERENCES
 S. B. Mohd Noor, W. C. Khor and M. E. Ya’acob, “ Fuzzy logic control of a non
linear pH in waste”, International Journal of Engineering and Technology, Vol.
1, No. 2, 2004, pp. 197 - 205

20. THANKS