i need a seminar report for pH control using fuzzy logic on the basis of matlab and detailed informaion of fuzzy controller system for pH.
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Diffuse control is a practical alternative for a variety of challenging control applications as it provides a convenient method for constructing nonlinear controllers by using heuristic information. Since heuristic information can come from an operator that has acted as a "loop" controller for a process. In the fuzzy control design methodology, a set of rules on how to control the process is annotated and then incorporated into a fuzzy controller that emulates the decision-making process of the human being. In other cases, heuristic information may come from a control engineer who has done extensive mathematical modeling, analysis and development of control algorithms for a particular process. The rest of the process is the same as in the previous case. The ultimate goal of using fuzzy control is to provide an easy-to-use formalism to represent and implement ideas we have about how to achieve high-performance control. Aside from being a widely used technology these days, diffuse logic control is simple, efficient and efficient. In this work, the structure, operation and design of a fuzzy controller is discussed in detail through an in-depth analysis of the development and operation of a fuzzy logic pH controller.
PH Control
To illustrate the application of fuzzy logic, the remaining section of paper is directed toward the design and operation of a pH control system using fuzzy logic. PH is an important variable in the field of production especially in chemical plants, sugar industries, etc. PH of a solution is defined as the negative of the logarithm of the hydrogen ion concentration, to the base 10. Ie, PH = -log 10 [H +]. Consider the stages of operation of a sugar industry, where PH control is required. The main concern is the clarification of the raw juice of the sugar cane. The raw juice will have a pH of 5.1 to 5.5. The clarified juice ideally should be neutral. That is, the set point must be a pH of 7. The process involves the addition of lime and SO2 gas to clarify the raw juice. The addition of these two is called lime and sulphitation, respectively. Since the process involves the continuous addition of lime and SO2; Lime has the property of increasing the pH of the clarified juice. This is the principle used for the control of PH in the sugar industries. The pH of the raw juice is measured and this value is compared to the set point and this is further used to change the diameter of the lime flow tube according to the requirement.
The whole process can be summarized as follows. The PH sensor measures the PH. This reading is amplified and recorded. The output of the amplifier is also fed to the PH indicator and to the interface. The output of this block is fed to the fuzzy controller. The output of the fuzzy controller is given to the motor drive step by step. This inturn adjusts the diameter of the lime flow tube according to the requirement. Therefore, the input to the fuzzy controller is the PH reading of the raw juice. The output of the diffuse controller is the diameter of the lime flow tube valve or an amount that controls the diameter of the lime flow pipe valve as a direct current, voltage, and so on. The output obtained from the fuzzy controller is used to drive a Motor step which inturn controls the diameter opening of the value of the lime flow tube. This production tends to maintain the pH value of the sugar juice at a target value. The following section provides a detailed description of the design and operation of the fuzzy controller.