Modeling,Simulation And Implementation Of The PH Neutralization Process Plant Using An Intelligent Controller

The use of advanced control techniques in process industries has become more challenging over the past few decades.This can be attributed to problems such as complexity of processes,consumers’requirements in high quality products,advancements in technology as well as stringent environmental rules among others.In order to overcome all the aforementioned challenges,process industries must use reliable,precise,robust,proficient and flexible control systems for the operation of their process plants;for not only this is so important for the smooth operation of their process plants but it is also important for plants upgrades and technology adaptations.Therefore,there is an enduring effort to improve the forms of control systems and their subsequent process models in order to meet all the requirements and promote a smoother operation of their systems control loops.It is to none surprise that advanced control technology has a direct and yet remarkable impact on the overall industrial control engineering.In fact,most of the recent studies indicate that there is an ever increasing utilization of advanced form of controllers often referred to as intelligent controllers.These are the types of controllers which in their operation imitate/replicate most of the important characteristics of the people’s way of thinking while making decision to solve social problems and/or uncertain processes.Controllers which are able of accomplishing all the above mentioned are those designed using Fuzzy Logic and Neural Networks platforms.The present study focuses a number of objectives which include the design and implementation of an intelligent/advanced controller for a pH neutralization process.This controller is based on Fuzzy Logic algorithm and features self-adaptive structures.The first feature of this study concerns the conception,design and implementation of an industrial pH neutralization process plant.The system is conceived and built in the Control Systems Lab of the College of Mechanical and Electronic Engineering-Fujian Agriculture and Forestry University.One of the most interesting advantages of this plant is that it uses all the instrumentation and materials such as those used in a typical industrial pH neutralization process plant.This helped to identify most the problems that are known to process industries when it comes to pH neutralization process and an attempt was envisaged to solve those relating to control systems,model development and process plant design and implementation.A full scale mechanical PH system is designed and all components and platforms(hardware and software)needed for the completion of the plant are highlighted.The second aspect of this research work deals with the establishment of an accurate mathematical model representing the developed pH neutralization process.The aforementioned model is then used to develop an intelligent type of controller based on both the Fuzzy Logic and self-adaptive algorithms.One of the key achievements of this section of the work is that all the results obtained from the developed plant dynamic model have been compared in details with the experimental results obtained from the pH process plant itself and after all due assessments and investigation the model has been deemed to be suitable and acceptable for the intended application/design.The third and last part of this work involves the implementation and testing of self-adaptive fuzzy logic controller(intelligent controller)for the developed pH neutralization plant.This controller uses the feedback control structure which allows it to react to all the unmeasured disturbances occurring during the control action,hence achieving greater control results.Although some may argue that this type of control structure has been reported in literature for quite a long time,it is also true that most of the studies available in the literature have always been using either a bench top type of system/laboratory scale or simulations alone to investigate the performance of this type of control structure when used for this kind of process.This obviously leaves a big room for studies featuring full scale system as they get to deal with all of the control problems that real industrial systems do face.A self-adaptive fuzzy logic controller configured with a feedback control algorithm was developed and a reasonable range of tests and experiments were successfully carried out on both the Matlab based simulation environment and the real time pH process.A comparison between results obtained from these tests indicate that results from the real time pH plant are largely similar to results obtained from simulation.As such,it is hoped that methods used and results obtained from this study may contribute in some way to closing all the gaps between theory and practice when it comes to pH neutralization or similar nonlinear processes.