Undergraduate Student, College of Engineering and Computer Studies

Transcription

1 Design and Development of a Fuzzy Logic Based - Digital Regulated DC Power Supply with an Automatic Reverse Polarity Using Arduino Microcontroller Ma. Ramona A. Alcantara 1, Guia Daniella L. Lanting 1, Ralph Laurence G. Visaya 2* 1 Undergraduate Student, College of Engineering and Computer Studies 2 Graduate Student, College of Engineering and Computer Studies Lyceum of the Philippines University- Laguna *Corrresponding Author: sayaviarvie@gmail.com Abstract: In this world s growing technology, people used gadgets everyday like cellphones, laptops and different kinds of recent technologies. Most of them need power supplies. Power supplies play a greater role in the present day, in school, in industry, in households in everyday lives. This research study presents the improvisation of normal power supply used today. This Fuzzy Logic microcontroller based digital regulated dc power supply with automatic reversing of polarity is ranging from 0-24 Volts with a maximum current output current of 1 Ampere. The proponents also make a fuzzy logic algorithim for the fuzzy logic tuning and test and experiment the functionality of the sensors needed. The proponents also make use of the Matlab Fuzzy Logic Toolbox for the Fuzzy Logic simulation and Arduino IDE for the programming platform of the Arduino. The Sugeno style of fuzzy inference system was used in the system. Triangular membership functions were used in the control system. Two Fuzzy inputs are constructed namely: the error, and change in error. The proponents also constructed FAM matrix for the rules in the fuzzy logic. The output of the fuzzy logic is normalized in the Dev C++ for fine tuning and getting the accurate and precise outputs. The relay module serves as the switch for the automatic reversing of the polarity of the circuit. It also uses the current sensor for sensing the deflection of the current when a circuit is connected in wrong polarity. The proponents used the experimentations to validate the functionality and applicability of the designed and developed and it was verified experimentally that the results obtained by the proponents were acceptable. Key Words: Fuzzy Logic; Matlab; Sugeno; Arduino; polarity; 1. INTRODUCTION This section of research intends to clarify and explain the workings of the research study. It includes the statement of the problem, the objectives and the scope and limitations. This part required to measure the feasibility of the research 1.1 Background of the Study Nowadays, vast majority of electronic devices are powered by DC power source, so it requires a reliable, consistent and modified power supply. Generally, the requirements are not excessively differed, but still they oblige every time a new hardware designing. The idea presented here is to construct a digitally controlled regulated power supply with auto polarity corrector that is sufficiently adaptable to meet the researchers objectives and expectations, with minor programming changes and no corresponding hardware change. Hardware issues are discussed, with an objective of innovating a simple power supply that has programmable output voltage and current. It is capable of recognizing faults and takes corrective actions to prevent any permanent damage to the entire system. The system conversed here is capable of operating independently by its own without any intervention from the user. The system discovers application at remote sites to automatically manage primary (AC) and secondary (battery) power sources to provide smooth uninterrupted power output even during conversion between AC and DC power sources. The

2 vast majority of this equipment requires DC voltage as well as voltage that are well filtered and controlled. Since power supplies are broadly used as electronic equipment, those devices now contain an overall section of the electronic market. The trend and demand these days are to build up systems that are dependable and intelligent. It has to be consistent enough not to damage what is hooked up to. 1.2 Statement of the Problem Nowadays, electrical power supply is one of the most important elements in human being needs. Most of human activities depend on the demand of electrical power supply. Electronic lab experiments frequently need a power supply to perform such activity. And in this high technology world, it is normal for people to possess gadgets which powered by its battery. In using a DC power supply, many students got confused whether the experiment needs a positive or a negative supply. Because of this confusion, this may results in damaging what is attached to it. Based on this problem, this project is the answer wherein it has the ability to correct its polarity without interchanging the probes once it is hooked up to the equipment, same thing with the battery charging. Since this project aims to develop a power supply consisting of a DC supply and charging a battery, it is the solution. 1.3 Objectives of the Study The main objective of the study is to construct a fuzzy logic based digital DC power supply with automatic reversing of the polarity which prevents damage of the components when connected in reverse polarity. Specifically, the proponents are wanted to create a program that will incorporate the fuzzy logic into the microcontroller and to create a program that will reverse the polarity of the power supply. Assemble a digital DC power supply where the user can input the voltage through buttons. The proponents also test and evaluate the functionality of the different electronic modules compatible with Arduino like relay module, voltage sensor, and current sensor. 2. METHODOLOGY 2.1 Project Description The Digital DC Power Supply with Auto- Polarity Corrector is a device which supplies DC voltage and can charge batteries. This is a microcontroller based power supply which is developed concerning to make an intelligent device and flexible enough to meet different requirements to eliminate the restrictions of the existing systems. This is an improved power supply made up of AC to DC converter as main component with an output ranges from 0 to 17 volts and can charge batteries. It has the ability to recognize faults and take corrective actions to prevent any permanent damage to the system. Being an automatic polarity correcting power supply, it also works disregarding the polarity of the circuit being hooked up and the polarity of the connected battery. At the center of the whole system is the microcontroller. Microcontroller is embedded inside the device so that it can control the features and actions of the device. It is small and low cost. The components are chosen to minimize size and to be as inexpensive as possible. Necessary amplification is provided. To enable it to read the analog signals, an Analog to Digital converter is used. It has a digital display showing the actual measurement values of the output voltage of the power supply. The hardware design is flexible and can be easily scaled to the requirements. 2.2 Arduino IDE This project is a software controlled microcontroller based system, which makes it intelligent, independent of operator supervision and can adapt to a restricted set of changed requirements without any hardware change. The software for this project was developed using a simple high level language in C++. It also used ARDUINO IDE sketchbook for PC to system interface. The software controls the input display of the device and manipulates its polarity depending on the parameters of the equipment engaged through it. The Arduino IDE is an opensource Arduino Software it provides an easy way to write a code and upload it to the board, it runs on Windows, Mac OS X, and Linux. The environment is written based on Processing, Java, and other open-source software s. The software can be used with any Arduino board. 2.3 Fuzzy Logic Controller The first step in designing Fuzzy Logic System is to describe fuzzy sets, the information in terms of fuzzy linguistic terms or can be regarded as values equal to 0 or 1 and values within them. The fuzzy membership function is used to assign values with respect to fuzzy sets and its degrees of membership. Moreover, the most commonly used technique requiring four parameters to be specified with respect to its x and y coordinates is called Trapezoidal Membership Function. Also, the Triangular Membership Function can be used in

3 the system which requires three parameter specifications. 2.4 System Flowchart indication to relay. The output of the relay will be the starting point of Automatic reversing polarity circuit dependent on the signal from current sensor. The output will be displayed in the LCD. And a LED will indicate if the power supply is acting normally or reversing. 3. DESIGN CONSIDERATION 3.1 Hardware Connection Fig. 1. System Flowchart of the System In the figure 1 above, the user inputs the desired voltage through buttons. After that the output will be displayed to the LCD. If there is deflection in the current sensor, this will automatically start polarity reverse, after that report the result of the data and display the output. If there is no deflection, report the data to the arduino then send the data to be displayed in the LCD display. 2.5 Hardware Block Diagram Fig. 3. Hardware Connection In figure 3, it shows the electronic connection of the system. The proponents used the ATMEGA 2560 Arduino microcontroller as the main controller of the system. Buttons serve as the main input for the voltage of the power supply. The current sensor and the voltage sensor will send signal to the arduino and the LCD will display the readings from the voltage and current. When the current sensor senses any deflection in the current when connected to a wrong polarity. It will send signal to relay that will trigger as the switch of polarity. 3.2 Fuzzy Logic Simulations Fig. 2. Hardware Block Diagram In the figure 2, the source comes from the power supply which is the main source of the system. The output the supply will be connected to a voltage sensor and the current that will give signal to microcontroller. That signal will be fuzzified and the output of the fuzzy logic will be fed to the microcontroller. The Arduino will send In this part, the proponents used the MATLAB Fuzzy Logic Toolbox in the simulation of the Fuzzy System of the software part of the system. The proponents used the Sugeno Style Fuzzy Interference system and the novelty of this study is the fine tuning of the crisp output of the system. Rules are constructed with 16 weights in the system. Sugeno was used because of simplicity and output of this method is linear unlike to the output of Mamdani. The fuzzy logic is applied to the current sensor to provide smooth readings of the current.

4 a. It is compatible to Arduino (ATMEGA 2560) an advantage over other current sensors. b. It does not require any external supply. c. It can detect high/ current that help to achieve the objective which the auto reversing polarity. d. The sensor circuitry is sealed and not complicated. Fig 4. Fuzzy Logic Input with Membership Function Fig 6. The Current Sensor (ACS712) B. Voltage Sensor The voltage sensor is composed of two resistors in a voltage divider configuration. The proponents used this to display the input voltage in the LCD display via buttons. The Arduino analog input is limited to a 5 VDC input. It is fundamentally a voltage divider using a 100K and a 10K Ohm resistor. Fig. 5. Fuzzy Logic Output Given in the figures above 4 and 5, it show the input and the output of the fuzzy logic simulations. The proponents used the triangular membership functions with parameters in the input error and change in error NB, NS, Z, PB. Triangular membership function used because it is the best for beginners and easy to understand. Sugeno style fuzzy logic interference has been used also as the interference system in the automatic polarity supply. 3.3 System Sensors A. Current Sensor The proponents used the sensor ACS712 that provides economical and precise results for DC current sensing in electrical and electronic systems. Typical applications include motor control, load detection and management, switched- mode power supplies, and over current fault protection. The proponents made use of the ACS 712 sensor because of the following: Fig. 7. Voltage Sensor 3.4 System Application Almost all analog power converters are least efficient even in light loads. Also, there are times that people apply the power supply to an electronic load with wrong polarity that leads to the device failure or malfunction. The researchers used the microcontroller for improving the analog power supply to digital and including an additional feature of auto- polarity corrector. The system has an automatic response particularly in case of wrong terminal connections. It will automatically switch the polarity once the microcontroller detects current deflection. The system also has the fuzzy logic which gives more precise and accurate time response of the reversing of the polarity. The fuzzy logic applied to the current sensor which gives smooth reading of

5 the current and when there is deflection of current. Thus, this will give the signal to the relay in changing the polarity with the shortest time possible though the deflection of the current. One application of this research is this can be used in different electronic loads especially in complex circuits and it is one of the recommendations of the one of the research literatures. Also, it can be used in schools, industries, in homes or in any places where power supplies are needed to be used. Table 2. Time Response of the Different Test Samples 4. EXPERIMENTS AND ANALYSIS OF RESULTS This part is to show the analysis and interpretation of data for series of experiments. The proponents record the voltages displayed on the LCD and input voltages measured by a digital tester with its percentage error. Table 1. Values for the Percent Error of the Voltages In the table 2, the proponents used stopwatch in a smartphone to measure the time when the circuit is connected in a normal polarity and the time when the circuit is connected in a reverse polarity. As cited in the table, the time of test sample 1 in normal condition is 12ms and the other sample is 20ms. In the revese condition, the time is ranging from 0.80ms to 0.93ms. Fig 8. Graphical Representation of Time Response of Water level Circuit It shows in the table 1 the values measured and displayed voltages with the computed percentage error. It is shown that from the results obtained in the figure, it can be observed that the percentage error has low value so which means that the voltage output of the power supply is reliable and accurate and stable which provides clear view of accurate voltage output Fig 9. Graphical Representation of Time Response of FM Radio

6 In the figures 8 and 9, it shows the graph of the time response of each test samples. It is shown in the figure that the maximum time is 0.94ms and the minimum time is 0.82ms. Thus, this made clearly that the time will reduce the circuitry to break because of the sensitivity when connected to a wrong polarity. Table 3. Calculation of the Correlation Coefficient 6. ACKNOWLEDGEMENT First and foremost, the researchers would like to thank the Name of the Lord Jesus Christ for the understanding, wisdom and knowledge that he gave. The proponents also would like to thank Engr. Ralph Laurence Visaya as our adviser and mentor for his support and for his perpetual help in times of needs and troubles. This research is not feasible without the cooperation of everyone. 7. FUTURE RECOMMENDATIONS The researchers want to recommend for the future researchers to use a different microcontroller board like Raspberry Pi. Also, make use of the keypad for the input voltage so that the user can pick numbers to input voltage output. If ever possible adjust the maximum voltage to higher voltages. 8. REFERENCE In the table shown, it shows the calculation of the correlation coefficient of the time response of the reverse polarity of the two samples. In the result, there is a Perfect Correlation between the time responses of the two batteries. In correlation coefficient -1 and 1 are values that are in perfect correlation and in the results in the table, the value reaches CONCLUSION Based on the data gathered and the experiments, the result was favorable. Analyzing the tables 1 on the experiment, it is evident that the displayed voltage of the power supply using button as input is almost equal to the measured voltage because as seen it has low percentage error, which satisfies the accuracy of the output voltage. Besides, it is also suitable to be used because of its short time response. The Fuzzy Based Power supply responds in a very least possible time. Thus, the time response is strong and almost near to the normal time response of the system when the connection is in normal condition. The research is properly and accurately working which satisfied the objectives of this study, which satisfied the objectives of this study. The time reponse meets from 0.80 to 0.94 sec which is not destructive when it comes to circuitry thus, this make the research accurate. Jamolod, Emerson, Visaya, Ralph Laurence G. and et al. (October 2015). Development of a Digital Regulated DC Power Supply with an Auto- Polarity Corrector Using Arduino Microcontroller. Mustafa R Abuzeid, Ramadan AElmoude, Nasr E Shtawa. (April 12-14, 2007.) A novel Strategy for Synchronizing of Two DC Motors: Al-azhar Engineering Ninth International Conference. Jitender Kaushal. (June 2012). Comparative Performance Study of ACO & ABC Optimization based PID Controller Tuning for Speed Control of DC Motor Drives. Bin Adzmi K.A. (4 November, 2008).Motor Speed Controller Using Fuzzy Logic Method for PCB Drilling Operation,. S.Z. He. S. Tan, F.L.Xu. (1993). ''Fuzzy self-tuning of PID controllers, fuzzy set and Systems.