Essay: Home automation systems

Home appliances (like audio/video devices and communication equipment) and air condition systems (heating and cooling) require high energy consumption, therefore making our homes one among the foremost essential areas for the impact of energy consumption on natural surroundings. This project aims for the planning and design of a system which will minimize energy in home environments with efficiency managing devices. In our design we use a wireless sensing element to observe physical parameters (like light-weight and temperature). All these monitoring and control operations can be achieved without necessarily requiring someone to be at home. The sensors take inputs from the environment and sends it to the microcontroller which in turn performs the operation of turning on/off the light and regulate the fan speed. The light sensor will automatically turn on the light after sensing total darkness in the environment by taking inputs from the environment and sending it to the microcontroller which then will perform the desired operation while the temperature sensor after taking input from the environment will send it to the microcontroller to perform the operation of regulating the fan speed.
CHAPTER 1
INTRODUCTION
1.1 OVERVIEW OF PROJECT
With the fast development in technology, home automation provides a more convenient & elegant atmosphere for the family to compliment and match the lifestyle [12]. Members of the family enjoys the comfort of automation with added convenience through the automatic control of light and fan in the environment. Energy efficient smart home automation system using temperature sensor and light sensor (LM35 and LDR) respectively provides a reliable and effective way of managing electric power and providing security to the family. The temperature sensor LM35 measures the temperature of the room automatically and sends the result as an input to the microcontroller to perform the task of regulating the temperature of the room through the help of the relays, and also the light sensor LDR is used to measure the light intensity of the room and provides an input to the microcontroller which then performs the operation of turning on/off the light. This system tends to enhance home and lifestyle. It also provides safety of equipment (light bulb and fan) which now operate precisely as per recommendations, it gives convenience and comfort as well as energy bills reduction. The sensors are used in few projects to provide many features ranging from efficient use of energy to increased comfort, greater safety and security.
1.2 PROBLEM STATEMENT
Research conducted into pre-existing home automation systems while preparing our literature review revealed that almost all existing home automation systems use a direct current (DC) fan this can be improved further because a DC operated automation system has the following disadvantages small in size and has a variable uneven speed compared to an AC operated system. Our project seeks to eliminate these problems by designing an automation system capable of full functionality using alternating current (AC).
Most existing solutions lack certain significant features. The focus here is on addressing most of the problems associated with existing solutions in home security and smart systems.
Other examples of problems in most home automation systems are listed below.
1. Most existing systems are not affordable for most users due to high costs and difficult maintenance.
2. Some systems provide solutions that are not very useful for household applications.
3. Some current systems provide a view of the house from a web application; however, this can inconvenience the user, who must access the Web each time the user wishes to view the status of the house.
1.3 MOTIVATION
The term smart home has always seem like an unrealistic paradise; having lights that turn on and off depending on the light intensity of the environment, fan that activates when the temperature is too high, entire home changing its form at specific hours or when presence is detected. People think it’s a future unrealistic perfect home but these kind of devices have been in the market for ages and people have been building their ideal perfect home. The question then is why is it a future topic? Probably because of how hidden and expensive these devices are in the market, people thinking that it is only meant for the rich and therefore cannot be afforded in their homes. Also, their lack of knowledge in this technology and how they will benefit from it.
Therefore, the motivation behind the development of this system is to let people know about these technologies, and make the system as simple as possible for an ordinary person to understand; letting them know of the full benefits home automation provides them.
1.4 OBJECTIVE OF PROJECT
The objective of this project is to implement a low cost, reliable and efficient home automation system that will be able to stand the test of time without affecting its functionality. The system will be able to automatically switch on or off the lights in the home environment and also regulate the fan using light and temperature sensors respectively that takes input from the environments and sends it to the atmega328 microcontroller.
1.5 ORGANISATION OF REPORT
This document provides background information and describes the tools used to build the home automation system. The entire report for this project has been arranged into five main chapters described as follows:
Chapter one starts with an introduction to the entire project, the problem statements, motivation and objectives of the project.
Chapter two takes us through the literature review of related works from automation to the types of automation down to the home automation standards.
Chapter three is based on the system design, brief description of the existing system, proposed system and the system requirements both software and hardware.
Chapter four has to do with the testing and evaluation of the system and its performance.
Chapter five concludes the report and states future and further enhancements on the system which were not achieved due to some factors.
CHAPTER 2
LITERATURE REVIEW
2.1 INTRODUCTION TO AUTOMATION
Since the invention of the first automated device in the year 1898, it will be interesting to see how far people have come in terms of technology, as it is ever changing and moving forward. The first automated system which is a wireless remote control was unveiled by Nikola Tesla in the year 1898 which he used to steer a miniature boat using radio waves. In 1901, engine powered vacuum cleaner was created after which electric powered vacuum was made six years later. Over the next two decades huge strides would be made with domestic appliances which include: refrigerators, washing machines, clothing dryers, irons and toasters. However, only the rich could afford them in their homes.
In the 1930s when the ideas of home automation came to mind and was discussed but nothing was physically invented. But in the year 1966 “Echo iv” was created by Jim Sutherland. It was the first home automation system that would control temperature, turn appliances on and off and even make a shopping list but unfortunately this system was not sold commercially. In the year 1969, the Honeywell kitchen computer was created to help in creating recipes but it was too expensive, therefore had no commercial success. But in the year 1971 the microcontroller/microprocessor was invented causing huge price reduction in technology (a good thing for the home automation industry). The term smart home was first used by American Association of House Builders in 1984.
In 1990s there was a great focus on technology and gerontology to be used in improving the lives of the elderly and the weak. Domotics were also becoming more prevalent; this is where computers and robots are combined with domestic appliances. But unfortunately the technology up to the end of the century was still very expensive and not accessible to the masses. The integer millennium house that was later renamed the smart home after being refurbished in 2013 is a demonstration house in Watford, England that opened to the public in the year 1998 to showcase home automation in its finest, therefore making technology cheaper and more efficient and accessible.
Whereas home automation used to seem like something out of a fiction that only the rich can afford, today it is everywhere. Allowing us to control our homes with the tip of our fingers to our smart phones and tablet. While home automation is really taking off today but we still have a long way to go. The good thing is that the possibilities of this technology are endless. Through simulation one can optimize the efficiency of smart home automation system but nowadays mostly VB (visual basic) and PLCC is being used. Practically we can implement the smart home by many researchers to optimize the better result and to improve the technology for the less consumption of electricity.
2.2 AUTOMATION
Automation or automatic control is the use of various control systems for operating equipment such as machinery, processes in factories, boilers and heating ovens, switching on telephone networks, steering and stabilization of ships, aircraft and other applications with minimal or reduced human intervention. The biggest benefits of automation is that it saves labor, it also saves energy and materials and to improve quality, accuracy and precision. The term automation was not widely used before 1947, when General motors established the automation department. It was during this time that industry was rapidly adopting feedback controllers which were introduced in 1930. Automation has been achieved by various means including mechanical, hydraulic, pneumatic, electrical, electronic devices and computer usually in combination.
Types of automation ranges from ordinary discrete control (on/off) which is normally used for household appliances. It provides provision for the on/off of appliances such as thermostats, and for variable fan speed control. The second type which is the continuous control uses feedback control that is continuous and makes use of a sensor and also we have the open and closed loop that is been controlled by a controller.
Automation provides us with a variety of advantages such as increased throughput or productivity of systems, improved quality of devices, increased consistence of systems, reduced direct human labor cost and expenses ,it also improves economy because if a country invests in automation, technology recovers its investment, it also reduces operation time and work handling time significantly, frees up workers to take on other jobs, provides higher level jobs in the development, maintenance and running of the automated processes etc.
2.3 TYPES OF AUTOMATION
2.3.1 OFFICE AUTOMATION
Office automation refers to the varied computer machinery and software used to digitally create, collect, store, manipulate and relay office information needed for accomplishing basic office tasks. Raw data storage, electronic transfer and the management of electronic business information comprise the basic activities of an office automation system. Office automation helps in optimizing existing office procedure. The back bone of office automation is a local area network (LAN), which allows users to transfer data, mail or even voice across a network. It makes it possible for office tasks to be accomplished faster, it eliminate the need for large staff etc.
2.3.2 BUILDING AUTOMATION
Building automation is the automatic centralized control of a buildings heating, ventilation and air conditioning, lighting and other systems through a building management system or building automation system (BAS). The objectives of building automation is to improve occupant comfort, efficient operation of building systems, and reduction in energy consumption and operating cost. It works in the form of a distributed control system. BAS main functionality is to keep building climate within a specified range, provides light to rooms based on occupant schedule ( in the absence of over switches to the contrary), monitors device failures and performance in all systems and also provides malfunction alarms to building maintenance staff. The BAS reduces building energy and maintenance costs compared to a non-controlled building
2.3.3 POWER AUTOMATION
Power automation is the automatic control and monitoring of power system which includes processes associated with generation and delivery of power. It makes it possible to monitor different units and relay their status and health information and also carry out fault detection and correction without human interference. An example of a power automation system is the supervisory control data acquisition (SCADA) system that operates with codded signals over communication channels so as to provide control of remote equipment (using typically one communication channel per remote station).
2.3.4 HOME AUTOMATION
A home automation is an extension of building automation that involves the automation of housework or household activities. Providing an automated home for the weak and elderly tends to improve the quality of life of that person. It involves the control of domestic activities that includes the control of entertainment systems, house plant and yard watering, lighting control system and the use of domestic robots.
A home automation system integrates all the electrical devices in the house with each other, it includes centralized control of lighting, HVAC(Heat, ventilation and air conditioning) appliances, security locks and other systems to improve comfort, conveniences, security and energy efficiency. Imagine after working so late at night and coming home to be welcomed at the door by lights illuminating from your room without touching any light switch. The level of security and comfort you will feel will be unimaginable and also being able to have your fan being regulated automatically depending on the current weather condition. Home automation provides us with what is often referred to as a “smart home”, a home that will be able to identify and recognize you, that can automatically regulate the light to your preferred taste, automatically open your door and tune in to your favorite radio station, switch on the lights for security reasons. It makes it possible to link lighting, entertainment, security, telecommunications and air conditioning to a centralized system.
The number of houses that make use of an automated system that ranges from automated security lock, automated air conditioning system that helps in maintaining a predefined temperature to a burglar alarm has been in a rapid rise since its inception.
2.3.4.1 HOME AUTOMATION SYSTEMS
Home automation systems in home and residential buildings provides electronic systems that make possible the automation of household appliances. The new stream of home automation has developed into a vast one and the current market is flooded with a variety of home automation systems and device manufacturers.
The types of home automation systems based on their control systems are:
1. Individual control systems
This is the first type of home automation system to hit the market. Here, each devices will have an independent control dedicated to it.
2. Distributed control systems
This is used for emergency shutdown. With this you can be able to change or preset the parameters of several similar devices and their on/off timing separately.
3. Central control systems
These are computerized systems programed to handle all functions of multiple utilities like air conditioning systems, home entertainment, doors, windows, refrigerators and cooking systems all at the same time regardless of whether you are at home or not. You connect to the control systems through telephone or internet from anywhere in the world.
The types of home automation systems based on their carrier mode are:
1. Powerline carrier systems
The less expensive type of home automation system operates over the home existing wiring or powerline carrier. These can range from X10 based lamp timers, to more sophisticated systems that require installation by a trained professional.
2. Wireless systems
Also available are wireless home automation systems that utilize radio frequency technology. They are often used to operate lights, sometimes in conjunction with a hardwired lighting control system.
3. Hardwired system
Wired or hardwired home control system are the most reliable and expensive. This systems can operate over high-grade communications cable such as category 5e, or their own proprietary “bus” cable. That is why it is best to plan for them when a house is being constructed. Hardwired systems can perform more tasks at a time and do them quickly and reliably, making them ideal for larger homes. They can also integrate more systems in the home, effectively tying together indoor and outdoor lighting, audio and video equipment, security systems even heating and cooling system into one control package that will be easy and intuitive to operate.
4. Internet protocol control system
Internet protocol (IP) control automation system makes use of the internet, gives each device under its control an internet protocol address and creates a local area network (LAN) in the home. Hence the home can be interacted with over the internet with the possibility of live video streaming and real time control.
2.3.4.2 HOME AUTOMATION STANDARDS
. Security alarm interfaces and sensors,
. Home sensors (e.g. water, humidity, temperature, light)
. Access control (e.g. door locks),
. Heating, ventilating and air cooling (HVAC) control,
. Audio video control, and
. Appliance management.
CHAPTER 3
SYSTEM DESIGN
3.1 EXISTING SYSTEM
Currently automated homes are mainly for the rich because of its high prices. Therefore for an individual to enjoy the comfort that today’s home automation systems bring to the environment, he or she has to be rich or come from a rich family resulting in the rich becoming richer and the poor remaining poor because of constant waste of electrical energy by the poor.
Also, these systems has limitations in implementation using an alternating current (AC) fan because of its inability to control the speed of the AC fans using relays. Therefore, it is used for only direct current (DC) fans which have a variable, uneven flow of speed and they are usually small in size. Unlike the AC fans, the DC fans cannot power a whole room because of its size.
A typical DC fan requires a transformer because its current flows in only one direction and so cannot be connected directly to a DC power source such as solar plants or batteries. That means that while using a DC fan, one must use a transformer to convert AC to DC so that the fan can be powered.
Also, the existing home automation systems using light sensors are basically used for both the outside light and bedroom light which also results in energy waste because while one is not at home, the room light will still be on which will consume power. With the DC fan, one will not be able to regulate the speed of the fan using relays.
3.2 PROPOSED SYSTEM
The design of this system provides detailed functions, interfaces and working output to give a clear and understandable view of the system to enable team members to communicate with each other and ease client understanding of the overall working of the project.
With unified process, the detailed design explains the circuit working of each of the hardware component by the designing team. That is, how each hardware interact with one another to form an independent unit to ease the task of the programing team. The working of the sensors and how they interact with the environment and the microcontroller.
In this project, we are developing a system that can be able to implement an alternating current (AC) fan and regulate its speed automatically depending on the room temperature using the relays with constant even flow speed. We are using four relays for the regulation of the fan speed ranging from 20 which is the minimum to 100 which is the maximum speed that runs between temperature ranges. It provides an even and constant speed at every temperature range unlike the DC fans which are variable. Since the AC fans are big in size, it provides an added advantage in terms of powering the whole room unlike the DC fans which are small in size and only suitable for small rooms.
Also in this project, the light sensor is only used for the outside environment in order to help reduce power consumption.
3.3 SOFTWARE REQUIREMENT
1) Arduino version 1.6.5
3.4 HARDWARE REQUIREMENT
1) Arduino ATmega328 Microcontroller
2) LM35 Temperature sensor
3) Light dependent resistor (LDR)
4) LCD display (16*2)
5) Relays
6) Power supply
3.5 DESIGN DEVELOPMENT PROCESS
3.5.1 CIRCUIT DIAGRAM
The circuit diagram is the graphical representation of an electrical circuit. It shows the components and the inter connections of the circuit using standardized symbolic representations. The circuit diagram shows the actual electrical connections.
DETAILED DESIGN
3.6.1 LM35 TEMPERATURE SENSOR
LM35 IC is used to measure the temperature of a room. Temperature sensor LM35 is a precision IC with its output voltage proportional to the measured temperature level of the room in degree Celsius. The LM35 temperature sensor provides high accuracy than a thermistor for measuring temperature. Also compared to the thermocouple, the output voltage level of LM35 temperature sensor is in an accurate high voltage level, there is no need of output voltage amplifiers.
3.6.1.1 FEATURES OF LM35 TEMPERATURE SENSOR
1) Operating temperature range: -550 degree Celsius to 1500 degree Celsius.
2) Low Impedance output.
3) Self-heating is very low.
4) Low cost.
5) Not affected by oxidation and any other process.
When the LM35 takes input from the environment, the controller then compares the room temperature measured by the LM35 with a predefined value and according to that, the controller will control the fan.
3.6.2 LDR (LIGHT DEPENDENT RESISTOR) OR PHOTORESISTOR
LDR is a light controlled variable resistor. The resistance of the LDR will vary in accordance with the incident light intensity. The resistance of the LDR will decrease with increase in the light intensity that incident on the photoresistor. In this project the LDR is used to detect the light intensity level of the environment and gives signals or output to the microcontroller and according to the readings from the LDR, the microcontroller controls the operations like, switch on and off the light.
3.6.2.1 Advantages of LDR
1) LDR’s are cheap and are readily available in many sizes and shapes.
2) They need very small power and voltage for its operation.
3.6.2.2 Disadvantages of LDR
1) Highly inaccurate with response time of about tens or hundreds of milliseconds.
2) Using an LDR in the real world.
3.6.3 ARDUINO PLATFORM
Arduino is one of the famous electronic devices in the world due to being open source, flexible software and hardware. The Arduino platform is a simple device built in the AT-mega Microcontroller. Moreover, the software for Arduino works with many operating systems, such as Mac, Windows and Linux. Therefore, the Arduino is better than many types of Microcontroller. The Arduino software language is based on C. There are many types of Arduino modules available on the market. There are a variety of the number of ports and type of Microcontroller along with many purposes for the Arduino.
1) The software and hardware are free and open source, very flexible and easy to expand.
2) It includes a variety of analog and digital ports, such as I2C, SPI serial interface.
3) It is easy to use and connects to a computer through a USB port.
4) It is cheap and comes with free software and IDE environment.
5) It is bundled with copious amounts of ready-to-use source code.
The Arduino platform is a great tool for developing interactive objects. It receives input from outside, for example, sensors and switches and then controls lights, doors or other outputs. The Arduino platform works as a stand-alone device or connects to a PC through a USB port. Therefore, the Arduino platform can be used in projects requiring serial communication [8].
3.6.3.1 Arduino Hardware
The Arduino hardware board is a Microcontroller board, which is a small circuit that consists of many electronic components. The Arduino board is a whole computer on a small chip. There are many types of Arduino hardware available on the market. These may vary in size, use, the number of ports and type of Microprocessor. Examples of these types of Arduino hardware include Arduino Nano, Arduino Mega, Arduino Mini, Arduino Galileo and Arduino UNO. The Arduino name is a registered trademark, so it is not possible to name a cloned board Arduino. In this project, we made use of the ATMEGA328 Arduino UNO microcontroller [8].
3.6.3.1.1 ATMEGA328
ATMEGA328 is a single chip microcontroller created by Atmel and belongs to the megaAVR series commonly used in projects and autonomous systems where a simple, low powered, low cost microcontroller is needed.
The ATMEL 8bit AVR RISC based microcontroller combines 32KB ISP flash memory with read and write capabilities, 1KB EEPROM, 2KB SRAM, 23 general purpose working registers, three flexible timer/counter with compare modes, internal and external interrupts, serial programmable USART, a byte oriented 2 serial wire interface, SPI serial port, 10bit A/D converter (8 channels in TQFP and QFN/MLF packages), programmable watchdog timer with internal oscillator and five software selectable power saving modes. The device operates between 1.8-5.5 volts.
KEY PARAMETERS:
PARAMETERS VALUES
FLASH 32 KBYTES
RAM 2 KBYTES
PIN COUNT 28
MAX. OPERATING FREQUENCY 20MHZ
CPU 8BIT AVR
# OF TOUCH CHANNELS 16
HARDWARE QTOUCH ACQUISITION NO
MAX I/O PINS 26
EXT INTERRUPTS 24
USB INTERFACE NO
USB SPEED NO
Table (1): Atmega328 parameters
The output from the ATMEGA328 Microcontroller is given to the fan and light controlling relays. According to the microcontroller output the corresponding actions will be carried out.
3.6.3.2 Arduino Software
The other part of the Arduino platform is the Arduino Integrated Development Environment (IDE). This software comes with the Arduino or can be downloaded at no cost from the Arduino site. This software is built in Java. With this software, we can edit, write sketches and upload code to the Arduino. The basis of this software is the C- language. This software is set up in the computer. This compiler is open source.
A first step in the IDE checks whether the C or C++ code is correct. After checking whether the code is correct, the IDE passes the code to a compiler (avr-gcc) to change it from human readable to machine readable instructions. Then, the code is combined with the Arduino libraries code, which provides a basic function. The result of this process is a single hex file. This file contains the specific bytes and it is ready to write to the program memory on the Arduino board, which is transmitted to the Arduino over a USB port or serial connection [8].
Fig (3): Arduino IDE environment
3.6.4 FAN AND LIGHT CONTROLLING RELAYS
SPDT relay is the type of relay used in this project. This RELAY module is suitable for office machine, domestic appliance, automobile, audio etc. These Relays act as a circuit switch according to certain switching condition. Also the Relay offers a high protection to the electrical appliances. According to the output from the microcontroller, the relay controls the fan and light. Relay is among the most important electromagnetic devices highly used in industrial application specifically in automation. It is use for electronic to electrical interfacing. It is used to switch on or off electrical circuits operating at high AC voltage using a low DC control voltage. It has two parts; a coil which operates at the rated DC voltage and a mechanical movable switch. The electronic and electrical circuits are electrically isolated but magnetically connected to each other, hence any fault on the other side does not affect the other side.
3.6.5 POWER SUPPLY
In this project an IC 7805 regulator is used for supplying power to the entire circuit. 7805 regulator IC is a voltage regulator integrated IC 78xx series. Because there will be a lot of functions going on in the main supply voltage therefore causing damage to the entire circuit.
The voltage regulator IC 7805 used here protects the entire circuit from these voltage fluctuations by filtering the voltage variations and providing a constant output voltage to the entire home automation system. The 7805 regulator IC provides a +5 voltage of regulated power supply. Filtering capacitors are used along with the IC’s respective pins with respect to the voltage levels.
CHAPTER 4
TESTING AND EVALUATION
4.1 TESTING
This chapter explains the testing and evaluation of the system and how it works. In this system we used two sensors namely LM35 temperature sensor to detect heat and LDR to observe the light intensity of the environment, an AC motor fan and light bulb as the load for the temperature and light sensors respectively, one LCD for the display of both sensor readings. Also five relays were used; four of them is for the regulation of the fan speed (that is, each relay is defining its own speed) ranging from 20% for relay 1; 40% for relay 2; 80% for relay 3 and 100% for relay 4 while the last relay is for the light.
The system consists of Arduino atmega328 microcontroller, LCD, relays, light and temperature sensor, transformer, fan regulator, AC motor fan, transistor and a light bulb all of which are connected to the microcontroller. The testing process was carried out by team members to ensure that the system is working perfectly by varying the temperature sensed by the temperature sensor using a soldering iron to increase the temperature and an ice cream to reduce the temperature. The results obtained were noted and recorded at every temperature range. After the testing to ensure that the temperature sensor LM35 is working perfectly with the Arduino atmega328. The light sensor LDR was also tested by allowing the sensor to sense the darkness and put on the light bulb which was carried out perfectly.