Design And Construction Of A Remote Control Gate Using 8051 Microcontroller

 ABSTRACT

This work is titled design and construction of automatic or remote controlled gate. Remote control gate is a technology that involves using remote to control a gate. This device uses remote to control the automatic closing and openning a gate.

A remote-control gate is a handy little electronic device that makes it possible to get into the garage without leaving the car or heaving up the heavy door yourself. The opener remotely sends an infrared or IR signal to a receiver that triggers a switch, prompting an electric motor to open or close the garage door. Before any garage door remote works correctly it must be within the specified range of its IR signal-sending strength. If it is within range but still does not work, there are ways to fix it.

The circuit was designed, and developed using pulse width modulation (PWM) which is generated using 8051 microprocessor. PWM method was used to vary the speed of the DC motor. To make it, IR transmitter and IR sensor was used. There are two sections in the circuit: (1) PWM generator with IR modulator and (2) IR receiver and motor driver.  The transmitter generates PWM wave of 50hz (20ms) and modulates it over 38KHz frequency. The IR sensor on receiver side will demodulate the PWM wave and drives the DC motor.

This work is aimed at constructing a remote control gate using 8051 microprocessor.

CHAPTER ONE

1.0                                                        INTRODUCTION

Remote control gate is a technology that involves using remote to control a gate. This device uses remote to control the closing and opening of a gate automatically.

A remote-control gate is a handy little electronic device that makes it possible to get into the garage without leaving the car or heaving up the heavy door yourself. The opener remotely sends an infrared or IR signal to a receiver that triggers a switch, prompting an electric motor to open or close the garage door. Before any garage door remote works correctly it must be within the specified range of its IR signal-sending strength. If it is within range but still does not work, there are ways to fix it.

The circuit was designed, and developed using pulse width modulation (PWM) which is generated by a microprocessor. PWM method was used to power  the DC motor. To make it, IR transmitter and IR sensor was used. There are two sections in the circuit: (1) PWM generator with IR modulator and (2) IR receiver and motor driver.  The transmitter generates PWM wave of 50hz (20ms) and modulates it over 38KHz frequency. The IR sensor on receiver side will demodulate the PWM wave and drives the DC motor.

The pulse width modulation can be achieved in several ways. In the present project, the PWM generation is done using 8051 series MC. In order to have better speed regulation and the required pulse that will move the motor, it is required to have a feedback from the motor. The feedback can be taken either by using a tacho-generator or an optical encoder or the back EMF itself can be used .In present project, we implemented the feedback by using the EMF of the armature as the feedback signal. Speed control means intentional change of drive speed to a value required for performing the specific work process. This concept of speed control or adjustment should not be taken to include the natural change in speed which occurs due to change in the load on the shaft.

• OBJECTIVE OF THE PROJECT

A remote-control gate is a handy little electronic device that makes it possible to get into the garage without leaving the car or heaving up the heavy door yourself.

The objective of this work is to design a device that will control the closing and opening of a gate automatically using 8051 series MC.

1.2                              SIGNIFICANCE OF THE PROJECT

1. a) Rapid Results – It is quick and easy to configure, giving results in seconds
2. b) Reliability and Ease of Use – It produces high quality results with high repeatability allowing for
3. c) Rapid and reliable decision making
4. d) Rugged and Reliable – It is a circuit with outstanding durability for field use
5. e) Simple User-friendly interface

1.4                                        PURPOSE OF THE PROJECT

The purpose of this project is to build a system that can independently and wirelessly control the opening and closing of a gate. To do this, the system will need 4 core components: an input system for the transmitter, a wireless transmitter, a wireless receiver, and a motor controller connected to the receiver.

1.5                                           LIMITATION OF THE PROJECT

1.if the remote batteries get low it can affect the operation of the system

2. it is not possible to interface keyboard and display.

3 The 8051 microcontroller gulps power and so it heats up.

4. The 8051 microcontroller is not CMOS compatible, only TTL compatible.

CHAPTER TWO

2.0                                                    LITERATURE REVIEW

2.1                                  REVIEW OF TYPES OF GATE OPERATOR

Mechanical

Drawing power from the mains to open a gate. Generally there are four types of electromechanical gate operator: Worm driven (or screw type) swing gates, barrier arm operators and sliding operators Electric and automatic gate openers are designed for both sliding and swinging gates. They can be programmed to open with a manual device or a wireless transmitter. Automatic gate operators can also be fitted with solar panels to operate without high voltage power. Many manufacturers offer battery backup either integrated or as an add on to systems that ensure function during loss of electricity.

Hydraulic

These are used to automatically open an electric driveway gate. As the name implies they use hydraulic fluids to operate their motion. Typically hydraulic operators have less moving parts than mechanical operators. The hydraulic motors have a number of advantages when operating gates; they are capable of producing more power than mechanical motors and do not have to work at full power when operating large gates, they can be made non locking to avoid damage when hit by vehicles relying on other forms of locking. Hydraulic operators are prone to damage to internal seals caused by high pressure from vehicular collision but this damage can be repaired.

2.3                                  REVIEW OF TYPES OF GATE OPERATOR

Swing

Swing gates swing open like the door to your bedroom or bathroom might, simply opening inward or outward.

Swing gates can use three types of operators. A swing arm operator, which is a box, that sits off to the side and has an arm extending to the gate. A ram arm is located on the gate and post and uses either a hydraulic piston or a jackscrew-operated piston. Underground operators are located by the hinge and operate the gate via a link arm.

Slide

As its name implies, a slide gate either slides on wheels from left to right or right to left, not unlike many department store automatic doors.

Slide gate operators are commonly installed at the end of the gate in the closed position but can also be installed by the end of the gate in the open position. In America the most common form of automation is a chain attached across the gate near the bottom and passing through the operator, which shuttles it back and forth. In the end of the gate/open position you do not see the chain or any operating equipment near the gate. In Europe a metal or plastic rack is attached to the gate with a gear fitted to the operator. The American method is more flexible and allows for greater movement in the gates, the European method makes for a quieter and more secure system. Sliding gates are often large, heavy and therefore more hazardous than swing gates they can however be equipped with appropriate safety devices making them some of the safest gate systems available.

Barrier

Barrier gate operators are what you see in parking garages, at toll booths, and at other traffic control areas.

It is an automatic gate consisting of a breakaway gate arm, motor assembly and housing installed at the departure end of a toll island or a car park. A traffic barrier is used to reduce violations and speed through a toll lane. Barrier gates installed in both attended and unattended lanes commonly includes a remote control capability to raise the gate for patrons with insufficient funds.

2.3                             REVIEW OF HISTORY OF REMOTE CONTROL

The earliest example of remote control by radio waves was developed in 1898 by Nikola Tesla and described in his patent, U.S. Patent 613,809, named Method of an Apparatus for Controlling Mechanism of Moving Vehicle or Vehicles. In 1898, he demonstrated a radio-controlled boat to the public during an electrical exhibition at Madison Square Garden. Tesla called his boat a “teleautomaton”.

In 1903, Leonardo Torres Quevedo presented the Telekino at the Paris Academy of Science, accompanied by a brief, and making an experimental demonstration. In the same time he obtained a patent in France, Spain, Great Britain, and the United States. The Telekino consisted of a robot that executed commands transmitted by electromagnetic waves. With the Telekino, Torres-Quevedo laid down modern wireless remote-control operation principles and was a pioneer in the field of remote control. In 1906, in the presence of the king and before a great crowd, Torres successfully demonstrated the invention in the port of Bilbao, guiding a boat from the shore. Later, he would try to apply the Telekino to projectiles and torpedoes, but had to abandon the project for lack of financing.

The first remote-controlled model aeroplane flew in 1932, and the use of remote control technology for military purposes was worked intensively during the Second World War, one result of this being the German Wasserfall missile.

By the late 1930s, several radio manufacturers offered remote controls for some of their higher-end models. Most of these were connected to the set being controlled by wires, but the Philco Mystery Control (1939) was a battery-operated low-frequency radio transmitter, thus making it the first wireless remote control for a consumer electronics device.

Television remote controls

The first remote intended to control a television was developed by Zenith Radio Corporation in 1950. The remote, called “Lazy Bones”, was connected to the television by a wire. A wireless remote control, the “Flashmatic”, was developed in 1955 by Eugene Polley. It worked by shining a beam of light onto a photoelectric cell, but the cell did not distinguish between light from the remote and light from other sources. The Flashmatic also had to be pointed very precisely at the receiver in order to work.

In 1956, Robert Adler developed “Zenith Space Command”, a wireless remote. It was mechanical and used ultrasound to change the channel and volume. When the user pushed a button on the remote control, it clicked and struck a bar, hence the term “clicker”. Each bar emitted a different frequency and circuits in the television detected this sound. The invention of the transistor made possible cheaper electronic remotes that contained a piezoelectric crystal that was fed by an oscillating electric current at a frequency near or above the upper threshold of human hearing, though still audible to dogs. The receiver contained a microphone attached to a circuit that was tuned to the same frequency. Some problems with this method were that the receiver could be triggered accidentally by naturally occurring noises, and some people could hear the piercing ultrasonic signals. There was an incident in which a toy xylophone changed the channels on such sets because some of the overtones from the xylophone matched the remote’s ultrasonic frequency.

The impetus for a more complex type of television remote control came in 1973, with the development of the Ceefax teletext service by the BBC. Most commercial remote controls at that time had a limited number of functions, sometimes as few as three: next channel, previous channel, and volume/off. This type of control did not meet the needs of teletext sets, where pages were identified with three-digit numbers. A remote control to select teletext pages would need buttons for each numeral from zero to nine, as well as other control functions, such as switching from text to picture, and the normal television controls of volume, channel, brightness, colour intensity, etc. Early teletext sets used wired remote controls to select pages, but the continuous use of the remote control required for teletext quickly indicated the need for a wireless device. So BBC engineers began talks with one or two television manufacturers, which led to early prototypes in around 1977–1978 that could control many more functions. ITT was one of the companies and later gave its name to the ITT protocol of infrared communication.

In 1980, a Canadian company, Viewstar, Inc., was formed by engineer Paul Hrivnak and started producing a cable TV converter with an infrared remote control. At the time the most popular remote control was the Starcom of Jerrold (a division of General Instruments) which used 40-kHz sound to change channels. The Viewstar converter was an immediate success, the millionth converter being sold on March 21, 1985, with 1.6 million sold by 1989.

In 2006, Hillcrest Labs introduced the Loop pointer, a remote control that used Hillcrest’s Freespace motion control technology to allow users to control their televisions with natural gestures. The Loop had just four buttons and a scroll wheel. Freespace-enabled remote controls use radio waves to communicate with a USB antenna connected to a computer that is also connected to the television, so they do not need to be pointed at the PC, or even have a direct line of sight.

Some television manufacturers now include Bluetooth remotes to control the television without requiring line of sight, overcoming the limited range in IR-based remotes.

Effect of the early television remote control

The remote allowed audiences, for the first time, to interact with their TV without using the buttons on the TV. They no longer watched programs just because they did not want to get up to change the channel. They could also channel surf during commercials, or turn the sound off.

The invention of the remote control has led to several changes in television programming. One was the creation of split screen credits. According to James Gleick, an NBC research team discovered that when the credits started rolling after a program, 25% of its viewers would change the channel before it was over. Because of this, the NBC 2000 unit invented the “squeeze and tease” which squeezed the credits onto one third of the screen while the final minutes of the broadcast aired simultaneously.

The remote control also led to an adjustment in commercial airings. Networks began to feel that they could not afford to have commercials between programs because it would detract viewers from staying tuned into their channel. Programmers decided to place commercials in the middle of programs to make the transition to the next show direct.

Other remote controls

In the 1980s Steve Wozniak of Apple started a company named CL 9. The purpose of this company was to create a remote control that could operate multiple electronic devices. The CORE unit (Controller Of Remote Equipment) was introduced in the fall of 1987. The advantage to this remote controller was that it could “learn” remote signals from different devices. It had the ability to perform specific or multiple functions at various times with its built-in clock. It was the first remote control that could be linked to a computer and loaded with updated software code as needed.

The CORE unit never made a huge impact on the market. It was much too cumbersome for the average user to program, but it received rave reviews from those who could. These obstacles eventually led to the demise of CL 9, but two of its employees continued the business under the name Celadon. This was one of the first computer-controlled learning remote controls on the market.

The proliferation of remote controls

By the early 2000s, the number of consumer electronic devices in most homes greatly increased, along with the number of remotes to control those devices. According to the Consumer Electronics Association, an average American home has four remotes. To operate a home theater as many as five or six remotes may be required, including one for cable or satellite receiver, VCR or digital video recorder (DVR/PVR), DVD player, TV and audio amplifier. Several of these remotes may need to be used sequentially but, as there are no accepted interface guidelines, the process is increasingly cumbersome.

Many specialists, including Jakob Nielsen, a renowned usability specialist, and Robert Adler, the inventor of the modern remote, note how confusing, unwieldy and frustrating the multiplying remotes have become. Because of this proliferation of remote controls, universal remote controls that manage multiple devices are becoming increasingly popular.

2.4                                DESCRIPTION OF AN ELECTRIC MOTOR

A DC motor is a mechanically commutated electric motor powered from direct current (DC). The stator is stationary in space by definition and therefore the current in the rotor is switched by the commutator to also be stationary in space. This is how the relative angle between the stator and rotor magnetic flux is maintained near 90 degrees, which generates the maximum torque.

DC motors have a rotating armature winding (winding in which a voltage is induced) but non-rotating armature magnetic field and a static field winding (winding that produce the main magnetic flux) or permanent magnet. Different connections of the field and armature winding provide different inherent speed/torque regulation characteristics. The speed of a DC motor can be controlled by changing the voltage applied to the armature.

The introduction of variable resistance in the armature circuit or field circuit allowed speed control. Modern DC motors are often controlled by power electronics systems called DC drives.

The introduction of DC motors to run machinery eliminated the need for local steam or internal combustion engines, and line shaft drive systems. DC motors can operate directly from rechargeable batteries, providing the motive power for the first electric vehicles. Today DC motors are still found in applications as small as toys and disk drives, or in large sizes to operate steel rolling mills and paper machines.

Direct currents (DC) motors have been used in variable speed drives for a long time. The versatile characteristics of dc motors can provide high starting torques which is required for traction drives. Control over a wide speed range, both below and above the rated speed can be very easily achieved. The methods of speed control are simpler and less expensive than those of alternating current motors. There are different techniques available for the speed control of DC motors. The phase control method is widely adopted, but has certain limitations mainly it generates harmonics on the power line and it also has got pf when operated lower speeds. The second method is PWM technique, which has got better advantages over the phase control.

In the proposed project, a DC motor was used to drive the gate from a remote place without any wire connection. The circuit was designed, and developed using pulse width modulation (PWM).

The pulse width modulation can be achieved in several ways. In the present project, the PWM generation is done using 8051. In order to have better speed regulation, it is required to have a feedback from the motor. The feedback can be taken either by using a tacho-generator or an optical encoder or the back EMF itself can be used .In present project, we implemented the feedback by using the EMF of the armature as the feedback signal. Speed control means intentional change of drive speed to a value required for performing the specific work process. This concept of speed control or adjustment should not be taken to include the natural change in speed which occurs due to change in the load on the shaft.

2.5                                       APPLICATIONS OF ELECTRIC MOTOR

Every electric motor has to have some sort of controller. The motor controller will have differing features and complexity depending on the task that the motor will be performing.

The simplest case is a switch to connect a motor to a power source, such as in small appliances or power tools. The switch may be manually operated or may be a relay or contactor connected to some form of sensor to automatically start and stop the motor. The switch may have several positions to select different connections of the motor. This may allow reduced-voltage starting of the motor, reversing control or selection of multiple speeds. Overload and over current protection may be omitted in very small motor controllers, which rely on the supplying circuit to have over current protection. Small motors may have built-in overload devices to automatically open the circuit on overload. Larger motors have a protective overload relay or temperature sensing relay included in the controller and fuses or circuit breakers for over current protection. An automatic motor controller may also include limit switches or other devices to protect the driven machinery.

More complex motor controllers may be used to accurately control the speed and torque of the connected motor (or motors) and may be part of closed loop control systems for precise positioning of a driven machine. For example, a numerically controlled lathe will accurately position the cutting tool according to a preprogrammed profile and compensate for varying load conditions and perturbing forces to maintain tool position.

2.6                                                TYPES OF MOTOR CONTROLLERS

Motor controllers can be manually, remotely or automatically operated. They may include only the means for starting and stopping the motor or they may include other functions.

An electric motor controller can be classified by the type of motor it is to drive such as permanent magnet, servo, series, separately excited, and alternating current.

A motor controller is connected to a power source such as a battery pack or power supply, and control circuitry in the form of analog or digital input signals.