CHAPTER ONE
1.0 INTRODUCTION
An
elevator is a type of vertical
transport equipment that efficiently moves people or goods between floors
(levels, decks) of a building, vessel or other structures. Elevators are
generally powered by electric motors that either drive traction cables or
counterweight s like a hoist, or pump hydraulic fluid to raise a cylindrical
piston like a jack. In agriculture and manufacturing, an elevator is any type
of conveyor device used to lift materials in a continuous stream into bins or
silos. Several types exist, such as the chain and bucket elevator, grain auger
screw conveyor using the principle of Archimedes' screw, or the chain and
paddles/forks of hay elevators. The elevator was a key invention in the development of
skyscrapers. Up to that point, it was considered that no building should be
higher than 10 storeys because of the effort of climbing and descending the
stairs. The elevator is also a means which reduces time to transfer the things
very quickly from one stairs to another. With the population growing the need
for housing is increasing with the lack of livable area, housing as increased
into multi level units, thus the need for elevators. They provide access for
those who are handicapped. Having an apartment on the 12th floor, walking the
stairs can be a challenge, making an elevator is a bonus because you don't have
to walk up and down the stairs. It allowed the people to travel up and down the
building so much easier that it allowed for taller and taller buildings to be
made, which allowed more square feet of office space, business space, etc
The
elevator system is a vertical transport vehicle that efficiently moves people
or goods between floors of a building. They are generally powered by electric
motors. The most popular elevator is the rope elevator. In the rope elevator,
the car is raised and lowered by transaction with steel rope. Elevators also
have electromagnetic brakes that engage, when the car comes to a stop. The
electromagnetic actually keeps the brakes in the open position. Instead of
closing them with the design, the brakes will automatically clamp shut if the
elevator loses power. Elevators also have Automatic braking systems near the
top and the bottom of the elevator shaft.
The
elevator control system is one of the most important aspects in electronics
control system in automotive applications in the world today due to level of
the introduction of high rising building in architectural constructions worldwide.
In this investigation elevator control system is designed with different
control strategies. First the elevator control system is implemented for
multi-storey building with five storeys rising. This implementation is based on
Fuzzy logic controller for intelligent control of elevator group system. This
proposed approach is based on algorithm which is developed to reduce the amount
of computation required by focusing only on relevant rules and ignoring those
which are irrelevant to the condition for better performance of the group of
elevator system. Here only two inputs are considered i.e. the elevator switches
and number of stops. Based on these data, fuzzy controller can calculate the
Performance Index (PI) of each elevator car, the car which has maximum PI gives
the answer to the hall calls (Varun Dubey p.221, 2005).
The
elevator control system that is implemented in this project is designed around
the 8051 microcontroller unit which performs all the necessary calculations
that are required for the operation of the elevator in the building that it is
installed. The control also provides a seven segment display system with which
the position of the lift is noticed. The project also provides a motor control
system that controls the movement of the elevator up and down the building.
In
the operation of the system, When a User presses an elevator button; the
elevator button sensor sends the elevator button request to the system MCU
(microcontroller unit) of the project, identifying the destination floor the
user wishes to visit. When any new request comes, this new request is added to
the list of floors to visit. If the elevator is stationary, the system
determines in which direction the system should move in order to service the
next request. The system commands the elevator door to close, when user presses
the elevator door closed button. When the door has closed, the system commands
the motor to start moving the elevator, either in up and down direction, based
on switch pressed. When the elevator moves between floors, the arrival sensor
detects that the elevator is approaching a floor and notifies the system to
stop the elevator and open the door of the elevator system. The movement of the
elevator is controlled by the motor control (Maxda.F p56, 1984).
The
project implementation is achieved through the use of the 8051 microcontroller
unit which is used to perform all the necessary calculations that is required
for the system operation. The project also makes use of a seven segment display
unit for the display of the various positions of the lift in the building. Also
present, is the motor driver unit which simply controls the movement of the
motor in order to lift the elevator up and down the building.
1.1 BACKGROUND OF THE STUDY
The
trend to the modern types of elevators has pass through series of evolutionary
changes. The first reference elevator was invented by Archimedes in 312. From
some literacy source, elevators were developed as cable on a hemp rope and
powered by hand or by through animals. This type of elevator was installed in
the Sinai Monastery of Egypt. In the 17th century, the very small type
elevators were placed in the building of England and France. In 1793, Lvan
Kuliben created an elevator with the screw lifting mechanism for the winter
place of Saint Petersburg. In 1816, an elevator was established in the main
building of Sub-moscow village called Arkhamgelskoye. In the middle 1800’s,
there was much type of curd elevators that carried freight. Most of them ran
hydraulically. The first hydraulic elevators used a plunger below the car to
raise or lower the elevator. A pump applied water pressure to a plunger, or
steel column, inside a vertical cylinder. In 1852, Elisha Otis introduced the
safety elevator, which prevented the fall of the cab, if the cable broke. In
1857 March 23rd, the first Otis passenger elevator was installed in New York
City. The first Electric elevator was built by Werner Von Siemens in 1880. In
1874, J.W. Meaker patented a method which permitted elevator doors to open and
close safely. In 1882, when hydraulic power was a well established technology,
a company later named the London Hydraulic Power Company was formed. In 1929,
Clarence Conrad Crispen, with Inclinator Company of America, created the first
residential elevator (Varun Dubey p.221, 2005).
The
elevator modeled in this project works with the principles of the electric
motor elevators. The movement of the elevator is controlled by the movement of
the electric motor that is used in the project. The control of the elevator is
achieved by the use of the microcontroller unit that utilizes the principles of
artificial intelligence.
1.2 AIM OF RESEARCH
The aim of this project
is to design a system that will transport people and goods to different levels
in a five story building. Due to technological advancements, in the world,
automation of system has dominated most systems in the world utilizing the
principles of artificial intelligence to enable systems behave as though they
are humans and act with mimic of the human life. The concept of the elevator lift
is an invention that enables the movement of people and cargo up and down a
given building, enabling the movement to be facilitated with much ease. The
need for such achievement is the main goal of this project. The project is
aimed at implementing a reliable control system of the elevator in a given
building by the use of the 8051 microcontroller unit
1.3 OBJECTIVES
The
project is also designed with the following objectives;
v
To design a lift control system by using
microcontroller 8051
v
To design the program (software) for the
overall system according to the real lift traffic management algorithm
v
To integrate the hardware and software
in order to simulate the functions of a basic lift system.
v To
build a lift model to simulate the actual system.
v To
investigate various other existing systems and employ some improvements and
modifications that makes the system more reliable.
1.4 MOTIVATION
In
the recent times, the rate of construction of high rising buildings, multi-stories
and sky scrapers has risen to a great extent. For this reason there is a need
to provide a reliable method by which human beings and goods can be moved up
and down the high rising structures. The implementation of this project is
carried out with the aim of providing such system that can enable the movement
of people as well as goods up and down a given structure irrespective of the
height and size.
1.5 SIGNIFICANCE OF THE STUDY
The elevator was a key invention in
the development of skyscrapers. Up to that point, it was considered that no
building should be higher than 10 storeys because of the effort of climbing and
descending the stairs. The elevator is also a means which reduces time to
transfer the things very quickly from one stairs to another. With the
population growing, the need for housing is increasing with the lack of livable
area, housing as increased into multi level units, thus the need for elevators.
They provide access for those who are handicapped. Having an apartment on the
12th floor, walking the stairs can be a challenge, making an elevator is a
bonus because you don't have to walk up and down the stairs. It allowed the
people travel up and down the building so much easier that it allowed for
taller and taller buildings to be made, which allowed more square feet of office
space, business space, etc
1.6 SCOPE AND LIMITATIONS OF THE RESEARCH
The five storey’s elevator control
system that is implemented in this project is a well reliable system that
offers application for a wide range of areas including domestic buildings and
industrial buildings. The project focuses its attention on the implementation
of lift control for a five storeys structure. It is only actually a model that
is used for the demonstration of the real time system. Thus for the proper
implementation of the project, it is required that the design should be
reproached for a real time application basis. The project is also limited to a
number of factors and these includes;
À It
only lays emphasis on the implementation of five storeys building structure and
does not include the design for more complex building structures.
À The
project is subject to a very high cost of installation and maintenance.
À The
implementation of the project is quite complex to achieve.
À The
integration of the soft ware and the hard ware is quite difficult to implement
and requires an extra knowledge of the designer for its maintenance.
À The
project is also completely dependent on power supplies and can lead to great
complications if power supply failure occurs.
CHAPTER TWO
2.0
LITERATURE
REVIEW
2.1 INTRODUCTION
The elevator was a key invention in the development of
skyscrapers. Up to that point, it was considered that no building should be
higher than 10 storeys because of the effort of climbing and descending the
stairs. Many buildings today are completely dependent on the elevators for the
movement of things up and down the building. The trend to the
mother types of elevators has pass through series of evolutionary changes.
2.2 HISTORY OF ELEVATOR
Elevators
began as simple rope or chain hoists. An elevator is essentially a platform
that is either pulled or pushed up by a mechanical means. A modern day elevator
consists of a cab (also called a "cage" or "car") mounted
on a platform within an enclosed space called a shaft or more correctly a hoist
way. In the past, elevator rive mechanisms were powered by steam and water
hydraulic pistons. (Wikipedia, 2 August 2005)
During
the middle ages, the elevator operated by animal and human power or by
water-driven mechanisms. The elevator as we know it today was first developed
during the 1800s and relied on steam or hydraulic plungers for lifting
capability. In the latter application, the cab was affixed to a hollow plunger
that lowered into an underground cylinder. Liquid, most commonly water, was
injected into the cylinder to create pressure and make the plunger elevate the
cab, which would simply lower by gravity as the water was removed. Valves
governing the water flow were manipulated by passengers using ropes running
through the cab, a system later enhanced with the
Incorporation
of lever controls and pilot valves to regulate cab speed. The granddaddy of
today's traction elevators first appeared during the 19th century in the United
Kingdom, a lift using a rope running through a pulley and a counterweight
tracking along the shaft wall. (Elevator Info, 1992)
In
the 1800s, with the advent of electricity, the electric motor was integrated
into elevator technology by German inventor Werner von Siemens. With the motor
mounted at the bottom of the cab, this design employed a gearing scheme to
climb shaft walls fitted with racks. By 1903, this design had evolved into the
gearless traction electric elevator, allowing hundred-plus storey buildings to
become possible and forever changing the urban landscape. Multi-speed motors
replaced the original single-speed models to help with landing-leveling and
smoother overall operation. Electromagnet technology replaced manual
rope-driven switching and braking. Besides, Push-button controls and various
complex signal systems modernized the elevator even further. Safety
improvements have been continual, including a notable development by Charles
Otis (Charles Otis, 1996).Today, there are intricate governors and switching
schemes to carefully control cab speeds in any situation. Buttons have been
giving way to keypads. Virtually all commercial elevators operate automatically
and the computer age has brought the microchip-based capability to operate vast
banks of elevators with precise scheduling, maximized efficiency and extreme
safety. Elevators have become a medium of architectural expression as
compelling as the buildings, in which they are installed, and new technologies
and designs regularly allow the human spirit. (Elevator Info, 1992).
2.3 THE OVERVIEW OF THE 8051 MICROCONTROLLERS
FAMILY
The
8048 Microcontrollers were predominant in the early 1960’s and 1970’s and
served as the main chip for embedded programs
until in 1980 when INTEL introduced
the 8051. INTEL made sure that the transmission from the already
successful model was as smooth as possible. The extensions on the 8048 to 8051
include code and data memory extended to 64km, with appropriate support in
instruction sets and registers (DPTR), and the inclusion of relative
conditional and unconditional jumps as well as four registers bank instead of
two unlimited stack, multiple and divided instructions and additional second
timer, with both extended to 16bits with multiple (including 8-bit auto reload
mode) and an UART (a luxury that many lower end Microcontroller’s do not have).
The 8051 family has for these numerous advantages, gained grounds over other
Microcontrollers (Mazidi, Mazidi, and Rolin 2000).
A
microcontroller can be extensively compared to a standalone small computer; it
is a very powerful device, which is capable of executing a series of
pre-programmed tasks and interacting with other hardware devices. Packed in a
tiny integrated circuit (IC) whose size and weight is usually very negligible,
it is becoming the perfect controller for Robots or any machine requiring some
kind of intelligent automation. Any microcontroller contains a memory to store
the program to be executed, and a number of input/output lines that can be used
to interact with other devices, like reading the state of a sensor or
controlling a motor. Microcontrollers are indispensable tools for the Robotic
Hobbyist as well as for the engineer (Wikipedia.com).
The
choice of the 8051 series of microcontrollers in the implementation of the
elevator lift control in this project is due to their special feature which
includes;
- 64KB
on chip program memory
- 128
bytes on chip data memory (RAM)
- 4
register banks
- 128
user defined software flags
- 8
– bit data bus.
- 16
– bit address bus.
- 32
general purpose registers each are 8 bits
- 16bit
timers (usually 2, but many have more or less).
- 3
internal and 2 external interrupts
- Bit
and byte addressable RAM area 16 bytes
- Four
8-bit ports, (Short models have two 8 – bits ports)
- 16
– bit program counter and data pointer
- I
Microsecond instruction cycle with 12 MHz crystal.
- Built
in UART (universal Asynchronous receiver transmitter) is serial communication.
(Wikipedia.Com).
2.4 REVIEW
OF THE PROJECT
There
exists a number of ways in which the implementation of a lift/elevator control
can be implemented in a given society. The method used for the implementation
of this project was chosen because of the simplicity of the design techniques
and the reliability of the technique. In the operation of the system, When User
presses an elevator button; the elevator button sensor sends the elevator
button request to the system MCU (microcontroller unit) of the project,
identifying the destination floor the user wishes to visit. When any new request
comes, this new request is added to the list of floors to visit. If the
elevator is stationary, the system determines in which direction the system
should move in order to service the next request. The system commands the
elevator door to close, when user presses the elevator door closed button. When
the door has closed, the system commands the motor to start moving the
elevator, either in up and down direction, based on switch pressed. When the
elevator moves between floors, the arrival sensor detects that the elevator is
approaching a floor and notifies the system to stop the elevator and open the
door of the elevator system. The movement of the elevator is controlled by the
motor control.
The
project implementation is achieved through the use of the 8051 microcontroller
unit which is used to perform all the necessary calculations that is required
for the system operation. The project also makes use of a seven segment display
unit for the display of the various positions of the lift in the building. Also
present, is the motor driver unit which simply controls the movement of the
motor in order to lift the elevator up and down the building.
REQUEST FOR PROJECT MATERIAL
Good Day Sir/Ma,
WARNINGS!
PLEASE make
sure your project topic or related topic is found on this website and
that you have preview the abstract or chapter one before making payment.
Thanks for your interest in the research
topic. The complete research work will cost you N2000 and we will send
the material to you within 24hours after confirming your payment.
Make the payment of N2000 into any of the account
number below and we will send the complete material to you within
24hours after confirming your payment.
Account Name: Agada Leonard E
Account No: 2070537235
Bank: UBA
Account No: 2070537235
Bank: UBA
Or
Account Name: Agada Leonard E
Account No: 3049262877
Bank: First Bank
Account No: 3049262877
Bank: First Bank
Or
Account Name: Agada Leonard
Account No: 0081241151
Bank: Diamond Bank
Account Name: Agada Leonard
Account No: 0081241151
Bank: Diamond Bank
After payment, send the following information to us through this email
address: enemsly@gmail.com
Topic paid for:
Amount Paid:
Date of Payment:
Teller No or Transaction ID:
Name of Depositor:
Depositor Phone Number:
Email address:
NOTE: The material will be forwarded to the email address you provided
within 24hrs after confirmation of the payment.
Thanks.
Agada Leonard E.
For: Enems Project.
For more information visit our contact page @ CONTACT US
No comments:
Post a Comment