Design & Manufacturing an Inclined Elevator

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Design Manufacturing an Inclined Elevator
United Arab Emirates University College of
Engineering

• Ali Hussain 200000240
• Mohammed Obaid 200000297
• Habib Al-Saffar 200000318

Project Advisor Prof. Kamal Moustafa
Second Semester 2005/2006
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Outline

• Introduction
• Objectives
• Mechanical system
• Control system
• Results and discussion
• Conclusion

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Introduction

• An elevator is a transporting device used to move
  goods or people vertically, horizontally or
  inclined.
• Inclined elevators are used in such places that
  can not use vertical space or used by disabled
  persons that can not use an escalator.

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Objectives

• GPI
• Carrying out complete dynamic force analysis.
• Applying engineering sciences.
• Designing elevator components such as brakes,
  roping system, buffers etc.
• GPII
• Selecting proper components according to the
  design analysis.
• Building a prototype with control devices.

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Mechanical System

• Counterweight
• Selection of suspension rope
• Traction drive
• Elevator machine

• Car
• Door
• Guiding rails

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Real Design Layout
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Scaling

• Scaling can be defined as the determination of
  the interdependency of variables in a physical
  system.
• Advantage
• Used in solving cost effective problems.
• A model was made with same geometric, kinematics
  and dynamic similarities as the real design.
• The selected scaling factor was 100088.

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2D AutoCAD drawings
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Cont.
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Cont. (Cabin)
Cabin mass 1.13 Kg
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Cont. (Counter-weight)
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3D AutoCAD drawing
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Prototype pictures
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Motor recalculation
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Control System

• Objectives
• Controlling DC motor (Up, Down).
• Controlling motor acceleration deceleration.
• Controlling level stops.
• Operating system accessories (fan, light and
  door-lock).

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Closed-loop control diagram
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Sensor

• Rotary optical encoder
• It is a digital electronic device used to convert
  the angular position of a shaft to a number of
  pulses.
• 256 pulses.
• The input voltage is 5 volts.

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Cont.
Coupling
Sensor
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Control device

• Microcontroller unit (MCU)
• Defined as a computer on a chip which is used to
  control electronic devices.
• Advantages
• A microcontroller unit can be a powerful tool
  when building electro-mechanical systems.
• It interacts with both hardware and user.

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Atmega8 (MCU(

• 8-Kbyte self-programming Flash.
• Two timers.
• 28 Input and Output Pins.
• Input voltage between 4.5 to 5.5 V.
• Output current is equal to 40 mA.
• Operating at 4 MHz frequency.

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Atmega8 (MCU( Pins Diagram
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Actuator

• Motor speed control
• A PWM technique works by making a pulsating DC
  square wave with a variable on-to-off ratio.

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Duty cycle

• The duty cycle of the pulses exiting the MCU was
  calculated as following

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Motor direction controller

• How does a motor turn in two directions ?
• By two ways
• Manually.
• Automatically by a computer or a microprocessor.

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Bipolar junction circuit

• H-bridge technique has four switching elements at
  its corners and the motor forms the cross bar.

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Cont.
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Relay H-Bridge
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Relay operation

• A current flows through the coil, the resulting
  magnetic field attracts the armature.
• The movement either makes or breaks a connection
  with a fixed contact.
• When the current to the coil is switched off, the
  armature is returned to the first position.
• At the switching off action, the collapsing
  magnetic field will generate a spike of current
  that could damage the rest of the circuit.

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Single Pole Double Throw (SPDT)

• Used to reduce the number of relays from four to
  two.
• Two relays with 20A current each were used.

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Circuit components

• Opto-coupler
• An opto-coupler is an optical link and it
  connects two circuits via this link.
• Used as insulation and a switch for any circuit.

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Cont.

• Transistor array
• Used to increase the current level in order to
  operate the relays (amplifier).
• MOSFET power transistor
• Supplies 110 A current to the motor.

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Cont.

• Crystal filter
• It provides a very exactly defined centre
  frequency which leads to stabilize the input
  frequency.
• Supply frequency equals to 4 MHz.
• Voltage regulator
• Automatically maintains a constant voltage level
• Supplies 5 V after changing it from 12 V.

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Cont.

• And Gate
• A logic gate is an arrangement of controlled
  switches used to calculate operations in digital
  circuits.
• It is a multiplication operation between the
  three input variables (A,B and D).

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Cont.

• Diode
• It allows an electrical current to flow in one
  direction.
• Seven-segment display
• A method of displaying decimal numeric feedback
  on the internal operations of devices.

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Printed circuit board (PCB)

• Used to mechanically support and electrically
  connect electronic components using conductive
  pathways made from copper sheets on a
  non-coductive material.
• PCBs are inexpensive, fast, and consistent in
  high volume production.

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Power supplying and direction schematic
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Power supplying and direction circuit
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MCU schematic
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MCU circuit
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Complete control system circuit
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BASIC COMPILER
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Cont
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Cont
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Results Discussion

• Cycle period

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Cont.
Acceleration operation
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Cont.

• The obtained frequency from the oscilloscope was
  equal to 1.9 KHz.
• The percentage error between the theoretical and
  experimental values was equal to 5.

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Cont.

• The velocity of the cabin was measured
  experimentally after the acceleration and before
  the deceleration operation periods.

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Cont.

• The percentage error of velocity was equal to
  13.
• This error was formed by two factors
• The slip between the rope and the sheave groove.
• Random error.

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Conclusion

• All objectives of the project were met.
• Modifying the project can be done by two ways
• Adding limit-switch at each floor.
• Enhancing the sheave contact area with the rope
  (V-groove).