Design And Construction Of A Proximity Detection Sensor

ABSTRACT

Proximity sensor detects the presence of nearby objects without any physical contact. Examples of proximity sensor usage include detecting an out-of-paper condition in a printer or a mobile phone screen that dims to save battery life when placed near a face.

Proximity sensor often emits an electromagnetic field or a beam of electromagnetic radiation (infrared, for instance), and looks for changes in the field or return signal. The object being sensed is often referred to as the proximity sensor’s target.

Proximity Sensors are analog output reflective sensors in a small form factor SMT package that offer a distance detection range near zero to 60mm.

Their operating principle is based on a high frequency oscillator that creates a field in the close surroundings of the sensing surface. The presence of a metallic object (inductive) or any material (capacitive) in the operating area causes a change of the oscillation amplitude. The rise or fall of such oscillation is identified by a threshold circuit that changes the output state of the sensor. The operating distance of the sensor depends on the actuator’s shape and size and is strictly linked to the nature of the material.

TABLE OF CONTENT

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION
  • OBJECTIVE OF THE PROJECT
  • SIGNIFICANCE OF THE PROJECT
  • APPLICATION OF THE PROJECT
  • PROJECT SCOPE
  • ADVANTAGES OF THE PROJECT
  • PROJECT ORGANISATION

CHAPTER TWO

• LITERATURE REVIEW
  • REVIEW OF PROXIMITY SENSOR
  • HISTORITICAL BACKGROUND OF PROXIMITY DETECTOR
  • REVIEW OF DIFFERENT TYPES OF PROXIMITY SENSOR
  • REVIEW OF IR TECHNOLOGIES FOR PROXIMITY SENSING

CHAPTER THREE

• CONSTRUCTION
  • BLOCK DIAGRAM
  • PROXIMITY SENSOR CIRCUIT SCHEMATIC
  • SYSTEM OPERATION
  • CIRCUIT DESCRIPTION
  • DESCRIPTION OF COMPONENTS USED

CHAPTER FOUR

• RESULT ANALYSIS
  • INSTALLATION OF THE COMPLETED DESIGN
  • CONSTRUCTION PROCEDURE AND TESTING
  • CASING AND PACKAGING
  • ASSEMBLING OF SECTIONS
  • TESTING OF SYSTEM OPERATION
  • PROBLEM ENCOUNTERED
  • COST ANALYSIS

CHAPTER FIVE

5.1      CONCLUSION

5.2      REFERENCES

CHAPTER ONE

1.0                                                        INTRODUCTION

Proximity Detection Sensors detect and measure reflected infrared (IR) energy to detect the presence of an object or person.  The proximity detection devices offer a wide range of performance, with four programmable LED drive currents and IR pulse repetitions. The proximity detection circuitry compensates for ambient light, allowing it to operate in environments ranging from bright sunlight to dark rooms. The wide dynamic range allows operation in short-distance detection applications behind dark glass, such as cell phones. Proximity Detection Sensors can be used for a mechanical switch replacement or to sense human gesturing.

Proximity sensors detect the presence or absence of an object. Examples of proximity sensor usage include detecting an out-of-paper condition in a printer or a mobile phone screen that dims to save battery life when placed near a face.

Proximity Sensors are analog output reflective sensors in a small form factor SMT package that offer a distance detection range near zero to 60mm.

Proximity sensors can be used in industrial, automotive and consumer applications.

• OBJECTIVE OF THE PROJECT

The objective of this work is constructing a device which can be used to detect the presence of nearby objects without any physical contact. That  does this by emitting an electromagnetic field or a beam of electromagnetic radiation (infrared, for instance), and looks for changes in the field or return signal.

• SIGNIFICANCE OF THE PROJECT

As a student of electrical/electronics engineering, this work has exposed me to know the application and description of many electronics components. It also made me to know that an object can be detected by electromagnetic field without making any physical contact with the object.

   1.3                                      APPLICATIONS OF THE PROJECT

• Parking sensors, systems mounted on car bumpers that sense distance to nearby cars for parking
• Ground proximity warning system for aviation safety
• Vibration measurements of rotating shafts in machinery
• Top dead centre (TDC)/camshaft sensor in reciprocating engines.
• Sheet breaks sensing in paper machine.
• Anti-aircraft warfare
• Roller coasters
• Conveyor systems
• Beverage and food can making lines^[3]
• Mobile devices
• Touch screens that come in close proximity to the face
• Attenuating radio power in close proximity to the body, in order to reduce radiation exposure.

   1.4                                              SCOPE OF THE PROJECT

The project is designed to measure the proximity of any object by using an ultrasonic transducer. Ultrasonic means of proximity measurement is a convenient method compared to traditional one using measurement scales.

The total time taken from sending the waves to receiving it is calculated by taking into consideration the velocity of sound. The ultrasonic sensor produces 40 kHz sound waves.

1.5                                                  PROBLEM OF PROJECT

1. They are affected by temperature and humidity
2. Difficulties in designing

iii.  Capacitive proximity sensors are not as accurate compare to inductive sensors.

1.6                                          ADVANTAGES OF THE PROJECT

1. It can detect both metallic and non metallicØ
2. Good stability

• High Speed

1. Capacitive sensors are good in terms of power
2. Usage Low cost.

1.7                                        PROJECT WORK ORGANISATION

The various stages involved in the development of this project have been properly put into five chapters to enhance comprehensive and concise reading. In this project thesis, the project is organized sequentially as follows:

Chapter one of this work is on the introduction to this study. In this chapter, the background, significance, scope, objective, limitation and problem, advantages of this work was discussed.

Chapter two is on literature review of the study. In this chapter, all the literature pertaining to this work was reviewed.

Chapter three is on design methodology. In this chapter all the method involved during the design and construction were discussed.

Chapter four is on testing analysis. All testing that result accurate functionality was analyzed.

Chapter five is on conclusion, recommendation and references.