iv

DESIGN OF A PROTOTYPE ROBOTIC ARMMANIPULATOR BY USING MICRO CONTROLLER

A THESIS

Submitted in partial fulfillment of the requirements for the award of the degree

of

BACHELOR OF SCIENCE

IN

ELECTRICAL & ELECTRONIC ENGINEERING

BY

Under supervision

of

MD. ZAKIR HOSSAIN

ASSISTANT PROFESSOR

DEPARTMENT OF ELECTRICAL & ELECTRONIC ENGINEERING

DHAKA UNIVERSITY OF ENGINEERING & TECHNOLOGY (DUET), GAZIPUR,BANGLADESH

DECEMBER- 2010

MD. SOHEL KHANDAKER

MD. MAMUNUR RAHMAN (makhon)

SADAKAT HOSSAIN (sujon)

INDRAJIT KUMAR NANDY (biduyat)

Session # 2008-2009

v

ACKNOWLEDGEMENT

First of all, the author expresses his sincere thanks with regards and gratitude to

Professor Mohammad. Abdul Mannan, Head of the Department of Electrical & Electronic

Engineering, Dhaka University of Engineering & Technology Md. Zakir Hossain,

Assistant Professor of electrical and electronic engineering Department of the Dhaka

University Engineering & technology for his constant criticisms invaluable suggestion

constructive criticisms and encouragement during the preparation of this project.

Grateful thanks and appreciations are extended to other teachers of the Department of the

electrical and electronic engineering for their entire period during at DUET and on project

manuscript.

Grateful thanks are extended to the staff of the machine Lab & Electronic Lab for their co-

operation and help during the project period. Finally, we offer sincere thanks to them are

directly or indirectly helped us preparation of this project work.

vi

ABSTRACT

In this thesis we have designed a prototype Manipulator Robotic Arm. This Robotic

Arm design with the help of stepper motor and Microcontroller. Now, world is passing

heyday and being advance to the forward in all aspect. Recently, there has been wide-spread

demand of stepping motor with Robotic Arm because of the explosive growth of automation

industry. Their popularity is due to the fact that they can be controlled manually and

automatic by microcontroller, microprocessors and programmable controllers. So the entire

design is composed on software instead of hardware. Sophistic software provides the

necessary data from the Microcontroller. This program has been coded in MPLAB with CCS.

The entire design has been tested by executing the program. The performance of the software

is sufficient to satisfy the stepper motor based Robotic Arm.

vii

LIST OF FIGURE

FIGURE NO PAGE1.1 Block Diagram of this project 1

2.1 Stepper Motor Control Systems 4

2.2 Components of a PM Stepper Motor: (a) Rotor; (b) Stator 52.3 Cutaway Diagram of a Permanent Magnet Stepper Motor 72.4 Cross Section of VR Stepper Motor 82.5 Hybrid Stepper Motor 92.6 Unipolar stepper motor 92.7 Bipolar stepper motor 103.1 Ordering numbers: ULN2003A 143.2 Schematic diagram (ULN2003A): 153.3 Internal Inverter circuit of ULN-2003A 153.4 Test circuit of Driver IC (ULN2003A) 163.5 Physical structure of L298N 173.6 Internal circuit diagram of L298N 173.7 Pin connections of L298N 183.8 Physical view of PICMICRO-PIC16F877A 193.9 Pin diagram of PIC16F877A 225.1 power supply circuit diagram 305.2 Connection diagram of L298N with bipolar stepper motor 305.3 Circuit diagram of the system for one stepper motor 315.4 Block diagram of the System 315.5 Robotic arm with arm lengths (L1, L2) and Rotation angles (θ1, θ2) 335.6 Power circuit 345.7 Driver circuit 345.8 Microcontroller circuit 355.9 Base motor with mechanism 355.10 Elbow motor with mechanism 365.11 Gripper motor with mechanism 365.12 Control switch 375.13 Physical view of prototype robotic arm 37

viiivi

LIST OF TABLE

TABLE NO PAGE

2.1 Four step input sequence (Full step) 11

2.2 Eight step input sequence (Half step) 12

3.1 Absolute Maximum Ratings of ULN2003A 16

3.2 Thermal Data of ULN2003A 16

3.3 Absolute Maximum Ratings of L298N 18

3.4 Thermal Data of L298N 19

3.5 Specification of PIC microcontroller (PIC16F877A) 21

3.6 PIC16F877A Pinout Description 23

5.1 Major Circuit components 32

ix

CONTENTS

CHAPTER TITLE PAGE

ACKNOWLEDGMENT iv

ABSTRACT v

LIST OF TABLE vi

LIST OF FIGURE vii

LIST OF ABBREVIATIONS viii

CHAPTER-I: INTRODUCTION 1

1.1 Introduction 1

1.2 Present Status 2

1.3 Objective 3

CHAPTER-II: STEPPER MOTOR 4

2.1 Introduction 4

2.2 Operation of Stepper motor 5

2.3 Selection of Motor 6

2.4 Types of Stepper Motor 7

2.4.1 Types of Stepper Motors according

to construction 7

2.4.1(a) Permanent Magnet (PM) Stepper Motor 7

2.4.1(b) Variable Reluctance Stepper Motor 8

2.4.1(c) Hybrid Stepper Motor 8

2.4.2 Types of stepper motor according to

connection diagram 9

2.4.2(a) Unipolar stepper motor 9

2.4.2(b) Bipolar stepper motor 10

x

2.5 Stepper Motor Switching Sequence 11

2.6 Selection Criteria for Stepper Motor 12

2.7 Torque Calculation 13

2.8 Stepper Motor Applications 13

CHAPTE- III: DRIVER IC AND MICROCONTROLLER 14

3.1Introduction 14

3.2 Driver IC (ULN2003A) 14

3.2.1 Description of ULN2003A 15

3.2.2 Pin Connection 15

3.2.3 Test Circuits 16

3.3 Dual H- Bridge Driver (L298N) 17

3.3.1 Description of L298N 17

3.3.2 Internal Circuit Diagram of L298N 17

3.3.3 Pin Connections of L298N (Top View) 18

3.4 40-Pin Enhanced Flash Microcontrollers (PIC16F877 19

3.5 High-Performance RISC CPU 19

3.6 Peripheral Features 20

3.7 Features of PIC16F877A 20

3.7.1 Analog Features 20

3.7.2 Special Microcontroller Features 20

3.7.3 CMOS Technology 21

3.8 Pin Diagram of PIC16F877A 22

3.9 Function of Each Pin 23

3.10 Advantages Using Microcontroller over

Microprocessor 24

CHAPTER- IV: ROBOTICS 25

4.1 Introduction 25

4.2 Classification of Robots 25

xi

4.2.1 Autonomous Mobile Robots 26

4.2.2 Manipulator Robots 26

4.3 Applications of Robotics 27

4.4 Robotics in the Future 28

CHAPTER -V: SYSTEM DESIGN AND IMPLEMENTATION 30

5.1 Introduction 30

5.2 circuit of DC power supply 30

5.3 Stepper driver circuit 30

5.4 Circuit of the System 31

5.5 Block Diagram of the System 31

5.6 System Integration and Testing 32

5.7 Mechanical design of prototype robotic arm 33

5.8 Physical images of robotic part 34

CHAPTER –VI: RESULT AND DISCUSSION 38

6.1 Introduction 38

6.2 Result Analysis 38

6.3 Futures Scope 38

6.4 Conclusions 38

APPENDIX-I Flow Chart 40

APPENDIX-II Program Code 41

REFERENCES

xii

CHAPTER I

INTRODUCTION

1.1 Introduction:

This chapter will discuss on axis movement controller in Automation system and

its implementation to industry. The problem statement which contributes to the

creation and development of this project, overview, objective and scope of this project

is also presented in this chapter. This project is focusing on development of axis movement

controller for 2- axis configuration machine control or 4 degrees freedom. The movement of

the A uto ma t i on system design is driven by a (unipolar/Bipolar) stepper motor. The

project has prepared a driver for stepper motor to control automation system. The stepper

motor is control using PIC16F877A. The stepper motor used in this project has 48 pulses

and each pulse movement has 7.5 degree. The driver of a stepper motor that use in this

system is ULN2003 and L298N. This driver consists of 16 pinned with high input voltage

and current and H-Bridge consists of 15 pinned. The advantage of using this driver is

because the driver consist seven open collector Darlington pairs with common emitter and

L298N consists of high current with Analog properties.

Fig: 1.1 block diagram of this Project

Power Supply: 12V, 3A DC power supply is used from the step-down transformer which

is describing the chapter v.

Microcontroller: A microcontroller is an inexpensive single-chip computer. Single-chip

means that the entire computer system lies within the confines of the integrated circuit.

Briefly describe in chapter iii

POWERSUPPLY

MICROCONTROLLER

DRIVER

IC

STEPPERMOTOR

ROBOTICARM

CONTROL INPUT

xiii

Driver IC: The ULN2003 andULN2004A are high voltage, high current darling ton arrays

each containing seven open collector darling ton pairs with common emitters. Each channel

rated at 500mA and can withstand peak currents of 600mA. The L298 is an integrated

monolithic circuit in a 15- lead Multi watt and Power SO20 packages. It is a high voltage,

high current dual full-bridge driver designed to accept standard TTL logic levels and drive

inductive loads such as relays, solenoids, DC and stepping motors. Briefly describe in chapter

iii

Control Input: The prototype Robotic Arm control by four toggles switch. Switch 1, 2

and 3 control the three stepper motor start/stop (bipolar and Unipolar) and switch 4 used for

change of direction (clockwise and anti-clockwise).

Stepper Motor: A Stepper Motor is widely used devices that translate electrical pulses

into mechanical movement. The motor is called stepper motor because this motor rotates

through a fixed angular step in response to each input current pulse received by its controller.

These motors are also called stepping motors or step motors. Briefly describe in chapter ii.

Robotic Arm: There are various types of robots, which are used now in the modern world

each having one or several tasks that it performs depending on the intelligence applied to it. .

Most robots used now days are designed for heavy, repetitive manufacturing work. They are

specifically designed to handle certain tasks that are difficult, dangerous, or to boring to

human beings. Robots can do more work more efficiently than humans can since robots are

precise. Briefly describe in chapter iv

1.2 Present Status:The advent of robotics started in the year 350 B.C. when a Greek mathematician

Archytas of Tarentum built a mechanical bird, which was called “the pigeon”. This

mechanical bird was powered using steam. With further advancements, Leonardo Da Vinci in

the year, 1495 designed a mechanical device that looked like an armored knight. The knight

was designed to move as if there was a real person inside. In 1898, Nikola Tesla designed the

first remote-controlled robot in Madison Square Garden. The robot designed was modeled

after a boat. The first industrial robots were Unimates developed by George Devol and Joe

Engelberger in the late 50’s and early 60’s. The first patents were by Devol but Engelberger

formed Animation which was the first market robots. Therefore, Engelberger has been called

the “father of robotics”. For a while, the economic viability of these robots proved disastrous

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and thing slowed down for robotics. However, by mid-80’s, the industry recovered and

robotics was back on track. George Devol Jr, in 1954 developed the multi-jointed artificial

arm, which lead to the modern robots. However, mechanical engineer Victor Scheinman,

developed the truly flexible arm know as the Programmable Universal Manipulation Arm

(PUMA).

In 1950, Isaac Asimov came up with laws for robots and these were:

A robot may not injure a human being, or through inaction allow a human being to

come to harm.

A robot must obey the orders given it by human beings, except where such orders

would conflict with the first law.

A robot must protect its own existence as long as such protection does not conflict

with the first or second law (Robotics Introduction. 2001).

Mobile Robotics moved into its own in 1983 when Odetics introduced a six-legged vehicle

that was capable of climbing over objects. This robot could lift over 5.6 times its own weight

parked and 2.3 times it weight moving. There were very significant changes in robotics until

the year 2003 when NASA launched two robots MER-A “Spirit” and MERB “Opportunity”

rovers which were destined for Mars. Up till date, Roboticists have kept researching on how

to make robots very interactive with man in order to be able to communicate efficiently in the

social community.

1.3 Project Objective

The objective of this project is the development of axis movement controller for 2-

axis/4 degrees freedom configuration machine control. The project has prepared a driver

for stepper motor to control indus t r ia l au tomat ion system. The motor will rotate one

step per digital signal change which is controlled by manual switch.

xv

CHAPTER II

STEPPER MOTOR

2.1 Introduction:

A Stepper Motor is widely used devices that translate electrical pulses into

mechanical movement. The motor is called stepper motor because this motor rotates through

a fixed angular step in response to each input current pulse received by its controller. These

motors are also called stepping motors or step motors. This section of the stepper tutorial

deals with the basic final stage drive circuitry for stepping motors. This circuitry is centered

on a single issue, switching the current in each motor winding on and off, and controlling its

direction. The circuitry discussed in this section is connected directly to the motor windings

and the motor power supply, and this circuitry is controlled by a digital system that

determines when the switches are turned on or off. This section covers all types of motors,

from the elementary circuitry needed to control a variable reluctance motor, to the H-bridge

circuitry needed to control a bipolar permanent magnet motor. Each class of drive circuit is

illustrated with practical examples, but these examples are not intended as an exhaustive

catalog of the commercially available control circuits, nor is the information given here

intended to substitute for the information found on the manufacturer's component data sheets

for the parts mentioned. This section only covers the most elementary control circuitry for

each class of motor. All of these circuits assume that the motor power supply provides a drive

voltage no greater than the motor's rated voltage, and this significantly limits motor

performance. The next section, on current limited drive circuitry, covers practical high-

performance drive circuits.

Fig: 2.1 Stepper Motor Control Systems

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The first element, the indexer, is a microprocessor capable of generating pulses and direction

signals to the driver. The second element is the driver and converts the indexer command

signal into the power necessary to energize the motor winding. The last element is the step

motor which is an electromagnetic device that converts the digital pulses into mechanical

shaft rotation. Advantages of step motors (compared to other types of motors) are low cost,

high reliability, high torque at low speeds and a simple rugged construction that operates in

almost any environment. The disadvantages of step motors are resonance effects at low

speeds and decreasing torque with increasing speed.

Fig: 2.2 Components of a PM Stepper Motor: (a) Rotor; (b) Stator

2.2 Operation of Stepper Motors:

Stepper motors provide means for precise positioning and speed control without the

use of feedback sensors. The basic operation of the stepper motor allows the shaft to move a

precise number of degrees each time a pulse of electricity is sent to the motor. The shaft of

the motor moves only the number of degrees that it was designed for when each pulse is

delivered. We can control these pulses that are sent and control the positioning and speed.

The rotor of the motor produces torque from the interaction between the magnetic field in the

stator and rotor. The strength of the magnetic field is proportional to the amount of the

current sent to the stator and number of turns in the windings. The stepper motor uses

electromagnetic theory to make the motor shaft turn a precise distance when a pulse of

xvii

electricity is provided. Like poles of a magnet repel and unlike poles attract. Figure 2.2 shows

a typical cross-sectional view of the rotor and stator of a stepper motor. From this diagram we

can see that stator has four poles, and the rotor has six poles. So the rotor will require 48

pulses of electricity to move the 48 steps to make one complete revolution. Another way to

say this is that the rotor will move precisely 7.5 degrees for each pulse of electricity the motor

receives. When no power is applied to the motor, the residual magnetism in the rotor magnets

will cause the rotor to detent or align one set of its magnetic pole with the magnetic poles of

one of the stator magnets. This means that the rotor will have 48 possible detent positions.

When the rotor is in a detent position, it will have enough magnetic force to keep the shaft

from moving to the next position. This is what makes the rotor feel like it is clicking from

one position to the next as you rotate the rotor by hand with no power applied. When power is

applied, it is directed to only one of the stator pairs of windings, which will cause that

winding pair to become a magnet. One of the coils for the pair will become the north pole,

and the other will become the south pole. When this occurs, the stator coil that is the north

pole will attract the closest rotor tooth that has the opposite polarity, and the stator coil that is

the south pole will attract the closest rotor tooth that has the opposite polarity. When current

is flowing through these poles, the rotor will now have a much stronger attraction to the stator

winding, and the increased torque is called the holding torque. The magnetic field in the

stator is continually changed as the rotor moves through the 48 steps to move a total of 360°.

2.3 Selection of Motor:

Stepper Motors have several features which distinguish them from AC Motors,

and DC Servo Motors.

• Brushless - Steppers are brushless. Motors with contact brushes create sparks,

undesirable in certain environments. (Space missions, for example.)

• Holding Torque - Steppers have very good low speed and holding torque.

Steppers are usually rated in terms of their holding force (oz/in) and can even hold a

position (to a lesser degree) without power applied, using magnetic 'detent' torque.

• Open loop positioning - Perhaps the most valuable and interesting feature of a

stepper is the ability to position the shaft in fine predictable increments, without need to

query the motor as to its position. Steppers can run 'open-loop' without the need for any

kind of encoder to determine the shaft position. Closed loop systems- systems that feed

back position information, are known as servo systems. Compared to servos, steppers are

xviii

very easy to control; the position of the shaft is guaranteed as long as the torque of the

motor is sufficient for the load, under all its operating conditions.

• Load Independent - The rotation speed of a stepper is independent of load,

provided it has sufficient torque to overcome slipping. The higher rpm a stepper motor is

driven, the more torque it needs, so all steppers eventually poop out at some rpm and start

slipping. Slipping is usually a disaster for steppers, because the position of the shaft

becomes unknown. For this reason, software usually keeps the stepping rate within a

maximum top rate. In applications where a known RPM is needed under a varying load,

steppers can be very handy.

2.4Types of Stepper Motor:

2.4.1Types of Stepper Motors according to construction:

Three basic types of stepper motors include the permanent magnet motor, the variable

reluctance motor, and the hybrid motor, which is combination of previous two.

2.4.1(a) Permanent Magnet (PM) Stepper Motor:

A PM stepper motor operates on the reaction between a permanent-magnet rotor and

an electromagnetic field. Figure 2.3 shows a cutaway diagram of a typical permanent magnet

stepper motor. The rotor shows that the permanent magnet motor can have multiple rotor

windings, which means that the shaft for this type of stepper motor will turn fewer degrees as

each pulse of current is received at the stator.

Fig: 2.3 Cutaway Diagram of a Permanent Magnet Stepper Motor

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2.4.1(b) Variable Reluctance Stepper Motor:

The VR stepper motor at its core basically differs from the PM stepper in that it has

no permanent-magnet rotor and thus no residual torque to hold the rotor at one position when

turned off. This means the field strength can be varied. The stator of a variable-reluctance

stepper motor has a magnetic core constructed with a stack of steel laminations. The rotor is

made of demagnetized soft steel with teeth and slots, or any other such magnetically

permeable substance, unlike PM stepper motors. When the stator coils are energized, the

rotor teeth will align with the energized stator poles. In the non-energized condition there is

no magnetic flux in the air gap so there is no detent torque. This type of motor operates on the

principle of minimizing the reluctance along the path of the applied magnetic field. By

alternating the windings that are energized in the stator, the stator field changes, and the rotor

moves to a new position.

Fig 2.4 Cross Section of VR Stepper Motor

2.4.1(c) Hybrid Stepper Motor:

Construction of PM stepper motor becomes very complex below 7.5 deg step angles.

Smaller step angles can be realized by combining permanent magnet stepper motor and

variable reluctance stepper motor. Torque is created in the hybrid motor by the interaction of

the magnetic field of the permanent magnet and the magnetic field produced by stator

windings.

xx

Fig 2.5 Hybrid Stepper Motor

A typical hybrid motor is shown in Fig. 2.5. The stator construction is similar to the

permanent magnet motor, and the rotor is cylindrical and magnetized like the PM motor with

multiple teeth like a VR motor. The teeth on the rotor provide a better path for the flux to

flow through the preferred locations in the air gap. This increases the detent, holding, and

dynamic torque characteristics of the motor compared to the other two types of motors.

Hybrid motors have a smaller step angle compared to the permanent magnet motor, but they

are very expensive. In low cost applications, the step angle of a permanent magnet motor is

divided into smaller angles using better control techniques. Permanent magnet motors and

hybrid motors are more popular than the variable reluctance motor, and since the stator

construction of these motors is very similar, a common control circuit can easily drive both

types of motors.

2.4.2 Types of stepper motor according to connection diagram:

2.4.2(a) Unipolar stepper motor:

Fig 2.6 Unipolar stepper motor

xxi

Unipolar stepping motors, both permanent magnet and hybrid stepping motors with 5

or 6 wires are usually wired as shown in the schematic in Figure 2.6 with a center tap on

each of two windings. In use, the center taps of the windings are typically wired to the

positive supply, and the two ends of each winding are alternately grounded to reverse

the direction of the field provided by that winding.

The motor cross section shown in Figure 2.6 is of a 7.5 degree per step permanent

magnet or hybrid motor. The difference between these two motor types is not relevant at

this level of abstraction. Motor winding number 1 is distributed between the top and

bottom stator pole, while motor winding number 2 is distributed between the left and right

motor poles. The rotor is a permanent magnet with 6 poles,

3 souths and 3 norths, arranged around its circumference.

2.4.2(b) Bipolar stepper motor:

Fig 2.7 Bipolar stepper motor

Bipolar permanent magnet and hybrid motors are constructed with exactly the same

mechanism as is used on unipolar motors, but the two windings are wired more simply, with

no center taps. Thus, the motor itself is simpler but the drive circuit needed to reverse the

polarity of each pair of motor poles is more complex. The schematic in Figure 2.7 shows

how such a motor is wired. The motor cross section shown here is exactly the same as the

cross section shown in Figure 2.6.

To distinguish a bipolar permanent magnet motor from other 4 wire motors, measure the

resistances between the different terminals. It is worth noting that some permanent magnet

stepping motors have 4 independent windings, organized as two sets of two. Within each

set, if the two windings are wired in series, the result can be used as a high voltage bipolar

motor. If they are wired in parallel, the result can be used as a low voltage bipolar motor.

If they are wired in series with a center tap, the result can be used as a low voltage unipolar

motor.

xxii

2.5 Stepper Motor Switching Sequence:To enable rotation of the rotor the magnetic field generated by the stator windings has

to interact and drive the rotor flux, which is achieved by switching the direction of current

flow through each winding. Stepper motor switching sequences are mainly two types, Such

as Full step and Half step .The switching sequences for the stepper motor are as described

below.

Full-step: The stepper motor uses a four-step switching sequence, which is called a

full-step switching sequence. Each of the windings is tapped at one end and they are

connected through a resistor to the negative terminal of the power supply.

Table 2.1 Four step input sequence (Full step ):

STEP SW1 SW2 SW3 SW41 1 0 1 02 1 0 0 13 0 1 0 14 0 1 1 01 1 0 1 0

The table 2.1 shows the sequence for energizing the coils. During the first step of the

sequence, switches SW1 and SW3 are on and the other two are off. During the second step of

the sequence, switches SW1 and SW4 are on and the other two are off. During the third step

of the sequence, SW2 and SW4 are on and the other two are off. During the fourth step of the

sequence, SW2 and SW3 are on and the other two are off. This sequence continues through

four steps, and then the same four steps are repeated again. These steps cause the motor to

rotate one step or tooth on the rotor when a pulse is applied by closing two of the switches.

This “Two Phase On” method gives 41.4 % more torque compared to “One Phase On”

method.

Half-step: Another switching sequence for the stepper motor is called an eight-step

or half-step sequence. The switching diagram for the half-step sequence is shown in Table

2.2. The main feature of this switching sequence is that you can double the resolution of the

stepper motor by causing the rotor to move half the distance it does when the full-step

switching sequence is used. This means that a 48step motor, which has a resolution of 7.5°,

xxiii

will have a resolution of 96 steps and 3.75°. The way the controller gets the motor to reach

the half-step is to energize both phases at the same time with equal current.

Table 2.2 Eight step input sequence (Half step):

STEP SW1 SW2 SW3 SW41 1 0 1 02 1 0 0 03 1 0 0 14 0 0 0 15 0 1 0 16 0 1 0 17 0 1 1 08 0 0 1 01 1 0 1 0

In this sequence the first step has SW1 and SW3 on, and SW2 and SW4 are off. The

sequence for the first step is the same as the full-step sequence. The second step has SW1 on

and all of the remaining switches are off. This configuration of switches causes the rotor to

move an additional half-step. The third step has SW1 and SW4 on, and SW2 and SW3 are

off, which is the same as step 2 of the full-step sequence. The sequence continues for eight

steps and then repeats. The main difference between this sequence and the full-step sequence

is that steps 2, 4, 6, and 8 are added to the full-step sequence to create the half-step moves.

2.6 Selection criteria for stepper motor:

When a stepper motor is selected, eight different things must be considered:

1. Operating speed in steps/second

2. Torque in oz-in.

3. Load inertia in lb-in.P2P

4. Required step angle resolution

5. Time to accelerate in ms

6. Time to decelerate in ms

7. Type of drive to be used

8. Size and weight considerations

xxiv

2.7 Torque Calculation:

The formula for calculating the torque is as below:

Torque (oz-in)

T=Fr………………………………………….(1)

Where F= force in oz

r = radius in inch

2.8 Stepper Motor Applications:

Stepper motors are used in a wide variety of applications in industry, including

computer peripherals, business machines, motion control, and robotics, which are included in

process control and machine tool applications. A partial list of applications is shown below.

a. Computer Peripherals:Floppy diskPrinterTape ReaderPlotter

b. Business Machines:Card ReaderCopy MachineBanking systemType WriterCard sorter

c. Process Control:Valve controlConveyorAssembly linesLaser trimmingMail handling system

d. Machine Tools:Milling MachineDrilling MachineGrinding MachineLaser CuttingSewing

xxv

CHAPTER III

DRIVER IC AND MICROCONTROLLER

3.1 Introduction:A microcontroller is an inexpensive single-chip computer. Single-chip means that the

entire computer system lies within the confines of the integrated circuit. The microcontrollers

existing on the encapsulated silver of silicon have features and similarities to our standard

personal computers. Primarily, the microcontroller is capable of storing and running a

program. Microcontrollers are frequently used in automatically controlled products and

devices, such as automobile engine control systems, office machines, appliances, power tools,

and toys. By reducing the size, cost, and power consumption compared to a design using a

separate microprocessor, memory, and input/output devices, microcontrollers make it

economical to electronically control many more processes. The ULN2003 andULN2004A are

high voltage, high current darling ton arrays each containing seven open collector darling ton

pairs with common emitters. Each channel rated at 500mA and can withstand peak currents

of 600mA. The L298 is an integrated monolithic circuit in a 15- lead Multi watt and Power

SO20 packages. It is a high voltage, high current dual full-bridge driver designed to accept

standard TTL logic levels and drive inductive loads such as relays, solenoids, DC and

stepping motors.

3.2 Driver IC (ULN2003A):

Fig 3.1 Ordering numbers: ULN2003A

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3.2.1 Function of ULN2003A:The ULN2003A andULN2004A suppression diodes are included for inductive load

driving and the inputs are pinned opposite the outputs to simplify board layout. The two

versions interface to all common logic families. These versatile devices are useful for driving

a wide range of loads including solenoids, relays DC motors. LED displays filament lamps,

thermal print heads and high power buffers. The ULN2003A and 2004A are supplied in 16

pin plastic DIP packages with a copper lead frame to reduce thermal resistance.

3.2.2 Pin Connection:

Fig 3.2 Schematic diagram (ULN2003A):

Fig 3.3 Internal Inverter Circuit of ULN-2003A

xxvii

Table 3.1 Absolute Maximum Ratings of ULN2003A:

Symb

ol

Parameter Value Unit

Vo Output Voltage 50 V

Vin Input Voltage (for ULN2002A/D - 2003A/D - 2004A/D) 30 V

Ic Continuous Collector Current 500 mA

Ib Continuous Base Current 25 mA

Tamb Operating Ambient Temperature Range -20 to 85 C

Tstg Storage Temperature Range -55 to 150 C

T Junction Temperature 150 C

Table 3.2 Thermal Data of ULN2003A:

Symbol Parameter DIP16 SO16 Unit

Rth j-amb Thermal Resistance Junction-ambient

Max.

70 120 C/W

3.2.3 Test Circuits:

Figure 3.4 Test circuit of Driver IC (ULN2003A)

xxviii

3.3 Dual H- Bridge Driver (L298N):

Operating Supply voltage up to 46 v

Total dc current up to 4 amp

Low saturation voltage

Over temperature protection

logical "0" input voltage up to 1.5 v (high noise immunity)

Fig 3.5 Physical structure of L298N

3.3.1 Function of L298N:The L298N two enable inputs are provided to enable or disable the device

independently of the input signals. The emitters of the lower transistors of each bridge are

connected together and the corresponding external terminal can be used for the connection of

an external sensing resistor. An additional supply input is provided so that the logic works at

a lower voltage.

3.3.2 Internal circuit diagram of L298N:

Fig 3.6 Internal circuit diagram of L298N

xxix

Table 3.3 Absolute Maximum Ratings of L298N :

Symbol Parameter Value UnitVS Power Supply 5

0V

VSS Logic Supply Voltage 7 V

VI,Ven Input and Enable Voltage –0.3to 7

VIO Peak Output Current (each Channel)

– Non Repetitive (t = 100 s)–Repetitive (80% on –20% off; ton = 10ms)

–DC Operation

32.5

2

AAA

Vsens Sensing Voltage –1 to 2.3 V

Ptot Total Power Dissipation (Tcase = 75 C) 25 W

Top Junction Operating Temperature –25 to 130 C

Tstg, Tj Storage and Junction Temperature –40 to 150 C

3.3.3 Pin connections (top view):

Fig 3.7 Pin connections of L298N

xxx

Table 3.4 Thermal Data of L298N:

Symbol Parameter PowerSO20 Multiwatt

15

Unit

Rth j-case Thermal Resistance Junction-

case Max.

– 3 C/W

Rth j-amb Thermal Resistance Junction-

ambient Max.

13 (*) 3

5

C/W

(*) Mounted on aluminum substrate

3.4 40-Pin Enhanced Flash Microcontrollers (PIC16F877A):

Fig 3.8 Physical view of PICMICRO-PIC16F877A

3.5 High-Performance RISC CPU:• Only 35 single-word instructions to learn

• All single-cycle instructions except for program branches, which are two-cycle

• Operating speed:

1. DC – 20 MHz clock input

2. DC – 200 ns instruction cycle

• Up to 8K x 14 words of Flash Program Memory, Up to 368 x 8 bytes of Data Memory

(RAM), Up to 256 x 8 bytes of EEPROM Data Memory.

• Pin out compatible to other 28-pin or 40/44-pin, PIC16CXXX and PIC16FXXX

microcontrollers.

xxxi

3.6 Peripheral Features:

• Timer0: 8-bit timer/counter with 8-bit prescaler

• Timer1: 16-bit timer/counter with prescaler, can be incremented during Sleep via external

crystal/clock

• Timer2: 8-bit timer/counter with 8-bit period register, prescaler and postscaler

• Two Capture, Compare, PWM modules

- Capture is 16-bit, max. Resolution is 12.5 ns

- Compare is 16-bit, max. Resolution is 200 ns

- PWM max. Resolution is 10-bit

• Synchronous Serial Port (SSP) with SPI™ (Master mode) and I2C™ (Master/Slave)

• Universal Synchronous Asynchronous Receiver, Transmitter (USART/SCI) with 9-bit

address detection

• Parallel Slave Port (PSP) – 8 bits wide with external RD, WR and CS controls (40/44-pin

only)

• Brown-out detection circuitry for Brown-out Reset (BOR)

3.7 Features of PIC16F877A:3.7.1 Analog Features:

• 10-bit, up to 8-channel Analog-to-Digital Converter (A/D)

• Brown-out Reset (BOR)

• Analog Comparator module with:

- Two analog comparators

- Programmable on-chip voltage reference (VREF) module

- Programmable input multiplexing from device inputs and internal voltage reference

- Comparator outputs are externally accessible

3.7.2 Special Microcontroller Features:

• 100,000 erase/write cycle Enhanced Flash program memory typical

• 1,000,000 erase/write cycle Data EEPROM memory typical

• Data EEPROM Retention > 40 years

• Self-reprogrammable under software control

• In-Circuit Serial Programming™ (ICSP™) via two pins

• Single-supply 5V In-Circuit Serial Programming

• Watchdog Timer (WDT) with its own on-chip RC oscillator for reliable operation

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• Programmable code protection

• Power saving Sleep mode

• Selectable oscillator options

• In-Circuit Debug (ICD) via two pins

3.7.3 CMOS Technology:

• Low-power, high-speed Flash/EEPROM technology

• Fully static design

• Wide operating voltage range (2.0V to 5.5V)

• Commercial and Industrial temperature ranges

• Low-power consumption

Table 3.5 Specification of PIC microcontroller (PIC16F877A)

Device

Program

Memory

Data

SRAM

(Bytes)

EEPROM

(Bytes)

I/

O

10-

bit

A/D

(ch)

CCP

(PWM)

MSSP

USA

RT

Timer

s

8/16-

bit

Co

mp

ara

tor

s

SP

I

SPI

Mas

.

I2C

Bytes

Ins.

set

16F877

A

14.3K 8192 368 256 33 8 2

Ye

s Yes Yes 2/1 2

xxxiii

3.8 Pin Diagram of PIC16F877A:

Fig 3.9 Pin diagram of PIC16F877A

xxxiv

3.9 Function of Each Pin:

Table 3.6 PIC16F877A Pinout Description

Pin Name PDIPPin#

PLCCPin#

TQFPPin#

QFNPin#

I/O/PType

BufferType

Details

RD0/PSP0RD0

PSP0RD1/PSP1

RD1PSP1

RD2/PSP2RD2

PSP2RD3/PSP3

RD3PSP3

RD4/PSP4RD4

PSP4RD5/PSP5

RD5PSP5

RD6/PSP6RD6

PSP6RD7/PSP7

RD7PSP7

19

20

21

22

27

28

29

30

21

22

23

24

30

31

32

33

38

39

40

41

2

3

4

5

38

39

40

41

2

3

4

5

I/OI/O

I/OI/O

I/OI/O

I/OI/O

I/OI/O

I/OI/O

I/OI/O

I/OI/O

ST/TTL(3)

ST/TTL(3)

ST/TTL(3)

ST/TTL(3)

ST/TTL(3)

ST/TTL(3)

ST/TTL(3)

ST/TTL(3)

PORTD is abidirectional I/O port

Digital I/O.

Digital I/O.

Digital I/O.

Digital I/O.

Digital I/O.

Digital I/O.

Digital I/O.

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RE0/RD/AN5

RE0RDAN5

RE1/WR/AN6

RE1WRAN6

RE2/CS/AN7RE2CSAN7

8

9

10

9

10

11

25

26

27

25

26

27

I/OII

I/OII

I/OII

ST/TTL(3)

ST/TTL(3)

ST/TTL(3)

PORTE bidirectionalI/O port.

Digital I/O.ReadcontrolforParallelSlavePort.Analoginput 5.

Digital I/O.WritecontrolforParallelSlavePort.Analoginput 6.

Digital I/O.Chip selectcontrol forParallelSlave Port.Analog input7.

VSS 12, 31 13,34

6, 29 6,30,31

P — Ground

VDD 11, 32 12,35

7, 28 7, 8,28,29

P — Positive supply

NC — 1, 17,28,40

12,13,33, 34

13 — — not internallyconnected.

left unconnected.

3.10 Advantages Using Microcontroller over Microprocessor:

A microcontroller (MCU) is a computer-on-a-chip. It is a type of microprocessor

emphasizing self-sufficiency and cost-effectiveness, in contrast to a general-purpose

microprocessor. The only difference between a microcontroller and a microprocessor is that a

microprocessor has three parts - ALU, Control Unit and registers (like memory), while the

microcontroller has additional elements like ROM, RAM etc. The advantage of using MCU

is a microcontroller is an inexpensive single-chip computer. Single-chip means that the entire

computer system lies within the confines of the integrated circuit. The microcontroller

contains a central processing unit (CPU), random-access memory (RAM), read-only memory

(ROM), electrical erasable Programmable read-only memory (EEPROM), input/output (I/O)

lines, serial and parallel ports, timer and other built-in peripherals, such as ADC (analog-

digital converter) and DAC (digital analog converters. The most common microcontroller use

is PIC (Microchip), (Motorola), etc.

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CHAPTER IV

ROBOTICS

4.1 Introduction:The word robot is derived from the term robota which is generally translated as

'forced labor.' This means that the original conception of a robot, as far the etymology of the

word is concerned, was to be a capable servant. In the play, robots were portrayed as small

artificial and anthropomorphic creatures strictly. From this humble conception, many authors

began getting inspirations from the concept of a robot. It was formulated the four laws of

robots: (0) a robot may not injure humanity, or through inaction, allow humanity to come to

harm, (1) a robot may not injure or harm a human being, or through inaction, allow a human

being to come to harm, (2) a robot must obey orders given to it by human beings, except

where such orders would conflict the 0th or 1st law, and (3) a robot must protect its own

existence as long as such protection does not conflict with the previous laws. As time passed,

people began formulating an encompassing definition of a robot. As currently defined, robots

exhibit three key elements: (1) programmability, implying computational or symbolic

manipulative capabilities that a designer can combine as desired (a robot is a computer), (2)

mechanical capability, enabling it to act on its environment rather than merely function as a

data processing or a computational device (a robot is a machine), and (3) flexibility, in that it

can operate using a range of programs and manipulate and transports materials in a variety of

ways. This kind of description does not sway too far from what really most robots in the

world are doing. Most robots used now days are designed for heavy, repetitive manufacturing

work. They are specifically designed to handle certain tasks that are difficult, dangerous, or to

boring to human beings. Robots can do more work more efficiently than humans can since

robots are precise.

4.2 Classification of Robots:There are various types of robots, which are used now in the modern world each having

one or several tasks that it performs depending on the intelligence applied to it. However,

robots can be classified broadly into two types namely:

Autonomous Mobile Robots

Manipulator Robots

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4.2.1 Autonomous Mobile Robots:

These are mobile robots provided with the mechanisms to perform certain tasks such

as locomotion, sensing, localization, and motion planning. Autonomous mobile robots are

capable of adapting to their environment. The intelligence provided to them enables them to

be able to sense conditions around their environment and respond correctly to the situations.

Examples of Autonomous mobile robots include the autonomous guided vehicle robots which

independent of external human actions deliver parts between various assembly stations by

following special electrical guide wires using a custom sensor, the HELPMATE service robot

which transports food and medication throughout hospitals by tracking the position of ceiling

lights, which are manually specified to the robot before hand. Also, in the military, some

robots are designed to detect bombs and they are capable of defusing the bombs. These robots

are all autonomous in the task they perform because they have been provided with the

intelligence to detect and adapt to the environment in which they are supposed to perform

their tasks.

4.2.2 Manipulator Robots:

These are robots that perform particular tasks. They are usually in the form of robot

arms and are normally stationary. In most cases, they are bolted at the shoulder to a specific

position in the assembly line, and the robot arm can move with great speed and accuracy to

perform repetitive tasks such as spot welding and painting. Manipulator robots are very much

unlike the autonomous mobile robots whereby the intelligence provided to them does not

make them adapt to the environment in which they are. In most cases, most manipulator

robots are capable of handling many end-effectors in order to increase the versatility of their

use. These various end-effectors can be used for several purposes such as welding, painting,

screwing and assembling. Although manipulator robots can be very versatile, they suffer

from a fundamental disadvantage, which is lack of mobility. A fixed manipulator robot has a

limited range of motion that depends on where it is bolted down, in contrast to a mobile robot

that is capable of moving about.

xxxviii

4.3 Applications of Robotics:

Robotics is becoming almost very popular in today’s world and is now applied in

several spheres of the human life. Robotics is applied in the following areas of life.

●Medicine:

In the medical field, some robots are used for performing tasks, which are dangerous and

unpleasant to humans. Some of these hazardous jobs are handling materials such as blood or

urine samples. In addition, some robots are used to transport materials around the hospital.

Their main sensor for localization is a camera looking at the ceiling. The camera detects the

lamps on the ceiling as landmarks.

●Military:

Robots in the military are used for detecting enemy equipment, detection and defusing of

bombs. In rescue operations, robots are also used for searching buildings for fugitives and

deep-water search. Also, during military attacks, guided missiles are used to blast specific

locations on the earth.

●Education and Research:

Some robots are designed for demonstration purposes, which are used for educating the

public. For example, the Howard County Sheriff's department of Kokomo Indiana, in 1999

used a motor robot with a cop in it to attract a lot of attention to promote a seat belt program

at a fair and they had the robot with the cop with his seat belt on.In space research and the

Mars research, robots are usually sent out with the space shuttle for them to obtain samples

and bring them back to earth. These robots are usually controlled from a control room in

earth.

●Entertainment:

Some robots are used for entertainment purposes. These robots are designed like puppets and

could make some funny moves which amuse people. Olden day robots were mainly like this.

They were being used to entertain royalties.

●Industry:

In the industry, robots are used to perform precise and heavy tasks which are very difficult

for humans to perform. Autonomous mobile robots could be used for carry heavy

xxxix

components from one place to another using custom sensor that help them get their precise

positions. Manipulator robots are used to perform certain tasks such as painting, welding,

screwing and other activities that would have been difficult to handle using the human hand.

Also, manipulator robots are used in assembly lines where each robot takes care of a

particular stage of the assembly process.

4.4 Robotics In The Future:Today, robots are doing human labor in all kinds of places. Best of all, they are doing

the jobs that are unhealthy or impractical for people. This frees up workers to do the more

skilled jobs, including the programming, maintenance and operation of robots.

Robots that work on cars and trucks are used for welding and assembling parts, or lifting

heavy parts - the types of jobs that involve risks like injury to your back and arm or wrist, or

they work in environments filled with hazards like excessive heat, noise or fumes dangerous

places for people. Robots that assemble and pack cookies or other foodstuff do so without the

risk of carpal tunnel injury, unlike their human counterparts. Robots that make computer

chips are working in such tiny dimensions that a person couldn't even do some of the

precision work required. In the health industry, robots are helping to research and develop

drugs, package them and even assist doctors in complicated surgery such as hip replacement

and open heart procedures. And the main reason robots are used in any application is because

they do the work so much better that there is a vast improvement in quality and/or

production, or costs are brought down so that companies can be the best at what they do

while keeping workers safe. The changes in future robots that will revolutionalize our way of

living will occur in a subtle fashion. It will happen when we wake up one morning thinking

about the past and realize that the things we take for granted are exceptionally different than

they were when we were younger. In time, just as innovations like the light bulb and

telephone elevated life, as we know it to new standards, so will robotics incorporate itself in

our everyday lives. Discussed below are the various ways the field of robotics can affect our

lives as proposed by the Robotics Industries Association.

Virtual Travel - People will be able to visit each other without traveling. They will do this

by taking control of a robot at their desired vacation destination, and use the Internet to

transmit all the sensory information back and forth. What will this mean? Doctors will make

"house calls" again. Long distance relationships will never be the same. Families spread

across the globe can play games together. And perhaps most importantly, people will think

xl

nothing of having a satisfying conversation with a mechanical contraption made of

aluminum, plastic, and silicon

Housekeeping by Choice - The physical environments we live in will take care of

themselves. Machines will do the routine chores around the house. We will choose when it is

time for the extraordinary. Our houses and apartments will keep themselves swept and

scrubbed clean. There will be no piles of laundry, and your basic dinner will be moments

away. Machines will not have replaced us. But they will give us the opportunity to build on

the routine and create the unusual, brilliant, or just different. Robots will raise the standard

upon which we will build. They will give us a chance to dream and the time to live life to the

fullest

Artificial Intelligence - Perhaps the most dramatic changes in future robots will arise from

their increasing ability to reason. The field of artificial intelligence is moving rapidly from

university laboratories to practical application in industry, and machines are being developed

that can perform cognitive tasks, such as strategic planning and learning from experience.

Increasingly, diagnosis of failures in aircraft or satellites, the management of a battlefield, or

the control of a large factory will be performed by intelligent computers. Like the term

"robot" itself, artificial intelligence is hard to define. Ultimate AI would be a recreation of the

human thought process -- a man-made machine with our intellectual abilities. This would

include the ability to learn just about anything, the ability to reason, the ability to use

language and the ability to formulate original ideas. Roboticists are nowhere near achieving

this level of artificial intelligence, but they have had made a lot of progress with more limited

AI. Today's AI machines can replicate some specific elements of intellectual ability.

Pickbot and Industrial Robot: Pickbot is one of the industrial robot that commonly use in

industries. Pickbots growing in complexity and their use in industry is becoming more

widespread. The main use of industrial robots has been in the automation of mass production

industries, where the same, definable tasks must be performs repeatedly in exactly the same

fashion. Car production is the primary example for the employment of large and complex

robots for producing goods. Industrial robots are use in that process for the painting, welding

and assembly of the cars. Industrial robots are good for such tasks because the tasks can be

accurately defined and must be performed the same every time, with little need for feedback

to control the exact process being performed. Industrial robots can be manufacture in a wide

range of sizes and so can handle more tasks requiring heavy lifting than a human could.

xli

CHAPTER V

SYSTEM DESIGN AND IMPLEMENTATION

5.1 Introduction:The important thing for circuit development is need to chose the component that will

be used to build the main circuit. The component is chosen because of specification that will

suitable for the project. This research is doing by literature review in previous chapter. Table

below show the list component that will be used to develop this project. This project has

Three main circuits that need to be developed. This three main circuit is depending on each

other. The circuits that need to build are:

5.2 Circuit of DC Power Supply:

Fig 5.1 power supply circuit diagram

5.3 Stepper driver circuit:

Fig 5.2 Connection diagram of L298N with bipolar stepper motor

xlii

5.4 Circuit of the System:

Fig 5.3 Circuit Diagram of the System for One Stepper Motor

5.5 Block Diagram of the System:

Fig 5.4 Block diagram of the System

xliii

Table 5.1 Major Circuit components

Component Explanation/specification CompanyPIC 16F877A Microcontroller: To control the input and

outputMicrochip Technology inc.

Resistor 10K ,1K,4.7K ohmVoltageregulator

Give exact value +5v tomicrocontroller(7805 ,7812)

Capacitor 100uF, 33uFswitch For rest application(push), toggle switchCrystal 4Mhz ResonatorSwitch Input switch for control this projectDriver IC ULN2003A and L298N

5.6 System Integration and Testing:The robot arm design project was split into smaller tasks to reduce complexity and

also to facilitate parallel implementation of independent tasks. The tasks include robot arm

fabrication, gear design and assembly, control circuit design and implementation for both the

GUI and microcontrollers. These tasks were allocated among the members of the group and

we constantly met to establish and update guidelines that will ensure the compatibility of the

various modules during system integration. Most of the circuits were first implemented on

bread boards before transferring to printed circuit boards apart from the very simple ones. We

tested the individual circuit boards for basic errors and also for functionality where

applicable. During testing, some components were damaged and replaced. Having tested the

various modules, the system integration was done in stages. All the individual circuits were

integrated and tested. Some power supply issues were encountered, such as supply voltage

dropping significantly when loaded and undue heating of the voltage regulators, and we tried

rectifying them but could not do so immediately. We then decided to use an already tested

power supply unit obtained from a scrap computer. The gear systems for the joints were

coupled with the motors and mounted on the fabricated robot arm. Then control and power

lines were drawn from the motors and connected to the control circuitry. A test code for

testing the movement of each joint was developed in which we tested control of each of the

joint motors, and the system test was carried out.

xliv

5.7 Prototype Robotic Arm with Mechanical Structure:

Θ2

Θ1

Fig 5.5 Robotic arm with arm lengths (L1, L2) and Rotation angles (θ1, θ2)

In this robot arm with two degrees of freedom is modeled analytically and forwardand backward direction. In actual robot control system, three 7.5° stepper motor are used andcontrolled by a PIC Microcontroller.

ARMLENGTH(L1)

300mm

FIXED BASE

STEPPERMOTOR1

LENGTH (L2) 250 mm

CONTROL SWITCH

STEPPERMOTOR 2 STEPPER

MOTOR 3

xlv

CHAPTER VI

RESULT AND DISCUSSION

6.1Introduction:This project is to design the stepper motor controller unit axis movement control.

The type of stepper motor that used in the automation system is Bipolar and Unipolar

stepper motors. Besides that, the focus of the project will be on drive the movement of

Robotic Arm 7.5 degree per step. In addition, the arm rotate is forward and reverse with

same angle which is 7.5 degree. The Robot arm is controlled by microcontroller with control

switch.

6.2 Result Analysis:The results were as follows:

The gripper motor turned satisfactorily, clockwise and counterclockwise. But the

movement force was observed to be quite low.

The elbow motor was

successfully controlled.

The base motor was successfully controlled.

6.3 Future Scope:As for the future work, first of all we can implement the sensor less technique using a

faster micro-controller. For example, we can use PIC micro-controller which is specifically

designed for motor control applications. We can also implement the fuzzy control technique,

neural network control, active disturbance rejection control, or other optimized control

techniques to control the motor speed. Another option would be to implement particle filters

or other non-linear filter techniques to estimate the winding currents. Finally, we could

implement the extended Kalman filter with online computation of the Kalman gain by

switching to hardware based filtering, or a faster micro-controller.

6.3 Conclusions:In this paper, a robot arm with four degrees of freedom is modeled analytically and

forward and inverse kinematic are analyzed simulation is generated. Movements of the actual

xlvi

robot arm are executed by 7.5° stepper motors controlled. Since the observation of robot

movements is important before the implementation of actual system in order to prevent from

possible environmental hazards, a simulation environment with control programming is

prepared by C++ programming language with its I/O assembler routines. The simulation and

control program prepared is applied to a manipulated robot arm and any kind of movements

within the limits of arm lengths are obtained. The robot arm is designed to have circles or

arcs drawn. It’s may carry small loads from one point to another point. As the actual robot

arm is aimed to be a prototype made of mostly wooden, the problems occurring from

mechanics like over-weights, sudden change of arm positions, etc. are not considered. When

the system is to be modified for another system like a large robot arm, the new parameters

must be considered in the control and simulation program and I/O board. The parameters are;

a) Degrees of freedom

b) Lengths of the arms

c) Rotation angle of the stepper motors

d) Addresses of I/O board

e) Feedback system

f) Sensing system etc.

Future experiments could include an actual robot arm mechanics rather than prototype

designed by mechanical/Electrical engineers. It could substitute a worker in industry or be

used in education as a demonstration tool.

For any more information,Please mail us …………..

Group--9a) biduyat@gmail.comb) makhon_eee@yahoo.com

xlvii

REFERENCES:

[1]. Muhammad Ali Mazidi , Rolin D. Mckinlay,”PIC Microcontroller and Embedded

Systems” 1st edition, Pareson Education Publishers, Delhi 2008.

[2]. David Benson, ‘’PIC’n Up The Pace”, version 1.1, Square 1 Electronics

Publishers,U.S.A.1999

[3.] Nigel Gardner, “PIC micro MCU C”, bluebird Electronics Publishers, U.S.A.2002

[4]. Muhammad Ali Mazidi, Rolin D. Mckinlay,” The 8051 Microcontroller and Embedded

Systems”2nd edition, Pareson Education Publishers, U.S.A.2008.

[5]. Martin P. Bates,” Programming 8-bit PIC Microcontroller in C”version 1.1 ,Hastings

College, U.K ,2007

[6]. D. W. Smith, ”PIC in Practice” 2nd edition, Newnes Publishers, Great Britain 2006

[7]. Mair, M. Gordon,” Industrial Robotics”Prentice Hall Ltd, UK, 1988

[8]. Website www.ieee.org