Microcontroller Based Robotic Arm Control Prototype 3l4s4y

Acknowledgements We started this project with an interest in the field of Embedded System.We wish to express our thanks to many people who have helped during the completion of the project. Firstly, we would like to thank our project guide, Prof. B.N.Savant We are grateful for her kind and encouragement.She has guided us throughout the project, when we were stuck in problems that seemed impossible to solve.Her time-to-time guidance has propelled us towards the timely successful completion of the project.

We would also like to thank Ms.Dhanashree Gawali mam, without her co-operation and time-to-time guidence the completion of this project would have been very difficult task. She ed us througout the progress of our project and kept us in high spirits.

Last but not the least, we thank all the seniors who helped us to make our project successful and journey enjoyable.

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Abstract This report shows the implementation of ‘MICROCONTROLLER BASED ROBOTIC ARM CONTROL”. The motor is controlled by using PIC18F series microcontroller with motor driver L293D/L298N. In this project circuit simulation is done using Proteus software and programming in embedded C is done using MPLAB software. The function of the arm is to position and orient the hand. The full function of the arm rests in the potentiometer. Our work provides important elements that are required to build a simple robotic arm of very high quality. As stated earlier we are making use of the PIC18F4550 microcontroller.

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Contents

1 Introduction

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1.1

Basic Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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1.2

Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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1.3

Motivation

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1.4

Problem Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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1.5

Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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2 System Implementation

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2.1

System Block Diagram and Description . . . . . . . . . . . . . . . . . . . . .

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2.2

System Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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2.2.1

Power Supply Specification . . . . . . . . . . . . . . . . . . . . . . . .

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2.2.2

Secification of PIC18F4550 controller . . . . . . . . . . . . . . . . . . .

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2.2.3

Specification of L293D Motor Driver . . . . . . . . . . . . . . . . . . .

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System Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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2.3.1

Circuit Diagram and Description . . . . . . . . . . . . . . . . . . . . .

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2.3.2

Flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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2.3.3

Softwares Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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2.3.4

PCB Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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2.3

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3 Robotics

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4 System Analysis

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4.1

Issues Faced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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4.2

Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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5 Result Analysis

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6 Application

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7 Future Scope

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8 Conclusion

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9 Component Listing And Costing

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10 References

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Chapter 1

Introduction 1.1

Basic Concept

The basic concept is that the position of the stepper motor is controlled using a potentiometer and a microcontroller. As the resistance changes in the potentiometer a corresponding signal is given out to the motor(driven using a driver IC) via the microcontroller. The system checks whether the previous resistance is greater than or less than the current resistance in the potentiometer. Corresponding to the value of the resistance developed the motor rotates in the clockwise or anti-clockwise direction. No change in resistance will cause the motor to stay in its current state motionless.

1.2

Background

Taking a look back at the history of robot development, a special kind of human-size industrial robotic arm called Programmable Universal Machine for Assembly (PUMA) came into existence. This type of robot is often termed anthropomorphic because of the similarities between its structure and the human arm. The individual ts are named after their human-arm counterparts. In the proper sense of the word, manipulation is the function of the arm. The function of the arm is to position and orient the hand, act as a mechanical connection and power and sensing transmission link between the hand and the main body of the person. Our work provides important elements that are to interface a stepper motor to the PIC18F4550 microcontroller and control its position.

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1.3

Motivation

The main motivation behind our project is construct a robotic arm that can act as an aid to the physically handicapped. It can be used in physiotheraphy to measure the stength the disabled arm. Also it can be used as a robotic device used to diffuse bombs thereby saving human lives both for the bomb squad and innocent citizens. Also the main motivation was also to develop it in a more cost effective way so that it can be used by the masses.

1.4

Problem Definition

To Design, Simulate and Build a stepper motor position control system. Implement the same using PIC18F series controller. A driver IC, L293D and a Potentiometer. Test and Validate the prototype system and robotic arm.

1.5

Objectives

1. To study PIC18F microcontroller w.r.t Architecture, Programing and Interfacing. 2. Simulate and implementation of Stepper motor control. 3. Design, Simulate and implementation of position control.

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Chapter 2

System Implementation 2.1

System Block Diagram and Description

The figure below shows the block diagram of our system. • Controller : PIC 18F series microcontroller. • Driver : L293D • Potentiometer : 10kOhms

Description The block diagram consists of controller, motor driver(L293D),stepper motors. When the resistance is changed by the potentiometer, the inbuilt ADC on the PIC microcontroller converts the analog data to the digital data and sends it to the driver circuit. Then this data causes the coils of the stepper motor to charge and causes it to turn. The code to compare the previous and current resistance was burnt onto the microcontroller using the self developed USB programming board.

2.2 2.2.1

System Specification Power Supply Specification

1. Input Voltage = 230V AC 2. Output Voltage = 3.3V-4.0V 3. Output Current = 80 mA 7

2.2.2

Secification of PIC18F4550 controller

• On chip program ROM-32k(Enhanced FLASH program memory) • High Performance RISC U • Data memory - 1.5k • 16-bit wide instructions, 8-bit wide data path • Priority levels for interrupts • 8 x 8 Single Cycle Hardware Multiplier • Three timers and two Capture/Compare/PWM (C) modules. • Addressable USART module- s RS-485 and RS-232 • Parallel Slave Port (PSP) module • Watchdog Timer (WDT) with its own On-Chip RC Oscillator for reliable operation

2.2.3

Specification of L293D Motor Driver

• Operating Supply voltage up to 46V • Total DC current up to 1.2A • Low saturation voltage • Logical 0 Input Voltage up to 1.5 V (High Noise Immunity)

2.3 2.3.1

System Design Circuit Diagram and Description

Description The figure above is the circuit diagram of the system. In this circuit controller does all the control tasks according to the program. LCD display is interfaced to the controller through port D, motor driver L298N is interfaced to PIC to provide protection to the motors. Switch 1 is acts as a START switch, it controls the working of the system,when it open the whole system get switched off. When sw2 is open the motors run with the 50% duty cycle and when it close motors run with the 80% duty cycle. As soon as sw3 is depressed motor will get stops. LCD display is used to display the speed of the motor in RPM. 8

2.3.2

Flowchart

2.3.3

Softwares Used

1. MPLAB 2. PROTEUS

2.3.4

PCB Layout

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Chapter 3

Robotics The word robotics, meaning the study of robots was coined by Isaac Asimov. Robotics involves elements of both mechanical and electrical engineering, as well as control theory, computing and now artificial intelligence (Selig, 1992). According to the Robot Institute of America, A robot is a reprogrammable, multifunctional manipulator designed to move materials, parts, tools or specialized devices through variable programmed motions for the performance of a variety of tasks The fact that a robot can be reprogrammed is important: it is definitely a characteristic of robots. In order to perform any useful task the robot must interface with the environment, which may comprise feeding devices, other robots, and most importantly people.

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Chapter 4

System Analysis 4.1

Issues Faced

1. Concept, Interfacing, and Coding of PIC18F micro controller. 2. Devicing a proper interfacing between the stepper motor and the Potentiometer. 3. To develop a code for Right-rotate-with carry(RRC) which is not present in C. 4. Programming the Microcontroller to specific changes in the resistance. 5. Finding suitable Driver IC. 6. Controlling the stepper motor to move without jitters.

4.2

Modification

Most of the problems faced was clear out by the seniors and from the project guide. Research and development for the code took most of the time. A fully home grown code was achieved after thorough study of the PIC microntroller specifications and architecture.

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Chapter 5

Result Analysis

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Chapter 6

Application 1. Physiotherapeutic measurement of arm strength of the physically handicapped. 2. Bomb Diffusion as an artificial limb. 3. Remote surgery preforming. 4. Industrial Limb, similar to the human arm. 5. Artificial limb in Space Stations.

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Chapter 7

Future Scope The future of this project has a wide range of modifications and upgradations. The robotic arm can be developed to imitate human like movements in space stations in outer space. Since this arm consists of only a simple analog sensor i.e. the Potentiometer it is cost effective and then can be upgraded to move wirelessly using GSM or GPRS. Alsothis robotic arm can be made with more precise movements so that remote surguries can be performed by doctors for patients at remote locations.

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Chapter 8

Conclusion In this project we have interfaced the stepper motor with the microcontroller and our method allows for storing more programs to enhance more function- ality. From our work, we deduced that in comparison to humans, robots can be made to have a larger and more freedom of movement. They can be very precise in their movements, reduce labor costs, improve working conditions, reduce material wastage and improve product quality. Meanwhile, intelli- gent Control is the discipline that implements Intelligent Machines (IMs) to perform anthropormorphic tasks with minimum supervision and interac- tion with a human operator. This project can be further enhanced to as a multi-disciplinary project involving electrical and computer engineers to work together to create more complex, intelligent robots controlled by the PIC 18F4550 micro-controller. Today’s world demands a faster and a reliable robot, we have achieved the basic task of the arm movement control. With this achievement the robot can be developed to complete the various applications discussed such as medical, surgical, physiotherapeutic, bomb difusal and also to measure arm strength of a disabled or physically handicapped human.

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Chapter 9

Component Listing And Costing Sr No. 1. 2. 3. 4. 5. 6. 7.

Component Name Stepper Motor PIC 18F4550 PIC 18F USB Programming Board Capacitor IC 7805 IC L293D Power Supply

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Quantity 1 1 1 10 1 1 1 Total

Price 120 350 350 50 15 55 150 1300

Chapter 10

References 1. Mohd. Ali Mazidi, Rolin D. McKinlay, Danny Causey, “PIC Microcontroller and Embedded Systems”, Pearson Education,Copyright 2008 2. Website: ”http://www.electronicsforyou.com”

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