R.C. COCONUT HARVESTING DEVICE

USING ROBOTIC ARM

Guided by

PROF. C.P MUHAMMAD(Head of the Department, ME)

SHAZ MUHAMMAD R

Mobile : 9846926008

shazmr369@gmail.com

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Introduction

This is a unique model which will be the machine-front

of the coconut industry of Kerala and in turn will serve

as a great help and boon to coconut farmers in Kerala.

It consist of a ANTHROPOMORPHIC arm.

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Literary review

462 ideas around the nation

109 shortlisted

9 in number is classified

None is efficient as per

specifications put forward by

industrial department.

3

Relevance of this device

For harvesting coconuts in spite of conventional method.

Saves money

Remote controlled

Precise control and user friendly

Avoids the risk of accidents

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System Components

Manipulator

Shoulder

Elbow

Wrist

Power supply

Control unit

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Robotic arm performs the function of cutting coconut’s spike and unnecessary branches.

Three degree of freedom.

This is an electrically driven robotic arm.

Consist of

Actuators

Camera attached to wrist

Motor & gear system

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Base motor (DC series motor)

Specifications

# Supply : 12 V

# Weight: 1650 gm

# Speed : 14 rpm

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Geared motor Specifications

# Supply - 12v

# Torque

T1- 12kgcm

T2- 5kgcm

# Speed - 10 rpm

# Weight

W1 - 800gm

W2 – 600gm

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The controls are done by remote controlled (wired).

A 220V - AC supply is given to the 12 V battery adapter.

components of joystick

• Relay (x 2)

• Push –on switches (x2)

• Toggle switches (x 4)

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Controls 4 toggle switches to select the motor

2 push-on switches to rotate the motor in clockwise and anti-clock wise direction

2 Relays(electrical switches) to compact the wiring system.

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Working envelope of the arm

volume of the hemisphere formed = ⅔Πr3

= 224582.6 cm3

Where, r = Length of wrist +Length of elbow

= 20 cm+27.5 cm

= 47.5cm

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ANGULAR VELOCITY

Angular velocity, ω = 2ΠN/60

For base motor, ω1 = 1.047 rad/sec

For elbow & wrist motors, ω 2 = ω 3 = 1.466 rad/sec

• REDUCTION RATIO

Desired reduction ratio = motor velocity/gear ratio

For base motor = 2.59 rad/sec

Elbow & wrist motor = 0.839 rad/sec

12

Gear ratio

Gear ratio : No. of teeth of Driver/ No. of teeth of driven

Base : 62/35 = 1.77

Elbow : 21/26 = 0.807

Wrist : 21/26 = 0.807

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Design Considerations

To build a arm similar to human arm which can able to stand alone having similar size and not too bulky.

Less cost

Easy machining

14

Selection of arm material

The material used for the arm is taken as Mild Steel.

Its highly durable.

Its light weight in structure.

Can support more load.

Less cost.

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Supporting link with bearings and driven gear

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Link 1 connected to C- clamp

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Geared motor connected with Link 1 using gears

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Basic structure of the arm with link 1

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Dimensions

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COST ESTIMATION Geared motor (12kgcm) : Rs 1500

Geared motor (5kgcm) : Rs 600

DC series motor (14rpm, 12v ) : Rs 600

Bearings : Rs 160 (2 x 80)

Nuts and bolts : Rs 100

Links : Rs 150

Base shaft : Rs 60

Gears : Rs 100

Washers : Rs 18

Miscellaneous : Rs 448

Manufacturing cost : Rs 1880

Total = Rs 5616 /-

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Weight Of The System

Base plate + attachment - 2650gm

Link 1 - 1900gm

Link 2 - 1500gm

Total - 6050gm

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Advantages & Limitations

Advantages Limitations

Easy to perform the operation

Compact system

Easy to attach to a climbing unit

Skilled operator is required

Limited payload

Friction at joints

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Future modifications

• A rail to rotate the system around the trunk

• Climbing unit

• Project can be further improved by multidisciplinary project involving electronics, electrical and computer science.

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References INDUSTRIAL ROBOTICS (MIKELL P. GROOVER) TATA McGraw-

HILL

BUILD YOUR OWN ROBOT (Lunt. K) AK PETERS Ltd. 2000

THEORY OF MACHINES AND MECHANISMS (Joseph Edward Shigley)

http://people.csail.mit.edu/etorresj/robot-obrero/

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