ME- 362
Instrumentation and Measurement Sessional
A brief look into “ THOR ”
or the “ Terrain Hazard Optimized Robot”
Presented by Group A 15
Roll No
0510005
0510014
0510024
0510033
Student Name
Naser Imran Hossain *
Md. Rokanuzzaman Khan
Prajnaprasun Bhattacharjee
Nahid Pervez
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Presentation Overview
Introduction
Objectives & Features
Mechanical orientation
Circuitry
Purpose
Critique
Optimization & Future plans
Conclusion
Acknowledgments
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Introduction
Since Karel Capek (1890-1938) first used the word
‘robot’, man has been infatuated with the creation of
mechanized companions.
Our project was named after the Norse god Of thunder
who use to banish evil to their demise. For it too might
one day help humanity in its struggle against the evils of
pollution and contamination.
Our inspiration was the brave remote neutralization of a
possible catastrophe by one of our hon’ teachers when a
jammed Co-60 source of the γ-beam irradiator at
Bangladesh Institute of Nuclear Agriculture (BINA)
threatened the lives of many in the late 80’s.
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Attendees
The Project - “ THOR ”
The team
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Objectives
Manually maneuver into hazardous environment.
Avoid obstacles and detours on the way using fast
directional control.
Grip mission objectives with link-driven gripper
Bring objective back into safe containment area and
deposit.
Sense heightened level of temperature or lack of light on
due process and indicate.
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Features
Custom designed “ Gripper Arm ”
Multidirectional “Pseudo Holonomic” Control.
Smart ‘ Ambient ’ light and heat sensing.
High torque driving mechanism for heavy payloads.
Minor object avoidance.
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Mechanical Orientation
Gripper Arm
Part 1: The “ Grip ”
Acrylic made to reduce weight.
Wire manipulated.
Maximum jaw clearance 8mm.
Spring operated auto recoiling.
Designed to always assume a vertical
position during operation.
Gripping control by gear-motor.
Fig : The Grip
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Mechanical Orientation (cont)
Part 2: The “Arm”
Consists of 4 acrylic links in total
Supports the vertical positioning of the
grip/claw.
Counter supports each other in cases
of heavier payloads.
Arm leverage and height controlled by
wires and a gear motor.
Fig: The Arm
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Mechanical Orientation (cont)
Navigation Strategy
Part 1: Hardware
Separate gear motors control
individual wheels, crane fulcrum
and gripper.
Polarity is changed instantaneously
with DPDT switches.
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Mechanical Orientation (cont)
Part 2 : Mechanics
Both wheel rotate in common
directions to go forward or
backward.
To ensure Pseudo-Holonomic
movement, motors are
coupled to the forward wheels
only.
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Mechanical Orientation (cont)
RW rotates opposite to LW to change direction and
vice versa.
Smooth turns are made possible by stopping one of
the wheels and resuming the other
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Circuitry
Part 1: Overview & Functions
LDR senses lack of light and indicates with a Green LED.
NTC-Type thermistor senses increase in temperature and indicates
with a Red LED
Possible to calibrate sensors according to ambient variables.
In circuit “ Operational Amplifier ” ( LM-324 ) synchronizes between
sensor feedbacks and indicators.
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Circuitry(cont)
Sensing lack of light
– Under full incident light (spectral range of 515 nm ~ 730 nm ) , LDR,
with its decreased resistance, renders the path to the LED inactive.
– In darkness, its resistance increases. Op-Amp compares the
feedback and lights up the green LED.
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Circuitry(cont)
Sensing heightened temperature
– Under increased temperature, the NTC type thermistor resistance is
decreased rendering it inactive in the circuit. Op-Amp again compares
the feedbacks and lights up the red LED.
– When ambient temperature recedes to normal, the resistance increases
cutting off power supply to the LED.
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Circuitry(cont)
Part 2: Logistical Consideration
Over the range of -50°C to
150°C, NTC thermistors offer a
distinct advantage in
sensitivity to temperature
changes compared to other
temperature sensors like PtRTD.
Thermistors are also easily
available and relatively cheap.
Fig: Resistance Vs Temp
Graph
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Circuitry(cont)
Light Dependent Resistors
(LDR) provide a
comfortable range of
resistive outputs to work
with.
Like the thermistor, LDRs
are also easily available
and relatively cheap.
Fig: Resistance Vs Light Intensity
graph
Variable resistors are used
to calibrate circuit in
contemporary environment.
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Purpose
THOR at its infancy, is but only an engineering project.
However with proper planning it maybe employed in a
variety of useful purposes:-
Reconnoitering through possibly radioactive or hazardous
environment.
Salvage mission over terrains unsuitable for human
exposure.
Charting terrain as a drone for possible thermal leakage ,
heat flux and variation is luminescence.
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Purpose (cont)
Animation showing THOR’s dynamic movements
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Critique
Acrylic parts are vulnerable to sudden shock-loads.
The wiring of the motors and DPDT switches often
breaks loose.
The bead type thermistor is not as well responsive as the
LDR. So the signaling might be delayed
The wires used for gripper and arm-control is not that
strong in tension and might sever under heavy payloads.
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Optimization & Future plans
How to Optimize the current configuration?
Replacing acrylic parts with stronger materials, like HDPE (High
Density Poly Ethylene) or Aluminum.
Integrating radio frequency control and servo drives.
Incorporating solar-power for prolong operation.
Automating directional commands via microcontrollers.
Replacing LDR with more sensitive sensors such as
phototransistors.
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Optimization & Future plans
What prospect does THOR’s future hold?
Application in humanitarian services like minesweeping,
scavenging battle debris.
Stellar and interstellar explorations.
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Conclusion
At the end, we can only hope that we were
able to achieve what we set out to do at
the beginning of the course. We learned
much throughout the semester, about
mechanical and electrical components and
most importantly about human resource
management. However, all in all that was
quite a delightful experience.
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Acknowledgments
For the completion of our project, we are greatly indebted to the following persons.
Without their guidance, it would’ve been impossible to go through such an endeavour.
Dr. M.A. Taher Ali.
– Professor, Dept. of Mechanical Engineering
A.K.M Monjur Morshed
– Assistant Professor, Dept. of Mechanical Engineering
Md. Wasim Akram
– Lecturer, Dept. of Mechanical Engineering
Md. Al Amin Khan Chowdhury
– Lecturer, Dept. of Mechanical Engineering
Abdul Motin
– Lecturer, Dept. of Mechanical Engineering
Mr. Masudur Rahman
– Assistant Instrumentation Engineer
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Thank you all for joining in.
Visit
http://project-thor.pbwiki.com
If you have any further queries.
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Q & A session
Feel free to ask
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