Project Overview- Strong Arm
ECEN 4610, Spring 2005
Thaine Hock
Matt Corne
Sammit Adhya
Luz Quiñónez
Project Goals

To design and build the controlling electronics for a six-axis
robotic arm that can be controlled through the use of
simple finger motions

Arm will allow paraplegics to control robotic arm in three
dimensions

Proof of concept of a larger scale device and training
system
Adhya, Corne, Hock, Quinonez
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Outline of Approach
Finger
Sensors
FPGA
Micro
Controller
Magnetic
User
Sensors
Interface
Servo
Controller
Adhya, Corne, Hock, Quinonez
Arm
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Finger Sensors

Polar Coordinate Control System
– Push Buttons and Limit Switches
– Six directions of control
– Grip and Release
Adhya, Corne, Hock, Quinonez
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FPGA

Uses Magnetic Sensor as Inputs
– Determine Initial Block Positions

Send Polar Coordinate Position to
Micro Controller Using MemoryMapped Registers
Adhya, Corne, Hock, Quinonez
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Micro Controller

The Brain! Boahahahahaha!!!
– Freescale 68HC912DG128A
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8KB SRAM
2KB EEPROM
128KB FLASH
SCI, SPI
ADC Onboard
69 I/O Pins
Adhya, Corne, Hock, Quinonez
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Servo Controller

Control Six Servos Using Serial
Interface
– Generates PWM signals to servos
Adhya, Corne, Hock, Quinonez
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Arm

Lynxmotion Robotic Arm
– Six degrees of freedom
• Base rotation, shoulder, elbow, wrist motion, wrist
rotate, and a functional gripper
Adhya, Corne, Hock, Quinonez
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Magnetic Sensors
Place Magnets Inside Blocks
 Build Magnetic Flux Detection Grid

– Detect location of block using
triangulation
Adhya, Corne, Hock, Quinonez
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Division of Labor

Finger Sensor
– Thaine

FPGA Implementation
– Sammit

PCB and Micro controller
– Thaine

Robotic Arm Algorithms
– Sammit and Matt

Magnetic Sensor and Block Detection
– Luz

User Interface
– Matt
Adhya, Corne, Hock, Quinonez
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Schedule
Adhya, Corne, Hock, Quinonez
11
Risks and Contingency Plan
Mapping cylindrical coordinates to
servo positions may prove difficult
 Magnetic sensors not sensitive
enough to detect block positions

– Possible use of ultra-sonic sensors
Adhya, Corne, Hock, Quinonez
12
Economic Aspects and
Marketability

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Training unit cost is relatively low
Practical arm cost will be very high
Moderate demand
Possibility of medical insurance covering
some/most of the cost
Approx 7800 Spinal Cord Injuries each
year, many of them could benefit1
1:http://www.sci-info-pages.com/facts.html
Adhya, Corne, Hock, Quinonez
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Sustainability and
Manufacturability

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Parts widely available for control circuitry.
Can be used with many different arms
Effect of component tolerances are low
except for a small handful
Auto-test routines in software
Complies with regulations and is safe to
operate (training version)
Adhya, Corne, Hock, Quinonez
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Environmental Impact
Pros

Cons
Can be mostly leadfree
 No byproducts


Would need large
battery (most likely
toxic)
Consumes large
amounts of power
Adhya, Corne, Hock, Quinonez
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Impact on Society

Full scale device would allow some
handicapped persons to be able to
perform more physical tasks,
qualifying them for more job
opportunities
Adhya, Corne, Hock, Quinonez
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Questions?
Thanks!