Mahdi Jadaliha
Introduction
To estimate position has always been a
challenge for the mankind, be it navigating
spaceships using
I
nertial
N
avigation
S
ystems
(INSs), or simply crossing the desert using
compass or stars to find his direction.
Different applications call for different
methods, however, the main goal is the same
in all navigation: to estimate or measure
position or some of its derivatives.
Problem Definition
I have been several years in a
r
obotic team. My duty was
finding position of robots and obstacles.
since an INS refers to no real

world item beyond itself. It is
therefore self

contained, immune to jamming and
deception, non

radiating, and a good candidate for position
estimation in Autonomous Mobile Robots.
Problems with INS
Can’t measure speed directly
Can’t measure yaw directly
It is very dependant to temperature
* please refer to
http://en.wikipedia.org/wiki/Inertial_na
vigation_system
for more information.
Solved with Dodecahedron
Can measure speed directly
Dodecahedron calculates speed by measuring gyroscopic
torque on different facets.
Can measure yaw directly
advanced compassing mechanism is developed to estimate
the position of magnetic source(by scattered
measurements on the surface of dodecahedron) , therefore
we can find magnetic field of earth even in a complicated
environment.
It is not very dependant to temperature
measuring quantities with two sensors in opposite direction
reduces the effect of temperature on their biases
effectively.
I have DONE every steps of this
project by myself
Designing Micro controller and analog circuits
by
Altium
(
Protel
)
Designing PCB board by
Altium
(
Protel
)
Soldering
Programming Microcontroller by C (MPLAB)
Programming data accusation software on PC
by Delphi
I tried 3 times to make best
measurements
Main component of IMU modules
Each modules is a
complete
I
nertial
M
easurement
U
nit
(IMU). It has 3
perpendicular
axes of
measurement for
Accelerometers
and Gyroscopes.
Each module
(pentagonal) has
capabilities equal
to
Xsense
commercial
Products.
(
http://www.xsen
s.com/
)
However I designed this
Dodecahedron for Autonomous
vehicle, the modules can be used
in different configuration for
different propose.
Motion Tracking is one of the most
popular use of these modules.
Motion tracker
* please refer to very exciting Video
http://www.moven.com/Static/Docume
nts/UserUpload/Moven_movie/product_
reel2009.wmv
for more information.
From: www.xsense.com
Dodecahedron Hardware complexity
It is made from 770 discreet electrical component
Measures 108 Sensory Quantity
It uses Distributed Processing with 12 DSP
Support RS485, RS232, SPI, CAN to communicate
Advanced Data Structure to reduce communication
faults
Manage all process by Interrupts in an event trigger
manner to reduce power consumption
Uses DMA to decrease process load
Geometrical shape
Appendix: Platonic Solids
Name V F E F

Type Truncation Dual
tetrahedron 4 4 6 triangles truncated tetrahedron
tetrahedron
cube 8 6 12 squares truncated cube
octahedron
octahedron 6 8 12 triangles truncated octahedron
cube
dodecahedron 20 12 30 pentagons truncated dodecahedron
icosahedron
icosahedron
12 20 30 triangles truncated
icosahedron
odecahedron
tetrahedron
cube
octahedron
dodecahedron
icosahedron
All vertices, edge mid

points and face mid

points lie on concentric spheres
All faces are the same shape and are all regular polygons
Thus all edges are equal in length and face corners equal in angle.
Duals are also all
Plationic
Solids.
The cube is also called a hexahedron
[1] http://www.cit.gu.edu.au/~anthony/graphics/polyhedra/
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