

Jean-Philippe
Van Damme

Koen
Simoens

Email:
melexis.trophy@jiepie.com
Studies: Burgerlijk Werktuigkundig-Elektrotechnisch Ingenieur, optie
Lucht&Ruimtevaart, 2e ingenieursjaar
Hobbys: Sportvliegtuigen, Paramotor, Telegeleide vliegtuigen en Helicopters,
Motocross, computeren/programmatie
Persoonlijke website: http://www.jiepie.com
Adres: Ransuildreef 16, 2900 Schoten
Telefoon: 0486/55.43.64
Email:
melexis.trophy@simi.be
Studies: Burgerlijk Ingenieur Computerwetenschappen 2e ingenieursjaar
Hobbys: klassieke muziek, karate, uit eten
Websites: http://www.fitenfight.be en http://www.simi.be
Adres: Wittepoortstraat 15, 8600 Diksmuide
Telefoon: 0496/55.50.81


On Sunday april 25th, the
Melexis Safety Trophy takes place in the Brabanthal in Leuven, Belgium.
More than 40 teams of engineering students and hobbyists have created
their own autonomous robot (without remote control) to take part in
this annual international robot competition. The robots will compete
for the Melexis Safety Trophy and prizes worth € 15.000. Technopolis
will also be taking care of some extra events ensuring educational fun
for young and old.
Everyone is invited to this
competition and access is free.
The challenge consists in
developing an autonomous vehicle that works its way
through an obstacle course by means of intelligent sensors. The track
resembles a real traffic situation, including road markings, obstacles,
traffic signs and other vehicles.
On Sunday april 25th, the
Melexis Safety Trophy takes place in the Brabanthal in Leuven, Belgium.
More than 40 teams of engineering students and hobbyists have created
their own autonomous robot (without remote control) to take part in
this annual international robot competition. The robots will compete
for the Melexis Safety Trophy and prizes worth € 15.000. Technopolis
will also be taking care of some extra events ensuring educational fun
for young and old.
Link to the Melexis
Trophy website.


Here are some of the components
we have used for this project:

The OOPic-R microcontroller
is the brain of our robot. It can be programmed using Visual Basic,
Java or C language. The hardware control method is completely object
oriented, which made this controller more attractive than competing
models. The optional EEProm module allows us to store more than 32,000
instructions for execution at about 2,000 instructions per second.
We also have 32 input/output lines, which can be configured for either
analog or digital signals. The I2C port allows another 128 devices
to be connected, including other OOPics.
http://www.oopic.com


For the visual recognition
of the tennis ball, light beacon and signs, we have selected the CMUCam
vision sensor, which will be mounted on a pan & tilt mechanism,
actuated by 2 R/C servo's. This camera can be connected to the OOPic's
serial port and allows us to track preset color blobs as well as return
color information in certain image regions. The camera has many other
functions which we will not be needing.
http://www-2.cs.cmu.edu/~cmucam/
Instead of using a stepper
motor or a motor feedback to keep track of the beacon's relative direction
from the bot, we have chosen for a simple electronic compass, attached
to the controller's I2C line. This way, we only have to scan for the
light beacon a discrete number of times during the race. Early tests
have shown that the compass's reading isn't affected much by motors
or other nearby electronics.
http://www.robot-electronics.co.uk/shop/Compass_CMPS032004.htm
We purchased 3 ultrasonic
range finders (Devantech SRF04) to locate obstacles near the robot.
These use 2 digital lines each: a trigger line, to send out an audio
pulse, and a return line, which becomes 5V when the echo has been
recieved. Simple mathematics allow the distance to be calculated from
the travel time. To reduce I/O line usage, we have connected all three
triggers to the same output line. These rangers seem quite accurate
and sensitive. A viewing angle of over 45° has been obtained with
each module!
http://www.robot-electronics.co.uk/shop/Ultrasonic_Ranger_SRF041999.htm
A very simple line detector
is used to make sure the robot does not cross the silver foil that limits
the running area.
Two of these Lynxmotion
GHM-04 gearhead DC motors will drive our robot on it's two main wheels.
The maximum rotation speed is about 175 rpm, which is plenty with
the wheels we are using. These motors easily deliver the torque we
need to accelerate our robot to its nominal speed. To regulate the
speed of rotation of these motors, we need a dual channel H-Bridge
(Lynxmotion DHB-01) that gets it's power from another, much bigger
battery. This way, motor and electronics power supplies are completely
isolated from each other.
http://www.lynxmotion.com
While the mechanical aspect
of the robot is nearing completion, a lot of work still remains: extensive
testing of all our sensors (especially the CMUCam module), and coding
a small, slow processor with only little memory. We have not yet worked
out the details on how we will approach the given problem as a whole.

Home
Copyright
2004 Jean-Philippe Van Damme
From Melexis we have received
a few sensors, including the MLX90601CKA, which is an infrared thermometer
module, which measures an object's temperature from a distance. These
modules can be interfaced either using a serial data protocol, or
analog voltage output 0 - 5V. We need this thermometer to differentiate
hot and cold soup cans, as the hot cans may not be knocked over.
http://www.melexis.com
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