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.

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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