Let's Make Robots!

B.bot ( Eurobot cup )

Move objects with his arm
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This robot is destined to the robotic cup Eurobot ( http://www.eurobot.org/ ). It's a great amateur robotics contest composed essentially of students teams or independents clubs. The robot must be totally autonomous. He have 1'30'' to find and move a maximum of objects in a goal.

B.bot is composed of two friends who made all the conception and the realization of this project. And we have also the support of a mechanical teacher who help us to build the structure

The robot is composed of different parts :

 -> A wheel base with two brushless DC motors associated with two independents wheels with high precision encoders for odometry system. This give us a great precision in our movements even if the drive wheels slip.

 -> An arm with two axes of freedom composed of servo-motors to bring diffrents kind of objects.

 -> An LCD panel to show some information about the robots during a match.

A lot of things are still in development. We are actually redesigning all of the electronic boards as Brushless drivers or a capacitive interface for the LCD panel

We have post some information in our blog : http://www.b-bot.eu

Other view of the structure :














And an other one :



The arm :


We are using digital servo-motor AX-12+ from Dynamixel. They are controlled by a common half duplex serial line. A lot of parameter can be programmed as torque, speed, position, etc... This type of actuator are a little bit expensive than analog servo motor.

We have coupling two servo to lift a largest load.

The Encoder :












This is independent wheels with encoder. Very useful for making a good PID controller and odometry system. We have 4096 step in one wheel revolution.














 The motor :













We use brushless DC motor for moving the robot on the table. It's the little challenge of the B.bot team. We wanted making our own Brushless DC controller/driver. Brushless DC motor are very dynamic and powerful, they are a smaller and cheaper than equivalent brushed motor. So we buy in the first time motors and build the robot around the.

Here we are using maxon EC-max 22 motor : 22W 24V with a ceramic planetary gearbox who divide by 20 (if my memory is good)

 The LCD panel











This is our LCD panel controlled by a dsPic. You can saw a small video here : http://vimeo.com/3213133

( sorry for my bad english, if someone would correct me send me a email )

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Your english is better then most Americans my friend. Very nice job on your project too. What is it made of? I'd like to see some close up pictures if possible. And a video of it in action, if you please.
Well built and aesthetic robot! Was there a reason you chose to run brushless motors?

I have added a lot of photo and some descriptions. A video of the arm in action must be post soon.

See you.

Very nice photos of some very nice machining! I like the idea of using independant freewheeling wheels for odometry.

Looks like you've done some nice machining and custom PCB work on this. Thanks for the detail pictures. Your team did a really great job. Can't wait for the video to see it move.


edit: just watched the video of the display, impressive! really liked the "soft" scrolling. if you don't mind me asking what is the music you used in this one? http://vimeo.com/3222365 which is the better video I think.

I don't have mentioned the second video which are made in french (and with a lot of text). But effectively, it's a better preview of the work who was accomplish on the LCD. All the functions are developed to be generic. So I can now print a text anywhere on the screen. A mechanism of overlay offer the possibility of superposing an image above some other element as text or image.

It's a good exercise because I start from zero... I use my own font for the text. The last example with the drawing of line are my preferred. It's more difficult than you can thinking. (But in this moment Wikipedia can help you : http://en.wikipedia.org/wiki/Bresenham%27s_line_algorithm ).

For your question about the music, they are coming from jamendo under the "Creative Common" license. Free to use and download.

In the first movie : http://www.jamendo.com/fr/track/4400

In the second : http://www.jamendo.com/fr/track/57161