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Robot Challenge

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11:59 am
November 17, 2009


tdr

Cyborg

posts 7

Would anybody be interested in entering and going to the Robot Challenge[1] in Vienna, Austria on the 20-21 March. There are a few different events people can enter.

Linefollower

Linefollower Enhanced

Robot Sumo

Puck Collect

Humanoid Sprint Freestyle Exhibition

1.http://www.robotchallenge.org/en/home/


I


6:59 pm
November 18, 2009


David

Admin

posts 134

Sound interesting,


It would be great to get a team together.  How many people do you think you would need? 3 or 4 people?

Split up the tasks 

  1. Mechanics
  2. Electronics
  3. Programming
  4. Thinking of a cool name
I'll put up a post on the main page,when I get a chance, see if it'll drum up some interest.

3:49 pm
November 23, 2009


tdr

Cyborg

posts 7

you would need 3 or 4 it its peoples first robot, I think it woul be best to aim for Linefollower Enhanced and Linefollower.

4:27 pm
November 23, 2009


jiri

Castletroy, Limerick

Cyborg

posts 37

Hi,

I am interested to take part in such a group. When will we start? :-)

I can contribute with programming and electronics knowledge and i agree with you, i am thinking about Linefollower Enhanced.

Problem is that I am living in Limerick, and i guess the base for the group is supposed to be in Dublin. So I would prefer meetings on the weekend


Jiri


5:08 pm
November 23, 2009


tdr

Cyborg

posts 7

I am based in Dublin, my own skills are electronics and programming. I have done some mechanics for robots , that was using lego kit. I would like to see if we can get a team together ,

6:25 pm
November 23, 2009


jiri

Castletroy, Limerick

Cyborg

posts 37

I am going to Dublin on 5th December, so we could meet somewhere (in the pub i suggest)

J.

6:28 pm
November 23, 2009


David

Admin

posts 134

O.k well I'm a mechanical engineer so some mechanical design rubbed off at some stage and I'm fair enough at electronics and passable at programming. I'd be willing to help out in any way. I'm also based in Dublin.


I Added a post to the homepage.

6:31 pm
November 23, 2009


tdr

Cyborg

posts 7

Post edited 6:34 pm – November 23, 2009 by tdr


jiri said:

I am going to Dublin on 5th December, so we could meet somewhere (in the pub i suggest)

J.


The pub is fine if we just want to talk , or we can use TOG if you wanted to do some work

6:39 pm
November 23, 2009


jiri

Castletroy, Limerick

Cyborg

posts 37

I'd like to spend in Dublin the whole weekend, so we could discuss and work too. TOG is accessible during the weekend?

J.

PS. I hope it doesn't matter to be part of Irish robotics team if I am not Irish nationality Wink


6:41 pm
November 23, 2009


tdr

Cyborg

posts 7

Post edited 6:42 pm – November 23, 2009 by tdr


TOG is open 24/7 to members which i am one. I dont think its matters if your not irish. I dont care for one. You like robots thats all the matters :)

7:00 pm
November 23, 2009


David

Admin

posts 134

We'll get you a honorary Irish passport Jiri :)

All nationalities welcome, we can name the team to reflect that. I'll try to keep that weekend free. I'm talking in the Science Gallery on Friday the 4th as part of the ignite talks (http://ignite.oreilly.com/2009…..in-2.html), so if you are in Dublin then we could talk then and work on building something the next day.

7:05 pm
November 23, 2009


jiri

Castletroy, Limerick

Cyborg

posts 37

OK :-)

so where to start?

At the very beginning, as I've already sent to another topic,

but i don't insist on it at all:

Pololu 5″ Robot Chassis RRC04A

Pololu 42×19mm Wheel and Encoder Set

Micro Metal Gearmotors

TB6612FNG Dual Motor Driver Carrier


but for me would be nice if the processor which we use will be AVR or ARM7, programming in C, is it ok for you?


J.


7:15 pm
November 23, 2009


David

Admin

posts 134

I have some motors lying around with built in quadrature encoders, which we could use.

I agree programming in C is best. I like messing around in with Arduinos, but "pure" AVR is fine. I have never used ARM7 but I guess it would be similar.

I'd have to look at the allowable dimensions etc to spec out the platform. In any case, I'm sure we could make our own Chassis.

I'd have a better idea after reading the rules :)

9:41 am
November 24, 2009


jiri

Castletroy, Limerick

Cyborg

posts 37

Nice,

C language, some AVR (Arduino is fine)

David, could you send me the specification for those motors (current for free-run, current in stall) ?

I'm still thinking to have some platform (using components noticed above) simultanelly here, just for testing my part of development, because Limerick is quite fare from Dubllin.

But stay compatible with our main platform as close as it will be possible.

Make it sense?

J.

12:17 pm
November 24, 2009


David

Admin

posts 134

Reading the rules, there isn't much restrictions on the size of the robot (looks like 50 cm, which is massive). I think a small robot makes sense for getting through the tunnel and around obstacles. 

If we are to enter "line following enhanced", I think we might as well enter the "line following" as well and use the same robot (the same robot won both last year).

The motors I got surplus on the cheap, so I'll have to dig out the data sheet. At the moment all I remember is that they are 12v micromotors, but on reflection might be a little slow for our purpose. If you are going to build one also, we can both use pololu motors, they might be a bit quicker anyway.

So the question arises about how much of the hardware we want to make ourselves.

For example http://www.pololu.com/catalog/…..roduct/960 looks ideal for line following, but we could build one ourselves I guess. It really depends if the focus should be on hardware or on the software algorithm. 

1:12 pm
November 24, 2009


jiri

Castletroy, Limerick

Cyborg

posts 37

Focus is to win the competition :-)

Concerning hardware and your question.

I think we should start with any existing hardware and mechanical construction as soon as possible and programming and when we will make decision which processor is the best suitable for our algoritms we will try to build more robust and nice looking robot platform.

I have tried integrated H-bridge Dual Full Bridge Motor Driver – L298N and it is quite easy to use it

Then my suggestion is to use some existing quadrature encoders – not to develop them, just buy, or use yours

Arduino – if you have anyone already, than use it, I'll use some similar AVR board in my "Limerick base" (I think we can still be 100% software compatible)


Reflactance Sensor Array – yes, it looks usefull.

I haven't read the rules, but the line can be broken – do they say how it will continue after the break?

We can simply continue when the break occurs in the same direction and wait for next start of the line? or we will have to look around to find the line in any possible direction?

In this case some web camera would be the best solution, but I know, I am realist

Do you understand? I am sorry, my english isn't perfect at all

J.


1:49 pm
November 24, 2009


David

Admin

posts 134

Rules

The rules of the Linefollower apply. Additionly three difficulties will be integrated in the course.

Tunnel: The line will pass through a tunnel. The tunnel is at least 50cm wide and 50cm high. The challenge is to accurately follow the line and to deal with changing light conditions.

Interruption: On one place on the course the line is interrupted for approx. 10 cm. The interruption wont be placed in a curve, therefore a straight extension of the line will lead to the continuation of the course.

Obstacle: A brick (approx. 25 x 12 x 6,5 cm LxWxH) will be placed on the course. The robot has to drive around this brick to reach the continuation of the line.


1:59 pm
November 24, 2009


David

Admin

posts 134

Yeah that all very clear, your English is perfect and definitely better than my Czech (?) so no need to be apologetic. 

Tunnel:

If you are using IR as your sensors, the tunnel should not effect it much, since you are providing your own light source and filtering out visible light in your detector anyway.The tunnel section would appear to there to make it harder for people using cameras, because of the light levels. definitely possible but I think it is only something we should look at if we have a lot of time left over :)

Interruption

Using an array of sensors would allow you to be more confident that you have reached the interruption (as opposed to wandering off the line). At that point use the encoders  (and/or possibly use a compass) to make sure you keep the same heading and hope for the best :)

Obstacle

We would need some sort of sensor at the front of the robot to detect the obstacle (possibly a sharp distance sensor).

As a first thought I see two options

  1. A wall following algorithm – ie hug the obstacle (a brick I think) until you have made it to the other side.
  2. Open loop- Wait till Obstacle is (say) 10 cm away. Turn Right, forward x cm, turn Left, forward y cm, Turn Left, forward  x cm, turn right and you are back on the line.

With x and y chosen depending on the dimensions of the obstacle (which they give you) and how much clearance you want.

I would have a slight preference for option 2 at the moment, but either or another idea could be better.

On a side note, if we develop two robots we can enter them both. Perhaps one with a more aggressive/risky/faster strategy.

5:37 pm
November 24, 2009


David

Admin

posts 134

Right I've made up a spec for the robot


Chassis: Pololu 5″ Robot Chassis RRC04A

http://www.pololu.com/catalog/…..oduct/1500

**********************************************

Motors: Micro Metal Gearmotors

http://www.pololu.com/catalog/…..ategory/51

(Choose one -Speed more important that torque)

********************************************

H-bridge: TB6612FNG Dual Motor Driver Carrier – http://www.pololu.com/catalog/…..roduct/713

**********************************************

Wheels: Pololu 42×19mm Wheel and Encoder Set -http://www.pololu.com/catalog/…..oduct/1218

******************************************

Sensors:

Reflectance Sensor Array:

http://www.pololu.com/catalog/…..roduct/961

OR

http://www.pololu.com/catalog/…..roduct/960

Distance sensor:

http://www.pololu.com/catalog/…..oduct/1136

and

http://www.pololu.com/catalog/…..roduct/117

*********************************************

Micro controller: Arduino

Options:

  • Standard Arduino

http://www.sparkfun.com/commer…..ucts_id=66

  • or a roboduino

http://cgi.ebay.ie/Roboduino-A…..064wt_1161

  • Another option would be this, which has the motor drivers on board

http://www.yerobot.com/romeo-a…..oller.html

*****************************************************************

Connector type

Breakway

http://www.sparkfun.com/commer…..cts_id=116

http://www.sparkfun.com/commer…..cts_id=115

OR

Polarized connectors

http://www.sparkfun.com/commer…..ts_id=8232

decide on one and use it for everything.

*************************************************************

Power

Motors – 7.4v li-poly battery

Microcontoller – 9v battery

***************************************************************

So that's about the everything we need.  How does that sound? Any suggestions, additions, changes welcome! Laugh

9:36 am
November 25, 2009


jiri

Castletroy, Limerick

Cyborg

posts 37

well,

i'll look at it

Meanwhile, do you have any practical experience with ordering components from US directly? (pololulu for example) ?



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