PiBot-A

Let's Make Robots Robots
4

PiBot-A with Model B+

Thanks for the feedback. With (only) little changes to the chassis it should work with Model B+ immediately.

5

Time to build

The most time consuming (about 20 hours?) task was to build the very compact chassis. (I’m not a mechanic and don’t have professional tools.) The software was easy to write. From installing the Pololu python library to making the bot some obstacle avoiding it took me 20 minutes :slight_smile: Just a few lines of python code, see robot-rt.py in the tarball that can be downloaded from my website.

6

No kidding I want one.

Where can I get one like seriously?

7

Want what?

Sorry - don’t know what you mean :o)

8

Great project, klasse Arbeit

Great project, klasse Arbeit :-) I like the compact build with no wasted space.

I just checked your website and think you should write some of it here too, you know that besides me and a few other German speaking dudes the most of the guys here using google translate and that’s not really a reliable tool.

9

Sorry are these for sale?

Are these being sold?

10

Mosmas made it

Mosmas made this robot as a personal project (I am assuming, please corect me if i’m wrong). The best way to “get one” woud be to follow his build instructions on his blog (http://www.retas.de/thomas/raspberrypi/pibot-a/)

 

Allowing for google translate errors, I found the instructions amazingly complete and easy to follow.
Enjoy ;) 

11

Now I got it :wink:

No, it’s not for sale. I made it by myself. I published a very detailed description with lots of photos on my website, unfortunatelly it is in German, because my English is rather poor. Next weekend I will write some hints for those who want to make a replica on this page. For now maybe this may help to rate the efforts for building it:

  1. The basic hardware (Raspberry Pi, Pololu module and motors) is plug & play.
  2. The basic software (which makes the wheels rotate) is already part of the Pololu kit.
  3. The additional software that I wrote is very simple and can be downloaded HERE
  4. The actual construction described on my website is pretty difficile and you have to work very meticulously. See photos.
  5. A complete shopping list for all parts is provided HERE

Summary: If you consider not to clone my very compact construction it should be rather easy to build a bot like this.

12

Google translate

Thanks! I hoped that it would be helpful despite of the errors.

13

Yes I should, …

… next weekend I will write some hints for those who want to make a replica on this page.

14

Want what?

Sorry - don’t know what you mean :o) [wrong place for this reply - see below]

15

very nice

very nice…love the compact design. :]

16

Done.

Hope this helps.

17

One of the reasons I like
One of the reasons I like large bots is because my mechanical skill usually isn’t up to making the wonderfully compact case like you did. So I just make it 12 inches in diameter and I can fit pretty much anything I want. :slight_smile:

Though yours looks better.

I’d congratulate you auf Deutsch, but my German is over 25 years old. I wish I had kept it up.

18

Vielen Dank
Vielen Dank for your kind words :slight_smile:

19

UPDATE

I added a video, some photos and information about the line follower mode.

20

Nice track (and music track

Nice track (and music track too :slight_smile: ).

I take a look in the code (clean and simple too) and +1 for encrypting name of this site into:

(L, M, R) = read_sensors()

I have one question, how do you achieve behaviour in the dead end of line? (The one in the right side of video, without black disc). I would expect the robot will continue straight to try to find corrupted line, but it turn back. Thaks.

21

LOL

(L, M, R) - didn’t notice that yet :wink:

“I would expect the robot will continue straight to try to find corrupted line” - me too :wink: I tested different length of the dead end: when the straight piece of the track is a little bit longer it behaves as you (and me) would expect. Currently the robot still has a little left twist when reaching the dead end, and I thought it was a nice alternative to the “railway switches”.

22

Maze Follower

I added a video of the “maze follower”, which is just a pre-study for the maze solver.

The peculiarity of my solution could be that I use only 3 sensors (rather than 5 or more, which seems to be usual). Notice that the robot is swaying a little bit whenever it reaches a node of the maze. It then looks to the left and the right to see whether there is a black line forking, a crossing or a T-junction. That way it compensates the absence of the outer sensors that are typically used for that purpose.

The timing is very crucial: it makes a big difference to drive some hundredths of seconds when the battery voltage is going up and down. Hence the robot starts with a 180° turn to the left and right and back for a calibration (see video). The time needed for this is measured and is taken into account when calculating the time for some particular movement.

For now the software only implements the left-hand rule, and the maze is pretty simple. Once it is finished, I’ll publish it here.

23

Software of maze follower

The software for the maze follower is here: robot-mf.py.

The calibration is still experimental. It works pretty well with fully charged batteries, when the battery voltage is going down, failures tend to occur more often. The video above was made with this code and full batteries :wink: