Let's Make Robots!

Multifunctional Tank 01

TV remote, Follows line, search the target, move objects
Old version - Line following - part 13.09 MB
Old version - Line following - part 21.28 MB
Old version - Object manipulation1.55 MB
Old version - Find the target and bring home2.53 MB

Hi all,

I renewed my old robot. I upgraded its software in order to act more reasonably.

I detached compas, odometer and fix-distance IR sensors. They were unnecessary to find the target and bring it home.

Target is found by laser-finder in combination with ultrasound. Orientation of robot is now "memorised" from previous maneuvres. This is not very precise, but for short tasks like this it is sufficient.


Also I finetuned the gripper sensors which are "mission critical" on order to see if the target is really "in-front" and "in-between" the jaws. Before it happens that robot only sticked into the targe without catching it. Now, based on signals from jaw tip sensors it centers the position and tries to catch the target at low-center position.

What I did not solve perfectly is the way back. Way forward is divided into three separate pieces. To calculate how to go back home I used too simple algorithm. The preciseness of final home position is worse than +/- 10 cms.




Full view

From the back

Clamps powered by 2 servos. Max object width id 60 mm.

Power station. Stabilisers 3,3V 1A,  5V 1A,  5V 2A for motors.

8x2 LCD - shows the mode of operation


IR TV remote board at top. Below - inside wirings

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Excellent job! Lets see some video :)

Hmm the pictures didn`t show the first time I looked.

I will post a video when the robot will look nicer. Now the third Picaxe is still on breadboard placed on top (not shown on the pictures). It does not allow to show all the functionality at the same moment.

I added rest of pictures 5 minutes later. 


The gripper looks very powerfull. Is it home made?


Yes they are homemade. I used aluminium profiles (available at hobbyshops) square shape 10x10 mm for parallelogram and U-shaped 12x10 for jaws and mount. The squared pieces fits perfectly inside the U-shaped ones which simplifies the construction and makes it very strong.

The main power of jaws depends on the servo used. I expect to manipulate with light objects so i used only micro servo but with metalic gears to prevent their damage in case of unpredictable moves.




I'll wait the video to add the two missing stars to  the rating! :-)

I posted details in Tips/WT section

Nice job... i'm so interested to laser range finders... can you explain how it works please?




Very nice job! I like your metal construction. It's really nice to meet someone from the Czech republic there - I thought I know a lot of mobile robotics enthusiasts living in our republic :-)


Could you please add a video?I am interested in tank based line followers since I know what probles the tank based system brings. Why have you decided to use three microcontrollers for one mobile robot? Wouldn't it be better to use one "bigger" MCU?


EDIT: One more question: How did you make the odometer?

After several attempts I decided to use mouse scrollwheel with mechanical encoder. It gives only two pulses per cm which allows to count them easilly. I use only one odometer for the distance. Direction is measured by compas. Software is still under development.



Very nice, i like the fact that you started small and then add few stuff, and then add again, and then add again... until you have a first robot that you can be very proud of!