Introduction: The Building of Q.T.Pi : an Autonomous Sumo Robot

About: We are a home school group that has created a robotics team with 6 members involved in the team. We do several shows with a local Collage that has won IGVC several years ago. We mostly build sumo bots.

Do you want to learn how to build a robot?

This Instructables will tell you how we built our 20lb (9.07185 kilograms) Autonomous
Sumo Robot.

This is how we started with building sumo bots. The local college that holds the annual Sumo Bot competition
doesn’t have that many rules except the 20lb weight limit, no dangerous weapons
and it has to stay on the board.

We first started building our robots with The Lego Mindstorms system, I would highly suggest this product for getting started.

But we wanted to do more than the little Lego robots and started to work on a heavy weight robot.

So that's how we started working on Q.T.Pi.

Step 1: Getting Started on Q.T.Pi.

Things you’ll need:

Arduino Uno -

A bread board - the kit above has one

Two Parallax HB-25 Motor Controllers (or you could Use a Sabretooth Motor controller but
this is much more expensive) -

Parallax QTI sensors -

11.1, 3c Lipo Battery-

3 pin Ultrasonic Sensor -

Motors- We took our motors from an old power wheel kiddy car.

Wire- Any hardware store- or Radio Shack has this item. ______________________________________________________________________________

The rest is up to you, what kind of design do you want, what do you want to make chasse out of, do you want a weapon? Do you want two wheels or more or even tank treads, how many sensors do you want?

We decided for Q.T.Pi that we would have a wooden frame so it would be light, a plow on the front to get up underneath the other robots and two wheels for turning quickly.

Step 2: The Building of Q.T.Pi

My Dad built the frame because I’m terrible at working with wood. He also made the blade on the front of the robot. We had to do all of the wiring, programming and taping by ourselves.

We had to split the five volt pin out to five different pins one for each Motor Controller,
one for each QTI Sensor and one for the Ultrasonic Sensor. We could have used a Proto Shield but we weren’t thinking about using that (I would use a Proto Shield if you decide to do this project).

We did the same to the ground. If you use a metal frame you could mount the ground on the
frame, or you could do what we did and branch off the five volt on a bread board.
First, we hooked up the pins on the Motor Controllers to the Arduino.

The HB-25 Motor controllers use the same signals as you would do with a servo motor there’s
plenty of info on the Parallax website. (Link below)

Then we hooked up the wires coming from the motors to Motor 1 and Motor 2 on the HB-25 board.

Next, the Lipo battery to the positive (+) and the Negative (-) Leads.

After that, we ran a test program which is also on the Parallax website.

Then, we started on the QTI sensors, these work on digital pins on the Arduino. They also take 5v’s and of course a ground.

We hooked them up and ran the test program which is also on Parallax website. (Link Below)

It should read different values if it’s Black or white.

And finally the three pin ultrasonic sensor, this also goes on a digital pin on the Arduino.

We used a 3 pin instead of a 4 pin because it’s easier to program and you have one less wire to worry about coming loose.

Step 3: The Programming of QT-Pi.

The QT Pi program logic is fairly simple. It initializes all the variables, waits five
seconds (actually 3 seconds, the Arduino takes 2 seconds to start), and starts
looping the main program. The main program checks the color sensors, than the ultrasonic and either charges, continues going forward, or it backs up and turns. After it has completed those steps it just loops again!!! The only
unique thing that was added was a random turn time. This is so the robot won’t get stuck in corners.

We also attached the full program file for you, with the latest version.

Step 4: Conclusion

We had a ton of fun doing this project and learned a lot too.

We hope this will inspire you to start working and inventing on your own robots with some friends
and family.

We’re working on more Sumo Bots and other projects that might be on here soon.

Please comment if you have any questions

And please vote!!!

Happy building,

From the HEARTH Robotics Team!

Oh by the way, QT Pi won the competition!!!

Here is a video of it being tested:

Robotics Contest

Participated in the
Robotics Contest

Tech Contest

Participated in the
Tech Contest