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  • Author Author: ipv1
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Self Balancing Robot - Temporary Diversion from the Quadcopter Project - Demo

ipv1

Abstract

As most of you know, I am doing a quadcopter from scratch project where I make almost everything from scratch. In doing so, I had to understand the dynamics behind the software/firmware and in order to explain the quadcopter, I can start by explaining a balancing robot. In this post, I explain the build and provide a video demo for the robot. Lets go!

 

The build

I usually build stuff from scrap and recycle what I can and this project is no different. I start with some scrap wood and made a simple box like frame. I trimmed off wood from the sides to reduce weight and to make it a little more presentable. Finally I added some paint and a quick and dirty job later, I have a robot frame.

IMG_20150411_201416.jpg

As you can see, in the above pic, I have some motors and wheels attached as well. I bought the wheels a long time back and the motors were purchased online. These motors are 288RPM 12V rated and have optical encoders so that we can track the distance moved by each wheel. I clamped these motors in place using some sheet metal pieces I cut up from the scrap tin boxes I had. You can use soft-drink Tins etc as a source of the sheet metal and self threading screws to attach them to the wooden base.

 

In order to drive the motors, I am using an L293D motor driver which came from an older robot which lost it's wheels in an accident. image

Since we need a place to put the control board, I used a cardboard box and cut out an H shaped plane to sit atop the motor driver floor. The control board itself if an Arduino Uno which I received as a part of the Internet Of Holiday Lights Challenge from Element14 and I made a shield for the MPU9150 breakout board. The image below shows the same shield but on the FRDM K64F board which I was using for the quadcopter.

IMG_9611.jpg

I scraped together some libraries from the internet for the MPU9150 as well as PID control and a few hours of head scratching later, it actually worked! The video below shows the working robot in action.

I had some failures along the way but it was quite easy and only a few hours of work once you know what you are doing. In the next post, I will be sharing some more details on the code as well as things that you need to consider when making one yourself.

 

Cheers,

IP

  • in reply to shabaz

    Hello sir,

    It actually came out better than I though and it took me only a few hours on the weekend! This one is based on the arduino and I have a similar setup on the FRDM K64F that Dr. Defeo sent us(IBM kit). The eCompass demo works quite nicely and is quite stable using the on board sensors but I could not make it work with the MBED system and external I2C sensors.(Some issue with mbed- yuck!) and due to these instabilities I do not want to use it for my quadcopter. I experimented a lot and as a result I would prefer an arduino possibly. I am experimenting with KDS but progress is very slow. image

     

    As for the wood, I have a lot of scrap lying around and my Cel Robox just went back to the UK so it seemed like my only option image

     

    More coming soon.

    Cheers,

    IP

  • Hi Inderpreet,

     

    Wow, very nice!!

    It seems very stable. And well made!!

    I can see that this would be a good platform to test out some of your plans for the quad-copter safely.

     

    Wood is one of my favourite materials to work with too - don't see enough of it in technology projects!!

  • Hi all,

    Thanks for the positive comments.

    John Sir - To be honest this post was a toe dip to see if there is any interest in the subject. I have some interns producing some content that can use useful in understanding self balancing robots and possibly make a segway! I will definitely be posting more details about the build, theory and practice since there is much to be learned and also as I found out the hardway that there is no single place where this system has been discussed from the point of learning. More will come soon.

     

    Dimitrios sir - If there is anything sepcific you would like me to discuss, please do let me know.

     

    Neil Sir - I initially forked the code from a Mr. Franko who has done a similar project and the code is available on my github at http://github.com/inderpreet HOWEVER the code was not completely documented nor did it work out of the box for me. I made changes in a branch on my local machine which I will merge and push once I finish commenting properly. You are welcome to the existing code if you would like to experiment.

     

    cheers,

    IP

  • Hi ,

     

    Very impressive. I look forward to seeing some details of your code.

     

    Neil