Sunday, May 29, 2011

What is a kiwi drive?

     Kiwi drive is a holonomic drive.
     A holonomic drive can instantaneously move in any direction. It does not need to do any complex motions to achieve a particular heading. This type of robot would have 2 degrees of freedom in that it can move in both the X and Y plane freely. Simply put it is omni directional. A holonomic drive is useful for situations requiring higher mobility and lower traction than a standard drive system. Using driver oriented control, joystick mixing, and drive mixing, it requires much less thought to adjusting for various conditions on the part of the driver.

Non-holonomic drive can not instantaneously move in any direction. An example of a non-holonomic drive would be a car. Usually a non-holonomic drive uses Ackerman steering; again, such as a car.

Typically a holonomic drive uses 3 or 4 omni wheels. Omniwheels are wheels that can move in any direction, at any angle, without rotating beforehand.

A 3 wheel configuration would be a kiwi drive. A kiwi drive is 3 omni wheels each separated by 120 degrees each. Typically a kiwi drive is in a triangular configuration. All 3 omni wheels are independently driven.

Society of Robots

Saturday, May 28, 2011

Building a kiwi drive robot - Arduino + bluetooth

Well I set out to build my first robot a while back. I decided on a Kiwi drive.

An example of a holonomic robot would be one that is equipped with three independently driven Mecanum wheels or omni-wheels, mounted in a triangular configuration. This is generally called a Kiwi Drive. A robot that utilizes Kiwi Drive can simultaneously execute controlled motion through both the X and Y axes, and rotational movement.
From: beam-wiki

For a few weeks now I've been cading out a base for this robot. It will have a 6-8inch diameter.

Here are some of the versions of the bases I went through:

v1 base:

v2 base:

v3 base:

v4 base:

v1 top:

So far this is all I can do. These were made in AutoDesk Inventor, this project will ultimately allow me to learn more about Arudino, C#, motors, h-bridges, and many other things. It will be controlled in the end using my android phone, via a bluetooth module. It will stay as an idea until I can get some money (motors are expensive you know).

The motors I'm looking at right now are:

The motor mounts I'm looking at are these:

I'll keep this blog updated with my progress.
If you want some background here is a link to my progress up to now:
ChiefDelphi Forums

Sunday, May 22, 2011

My Robotics Story

I'm a student/Vice President on the J.J Pearce Robotics Team. I currently attend J.J Pearce High School, going into my Junior year. I try to challenge myself, but most of the time my ideas stay just as ideas. Most of my effort through out life was to build something out of ANYTHING.
Since I was very small I've been inspired to do something robotics related. Anytime you saw me during the summer I was looking for something to take apart or build. I never had something to guide me and show me some ways of doing what I wanted to do. Then I found out about my high school after school robotics team. I decided to attend the first meeting for the year despite being skeptical about getting to work hands on any type of robot. To my surprise I quickly become very interested about robotics and very involved in my team. Meeting 3-4 times a week for several hours just to meet a deadline. Building a robot, getting a notebook done, programming, and many other things all in one six weeks. I quickly started to do my own research about robotics in general, I actively started to read HackADay everyday and other sites like it, becoming more and more intrigued.
My fascination about arduino was amplified on a Saturday night at 2am, seeing as I couldn't sleep. I finally became curious enough to find out what an arduino was. I quickly went out and ordered a arduino uno + a kit and started hacking away. My first experiment/project was a blinking set of leds. My addiction grow like an nicotine addiction would, at least I'd imagine LOL. I had a few other projects such as learning how to power a DC motor using a transistor. Finally I settled on a bigger project; The KiwiBot.
A kiwi drive consists of 3 omniwheels all directly driven by motors, mounted in a triangular configuration. The advantage to this design is the movement freedom of the bot. I'm currently still designing it in AutoDesk Inventor. So watch this blog for upcoming updates about this robot.
I'm just mainly interested in robotics. When I get to college/university I'd like to duel major in Electrical Engineering and Computer Science. All this thanks to BEST ROBOTICS, FIRST FRC robotics , and of course to my robotics team the P-51 Mustangs and the volunteer mentors on my team, which receive no benefits for all the hardwork, sleepless nights, and countless man hours they dedicate.. Besides getting the satisfaction of knowing the kids that join have the experience that a normal high school student would never have. I love robotics.

Wednesday, May 11, 2011

Official android open accessory development kit – it’s an Arduino

A new development kit for android was unveiled at the Google I/O 2011 developer conference that officially supports the Arduino.

It looks like Google took a cue from Circuits@Home, because the interesting part of this dev kit is the fact that the shield can be put into USB Host mode. That’s great for phones and tablets that can’t act as a USB host themselves. Google will also release the APIs for this Android/Arduino mashup for 3.1, but it will thankfully be backported to Gingerbread.

We covered the IOIO breakout board for Android last month, but the Google board will be based off of the Arduino Mega 2560, a far more capable device. Interestingly, it appears this board is available now for about $400 USD. We’re not so sure a hobbyist will be buying it at that price.

While this board doesn’t do anything you couldn’t do before with a bluetooth shield, it’s great to see a company supporting all the builders out there.