Saturday, February 28, 2009

Last few Weekends in Korea - Pool Hall

This weekend I decided to go out on Friday with one of my good friends from Uzbekistan. We went to a local pool hall to shoot around. I had a good night I won 4 of the 6 games we played. Here is an action shot from last night!

The Dynamixel

To build a mini robot you need to have small motors to drive the articulation of each joint. In Hubo's case It uses a complex set of multiple motors and drive belts in combination with Harmonic Drive systems to produce movements and have holding torque to stand and move. This method work wonders for Hubo but is not a good system for a small system for reasons that it is bulky and very expensive. On top of the mechanical complexity it needs to have custom motor controllers to drive the motor train as well. Small Humanoids can use a off the self package that includes a motor, gear set, encoder, and controller. These servos are far more cost effective, light weight, and have far less overhead to program the included controller. The servo package we chose for this project is the Robotis Dynamixel. Robotis is actually a Korean based Company that sells robot kits such as the Bioliod Humanoid. They sell many other accessories and servos for people interested in building custom Humanoids like ourselves. We deiced to go with the RX-28 that supplies 28N.m of torque for leg servos and RX-10 (10N.m) for the upper body.

Robot Inspiration

I spent many hours searching internet based videos to see what types of designs existed for small Humanoids. Granted I know the design of Hubo inside and out but yet this robot could not be as complex. So I needed to "switch gears" to start thinking in the perspective of small robots. I found two robots that I liked that were featured in the ROBO- ONE, a Japanese competition. The first robot that gained my interest was the Kondo KHR-2HV.
I liked the legs where the knee joint is set on an angle to the perpendicular part of lower leg and foot. This allowed the robot to have a very fluid motion during walking. I also felt it did not have to Throw its leading and trailing leg as far to achieve locomotion.

The second design that also took my interest was a small robot also from ROBO - ONE. This robot is called OmniZero.
The video shows the unique construction of the robot, notice that this robot has two motors at the knee joint. The double knee is much different than most Humanoid robots competing. Most robot have a single motor actuating at the knee, but in using two motors in the knee allows each motor to rotate half the distance. This allows of for faster actuation at the knee and I believe that this is a potential design for a more capable running robot.

RoboGames - Introduction

Robogames is a organization that hosts many robotics competitions such as Soccer, Combat and Humanoid. Each year an event is held in San Fransisco where many robots from all over the world come to compete. This year in June DASL will be making their daybiew into the Mini Humanoid competition. Dr. Paul Oh has formed a team consisting of four of his undergraduate and Two graduate researchers. This powerhouse team has been challenged to design, build, and program a bipedal walking robot in less than 6 months. I was brought on board for my mechanical skill set with CAD and Manufacturing. I have challenged myself to come up with a unique and fresh design to be featured in this robot. The past month I have been busy pushing many CAD designs and just lately have seen the fruits of my labor. In the next few post I would like to share my designs and my process I took to reach my Final Product. The following is the schedule that I have been following to keep myself of track for the last few weeks of my Co-op in South Korea.

Feb. 9th - 11th Finalize Robogames CAD of Legs/ Feet
Feb. 12th - 14th Produce CAM with MasterCam of the Legs/Feet
Feb. 16th - 17th CNC parts at Hubo lab
Feb. 17th - 21st Torso/ Arms Finalize CAD
Feb. 21st - 28th Produce CAM for Torso/ Arms
Mar. 1st - 7th (Overflow) CNC of Torso/Arms
Mar. 1st - 7th Start MasterCam Documentation for tutorials completion April 1st.
Mar. 7th - 13th Rap up loose ends with Hubo 2 CAD and Documentation

Friday, February 13, 2009

Trip to Beijing China

During my first few months living in South Korea I had an opportunity to collaborate with the design and manufacturing company that created the Shells that encase Hubo. The owner of the company ( is expanding his business to China in the next few months and is going to establish offices in the Japan and the US in the next two years. He asked me to join him for a business trip to lay the ground work for the company in Beijing. The 4 days we stayed I joined him in business meetings, site seeing, and evening activities. I visited Beijing Industrial Design Center and I met the Director of the company. He invited us to dinner at the very famous restaurant Quanjude where the main dish is severing Duck. So a little background history on this place it was established in 1864 during the Tongzhi, Qing Dynasty. Apparently Ronald Reagan ate there when he visited China too! So since the the opening they have kept a tally on how many ducks they have served to the public and I my stomach became the proud owner of number 435055! I said that I ate duck... I ate basically the whole duck. The list you would like to know? Heart, Liver, Feet, Brain, Skin, and regular old body meat! Did I like it? Heart was actually pretty good, but Brain...too mushy , odd tasting at best! Above is the picture of the Head of the duck,I had to search for the Brain...It was very samll! But every thing went down smoothly with some Chinese alcohol... 52 % by volume... WOW! During the my remaining stay I ate many tasty cuisines and also saw many location around the City. I visited the place where the 2008 Beijing Olympics was held and I also visited the CCTV building. Both of which I only dreamed of seeing after I saw the Discovery Channel special! I also visited Tineman Square and browsed many small trinket shops. In the evenings we went out and enjoyed the social life visiting many bars. The first night we visited a North Korean Style Bar. Now this was a very interesting experience... I was told that I was the First American to ever come to this bar.... and it was weird for the waitresses at first because I could speak a little Korean. Very Hospitable people, I saw a traditional North Korean dance and drank North Korean Style alcohol. I actually had a really great time there! I also got to visit a very famous Club called Cargo. There I met one of the Directors that produced a part of the Beijing Opening Ceremonies, a TV producer, and a Chinese actress. I was a crowd favorite on the dance floor, even thou I could not speak any Chinese... We expressed are self through dance! Through my meeting with one of the Directors he gave our party free entry into a traditional Chinese theater! Overall I am glad I went to China, I would like to return and visit more places like The great wall and other Cities!