robot page one:
Project: EL BO Menu & Concept Page

Project: EL BO
Newest update: 8/14/99

   Elma Beaucoups (8/14/99)
   engineering solutions (7/28/99
   current photos (7/11/99)
   elbow technical (7/5/99)
   shoulder technical (7/5/99)
   brains technical (7/5/99)

Project History

    This is an early artist's concept of the EL BO 1000.
   As you can see, the robot recruits human assistance to exhibit phototropic (light seeking) behavior.
    EL BO is short for Elma Beaucoups. The 1000 stands for nothing. It just sounds cool.

   After research indicated that the above robot would be economically unfeasable, we arrived at this new improved artist's concept. In this form, the robot is basically an arm which is independently phototaxic (aligns with light.)
    At this point we amended the name by subtracting the "1000" because anything which would call itself "olivia" could never be a "1000" This is not to say that Olivia is a bad name...maybe Molly 1000... Heck, Molly... Molly could probably make "5000"... but Olivia 1000...
    However, this design lacked appeal...

Elma Beaucoups

The Name:
    Elma Beaucoups is a flower at heart, and a machine in body. The name came after I spent 2 months calling Elma "the elbow" which turned to "EL BO" and later, after being jokingly prodded by most of my friends about how it was my new girlfriend (and was going to keep me warm at night,) the name changed a lot. A few examples: "Eliza Bonita," "Ellie Bowler." The name that stuck was finally "Elma Beaucoups," which translates from French to "Lots and lots of Elma."
   Oui! Oui! Oui!

The Parallax Basic Stamp Microcontroller

Current Specs & Info:
    Elma Beaucoups was designed to be an autonomous phototaxic robot arm. For portability, I wanted all necessary electonics to be mounted on the arm (instead of tethering the thing to a PC.) Since it was my first robot I guess I had to do everything the hard way.
    Elma was built from scratch. A lot of people talk about not wanting to redesign the wheel, and while I can see the rationale, I wanted to really learn the nuts and bolts of robotics. Looking back on it, life would have been a lot easier using servos, and sometimes I regret not using them. At the same time, though, shaft encoders are really neato.
    Elma's brain is a Basic Stamp 2 (BS2.) Elma is also equipped with a dual H-Bridge to drive the motors, and an IR remote system which operates using Dial Tone Multi-Frequency tones to transfer information. Elma talks to the world via beeps through a simple amplifier circuit & speaker. To increase the number of I/O pins available, Elma is equipped with a parallel-in serial-out 8 bit shift register.
    The flower is a piece of origami. Without it Elma looks kind of strange.

Building a hobby robot without model airplane servos.

    One gear head DC motor drives the shoulder via a drive chain system, which provides further reduction. The elbow is driven with a DC motor using a worm gear drive train scavenged from a defunct VCR.
    Elma Beaucoups can operate autonomously using photoresistors to display phototaxic behaviors. The robot has only two degrees of freedom. An optical shaft encoder is used to determine shoulder position and a bend sensor provides elbow position. Since both encoders are absolute, no limiting switches have been installed.
    The IR remote can be used to tell Elma to rotate to a certain angle and bend the elbow to a certain angle. It is also possible to drive the elbow & shoulder continuously via remote control.
    Elma is tethered to a 9 volt AC to DC converter. Some of the electronics and the motors run at 9 volts. Everything else runs at 5 volts, which is supplied by the BS2.

Major Problems Encountered:
    Connections seem to be the woe of all roboticists, and my experience was no different. After suffering bug after bug after bug, I finally had to resort to crimping and carefully soldering all my wire-to-connector joints.
    As of this writing, my other biggest problem is sensor oversensitivity combined with motor overshoot, which has forced me to use rather low resolution on the encoders and strange oversampling and overcompensation routines in my software. I'm still working on using PWM & velocity control to slow Elma down gracefully when approaching the end of a movement.

Building a hobby robot with surplus electronics parts

    Time to build: So far around 3 months, working whenever I get a chance.
    Cost: Not counting man-hours, probably around $300 for everything currently installed. Tool purchases and R&D costs are probably significantly higher than that.
    Other important information: If you have ever dreamed of creating a robot I would very stongly encourage you to start today. It is a great learning experience, and a lot of fun. While it is really cool and challenging to build something you can direct via remote control, it is another thing altogether to see something you built make decisions and move on its own. Even though I had a vision of what it would be like, when Elma finally became autonomous it really freaked me out somehow.
    It's like being Dr. Frankenstein. Oh! And your friends will enjoy playing with it.
    Future Directions: Besides tiny system upgrades and improvements, I am considering motion detection and other sensor arrays for Elma Beaucoups. I also have ideas for two other robots now.

Older News & Photos

    I started this project about three or four months ago.

   Because a lot of people have expressed curiosity, I decided to put up these pages despite the fact that it is unfinished. These pages are especially for a certain pal o' mine in Chicago.
    It had been well over a decade since I had done any programming in Basic, and even longer since I had taken electronics in High School. Even worse, building a robot from scratch means learning about "cleaning up" power supplies (yawn,) motors (better,) properly crimping connections, electronic communication, levers, and gears & stuff you wouldn't think even existed.
    Honestly, I didn't expect it to be such a difficult thing to do. I have done so much research on the subject that I have accumulated a three foot pile of manuals, books, printed web pages, information about different plastics (delrin is king) and chip data sheets.
    These here are my absolute favorite web sites on robots. For inspiration, my fav is MIT. They have been building both a robot fish which actually swims like a fish and a tiny robot dinosaur. Both these sites have cool movies you can download to see the robots in action. For homebrew technology, the Seattle Robotics Society has the hands down best how-to information anywhere. Recently (2009) I decided to start my own blog on robot vacuum cleaners like the iRobot Roomba.

    In the meantime, I have burned out an LED or two, a bunch of transistors, an IR sensor package, a couple chips, and have gone through quite a few inadequate motors. The design is being carried out modularly, building sections, doing programming, and making sure they work to spec (i.e. reliably and with more than enough power) while assembling.
    The truly distubing thing is reading web pages by people who, in a couple weeks, have created robots that can climb up your curtains, respond to spoken commands, and avoid rubber balls thrown by their little sisters while simultaneously tracking and shooting down house flies with a CO2 laser, all with tinker toys, a 9 volt battery and Radio Shack DC motors.
    Although it isn't anywhere near as sophisticated, EL BO is packed with lots of bells and whistles, and will be easily programmable for other light-based behaviors. Due to its modular design, it will also be easily upgraded with other motors, sensors, and power sources. Below are links to different sections (with photos) of the robot design as it stands now. I have tried to keep most of the explainations simple, while at the same time, throwing in a bit of jargon and technicaleze for other roboticists, programmers, and technophiles.



All this stuff copyright, 1999 Dave Benz

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