Efficient Actuator?

Mark Tilden, of BEAM robotics fame, has created a new robotic toy (http://www.wowwee.com/catalog/other_robosapien.html ) with a surprising
amount of capabilitiy. The videos (http://www.solarbotics.net/gallery/Wowwee-Robosapien?page=2 ) of Tilden demoing his creation are pretty amazing. Aside from the clever body structure that allows dynamic movement without the aide of gyros or complex computations, the actuators are comprised of a motor and gearbox that is 50% efficient and allows the bot to run off of a few AA batteries for 20 hours.
This efficient yet dynamic actuator is what caught my interest. Does anyone know how you could get an actuator like this and how strong it would be?
Chris S.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I thought I understood him to mean that the inverse kinematics of the body (ie. when one arm extends, the body rotates along the torso because of the shift in weight) would cause the non-used, but rotated motors to generate electricity (notice in the videos how much the robot weaves its torso.) This energy would then be stored to use along with the batteries, thus increasing battery life. At first thought, it wouldn't seem that you could generate enough electricity from those little semi-rotations, but with a proper gearbox, that little rotation could be transformed into many rotations at high rpms. I believe this concept is the same as regenerative-braking or coasting in an electric car. Perhaps the torso piece is not a motor and actually a generator designed to have high-output under those conditions.
Without doing any math or detailed analysis, the above statement seems possible. Whether or not this is what was done, or just my interpretation remains to be seen. I for one, have pre-ordered this robot and will have to find out in August (damn the wait!!)
BTW, did it look like to you that the arms had the full range of movements in the joints? I hope so, that is what is drawing me to it the most. Hopefully, it will have hacking possibilities, as programming it with the remote would wear itself out in the fun department rather quickly. I believe it is using IR, though, and a simple decode of the commands and some programming of an IRDA-capable PDA (or gameboy color) might allow more intuitive programming.
Scott

complex
50%
hours.
anyone
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Not sure. Although the little guy looks pretty cool, remember that it is just $100 so some limitations are to be expected. From the videos I'd say each limb is attached to a rotatry actuator set at 45 degrees to give the illusion of broader movement. Overall, it looks like each arm has only 2 dof, 3 including the grippers. Even so, I agree that this is definitely hackable.

believe
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.