A Well-Balanced Robot

March 10, 2008

As far as walking goes–emotions are another matter.

From the Anybots website, with my emphasis added:

Dexter is quite different from other robots that have walked on two legs. The Honda ASIMO and related robots use a walking algorithm called Zero Moment Point or ZMP, a geometrical constraint that guarantees stability. To use this approach, a robot must have stiff joints (driven by geared servo motors) and fairly large feet. In the simplest version, the robot is given pre-planned movements that guarantee that a perpendicular drawn from the center of whichever foot is on the floor passes through the center of gravity, with some compensation when it accelerates. Such a robot does not need active balance feedback to walk. While the most advanced ZMP-based robots do include active balance control to adapt to sloped floor surfaces or external forces, this is a refinement to a passively stable gait.

Dexter has a different, more human-like body on which ZMP control does not work. Its joints, driven by air cylinders, are springy and flexible like human muscle. There are no stable postures that it can be put in where it can balance without active feedback, so it has to constantly adjust based on its sense of balance, the robot equivalent to your inner ear. It walks and balances the same way humans do, even wearing the same shoes humans wear.

Dexter’s harder-to-control body has major advantages in the real world. It can walk just as easily on soft surfaces, like the deep carpet shown in the video, as on hard surfaces. Because its joints are flexible and able to absorb impact, it will be able to run at high speed over uneven ground and jump over obstacles. If it accidently steps on your toe, it won’t hurt any more than a person stepping on your toe. But most importantly, because there is no geometrical principle by which we could have programmed a walking motion, it had to learn to walk. Its learning software will soon lead to a much wider range of walking abilities than could ever have been programmed.

And Ray Kurzweil shudders in fear…


The Epitomal Transhumanist

January 19, 2007

This video of Ray Kurzweil (about 23 minutes long) is an excerpt from an annual seminar called TED Talks (for Technology, Entertainment and Design) that features leaders from a variety of fields. While most of the talks seem to focus on society or technology, the perspectives are quite broad: Al Gore, Rick Warren, Daniel Dennett, Bono, and Richard Dawkins have all graced its stage in recent years.

Ray Kurzweil is a prominent transhumanist, and has one of the most optimistic views of technology possible. One of his more recent books is The Singularity is Near, which describes his view that not only is the eventual surpassing of humanity by artificial intelligence inevitable, it is also nearer than we think. In Kurzweil’s view this process will include the merging of our own personal consciousness with the advanced capabilities of computers to eventually be able to process more quickly, analyze more astutely, retrieve data more accurately, and so on. In Kurzweil’s view, what truly distinguishes homo sapiens is not our current biological status, history, or accomplishments, but our impetus to transcend our limitations. Technology merely offers us a new vehicle for our transcendence.

Regardless of whether you embrace his views wholeheartedly (they seem a bit optimistic even for me) or you feel a shiver of terror or silent mockery slipping down your Luddite spine, Kurzweil’s thought should be examined because of his influence. He’s a successful inventor and author, and a prominent figure among futurists and transhumanists. Here’s a summary of sorts of Kurzweil’s TED talk:

Can we predict the future? While certain specifics of technological progress are very hard to predict, overall trends are predictable, and they’re also exponential. Growth in one technology enables and promotes growth in another technology. 50 years to adopt telephones, 8 years to adopt cell phones. TV took decades, but new technologies- like the internet- have taken off much faster.

Kurzweil then makes an analogy to biological evolution. The evolution of genetic material (DNA/RNA) took billions of years, but once certain genes were in place (or the common “tool-kit,” as evo-devo would put it) more rapid (~10 million years) change, like the Cambrian “explosion” (a term that is disliked in many circles) can occur. But as the first technology-creating species, our culture has allowed us to “evolve” on a level that is exponential in comparison to biological evolution (which is one reason we have a hard time understanding evolutionary time scales).

It took tens of thousands of years to develop agriculture, then thousands to move to more centralized forms of government (those two are arguably related, but the direction of causality is disputed), civilization led to quicker technological development, etc. The last 500 years of technological growth were incredible, but the last century has been even more impressive- bringing us widely available automobiles, radios, TVs, airplanes, medical technology, computers, Internet, not to mention space flight and an incredible plethora of new weapons systems with which to butcher each other.

This emphasis on technological development as an exponential process is a major theme of Kurzweil’s work. But, he points out, people always begin doubting when exponential growth for future technology is predicted. This growth is a result of

“worldwide chaotic behavior.. You would think it would be a very erratic process, yet you have a very smooth outcome… Just as we can’t predict what one molecule in a gas will do- it’s hopeless to predict a single molecule- yet we can predict the properties of the whole gas using thermodynamics very accurately. It’s the same thing here- we can’t predict any particular product, but the result of this whole worldwide chaotic, unpredictable activity of competition in the evolutionary process of technology is very predictable, and we can predict these trends very far into the future.”

Kurzweil also talks about the suboptimal nature of much human biology (so much for perfect design). For example, our metabolism, which leads us to hold onto every calorie, is a throwback to our hunter-gatherer days and is something that we might like to modify to prevent obesity in developed nations. And another problem, which seems to be Kurzweil’s main fascination: “Long life spans (as in more than 30) weren’t selected for.”

While some of his examples are sketchier than others, the idea of an engineered erythrocyte (red blood cell) that could increase oxygen capacity greatly is particular interesting. In my view, Kurzweil has a tendency to exaggerate about some possibilities, but then again, exponential growth will always appear as an exaggeration to those in a linear-growth mindset.

I think more important than any individual predictions about technological progress that Kurzweil makes (like reverse-engineering the brain by 2020), his main point stands: the progress of technology throughout history has been accelerating. The main question tends to be whether we’ll be able to harness these technologies to make life more certain, more pleasurable, more equitable, more eco-friendly, and more connected (and therefore more meaningful on some level) or to just wipe each other off the planet.