Monday, December 16, 2013
To my friends in the PRT community… I want to explain my sudden disappearance and long absence. Some of you may have experienced challenge of caring for an aging relative. Well, I have three such relatives, and they have all been living together in a big old house, unable to agree on when or where to move to get the kind of assistance they increasingly need. The youngest, (83) is particularly stubborn and has basically told me to “Butt out” for years. Obviously this standoff could only end badly, and now everything has really broken down. We are have been dealing with senility, anxiety disorder, financial difficulties, mobility and a host of other problems for a while now. Now the mainstay of the group has required 2 emergency surgeries in the last 5 weeks. It is stage 2 cancer. As the only "available" family member this has put me in a tough position. It is especially difficult, I have found, to clear my head enough to write this blog. Frankly, every time I start writing, I simply fall asleep. Such is my physical and emotional exhaustion. Also there are, after all, over a 150 posts already, so most of the more important topics have been discussed and re-discussed, and the main mission of this blog has been largely achieved. The kind of incremental design improvements that remain will hardly make gripping reading material, so its not a great time to have writer’s block. Moreover, any efforts toward this site would seem to be best spent organizing the existing material into a more cogent presentation. As it stands now, most of the best material is already deeply buried, and I am not inclined to add fluff just for the sake of posting new reading.
But believe it or not, there is a silver lining. When I am under a lot of stress I have always found relief by tinkering in the shop. Lately, in the evenings, I have found myself pushing forward on the scale model of the “SMART” PRT system. (Suspended Multi-axis Automated Rail Transport) Such pursuits are easy for me to organize into sub-projects that can be worked into my bits of free time. It’s like knitting. The project may be big, but it’s relaxing and easy to pick up and put down. In this way I have actually made a fair amount of progress, and this seems like a better use of my time right now.
I have come to believe that society really isn’t ready for PRT. It is too big of a change and too counter-intuitive to be championed by anyone in the public sector. Yet I believe it will happen eventually, since leaps in efficiency are inevitable over time. Revolutions come when evolution is stymied. I believe that the case for PRT will be made obvious (and therefore less risky) by related technologies becoming more commonplace. Delivering people around a city is not that different from delivering packages around a distribution or mail center, delivering meals in a hospital, baggage in an airport or pallets around a warehouse. Robotic technologies will increasingly replace current systems and evolve, I believe, toward overhead rail-based systems. “Pick and Place” is already one of the most common uses of robots, and it seems inevitable that their gantries will only get longer and robots will need to be untethered. It also seems inevitable that work will increasingly be done cooperatively by multiple robots on these overhead rails. A system using many untethered robots, moving materials around larger and larger arenas, basically demonstrates and proves the PRT concept. Jeff Bezos, in unveiling plans for home deliveries via drone helicopters, is surely conscious that his (3D) solution also applies to a similar problem existing within Amazon’s own distribution centers. Miles of conveyor belts are a slow, awkward and inflexible (basically 2D, gravity-based, inertia limited) architecture that is roughly analogous to the roads he seeks to circumvent. A small army of pick and place robots running around a 3D rail network could reposition items many, many times faster - without the insane hive noise and energy consumption of the drones.
Since this is my take on the PRT situation, I think the next step is for me to demonstrate just how simple the mechanics of such a system really are. Unfortunately I no longer have a machine shop at my disposal, but even this is sort of a blessing. After all, if I can build these things with simple hand tools, it’s a pretty strong indicator that mass production won’t be problematic. One disclaimer though; Making this model to scale is not at all easy. My homemade circuit boards, for example, would scale up to be suitcase sized, but I need to fit them in somewhere, nevertheless. There is a necessary learning curve where parts are built just to act as place holders and to experiment with the fabrication methodology. Then they are tossed and replaced by something better and easier to make. So let’s just say patience is a virtue!
Posted by Dan at 10:43 PM