Subject: Space-tech Digest #57 Contents: Marc Ringuette Robot Workshop Tom Neff Re: Robot Workshop Henry Spencer Re: Robot Workshop Vince Cate Re: Robot Workshop John Roberts Re: Robot Workshop John Roberts Lunar dust Mike Van Pelt Re: Lunar dust Pete Thomas Re: Lunar dust Brian Yamauchi Autonomous Lunar Robots in 1992 Paul Dietz Solar Wind Focusing by Lunar Magcons Brian McCarty Holographic lens? ------------------------------------------------------------ Date: Wed, 21 Mar 1990 01:57-EST From: Marc.Ringuette@DAISY.LEARNING.CS.CMU.EDU To: space-tech@cs.cmu.edu Subject: Robot Workshop I'd like to say more about my visions of a Robot Workshop, and along the way make some comments about the discussion so far. My goal is to extend a virtual human presence into an area the size of, say, a large room: the Robot Workshop. In orbit, this might be a way to do Space Station assembly; on the moon, it could be the means of constructing and maintaining a small mineral processing plant or mass driver. I prefer an octopus configuration, with one central power/communications system, plus ten or twenty small tethered robots. This has major implications for keeping each robot simple: they need be no more complex than robots in a lab on Earth, with power and control connections, motors, cables, and little else. Preferably, they would have some decent force or touch sensors to provide enough information to the operators. I think it is essential that each robot NOT be required to have its own power source, radio link, processing unit, etc. As I envision it, the central system has solar cells or an RTG, communications with Earth including several video channels and teleoperation control channels, and hardware to control which of the robots is being used and which video channels to ship back. I see the robots operating in a 95% to 100% teleoperated mode. My reading on the usefulness and flexibility of AI techniques for operating the robots is that for the various tasks you'd run into in a workshop, a skilled human operator can beat AI almost all the time, even with a several-second round trip delay. The only roles I would look for software to play is are to monitor for problems and do an 'emergency freeze' if an exceptional condition occurs, and to provide local control of simple short-duration operations such as sanding or polishing. I'm pretty solid in this conviction, being an AI guy myself. If you CAN teleoperate, you SHOULD teleoperate. What kind of robots would we need? I imagine anchored robot arms, arms on tracks, arms on wheels, arms with snap-on hand attachments such as wrenches and screwdrivers, cameras on arms, cameras on tracks, fully mobile dune buggies with clips for attaching payloads or cords for hauling, arms with three-finger hands, arms with grippers, arms with hooks, toolkits, glue, duct tape... How do we use these most effectively? I suggest a team of very talented operators, each with separate controls, but working in a common command center where they can yell at each other and help each other out. Not all the robots would be operating at once, particularly if the video bandwidth is a severely limiting factor, which I believe it might. There should be mock-ups of the environment so they can work out problems in the mock-up if they need to before trying it in real life. ============= What does my proposal provide? - A simple, flexible way to project human presence into a workshop. It is relatively low-tech and straightforward. - A heterogeneous and flexible system with minimal hardware requirements. - A system able to do simple assembly and repair. ============= On to some specifics people have mentioned: On temperature control: I bet using heaters really isn't that expensive. Isn't a vacuum bottle what you keep things hot in? Maybe we can get some figures from outer-solar-system probes. I figure all we have to do is make sure that the heat flow is good enough that no part gets left in the cold. Maybe lighting the area with some major floodlights would help. On self-reproducing robots: no way, no time soon, and CERTAINLY not with lunar materials! It would be nice to have robots that could do simple repairs on each other, and standard parts would be nice, but that's about it. Heterogeneity is a big one. I would really like the robots to be able to be developed and operated completely separately, for instance by university projects in several places. Coordination is a BIG hassle, so let's just skip it by making the interface simple - control lines in, video out, and each project can do its own thing. Hedges your bets, too. Gord Deinstadt is definitely right that we should expect things to happen VERY SLOWLY. I think that's OK. There are a lot of hours in a month. On using an External Tank for a garage: ick! An external tank is an unwieldy, fixed-size gadget which would be impossible to manipulate. Use a blanket instead! On migrating south for the winter: definitely not - you only move across terrain if you have to. Not to mention that my proposed system can't move at all. On RTG's versus solar cells: I think solar wins by a lot, in terms of weight, but RTG's provide power 100% of the time. I don't know which wins: if power isn't the dominant weight requirement, it might be worth getting a 100% duty cycle by using RTG's. I don't mean to ignore suggestions for, say, a mobile, independently powered bulldozer. I think it's a fine idea. However, I think a lot of the power of my proposal comes from the fact that a simple system of video cameras and teleoperated arms is very easy and very useful. Amortizing the cost of the rest of the system -- power, communications -- over a number of cameras and arms makes them a lot cheaper. Please tell me what you think! \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ \\\ Marc Ringuette \\\ Carnegie Mellon University, Comp. Sci. Dept. \\\ \\\ mnr@cs.cmu.edu \\\ Pittsburgh, PA 15213. Phone 412-268-3728(w) \\\ \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ ------------------------------ From: Tom Neff Date: Wed, 21 Mar 90 10:03:50 EST X-Mailer: Mail User's Shell (6.5.6 6/30/89) To: space-tech@CS.CMU.EDU Subject: Re: Robot Workshop Two refinements to the Robot Workshop: - You'd want at least two separate power busses and radio circuits available in the workshop (even if both are not constantly in use), so that repairs to a failure in either one can be done using the other, without automatically incurring a human repair call. - Although teleoperation beats AI at Earth-Moon distances for many things, I think it would make a lot of sense to give the robots enough sense to obey "GRASP X", "PUT A ON B", "UNSCREW" and so forth. The feedback loop would tend to interfere with smooth operation otherwise. And it is something we can do, unlike "FIGURE OUT WHAT IS WRONG AND FIX IT AND REPORT BACK" as some of our more eager beavers would go for. - How about five arms and three eyes per station. The teleoperator picks an eye-pair for stereo vision, but can switch pairs at will for a change in perspective without having to move or wait (also an assistant can monitor his work from the side). The five (or whatever) arms include a "bottom arm" with a support platform attached to hold small work, two general purpose manipulator arms and two hold/transport arms. -------------- This concept could work in orbit or on a planetary/satellite surface. In all cases you need a reliable automated way of getting new stuff TO the workshop. In orbit the Progress system works. On the Moon you have other problems. An automated soft landing + breakdown technique, combined with a teleoperated 'drag rover' might work. But this won't be simple to achieve. --Tom Neff ------------------------------ From: henry@zoo.toronto.edu Date: Wed, 21 Mar 90 12:36:22 EST To: space-tech@CS.CMU.EDU Subject: Re: Robot Workshop > On temperature control: I bet using heaters really isn't that expensive. > Isn't a vacuum bottle what you keep things hot in? Maybe we can get some > figures from outer-solar-system probes. I figure all we have to do is make > sure that the heat flow is good enough that no part gets left in the cold. > Maybe lighting the area with some major floodlights would help. The heaters themselves are easy; the problem is *powering* them during the lunar night. (Remember that you have to keep your batteries warm too...) The outer-planets probes are swaddled in insulation and still have heaters running constantly in major subsystems. When JPL finally and firmly decides that Voyager's cameras have taken their last picture, the camera heaters get turned off, and the cameras are then considered defunct. Batteries are very heavy for the amount of power they store, and have limited lifetimes. It would be better to avoid relying on them at all. (One reason the Voyagers have lasted so long is a complete absence of batteries.) Running heaters off batteries is very expensive in mass and battery lifetime. Barring the possibility of building a heat-storage system, I really think the simplest approach is to have everything huddled in an insulated, RTG-heated garage, powered down to bare minimum, during the lunar night. With solar during the day, and the RTGs keeping things warm and supplying housekeeping power during the night, with luck you won't need a battery system at all. Henry Spencer at U of Toronto Zoology uunet!attcan!utzoo!henry henry@zoo.toronto.edu [[ Use little RTG pellets for heating! --Marc ]] ------------------------------ Date: Wed, 21 Mar 1990 11:21-EST From: Vincent.Cate@SAM.CS.CMU.EDU To: space-tech@CS.CMU.EDU Subject: Re: Robot Workshop If all the robots need to stay in one room because they are on short cords you greatly limit what they can do. If they are just doing some assembly work there is a good chance that standard assembly line robots could be programmed to do it. I agree there will be need for the remote presence stuff and I like it alot (especially for doing things in LEO). Having the robots share a communications link to Earth and access to on the moon data and computing power makes sense. Having a central power system makes sense as well. However this does require putting a leash on the robot (power cord). Batteries work well enough and there is no FCC so you have plenty of radio bandwidth for communication with the base. I am surprised people are more inclined to lock robots up 14 out of every 28 days than have them migrate south. At 100 to 150 miles per day the robot caravan would need to average 4 to 6 MPH. I don't know if I have ever seen an ATV go this slow. :-) Really though, that should not be a problem even for electric ATVs. Remember that at 1/6G it is easier to go up hills. The front car could be extra large and even smooth out and pack down a dirt road. Another thing I think will need to be done on the moon is to lay a power line that goes a little more than half way around the moon. If you put solar collectors at both ends you can make a power system that have power all the time. This 3000 mile cord would have to be made on the moon. Insulating it well enough that you could send a high voltage through it while it is laying on the ground could be hard. Anyway, this cord seems like the kind of thing we could make make on the moon and it would be very useful but will probably not be done in the first few years on the moon. -- Vince [[ I think moving across the moon is still a totally nutty idea. It's way too hard for the benefit you get! --Marc ]] ------------------------------ Date: Thu, 22 Mar 90 14:10:07 EST From: John Roberts Disclaimer: Opinions expressed are those of the sender and do not reflect NIST policy or agreement. To: space-tech@CS.CMU.EDU Subject: Re: Robot workshop [ with respect to the discussion on staying warm...] A question which I think is relevant: How deep is the point at which the temperature is pretty much constant throughout the lunar month? What is the temperature there? If nobody knows, are there any educated guesses? (Since it presumably makes a difference, say these questions apply to conditions at the lunar equator, away from crater rims.) John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: Fri, 23 Mar 90 19:42:20 EST From: John Roberts Disclaimer: Opinions expressed are those of the sender and do not reflect NIST policy or agreement. To: space-tech@CS.CMU.EDU Subject: Lunar dust From: Gord Deinstadt >Both solar cells and RTGs have a serious problem when used >on the Moon; dust! Every moving vehicle is going to stir up >dust, and that is going to coat any nearby solar cells or RTG radiators... Keep in mind, however, that dust won't behave the same way that it does on earth. Every activity that involves contact with the soil will kick up dust, but the dust particles won't stay suspended and drift. Instead, each particle will move in a parabolic trajectory, and most of them will end up fairly close to where they started. Possible exception: if the dust becomes electrically charged, it will stay suspended for a while, and it may be attracted to equipment. Has anyone investigated this possibility? John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ To: space-tech@ames!cs.cmu.edu From: Mike Van Pelt Subject: Re: Lunar dust Date: 24 Mar 90 01:34:36 GMT Hal Clement wrote a short story called "Dust Rag", in which a couple of lunar explorers are just about done in by dust clinging to their facemasks and obscuring their vision. Mike Van Pelt |"Dreams of flight are universal among space-faring races. Headland Technology | Indeed, such dreams may form much of the motivation for (was: Video 7) | becoming space-faring." -- T'chaih Hrinach ...ames!vsi1!v7fs1!mvp ------------------------------ Date: Fri, 23 Mar 90 21:57:35 -0500 From: "THOMAS, PETE (TEACHING ASSISTANT" MMDF-Warning: Parse error in original version of preceding line at CS.CMU.EDU To: roberts@CMR.ncsl.NIST.GOV, space-tech@CS.CMU.EDU Subject: Re: Lunar dust > Keep in mind, however, that dust won't behave the same way that it does on > earth. Every activity that involves contact with the soil will kick up Precisely this problem has been seen in the past. Spacesuits and equipment would get coated with dust because of electrical attraction. I think the solution was basically "wiping off the dust." However, in any fairly automated system this may be difficult. Could a grounding device, or even a precipitator, be made to resolve the problem? (I can picture a rover bouncing along, kicking up dust--and the dust being drawn towards charged "bumpers" along sides or back. Maybe a useless or partial solution--any ideas? --Pete ------------------------------ To: space-tech@CS.CMU.EDU Cc: yamauchi@cs.rochester.edu Subject: Autonomous Lunar Robots in 1992 Date: Sat, 24 Mar 90 22:05:04 -0500 From: yamauchi@cs.rochester.edu At the Artificial Life II Conference, Rod Brooks (of the MIT AI Lab) gave a talk where he mentioned that his lab was currently developing robots based on Ghengis (a six-legged, 1kg, fully autonomous, behavior-based walker) which he hoped to launch to the moon in the next two years. He said the entire mission would cost about $10 million, and that he was planning to launch these bots on a private launch vehicle. He also mentioned that he was pursuing "unusual" sources of funding. I talked to him afterwards, and he said that these robots would be solar powered (something like half an hour of activity for every four and a half hours of charging) and would include various tactile and force sensors, as well as some low-level visual behaviors. Another interesting tidbit from Brooks' talk at the ALife 2 Conference was that his project to build gnat robots was recently funded, and that he expected to have a 1 cubic millimeter (yes, millimeter) microbot prototype working within 3 years. _______________________________________________________________________________ Brian Yamauchi University of Rochester yamauchi@cs.rochester.edu Computer Science Department _______________________________________________________________________________ ------------------------------ To: space-tech@CS.CMU.EDU Subject: Solar Wind Focusing by Lunar Magcons Date: Mon, 26 Mar 90 12:49:45 -0500 From: dietz@cs.rochester.edu I just read an interesting paper in the 19th Lunar and Planetary Science conference proceedings. The idea was that some interesting "swirl" features on the lunar surface are due to local shielding of the surface from solar wind weathering by local magnetic anomalies ("magcons"). Simulations showed that local surface fields of 1000 nT would produce local shielding. Of interest for lunar mining is that the magcons would also create regions where the integrated flux of particles is increased. This could, I imagine, lead to larger amounts of such useful materials as hydrogen and helium-3 in local deposits. If the different charge/mass ratios of protons vs. helium-3 ions leads to regions where the former are excluded but the latter are not, which might lead to larger amounts of trapped helium. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: Wed, 28 Mar 90 09:33 CST From: "Brian P. McCarty (N9IWP)" Subject: weird idea To: space-tech%cs.cmu.edu@vma.CC.CMU.EDU X-Organization: University of Wisconsin--Platteville I just came up with an interesting idea (I doubt it's original, but who knows). I attended a holography presentation yesterday and the presenter made a quick comment about a holograph of a lens is a lens. What I am wondering is is it possible to enlarge a holgram? Could one make a holgram of a lens, enlarge it, and then have a huge telescope lens? seems to me the main problem with big lenses is the thickeness needed. But a hologram could be put on a mylar sheet. There's probably a zillion practical reasons why this might not work, but right now I'm in the "it's neat enough that it doesn't need to work" stage. Brian P. McCarty, N9IWP bitnet:UCSBPM@UWPLATT internet:UCSBPM@UWPLATT.EDU ^-- located in the same state as the largest refracting telescope in the world ------------------------------ End of Space-tech Digest #57 *******************