Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!hplabs!hplabsb!mgsmith From: mgsmith@hplabsb.HP.COM (Michael Smith) Newsgroups: comp.robotics Subject: Re: High Accuracy manipulators (was Re: Robots in our Future?) Message-ID: <5831@hplabsb.HP.COM> Date: 4 Sep 90 16:16:54 GMT References: <1990Aug28.234809.15660@portia.Stanford.EDU> <1990Aug30.014817.8794@portia.Stanford.EDU> <141582@sun.Eng.Sun.COM> <5829@hplabsb.HP.COM> <141710@sun.Eng.Sun.COM> Reply-To: mgsmith@hplabsb.UUCP (Michael Smith) Organization: Hewlett-Packard Labs, Palo Alto, CA Lines: 51 In article <141710@sun.Eng.Sun.COM> barts@cyber.Eng.Sun.COM (Bart Smaalders) writes: > >True to a point, especially with more conventional accuracy requirements- >but the discussion was about manipulators with ~ .0001" accuracy. ... >Most vision-based sensor systems would have considerable >trouble at this resolution level, and would have a very small field of view. A system with an accuracy of ~2.5 microns (0.0001") that uses machine vision currently exists. A small field of view is not very important because the features of parts that require that degree of accuracy are usually also very small. After all, everything is relative. > >In addition, for most assembly tasks the sensor-based system would be >considerably slower, since the robot would need to come to a stop (with time >to damp out all vibration to well below .0001") at least twice before >attaining the final position. > The coordinate measurement machine called the Ultra 1 (from Adept) is actually pretty slow because it is always accurate, even it doesn't need to be. For example, when you pick up a small part from a feeder, you don't usually need to know its location very precisely. The Ultra 1 still has to carry its huge granite links around though which slows things down. >The original poster was interested in moving this sort of technology out of >the lab...that isolated granite table is still probably required, since the >forklifts running down the corridor outside tend to make the robot shake a >thou or two.... And I wonder how stable the camera and lens are over the 20 >degree temp variation we get between the night and day shifts :-). > Assembling parts to ~2.5 microns can be very difficult just as producing chips with fine traces is. You wouldn't produce chips on the factory floor because of course a clean room is required. Similarly, a special environment is usually required for high precision assembly. The robot system should also be mechanically isolated from the floor using commercially available dampeners. >I'm still not sure what product really requires this level of accuracy in >assembly - can anyone clue me in? My guess is that anything that requires ~2.5 microns accuracy is highly proprietary so private companies (such as HP) will be very secretive. Electronic devices in general are shrinking so there should be very many applications in the future. Mike Smith HP Labs