I have the exact robot. I have been having problems finding the specs on the servos - so thank you very much. - the small ones then are 2A and the large ones are 4A. cool. I read references to the encoders being sin/cos output. I figured I would believe it when I got around to hooking them up. seems a bit odd. If all else fails - encoders are cheap. We did not get any of the control electronics.
my arm has black electrical tape on each joint for alignment. :) http://www.electronicsam.com/images/puma/pumaarm.jpg sam ----- Original Message ----- From: "Jon Elson" <[EMAIL PROTECTED]> To: "Enhanced Machine Controller (EMC)" <[email protected]> Sent: Sunday, August 24, 2008 11:50 PM Subject: Re: [Emc-users] Puma560 > Jonathan Hancock wrote: >> Hi Jon. Thanks for your response. I hope this helps: >> >> >> >> The Puma560 has 6 joints all having 40v dc brushed motors. The 3 lower >> joints are rated at 160W and the final 3 at 80W. >> >> >> >> The encoders are sin/cos types with differential outputs and an index >> output. I can convert this to A/B square waves if necessary. > You'd better check the resolution of these encoders. Some (not > all) analog output encoders have low resolution and use > interpolator boxes to develop the needed resolution. These > Rho-Theta style arms need to have pretty high resolution in the > joints or there are certain positions it can get into where tiny > movements of one joint can cause big errors in end effector > position. > Each motor >> also has a pot on the back for the control system to find its home >> position at power-up. There are no limit switches. >> > Hmmm, no limit switches, huh? Well, there is no standard > arrangement in EMC2 to use pots for setting joint limits. You > could, of course, build some electronics with pairs of > comparators to detect a joint at the travel limits. You would > at least need some kind of sensor to set a home position for > each joint. >> >> >> The tree lower joints have a break that needs to be energised by 24v to >> allow movement of the motors. >> >> >> >> I'm not sure what the control signal to the existing amplifiers needs to >> be as I have very little documentation on my system. I am happy to >> replace them for a more modern solution if it's easier. There is however >> a 'high power discharge' board in the original to soak up the high >> voltages created by the inertia of the arm. I guess I can use the >> original psu to provide +/- 40V. >> > It could be +/- 10 V analog velocity commands, or torque > commands. But, unless they are a standard brand (Servo > Dynamics, Westamp, Kolmorgen or such) it might be hard to get > docs on them. If you have tachometers on the motors, then it is > likely to be a velocity servo, and you may want to preserve the > servo amps if they are still functional. If no tachs, then I > wouldn't worry too much about saving them. >> >> >> It would be great to get this working properly as it's been a long term >> ambition. I've found some university sites that have made changes to the >> original controller but none that have started again. And then there's >> the software....! > But, EMC2 makes it fairly easy. You have to determine the > destance between joints precisely and set up the reverse > kinematics for those measurements, and EMC handles it pretty > much from there. You do have to work out the correct homing > sequence so that things don't collide during that movement. > > Jon > > ------------------------------------------------------------------------- > This SF.Net email is sponsored by the Moblin Your Move Developer's > challenge > Build the coolest Linux based applications with Moblin SDK & win great > prizes > Grand prize is a trip for two to an Open Source event anywhere in the > world > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > > No virus found in this incoming message. > Checked by AVG - http://www.avg.com > Version: 8.0.138 / Virus Database: 270.6.7/1631 - Release Date: 8/24/2008 > 12:15 PM > > > ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
