Newsgroups: comp.robotics.research
Path: cantaloupe.srv.cs.cmu.edu!rochester!udel!news.mathworks.com!tank.news.pipex.net!pipex!in2.uu.net!newsflash.concordia.ca!sunqbc.risq.net!hobbit.ireq.hydro.qc.ca!NetNews.IREQ.Hydro.QC.CA!mboyer
From: Jan De Geeter <jdgeeter@gobelijn.mech.kuleuven.ac.be>
Subject: puma762 control
X-Nntp-Posting-Host: amadeus.ireq-robot.hydro.qc.ca
Message-ID: <MBOYER.95Aug11065332@amadeus.ireq-robot.hydro.qc.ca>
Lines: 37
Sender: news@ireq.hydro.qc.ca (Netnews Admin)
Organization: <empty>
Date: Fri, 11 Aug 1995 10:53:32 GMT
Approved: mboyer@ireq-robot.hydro.qc.ca, crr@ireq-robot.hydro.qc.ca

Hello,

In order to get full control of our Unimation Puma 762 robot, we
bypassed the standard VALII controller with our own controller up to
the power amplifier level. We are currently trying to tune a digital
PID controller for each joint.

Unfortunately, up to now we did not succeed in getting stable control
in every position of the robot's workspace (unless we choose the PID
gains extremely low).

We suspect that the high flexibility in the drive train of joint 1 and
2 is causing the trouble. Rough identification of the transfert
function (joint torque/joint position) of joint 1 with the arm fully
extended in horizontal position reveals that there is a antiresonance
at very low frequency (about 7 Hz) and a resonance at about 25
Hz. Joint 2 probably has a similar transfert function.

Has anyone any experience in controlling a Puma 760, or any suggestions?
Thank you in advance.

--------------------------------------------------------
Jan De Geeter

SCK.CEN Belgian research centre for nuclear energy
Boeretang 200
2400 Mol Belgium

Phone: ++32 14 33 26 38
Fax: ++32 14 31 19 93

Email: jdgeeter@sckcen.be

--
 *********************** (moderated) ***************************
     Submissions:                Meta-discussions/information:
 crr@ireq-robot.hydro.qc.ca   crr-request@ireq-robot.hydro.qc.ca
