Path: csiph.com!feeder.erje.net!2.us.feeder.erje.net!feeder.usenetexpress.com!feeder1.iad1.usenetexpress.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!buffer1.nntp.dca1.giganews.com!nntp.supernews.com!news.supernews.com.POSTED!not-for-mail NNTP-Posting-Date: Fri, 12 May 2017 10:17:05 -0500 From: Randy Yates Newsgroups: comp.dsp Subject: Stability in PID Controllers Organization: Garner Underground, Inc. Date: Fri, 12 May 2017 11:17:05 -0400 Message-ID: <877f1m14we.fsf@garnerundergroundinc.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.2 (gnu/linux) Cancel-Lock: sha1:iLobMdwxiWLrRBvqIgfIspKCwvM= MIME-Version: 1.0 Content-Type: text/plain Lines: 15 X-Trace: sv3-5Csdln7kb6AaOB4t9XuOY6NzCdtalzrV1TbkkXh+h9ebqxx2OayQjcBEzBD/rUxkVXbClt1J3SLU+et!oNRP4zY/awFUkG1FUJLlAZIAK2CLlIYRjpofnMBYDkTFQmvKrjI75oEPEdU29Xp08/N1vCfv5xII!Iw== X-Complaints-To: www.supernews.com/docs/abuse.html X-DMCA-Complaints-To: www.supernews.com/docs/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 X-Original-Bytes: 1647 Xref: csiph.com comp.dsp:33795 I know next-to-nothing about this topic, but the following question has popped into my mind several times. It seems like folks generally (and perhaps this is totally wrong) design PID controllers by basically selecting what they think are "good" constants for the proportional, integral, and derivative terms. That is, they just sorta play with their systems and tweak the terms until it seems to work smoothly. However, how do you know that a particular configuration is stable? -- Randy Yates, Embedded Firmware Developer Garner Underground, Inc. 866-260-9040, x3901 http://www.garnerundergroundinc.com