I am not sure but I think your statement corresponds to our observation that a sub which is depth controlled by its rudders, will start porpoising (going up and down) when forward speed exceeds a certain limit. Did you check out those URL's ? are you allowed to buy a depth controller instead of making one ? regards, Ronald van Aalst ----- Original Message ----- From: Peter L. Peres To: Sent: Wednesday, September 17, 2003 10:12 PM Subject: Re: Tuning a PID Algorithm > Try to look at self-tuning pid loops. It's fairly simple, one applies a > unit pulse on the control input and observes the feedback over time. From > this the necessary corrections can be computed or iterated to. However, if > your pid loop controls something with *any* kind of deadband you will face > difficult times. And there are *no* mechanical controls without a > deadband. > > Peter > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email listserv@mitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body