----- Original Message ----- From: Spehro Pefhany To: Sent: Thursday, February 22, 2001 9:56 AM Subject: Re: [EE]: PID controllers (was PWM motor control) > At 07:16 AM 2/22/01 -0500, you wrote: > > > >Does anybody have any good references/sources for such an adaptive system? > > Bob, > > There are probably a lot more references than working systems. This kind > of continously adaptive (stochastic, fuzzy-neural, model-adaptive) > control has been bandied about in the literature for over 20 years. > (as opposed to the type which deliberately perturbs the system and > uses Z-N or other methods to tune the controller, which is much > easier to accomplish). > > From what I've seen, what's out there in the literature won't work > well without a LOT of work, and the few that do work are proprietary > or only work with a very limited problem domain, or both. > > You might get better results by focusing on the elements of the > problem, improving the performance (and eliminating variations in) > the individual parts of your system. This could involve smarts, and > maybe additional sensors (a la fuzzy control) or it could just involve > mechanical improvements. Unfortunately, since we are only responsible for the control system we have _no_ control over the rest of the system (the generator, gate, hydraulics, etc.). We do have inputs for such thing as temps, load, etc. > > One time I had a car in which the steering got gradually looser and > looser, to the point where the steering wheel could be turned 1/4 turn > almost and nothing would happen at the front wheels. Being run by a > superb adaptive control system (me), I hardly noticed the change. > Then someone else tried to drive my car, and could barely keep in > the proper lane. A crank of a wrench and the requirements for the > control system were drastically reduced. Yikes! > Best regards, > Spehro Pefhany Bob Ammerman RAm Systems (contract development of high performance, high function, low-level software) -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics