🚀 go-pugleaf

						Joseph Maurice Rojas
						Hughes Research Laboratories
						Malibu, CA  90265
						(213) 317-5765
						rojas@math.berkeley.edu 
						rojas@aic.hrl.hac.com

						July 18, 1990

Dear colleagues,
	I was reading the paper "Stability Regions of Nonlinear Autonomous 
Dynamical Systems" by Chiang, Hirsch, and Wu (IEEE Transactions on Automatic
Control, vol. 33, No. 1, Jan. 1988) when I noticed that "autonomous" in the 
dynamical systems context meant non time-varying.  My summer work deals with 
the control of an autonomous submarine.  In the context of AI, "autonomous" 
means intelligent in some task-oriented sense.  My project is to define and 
characterize "instability" in the autonomous control logic of this submarine, 
and I would like to know if the ideas of the above paper have been generalized 
enough to include my project. 
	In particular, what is known about finding stability regions of 
time-varying systems?  What about systems with unknown time-varying parameters,
such as a submarine in unknown currents?  I apologize in advance for any 
abuse of terminology but control theory is not my strong point.  I'm actually
a math graduate student specializing in modular functions.  Any ideas or 
leads regarding stability regions of time-varying systems would be greatly 
appreciated.  Thank you in advance for your time.

						Sincerely, 

						Maurice

P.S.:  I realize this bulletin board may not be the best place for my topic, 
       but is there a sci.control-theory or something like that?  If so, please
       let me know!