[general] Numerical Analysis Seminar

krj@utcsri.UUCP (Ken Jackson) (08/23/85)

		Numerical Analysis Seminar

	Solving Stiff ODEs with Coupled Algebraic Equations
		on a Microcomputer System

		Per Grove Thomsen
		Technical University of Denmark

Date: 	Tuesday, August 27, 1985.
Time:	3:10 p.m.
Place:	Sandford Fleming Building, Room 3207, 
	University of Toronto

The typical problem in the design of engineering control systems leads
to coupled algebraic and differential equations where the system may
change at well-defined set-points.  Mathematically, the problem will be
that of solving a system of the form
	y' = f(y,z,t),   h(y,z,t) = 0,  y(t0) = y0,  h(y0,z0,t0) = 0,
where y is the vector of dynamic variables and z is the vector of state
variables.  The set-points are equivalent to points of discontinuity.

The implementation is based on SDIRK methods with coupled algebraic
equations and special interpolation formulae for smooth continuation
of the solution and location of the discontinuities.  The programming
language is Pascal and the implementation runs on a 64K microcomputer.