Mercurial > octave-nkf
view scripts/control/base/dlqe.m @ 3431:99ab64f4a09d
[project @ 2000-01-14 03:53:03 by jwe]
author | jwe |
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date | Fri, 14 Jan 2000 04:12:41 +0000 |
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children | 9debe1be75a5 |
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## Copyright (C) 1993, 1994, 1995 Auburn University. All rights reserved. ## ## This file is part of Octave. ## ## Octave is free software; you can redistribute it and/or modify it ## under the terms of the GNU General Public License as published by the ## Free Software Foundation; either version 2, or (at your option) any ## later version. ## ## Octave is distributed in the hope that it will be useful, but WITHOUT ## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or ## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License ## for more details. ## ## You should have received a copy of the GNU General Public License ## along with Octave; see the file COPYING. If not, write to the Free ## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. ## -*- texinfo -*- ## @deftypefn {Function File} {[@var{l}, @var{m}, @var{p}, @var{e}] =} dlqe (@var{a}, @var{g}, @var{c}, @var{sigw}, @var{sigv}, @var{z}) ## Construct the linear quadratic estimator (Kalman filter) for the ## discrete time system ## @iftex ## @tex ## $$ ## x_{k+1} = A x_k + B u_k + G w_k ## $$ ## $$ ## y_k = C x_k + D u_k + w_k ## $$ ## @end tex ## @end iftex ## @ifinfo ## ## @example ## x[k+1] = A x[k] + B u[k] + G w[k] ## y[k] = C x[k] + D u[k] + w[k] ## @end example ## ## @end ifinfo ## where @var{w}, @var{v} are zero-mean gaussian noise processes with ## respective intensities @code{@var{sigw} = cov (@var{w}, @var{w})} and ## @code{@var{sigv} = cov (@var{v}, @var{v})}. ## ## If specified, @var{z} is @code{cov (@var{w}, @var{v})}. Otherwise ## @code{cov (@var{w}, @var{v}) = 0}. ## ## The observer structure is ## @iftex ## @tex ## $$ ## z_{k+1} = A z_k + B u_k + k (y_k - C z_k - D u_k) ## $$ ## @end tex ## @end iftex ## @ifinfo ## ## @example ## z[k+1] = A z[k] + B u[k] + k (y[k] - C z[k] - D u[k]) ## @end example ## @end ifinfo ## ## @noindent ## The following values are returned: ## ## @table @var ## @item l ## The observer gain, ## @iftex ## @tex ## $(A - ALC)$. ## @end tex ## @end iftex ## @ifinfo ## (@var{a} - @var{a}@var{l}@var{c}). ## @end ifinfo ## is stable. ## ## @item m ## The Riccati equation solution. ## ## @item p ## The estimate error covariance after the measurement update. ## ## @item e ## The closed loop poles of ## @iftex ## @tex ## $(A - ALC)$. ## @end tex ## @end iftex ## @ifinfo ## (@var{a} - @var{a}@var{l}@var{c}). ## @end ifinfo ## @end table ## @end deftypefn ## Author: A. S. Hodel <a.s.hodel@eng.auburn.edu> ## Created: August 1993 ## Modified for discrete time by R. Bruce Tenison (btenison@eng.auburn.edu) ## October, 1993 function [l, m, p, e] = dlqe (a, g, c, sigw, sigv, s) if (nargin != 5 && nargin != 6) error ("dlqe: invalid number of arguments"); endif ## The problem is dual to the regulator design, so transform to dlqr call. if (nargin == 5) [k, p, e] = dlqr (a', c', g*sigw*g', sigv); m = p; l = k'; else [k, p, e] = dlqr (a', c', g*sigw*g', sigv, g*s); m = p; l = k'; a = a-g*t/sigv*c; sigw = sigw-t/sigv; endif p = a\(m-g*sigw*g')/a'; endfunction