findulb.m

国外专家做的求解LMI鲁棒控制的工具箱,可以相对高效的解决LMI问题

function [lb,ub,cand_rows] = findulb(F_struc,K)
%FINDULB Internal function to extract upper and lower variable bounds

% Author Johan L鰂berg
% $Id: findulb.m,v 1.2 2004/07/02 08:17:30 johanl Exp $

n = size(F_struc,2)-1;
lb = -inf*ones(n,1);
ub = inf*ones(n,1);
cand_rows = [];
if (K.l ~=0)
    
    A = -F_struc(K.f+1:K.f+K.l,2:end);
    b = F_struc(K.f+1:K.f+K.l,1);
    
    
    n = size(F_struc,2)-1;
    
    cand_rows = find(sum(A~=0,2)==1);
    for i = 1:length(cand_rows)
        j = find(A(cand_rows(i),:));
        if A(cand_rows(i),j)>0
            ub(j)=min(ub(j),b(cand_rows(i))/A(cand_rows(i),j));
        else
            lb(j)=max(lb(j),b(cand_rows(i))/A(cand_rows(i),j));
        end
    end
end