www.gusucode.com > rctobsolete 工具箱 matlab源码程序 > rctobsolete/robust/@lti/private/mksys.m
function sys=mksys(varargin)
% LTI/PRIVATE/MKSYS creates an LTI object SYS from system data matrices.
% SYS=MKSYS(A,B,C,D) or
% SYS=MKSYS(V1,V2,...,VN, TY) packs matrices describing a system into
% variable SYS depending on the STRING TY as follows:
% ----- ------------------------------- ---------------------------
% TY V1,V2,...,VN Description
% ----- ------------------------------- ---------------------------
% 'ss' 'a,b,c,d[,Ts],ty' Standard Statespace (default)
% 'des' 'a,b,c,d,e[,Ts],ty' Descriptor System
% 'tss' 'a,b1,b2,c1,c2,d11,d12,d21,d22[,Ts],ty' Two-port Statespace
% 'tdes' 'a,b1,b2,c1,c2,d11,d12,d21,d22,e[,Ts],ty'Two-port Descriptor
% 'gss' 'sm,dimx,dimu,dimy[,Ts],ty' General statespace
% 'gdes' 'e,sm,dimx,dimu,dimy[,Ts],ty' General descriptor
% 'gpsm' 'psm,deg,dimx,dimu,dimy[,Ts],ty' General polynom. sys. matrix
% 'tf' 'num,den[,Ts],ty' Transfer function
% 'tfm' 'num,den,m,n[,Ts],ty' Transfer function matrix
% 'imp' 'y,ts,nu,ny[,Ts],ty' Impulse response
% ----------------------------------------------------------------------
% The optional input Ts (sampling time), if non-zero, tags the system as
% discrete-time; a negative Ts=-1 indicates sampling time is unspecified.
% The BRANCH function recovers matrices packed into S, e.g., the 'c'
% and 'a' matrices from a standard statespace system S are returned by
% the command [C,A,Ts]=BRANCH(S,'c,a,Ts'). Alternatively, the command
% [AG,BG,CG,DG,TY]=BRANCH(S) returns the matrices (except for Ts)
% in the order in which they were originally packed.
%
% LTI/PRIVATE/MKSYS uses same syntax as the function MKSYS, but differs
% in that it produces an LTI object output SYS in most cases.
%
% See also BRANCH, SSDATA, TFDATA, LTI, MKSYS
% R. Y. Chiang & M. G. Safonov (9/21/97)
% Revised 4/3/98 M. G. Safonov
% Copyright 1988-2004 The MathWorks, Inc.
% ---------------------------------------------------------------------------
nin=nargin;
Ts=0; % default sampling time
% Determine TY and set NIN equal to number of input arguments other than TY
if nin<1
error('Too few input arguments')
else
%% eval(['ty=v' num2str(nin) ';'])
ty=varargin{nin};
if isstr(ty), % If TY is present
nin=nin-1;
else
ty='ss'; % Default TY='ss' if last argument is not a string
end
end
% Verify validity of TY
[vars,nvars]=vrsys(ty);
% Get optional input Ts, if present
temp=varargin{nin};
if nvars<nin & isa(temp,'double') & length(temp)==1,
Ts=temp;
nin=nin-1;
end
if nvars>nin,
error(['Too few input arguments for MKSYS type ' ty]),
elseif nvars<nin,
error(['Too many input arguments for MKSYS type ' ty]),
end
% Convert TY to lowercase
ty=lower(ty);
switch ty
case {'ss'}
% 'ss' 'a,b,c,d,ty' Standard Statespace (default)
sys=ss(varargin{1:nin});
case {'des','dss'}
% 'des' 'a,b,c,d,e,ty' Descriptor System
if rcond(varargin{5}) < eps, % bypass singular E-matrix bug in lti/dss
% warning('Singular E matrix: using mksys(A,B,C,D,E,''des'') instead of dss(A,B,C,D,E)')
sys=mksys(varargin{1:nin},'des');
else
sys=dss(varargin{1:nin});
end
case {'tss'}
% 'tss' 'a,b1,b2,c1,c2,d11,d12,d21,d22,ty' Two-port Statespace
sys=tss(varargin{1:nin});
case {'tdes','tdss'}
% 'tdes' 'a,b1,b2,c1,c2,d11,d12,d21,d22,e,ty'Two-port Descriptor
if rcond(varargin{10}) < eps, % bypass singular E-matrix bug in lti/dss
% warning('Singular E matrix: using mksys instead of LTI')
sys=mksys(varargin{1:nin},'tdes');
else
sys=tss(varargin{1:nin-1});
set(sys,'e',varargin{nin});
end
case {'tf'}
% 'tf' 'num,den,ty' SIMO Transfer function
num=varargin{1};
den=varargin{2};
[rnum]=size(num,1);
if rnum >1 & size(den,1)==1, % If den is scalar poly,
den=ones(rnum,1)*den; % then make it same size as num poly vector
end
num=num2cell(num,2);
den=num2cell(den,2);
sys=tf(num,den);
case {'tfm'}
% 'tfm' 'num,den,n,m,ty' MIMO nxm transfer function matrix
nummat=varargin{1};
denmat=varargin{2};
rtfm=varargin{3};
ctfm=varargin{4};
[rnum]=size(nummat,1);
if rnum >1 & size(denmat,1)==1, % If den is scalar poly,
denmat=ones(rnum,1)*denmat; % then make it same size as num poly vector.
end
num=cell(rtfm,ctfm); % Form empty cells arrays
den=cell(rtfm,ctfm);
num(:)=num2cell(nummat,2); % then fill with data from rows of num
den(:)=num2cell(denmat,2); % and rows of den.
sys=tf(num,den);
case {'gss','gdes','gpsm','imp'} % Types with no LTI equivalent
%% ASSEMBLE SYS USING OLD PRE-LTI RCT TREE VECTOR METHOD:
%%
% 'gss' 'sm,dimx,dimu,dimy,ty' General statespace
% 'gdes' 'e,sm,dimx,dimu,dimy,ty' General descriptor
% 'gpsm' 'psm,deg,dimx,dimu,dimy,ty' General polynom. sys. matrix
% 'imp' 'y,ts,nu,ny' Impulse response
sysmagic=27591; % number installed in any system TREE in position 4
% to distinguish SYS from ordinary tree vectors
vars = [vars ',ty'];
temp=[];
sys=tree(vars,varargin{1:nin},ty);
sys(4)=sysmagic;
otherwise
error(['Unknown system type ''' ty '''']),
end
if isa(sys,'lti'),
set(sys,'Ts',Ts);
elseif Ts,
sys=graft(sys,Ts,'Ts');
end
% -------- End LTI/PRIVATE/MKSYS.M -----------RYC/MGS 1997 %
function sys=tss(a,b1,b2,c1,c2,d11,d12,d21,d22)
% SYS= TSS(A,B1,B2,C1,C2,D11,D12,D21,D22) transforms TITO system
% (two-input-two-output) state-space matrices
% A,B1,B2,C1,C2,D11,D12,D21,D22
% into the corresponding partitioned LTI object. TSS
% is the inverse of the function TSSDATA.
%
% See also TSSDATA, MKTITO
% R. Y. Chiang & M. G. Safonov
b=[b1,b2];
c=[c1;c2];
d=[d11,d12; d21, d22];
[msg,a,b,c,d]=abcdchk(a,b,c,d);
sys=ss(a,b,c,d);
[nmeas,ncont]=size(d22);
sys=mktito(sys,nmeas,ncont);
% ----------- End of TSS.M --------RYC/MGS 1997
function sys=mktito(sys,nmeas,ncont)
% SYS=MKTITO(SYS,NMEAS,NCONT) adds TITO partitioning to
% a system by re-setting its InputGroup and
% OutputGroup properties, labeling last NMEAS
% output channels 'measurement' and the last NCONT input
% channels 'command'. Other output and input channels
% are labeled 'error' and 'disturbance', respectively.
% Any pre-existing partition of SYS is overwritten.
% R. Y. Chiang & M. G. Safonov
% Based on Gahinet's 01/98 partitioning specification
[r,c]=size(sys);
if ~isa(sys,'lti'), error('SYS is not an LTI object'), end
if r<nmeas, error('NMEAS exceeds SYS output dimension'), end
if c<ncont, error('NCONT exceeds SYS input dimension'), end
% set(sys,'InputGroup',{ 1:c-ncont 'U1'; c-ncont+1:c 'U2' });
% set(sys,'OutputGroup',{ 1:r-nmeas 'Y1'; r-nmeas+1:r 'Y2'});
set(sys,'InputGroup', struct('U1', 1:c-ncont, 'U2', c-ncont+1:c));
set(sys,'OutputGroup',struct('Y1', 1:r-nmeas, 'Y2', r-nmeas+1:r));
% ----------- End of MKTITO.M --------RYC/MGS 1997