cnf_update_model.m

hard disk drive servo control tools, it is very helpful

% check the validity of the model based on the Entry
% *************************************************************************
function cnfdb = cnf_update_model(cdb)

cnfdb = cdb;
% 
cnfdb.sys_ok = 0;


% A
the_str = deblank(cnfdb.Entry.A);
if isempty(the_str)
    the_str='[]';
end    
IA=evalin('base',the_str,'[]');
[nx,na]=size(IA);
if nx<1 | nx~=na
   warndlg('The maxtrix A is not appropriate !', 'Warning ...', 'modal');
   uiwait;
   return;
end

% B
the_str = deblank(cnfdb.Entry.B);
if isempty(the_str)
    the_str='[]';
end    
IB=evalin('base',the_str,'[]');
if ~isequal(size(IB),[nx 1])
   warndlg('The maxtrix B is not appropriate !', 'Warning ...', 'modal');
   uiwait;
   return;
end


% C1
the_str = deblank(cnfdb.Entry.C1);
if isempty(the_str)
    the_str='[]';
end    
IC1=evalin('base',the_str,'[]');
[nm nc1]=size(IC1);
if nc1~=nx 
   warndlg('The maxtrix C1 is not appropriate !', 'Warning ...', 'modal');
   uiwait;
   return;
end
if nm~=rank(IC1) 
   warndlg('The maxtrix C1 is not of full row rank !', 'Warning ...', 'modal');
   uiwait;
   return;
end

% C2
the_str = deblank(cnfdb.Entry.C2);
if isempty(the_str)
    the_str='[]';
end    
IC2=evalin('base',the_str,'[]');
if ~isequal(size(IC2),[1 nx]) 
   warndlg('The maxtrix C2 is not appropriate !', 'Warning ...', 'modal');
   uiwait;
   return;
end

% D2
the_str = deblank(cnfdb.Entry.D2);
if isempty(the_str)
    the_str='[0]';
end    
ID2=evalin('base',the_str,'[]');
if ~isequal(size(ID2),[1 1]) 
   warndlg('The maxtrix D2 is not appropriate !', 'Warning ...', 'modal');
   uiwait;
   return;
end


% Check controllability and observability
% check for stabilizability
% RB=IB;
% RAB=RB;
% for n=1:nx-1,
%     RB=IA*RB;
%     RAB=[RAB RB];
% end
RAB=ctrb(IA,IB);
if rank(RAB)~=nx
   poles=eig(IA);
   nn=find(real(poles)>=0);
   for n=1:length(nn),
       XA=[IA-poles(nn(n))*eye(nx)  IB];
       if rank(XA)~=nx
           warndlg('The nominal model is not stabilizable !', 'Warning ...', 'modal');
           uiwait;
           return;
       end
   end 
end   
           
% % check for detectability
% % RC=IC1;
% % RAC=RC;
% % for n=1:nx-1,
% %     RC=RC*IA;
% %     RAC=[RAC; RC];
% % end
RAC=obsv(IA,IC1);
if rank(RAC)~=nx
   poles=eig(IA);
   nn=find(real(poles) >=0);
   for n=1:length(nn),
       XA=[IA-poles(nn(n))*eye(nx) ;  IC1];
       if rank(XA)~=nx
%            warndlg('The nominal model is not detectable !', 'Warning ...', 'modal');
%            uiwait;
%            break;           
%%           return;
       end
   end 
end   
       
% check for invertibility at s=0
if rank([-IA -IB; IC2 ID2])<nx+1
    warndlg('The nominal model has an invariant zero at s=0 !', 'Warning ...', 'modal');
    uiwait;
    return;
end
    

% initial condition x0
the_str = deblank(cnfdb.Entry.x0);
if isempty(the_str)
    x0=zeros(nx,1);
else    
    M = evalin('base',the_str,'[]');
    [nr,nc]=size(M);
    if nr==1
       xx=[M';zeros(nx,1)];
    else 
       if nr>1 
          xx=[M(:,1);zeros(nx,1)];
       else   
          xx=zeros(nx,1);
       end  
   end   
   x0=xx(1:nx);
%   warndlg('The initial state you just entered is of wrong dimension.','Warning ','modal');
end
cnfdb.System.x0=x0;


% for disturbance
% E
the_str = deblank(cnfdb.Entry.E);
if isempty(the_str)
    the_str='[]';
end    
IE=evalin('base',the_str,'[]');
[ne nw]=size(IE);
if ne~=nx & cnfdb.System.DT_in ==1
   warndlg('The maxtrix E is not appropriate !', 'Warning ...', 'modal');
   uiwait;
   return;
end   
cnfdb.System.DT_E=IE;
% w
the_str = deblank(cnfdb.System.DT_w);
if cnfdb.System.DT_in
    if isempty(the_str)
        the_str=matrix2str(zeros(nw,1));
    else    
        t = 0.1;
        if ~isequal(size(eval(the_str, '[]')), [nw 1])
            warndlg('The time function for disturbance is invalid !', 'Warning ...', 'modal');
            uiwait;
            return;
        end
    end
end
cnfdb.System.DT_w = the_str;


% for control saturation
the_str = deblank(cnfdb.Entry.Um);
if isempty(the_str)
    the_str='[]';
end    
Umax = evalin('base',the_str,'[]');
if cnfdb.System.CS_in & ( isempty(Umax) | Umax<=0)
   warndlg('The control saturation level is not appropriate !', 'Warning ...', 'modal');
   uiwait;
   return;
end    
cnfdb.System.CS_Umax=Umax;


% for resonance modes
the_str = deblank(cnfdb.Entry.RM);
if isempty(the_str)
    the_str='zpk(1)';
end    
cnfdb.System.RM=evalin('base',the_str,'[]');

if cnfdb.System.RM_in &  ~isa(cnfdb.System.RM, 'lti')
%    cnfdb.System.RM_in = 0;
   warndlg('The resonant modes should be formulated as an LTI model !', 'Warning ...', 'modal');
   uiwait;
   return;
end


% for input nonlinearity
NL_Fcn = deblank(cnfdb.System.NL_Fcn);
if isempty(NL_Fcn)
    if cnfdb.System.NL_in
        NL_Fcn='0';
    end
else   
    clear t;  % This to to aviod the confusion with disturbance w(t)
    y=ones(nm,1);
    if ~isequal(size(eval(NL_Fcn, '[]')), [1 1])
        warndlg({'The nonlinearity function you entered is invalid !', 'Please note that it must be a scalar one.'} , 'Warning ...', 'modal');
        uiwait;
        return;
    end
end
cnfdb.System.NL_Fcn = NL_Fcn;

% nonlinear zero dynamics
if cnfdb.System.QD_in==1
    QD_Fcn = cnfdb.System.QD_Fcn;
    Q0 = cnfdb.System.Q0;
    if isempty(QD_Fcn)| isempty(Q0)
        uiwait(msgbox('Please speicify the nonlinear zero dynamics and initial value.', get(gcf, 'Name'), 'help', 'modal'));
        return;  
    end    

    % nq=length(strfind(QD_Fcn,';'))+1;
    %     nh=size(IC2,1);
    %     h=zeros(nh,1);
    %     x=zeros(nx,1);
    x=cnfdb.System.x0;
    h=cnfdb.System.C2*x0;
    q=Q0;
    qdot=eval(QD_Fcn,'[]');
    if ~isequal(size(qdot),size(Q0)) | ( size(Q0,2) ~=1 )
        uiwait(msgbox('The nonlinear zero dynamics or the initial value are not appropriate.', get(gcf, 'Name'), 'help', 'modal'));
        return;  
    end
    
    %     % test the stability of the nonlinear zero dynamics
    %     tstep=cnfdb.StepSize;
    %     tstop=cnfdb.StopTime;
    %     tt=0;
    %     nn=0;
    %     QT=Q0; 
    %     while tt<tstop & nn<50
    %         [t1,qt] = ode45(@qdotfun,[0,tstep], QT, [], QD_Fcn);
    %         pt=length(t1);
    %         QT=qt(pt,:)';
    %         tt=tt+tstep;
    %         nn=nn+1;
    %     end
    %     if norm(QT)> norm(Q0)
    %         selection = questdlg({'It looks like the nonlinear zero dynamics is not stable..',...
    %                 'Do you still wish to continue ?'}, get(gcf, 'Name') , 'Yes','No','Yes');
    %         if strcmp(selection,'No')
    %             return;
    %         end
    %         %        uiwait(warndlg('It looks like the nonlinear zero dynamics is not stable.' , 'Warning ...', 'modal'));
    %         %        return;
    %     end
end    

cnfdb.sys_ok=1;
%  check whether there are any changes to the nominal model
if ~isequal(cnfdb.System.A, IA) | ~isequal(cnfdb.System.B, IB) | ~isequal(cnfdb.System.C1, IC1) | ... 
        ~isequal(cnfdb.System.C2, IC2) | ~isequal(cnfdb.System.D2, ID2)
    cnfdb.sys_ok = 2;
end

cnfdb.System.A=IA;
cnfdb.System.B=IB;
cnfdb.System.C1=IC1;
cnfdb.System.C2=IC2;
cnfdb.System.D2=ID2;


% %   Differential Equations of the nonlinear zero dynamics
% function qdot=qdotfun(t,qt, qf)
% q=qt;
% h=0;
% qdot = eval(qf);