Tartalomjegyzék

LPV output passivization

Teljes Matlab script kiegészítő függvényekkel.

File: d2018_01_09_K_prelim_L_codesign_v4.m
Directory: projects/3_outsel/2017_11_13_lpv_passivity
Author: Peter Polcz (ppolcz@gmail.com)
Created on 2018. January 09.
Modified on 2018. January 17.
Modified on 2018. January 25.

1. lépés: Legyen egy LTI rendszermodell

FIGYELEM, a rendszermodell, nem stabil!

s = tf('s');

% unstable MIMO
H = @(s) [
    (s-1)/(s-2)/(s+1)  1/(s+3)/(s-0.1)
    (s-7)/(s+1)/(s+5)  (s-6)/(s^2+5*s+6)
    ];

sys = minreal( ss( H(s) ) );
[A0,B,C,D] = deal(sys.a, sys.b, sys.c, sys.d);

tol = 1e-10;
prec = -log10(tol);

A0 = round(A0,prec);
B = round(B,prec);
C = round(C,prec);
D = round(D,prec);

[POLES,ZEROS] = pzmap(sys)
Output:
2 states removed.
POLES =
   -5.0000
   -1.0000
    2.0000
   -3.0000
   -2.0000
    0.1000
ZEROS =
   5.8894 + 0.0000i
  -4.3164 + 0.0000i
   0.7635 + 0.7978i
   0.7635 - 0.7978i
\begin{align} {\LARGE(1) \quad} H(s) = \left(\begin{array}{cc} -\frac{s-1}{-s^2+s+2} & \frac{10}{10s^2+29s-3} \\ \frac{s-7}{s^2+6s+5} & \frac{s-6}{s^2+5s+6} \\ \end{array}\right) \end{align}

2. lépés: LPV modell

Az előző LTI modellt egy kicsit megperturbálom (kezdetben csak az A mátrixot).

$$ \begin{aligned} &\Sigma: \left\{\begin{aligned} &\dot x = A(\rho) x + B(\rho) u,~~~ \rho \in \mathcal P \\ &y = C x \\ \end{aligned}\right. \\ &\begin{aligned} \text{where: } & A(\rho) = A_0 + A_1 \rho \in \mathbb{R}^{n\times n} \\ & B(\rho) = B_0 + B_1 \rho \in \mathbb{R}^{n\times r} \\ & C \in \mathbb{R}^{m\times n} \\ & D = 0_{m\times r} \end{aligned} \end{aligned} $$

rho_lim = [
    -1 1
    ];

A1 = A0;
A1(abs(A0) < 1) = 0;
A1 = A1 .* randn(size(A1))/10;

B0 = B;
B1 = B*0;
% Indices = [3];
% B1(Indices) = rand(size(Indices));

A_fh = @(rho) A0 + rho*A1;
B_fh = @(rho) B0 + rho*B1;
\begin{align} {\LARGE(2) \quad} A_0 = \left(\begin{array}{cccccc} -5.37 & -0.933 & -0.464 & 0.0928 & 0.464 & 0.464 \\ 1.87 & -0.319 & -0.188 & 0.0375 & 0.188 & 0.188 \\ -0.292 & -0.731 & -1.35 & 0.29 & -1.55 & -1.55 \\ 0.0585 & 0.146 & 0.224 & 0.0552 & 0.276 & 0.276 \\ 0.292 & 0.731 & -3.19 & 0.638 & -1.81 & 0.188 \\ 0.292 & 0.731 & 0.101 & -0.0203 & 1.9 & -0.101 \\ \end{array}\right) ,\quad A_1 = \left(\begin{array}{cccccc} 0.128 & 0 & 0 & 0 & 0 & 0 \\ 0.043 & 0 & 0 & 0 & 0 & 0 \\ 0 & 0 & -0.121 & 0 & 0.0261 & -0.19 \\ 0 & 0 & 0 & 0 & 0 & 0 \\ 0 & 0 & -0.0927 & 0 & -0.0981 & 0 \\ 0 & 0 & 0 & 0 & 0.0739 & 0 \\ \end{array}\right) \end{align} \begin{align} {\LARGE(3) \quad} B_0 = \left(\begin{array}{cc} 2 & 0 \\ 0 & 0 \\ 1.15 & 2 \\ -0.229 & 0 \\ -1.15 & 2 \\ -1.15 & 0 \\ \end{array}\right) ,\quad B_1 = \left(\begin{array}{cc} 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ \end{array}\right) \end{align} \begin{align} {\LARGE(4) \quad} C = \left(\begin{array}{cccccc} 0.169 & 0.422 & 0.256 & 0.949 & -0.256 & -0.256 \\ 0.701 & -1.25 & -0.444 & 0.0889 & 0.944 & -1.06 \\ \end{array}\right) ,\quad D = \left(\begin{array}{cc} 0 & 0 \\ 0 & 0 \\ \end{array}\right) \end{align}

Observer design

Declare matrices

Matrix $K$ is preliminarily design for the nominal value of $\rho$, than checked whether the closed loop is stable for other $\rho \in \mathcal P$ values. Let $G = I_m$.

G = eye(n_u);
K = place(A0,B,linspace(-5,-6,n_x));

Free matrix variables. All matrices are assumed to be parameter independent.

C1 = sdpvar(n_yp,n_x,'full');
D1 = sdpvar(n_yp,n_y,'full');
Q = sdpvar(n_x,n_x,'symmetric');
S = sdpvar(n_x,n_x,'symmetric');
N = sdpvar(n_x,n_y,'full');
P = blkdiag(Q,S);

where $N = S L$.

$$ \begin{align} &\wt A(\rho) = \pmqty{ A(\rho) & 0 \\ 0 & A(\rho) - L C },~ \wt B = \pmqty{B \\ 0} \\ &\wt C = \pmqty{ D_1 C + C_1 & -C_1 }. \end{align} $$

Ao = @(L,rho) [
    A_fh(rho)         zeros(n_x,n_x)
    zeros(n_x,n_x)    A_fh(rho)-L*C
    ];
Bo = @(rho) [B_fh(rho) ; zeros(n_x,n_u)];
Co = [D1*C+C1 -C1];
Do = zeros(n_yp,n_r);

$$ \begin{aligned} \wt A_c(\rho) = \begin{pmatrix} A(\rho)-B(\rho) K & B(\rho) K \\ 0 & A(\rho) - L C \end{pmatrix},~ \wt B_c(\rho) = \begin{pmatrix} B(\rho) G \\ 0 \end{pmatrix}. \end{aligned} $$

Ac = @(L,rho) [
    A_fh(rho)-B_fh(rho)*K  B_fh(rho)*K
    zeros(n_x,n_x)         A_fh(rho)-L*C
    ];

Bc = @(rho) Bo(rho)*G;

W = eye(n_yp);

$$ \begin{aligned} &\wt A_c({\color{red} \rho})^T P + P \wt A_c({\color{red} \rho}) = \spmqty{ {\blue Q} A_K({\red \rho}) + A_K^T({\red \rho}) {\blue Q} & {\blue Q} B({\red \rho}) K \\ K^T B^T({\red \rho}) {\blue Q} & {\blue S} A({\red \rho}) + A({\red \rho})^T {\blue S} - {\blue N}({\red \rho}) C - C^T {\blue N^T}({\red \rho}), } \\ &\text{where } A_K({\red \rho}) = A({\red \rho}) - B({\red \rho}) K. \nonumber \end{aligned} $$

AcP_PAc = @(rho) [
    Q*(A_fh(rho)-B_fh(rho)*K)+(A_fh(rho)-B_fh(rho)*K)'*Q , Q*B_fh(rho)*K
    K'*B_fh(rho)'*Q                                      , S*A_fh(rho)+A_fh(rho)'*S-N*C-C'*N'
    ];

$$ M_2 = \spmqty{ { \wt A_c({\color{red} \rho})^T} { P} + { P} { \wt A_c({\color{red} \rho})} & { P} \wt B_c({\red \rho}) - { \wt C^T({\red \rho})} & { \wt C^T({\red \rho})} \\ \wt B_c^T({\red \rho}) { P}- { \wt C({\red \rho})} & 0 & 0 \\ { \wt C({\red \rho})} & 0 & -W^{-1} } $$

M2 = @(rho) [
    AcP_PAc(rho)     P*Bc(rho)-Co'     Co'
    Bc(rho)'*P-Co    zeros(n_r,n_r)    zeros(n_r,n_yp)
    Co               zeros(n_yp,n_r)   -inv(W)
    ];

% Constraints
Constraints = [
    M2(rho_lim(1)) <= 0
    M2(rho_lim(2)) <= 0
    P - 0.0001*eye(size(P)) >= 0
    ]
Output:
++++++++++++++++++++++++++++++++++
|   ID|                Constraint|
++++++++++++++++++++++++++++++++++
|   #1|   Matrix inequality 16x16|
|   #2|   Matrix inequality 16x16|
|   #3|   Matrix inequality 12x12|
++++++++++++++++++++++++++++++++++

Solve the optimization problem

optimize(Constraints)
check(Constraints)

Q = value(Q);
S = value(S);
N = value(N);
L = S\N;
P = value(P);
Co = value(Co);
C1 = value(C1);
D1 = value(D1);
Output:
Problem
  Name                   :                 
  Objective sense        : min             
  Type                   : CONIC (conic optimization problem)
  Constraints            : 70              
  Cones                  : 0               
  Scalar variables       : 0               
  Matrix variables       : 3               
  Integer variables      : 0               

Optimizer started.
Presolve started.
Linear dependency checker started.
Linear dependency checker terminated.
Eliminator - tries                  : 0                 time                   : 0.00            
Lin. dep.  - tries                  : 1                 time                   : 0.00            
Lin. dep.  - number                 : 0               
Presolve terminated. Time: 0.00    
Problem
  Name                   :                 
  Objective sense        : min             
  Type                   : CONIC (conic optimization problem)
  Constraints            : 70              
  Cones                  : 0               
  Scalar variables       : 0               
  Matrix variables       : 3               
  Integer variables      : 0               

Optimizer  - threads                : 4               
Optimizer  - solved problem         : the primal      
Optimizer  - Constraints            : 70
Optimizer  - Cones                  : 0
Optimizer  - Scalar variables       : 0                 conic                  : 0               
Optimizer  - Semi-definite variables: 3                 scalarized             : 350             
Factor     - setup time             : 0.00              dense det. time        : 0.00            
Factor     - ML order time          : 0.00              GP order time          : 0.00            
Factor     - nonzeros before factor : 2485              after factor           : 2485            
Factor     - dense dim.             : 0                 flops                  : 4.63e+05        
ITE PFEAS    DFEAS    GFEAS    PRSTATUS   POBJ              DOBJ              MU       TIME  
0   2.4e+00  1.0e+00  5.0e+00  0.00e+00   3.998800000e+00   0.000000000e+00   1.0e+00  0.00  
1   5.1e-01  2.2e-01  2.3e+00  1.00e+00   8.653260980e-01   0.000000000e+00   2.2e-01  0.01  
2   1.7e-01  7.3e-02  1.4e+00  9.99e-01   2.928667199e-01   0.000000000e+00   7.3e-02  0.01  
3   6.5e-02  2.7e-02  8.2e-01  9.96e-01   1.092859917e-01   0.000000000e+00   2.7e-02  0.01  
4   2.6e-02  1.1e-02  5.2e-01  9.96e-01   4.359699912e-02   0.000000000e+00   1.1e-02  0.01  
5   6.5e-03  2.7e-03  2.6e-01  9.93e-01   1.106114712e-02   0.000000000e+00   2.7e-03  0.01  
6   1.2e-03  4.9e-04  1.1e-01  9.83e-01   1.983690263e-03   0.000000000e+00   4.9e-04  0.01  
7   3.7e-04  1.6e-04  6.0e-02  9.66e-01   6.497328863e-04   0.000000000e+00   1.6e-04  0.01  
8   1.0e-04  4.3e-05  3.1e-02  9.72e-01   1.792048672e-04   0.000000000e+00   4.3e-05  0.02  
9   3.7e-05  1.5e-05  1.8e-02  9.61e-01   6.549183771e-05   0.000000000e+00   1.5e-05  0.02  
10  1.1e-05  4.5e-06  9.3e-03  9.37e-01   1.963054462e-05   0.000000000e+00   4.5e-06  0.02  
11  3.8e-06  1.6e-06  5.1e-03  8.75e-01   7.332408972e-06   0.000000000e+00   1.6e-06  0.02  
12  1.0e-06  4.4e-07  2.2e-03  7.86e-01   2.163809803e-06   0.000000000e+00   4.4e-07  0.02  
13  4.0e-07  1.7e-07  1.1e-03  5.87e-01   9.458365393e-07   0.000000000e+00   1.7e-07  0.02  
14  1.1e-07  4.5e-08  3.7e-04  4.42e-01   2.401016369e-07   0.000000000e+00   4.5e-08  0.02  
15  4.2e-08  1.8e-08  1.6e-04  2.27e-01   4.545620214e-08   0.000000000e+00   1.8e-08  0.02  
16  1.1e-08  4.6e-09  4.6e-05  1.82e-01   -9.180751529e-08  0.000000000e+00   4.6e-09  0.02  
17  3.7e-09  1.6e-09  1.5e-05  4.56e-02   -1.688411463e-07  0.000000000e+00   1.6e-09  0.03  
18  9.9e-10  4.2e-10  4.6e-06  1.05e-01   -1.624759075e-07  0.000000000e+00   4.2e-10  0.03  
19  3.3e-10  1.4e-10  1.3e-06  -4.15e-02  -2.373727832e-07  0.000000000e+00   1.4e-10  0.03  
20  7.8e-11  3.3e-11  3.7e-07  8.04e-02   -1.847140321e-07  0.000000000e+00   3.3e-11  0.03  
21  2.5e-11  1.1e-11  1.1e-07  -4.23e-02  -2.418477399e-07  0.000000000e+00   1.1e-11  0.03  
22  5.9e-12  2.5e-12  2.8e-08  4.44e-02   -2.014976492e-07  0.000000000e+00   2.5e-12  0.03  
23  2.3e-12  9.6e-13  9.9e-09  -2.33e-02  -2.318494891e-07  0.000000000e+00   9.6e-13  0.03  
24  5.6e-13  2.4e-13  2.5e-09  1.39e-02   -2.143400718e-07  0.000000000e+00   2.4e-13  0.04  
25  1.9e-13  8.3e-14  8.5e-10  2.36e-02   -2.133640503e-07  0.000000000e+00   7.8e-14  0.04  
26  8.7e-14  4.0e-14  3.9e-10  -2.92e-02  -2.242798185e-07  0.000000000e+00   3.7e-14  0.04  
27  2.2e-14  1.1e-14  1.0e-10  4.02e-02   -2.048706677e-07  0.000000000e+00   9.4e-15  0.04  
28  1.5e-14  4.5e-15  3.2e-11  -5.15e-02  -2.423431259e-07  0.000000000e+00   3.2e-15  0.04  
29  5.7e-15  3.8e-15  8.6e-12  3.29e-02   -1.991483253e-07  0.000000000e+00   7.8e-16  0.04  
30  1.1e-14  2.9e-15  3.3e-12  7.07e-03   -2.168408055e-07  0.000000000e+00   3.0e-16  0.04  
31  1.9e-14  4.0e-15  8.0e-13  -5.50e-02  -2.151847642e-07  0.000000000e+00   7.7e-17  0.04  
32  1.5e-14  5.1e-15  3.2e-13  5.05e-02   -2.044214007e-07  0.000000000e+00   2.9e-17  0.04  
33  1.4e-14  3.6e-15  7.7e-14  -2.12e-03  -2.112498488e-07  0.000000000e+00   7.1e-18  0.05  
34  1.6e-14  5.8e-15  3.5e-14  1.94e-02   -2.020719376e-07  0.000000000e+00   3.1e-18  0.05  
35  1.7e-14  5.3e-15  8.7e-15  1.05e-02   -2.073297244e-07  0.000000000e+00   7.9e-19  0.05  
36  1.6e-14  6.7e-15  2.7e-15  1.44e-02   -2.079595344e-07  0.000000000e+00   2.5e-19  0.05  
37  4.8e-15  5.2e-15  8.1e-16  -8.84e-03  -2.086795478e-07  0.000000000e+00   7.4e-20  0.05  
38  1.9e-15  4.2e-15  3.2e-16  3.66e-02   -2.085400886e-07  0.000000000e+00   2.9e-20  0.05  
39  4.9e-16  3.3e-15  8.2e-17  -2.18e-02  -2.122872776e-07  0.000000000e+00   7.6e-21  0.06  
40  2.0e-16  4.9e-15  3.4e-17  2.60e-02   -2.094344730e-07  0.000000000e+00   3.1e-21  0.06  
41  4.8e-17  7.6e-15  7.9e-18  -2.70e-02  -2.157591766e-07  0.000000000e+00   7.5e-22  0.06  
42  2.2e-17  5.8e-15  3.7e-18  8.82e-03   -2.153702299e-07  0.000000000e+00   3.5e-22  0.06  
43  5.2e-18  8.1e-15  8.5e-19  -4.88e-02  -2.191924415e-07  0.000000000e+00   8.5e-23  0.07  
44  2.6e-18  4.9e-15  4.3e-19  5.61e-02   -2.166711047e-07  0.000000000e+00   4.2e-23  0.07  
45  6.2e-19  8.6e-15  1.0e-19  -3.17e-02  -2.216121230e-07  0.000000000e+00   1.0e-23  0.07  
46  2.5e-19  9.2e-15  4.1e-20  4.33e-02   -2.139068091e-07  0.000000000e+00   4.1e-24  0.07  
47  5.0e-19  5.8e-15  9.5e-21  -1.19e-02  -2.222423383e-07  0.000000000e+00   9.8e-25  0.07  
48  2.6e-17  5.8e-15  8.8e-21  2.28e-02   -2.220289699e-07  0.000000000e+00   9.0e-25  0.08  
49  3.7e-17  5.1e-15  8.1e-21  1.67e-02   -2.219344403e-07  0.000000000e+00   8.3e-25  0.08  
50  3.9e-17  5.3e-15  8.0e-21  1.60e-02   -2.219318921e-07  0.000000000e+00   8.2e-25  0.08  
51  3.9e-17  5.8e-15  8.0e-21  1.44e-02   -2.219313216e-07  0.000000000e+00   8.2e-25  0.09  
52  3.9e-17  5.8e-15  8.0e-21  1.45e-02   -2.219313216e-07  0.000000000e+00   8.2e-25  0.09  
Optimizer terminated. Time: 0.10    


Interior-point solution summary
  Problem status  : PRIMAL_AND_DUAL_FEASIBLE
  Solution status : OPTIMAL
  Primal.  obj: -2.2193132163e-07   nrm: 3e+09    Viol.  con: 3e-07    barvar: 1e-07  
  Dual.    obj: 0.0000000000e+00    nrm: 3e+09    Viol.  con: 0e+00    barvar: 3e-06  
Optimizer summary
  Optimizer                 -                        time: 0.10    
    Interior-point          - iterations : 53        time: 0.09    
      Basis identification  -                        time: 0.00    
        Primal              - iterations : 0         time: 0.00    
        Dual                - iterations : 0         time: 0.00    
        Clean primal        - iterations : 0         time: 0.00    
        Clean dual          - iterations : 0         time: 0.00    
    Simplex                 -                        time: 0.00    
      Primal simplex        - iterations : 0         time: 0.00    
      Dual simplex          - iterations : 0         time: 0.00    
    Mixed integer           - relaxations: 0         time: 0.00    

ans = 
  struct with fields:

    yalmiptime: 0.1801
    solvertime: 0.1077
          info: 'Successfully solved (MOSEK)'
       problem: 0
 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
|   ID|          Constraint|   Primal residual|   Dual residual|
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
|   #1|   Matrix inequality|       -3.2315e-07|      4.5921e-17|
|   #2|   Matrix inequality|       -1.7472e-07|      1.3704e-16|
|   #3|   Matrix inequality|        2.4208e-05|      5.8803e-17|
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 

Validate solution

Output:
[  OK  ] M2(0) <= 0
[  OK  ] M2(0.1) <= 0
[  OK  ] M2(-0.1) <= 0
[  OK  ] P > 0
[  OK  ] A - LC < 0
[  OK  ] norm(D1) > 1e-3
[  OK  ] Zeros of the open loop system are stable
[  OK  ] Zeros of the closed loop system are stable

Zero dynamics of the obtained LPV

Construct LPV model matrices

Written on 2018. January 17.

Ebben a részben $A(\rho)$, $B(\rho)$, $C$, $D$ új értelmet nyer. Ezek adják meg az observerrel kiegészített dinamika mátrixait.

A_fh = @(rho) Ao(L,rho);
B_fh = Bo;

A0 = A_fh(0);
A1 = A_fh(1) - A0;

B0 = B_fh(0);
B1 = B_fh(1) - B0;

C0 = Co;
C1 = C0*0;

D0 = Do;
D1 = Do*0;

A_fh = @(rho) A0 + A1*rho;
B_fh = @(rho) B0 + B1*rho;
C_fh = @(rho) C0 + C1*rho;
D_fh = @(rho) D0 + D1*rho;

A = {A0, A1};
B = {B0, B1};
C = {C0, C1};
D = {D0, D1};

AA = [A{:}];
BB = [B{:}];
\begin{align} {\LARGE(5) \quad} A(\rho) = \left(\begin{array}{cccccccccccc} 0.13\rho -5.4 & -0.93 & -0.46 & 0.093 & 0.46 & 0.46 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0.043\rho +1.9 & -0.32 & -0.19 & 0.038 & 0.19 & 0.19 & 0 & 0 & 0 & 0 & 0 & 0 \\ -0.29 & -0.73 & -0.12\rho -1.4 & 0.29 & 0.026\rho -1.5 & -0.19\rho -1.5 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0.059 & 0.15 & 0.22 & 0.055 & 0.28 & 0.28 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0.29 & 0.73 & -0.093\rho -3.2 & 0.64 & -0.098\rho -1.8 & 0.19 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0.29 & 0.73 & 0.1 & -0.02 & 0.074\rho +1.9 & -0.1 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0 & 0 & 0 & 0 & 0 & 0 & 0.13\rho +2.6 & -0.87 & 1.6 & 19.0 & 1.7 & -12.0 \\ 0 & 0 & 0 & 0 & 0 & 0 & 0.043\rho +11.0 & -1.1 & 1.9 & 22.0 & 2.2 & -14.0 \\ 0 & 0 & 0 & 0 & 0 & 0 & -25.0 & 0.22 & -0.12\rho -7.2 & -57.0 & 0.026\rho -6.0 & 35.0-0.19\rho \\ 0 & 0 & 0 & 0 & 0 & 0 & 9.7 & -0.18 & 2.6 & 23.0 & 2.0 & -14.0 \\ 0 & 0 & 0 & 0 & 0 & 0 & 29.0 & -1.1 & 3.4-0.093\rho & 68.0 & 4.0-0.098\rho & -44.0 \\ 0 & 0 & 0 & 0 & 0 & 0 & 27.0 & -1.4 & 5.9 & 61.0 & 0.074\rho +7.5 & -40.0 \\ \end{array}\right) \end{align} \begin{align} {\LARGE(6) \quad} B(\rho) = \left(\begin{array}{cc} 2.0 & 0 \\ 0 & 0 \\ 1.1 & 2.0 \\ -0.23 & 0 \\ -1.1 & 2.0 \\ -1.1 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ \end{array}\right) \end{align} \begin{align} {\LARGE(7) \quad} C(\rho) = C = 10^{-3} \left(\begin{array}{cccccccccccc} 0.23 & -0.21 & 0.37 & 1.4 & -0.15 & -0.59 & 0.24 & 0.35 & -0.17 & -0.11 & 0.12 & -0.11 \\ 0.099 & 0.069 & 0.68 & 0.79 & 0.09 & 0.22 & -4.410^{-3} & 0.24 & -0.5 & -0.17 & -0.28 & -0.37 \\ \end{array}\right) \end{align}

Nálam az $E_c$ most az $Im(B)$.

Im_B = IMA([B{1} B{2}]);
\begin{align} {\LARGE(8) \quad} \mathrm{Im}\big(B(\rho)\big) = \left(\begin{array}{cc} -0.707 & 0 \\ 0 & 0 \\ -0.406 & -0.707 \\ 0.0811 & 0 \\ 0.406 & -0.707 \\ 0.406 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ \end{array}\right) \end{align}
Ker_C = INTS(KER(C{1}), KER(C{2}));
\begin{align} {\LARGE(9) \quad} \mathrm{Ker}(C) = \left(\begin{array}{cccccccccc} -0.991 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ -0.0188 & 0.978 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0.0217 & -0.0604 & -0.837 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0.112 & 0.0919 & 0.26 & 0.446 & 0 & 0 & 0 & 0 & 0 & 0 \\ -0.0141 & -0.0395 & 0.0778 & 0.1 & 0.974 & 0 & 0 & 0 & 0 & 0 \\ -0.0544 & -0.134 & 0.229 & 0.469 & -0.191 & 0.531 & 0 & 0 & 0 & 0 \\ 0.0208 & 0.0393 & -0.0398 & -0.233 & 0.0622 & 0.469 & -0.826 & 0 & 0 & 0 \\ 0.0272 & 0.0157 & 0.0886 & -0.465 & 0.0502 & 0.475 & 0.428 & 0.563 & 0 & 0 \\ -0.0073 & 0.0609 & -0.281 & 0.417 & 0.0433 & 0.126 & 0.0189 & 0.344 & -0.648 & 0 \\ -0.0074 & 0.0118 & -0.0877 & 0.199 & 0.0003 & -0.0667 & -0.0835 & 0.335 & 0.415 & -0.799 \\ 0.0146 & 0.0684 & -0.189 & 0.0186 & 0.0794 & 0.49 & 0.355 & -0.637 & 0.081 & -0.233 \\ -0.0045 & 0.0458 & -0.206 & 0.295 & 0.0339 & 0.11 & 0.0287 & 0.215 & 0.633 & 0.554 \\ \end{array}\right) \end{align}

We compute $\mathcal V^*$ and $\mathcal R^*$.

[R,V] = CSA([A{1} A{2}], Im_B, Ker_C);

dim_V = size(V,2);
dim_Ker_V = size(V,1) - size(V,2);

assert(rank(R) == 0 && rank([V Ker_C]) == rank(Ker_C), ...
    'Strong invertibility condition is not satisfied!');
assert(rank(INTS(V, Im_B)) == 0)

We ensure that $\mathcal R^* = \{0\}$ and that $\mathcal V^* \subseteq \mathrm{Ker}(C)$. Furthermore, we checked the strong invertibility condition $\mathcal V^* \cap \mathrm{Im}\big(B(\rho)\big) = \{0\}$.

\begin{align} {\LARGE(10) \quad} \mathcal V^* = \left(\begin{array}{cccccccccc} -0.991 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ -0.0188 & 0.978 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0.0217 & -0.0604 & -0.837 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0.112 & 0.0919 & 0.26 & 0.446 & 0 & 0 & 0 & 0 & 0 & 0 \\ -0.0141 & -0.0395 & 0.0778 & 0.1 & 0.974 & 0 & 0 & 0 & 0 & 0 \\ -0.0544 & -0.134 & 0.229 & 0.469 & -0.191 & 0.531 & 0 & 0 & 0 & 0 \\ 0.0208 & 0.0393 & -0.0398 & -0.233 & 0.0622 & 0.469 & -0.826 & 0 & 0 & 0 \\ 0.0272 & 0.0157 & 0.0886 & -0.465 & 0.0502 & 0.475 & 0.428 & 0.563 & 0 & 0 \\ -0.0073 & 0.0609 & -0.281 & 0.417 & 0.0433 & 0.126 & 0.0189 & 0.344 & -0.648 & 0 \\ -0.0074 & 0.0118 & -0.0877 & 0.199 & 0.0003 & -0.0667 & -0.0835 & 0.335 & 0.415 & -0.799 \\ 0.0146 & 0.0684 & -0.189 & 0.0186 & 0.0794 & 0.49 & 0.355 & -0.637 & 0.081 & -0.233 \\ -0.0045 & 0.0458 & -0.206 & 0.295 & 0.0339 & 0.11 & 0.0287 & 0.215 & 0.633 & 0.554 \\ \end{array}\right) \end{align}

State transformation invariant feedback design

1. variáns

Let $T = \begin{pmatrix} {V^*}^\perp & L \end{pmatrix}^T$, where ${V^*}^\perp$ and $L$ are orthonormal bases for ${\mathcal V^*}^\perp \not\perp \mathcal L \subseteq \mathrm{Im}\big(B(\rho)\big)$, respectively.

L = ORTCO(Im_B);
dim_L = size(L,2);

assert(dim_L >= dim_V);

T = [ ORTCO(V) L(:,1:dim_V) ]';
\begin{align} {\LARGE(11) \quad} {\mathcal V^*}^\perp = \left(\begin{array}{cc} 0.135 & 0 \\ -0.138 & -0.157 \\ 0.16 & -0.52 \\ 0.827 & -0.171 \\ -0.104 & -0.153 \\ -0.401 & -0.477 \\ 0.153 & 0.107 \\ 0.2 & -0.0819 \\ -0.0541 & 0.428 \\ -0.0546 & 0.123 \\ 0.108 & 0.33 \\ -0.0334 & 0.316 \\ \end{array}\right) \end{align} \begin{align} {\LARGE(12) \quad} \mathcal L = \left(\begin{array}{cccccccccc|} -0.707 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0.406 & 0 & -0.414 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ -0.0811 & 0 & -0.159 & 0.981 & 0 & 0 & 0 & 0 & 0 & 0 \\ -0.406 & 0 & 0.414 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ -0.406 & 0 & -0.795 & -0.196 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0 & 0 & 0 & 0 & -1 & 0 & 0 & 0 & 0 & 0 \\ 0 & 0 & 0 & 0 & 0 & -1 & 0 & 0 & 0 & 0 \\ 0 & 0 & 0 & 0 & 0 & 0 & -1 & 0 & 0 & 0 \\ 0 & 0 & 0 & 0 & 0 & 0 & 0 & -1 & 0 & 0 \\ 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & -1 & 0 \\ 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 1 \\ \end{array}\right) \end{align} \begin{align} {\LARGE(13) \quad} T^T = \left(\begin{array}{cc|cccccccccc} 0.135 & 0 & -0.707 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ -0.138 & -0.157 & 0 & 1 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0.16 & -0.52 & 0.406 & 0 & -0.414 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0.827 & -0.171 & -0.0811 & 0 & -0.159 & 0.981 & 0 & 0 & 0 & 0 & 0 & 0 \\ -0.104 & -0.153 & -0.406 & 0 & 0.414 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ -0.401 & -0.477 & -0.406 & 0 & -0.795 & -0.196 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0.153 & 0.107 & 0 & 0 & 0 & 0 & -1 & 0 & 0 & 0 & 0 & 0 \\ 0.2 & -0.0819 & 0 & 0 & 0 & 0 & 0 & -1 & 0 & 0 & 0 & 0 \\ -0.0541 & 0.428 & 0 & 0 & 0 & 0 & 0 & 0 & -1 & 0 & 0 & 0 \\ -0.0546 & 0.123 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & -1 & 0 & 0 \\ 0.108 & 0.33 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & -1 & 0 \\ -0.0334 & 0.316 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 1 \\ \end{array}\right) \end{align}

Transformed LPV system

tol = 1e-10;
prec = -log10(tol);

N = numel(A);
tA = cell(1,N);
tB = cell(1,N);
tC = cell(1,N);
tD = cell(1,N);

for i = 1:numel(A)
    tA{i} = round(T*A{i}/T, prec);
    tB{i} = round(T*B{i}, prec);
    tC{i} = round(C{i}/T, prec);
    tD{i} = round(D{i}, prec);
end

tA_fh = @(rho) tA{1} + tA{2}*rho;
tB_fh = @(rho) tB{1} + tB{2}*rho;
tC_fh = @(rho) tC{1} + tC{2}*rho;
tD_fh = @(rho) tD{1} + tD{2}*rho;
\begin{align} {\LARGE(14) \quad} \bar A_{22}(\rho) = \left(\begin{array}{cc|ccccccccc} -0.063\rho -1.8 & 0.012\rho +0.48 & -8.110^{-3}\rho -0.34 & 0.039-0.09\rho & -0.036\rho -0.55 & -0.015\rho -8.3 & 7.910^{-3}\rho +0.92 & 0.055\rho -1.0 & -8.510^{-3}\rho -20.0 & -0.022\rho -2.0 & -0.061\rho -13.0 \\ 1.0-0.025\rho & 0.1\rho -2.5 & 1.6-0.025\rho & 0.1\rho -1.5 & 0.15\rho -11.0 & 2.0-0.026\rho & 2.4-0.028\rho & -2.810^{-3}\rho -0.23 & 5.010^{-3}\rho -0.54 & 1.6-0.024\rho & 3.110^{-3}\rho +0.088 \\ \hline 8.410^{-3}\rho +0.3 & -0.042\rho -2.0 & 0.015\rho +0.23 & -0.013\rho -0.45 & -0.089\rho -3.2 & 0.016\rho +0.59 & 0.019\rho +0.7 & -1.910^{-3}\rho -0.067 & -4.510^{-3}\rho -0.16 & 0.014\rho +0.49 & 7.210^{-4}\rho +0.026 \\ 0.15\rho +3.7 & 5.710^{-3}\rho -0.14 & 0.027\rho +0.48 & -0.2\rho -3.0 & 0.92-0.031\rho & 0.021\rho +0.29 & -6.110^{-3}\rho -0.45 & 0.062\rho +1.6 & 0.017\rho +0.49 & 0.052\rho +1.1 & -0.046\rho -1.2 \\ 0.023\rho -0.14 & 2.910^{-3}\rho +5.410^{-3} & 5.710^{-3}\rho -0.019 & -0.02\rho -0.29 & -0.012\rho -0.036 & 4.810^{-3}\rho -0.011 & 1.210^{-3}\rho +0.017 & 8.910^{-3}\rho -0.063 & 2.010^{-3}\rho -0.019 & 9.210^{-3}\rho -0.044 & 0.046-6.710^{-3}\rho \\ 0 & 0 & 0 & 0 & 0 & 0.13\rho +2.6 & -0.87 & 1.6 & 19.0 & 1.7 & 12.0 \\ 0 & 0 & 0 & 0 & 0 & 0.043\rho +11.0 & -1.1 & 1.9 & 22.0 & 2.2 & 14.0 \\ 0 & 0 & 0 & 0 & 0 & -25.0 & 0.22 & -0.12\rho -7.2 & -57.0 & 0.026\rho -6.0 & 0.19\rho -35.0 \\ 0 & 0 & 0 & 0 & 0 & 9.7 & -0.18 & 2.6 & 23.0 & 2.0 & 14.0 \\ 0 & 0 & 0 & 0 & 0 & 29.0 & -1.1 & 3.4-0.093\rho & 68.0 & 4.0-0.098\rho & 44.0 \\ 0 & 0 & 0 & 0 & 0 & -27.0 & 1.4 & -5.9 & -61.0 & -0.074\rho -7.5 & -40.0 \\ \end{array}\right) \end{align} \begin{align} {\LARGE(15) \quad} \bar B(\rho) = \left(\begin{array}{cc} 0.84 & 0.11 \\ 0.17 & -1.3 \\ \hline 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ 0 & 0 \\ \end{array}\right) \end{align} \begin{align} {\LARGE(16) \quad} \bar C(\rho) = C = 10^{-3} \left(\begin{array}{cc|cccccccccc} 1.7 & -0.18 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ 0.73 & -1.1 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ \end{array}\right) \end{align}

Check stability of the transformed system

tP = T' \ P / T;

tP22 = tP(dim_Ker_V+1:end,dim_Ker_V+1:end);

for rho = rho_lim
    tA_rho = tA_fh(rho);

    tA22 = tA_rho(dim_Ker_V+1:end,dim_Ker_V+1:end);

    eig(tP22 * tA22 + tA22' * tP22)
end
Output:
ans =
   1.0e+09 *
   -2.0433
   -0.9166
   -0.7192
   -0.5903
   -0.4123
   -0.0797
   -0.0000
   -0.0000
   -0.0000
   -0.0000
ans =
   1.0e+09 *
   -2.3565
   -0.8375
   -0.6957
   -0.5840
   -0.4172
   -0.0936
   -0.0000
   -0.0000
   -0.0000
   -0.0000