Disturbance estimator utilized in simscape example ee_pmsm_position_control

Hello, I have been following the provided example for Simscape electrical ee_pmsm_position_control,

focusing in the outer position control loop,

The example in mathworks page is not thoroughly documented, aside from a script in which the variables for the model are defined and briefly described, there is not much additional detail provided.

I'm familiar with LQR controller theory and state estimation, yet I'm not able to follow up with how the computation of the TqRef input is performed,

The script that accompanies the example defines a M matrix that is utilized for multiplying with a vector composed of ThetaReq and an state of the observer, what is this matrix for? and what are the states of the observer for which another is used for feedback? Which references can I reach for in this topic?

% Extended state-space system used for disturbance estimation
Ae = [0.5,0,0,0;0.125,0.998125,0,-0.125;0,0.001,1,0;0,0,0,1]; 
Be = [0.5;0;0;0];
Ce = [0,1,0,0;0,0,1,0];
De = [0;0];

% Luenberger observer matrix
L = [-0.608695623566427,0.000608083406529464;...
    1.75899463909956,-0.000509401369300945;...
    0.000999979537685081,0.250000875019145;...
    -7.99999999983601,0.00598686601578727];

% Matrix for computing steady-state values of state and control inputs in
% the outer loop controller
M = [1,0;2.66453525910038e-15,0;0,1;1,0];

Answer 1

[abraham rodriguez]

I just found the paper from which the example is based on, It will be nice if it could be added in the documentation page for it:

Speed Control of PMSM Based on an Optimized

ADRC Controller

https://www.hindawi.com/journals/mpe/2019/1074702/

[abraham rodriguez]

The correct paper from which the example is basd on is the following

https://ieeexplore.ieee.org/document/8515606