Clear Filters
Clear Filters

How to build a matrix with "sum" function in its elements?

2 views (last 30 days)
Hello everyone, I am building an mpc controller in matlab rather than using the built in 'mpc command'. I am facing some difficulties in building the mpc's matrices I thought about using for loop.my question is how to use for loop to generate these matrices? ...thanks in advance

Accepted Answer

Walter Roberson
Walter Roberson on 10 Apr 2020
Edited: Walter Roberson on 10 Apr 2020
Outline, not checked in detail against Su,b matrix requirements
CAn = Cb;
TCAn = 0;
TCAB = 0;
for K = 1 : p
%Sub
CAB = CAn * Bu;
TCAB = TCAB + CAB;
%now store TCAB into appropriate locations in Sub
insert storage code here
%Sxb
CAn = CAn * A;
TCAn = TCan + CAn;
%now store TCAN into appropriate locations in Sxb
end

More Answers (1)

Walter Roberson
Walter Roberson on 9 Apr 2020
sxb = C(b) .* cumsum(A.^(1:p)) .';
You might then want to
Sub = flipud(hankel(flipud(sxb)))
  3 Comments
Walter Roberson
Walter Roberson on 9 Apr 2020
If Cb is a matrix, then Sx,b would not be p x 1 as required by the diagram -- not even if A is also a matrix.
If A is a matrix, then for A^2 to exist then A would have to be a square matrix, same number of rows and columns. Call that m x m . Then if Cb is q x r, in order for Cb * A^2 to be scalar, either Cb and A are scalar, or else r = m and q x m * m x m -> q x m would have to be scalar, which could only happen if q = m = 1 so both scalar.
The logic is a bit different if A^n is intended ot indicate A.^n (each element individually raised to the power.) In such a case, if A is m x n then A.^2 would be m x n, and Cb * A^2 could be scalar if Cb is 1 x m and A is m x 1. Is that what is happening?
Mohamed Abdullah
Mohamed Abdullah on 10 Apr 2020
Edited: Mohamed Abdullah on 10 Apr 2020
I think the only way to make the dimension of 'Sxb' as (PX1) is to deal with the whole block 'Sxb' as a cellarray block containing matrices.for example, let's say p=3, A matrix has size of (mXm) with m=3 and Cb matrix has size of (qXm) with q= 2. if we dealt with 'Sxb' as a Matrix, the final size of it will be (qXp,m):
Sxb=[C*A;
C*A^2+C*A;
C*A^3+C*A^2+C*A];
I have succeeded to build 'Sxb' with for loop as follows:
Sxb=cell(3,1);
>> Sxb{1,1}=zeros(2,3);
>> for p=1:1:3
Sxb{p,1}= C*A^p+Sxb{1,1};
Sxb{1,1}=Sxb{p,1};
end
but I still need some help to figure out how to build the other two blocks 'Sub' and 'Sdb'.

Sign in to comment.

Categories

Find more on Model Predictive Control Toolbox in Help Center and File Exchange

Tags

Products


Release

R2016b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!