Dimensions of matrices being concatenated are not consistent

Hello,

I am trying to add in a State-Space Block into simulink with the following matrices:

However I recieve the following error whenever i try to apply this:

Where am i going wrong.

[Geoff Hayes]

Matthew - which matrices are being multiplied together? A is 3x3 and B is 3x1; C is 4x3 and D is 4x1. Do your initial input need to be a 3x1 array? (I'm just guessing here...is this the x in the equations?)

[Matthew Tarn]

Thankyou in advanced for your reply.

I have calculated the matrices by hand to meet parameters for a State-Variable feedback controller on paper and would like to test my calculations in matlab/simulink.

The following is a picture of the circuit i am trying to design and input my matricies/gains into, I also have 3 pole positions determined:

I have expanded C from a 1x3 matrix to a 4x3 matrix and D from a 1x1 matrix to a 4x1 matrix; to give myself 3 more outputs instead of just 1 output from the original C and D so that when the data is output i can see part 1 on the scope and parts 2,3 and 4 can be multiplied by a gain matrix I have.

I have got the size of the matricies that i need from this information on:https://uk.mathworks.com/help/simulink/slref/statespace.html

Matt

Answer 1

[Geoff Hayes]

Matt - from your above description, C is an rxn matrix and D is an rxm matrix where r is the number of outputs. Doesn't this mean that your Initial Outputs must be a 4x1 array?

[Matthew Tarn]

Yes thats correct Geoff, is it as simple as putting 4*1 into the “initial outputs“ box and 1*1 into the initial inputs box?

Again, Thank you for your responses so far.

Matt

[Geoff Hayes]

Hopefully that should be enough. Have you tried it out?