How to solve this error?

I keep getting this error while running the state space model,

Error in port widths or dimensions. Output port 1 of 'statespacemodel_hvm/Mux' is a one dimensional vector with 2 elements.

Error in port widths or dimensions. Input port 1 of 'statespacemodel_hvm/State-Space' has 3 elements. This port does not accept the dimensions (or orientation) specified by the input signal.

Please help me with this.

[Azzi Abdelmalek]

Priya, you've just showed the error message, How are we supposed to know what is in your model?

[Azzi Abdelmalek]

No, you can do it in this forum

[Priyatham Ganta]

Can you help me specifically in this.. When i simulate this model, there's always an error

Answer 1

[Anuj]

You are getting this error because your matrix dimensions are conflicting. Make sure that the dimensions of matrices in inputs and outputs must agree.

[Priya]

Thank you. Now I get another error saying

Error using horzcat Dimensions of matrices being concatenated are not consistent.

Please tell what does this mean?

[Walter Roberson]

You have something of the form

 [A B]

where A has a different number of rows than B has.

[Priya]

What function is used to define the input matrix B which is of size 14x2? The size of matrix A is 14x14. If I give it as B=zeros(size(A,1),2), I get a blank line at zero. Why is this so?

The result of B shows two columns of zeros using the above function. But I need some value for the B matrix. I'm bit confused about this.

Please do help me.

[Anuj]

You need to define your B matrix according to system input, If you define it as B=zeros(size(A,1),2), all elements of B will be zero. I hope this helps.

[Priya]

Ok. If I need the B matrix to be defined as the difference of the input and the wheelset's position (in my case it is the track input fed to the lateral position of the wheelset),do I have to design it in the model or give it in the mfile(ie., in the B matrix).

Since the state space model in Simulink consists of a track input(as step signal) given to the state space block with a mux.

[Anuj]

You can define it as you want, it depends on how you want to simulate it and how you find to do it easy.

Answer 2

[Ta An Vo]

I also have the same error. Please help me solve.

Answer 3

[Raghav Gopal Rao Netrakanti]

Hi.

I am unable to solve this problem on my end as well.

Description:

I have a discrete state space system of 2 states, 2 inputs and 2 outputs. i.e all A B C D matrices are all 2 by 2. I used the discrete state space block and entered the values. Now my two inputs are 9400 by 1 vectors and i used the constant block to send them as input from the workspace. I have tried with mux and vector concantenate blocks, tried transpose but every time i get the same type of error

"Error in port widths or dimensions. Output port 1 of 'untitled/constant2' is a [9400x2] matrix

"Error in port widths or dimensions. Input port 1 of 'untitled/Discrete State-Space' has 2 elements. This port does not accept the dimensions (or orientation) specified by the input signal."

I hope someone can point out the mistake.

Regards,

Gopal

[Walter Roberson]

If your inputs are 9400 x 1 vectors and you are working with 2 x 2 arrays, then I guess you have two of the 9400 x 1 vectors as inputs, representing the two different inputs for "2 inputs and 2 outputs" ?

What output size are you expecting for this 9400 x 1 vector(s) ?If you are expecting to reduce it to 1 x 2 or 2 x 1 then you would need a state space system with 9400 rows or columns in some of the matrices

Answer 4

[Tilakarathna K R]

sir im getting this error pls help me out

[Walter Roberson]

Simulink cannot tell what the actual size of the input is for From2, but knows it is at least 3 elements. That value is feeding into the second input of the MUX, which where it is expected to be only a single element.

You can probably get further by defining exact sizes for some of the ports instead of marking them as "inherit"

[Dmitriy Ogureckiy]

How make that?

[Walter Roberson]

https://www.mathworks.com/help/simulink/slref/signalspecification.html

Answer 5

[Ali]

Helllo everyone. I am having the same error. Im trying to model the inverter. but the same error is happening all the time