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

[Ali]

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

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

[Hiromasa]

Thank you for your question.

As the error text suggests, the error comes from dimension conflicts between a port and a block.

Ctrl+D updates the Simulink model and shows the signal deminsion as below. The exmaple below also shows the same error messages. You see "?" on input signal and output signal for State Space block. This is because State Space block expects 3 dimension signal while Input port demension is set to 2. Similarly, the dimension conflict occurs between Mux and Outpout port.

You may want to update the dimensions of either ports and/or State Space block to resolve this dimension conflict. Hope this information helps.