MATLAB: Invalid dimensions between blocks in Simulink

errormatrixsimulink

Hi!
I'm struggling with the error message of invalid dimensions between two blocks – see figure from simulink.
The gain block uses matrix Bd(set to matrix multiplication(K*u)) which is a 5×2 matrix. The random number has nothing fancy with it, in this case just noise. I've tried using the Signal Specification block as seen above to make the signal appear as a 1×5 vector, but this fails in the same manner.
The errors say "output port widths or dimensions of the Signal specification is a [1×5] matrix"
and "Invalid dimensions specified for input port of gain. Gain has dimensions [5×2] while input is set to dimensions [1×5]. These dimensions is not suitable for matrix product with the input signal"
Any helpers who could help here? Much appreciated!

Best Answer

Do you want a 1x5 array of different random numbers, or the same 5 times?
Either way, if you have u=[1x5] and Bd=[5x2], then you need u*Bd, not Bd*u.
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