do stateflow support Vector State Machine Judgment

HI！ man&madam：

I'm working on a design for a group of devices that perform the same control strategy based on their terminal voltages, i.e., normal control strategy when the voltage is above a threshold, and fault strategy when the voltage is below a threshold, so I'd like to build a state flow model for control and easy for others to understand, but I'm having trouble outputting the corresponding unit states, and I've tried to add state{idx}=0; to make it a vector instead of a state. How do I set the state so that it is a vector instead, I tried to add state{idx}=0; to initialize it but the system says idx cannot be defined.

I uploaded a demo with three elements and his current output is correct, but the state is one-dimensional data.

Thank you for all！

[dai bowei]

sorry，the current output is also incorrect，its always under normal control，how can i fix it :(

Answer 1

[Alan]

Hi Dai,

I’m not able to understand the transition logic you used in the Stateflow diagram. "Vt" is a vector and you put transition conditions “Vt<0.9” and “Vt>=0.9”.

The above figure contains 3-scopes:

1. Scope2: Plots the voltage ‘Vt’
2. StateVector: I’ll explain this later
3. Scope1: Plots the state

As you can see in Scope2, at T=1, Vt = [0.5 1 0.3]

Vt < 0.9 will result in [1 0 1]

And, according to the window named Scope 1, state=0. This indicates that Stateflow only transitions to “state=1” if “Vt < 0.9” gives a result containing 1 in all indices. Since the vector “Vt < 0.9” will contain 3 logical elements, it will take 8 Stateflow blocks (2^3) to indicate each value assumed by the vector, along with a lot of transitions, which could get cumbersome. Instead, I suggest you use a “Relational Operator” block to simplify the logic like this:

The highlighted section contains the blocks I’ve added. The “Relational Operator” block has the operation set to “<”, and the scope named “StateVector” will give the output as shown in the window named “StateVector” as shown in the previous picture. I hope that scope shows your desired output.

For more information on the Relational Operator block, you can refer to the following MathWorks documentation: https://www.mathworks.com/help/simulink/slref/relationaloperator.html

Regards.

[dai bowei]

Thank you, Alan.

My original idea was to do the vector calculation in state flow with (idx) as index of the loop calculation, but I found that if I set it up this way, matlab suggests that idx must be an external input variable. But this is against my purpose, I want to use one state flow controller to control multiple devices at the same time independently. I've already achieved what I wanted with the matlab fuction module, but the stateflow module makes it easier to show other people what I'm trying to do. Your idea is great too, thanks again!

[Alan]

You're welcome! Glad to hear that you found another solution too.