Can we equate or un-equate the two MV's of the MPC controller in command line?

Hi

I have the system with 2inputs, 1output, in that I need to give the constraints for 2MV's and the constraint range(min&max) of those 2MV's is same. but I need to give the condition that, MV1 should not be equal to the MV2. can I give this condition in MPC command line coding? please suggest me.

Thank you in advance..

Answer 1

[Emmanouil Tzorakoleftherakis]

Hello,

A couple of points first:

1) I am assuming your MVs are continuous (if they are discrete, what you are asking is not supported because you would need a mixed-integer NLP solver and Model Predictive Control Toolbox does not have one out of the box yet).

2) A constraint of the form MV1 ~= MV2 does not make much sense for floating point calculations. So basically you can just design your linear MPC without this constraint and it is very unlikely that MV1 == MV2 considering again numerics etc. So I am assuming that you want the 2 MVs to be significantly different, for example |MV1-MV2|>= 0.1.

This kind of constraint you cannot implement with linear MPC, so you have to use nonlinear MPC (see how to create custom constraints here) With that in mind, you can do something like sqrt((MV1-MV2)^2) >=0.1 or equivalent.

Hope that helps

[Sarala Gurijala]

Thank you so much for your response sir.. for MV1~=MV2 I will go with nonlinear MPC.

But for the other case MV1 > MV2, where MV1 and MV2 both has to be in the range of 0 to 1. Can

I use linear MPC?

[Emmanouil Tzorakoleftherakis]

For a constraint like this, you could use linear MPC and set up the constraints as shown here.

[Sarala Gurijala]

@Emmanouil Tzorakoleftherakis thank you sir