Model Predictive Control with Time Delay Compensation

[Steffen Mann]

Dear All,

My system has a varying time delay with a nominal delay of about 7 s and I want to consider that in my model predictive controller.

I am not really sure how to implement a time delay compensation for a model predicitve controller in YALMIP. 

Does anyone have an example code to give me a better understanding (or some literature)? Or can anyone give me an extension of the

code in Simulink models with YALMIP for this model with an additional time delay?

Thank you for any help! 

[Johan Löfberg]

time-delay just means you have to add more states

x(k+1) = Ax(k) + Bu(k-1) would be x(k+1) = Ax(k)+B*newstate(k), newstate(k+1) = u(k) etc

i.e., in discrete time nothing really happens compared to standard case

[Steffen Mann]

Dear Johan,

thank you! Simple as that!

So I only have to expand my control input vector, save the last control inputs over my time delay and

add them as

lastu(k) == u(k)

as a constraint for the length of my time delay. 

Best Regards

Steffen

[Johan Löfberg]

you expand the state vector,not the control