Supporting custom tunning goals for 'systune' function

I want to see if there is a way to use custom tuning goal for ‘systune’ function.

Specifically, I am trying to optimize a controller to jointly reduce output disturbance and measurement noise. The objective is framed by minimizing the sum of two components:

1. The residual effect of output disturbance, which amounts to the infinity norm of a weighted sensitivity function

2. The residual effect of sensor measurement noise on the output, which is the 2-norm of the complementary sensitivity function.

Instead of specifying independent tuning goals, I want to make a custom tuning goal by summing the two goals together.

Answer 1

[MathWorks Support Team]

As of R2019b, this is a limitation for control design objectives. The only option in R2019b is to include the available tuning goals separately while calling the 'systune' function as a vector of tuning goal objects.

For the particular workflow described, the ‘Disturbance Rejection Goal’ appears to be a good candidate. Disturbance Rejection Goal specifies the minimum attenuation of a disturbance injected at a specified location in a control system. For more details, please check the following link:  

https://www.mathworks.com/help/releases/R2019b/control/ug/disturbance-rejection-goal.html  

In addition, there is an example describing how to use frequency-domain requirements, which include the "Disturbance Rejection Goal". As demonstrated in the "Disturbance Rejection" section in the example: 

https://www.mathworks.com/help/releases/R2019b/slcontrol/ug/frequency-domain-specifications.html  

you can specify a desired frequency-domain expression for the disturbance attenuation.

The development team is aware of this limitation for  custom tuning goals, and will consider adding this functionality in a future release.