Hello,

Given a system with redundant actuators, what would be the names of techniques that I could research to use each actuator for different frequency bands?

To illustrate the problem with a simple 1-dimensional problem, consider the attached picture. We have a mass m moving in 1-dimension connected to two redundant actuators. We want to regulate the position x while rejecting a disturbance Wd. In addition, we want to use the first actuator U1 to reject low frequency disturbances and the second actuator U2 for high frequency disturbances only. In other words, we do not want to use the second actuator U2 at steady state.

So far, I have come across Härkegård's work, such as [1], that explores dynamic control allocation. This discrete-time technique provides a way to penalise both high and low frequency usage of an actuator by adjusting the weighting matrices in its quadratic-programming cost function. They illustrate this technique by designing an aircraft control system for a fighter aircraft with a delta-canard configuration. The controller is designed to result in no canard deflection at trimmed flight to achieve low drag.

I am currently looking for other techniques that could be used to 'partition' the frequency usage of redundant actuators in order to get a more holistic view of the topic before committing to a single technique. I am looking at both techniques that separate the controller design and control allocation problems and ones that combine both.

Any suggestions of technique names or terms I could research would be much appreciated.

Thanks in advance for any suggestions.

Kind regards.

References

[1] Härkegård, Ola. (2004). Dynamic Control Allocation Using Constrained Quadratic Programming. Journal of Guidance Control and Dynamics. 27. 10.2514/1.11607. Article Dynamic Control Allocation Using Constrained Quadratic Programming