Design of stability augmentation system using μ-synthesis

Abstract

It is described how the μ-synthesis method was used to design a controller for the HIRM benchmark problem. Controllers for the longitudinal and lateral axes were designed. For the longitudinal axis a fixed-gain controller was designed, but for the lateral axis designs were carried out for a low and a high angle of attack flight case. The main conclusions concerning the use of μ-synthesis are: Handling qualities requirements as formulated in the HIRM problem can easily be incorporated in the design. Robustness to modelling errors can be handled in a straightforward way whereas robustness due to variations in flight case can be more difficult to include. It may be a bit difficult to choose weighting transfer functions that reflect the requirements in an appropriate way, and quite some time is spent on tuning the weighting transfer functions.