Experimental Implementation of a Nonlinear Dynamic Inversion Controller with Antiwindup

A recently proposed nonlinear antiwindup compensation scheme is implemented and tested on a 1/16 scaled BAeHawk jet trainer wind-tunnel model, mounted in a one degree of freedom configuration. The Hawk is modeled as anonlinear affine system subject to input amplitude constraints. The primary control system consists of an inner-loop nonlinear dynamic inversion controller and an outer-loop linear proportional integral derivative controller. The input constraints are addressed by supplementing this nominal controller with two types of nonlinear antiwindup schemes: a nonlinear variant of the well-known internal model control scheme and a suboptimal L2 norm-based antiwindup compensator. Wind tunnel results are presented which demonstrate the usefulness of the antiwindup schemes in preventing performance deterioration due to the input constraints and the flexibility of the proposed approach from a practical perspective.