Integration of Phase Plane Flight Envelope Protections in Cascaded Incremental Flight Control

With advances in incremental non-linear flight control, new challenges and possibilities for incorporating efficient flight envelope protections arise. Investigation of a phase plane based command and virtual control limiting pitch angle protection in the reference model of a cascaded incremental backstepping controller is performed for a commercial aircraft model. This provides an almost model free design of a combined flight control law and envelope protection. Verification through simulation shows that accurate predictable response behaviour is obtained close to the limit, which permits a protection that minimizes the interference into the nominal control.