Civil Aircraft Vertical Segment Smooth Transition and High-Precision Flight Guidance in Vertical Navigation Mode

Vertical segment transition is an important function of flight management system for civil aircraft, as it allows for smooth changes in the aircraft's vertical profile, thereby improving passenger comfort. In this paper, the issue of civil airliner vertical segment smooth transition and high-precision flight guidance is addressed. Firstly, a smooth transition strategy for vertical segment switching based on the flight path angle deviation in vertical navigation mode is developed. Subsequently, the vertical guidance law is designed, and an improved active disturbance rejection control-based robust pitch attitude controller is designed to respond to the generated guidance command. Through simulations, the results show that the introduced vertical segment transition strategy can effectively reduce the normal overload during segment switching, and the designed guidance law can achieve high-precision vertical guidance.