Abstract: This application addresses the problems of large runway space occupation and potential airport traffic congestion during turning in current aircraft ground coordinated turning control methods. It proposes an aircraft ground coordinated turning system, and a sliding mode control method and system thereof. Based on real-time parameters of an aircraft, the state of the aircraft ground coordinated turning system is controlled on a composite sliding mode surface for nose wheel-main wheel coordinated turning through a nose wheel-main wheel coordinated turning control law. Specifically, a model for the aircraft ground coordinated turning system is developed. Aiming at the control problem in the traditional aircraft ground turning phase, and considering the problems such as oversteering of the nose landing gear and a large turning radius in the traditional nose wheel steering technology. Through coordinated turning of the nose wheel and main wheels, the turning radius is effectively reduced.

Abstract: A compound rotor aircraft, comprises a fuselage, a lifting rotor, wings and thrust propellers, wherein the fuselage has a cabin for driving; the lifting rotor is configured to drive the fuselage to move in the vertical direction; a plurality of wings are provided and arranged symmetrically on the two sides of the fuselage; a plurality of thrust propellers are provided and arranged on the plurality of wings respectively, and are configured to provide horizontal thrust force to the fuselage to drive the aircraft to move in the horizontal direction. The aircraft has various flight modes such as helicopter mode, compound helicopter mode, gyrocopter mode, compound gyrocopter mode and fixed-wing cruising mode, and can be transited among the modes. In the case of power failure of the lifting rotor, the aircraft can be transited into a gyrocopter state and continue the flight safely.