Patent ID: 11921521
Assignee: VOLOCOPTER GMBH
Field: Transport (Mechanical engineering)
Classification: CPC G  B | IPC B  G

Claim 12:
13. A method of controlling an aircraft having multiple configurations, the method comprising:
controlling each said configuration by a control law implemented by a flight controller, wherein:
a first configuration includes a copter mode of the aircraft controlled by a first control law, when in the copter mode the aircraft performs at least one of vertical take-off, landing, hover, turn on a spot, climb or descent, with relatively low horizontal velocities;
a second configuration includes a jet mode of the aircraft controlled by a second control law, when in the jet mode the aircraft performs at least one of level flight, turn flights, climb or descent, with relatively higher horizontal velocities than in said copter mode; and
a threshold value for said horizontal velocity in a forward direction is defined for differentiating between said copter mode and jet mode;
estimating the horizontal velocity relative to surrounding air of the aircraft using a pilot control input relating to a forward motion, by:
normalizing said pilot control input;
low-pass filtering said pilot control input;
using said low-pass filtered and normalized pilot input as an estimated normalized forward speed; and
assigning a threshold for the estimated normalized forward speed in order to determine when to switch from the copter mode to the jet mode, and vice versa; and

transitioning from the first configuration to the second configuration by gradually blending out the first control law for the first configuration and by gradually increasing an impact of the second control law for the second configuration in said flight controller based on an estimated or measured flight condition of the aircraft by dynamically adjusting, in said flight controller, respective maximum and minimum limit values of control volumes that are defined by parameter ranges of control parameters in connection with the corresponding control law for the second configuration.