Patent ID: 11970284
Assignee: TEXTRON INNOVATIONS INC.
Field: Measurement (Instruments)
Classification: CPC B  G | IPC B  G

Claim 0:
1. A method to determine an airspeed of a powered vehicle comprising a flight computer, the method comprising, during flight:
powering an unmanned aircraft with a fixed pitch propeller along a velocity vector by delivering power from an electric motor to the fixed pitch propeller;
obtaining measurements on the unmanned aircraft of a voltage and current supplied to the electric motor, altitude, and air temperature; and
determining an airspeed value of the unmanned aircraft using an advance ratio for the propeller, comprising:
determining power delivered to the propeller using one or more of the measurements;
determining air density using one or more of the measurements;
determining a propeller power coefficient using the power delivered and the air density;
determining the advance ratio for the propeller using the propeller power coefficient;
further comprising, during flight, determining an angle-of-attack (AOA) of the vehicle using the airspeed value; and

adjusting the power delivered to the propeller based on the air speed value.