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US 10,822,109 B2Granted
Methods and systems for determining airspeed of an aircraft
AssigneeThe Boeing Company
InventorJia Luo
Life of this patent
Estimating the term…
Abstract
Aircraft and methods and systems for determining airspeed of an aircraft. The methods and systems allow for calculation of airspeed in near-ground and on-ground aircraft operation. A GPS altitude and a vertical acceleration of the aircraft are obtained for a current time frame. A geometric altitude for the previous time frame is determined, and the difference between the GPS altitude and geometric altitude are combined with the vertical acceleration to calculate a geometric altitude rate of change. The geometric altitude rate of change is used to calculate a pressure altitude rate of change, which is used to calculate a pressure altitude for the aircraft. A static pressure is calculated from the pressure altitude, and the airspeed is calculated using the static pressure.
Claims24
A method of determining an airspeed of an aircraft, the method comprising:
- obtaining, from a GPS device of the aircraft, a GPS altitude of the aircraft for a current time frame;
- obtaining, from an inertial reference device of the aircraft, a vertical acceleration of the aircraft for the current time frame;
- obtaining a geometric altitude of the aircraft for a previous time frame, the previous time frame occurring prior to the current time frame;
- determining a difference between the GPS altitude and the geometric altitude;
- calculating a geometric altitude rate of change of the aircraft using the vertical acceleration and the difference between the GPS altitude and the geometric altitude;
- calculating a pressure altitude rate of change using the geometric altitude rate of change;
- calculating a pressure altitude for the current time frame from the pressure altitude rate of change;
- calculating a static pressure for the current time frame based on the pressure altitude and a sea level static pressure;
- calculating the airspeed of the aircraft using the static pressure;
- obtaining, from the radio altimeter, a radio-based altitude of the aircraft;
- and
- in response to determining the radio-based altitude is below a pre-determined threshold altitude, calculating the geometric altitude rate of change of the aircraft using the difference between the GPS altitude and the geometric altitude without using the vertical acceleration of the aircraft.
9 more elements
A system for determining an airspeed of an aircraft, the system comprising:
- a GPS device of the aircraft capable of determining a GPS altitude of the aircraft;
- an inertial reference device of the aircraft capable of determining a vertical acceleration of the aircraft;
- a computer system of the aircraft, the computer system including one or more processors operatively connected to the GPS device, the inertial reference device, and
- one or more other devices of the aircraft, a database operatively connected to the one or more processors, and a memory operatively connected to the one or more processors and the database, the memory storing data comprising program code for execution by the one or more processors to perform a method for calculating the airspeed of the aircraft, the method comprising:
- obtaining, from the GPS device, the GPS altitude of the aircraft for a current time frame;
- obtaining, from the inertial reference device, the vertical acceleration of the aircraft for the current time frame;
- obtaining a geometric altitude of the aircraft for a previous time frame, the previous time frame occurring prior to the current time frame;
- determining a difference between the GPS altitude and the geometric altitude;
- calculating a geometric altitude rate of change of the aircraft using the vertical acceleration and the difference between the GPS altitude and the geometric altitude;
- calculating a pressure altitude rate of change using the geometric altitude rate of change;
- calculating a pressure altitude for the current time frame from the pressure altitude rate of change;
- calculating a static pressure for the current time frame based on the pressure altitude and a sea level static pressure;
- calculating the airspeed of the aircraft using the static pressure;
- obtaining, from a radio altimeter, a radio-based altitude of the aircraft;
- and
- in response to determining the radio-based altitude is below a pre-determined threshold altitude, calculating the geometric altitude rate of change of the aircraft using the difference between the GPS altitude and the geometric altitude without using the vertical acceleration of the aircraft.
13 more elements
An aircraft comprising:
- a GPS device capable of determining a GPS altitude of the aircraft;
- an inertial reference device capable of determining a vertical acceleration of the aircraft;
- a computer system, the computer system including one or more processors operatively connected to the GPS device, the inertial reference device, and one or more devices of the aircraft, a database operatively connected to the one or more processors, and a memory operatively connected to the one or more processors and the database, the memory storing data comprising program code for execution by the one or more processors to perform a method for calculating an airspeed of the aircraft, the method comprising:
- obtaining, from the GPS device, the GPS altitude of the aircraft for a current time frame;
- obtaining, from the inertial reference device, the vertical acceleration of the aircraft for the current time frame;
- obtaining a geometric altitude of the aircraft for a previous time frame, the previous time frame occurring prior to the current time frame;
- determining a difference between the GPS altitude and the geometric altitude;
- calculating a geometric altitude rate of change of the aircraft using the vertical acceleration and the difference between the GPS altitude and the geometric altitude;
- calculating a pressure altitude rate of change using the geometric altitude rate of change;
- calculating a pressure altitude for the current time frame from the pressure altitude rate of change;
- calculating a static pressure for the current time frame based on the pressure altitude and a sea level static pressure;
- calculating the airspeed of the aircraft using the static pressure;
- obtaining, from a radio altimeter, a radio-based altitude of the aircraft;
- and
- in response to determining the radio-based altitude is below a pre-determined threshold altitude, calculating the geometric altitude rate of change of the aircraft using the difference between the GPS altitude and the geometric altitude without using the vertical acceleration of the aircraft.
12 more elements
A method of determining an airspeed of an aircraft, the method comprising:
- obtaining, from a GPS device of the aircraft, a GPS altitude of the aircraft for a current time frame;
- obtaining, from an inertial reference device of the aircraft, a vertical acceleration of the aircraft for the current time frame;
- obtaining a geometric altitude of the aircraft for a previous time frame, the previous time frame occurring prior to the current time frame;
- determining a difference between the GPS altitude and the geometric altitude;
- calculating a geometric altitude rate of change of the aircraft using the vertical acceleration and the difference between the GPS altitude and the geometric altitude;
- calculating a pressure altitude rate of change using the geometric altitude rate of change;
- calculating a pressure altitude for the current time frame from the pressure altitude rate of change;
- calculating a static pressure for the current time frame based on the pressure altitude;
- calculating the airspeed of the aircraft using the static pressure
- obtaining, from the radio altimeter, a radio-based altitude of the aircraft;
- and
- in response to determining the radio-based altitude is below a pre-determined threshold altitude, calculating the geometric altitude rate of change of the aircraft using the difference between the GPS altitude and the geometric altitude without using the vertical acceleration of the aircraft.
9 more elements
A method of determining an airspeed of an aircraft, the method comprising:
- obtaining, from a GPS device of the aircraft, a GPS altitude of the aircraft for a current time frame;
- obtaining, from an inertial reference device of the aircraft, a vertical acceleration of the aircraft for the current time frame;
- obtaining a geometric altitude of the aircraft for a previous time frame, the previous time frame occurring prior to the current time frame;
- determining a difference between the GPS altitude and the geometric altitude;
- calculating a geometric altitude rate of change of the aircraft using the vertical acceleration and the difference between the GPS altitude and the geometric altitude;
- calculating a pressure altitude rate of change using the geometric altitude rate of change by:
- obtaining a standard day temperature;
- calculating an ambient temperature
- determining a ratio between the standard day temperature and the ambient temperature;
- and
- combining the ratio between the standard day temperature and the ambient temperature with the geometric altitude rate of change to determine the pressure altitude rate of change;
- calculating a pressure altitude for the current time frame from the pressure altitude rate of change;
- calculating a static pressure for the current time frame based on the pressure altitude;
- and
- calculating the airspeed of the aircraft using the static pressure.
12 more elements
A system for determining an airspeed of an aircraft, the system comprising:
- a GPS device of the aircraft capable of determining a GPS altitude of the aircraft;
- an inertial reference device of the aircraft capable of determining a vertical acceleration of the aircraft;
- a computer system of the aircraft, the computer system including one or more processors operatively connected to the GPS device, the inertial reference device, and
- one or more other devices of the aircraft, a database operatively connected to the one or more processors, and a memory operatively connected to the one or more processors and the database, the memory storing data comprising program code for execution by the one or more processors to perform a method for calculating the airspeed of the aircraft, the method comprising:
- obtaining, from the GPS device, the GPS altitude of the aircraft for a current time frame;
- obtaining, from the inertial reference device, the vertical acceleration of the aircraft for the current time frame;
- obtaining a geometric altitude of the aircraft for a previous time frame, the previous time frame occurring prior to the current time frame;
- determining a difference between the GPS altitude and the geometric altitude;
- calculating a geometric altitude rate of change of the aircraft using the vertical acceleration and the difference between the GPS altitude and the geometric altitude;
- calculating a pressure altitude rate of change using the geometric altitude rate of change;
- calculating a pressure altitude for the current time frame from the pressure altitude rate of change by:
- obtaining a standard day temperature;
- calculating an ambient temperature;
- determining a ratio between the standard day temperature and the ambient combining temperature;
- and
- the ratio between the standard day temperature and the ambient temperature with the geometric altitude rate of change to determine the pressure altitude rate of change;
- calculating a static pressure for the current time frame using the pressure altitude;
- and
- calculating the airspeed of the aircraft using the static pressure.
16 more elements
A system for determining an airspeed of an aircraft, the system comprising:
- a GPS device of the aircraft capable of determining a GPS altitude of the aircraft;
- an inertial reference device of the aircraft capable of determining a vertical acceleration of the aircraft;
- a computer system of the aircraft, the computer system including one or more processors operatively connected to the GPS device, the inertial reference device, and
- one or more other devices of the aircraft, a database operatively connected to the one or more processors, and a memory operatively connected to the one or more processors and the database, the memory storing data comprising program code for execution by the one or more processors to perform a method for calculating the airspeed of the aircraft, the method comprising:
- obtaining, from the GPS device, the GPS altitude of the aircraft for a current time frame;
- obtaining, from the inertial reference device, the vertical acceleration of the aircraft for the current time frame;
- obtaining a geometric altitude of the aircraft for a previous time frame, the previous time frame occurring prior to the current time frame;
- determining a difference between the GPS altitude and the geometric altitude;
- calculating a geometric altitude rate of change of the aircraft using the vertical acceleration and the difference between the GPS altitude and the geometric altitude;
- calculating a pressure altitude rate of change using the geometric altitude rate of change;
- calculating a pressure altitude for the current time frame from the pressure altitude rate of change;
- calculating a static pressure for the current time frame using the pressure altitude;
- calculating the airspeed of the aircraft using the static pressure;
- obtaining, from a radio altimeter of the aircraft, a radio-based altitude of the aircraft;
- and
- in response to determining the radio-based altitude is below a pre-determined threshold altitude, calculating the geometric altitude rate of change of the aircraft using the difference between the GPS altitude and the geometric altitude without using the vertical acceleration of the aircraft.
13 more elements
Dependencies are inferred from the claim text.