Airspeed prediction filter
AssigneeThe Boeing Company
InventorsAndrew W. Houck, Melville D. W. McIntyre
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Abstract
An air data computer outputs a data stream indicative of measured airspeed of an aircraft, for use in generating a display of airspeed to a pilot. To correct for the inherent processing delay, a correction factor is added to the data stream, so that the display is more closely related to the actual airspeed of the aircraft at the time of the display. The correction factor can be calculated by determining the average rate of change of airspeed during a preceding time interval and multiplying the average rate of change by the processing delay.
Claims9
In a method of displaying the airspeed of an aircraft to a pilot, which method includes:
- measuring the airspeed of the aircraft;
- generating a data stream indicative of measured airspeed;
- and
- using the data stream to control a cockpit display of airspeed, wherein a delay occurs between measurement and cockpit display of the airspeed;
- the improvement which comprises:
- calculating a correction factor indicating a predicted change in the airspeed of the aircraft during the delay;
- combining the correction factor with the data stream of measured airspeed to obtain a signal of the predicted airspeed of the aircraft at the time of the display;
- and
- using the combined signal to display the predicted airspeed to the pilot.
In a method of displaying the airspeed of an aircraft to a pilot, which method includes measuring the airspeed of the aircraft, generating a data stream indicative of measured airspeed, and using the data stream to control a cockpit display of airspeed, wherein a delay occurs between measurement and cockpit display of the airspeed, the improvement which comprises filtering the data stream by a second order infinite input response filter, calculating the rate of change of airspeed as indicated by the filtered data stream over a predetermined interval, multiplying the calculated rate of change by the delay to obtain a prediction of the change in the airspeed of the aircraft between the time of measurement of the airspeed and the cockpit display, combining the predicted change with the data stream of measured airspeed, and using the combined data stream and predicted change to display the predicted airspeed to the pilot.
Dependencies are inferred from the claim text.