초록 ▼

A vertical speed indicator uses a substantially rigid hollow closed air chamber; a capillary tube having a reduced inside diameter connected to the chamber for routing atmospheric air from an aircraft static system at a reduced flow rate into the chamber; a differential pressure transducer having tw

A vertical speed indicator uses a substantially rigid hollow closed air chamber; a capillary tube having a reduced inside diameter connected to the chamber for routing atmospheric air from an aircraft static system at a reduced flow rate into the chamber; a differential pressure transducer having two inlet ports; a pneumatic conduit connecting the chamber and one of the ports of the transducer for exposing that port to internal chamber air pressure; a pneumatic conduit connected to the other port for exposing that port to atmospheric pressure occurring within the static system; and electronic processing circuitry connected to the transducer for providing an indication of the vertical speed of the aircraft. The processing circuit first compensates the signal by varying its phase in a leading direction to at least offset any pneumatic induced lag occurring in the inventive VSI, and then amplifies and displays the result on a zero center analog meter or digitizes it for subsequent use by other airborne avionic systems. Alternatively, the compensated signal can be digitally averaged over a pre-defined time period to remove random noise and similar effects. The period of time over which a digital average is produced can be lengthened to eliminate adverse effects of unstable air or thermals occurring during climb out.

대표청구항 ▼

An electronic vertical speed indicator for use in an aircraft comprising: a substantially rigid hollow closed air chamber; means connected to said chamber for routing atmospheric air from an aircraft static system into said chamber and for imparting a pre-defined amount of pneumatic resistance to ai

An electronic vertical speed indicator for use in an aircraft comprising: a substantially rigid hollow closed air chamber; means connected to said chamber for routing atmospheric air from an aircraft static system into said chamber and for imparting a pre-defined amount of pneumatic resistance to air flow occurring between said static system and said chamber; a differential pressure transducer having two inlet ports; first means connected between said chamber and one of said ports of said transducer for exposing said one port to air pressure occurring within said chamber; second means connected to the other one of said ports for exposing said other port to atmospheric pressure occurring within said static system; and means, connected to said transducer and responsive to an electronic signal produced thereby, for providing an indication of vertical speed of said aircraft, wherein said indication providing means comprises: means for amplifying said signal by a pre-defined amount to produce an amplified signal; means, responsive to said amplified signal, for varying the phase thereof in a leading direction so as to produce a compensated signal wherein at least a partial amount of pneumatic induced lag inherent therein is offset; means, responsive to said compensated signal, for digitally averaging the compensated signal over a pre-defined time period so as to produce an averaged signal; means, responsive to said compensated signal, for varying the time period over which said digital average is from 0.05 seconds to 0.3 seconds as said vertical speed varies between 200 feet/minute to 500 feet/minute; and means for displaying said averaged signal as said vertical speed indication.