Omnidirectional airspeed system
First Claim
1. An omnidirectional air speed system comprising a mast, a shaft mounted for rotation within the mast, an arm connected to the shaft and extending radially therefrom for rotating with the shaft, means for rotating the shaft, pressure samplers on opposite ends of the shaft, a pressure differential sensor connected to the pressure samplers for producing a signal related to differential pressure, a disc mounted on the shaft having at least one irregularity and irregularity sensing means mounted adjacent the disc for sensing the irregularity, means connected to the irregularity sensing means and to the pressure differential sensor for producing indications of speed vectors and sums.
3 Assignments
0 Petitions
Accused Products
Abstract
A microprocessor receives sensor signals and produces signals proportional to total, longitudinal and lateral air speed. An omnidirectional air speed sensor uses pressure samplers on a rotating arm to produce a sinusoidal pressure differential signal related to air speed. An interrupter disc rotating with the arm periodically exposes an opto-electric sensor to light to produce a pulse phase reference signal. In one embodiment, the pulse signal operates a first ramp generator to produce an arm RPM signal and operates a second ramp generator in conjunction with the sinusoidal signal to produce an azimuth reference signal. The RPM and azimuth signals are fed to a processor to resolve the air speed into longitudinal and lateral components. In the preferred embodiment, the processor receives the pulse signal and produces a pair of out-of-phase square wave signals which control chopper modulators which demodulate the sinusoidal signal to produce signals proportional to lateral and longitudinal speed.
30 Citations
20 Claims
- 1. An omnidirectional air speed system comprising a mast, a shaft mounted for rotation within the mast, an arm connected to the shaft and extending radially therefrom for rotating with the shaft, means for rotating the shaft, pressure samplers on opposite ends of the shaft, a pressure differential sensor connected to the pressure samplers for producing a signal related to differential pressure, a disc mounted on the shaft having at least one irregularity and irregularity sensing means mounted adjacent the disc for sensing the irregularity, means connected to the irregularity sensing means and to the pressure differential sensor for producing indications of speed vectors and sums.
- 10. An omnidirectional air speed system having rotating hollow arms and a differential pressure sensor at inward ends of the hollow arms and communication means for communicating a sinusoidal signal representative of varying differential pressure between the rotating arms and having a temperature sensor and an ambient pressure sensor, the improvement comprising a phase reference indicating means connected to the arms for producing pulses indicating a predetermined angular position of the arms and an air data processor means connected to the phase reference indicating means, to the sinusoidal wave communicating means and to the temperature and pressure means for producing signals proportional to error data including total air speed, axial air speed and lateral air speed.
Specification