RU187671U1 - Doppler speed and drift meter with a combined radio altimeter with an antenna system stabilized by the antenna - Google Patents

Abstract

The utility model relates to aviation instrumentation, in particular, to unmanned aircraft systems. Achievable technical result is an increase in the accuracy and reliability of determining the altitude and velocity vector of an aircraft with active maneuvering. The problem is solved in that in the Doppler speed and drift meter, combined with a radio altimeter and using ANN to determine the direction of radar rays relative to the Earth's surface, an antenna system on a turntable is additionally used, which adjusts the radar rays to match the horizontal flight of the aircraft. 3 ill.

Description

The utility model relates to aviation instrumentation, in particular to unmanned aerial systems, and can be used on unmanned aerial vehicles of aircraft, helicopter, multi-rotor and combined types.

The closest in technical essence is a method for determining the vector of the earth's velocity and drift angle of the aircraft [1]. According to the prototype, measurements in the DISS channels of DISS are considered consistent, and are allowed for speed calculations if the energy conditions for stable signal separation calculated according to the spatial orientation and flight altitude of the apparatus obtained from the gyro-inertial navigation system and radio altimeter are satisfied for these measurements. The direction of radiation of DISS radar rays with a fixed antenna system changes in space due to maneuvers of the aircraft, and, at certain angles of roll and pitch, the rays can fall at too great an angle to the earth's surface, or even be located above the horizon. For such rays, due to the low level or the complete absence of the reflected signal, as well as the increase in the area of irradiated spots on the earth's surface, the error in measuring the Doppler frequency shift sharply increases. Therefore, measurements from these channels are not valid, and are not allowed for calculating the velocity vector; previous valid measurements are used instead. The validity criteria for measuring Doppler channels are the angle of incidence of the radar beam and the distance to the earth’s surface, which are calculated from the roll and pitch angles measured by the inertial navigation system, as well as from the flight altitude of the aircraft above the earth’s surface, measured by a radio altimeter.

The disadvantage of the described method is that it uses a fixed antenna system relative to the aircraft, due to which the angle of incidence of the radar beam on the earth's surface during maneuvers of the aircraft changes. As a result, the measurement error of the Doppler frequency shift in the Doppler channels changes, and the measurement error of the delay in the altimeter channel also changes. The described method is aimed at combating the consequence of this phenomenon, without eliminating its cause.

The aforementioned drawback of the existing method is proposed to be eliminated by placing the antenna system on a turntable, and controlling the direction of the radar rays by measuring the inertial navigation system. A functional diagram of a Doppler speed and drift meter with a combined radio altimeter with an ANS-stabilized antenna system is shown in FIG. 1, on which are indicated:

1 - Doppler speed and drift meter;

2 - radio altimeter;

3 - inertial navigation system;

4 - antenna system;

5 - turntable.

The principle of operation of the utility model is illustrated in FIG. 2.

The aircraft (1) maneuvers with a roll angle ϕ, which is fixed by an inertial navigation system (3, see Fig. 1), while the radar rays (3), due to the antenna system (2) on a turntable (5, see Fig. . 1), deviate in the opposite direction at the same angle. Thus * the radar rays, in a certain sector of the roll and pitch angles, will have directions that correspond to the horizontal flight of the aircraft.

Achievable technical result is an increase in the accuracy and reliability of determining the altitude and velocity vector of an aircraft with active maneuvering. This result is achievable due to the provision of the energy conditions for the stable separation of the radar signal for a wide range of roll angles and pitch, due to which the measurement error of the Doppler frequency shift does not increase and all the radar channels of the meter are allowed to calculate the velocity vector.

The proposed utility model can be implemented using well-known technologies and devices.

Literature

1. The method of determining the vector of earth's speed and drift angle of the aircraft [Text]: US Pat. 2231757 Ross. Federation: IPC G01C 23/00 / Mamoshin V.R .; applicant and patent holder Mamoshin Vladimir Romanovich. - No. 2231757; declared 04/03/2003; publ. 06/27/2004, Bull. Number 18. - 9 p.: Ill.

Claims (1)

A Doppler speed and drift meter with a combined radio altimeter, in which, according to the spatial orientation of the aircraft from an inertial navigation system, the directions of radar rays in space are determined, and for radar measurements only those rays are fulfilled for which the energy conditions of stable emission of the signal reflected from the earth are satisfied , characterized in that it additionally introduced an antenna system on a turntable, which, according to LA-governmental orientation of the inertial navigation system, the working angle sector, produces radar tuning direction of the rays for their compliance with the aircraft horizontal flight.

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