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KR-20260063600-A - APPARATUS AND METHOD FOR ESTIMATING AIRSPEED OF AIR VEHICLE UTILIZING A WIND MODEL

KR20260063600AKR 20260063600 AKR20260063600 AKR 20260063600AKR-20260063600-A

Abstract

The present invention relates to an apparatus and method for estimating the airspeed of an aircraft, and more specifically, to an airspeed estimation method and apparatus comprising: a step of generating a wind model based on reference wind conditions at a provided reference altitude; a step of determining current wind speed information according to the current altitude of the aircraft based on the wind model; and a step of estimating the airspeed based on the determined current wind speed and navigation system information.

Inventors

  • 박장성
  • 김경훈
  • 박상혁
  • 권혁훈

Assignees

  • 엘아이지디펜스앤에어로스페이스 주식회사

Dates

Publication Date
20260507
Application Date
20241030

Claims (20)

  1. A step of generating a wind model based on reference wind conditions at a provided reference altitude; A step of determining current wind speed information according to the current altitude of the aircraft based on the above wind model; and A method for estimating airspeed, comprising the step of estimating airspeed based on the current wind speed and navigation system information determined above.
  2. In Article 1, The above wind model is, An airspeed estimation method that linearly reduces the magnitude of the current wind speed corresponding to the current altitude when the current altitude of the aircraft decreases.
  3. In Article 2, The above-mentioned judgment step is, A method for estimating airspeed, comprising the step of determining the magnitude of the current wind corresponding to the altitude of the current aircraft by substituting the altitude of the current aircraft into the following mathematical formula. mathematical formula , (Here, slope , is the current wind size, is the current altitude of the aircraft, is the standard wind size, represents the reference altitude.)
  4. In Article 1, The above standard wind conditions are, Includes information on wind magnitude and wind direction at the above reference altitude, An airspeed estimation method in which the wind direction at the reference altitude in the above wind model is assumed to remain the same until the end of airspeed estimation.
  5. In Article 1, The above navigation system information is. Includes GPS/INS (Global Positioning System/Inertial Navigation System) combined information, The above GPS/INS combined information is, A method for estimating airspeed, comprising ground speed of an aircraft, angular velocity of an aircraft, acceleration of a guided aircraft, attitude angle of an aircraft, and altitude information of said aircraft.
  6. In Article 5, The step of estimating the above waiting speed is, A method for estimating airspeed, comprising the step of constructing a state matrix and a measurement matrix of a system model based on the current wind speed information determined above and the navigation system information, and estimating the airspeed by applying an Extended Kalman Filter (EKF) based on the state matrix of the system model and the measurement matrix.
  7. In Article 6, The above state matrix is, A method for estimating airspeed, comprising the current wind speed, the angular velocity, and the attitude angle, respectively, as state variables.
  8. In Article 6, The above measurement matrix is, A method for estimating airspeed, comprising an airspeed measurement, the angular velocity, and the attitude angle.
  9. In Article 8, The above standby speed measurement is, A method for estimating airspeed, determined by the sum of the current wind speed determined above and the ground speed.
  10. In Article 6, The above extended Kalman filter is, A method for estimating waiting speed, wherein the above measurement matrix is set to be identical to the matrix obtained by adding a measurement noise matrix to the matrix obtained by multiplying the transformation matrix and the state matrix.
  11. A wind model generation unit that generates a wind model based on reference wind conditions at a provided reference altitude; and An airspeed estimation device comprising an airspeed estimation unit that determines current wind speed information based on the current altitude of an aircraft based on the above wind model, and estimates airspeed based on the determined current wind speed and navigation system information.
  12. In Article 11, The above wind model is, An airspeed estimation device that linearly reduces the magnitude of the current wind corresponding to the current altitude when the current altitude of the aircraft decreases.
  13. In Article 12, The above-mentioned airspeed estimation unit is, An airspeed estimation device that calculates the magnitude of the current wind corresponding to the altitude of the current aircraft by substituting the altitude of the current aircraft into the following mathematical formula. mathematical formula , (Here, slope , is the current wind size, is the current altitude of the aircraft, is the standard wind size, represents the reference altitude.)
  14. In Article 11, The above standard wind conditions are, Includes information on wind magnitude and wind direction at the above reference altitude, The above wind model generation unit is, An airspeed estimation device that assumes the wind direction at the above reference altitude remains the same until the end of airspeed estimation.
  15. In Article 11, The above navigation system information is, Includes GPS/INS (Global Positioning System/Inertial Navigation System) combined information, The above GPS/INS combined information is, An airspeed estimation device comprising ground speed, angular velocity, acceleration, attitude angle, and altitude information of an aircraft.
  16. In Article 15, The above-mentioned airspeed estimation unit is, An airspeed estimation device that constructs a state matrix and a measurement matrix of a system model based on the current wind speed information determined above and the navigation system information, and estimates the airspeed by applying an Extended Kalman Filter (EKF) based on the state matrix of the system model and the measurement matrix.
  17. In Article 16, The above state matrix is, A standby speed estimation device comprising, respectively, the standby speed, the angular velocity, and the attitude angle as state variables.
  18. In Article 16, The above state matrix is, A standby speed estimation device comprising, respectively, the standby speed, the angular velocity, and the attitude angle as state variables.
  19. In Article 16, The above state matrix is, A standby speed estimation device comprising, respectively, the standby speed, the angular velocity, and the attitude angle as state variables.
  20. In Article 16, The above extended Kalman filter is, Waiting speed estimation device, wherein the above measurement matrix is set to be identical to the matrix obtained by adding a measurement noise matrix to the matrix obtained by multiplying the transformation matrix and the above state matrix.

Description

Apparatus and Method for Estimating Airspeed of Air Vehicle Using a Wind Model The present invention relates to an apparatus and method for estimating airspeed using a wind model, and more specifically, to an apparatus and method that uses a wind model instead of aircraft model characteristics to estimate the airspeed of an aircraft. Guidance methods for guided aircraft include Pursuit Guidance (PG), which tracks a target by calculating its expected position, and Proportional Navigation Guidance (PNG), which tracks a target by correcting for relative motion based on the angle of view with the target. Proportional navigation guidance systems are characterized by higher guidance accuracy for moving targets compared to tracking guidance systems. In this case, there are guided weapons or aircraft that require airspeed in the process of calculating the line-of-sight angular velocity of the proportional navigation guidance system. In previous studies, airspeed has been estimated by constructing filters that calculate airspeed using aircraft model characteristics such as aerodynamics and thrust. However, determining the model characteristics of such an aircraft requires numerous experiments, such as CFD (Computational Fluid Dynamics), wind tunnel tests, and flight tests, to acquire its aerodynamics, which presents the problem of incurring significant costs. For example, if the model characteristics of an aircraft are identified through a nonlinear filter, a large amount of computation is required to determine those characteristic values. On the other hand, when using a model that linearizes the characteristics of the aircraft model, the amount of computation is lower compared to using a non-linear filter, but the estimation error is larger than that of the non-linear filter, and the operational range of altitude and speed may be limited. The matters described above as background technology are intended only to enhance understanding of the background of the present invention and should not be construed as an acknowledgment that they constitute prior art already known to those skilled in the art. FIG. 1 is a drawing showing an airspeed estimation device according to one embodiment of the present invention. FIG. 2 is a drawing for explaining a wind model according to one embodiment of the present invention. FIG. 3 is a diagram illustrating the estimation process of an estimation device for estimating latency according to one embodiment of the present invention. Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Identical or similar components regardless of drawing symbols are given the same reference number, and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably solely for the ease of drafting the specification, and do not inherently possess distinct meanings or roles. In addition, when describing the embodiments disclosed in this specification, if it is determined that a detailed description of related prior art may obscure the essence of the embodiments disclosed in this specification, such detailed description is omitted. Furthermore, the attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and the technical concept disclosed in this specification is not limited by the attached drawings; it should be understood that the drawings include all modifications, equivalents, and substitutions that fall within the spirit and technical scope of the invention. Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. A singular expression includes a plural expression unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not excluding in advance the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. Before proceeding with the explanation, in this specification, "target aircraft" may refer to a tracking target aircraft according to one embodiment of the presen