An airborne calibration method for an airborne celestial navigation device

Abstract

The application discloses an aerial calibration method of an aviation celestial navigation device, combines a flight route in a flight task of an airplane, integrates aerial calibration work of a celestial navigation system into the flight route, and synchronously carries out tracking and positioning work of a star tracker and a navigation processor in the celestial navigation device after the airplane enters a calibration task area; according to a task route plan, the airplane enters each side of a route path once, and the celestial navigation system completes aerial calibration once under the condition that a heading determination meets a requirement; after completing calibration of the last side, a calibration result is output, and the aerial calibration is completed. The application shifts the environment of calibration work of the celestial navigation device from the ground to the top of the clouds in the air, and synchronously carries out the calibration work with a task, avoids important influence of change of the clouds in the air on a calibration success rate, improves the calibration success rate, saves a large amount of input of manpower and material resources, and can be popularized to the fields of spaceflight and navigation, and has a good guiding role for application, popularization and development of the celestial navigation device.

Description

Technical Field

[0001] This invention belongs to the field of aircraft navigation technology, and specifically relates to an aerial calibration method for aviation astronomical navigation equipment. Background Technology

[0002] Celestial navigation systems typically consist of a navigation processor, a celestial tracker, an astronomical compass, a sextant, and other equipment, and are widely used in aerospace rockets, aircraft, and naval vessels. In the field of aircraft, celestial navigation equipment is often combined with inertial navigation and Doppler navigation systems to form a combined navigation system for precise aircraft navigation. Due to limitations in satellite visibility, low-altitude flight is less suitable for celestial navigation as the primary navigation mode, but it is highly applicable to high-altitude missions performed by bombers, transport aircraft, and reconnaissance aircraft over the ocean, polar regions, and deserts. For long-range ballistic missiles, celestial navigation systems can correct initial launch point positions and aiming angle errors, making them particularly suitable for mobile-launched missiles. Celestial navigation systems can not only independently provide heading and position information for the launch vehicle, but also perform real-time correction of positioning errors in inertial navigation systems in the maritime, aviation, and aerospace fields.

[0003] Celestial navigation systems, especially precision information measurement and processing equipment such as celestial trackers and navigation processors, suffer from accumulated positioning errors during long-term use. This can cause drift in the output heading and position information, leading to deviations from the pre-programmed mission route during air and sea operations. Aircraft or long-range ballistic missiles, during long-endurance high-altitude flights, require high navigation accuracy from their onboard celestial navigation systems. Whether operating independently or in combination with an inertial navigation system, the celestial navigation system must ensure high-precision navigation information throughout the flight. Therefore, celestial navigation systems require periodic benchmark calibration after initial installation or long-term use. Calibration is typically conducted on the ground in conjunction with onboard power-on checks. However, celestial trackers are highly weather-dependent, requiring cloud-free conditions and a 360° rotation on the ground to ensure sufficient effective observations for positioning. This process also demands significant ground support resources. When the calibration cycle of celestial navigation equipment conflicts with the timing of aircraft missions or in cloudy or rainy weather, celestial navigation equipment, as an important navigation method for high-altitude missions, cannot provide accurate positioning data, which contradicts the original design intent of aircraft navigation. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide an aerial calibration method for aviation astronomical navigation equipment. Based on experience in ground-based calibration of astronomical navigation equipment, this method avoids the impact of cloud changes on celestial tracking and positioning during ground calibration. It shifts the calibration process from the ground to above the cloud tops, conducting the calibration simultaneously with the mission execution. This avoids the significant impact of cloud changes on the calibration success rate, improving the first-pass yield while saving substantial manpower and resources.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] An airborne calibration method for an aeronautical astronomical navigation device includes the following steps:

[0007] S1. Plan the airborne calibration route in advance and load it onto the aircraft to confirm that it is read normally;

[0008] S2. Before entering the mission area, confirm that the astronomical navigation equipment has passed its self-test;

[0009] S3. The aircraft flies above the cloud tops to avoid the influence of clouds on aerial calibration.

[0010] S4. After the aircraft's heading is aligned with the first side, it can enter the calibration of the first side. The airborne star tracker and airborne astronomical navigation processor in the astronomical navigation equipment will begin airborne star tracking, locking and positioning.

[0011] S5. After the first side is successfully calibrated, the aircraft moves to the second side. Once the heading is consistent with the second side, it can proceed to calibrate the second side and then calibrate each side in turn.

[0012] S6. After the last calibration is successful, the navigation processor of the airborne celestial navigation processor will give the calibration result;

[0013] S7. After determining that the calibration results meet the requirements based on the aircraft's main navigation equipment, write the calibration results into the astronomical navigation equipment to complete the airborne calibration work.

[0014] Furthermore, to ensure that the astronomical navigation equipment meets the requirements for 360° celestial tracking and positioning, the pre-planned aerial calibration route in step S1 must be a closed polygon. More preferably, the pre-planned aerial calibration route is a closed triangle, quadrilateral, or pentagon. The length of each side of the pre-planned aerial calibration route path is related to the aircraft's flight performance and the mission airspace. If the length of a single side is large, a triangle can be planned; if the length of a single side is small, a quadrilateral or pentagon can be planned.

[0015] Furthermore, the aircraft's mission route must be maintained above the cloud top altitude. If changes in the cloud layer affect aerial calibration, calibration work must be suspended immediately.

[0016] Furthermore, during the aerial calibration process, if one side is successfully calibrated, the process moves to the next side; if either side fails to be calibrated, the entire calibration process must be restarted. A failed calibration side cannot be repeated individually.

[0017] Furthermore, after the calibration of the previous side is successful during the in-flight calibration process, the aircraft switches to the next side. The prerequisite for starting the calibration of the next side is that the aircraft's heading and the heading of the next side remain stable and consistent. The in-flight calibration of the next side cannot start synchronously with the aircraft entering the next side.

[0018] Furthermore, the results provided by the air calibration are comprehensively judged by the pilot in conjunction with other navigation methods. Only when the air calibration results meet the requirements can they be written into the celestial navigation equipment.

[0019] This invention combines the ground calibration principle of astronomical navigation equipment. After the aircraft's onboard astronomical navigation equipment has completed its ground power-on self-test and is flying above cloud top altitude, the star tracker searches for and locks onto celestial bodies. Data on the aircraft's position and distance from the celestial body are then accumulated along a pre-planned mission flight path. The celestial body search and positioning, achieved by rotating 360° on the ground, can be realized in the air by planning a closed flight path. Three rotations on the ground correspond to a planned triangular flight path in the air. Combined with the characteristics of aircraft flight, arbitrarily polygonal flight paths can be planned, accumulating raw positioning data for the calibration of the astronomical navigation equipment. The positioning data collected by the star tracker during flight is synchronously transmitted to the navigation processor for processing. After calibration, the aerial calibration results are provided and loaded. This invention's aerial calibration method for astronomical navigation equipment, based on experience gained from ground calibration, combines the novel idea with the development of aerial calibration routes for aircraft flight missions. It is highly practical and has significant promotional value for the calibration of similar navigation products, providing excellent guidance for scientific research and user application scenarios.

[0020] Under the condition that the technology permits, the present invention shifts the calibration of aeronautical astronomical navigation equipment from the ground to the top of the clouds in the air and carries it out simultaneously with the mission. This avoids the significant impact of changes in the clouds on the calibration success rate, improves the first-pass yield of the calibration work, and saves a lot of manpower and material resources.

[0021] In situations where ground calibration cannot be reliably guaranteed, this invention proposes an in-flight calibration method for aviation astronomical navigation equipment. This method cleverly addresses the shortcomings in its application, providing a new approach for aircraft to successfully execute missions and flexibly respond to in-flight anomalies in astronomical navigation equipment. Astronomical navigation equipment has wide applications in aerospace and maritime systems, and this in-flight calibration method can also be extended to related fields, offering a broader prospect for the in-depth development and application of astronomical navigation equipment. Attached Figure Description

[0022] The present invention will now be described in further detail with reference to the accompanying drawings.

[0023] Figure 1 This is the air calibration logic diagram of the aeronautical astronomical navigation device described in this invention.

[0024] Figure 2 This is a schematic diagram of the air calibration structure of the aeronautical astronomical navigation device described in this invention (the flight path is a closed triangle).

[0025] Figure 3 This is a schematic diagram of the air calibration structure of the aeronautical astronomical navigation equipment described in this invention (the flight path is a closed quadrilateral).

[0026] The diagram shows: 1-Airborne astronomical navigation processor, 2-Airborne star tracker, 3-Airborne star. Detailed Implementation

[0027] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings of this specification are merely for illustrative purposes to aid those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Example

[0030] like Figure 1 As shown, this embodiment provides an airborne calibration method for an aviation astronomical navigation device, including the following steps:

[0031] S1. Plan the airborne calibration route in advance and load it into the airborne celestial navigation processor 1 until the airborne celestial navigation processor 1 confirms that the reading is normal; before the aircraft performs the mission, integrate the airborne calibration route requirements into the mission route. The airborne calibration route requirements include three elements:

[0032] 1) The flight path altitude marked in the air is above the cloud top altitude;

[0033] 2) To enable the airborne satellite tracker 2 to complete a 360° search and positioning of the airborne satellite 3, the calibration route is a closed-loop polygon, such as... Figure 2 The triangular shape shown indicates the flight path and Figure 3 The quadrilateral calibration routes shown can all achieve in-flight calibration; the pre-planned in-flight calibration routes are closed triangles, quadrilaterals, or pentagons. The length of each side of the pre-planned in-flight calibration route path is related to the aircraft's flight performance and the mission airspace. When the length of a single side is large, a triangle can be planned (e.g., Figure 2 As shown), when the length of a single side is small, a quadrilateral can be planned (e.g. Figure 3 (as shown) or pentagon;

[0034] 3) After one side is calibrated, the timing for entering the calibration of the next side is when the aircraft's heading is stable and consistent with the heading of the next side. The specific timing can be controlled by the pilot or the conditions can be determined and planned on the flight path.

[0035] After the route planning and loading are completed, it is confirmed that the airborne equipment (airborne astronomical navigation processor 1) reads the route normally, and the aircraft can take off normally.

[0036] S2. Before the aircraft enters the calibration mission area, check again to confirm that the celestial navigation equipment (including the airborne celestial navigation processor 1, the airborne star tracker 2, and the airborne star 3) is in normal self-test condition, and then prompt the pilot to perform the air calibration operation.

[0037] S3. The aircraft should fly above the cloud tops to avoid the influence of clouds on aerial calibration. If changes in the cloud layer affect aerial calibration, calibration work must be stopped immediately.

[0038] S4. After the aircraft's heading is aligned with the first side, it can enter the calibration of the first side. The airborne celestial body tracker 2 and the airborne celestial navigation processor 1 in the celestial navigation equipment begin tracking, locking, and positioning the airborne celestial body 3. After the airborne celestial body tracker 2 locks onto the airborne celestial body 3 and begins positioning, the celestial navigation equipment enters the calibration of the first side. At the same time, the airborne celestial navigation processor 1 collects and processes the observation data from the airborne celestial body tracker 2.

[0039] S5. After successful calibration on the first side, the aircraft transitions to the second side of the mission route. Once the heading is stable with the second side, the airborne satellite tracker 2 and the airborne astronomical navigation processor 1 enter the second calibration side to begin the search and positioning process. This process is repeated for each side until the calibration of the last side is completed. During in-flight calibration, if one side is successfully calibrated, the aircraft moves to the next side. If any side fails to be calibrated, the entire calibration process must be restarted; a failed calibration side cannot be repeated. After successful calibration on the previous side, the aircraft transitions to the next side. The prerequisite for starting calibration on the next side is that the aircraft's heading is stable and consistent with the heading of the next side. In-flight calibration of the next side cannot begin synchronously with the aircraft entering the next side.

[0040] S6. After the final calibration is successful, the navigation processor of the airborne celestial navigation processor 1 provides the calibration result. The result of the airborne calibration is comprehensively judged by the pilot in combination with other navigation methods. Only if the airborne calibration result meets the requirements can it be written into the airborne celestial navigation processor 1 of the celestial navigation equipment.

[0041] S7. After the calibration results are provided by the airborne astronomical navigation processor 1, the calibration results are written into the astronomical navigation equipment after the main navigation equipment of the aircraft determines that the calibration results meet the requirements to complete the airborne calibration work.

[0042] During the in-flight calibration of celestial navigation equipment, if calibration fails on either side, a self-test must be performed again. After passing the test, the pilot, based on the current mission route, determines whether to begin the next in-flight calibration. The calibration process is generally conducted when the aircraft is above the cloud tops. If changes in cloud cover affect the aircraft's tracking and locking of celestial bodies, the in-flight calibration work must be suspended immediately and resumed when the time is right.

[0043] Other aspects of this invention that are not detailed herein are all conventional techniques known to those skilled in the art.

[0044] It should be noted that the terms “comprising,” “including,” or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0045] The scope of protection of this invention is not limited to the technical solutions disclosed in the specific embodiments. Any modifications, equivalent substitutions, improvements, etc., made to the above embodiments based on the technical essence of this invention shall fall within the scope of protection of this invention.

Claims

1. An aerial calibration method for an aeronautical astronomical navigation device, characterized in that, Includes the following steps: S1. Plan the airborne calibration route in advance and load it onto the aircraft to confirm that it is read normally; S2. Before entering the mission area, confirm that the celestial navigation equipment has passed its self-test; S3. The plane is flying high above the clouds; Among them, the aircraft mission route is maintained above the cloud top altitude. If changes in the cloud layer affect the aerial calibration, the calibration work must be stopped at any time. S4. After the aircraft's heading is aligned with the first side, it can enter the calibration of the first side. The airborne star tracker and airborne astronomical navigation processor in the astronomical navigation equipment will begin airborne star tracking, locking and positioning. S5. After the first side is successfully calibrated, the aircraft moves to the second side. Once the heading is consistent with the second side, it can proceed to calibrate the second side and then calibrate each side in turn. During the aerial calibration process, if one side is successfully calibrated, the process moves to the next side. If any side fails to be calibrated, the entire calibration process must be restarted. A failed calibration side cannot be calibrated repeatedly. During the in-flight calibration process, after the calibration of the previous side is successful, the aircraft will switch to the next side. The prerequisite for starting the calibration of the next side is that the aircraft's heading and the heading of the next side remain stable and consistent. The in-flight calibration of the next side cannot start synchronously with the aircraft entering the next side. S6. After the last calibration is successful, the navigation processor provides the calibration result; S7. After determining that the calibration results meet the requirements based on the aircraft's main navigation equipment, write the calibration results into the celestial navigation equipment to complete the airborne calibration work; The results of the air calibration are determined by the pilot in conjunction with other navigation methods. Only if the air calibration results meet the requirements can they be written into the astronomical navigation equipment.

2. The air calibration method for the aeronautical astronomical navigation equipment according to claim 1, characterized in that: The pre-planned aerial calibration route in step S1 is a closed polygon.

3. The air calibration method for the aeronautical astronomical navigation equipment according to claim 2, characterized in that: The pre-planned aerial navigation routes are closed triangles, quadrilaterals, or pentagons.

Images