Aircraft path turning control method

Abstract

This invention belongs to the field of aircraft control technology, specifically relating to an aircraft trajectory turning control method. It projects the destination point of the current flight segment onto a plane with the aircraft's current coordinates as the origin, obtaining the plane coordinates of the destination point; calculates the roll angle command, controlling the aircraft to fly along the plane route; during flight, it determines whether the aircraft has reached the target destination point based on the angle between the destination point and the origin; it switches the current destination point to the destination point of the next flight segment, looping back to step S1 to begin the next flight segment. This invention unifies long-range and near-field navigation, allowing the use of the same navigation calculation method, which is beneficial for maintaining the solution method. It uses no-fly zones to filter out inaccessible points, improving the reliability of navigation calculation; it uses the angle between the flight segment and the aircraft as the basis for completing the flight segment, greatly simplifying the segment completion judgment process and improving judgment accuracy; this invention has a simple process and high control precision when switching during tangent crossing point periods.

Description

Technical Field

[0001] This invention belongs to the field of aircraft control technology, and specifically relates to an aircraft trajectory turning control method. Background Technology

[0002] Flight tracking control of an aircraft is primarily achieved through its flight control system. Understanding how to adjust the flight control system to enable the aircraft to track a predetermined trajectory more effectively and quickly is crucial for improving overall aircraft performance and advancing the aviation industry.

[0003] Flight path control is a crucial part of aircraft control, and its performance directly affects flight safety and flight quality. An aircraft's flight path is typically composed of multiple segments connected sequentially to form a complete path. In this type of zigzag path tracking, if the switching methods between segments are not clearly defined, the aircraft may exhibit circling behavior when changing course.

[0004] Traditional long-range navigation often uses great circle navigation, which can lead to control errors when switching between long-range and local navigation. Due to unreasonable route settings and waypoint arrival errors caused by weather conditions along the route, aircraft may circle in place when switching routes. Traditional tangential cornering requires several stages, including straight-line navigation, roll angle establishment, circular arc navigation, roll angle leveling, and straight-line navigation. The process is complex and requires high levels of coordination between stages. Summary of the Invention

[0005] Purpose of the invention: To address the problem of stationary turning that easily occurs when turning on traditional flight paths, a control method based on planar navigation is proposed to achieve accurate tracking of the flight path when the aircraft turns.

[0006] Technical Solution: To achieve the above-mentioned objectives, the present invention proposes an aircraft trajectory turning control method, the control method comprising the following steps: Step S1: Project the current flight segment from the origin to the destination onto a plane with the aircraft's current coordinates as the origin, to obtain the plane coordinates of the origin to the destination. Step S2: Calculate the roll angle command and control the aircraft to fly along the horizontal flight path; Step S3: During the flight, determine whether the aircraft has reached the target destination based on the angle between the destination and the origin. Step S4: Switch the current destination to the destination of the next flight segment, loop back to step S1, and start the next flight segment.

[0007] Furthermore, in step S1, the Gauss-Kruger projection method will be used to project the current flight segment from the destination point onto a plane with the aircraft's current coordinates as the origin. The meridian direction of the aircraft's location is the y-axis, and the x-axis is perpendicular to the y-axis and points to the right on the plane.

[0008] Furthermore, in step S2, the roll angle command is calculated using L1 navigation, and the aircraft follows the calculated direction. The aircraft's roll angle controls its horizontal flight path.

[0009] Furthermore, the specific calculation process is as follows: point A is defined as the projected starting point, point B is defined as the projected destination point, and P is the current point of the aircraft; the Y-axis points in the meridian direction of the current position of the aircraft, and the X-axis is perpendicular to the Y-axis and points to the right; point S is the point on the line connecting the starting and destination points that is L1 away from the current position of the aircraft and is located in the direction of the aircraft's movement. = , which is lateral acceleration; The angle between the aircraft's current ground speed and the line connecting point PS; D is the perpendicular distance between the aircraft and the line connecting point S and point P (yaw); L1 is the distance between the aircraft and point S. This is the aircraft's current ground speed vector; This is a correction factor; To give the calculated aircraft a roll angle, For navigation damping ratio; For the navigation control cycle, take the time required for the aircraft to turn 360 degrees horizontally at the given maximum roll angle at its current speed; Calculate the roll angle command using the following formula:

[0010] .

[0011] Furthermore, when using tangent-based bending, the calculated minimum length of L1 is... , =D is the side offset. As long as the actual L1 length used is not less than this value, the angle between the calculated alignment point and the current route will not be greater than 70 degrees.

[0012] Furthermore, in step S3, the determination method is to determine whether the aircraft has reached point B based on whether the projection of the aircraft's current point on flight segment AB is within flight segment AB.

[0013] Furthermore, the angle ∠PxBA between the line connecting the aircraft's current point Px and the end point B of the flight segment and the current route AB is used to determine whether the aircraft has reached point B. If the angle ∠PxBA is greater than 90 degrees, the projection of the aircraft's current point Px is not within the flight segment, and the aircraft has reached point B; otherwise, it has not reached point B.

[0014] Furthermore, in step S4, after determining that the previous flight segment is completed, the system does not enter the arc turning control with a fixed center, but instead completely switches from the arrival point to the next flight segment.

[0015] Furthermore, during the switch, the alignment point is calculated using 70 degrees as the maximum entry angle for the new segment. This alignment point is then used as the target point for the route, and the required turning and rolling angle is calculated accordingly.

[0016] Technical effect: The aircraft trajectory turning control method proposed in this invention adopts a combination of long-range projection navigation and near-field planar navigation, which unifies long-range navigation and near-field navigation, allowing the use of the same navigation calculation method, which is beneficial to the maintenance of the solution method.

[0017] By using no-fly zones to filter out inaccessible points, the reliability of navigation calculations is improved; by using the angle between the flight segment and the aircraft as the basis for the completion of the flight segment, the process of judging the completion of the flight segment is greatly simplified and the accuracy of the judgment is improved; the present invention has a simple process and high control precision when switching between tangent crossing points. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the L1 navigation principle; Figure 2 This is a schematic diagram illustrating the navigation principle for segment switching. Figure 3 This is a schematic diagram illustrating the principle of arrival point determination. Detailed Implementation

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings or specific implementation examples. It should be noted that some (but not all) of the disclosed examples are shown in the drawings. In fact, many different examples can be described, and these examples should not be construed as limited to the examples set forth herein. Rather, these examples are described to better demonstrate the positive effects of the present invention, and all aspects not detailed herein are considered to be well-known or conventional techniques in the art.

[0020] See appendix Figures 1-3 The present invention proposes an aircraft trajectory turning control method, the specific implementation process of which includes the following steps: Step 1: Using the Gauss-Kruger projection method (also called the equal-angle transverse cylindrical projection), the current flight segment is projected from the destination point onto a plane with the aircraft's current coordinates as the origin. The meridian direction of the aircraft's location is the y-axis, and the x-axis is perpendicular to the y-axis and points to the right on the plane.

[0021] Step 2: The aircraft uses L1 navigation to calculate the roll angle command and control the aircraft's flight path;

[0022] ; like Figure 1 As shown, point A is the projected starting point, point B is the projected destination point, and P is the aircraft's current point. The Y-axis points along the meridian of the aircraft's current position, and the X-axis is perpendicular to the Y-axis and points to the right. Point S is a point on the line connecting the starting and destination points, located L1 away from the aircraft's current position, in the aircraft's forward direction. = , which is lateral acceleration; The angle between the aircraft's current ground speed and the line connecting point PS; D is the perpendicular distance between the aircraft and the line connecting point S and point P (yaw); L1 is the distance between the aircraft and point S. This is the aircraft's current ground speed vector; This is a correction factor, typically set to 1; To give the calculated aircraft a roll angle, For navigation damping ratio, if overshoot is not required during the transient process, then take 1; The navigation control cycle is the time required for the aircraft to turn 360 degrees horizontally at the given maximum roll angle while maintaining its current speed.

[0023] The aircraft according to the calculation The aircraft roll angle controls the aircraft's horizontal trajectory. When using tangential cornering, the calculated minimum length of L1 is... , =D represents the lateral offset. As long as the actual L1 length used is not less than this value, the angle between the calculated alignment point and the current route will not exceed 70 degrees. This allows the L1 navigation calculation method to continue after a segment switch without requiring additional circular turning. For example... Figure 2 As shown.

[0024] Step 3: Determine if the aircraft has reached point B by checking if its projection onto flight segment AB lies within segment AB. Use the angle ∠PxBA between the line connecting the aircraft's current point Px and the endpoint B of the segment and the current flight path AB to determine if the aircraft has reached point B. The angle ∠PxBA between the aircraft's current point (P1, P2, P3) and the current flight path AB is as follows: Figure 3 As shown, if ∠PxBA is greater than 90 degrees, then the projection of the aircraft's current point Px is not within the flight segment, indicating that the aircraft has reached point B; otherwise, it means that the aircraft has not reached point B.

[0025] Step 4: If the aircraft has reached point B of the current flight segment, switch the next flight segment to the current flight segment and begin the next flight segment.

[0026] The aircraft trajectory turning control method proposed in the above embodiments of the present invention adopts a combination of long-range projection navigation and near-field planar navigation, unifying long-range navigation and near-field navigation, allowing the use of the same navigation calculation method, which is beneficial for the maintenance of the solution method.

[0027] By using no-fly zones to filter out inaccessible points, the reliability of navigation calculations is improved; by using the angle between the flight segment and the aircraft as the basis for the completion of the flight segment, the process of judging the completion of the flight segment is greatly simplified and the accuracy of the judgment is improved; the present invention has a simple process and high control precision when switching between tangent crossing points.

[0028] The above specific embodiments or examples are only used to explain the technical solutions of the present invention and are not intended to limit the present application. Parts not described in detail are considered to be conventional technical means or common knowledge in the field. It can be understood by those skilled in the art that, based on the design concept of the present application, the technical solutions described in the foregoing embodiments can be adapted or some or all of the technical features can be equivalently replaced. These modifications, equivalent replacements, and adaptive improvements do not depart from the technical essence of the present invention and should all be covered within the protection scope of the present application.

Claims

1. A method for controlling the turning trajectory of an aircraft, characterized in that, The control method includes the following steps: Step S1: Project the current flight segment from the origin to the destination onto a plane with the aircraft's current coordinates as the origin, to obtain the plane coordinates of the origin to the destination. Step S2: Calculate the roll angle command and control the aircraft to fly along the horizontal flight path; Step S3: During the flight, determine whether the aircraft has reached the target destination based on the angle between the destination and the origin. Step S4: Switch the current destination to the destination of the next flight segment, loop back to step S1, and start the next flight segment; In step S2, the roll angle command is calculated using L1 navigation, and the aircraft follows the calculated direction. Aircraft roll angle controls the aircraft's horizontal trajectory; The specific calculation process is as follows: Define point A as the projected starting point, point B as the projected destination point, and P as the current point of the aircraft; the Y-axis points in the meridian direction of the current position of the aircraft, and the X-axis is perpendicular to the Y-axis and points to the right; point S is a point on the line connecting the starting and destination points that is L1 away from the current position of the aircraft and is located in the direction of the aircraft's movement. = , which is lateral acceleration; The angle between the aircraft's current ground speed and the line connecting point PS; D is the perpendicular distance between the aircraft and the line connecting point S and point D; L1 is the distance between the aircraft and point S. This is the aircraft's current ground speed vector; This is a correction factor; To give the calculated aircraft a roll angle, For navigation damping ratio; For the navigation control cycle, take the time required for the aircraft to turn 360 degrees horizontally at the given maximum roll angle at its current speed; Calculate the roll angle command using the following formula: ; When using tangents to navigate bends, the minimum calculated length of L1 is... , =D is the side offset. As long as the actual L1 length used is not less than this value, the angle between the calculated alignment point and the current route will not be greater than 70 degrees.

2. The aircraft trajectory turning control method as described in claim 1, characterized in that, In step S1, the Gauss-Kruger projection method will be used to project the current flight segment from the destination point onto a plane with the aircraft's current coordinates as the origin. The meridian direction of the aircraft's location is the y-axis, and the x-axis is perpendicular to the y-axis and points to the right on the plane.

3. The aircraft trajectory turning control method as described in claim 1, characterized in that, In step S3, the determination method is to determine whether the aircraft has reached point B based on whether the projection of the aircraft's current point on flight segment AB is within flight segment AB.

4. The aircraft trajectory turning control method as described in claim 3, characterized in that, The size of the angle ∠PxBA between the line connecting the aircraft's current point Px and the end point B of the flight segment and the current flight path AB determines whether the aircraft has reached point B. If the included angle ∠PxBA is greater than 90 degrees, then the projection of the aircraft's current point Px is not within the flight segment, indicating that the aircraft has reached point B; otherwise, it has not reached it.

5. The aircraft trajectory turning control method as described in claim 1, characterized in that, In step S4, after determining that the previous flight segment is completed, the system does not enter the circular arc turning control with a fixed center, but instead completely switches from the arrival point to the next flight segment.

6. The aircraft trajectory turning control method as described in claim 1, characterized in that, During the switch, the alignment point is calculated using 70 degrees as the maximum entry angle for the new segment. This alignment point is then used as the target point for the route, and the required turning and roll angle is calculated accordingly.

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