Fixed-wing aircraft punctual arrival control method under dynamic wind field conditions, electronic device and medium

Abstract

The application discloses a fixed-wing aircraft punctual arrival control method under dynamic wind field conditions, an electronic device and a medium. The method can comprise: calculating the ground-based wind speed of the current position of the aircraft according to sensor information; calculating the relationship between true airspeed and indicated airspeed, the relative relationship of true airspeed and the relative relationship of wind speed at different altitudes; obtaining the relationship of the horizontal ground speed vector, the true airspeed vector and the wind speed vector of each flight segment of the aircraft; constructing a punctual arrival nonlinear equation based on the expected indicated airspeed and solving to obtain the expected indicated airspeed; limiting the expected indicated airspeed as an indicated airspeed command, and controlling the aircraft to fly to the target position. The application can maintain the indicated airspeed and attitude basically stable under the interference of dynamic wind field, so that the aircraft can safely and punctually arrive at the target position.

Description

Technical Field

[0001] This invention relates to the field of aircraft control technology, and more specifically, to a method, electronic equipment, and medium for controlling the timely arrival of a fixed-wing aircraft under dynamic wind field conditions. Background Technology

[0002] Fixed-wing aircraft, with their high speed and long flight time, possess reconnaissance and strike capabilities, and are playing an increasingly important role in modern military affairs. In modern warfare, coordinated operations and precise deployment, ensuring that every step proceeds according to plan, are crucial, which places higher demands on the time management capabilities of aircraft.

[0003] Modern aircraft should have the ability to arrive on time, meaning that given a reasonable target location and expected arrival time, the aircraft can automatically control its flight speed under dynamic wind field interference conditions to ensure that the aircraft arrives at the target location at the expected time.

[0004] Currently, on-time arrival schemes commonly used for fixed-wing aircraft generally fall into two categories: The first automatically generates the optimal route based on the aircraft's current and target positions, considering flight performance, meteorological data, and airspace restrictions, achieving on-time arrival at the route planning level. The second replaces indicated airspeed control with ground speed control, obtaining the desired ground speed from the target position and expected time, and implementing closed-loop ground speed control, while also adding indicated airspeed and attitude protection, achieving on-time arrival at the speed control level. Scheme one addresses the navigation level, but routes are complex and uncertain, making it difficult to obtain detailed meteorological and airspace information in advance, and real-time planned routes are not unique. Option 2, which focuses on control-level implementation, is simple and direct. However, changing the indicated airspeed control to ground speed control carries certain risks. This is because wind fields exist in the air, and when the ground speed is controlled at a constant level, the indicated airspeed often fluctuates within a certain range. In particular, wind speeds at high altitudes are generally higher, which can cause the aircraft's indicated airspeed to fluctuate significantly and easily reach the indicated airspeed and attitude protection boundaries. This is extremely detrimental to the aircraft's flight safety. Furthermore, when the aircraft is at the indicated airspeed and attitude protection boundaries, it will exit ground speed control, resulting in the inability to achieve the goal of arriving on time.

[0005] Therefore, it is necessary to develop a control method, electronic equipment, and medium for the timely arrival of fixed-wing aircraft under dynamic wind field conditions.

[0006] The information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] This invention proposes a control method, electronic equipment, and medium for the timely arrival of fixed-wing aircraft under dynamic wind field conditions. It can maintain a relatively stable indicated airspeed and attitude under dynamic wind field interference, enabling the aircraft to safely and punctually reach its target location. Based on a predetermined flight path, this invention achieves timely arrival at the control level. The flight path is simple and deterministic, reducing detours and waiting time.

[0008] In a first aspect, embodiments of this disclosure provide a method for controlling the timely arrival of a fixed-wing aircraft under dynamic wind field conditions, including:

[0009] The ground wind speed at the aircraft's current location is calculated based on sensor information;

[0010] Calculate the relationship between vacuum velocity and indicated air velocity at different altitudes, the relative relationship between vacuum velocity and wind speed;

[0011] Obtain the relationship between the horizontal ground speed vector, vacuum speed vector, and wind speed vector of the aircraft for each flight segment;

[0012] Construct and solve a nonlinear equation for on-time arrival based on the desired indicated airspeed to obtain the desired indicated airspeed;

[0013] The desired airspeed is limited and then used as the airspeed command to control the aircraft to fly to the target position.

[0014] Preferably, the ground-level wind speed is:

[0015] VW gx =VD gx -VT gx

[0016] VW gy =VD gy -VT gy

[0017] VW gz =VD gz -VT gz

[0018] In the formula, VD gx VD gy VD gz VW is the projection of the ground velocity onto the xyz axes of the ground coordinate system. gx VW gy VW gz This represents the projection of wind speed onto the xyz axes of the ground coordinate system.

[0019] Preferably, the relationship between the vacuum velocity and the indicated space velocity is as follows:

[0020]

[0021] The relative relationship of the vacuum velocity is as follows:

[0022]

[0023] The relative relationship of wind speeds is as follows:

[0024]

[0025] In the formula, VI is the indicated airspeed, ρ0 is the standard air density at sea level, ρ is the actual air density at the current altitude, and ρ h1 VW h1 VI h1 VT h1 These represent the air density, wind speed, indicated airspeed, and vacuum velocity at height h1, respectively. h2 VWh2, VI h2 VT h2 These are the air density, wind speed, indicated airspeed, and vacuum speed at height h2, respectively.

[0026] Preferably, the relationship between the horizontal ground speed vector, the vacuum speed vector, and the wind speed vector is as follows:

[0027]

[0028] In the formula, VT is the vacuum velocity, VD is the ground velocity, and VW is the wind speed. The angle between the ground speed vector and the wind speed vector.

[0029] Preferably, the on-time arrival nonlinear equation based on the desired indicated airspeed is:

[0030]

[0031] In the formula, T is the time difference between the current time and the expected arrival time, and X... i Let VD be the length of the i-th segment. i Let be the ground speed of the aircraft in the i-th segment. Let ρ be the angle between the aircraft's direction and the wind direction in the i-th flight segment. i Let V be the air density of the aircraft in the i-th segment, VW be the wind speed of the aircraft in the i-th segment, ρ be the air density at the current position of the aircraft, and VI be the desired indicated airspeed.

[0032] Preferably, the on-time arrival nonlinear equation based on the desired indicated airspeed is solved using Newton's iterative method:

[0033]

[0034] In the formula, the airspeed indicated by the current iteration point is VI. n The next iteration point indicates the airspeed as VI.n+1 ,f′(VI n ) is f(VI n The derivative of VI with respect to VI n The value at that location.

[0035] Preferably, the stopping condition of the Newton iteration method is any one of the following:

[0036] When the absolute value of the difference between the calculated arrival time and the expected arrival time is less than the required time accuracy;

[0037] The absolute value of the difference between the indicated airspeed calculated in this iteration and the indicated airspeed calculated in the previous iteration is less than the airspeed control accuracy.

[0038] Three consecutive iterations of the calculation indicate that the airspeed has reached the controllable safety limit boundary.

[0039] Preferably, it further includes:

[0040] Safety protection measures are set up during the on-time arrival flight of the aircraft. If a system malfunction is detected or the indicated airspeed / attitude / angle of attack / sideslip angle exceeds the normal range, the on-time arrival strategy will be immediately terminated, and the aircraft will fly at the optimal trim indicated airspeed and send an alarm.

[0041] Secondly, embodiments of this disclosure also provide an electronic device, the electronic device comprising:

[0042] Memory, which stores executable instructions;

[0043] A processor that executes the executable instructions in the memory to implement the timed arrival control method for fixed-wing aircraft under dynamic wind field conditions.

[0044] Thirdly, this disclosure also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the aforementioned method for controlling the timely arrival of a fixed-wing aircraft under dynamic wind field conditions.

[0045] Its beneficial effects are as follows:

[0046] (1) The present invention can calculate the expected indicated airspeed in real time according to the current wind field under dynamic wind field interference conditions, maintain the indicated airspeed to change smoothly, and enable the aircraft to reach the target position safely and on time.

[0047] (2) Based on real-time estimated wind field information, the present invention solves the on-time arrival equation, which can make the arrival time of the aircraft more accurate.

[0048] (3) This invention supports on-time arrival under varying flight segment altitudes. By measuring the air density at the current position of the aircraft and combining it with an international standard atmospheric model, the air density at other flight segment altitudes can be calculated, thereby obtaining the relationship between vacuum speed and indicated airspeed at each flight segment altitude. This method uses the current position of the aircraft as a benchmark for calculation, and the calculation results are more accurate.

[0049] (4) The present invention has high calculation efficiency, strong applicability, and stable changes in indicated airspeed commands, which is beneficial to flight safety.

[0050] The methods and apparatus of the present invention have other features and advantages that will be apparent from or will be set forth in detail in the accompanying drawings and following detailed description, which together serve to explain the particular principles of the invention. Attached Figure Description

[0051] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same parts.

[0052] Figure 1 A flowchart illustrating the steps of a fixed-wing aircraft on-time arrival control method under dynamic wind field conditions according to an embodiment of the present invention is shown.

[0053] Figure 2 A flight path diagram from the current position of an aircraft to the target position is shown according to an embodiment of the present invention. Detailed Implementation

[0054] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0055] Figure 1 A flowchart illustrating the steps of a fixed-wing aircraft on-time arrival control method under dynamic wind field conditions according to an embodiment of the present invention is shown.

[0056] like Figure 1 As shown, the control method for the timely arrival of a fixed-wing aircraft under dynamic wind field conditions includes:

[0057] Step 101: Calculate the ground wind speed at the current location of the aircraft based on sensor information;

[0058] Step 102: Calculate the relationship between vacuum velocity and indicated air velocity, the relative relationship of vacuum velocity, and the relative relationship of wind speed at different altitudes;

[0059] Step 103: Obtain the relationship between the horizontal ground speed vector, vacuum speed vector, and wind speed vector for each flight segment of the aircraft;

[0060] Step 104: Construct and solve the on-time arrival nonlinear equation based on the desired indicated airspeed to obtain the desired indicated airspeed;

[0061] Step 105: The desired indicated airspeed is limited and then used as the indicated airspeed command to control the aircraft to fly to the target position.

[0062] In one example, the ground-based wind speed is:

[0063] VW gx =VD gx -VT gx

[0064] VW gy =VD gy -VT gy

[0065] VW gz =VD gz -VT gz

[0066] In the formula, VD gx VD gy VD gz VW is the projection of the ground velocity onto the xyz axes of the ground coordinate system. gx VW gy VW gz This represents the projection of wind speed onto the xyz axes of the ground coordinate system.

[0067] In one example, the relationship between vacuum velocity and indicated space velocity is as follows:

[0068]

[0069] The relative relationship of vacuum velocities is:

[0070]

[0071] The relative relationship of wind speed is:

[0072]

[0073] In the formula, VI is the indicated airspeed, ρ0 is the standard air density at sea level, ρ is the actual air density at the current altitude, and ρ h1 VW h1 VI h1 VT h1 These represent the air density, wind speed, indicated airspeed, and vacuum velocity at height h1, respectively. h2 VWh2, VIh2 VT h2 These are the air density, wind speed, indicated airspeed, and vacuum speed at height h2, respectively.

[0074] In one example, the relationship between the horizontal ground velocity vector, the vacuum velocity vector, and the wind speed vector is as follows:

[0075]

[0076] In the formula, VT is the vacuum velocity, VD is the ground velocity, and VW is the wind speed. The angle between the ground speed vector and the wind speed vector.

[0077] In one example, the nonlinear equation for on-time arrival based on the desired indicated airspeed is:

[0078]

[0079] In the formula, T is the time difference between the current time and the expected arrival time, and X... i Let VD be the length of the i-th segment. i Let be the ground speed of the aircraft in the i-th segment. Let ρ be the angle between the aircraft's direction and the wind direction in the i-th flight segment. i Let V be the air density of the aircraft in the i-th segment, VW be the wind speed of the aircraft in the i-th segment, ρ be the air density at the current position of the aircraft, and VI be the desired indicated airspeed.

[0080] In one example, the nonlinear equation for timely arrival based on the desired indicated airspeed is solved using Newton's iteration method:

[0081]

[0082] In the formula, the airspeed indicated by the current iteration point is VI. n The next iteration point indicates the airspeed as VI. n+1 ,f′(VI n ) is f(VI n The derivative of VI with respect to VI n The value at that location.

[0083] In one example, the stopping condition for Newton's iteration method is any of the following:

[0084] When the absolute value of the difference between the calculated arrival time and the expected arrival time is less than the required time accuracy;

[0085] The absolute value of the difference between the indicated airspeed calculated in this iteration and the indicated airspeed calculated in the previous iteration is less than the airspeed control accuracy.

[0086] Three consecutive iterations of the calculation indicate that the airspeed has reached the controllable safety limit boundary.

[0087] In one example, it also includes:

[0088] Safety protection measures are set up during the on-time arrival flight of the aircraft. If a system malfunction is detected or the indicated airspeed / attitude / angle of attack / sideslip angle exceeds the normal range, the on-time arrival strategy will be immediately terminated, and the aircraft will fly at the optimal trim indicated airspeed and send an alarm.

[0089] Specifically, step 1: When the aircraft needs to arrive on time, after inputting the target location and expected arrival time, the wind speed and direction at the current location of the aircraft are first calculated based on sensor information (if there is no wind sensor).

[0090] Using the Soviet coordinate system, the projection of the vacuum velocity onto the xyz axes of the body coordinate system is:

[0091] VT bx =VT

[0092] VT by = -VT*tan(α)

[0093] VT bz =VT / cos(α)*tan(β)

[0094] In the formula, VT is the measured value of vacuum velocity, α is the angle of attack, and β is the sideslip angle, which are measured by an air data machine and an airspeed tube.

[0095] Transform the vacuum velocity from the body coordinate system to the ground coordinate system:

[0096]

[0097] In the formula, Let V be the vacuum velocity vector in the body coordinate system. Let V be the vacuum velocity vector in the ground coordinate system. This is the transformation matrix from the body coordinate system to the ground coordinate system.

[0098] In the formula, θ is the pitch angle and γ is the roll angle. The heading angle can be measured by inertial navigation.

[0099] The surface wind speed can be obtained from the surface vacuum speed and the surface ground speed:

[0100] VW gx =VD gx -VT gx

[0101] VW gy =VD gy -VT gy

[0102] VW gz =VD gz -VT gz

[0103] In the formula, VD gx VD gy VD gz The ground velocity is the projection of the ground velocity onto the xyz axes of the ground coordinate system, which can be measured by GNSS or inertial navigation. VW gx VW gy VW gz This is the projection of wind speed onto the xyz axes of the ground coordinate system.

[0104] Step 2: Calculate the relationship between vacuum velocity and indicated air velocity at different altitudes, the relative relationship between vacuum velocities at different altitudes, and the relative relationship between wind speeds at different altitudes.

[0105]

[0106] In the formula, VI is the indicated airspeed, and ρ0 is the standard air density at sea level, usually taken as 1.225 kg / m³. 3 ρ is the actual air density at the current altitude. h1 VW h1 VI h1 VT h1 These represent the air density, wind speed, indicated airspeed, and vacuum velocity at height h1, respectively. h2 VWh2, VI h2 VT h2 These are the air density, wind speed, indicated airspeed, and vacuum speed at height h2, respectively.

[0107] Therefore, by obtaining the air density at each flight segment altitude, we can deduce the relationship between vacuum speed and indicated airspeed at different altitudes for each flight segment, the relative relationship of vacuum speed at different altitudes, and the relative relationship of wind speed at different altitudes. A flight route consists of multiple segments, each formed by connecting the first and last waypoints. The segment altitude is the average of the altitudes of the first and last waypoints of the segment.

[0108] Based on the principle of minimizing error, during aircraft flight, the air density at the current altitude is taken from the measurement by an atmospheric data machine, and the air density at other altitudes can be calculated from the air density at the current altitude. Assuming that the atmospheric layering conforms to the International Standard Atmosphere Model (ISA) and the ideal gas law, the formulas for the relationship between air density at different altitudes can be expressed as follows:

[0109] 1. If both altitudes h1 and h2 are in the troposphere (0–11000 m), then

[0110]

[0111] In the formula, ρ h1 ρ h2 Let h1 and h2 be the air densities at heights h2 and h2, respectively; T0 be the thermodynamic temperature at sea level, taken as 288.15 K; L be taken as 0.0065 K / m (i.e., the temperature decreases by 0.0065 K for every 1 m increase in altitude); and g be the gravitational acceleration at sea level, taken as 9.80665 m / s². 2 M is the molar mass of air, taken as 0.0289644 kg / mol, and R is the universal gas constant, taken as 8.31432 J / (mol*K).

[0112] 2. If both altitudes h1 and h2 are in the stratosphere (11000–20000 m), then

[0113]

[0114] In the formula, T′ is the stratospheric temperature, taken as 216.65K (assuming it is constant).

[0115] 3. If altitude h1 is in the troposphere and altitude h2 is in the stratosphere, then first use the formula for the air density relationship at different altitudes in the troposphere to calculate the air density ρ at altitude h1. h1 The air density ρ′ at the top of the troposphere (11000m) is obtained. Then, using the formula for the relationship between air density at different altitudes in the stratosphere, the air density ρ at altitude h2 is obtained from the air density ρ′ at the tropospheric-stratospheric boundary. h2 .

[0116] 4. If altitude h1 is in the stratosphere and altitude h2 is in the troposphere, then first use the formula for the air density relationship at different altitudes in the stratosphere to determine the air density ρ at altitude h1. h1 The air density ρ′ at the tropospheric-stratospheric boundary is obtained. Then, using the formula relating air density at different tropospheric altitudes, the air density ρ at altitude h2 is calculated from the air density ρ′ at the tropospheric-stratospheric boundary. h2 .

[0117] Step 3: Assuming that the vertical wind and the vertical velocity of the aircraft are relatively small, the relationship between the horizontal ground speed vector, vacuum speed vector and wind speed vector for each flight segment is obtained.

[0118]

[0119] In the formula, VT is the vacuum velocity, VD is the ground velocity, and VW is the wind speed. The angle between the ground speed vector and the wind speed vector is the angle between the ground speed vector and the reference coordinate system is the ground coordinate system.

[0120] The ground speed vector, vacuum speed vector, and wind speed vector form a side-side-angle triangle relationship. The condition for triangle congruence is that the side opposite to the angle is greater than the adjacent side, that is, vacuum speed is greater than wind speed (only this case is considered).

[0121] Solving for:

[0122]

[0123] The valid solution is:

[0124]

[0125] When the vacuum velocity is greater than the wind speed, the radicand Greater than 0.

[0126] Step 4: Based on the target location, expected arrival time, wind speed and direction, and the length, direction and altitude of each flight segment, calculate the indicated airspeed in real time at regular intervals (e.g., 1 second), and limit this indicated airspeed as the aircraft's indicated airspeed command.

[0127]

[0128] In the formula, T is the time difference between the current time and the expected arrival time, and X... i Let VD be the length of the i-th segment. i Let be the ground speed of the aircraft in the i-th segment. Let ρ be the angle between the aircraft's direction and the wind direction in the i-th flight segment. i Let V be the air density of the aircraft in the i-th segment, VW be the wind speed of the aircraft in the i-th segment, ρ be the air density at the current position of the aircraft, and VI be the expected indicated airspeed of the aircraft.

[0129] In the above equation, only VI is an unknown quantity. Theoretically, VI can be obtained by solving the equation. However, the equation is nonlinear and relatively complex (especially when there are many flight segments), making it difficult to obtain an analytical solution. Furthermore, solving complex nonlinear equations in real time places high demands on the performance of the flight control computer. Therefore, a simpler and more real-time solution method is desired.

[0130] Newton's iteration method and the secant method are two commonly used numerical methods for solving nonlinear equations. Newton's iteration method is more suitable for solving the above equations because it only requires one initial iteration point and has a fast convergence speed (second-order convergence).

[0131] The nonlinear equation solved by Newton's iteration method is:

[0132]

[0133] Assume the current iteration point is VI n Then the result of the next iteration will be:

[0134]

[0135] In the formula, f′(VI) n) is f(VI n The derivative of VI with respect to VI n The value at that location, i.e.:

[0136]

[0137] After entering the on-time arrival strategy, the initial iteration point for the first calculation is the aircraft's current desired indicated airspeed. Subsequent initial iteration points are the desired indicated airspeed obtained from the previous calculation. Iteration stops when the absolute value of the difference between the calculated arrival time and the desired arrival time is less than the required time accuracy (e.g., 10 seconds), or the absolute value of the difference between the indicated airspeed calculated in the current iteration and the indicated airspeed calculated in the previous iteration is less than the airspeed control accuracy (e.g., 0.5 m / s), or when the indicated airspeed reaches the control safety limit boundary for three consecutive iterations. This method updates the indicated airspeed command required for on-time arrival at regular intervals (e.g., 1 second), allowing the aircraft to control its indicated airspeed in real time based on the updated command.

[0138] To avoid excessive fluctuations in the expected indicated airspeed at the end of the flight path, real-time indicated airspeed calculation is stopped when the distance to the target position is 1000m, and the expected indicated airspeed calculated at the distance to the target position is used as the flight path to the target position.

[0139] Safety measures are in place during the on-time arrival flight. If a system malfunction is detected or the indicated airspeed / attitude / angle of attack / sideslip angle exceeds the normal range for a certain period of time, the on-time arrival strategy will be immediately discontinued, and the aircraft will fly at the optimal trim indicated airspeed and send an alarm. During the on-time arrival flight, the aircraft can send a "discontinue on-time arrival" command to exit the on-time arrival strategy and immediately fly at the optimal trim indicated airspeed.

[0140] The above methods can enable fixed-wing aircraft to safely and timely reach their target locations under dynamic wind field conditions.

[0141] The present invention also provides an electronic device, comprising: a memory storing executable instructions; and a processor executing the executable instructions in the memory to implement the above-described method for controlling the timely arrival of a fixed-wing aircraft under dynamic wind conditions.

[0142] The present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for controlling the timely arrival of a fixed-wing aircraft under dynamic wind field conditions.

[0143] To facilitate understanding of the solutions and effects of the embodiments of the present invention, three specific application examples are given below. Those skilled in the art should understand that these examples are merely for the purpose of understanding the present invention, and any specific details therein are not intended to limit the present invention in any way.

[0144] Example 1

[0145] In this embodiment, the aircraft's altitude remains constant, and the wind speed and direction change only once at waypoint 2. In practical applications, the ratio of altitude change to real airspeed and indicated airspeed, as well as its impact on wind speed, can be handled according to step 2. The wind speed and direction can also be updated in real time during each iteration of the indicated airspeed calculation. The specific implementation method in this embodiment is as follows:

[0146] After receiving the target location waypoint 4, the expected arrival time of 600 seconds, and the "arrive on time" instruction, the aircraft enters the on-time arrival process.

[0147] Figure 2 A flight path diagram from the current position of an aircraft to the target position is shown according to an embodiment of the present invention.

[0148] Table 1 shows the flight path information from the current position to the target position of the aircraft according to an embodiment of the present invention. The corresponding flight path map from the current position to the target position is shown in Table 1. Figure 2 As shown, waypoint information includes: waypoint number, X coordinate, Y coordinate, Z coordinate, vector direction pointing to the next waypoint, and horizontal distance to the next waypoint. In this embodiment, waypoint 0 is the aircraft's current position. Figure 2 The symbol “○” indicates that waypoint 4 is the point where the target position is reached on time. Figure 2 The diagram is marked with a "★", and 1 to 3 are waypoints. The arrows point in the direction of the aircraft's current speed. The following section will use this route map as an example to explain in detail the on-time arrival control method for the aforementioned fixed-wing aircraft.

[0149] Table 1

[0150]

[0151] Step 1: After inputting the target location and expected arrival time and sending the "arrive on time" command, if the aircraft is not equipped with a wind sensor, the flight control computer will first calculate the wind speed and direction of the aircraft's current position (i.e., waypoint 0) based on the aircraft's inertial navigation, air data machine and pitot tube measurement information in Table 2.

[0152] Table 2

[0153]

[0154] The components of the vacuum velocity at waypoint 0 along the x, y, and z axes of the aircraft coordinate system are:

[0155] VT bx0 =64.5m / s

[0156] VT by0 = -64.5 * 0.017 = 1.1 m / s

[0157] VT bz0 =64.5 / 1*0=0m / s

[0158] Transform the vacuum velocity from the body coordinate system to the ground coordinate system:

[0159]

[0160] The surface wind speed can be obtained from the surface vacuum speed and the surface ground speed:

[0161] VW gx =61.4-61.3=0.1m / s

[0162] VW gy =0-0=0m / s

[0163] VW gz =0 -20.0 = -20.0 m / s

[0164] Wind speed and direction are:

[0165] VW g0 =20.0m / s,

[0166] Step 2: Calculate the ratio of vacuum speed to indicated airspeed and the relative wind speed at each flight segment altitude. Since the altitude is the same for all flight segments, the wind speed is also the same at 20 m / s. The ratio of vacuum speed to indicated airspeed is:

[0167]

[0168] The ratio of the vacuum speed to the indicated airspeed at the current position of the aircraft can also be obtained by directly dividing the vacuum speed measured by the air data machine by the indicated airspeed value. If the flight segment altitude is different, the ratio of vacuum speed to indicated airspeed at other altitudes can be obtained by the air density calculation method in step 2.

[0169] Step 3: Assuming that the vertical wind and the vertical velocity of the aircraft are relatively small, the relationship between the horizontal ground speed vector, vacuum speed vector and wind speed vector for each flight segment is obtained.

[0170]

[0171]

[0172] In the formula, VD i VT i These are the ground speed and vacuum speed of the aircraft on the segment from waypoint i to waypoint i+1, respectively.

[0173] Step 4: Based on the target location, expected arrival time, wind speed and direction, and the length, direction, and altitude of each flight segment, calculate the indicated airspeed in real time at regular intervals (e.g., 1 second). Limit this indicated airspeed and use it as the aircraft's indicated airspeed command. The nonlinear equation for the aircraft's initial calculation of the indicated airspeed is:

[0174]

[0175] In the formula, Let be the angle between the aircraft's direction in segment i and the wind direction. The angles are 89.8°, 149.8°, 209.8°, and 269.8° respectively.

[0176] Furthermore, the above nonlinear equations are solved using the Newton-Raphson iteration method. The iteration stops when the absolute value of the difference between the calculated arrival time and the expected arrival time is less than 10s, or the absolute value of the difference between the indicated airspeed calculated in the current iteration and the indicated airspeed calculated in the previous iteration is less than 0.5m / s, or the indicated airspeed calculated in three consecutive iterations is less than 40m / s or greater than 70m / s.

[0177] The initial indicated airspeed VI0 = 50 m / s. The theoretical flight time to reach the target position at this indicated airspeed is 757.18 s, which is 157.18 s different from the expected arrival time. The absolute value is greater than 10 s, which does not meet the requirements.

[0178] The formula for the first iteration is:

[0179]

[0180] The difference between the calculated indicated airspeed and the calculated indicated airspeed from the previous iteration is 8.12 m / s, with an absolute value greater than 0.5 m / s. The calculated indicated airspeed is between 40 m / s and 70 m / s. The difference between the theoretical arrival time and the expected arrival time at the expected indicated airspeed calculated in this iteration is 27.752 s, with an absolute value greater than 10 s. Therefore, a second iteration will be performed.

[0181]

[0182] The difference between the calculated indicated airspeed and the one calculated in the previous iteration is 2.11 m / s, with an absolute value greater than 0.5 m / s. The calculated indicated airspeed is between 40 m / s and 70 m / s. The difference between the theoretical arrival time and the expected arrival time calculated in this iteration at the expected indicated airspeed is 1.2212 s, with an absolute value less than 10 s, so the iteration stops. The expected indicated airspeed is 60.23 m / s, which will be used as the current indicated airspeed command for the aircraft.

[0183] Repeat steps 1 through 4 every 1 second. When reaching waypoint 2, note the change in wind field, but the calculation method remains the same. When the aircraft reaches waypoint 2 at indicated airspeed of 60.23 m / s (vacuum speed of 77.7 m / s), it takes 301.22 seconds. The expected arrival time from waypoint 2 to the target waypoint 4 is 298.78 seconds.

[0184] The wind speed and direction at waypoint 2 obtained from step 1 are as follows:

[0185] VW g0 =9.75m / s,

[0186] Since the altitude remains constant, the ratio of vacuum speed to indicated airspeed remains unchanged at 1.29 for each flight segment.

[0187] The relationship between the horizontal ground speed vector, vacuum speed vector, and wind speed vector for the remaining flight segment is obtained from step 3:

[0188]

[0189] The expected indicated airspeed for the remaining segment is calculated in step 4. The nonlinear equation for the indicated airspeed at waypoint 2 is:

[0190]

[0191] In the formula, Let be the angle between the aircraft's direction in segment i and the wind direction. The angles are 255.95° and 315.95° respectively.

[0192] The initial indicated airspeed at waypoint 2 is VI0 = 60.23 m / s. The theoretical flight time to reach the target position at this indicated airspeed is 252.25 s, which is -46.53 s different from the expected arrival time. The absolute value is greater than 10 s, which does not meet the requirements.

[0193] The formula for the first iteration is:

[0194]

[0195] The difference between the calculated indicated airspeed and the calculated indicated airspeed from the previous iteration is 11.23 m / s, with an absolute value greater than 0.5 m / s. The calculated indicated airspeed is between 40 m / s and 70 m / s. The difference between the theoretical arrival time and the expected arrival time at the expected indicated airspeed calculated in this iteration is 10.677 s, with an absolute value greater than 10 s. Therefore, a second iteration will be performed.

[0196]

[0197] The difference between the calculated indicated airspeed and the one calculated in the previous iteration is 1.7 m / s, with an absolute value greater than 0.5 m / s. The calculated indicated airspeed is between 40 m / s and 70 m / s. The difference between the theoretical arrival time and the expected arrival time calculated in this iteration at the expected indicated airspeed is 0.38245 s, with an absolute value less than 10 s, so the iteration stops. The expected indicated airspeed is 50.7 m / s, which will be used as the current indicated airspeed command for the aircraft.

[0198] The Newton iteration process for solving the nonlinear equation for the desired indicated airspeed at waypoints 0 and 2 is shown in Table 3.

[0199] Table 3

[0200] project Waypoint 0 2 waypoints Initial indicated airspeed (m / s) 50 60.23 Indicated airspeed (m / s) after the first iteration 58.12 49 Indicated airspeed (m / s) after the second iteration 60.23 50.7 Expected arrival time 600 298.78 Initial theoretical reach time / error (s) 757.18 / 157.18 252.25 / -46.53 Theoretical time / error (s) after the first iteration 627.75 / 27.75 309.46 / 10.68 The theoretical time / error (s) after the second iteration 601.22 / 1.22 299.16 / 0.38

[0201] Safety measures are in place during the on-time arrival flight. If a system malfunction is detected or the indicated airspeed / attitude / angle of attack / sideslip angle exceeds the normal range for a certain period of time, the on-time arrival strategy will be immediately discontinued, and the aircraft will fly at the optimal trim indicated airspeed and send an alarm. During the on-time arrival flight, the aircraft can send a "discontinue on-time arrival" command to exit the on-time arrival strategy and immediately fly at the optimal trim indicated airspeed.

[0202] Example 2

[0203] This disclosure provides an electronic device, comprising: a memory storing executable instructions; and a processor executing the executable instructions in the memory to implement the aforementioned method for controlling the timely arrival of a fixed-wing aircraft under dynamic wind field conditions.

[0204] An electronic device according to an embodiment of the present disclosure includes a memory and a processor.

[0205] This memory is used to store non-transitory computer-readable instructions. Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM) and / or cache memory. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, etc.

[0206] The processor may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. In one embodiment of this disclosure, the processor is used to execute computer-readable instructions stored in the memory.

[0207] Those skilled in the art will understand that, in order to solve the technical problem of how to achieve a good user experience, this embodiment may also include well-known structures such as communication buses and interfaces, and these well-known structures should also be included within the protection scope of this disclosure.

[0208] For a detailed description of this embodiment, please refer to the corresponding descriptions in the foregoing embodiments, which will not be repeated here.

[0209] Example 3

[0210] This disclosure provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the aforementioned method for controlling the timely arrival of a fixed-wing aircraft under dynamic wind field conditions.

[0211] A computer-readable storage medium according to embodiments of the present disclosure stores non-transitory computer-readable instructions. When these non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the methods described in the foregoing embodiments of the present disclosure are performed.

[0212] The aforementioned computer-readable storage media include, but are not limited to: optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., magnetic tape or portable hard drive), media with built-in rewritable non-volatile memory (e.g., memory card), and media with built-in ROM (e.g., ROM cartridge).

[0213] Those skilled in the art should understand that the above description of the embodiments of the present invention is only intended to illustrate the beneficial effects of the embodiments of the present invention, and is not intended to limit the embodiments of the present invention to any of the examples given.

[0214] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for controlling the timely arrival of a fixed-wing aircraft under dynamic wind field conditions, characterized in that, include: The ground wind speed at the aircraft's current location is calculated based on sensor information; Calculate the relationship between vacuum velocity and indicated air velocity at different altitudes, the relative relationship between vacuum velocity and wind speed; Obtain the relationship between the horizontal ground speed vector, vacuum speed vector, and wind speed vector of the aircraft for each flight segment; Construct and solve a nonlinear equation for on-time arrival based on the desired indicated airspeed to obtain the desired indicated airspeed; The desired airspeed is limited and then used as the airspeed command to control the aircraft to fly to the target position.

2. The method for controlling the timely arrival of a fixed-wing aircraft under dynamic wind field conditions according to claim 1, wherein, The ground-level wind speed is: VW gx =CEO gx -VT gx VW gy =CEO gy -VT gy VW gz =CEO gz -VT gz In the formula, VD gx VD gy VD gz VW is the projection of the ground velocity onto the xyz axes of the ground coordinate system. gx VW gy VW gz This represents the projection of wind speed onto the xyz axes of the ground coordinate system.

3. The method for controlling the timely arrival of a fixed-wing aircraft under dynamic wind field conditions according to claim 1, wherein, The relationship between the vacuum velocity and the indicated air velocity is as follows: The relative relationship of the vacuum velocity is as follows: The relative relationship of wind speeds is as follows: In the formula, VI is the indicated airspeed, ρ0 is the standard air density at sea level, ρ is the actual air density at the current altitude, and ρ h1 VW h1 VI h1 VT h1 These represent the air density, wind speed, indicated airspeed, and vacuum velocity at height h1, respectively. h2 VWh2, VI h2 VT h2 These are the air density, wind speed, indicated airspeed, and vacuum speed at height h2, respectively.

4. The method for controlling the timely arrival of a fixed-wing aircraft under dynamic wind field conditions according to claim 1, wherein, The relationship between the horizontal ground velocity vector, the vacuum velocity vector, and the wind speed vector is as follows: In the formula, VT is the magnitude of vacuum speed, VD is the magnitude of ground speed, VW is the magnitude of wind speed, and θ is the angle between the ground speed vector and the wind speed vector.

5. The method for controlling the timely arrival of a fixed-wing aircraft under dynamic wind field conditions according to claim 1, wherein, The on-time arrival nonlinear equation based on the desired indicated airspeed is: In the formula, T is the time difference between the current time and the expected arrival time, and X... i Let VD be the length of the i-th segment. i Let θ be the ground speed of the aircraft in the i-th segment. i Let ρ be the angle between the aircraft's direction and the wind direction in the i-th flight segment. i Let V be the air density of the aircraft in the i-th segment, VW be the wind speed of the aircraft in the i-th segment, ρ be the air density at the current position of the aircraft, and VI be the desired indicated airspeed.

6. The method for controlling the timely arrival of a fixed-wing aircraft under dynamic wind field conditions according to claim 5, wherein, The on-time arrival nonlinear equation based on the desired indicated airspeed is solved using Newton's iterative method: In the formula, the airspeed indicated by the current iteration point is VI. n The next iteration point indicates the airspeed as VI. n+1 ,f′(VI n ) is f(VI n The derivative of VI with respect to VI n The value at that location.

7. The method for controlling the timely arrival of a fixed-wing aircraft under dynamic wind field conditions according to claim 6, wherein, The stopping condition for Newton's iteration method is any one of the following: When the absolute value of the difference between the calculated arrival time and the expected arrival time is less than the required time accuracy; The absolute value of the difference between the indicated airspeed calculated in this iteration and the indicated airspeed calculated in the previous iteration is less than the airspeed control accuracy. Three consecutive iterations of the calculation indicate that the airspeed has reached the controllable safety limit boundary.

8. The method for controlling the timely arrival of a fixed-wing aircraft under dynamic wind field conditions according to claim 1, wherein, Also includes: Safety protection measures are set up during the on-time arrival flight of the aircraft. If a system malfunction is detected or the indicated airspeed / attitude / angle of attack / sideslip angle exceeds the normal range, the on-time arrival strategy will be immediately terminated, and the aircraft will fly at the optimal trim indicated airspeed and send an alarm.

9. An electronic device, characterized in that, The electronic device includes: Memory, which stores executable instructions; A processor that executes the executable instructions in the memory to implement the timed arrival control method for a fixed-wing aircraft under dynamic wind field conditions as described in any one of claims 1-8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method for timely arrival control of a fixed-wing aircraft under dynamic wind field conditions as described in any one of claims 1-8.

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