Flight management system for direct flight of transport plane

Abstract

The invention discloses a flight management system for straight flight of a transport plane, and the system comprises a straight flight path construction module which divides an interception path into an arc segment and a straight line segment to a straight flight target point when constructing the interception path according to a straight flight segment, and calculates a turning radius at the arc segment in combination with a ground speed and a maximum turning gradient. The turning efficiency is improved, and the turning transition path is visually presented in front of the unit. In addition, three kinds of direct flight management including'basic 'direct flight, Abeam direct flight and CRS-IN direct flight are provided, and the diversified direct flight requirements of the unit are met.

Description

Technical Field

[0001] The present invention belongs to a special technology in the field of transport aircraft flight management, and is a method for realizing that an aircraft is diverted to shorten flight time and distance due to special circumstances in order to save time and fuel or because of airspace arrangement requirements. Background Art

[0002] As one of the core systems of the aircraft's avionics system, the flight management system provides integrated navigation, flight plan management, flight guidance, flight performance calculation and other functions based on the navigation database, performance database and multi-navigation sensor information from the departure airport to the destination airport during takeoff, climb, cruise, descent, approach and go-around. It provides high-precision navigation and positioning information for the aircraft, supports full mission profile flight performance calculation and optimization, and achieves high-precision flight guidance. During the aircraft's takeoff, en route flight and approach, direct flight as a method of quickly reaching a designated location is often used by pilots, which can reduce the burden on pilots, improve airport operation efficiency, and save time and fuel.

[0003] Direct flight allows the pilot to select any positioning point as the current destination waypoint. The positioning point can be a waypoint in the flight plan or a waypoint outside the flight plan. If "direct flight" is executed, the waypoint becomes an arrival waypoint, and the flight plan will instruct the aircraft to fly from the current position to the waypoint. If the waypoint is a waypoint in the flight plan, all the waypoints before the waypoint in the flight plan will be deleted from the flight plan, and the waypoints after it will remain unchanged; if the waypoint is a waypoint outside the flight plan, this waypoint will be set as the arrival point of the current flight plan, and the order of other waypoints will remain unchanged and connected after the arrival point. The advantage of the direct flight method is that it can quickly reach the designated waypoint, which is more conducive to the execution of certain special tasks or the rapid arrival allowed by control during civil aviation transportation, improving flight efficiency and thus improving the efficiency of airspace use.

[0004] However, in the existing related technologies, transition arcs are not periodically constructed when executing direct flight, so the direct flight transition path cannot be intuitively displayed to the crew. In addition, the existing related technologies lack Abeam direct flight (orthogonal projection direct flight) and CRS-IN direct flight (direct flight to the target point at a specified angle), and cannot meet the crew's diverse direct flight needs. Summary of the invention

[0005] When a transport aircraft is flying compared to fighter aircraft and general aviation aircraft, etc., the tasks of the transport aircraft pilot are more concentrated on long - term flight management. Therefore, a higher degree of automation in flight management is required, and a relatively stable operating attitude is required. The object of the present invention is to provide a flight management system for direct flight of transport aircraft, which calculates the turning radius by combining the ground speed and the maximum turning bank angle, improves the turning efficiency, and visually presents the turning transition path in front of the crew. In addition, the present invention adds Abeam direct flight and CRS - IN direct flight to meet the diverse direct flight needs of the crew.

[0006] The object of the present invention is achieved by the following technical solutions:

[0007] A flight management system for direct flight of transport aircraft, comprising a direct - flight path construction module. When the direct - flight path construction module constructs an interception path according to the direct - flight segment, the interception path is divided into an arc segment and a straight - line segment to the direct - flight target point. The process of constructing the arc - segment path is carried out according to the following steps:

[0008] (1) Inverse - solve the distance dist1 and azimuth angle az1 from the starting point to the direct - flight target point on the great - circle route; calculate the turning radius R, where g is the acceleration due to gravity and φ is the maximum turning bank angle of the transport aircraft;

[0009]

[0010] (2) Judge. If dist1 < R, then record that the transition segment from the starting - point to the turning - exit - point segment to the turning - exit - point to the direct - flight target - point segment is invalid;

[0011] (3) Let the current track azimuth angle of the aircraft be From the starting point along direction R distance, inverse - solve the longitude and latitude of the center O of the great - circle route;

[0012] (4) Inverse - solve the distance dist r and azimuth angle az from the center O to the direct - flight target point on the great - circle route;

[0013] (5) Calculate the included angle Δaz between the line connecting the center and the direct - flight target point and the line connecting the center and the entry - point;

[0014]

[0015] (6) From the center O along direction dist r cos(Δaz) distance, inverse - solve the longitude and latitude of the turning - exit point on the great - circle route;

[0016] (7) Inverse - solve the azimuth angle az1′ from the center to the starting point on the great - circle route;

[0017] (8) The azimuth from the center of the great circle route to the turning exit point is az2′;

[0018] (9) Calculate the central angle ang ctr ;

[0019] ang ctr =|az2′-az1′|

[0020] (10) Calculate the arc length ell;

[0021] ell=ang ctr R

[0022] (11) Calculate the height H1′ of the turning exit point, where the starting point height is H1 and the direct flight target point height is H2;

[0023]

[0024] H1′=λH2+(1-λ)H1

[0025] (12) The transition segment from the starting point to the turning exit point to the turning exit point to the direct flight target point is valid.

[0026] Furthermore, it also includes a human-computer interaction module and a direct flight planning module;

[0027] The human-computer interaction module provides a direct flight page, which includes a direct flight target point identifier input box, an intercept angle input box, an ABEAM check box, and a Finish button. When the crew enters a direct flight target point identifier or uses the default direct flight target point identifier, does not enter any data for the intercept angle, unchecks the "ABEAM POINT" check box, and clicks "Finish", the flight management system enters the "Basic" direct flight mode;

[0028] In the "basic" direct flight mode, the direct flight planning module directly creates an ARINC-424DF segment between the starting point and the selected flight plan waypoint as a "basic" direct flight segment, and the waypoints between the aircraft and the selected flight plan waypoints will be deleted; the starting point is the aircraft position calculated N seconds later based on the aircraft's current speed and heading;

[0029] In the "Basic" direct flight mode, the direct flight path construction module periodically updates the intercept path based on the aircraft position.

[0030] Further, when the direct flight target point identifier is entered on the direct flight page of the human-computer interaction module or the default direct flight target point identifier is used, no data is entered for the intercept angle, the "Abeam POINT" checkbox is checked, and the flight management system enters the Abeam direct flight mode after clicking the "Finish" button;

[0031] In the Abeam direct flight mode, the direct flight plan module creates an ARINC-424DF segment directly from the starting point to the selected waypoint of the flight plan. The waypoints between the aircraft position and the selected waypoint of the flight plan will be deleted, and the projection of the intermediate waypoints will be inserted as Abeam waypoints into this ARINC-424DF segment to generate an Abeam direct flight segment. The starting point is the aircraft position calculated N seconds later based on the current speed and heading of the aircraft.

[0032] In the Abeam direct flight mode, after constructing the arc segment and the straight line segment to the direct flight target point, the direct flight path construction module projects the intermediate points of the flight plan onto the intercept path, deletes the original waypoints of the flight plan, and updates the intercept path periodically according to the aircraft position.

[0033] Furthermore, when the direct flight target point identifier is entered on the direct flight page of the man-machine interaction module or the default direct flight target point identifier is used, the intercept angle is entered, the "ABEAM POINT" checkbox is unchecked, and the "Complete" button is clicked, the flight management system enters the CRS-IN direct flight mode.

[0034] In the CRS-IN direct flight mode, if the waypoint of the flight plan is used as the direct flight target point, the direct flight plan module creates an ARINC-424CF segment with an attached intercept angle as the CRS-IN direct flight segment. This segment goes directly from the current aircraft position to the selected direct flight target point, and the waypoints between the current aircraft position and the selected waypoint will be deleted. If a waypoint outside the flight plan is used as the direct flight target point, an ARINC-CF segment with an attached intercept angle will be created. This segment goes directly from the current aircraft position to the specified waypoint. After this CF segment, a discontinuous segment will be appended, and the remaining waypoints of the original flight plan will follow this discontinuous segment.

[0035] In the CRS-IN direct flight mode, to construct the intercept path, the direct flight path construction module must meet the following two conditions:

[0036] (1) The aircraft heading must intercept the radial line leading to the direct flight waypoint.

[0037] (2) If the aircraft altitude < FL195, the heading change from the aircraft heading to the CRS-IN direct flight azimuth should be less than 120°. If the aircraft altitude ≥ FL195, it should be less than 70°.

[0038] After constructing the intercept path, retain this intercept path until the intercept path is executed or the cross-track distance (XTK) value between the aircraft position and the intercept path exceeds twice the current required performance navigation (RNP) value.

[0039] Furthermore, the human-computer interaction module provides two entrances to the direct flight page: the "direct flight" shortcut key of the cockpit display and control system and the flight management system display interface menu.

[0040] Furthermore, it also includes a direct flight guidance module;

[0041] In the "basic" direct flight mode, when the horizontal navigation mode is already connected, when the "basic" direct flight operation is performed on the current flight plan, the direct flight guidance module will display the "basic" direct flight interception path periodically updated by the direct flight path construction module to the crew as a temporary flight plan; after the temporary flight plan is executed, the current flight plan is updated with the temporary flight plan, and when the connection conditions are met, the horizontal navigation mode will still be connected;

[0042] When the horizontal navigation mode has been pre-positioned but the horizontal navigation mode does not meet the connection conditions, the direct flight guidance module uses the periodically updated "basic" direct flight interception path as a temporary flight plan; as the aircraft moves, when the horizontal navigation mode meets the connection conditions, the horizontal navigation mode will be connected and the current flight plan will be updated with the temporary flight plan;

[0043] When the horizontal navigation mode is in the disconnected state, when a "basic" direct flight operation is performed on the current flight plan, the direct flight guidance module will display the periodically updated "basic" direct flight intercept path as a temporary flight plan; when the temporary flight plan is executed, the direct flight guidance module will continue to update the current flight plan using the temporary flight plan until the horizontal navigation mode is armed; when the horizontal navigation mode is armed, once the temporary flight plan is executed, the horizontal navigation mode will be connected.

[0044] Furthermore, when the horizontal navigation mode is already engaged, when the Abeam direct flight operation is performed on the current flight plan, the direct flight guidance module generates a temporary flight plan based on the Abeam direct flight interception path for display and periodically updates the interception path until the temporary flight plan is executed; when the temporary flight plan is executed, the direct flight guidance module will update the current flight plan with the temporary flight plan, and when the engagement conditions are met, the horizontal navigation mode will remain engaged;

[0045] When the horizontal navigation mode is armed but the conditions for connection are not met, when the Abeam direct flight operation is performed on the current flight plan, the direct flight guidance module will generate a temporary direct flight path based on the Abeam direct flight interception path for display, and update the temporary direct flight path periodically as the aircraft position changes; when executing the temporary flight plan, the horizontal navigation mode will be turned on, and the current flight plan will be updated with the temporary flight plan;

[0046] When the horizontal navigation mode is in the disconnected state, once the temporary flight plan is executed, the direct flight guidance module will continue to update the current flight plan until the horizontal navigation mode is armed; when the horizontal navigation mode is armed, once the temporary flight plan is executed, the horizontal navigation mode will be connected.

[0047] Furthermore, when the horizontal navigation mode has been armed and the conditions for the horizontal navigation mode engagement are met, when a direct flight operation with CRS-IN is executed on the current flight plan, the direct flight guidance mode will generate a temporary flight plan with a CRS-IN direct flight intercept path and retain the intercept path until the temporary flight plan is executed or the deviation XTK value between the aircraft position and the intercept path exceeds 2 times the current RNP value; when the temporary flight plan is executed and the engagement conditions are met, the horizontal navigation mode function will ensure normal guidance so that the aircraft can cut into the new direct flight segment when necessary, and will ensure guidance based on the remaining part of the lateral trajectory of the new current flight plan;

[0048] When the horizontal navigation mode has been armed and the horizontal navigation mode engagement conditions have not been met, the direct flight guidance module retains the intercept path until the temporary flight plan is executed or the XTK value between the aircraft position and the intercept path exceeds twice the current RNP value; when the horizontal navigation mode engagement conditions are met, the flight crew will start a manual turn to intercept the CRS IN direct flight path until the horizontal navigation mode is engaged;

[0049] When the horizontal navigation mode is in the disconnected state, the direct flight guidance module retains the intercept path until the temporary flight plan is executed or the XTK value between the aircraft position and the intercept path exceeds 2 times the current RNP value; when the temporary flight plan is executed, when the horizontal navigation mode is armed and the connection conditions are met, the horizontal navigation mode mode will be connected; if the horizontal navigation mode connection conditions are not met, the flight crew manually turns to intercept the IN-BND direct flight path;

[0050] If the XTK between the aircraft and the segment intercept path exceeds twice the current RNP value, the direct flight guidance module will automatically delete the temporary flight plan regardless of the state of the horizontal navigation mode to prevent the horizontal navigation mode from being disconnected when executing the temporary flight plan.

[0051] The beneficial effects of the present invention are:

[0052] 1. When the aircraft turns, the flight management system combines factors such as the average ground speed of the aircraft and the turning performance limit of the aircraft, adopts the smallest turning radius, and quickly aligns with the direct flight waypoint, which enables the aircraft to quickly reach the direct flight waypoint, reduces the mission execution time and the flight distance during the mission execution, and improves the efficiency of mission execution.

[0053] 2. Construction of direct flight path As the aircraft moves, the flight management system periodically constructs a "basic" direct temporary flight plan path and presents it to the crew, which is more intuitive, until the crew executes (confirms) this direct flight.

[0054] 3. Abeam direct flight can effectively reduce the flight plan distance while projecting the wind and temperature information of the waypoints between the current position of the aircraft and the direct flight waypoints (these waypoints have been deleted) in the original flight plan to the corresponding Abeam waypoints, thereby deleting the intermediate waypoints while leaving the wind and temperature information corresponding to the original waypoints, so as to retain the useful information of the original waypoints as much as possible.

[0055] 4. CRS-IN direct flight can reach the direct flight waypoint at the specified entry angle by the crew, which is conducive to flying directly to the specified waypoint at a specified angle in accordance with the requirements of control, special missions or some airdrop missions.

[0056] 5. A human-computer interaction interface with convenient operation is designed, which can flexibly select the direct flight mode and adapt to the direct flight needs of various scenarios, greatly reducing the operating load of the crew.

[0057] 6. A direct flight transition path was constructed to provide a path reference for navigation performance evaluation during turns, which is conducive to the realization of the RNP function of transport aircraft; BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 This is a diagram of the "direct flight shortcut" and the direct flight entry menu on the flight control page.

[0059] Figure 2 Direct flight page diagram.

[0060] Figure 3 Schematic diagram of creating a “basic” non-stop flight segment.

[0061] Figure 4 Constructed for a "basic" direct flight path (LNAV engaged).

[0062] Figure 5 This is a dynamic diagram of "basic" direct flight guidance (LNAV armed).

[0063] Figure 6 This is a diagram of the "basic" direct flight guidance dynamics (LNAV is not engaged and not armed).

[0064] Figure 7 Created for Abeam direct flight segments.

[0065] Figure 8 Built for Abeam direct flight paths.

[0066] Fig. 9This is a dynamic diagram of Abeam direct flight guidance (LNAV is turned on).

[0067] Fig.10 This is a dynamic diagram of Abeam direct flight guidance (LNAV arming).

[0068] Fig.11 This is a dynamic diagram of Abeam direct flight guidance (LNAV is not engaged and not armed).

[0069] Fig.12 CRS-IN direct flight segment creation (the destination point is a waypoint in the flight plan).

[0070] Fig.13 CRS-IN direct flight segment creation (waypoint outside the destination flight plan).

[0071] Fig.14 Construct a schematic diagram for the CRS-IN direct flight path.

[0072] Fig.15 It is not possible to construct a schematic diagram for the CRS-IN direct flight path.

[0073] Fig.16 This is a dynamic diagram of CRS-IN direct flight guidance (LNAV is on).

[0074] Fig.17 This is a dynamic diagram of CRS-IN direct flight guidance (LNAV arming).

[0075] Fig.18 Dynamic diagram of CRS-IN direct flight guidance (LNAV is armed, but the crew activates MOD FPLN too late).

[0076] Fig.19 This is a dynamic diagram of CRS-IN direct flight guidance (LNAV is not connected and not armed, and the direct flight path is intercepted after a manual turn).

[0077] Fig. 20 This is a dynamic diagram of CRS-IN direct flight guidance (LNAV is connected to direct flight MOD FPLN activation too late).

[0078] Fig.21 This is a dynamic diagram of CRS-IN direct flight guidance (LNAV armed, direct flight MOD FPLN not activated, XTK exceeds 2 times the RNP value).

[0079] Fig. 22 This is a dynamic diagram of CRS-IN direct flight guidance (LNAV is not engaged and XTK exceeds 2 times the RNP value). DETAILED DESCRIPTION

[0080] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0081] A flight management system for direct flights of transport aircraft shown in this embodiment includes a human-computer interaction module, a direct flight plan module, a direct flight path construction module and a direct flight guidance module. According to the mission of the transport aircraft or the civil aviation route transportation requirements, this embodiment can implement three direct flight modes, including "basic" direct flight, Abeam direct flight and COURSE-IN direct flight (hereinafter referred to as CRS-IN direct flight). "Basic" direct flight is to use the unflown waypoints in the flight plan as the direct flight target points, and delete the intermediate waypoints for direct flight. Abeam direct flight is to use the unflown waypoints in the flight plan as the direct flight target points, and use the projections of the original intermediate waypoints as Abeam points for direct flight. CRS-IN direct flight is a direct flight to the direct flight target point according to the specified interception angle.

[0082] The human-computer interaction module provides two ways to enter the direct flight page: the "direct flight" shortcut key of the cockpit display control system and the flight management system display interface menu. Figure 1 The direct flight page contains the direct flight target point identifier input box, the intercept angle input box, the ABEAM check box and the Finish button, as shown in the figure below. Figure 2 As shown. After the crew enters the direct flight page through the "Direct Flight" shortcut key on the cockpit panel or the flight management display menu, they manually enter the direct flight target point identifier or use the default direct flight target point identifier, do not enter any data for the intercept angle, uncheck the "ABEAM POINT" checkbox, and click the "Finish" button to complete the setting of the "basic" direct flight function. Enter the direct flight target point identifier or use the default direct flight target point identifier, do not enter any data for the intercept angle, check the "Abeam POINT" checkbox, and click the "Finish" button to complete the setting of the Abeam direct flight function. Enter the direct flight target point identifier or use the default direct flight target point identifier, enter the intercept angle, uncheck the "ABEAM POINT" checkbox, and click the "Finish" button to complete the setting of the CRS-IN direct flight function. The human-computer interaction module sends the above parameters to the direct flight plan module of the flight management system.

[0083] In the "basic" direct flight mode, the direct flight plan module realizes the generation of a "basic" direct flight segment by specifying a certain unflown waypoint in the flight plan as the direct flight target point, and at the same time deleting the intermediate waypoints from the current position of the aircraft to the direct flight target point. In the Abeam direct flight mode, it is realized to insert the projection of the original intermediate waypoints on the basis of the "basic" direct flight segment to form an Abeam direct flight segment. In the CRS-IN direct flight mode, when the waypoint in the flight plan is used as the direct flight target point, a CRS-IN direct flight segment flying to the target point is generated at the intercept angle; when the waypoint outside the flight plan is used as the direct flight target point, an ARINC-424CF segment is generated at the intercept angle and inserted into the flight plan to form a CRS-IN direct flight segment.

[0084] The direct flight path building module provides calculation and intercept path building algorithms based on "basic" direct flight, Abeam direct flight and CRS-IN direct flight turn exit points, as well as logic that takes into account the inability to build a transition path in CRS-IN direct flight mode.

[0085] When the direct flight guidance module is used as a horizontal guidance source in the flight management system, when the horizontal guidance (hereinafter referred to as LNAV) is "on" (in this state, the aircraft automatically flies according to the flight plan path under the guidance of the flight management system), LNAV "armed" (in this state, the LNAV button on the flight control panel is in the armed state, and when the connection conditions are met, LNAV will switch to the on state) and LNAV "disconnected" (in this state, the LNAV button on the flight control panel is in the disconnected state, and the aircraft does not fly according to the flight plan), the constructed path is updated periodically as the aircraft position changes. And other logic.

[0086] The direct flight planning module, the direct flight path building module and the direct flight guidance module are explained below according to the direct flight mode.

[0087] 1. “Basic” direct flight mode

[0088] In the "basic" direct flight mode, the direct flight planning module creates an ARINC-424DF segment directly from the turn point to the selected flight plan waypoint as a "basic" direct flight segment, such as Figure 3 In the TP-PIKAS segment shown, the turning point TP is the position of the aircraft N seconds later calculated based on the current speed and heading of the aircraft. N can be set according to the performance of the aircraft. In this embodiment, N is set to 1 as an example. The waypoints (JG081, MLK56) between the aircraft and the set flight plan waypoints will be deleted. Figure 3 Altitude, speed, and time constraints for waypoints are also removed.

[0089] In the "basic" direct flight mode, the direct flight path construction module constructs a "basic" direct flight interception path from the turning point to the direct flight target point based on the "basic" direct flight segments and updates the "basic" direct flight interception path periodically. The interception path consists of an arc segment and a straight line segment to the direct flight target point. The interception path does not start directly from the aircraft position to ensure that there is no "S turn" (or overshoot) when turning to the direct route point, which may cause discomfort to passengers or be unfavorable for mission execution.

[0090] The construction process of the arc segment path is carried out according to the following steps, as Figure 4 shown:

[0091] (1) Inverse solution of the great circle route to obtain the distance dist1 and azimuth angle az1 from the turning point T-P point to the direct flight target point; calculate the turning radius R, where g is the acceleration due to gravity and φ is the maximum turning bank angle of the transport aircraft;

[0092]

[0093] (2) Judge that if dist1 < R, then record that the transition segment from the T-P point to the turning exit point TE-P segment to the segment from the turning exit point TE-P to the direct flight target point is invalid;

[0094] (3) Assume that the current track azimuth angle of the aircraft is From the T-P point along direction R distance, the longitude and latitude of the center O are obtained by the forward solution of the great circle route;

[0095] Note: sign(x) is the sign function. If x > 0, sign(x) > 0; if x = 0, sign(x) = 0; if x < 0, sign(x) < 0.

[0096] (4) Inverse solution of the great circle route to obtain the distance dist r and azimuth angle az from the center O to the direct flight target point;

[0097] (5) Calculate the included angle Δaz between the line connecting the center and the direct flight target point and the line connecting the center and the entry point;

[0098]

[0099] (6) From the center O along direction dist r cos(Δaz) distance, the longitude and latitude of the turning exit point TE-P are obtained by the forward solution of the great circle route;

[0100] (7) Inverse solution of the great circle route to obtain the azimuth angle az1' from the center to the T-P point;

[0101] (8) Inverse solution of the great circle route to obtain the azimuth angle az2' from the center to the turning exit point TE-P;

[0102] (9) Calculate the central angle ang ctr , note the situation when az1′ and az2′ are in different symbol quadrants;

[0103] ang ctr =|az2′-az1′|

[0104] (10) Calculate the arc length ell;

[0105] ell=ang ctr R

[0106] (11) Calculate the turn exit point TE-P altitude H1′, where the TP point altitude is H1 and the direct flight target point altitude is H2;

[0107]

[0108] H1′=λH2+(1-λ)H1

[0109] (12) The transition segment from the TP point to the turning exit point TE-P to the turning exit point TE-P to the direct flight target point is valid.

[0110] (13) As the aircraft moves, the above steps are repeated periodically to update the interception path.

[0111] In the "basic" direct flight mode, when the horizontal navigation mode (LNAV) is turned on, when the "basic" direct flight operation is performed on the current flight plan (ACT FPLN), the direct flight guidance module will display the "basic" direct flight interception path periodically updated by the direct flight path construction module as a temporary flight plan (hereinafter referred to as MOD FPLN) to the crew, such as Figure 4 When MOD FPLN is executed, ACT FPLN is updated with MOD FPLN, and when the engagement condition is met (completed by periodic intercept path construction), LNAV mode will still be engaged, such as Figure 4 As shown in T2.

[0112] When LNAV is armed, if the aircraft deviation is greater than 2.5NM and the aircraft has not intercepted the activated localizer, the LNAV mode does not meet the engagement conditions, and the direct flight guidance module displays the periodically updated "basic" direct flight intercept path as MOD FPLN, such as Figure 5 As the aircraft moves, when the MOD FPLN meets the engagement condition (constructed by periodic interception path), the LNAV mode will be engaged and the ACT FPLN will be updated with the MOD FPLN, such as Figure 5 As shown in T2.

[0113] When executing a "basic" direct flight maneuver on the ACT FPLN while LNAV is disconnected, the direct flight guidance module displays the periodically updated "basic" direct flight intercept path as the MOD FPLN. The direct flight intercept path is as follows: Figure 6 When executing Figure 6 When the MOD FPLN shown in T2 is executed, the direct flight guidance module will continue to update the ACT FPLN using the MOD FPLN until the LNAV mode is armed. When the LNAV mode is armed, once the MOD FPLN is executed, the LNAV mode will be engaged, such as Figure 6 shown.

[0114] (II) Abeam direct flight mode

[0115] In Abeam direct flight mode, the direct flight plan module will create an ARINC-424DF segment directly from the steering angle to the selected flight plan waypoint. The waypoints between the aircraft position and the selected flight plan waypoint will be deleted. Unlike the "basic" direct flight mode, the projection of the intermediate waypoints is inserted as Abeam waypoints into the ARINC-424DF segment to generate an Abeam direct flight segment. Figure 7 As shown in the figure, speed, altitude and time constraints are not transferred from the original intermediate waypoint to the corresponding Abeam waypoint. When the distance between Abeam and the original intermediate waypoint is less than 100 nautical miles, the wind data corresponding to the original intermediate waypoint is transferred to the corresponding Abeam waypoint. The Abeam waypoint identifier is "AB + original waypoint". Figure 7 shown.

[0116] In Abeam direct flight mode, similar to the "basic" direct flight mode, the direct flight path construction module will build an intercept path from the turning point to the direct flight target point. The construction process is as follows Figure 8 As shown, the intercept path consists of an arc segment and a straight line segment to a direct flight waypoint. The starting point of the arc is the turning point TP. The radius is calculated based on the aircraft performance and average ground speed. The straight line is tangent to the arc and ends at the direct flight target point. The Abeam waypoint is the projection of the midpoint of the flight plan on the Abeam direct flight segment, located between the current position of the aircraft and the selected target waypoint. The original flight plan waypoint is deleted. The intercept path construction process is the same as the "basic" direct flight mode. Based on this intercept path, the projection points are calculated to generate Abeam points to form the Abeam direct flight intercept path.

[0117] When the horizontal navigation mode LNAV is engaged, when performing an Abeam direct flight operation on the ACT FPLN, the direct flight guidance module generates a MOD FPLN based on the Abeam direct flight interception path for display, such as Fig. 9The FMS will periodically update this interception path, as shown in T0. Fig. 9 When MOD FPLN is executed, the direct flight guidance module will update the ACT FPLN with the MOD FPLN, and LNAV will remain engaged when the engagement conditions are met, such as Fig. 9 As shown in the T2 moment.

[0118] When LNAV is armed, initially, the LNAV mode is ready, but the aircraft deviation is greater than 2.5 and does not meet the engagement condition and the aircraft has not intercepted the activation segment. When performing Abeam direct flight operation on ACT FPLN, the direct flight guidance module will generate a direct flight temporary path based on the Abeam direct flight interception path for display, such as Fig.10 As shown in T0, the direct flight temporary path is updated periodically as the aircraft position changes, such as Fig.10 When executing MOD FPLN, LNAV mode will be turned on, and ACT FPLN will be updated when MOD FPLN is used, such as Fig.10 As shown in T2 in . The Abeam point is also updated as the intercept path is updated.

[0119] When the horizontal navigation mode is in the off state, once MOD FPLN is executed, the direct flight guidance module will continue to update ACT FPLN until the LNAV mode is armed. When the LNAV mode is armed, once MOD FPLN is executed, the LNAV mode will be engaged, such as Fig.11 As shown in T3.

[0120] (III) CRS-IN direct flight mode

[0121] In CRS-IN direct flight mode, if the flight plan waypoint is used as the direct flight target point, the direct flight plan module creates an ARINC-424CF segment with an intercept angle (i.e., approach angle) as the CRS-IN direct flight segment. This segment goes directly from the aircraft's current position to the selected direct flight target point. The waypoints between the aircraft's current position and the selected waypoint will be deleted. Fig.12 If a waypoint outside the flight plan is used as a direct flight target, the direct flight plan module will create an ARINC-CF segment with an entry angle, which directly flies from the current position of the aircraft to the specified waypoint. After this CF segment, the direct flight plan module will add a discontinuous segment, and the remaining waypoints of the original flight plan will follow the discontinuous segment, as shown in the figure below. Fig.13 shown.

[0122] In the CRS-IN direct flight mode, the direct flight path construction module constructs a CRS-IN direct flight intercept path from the waypoint to the aircraft's heading, using the aircraft's current position as the waypoint (abbreviated as IN-BND) based on the CRS-IN direct flight segment, and retains the CRS-IN direct flight intercept path. This continues until the CRS-IN direct flight intercept path is executed or the cross-track distance (XTK) value between the aircraft's position and the intercept path exceeds twice the current required performance navigation (RNP) value.

[0123] The intercept path consists of an arc segment and a straight line segment to the direct flight waypoint. The construction process of the arc segment is the same as that of "basic" direct flight, as Fig.15 shown. This figure shows that the aircraft's heading does not intercept the intercept angle to the target direct flight waypoint. Therefore, the intercept path cannot be constructed.

[0124] To construct a CRS-IN direct flight intercept path, the following two conditions must be met:

[0125] (1) The aircraft's heading must intercept the radial line leading to the direct flight waypoint (defined by CRS-IN direct flight);

[0126] (2) If the aircraft altitude < FL195, the heading change from the aircraft's heading to the CRS-IN direct flight azimuth should be less than 120°, and if the aircraft altitude ≥ FL195, it should be less than 70°.

[0127] When the horizontal navigation mode is already engaged and a CRS-IN direct flight operation is performed on the ACT FPLN, the direct flight guidance mode generates a MOD FPLN for display based on the CRS-IN direct flight intercept path, as Fig.16 shown in the top figure (T0). The position of the aircraft at time T0 is inserted as a waypoint into the MOD FPLN, called IN-BND, which is defined by the latitude and longitude of the aircraft at time T0. The direct flight guidance mode retains the CRS-IN direct flight intercept path until the MOD FPLN is executed or the cross-track distance (XTK) value between the aircraft's position and the intercept path exceeds twice the current required performance navigation (RNP) value. As Fig.16 shown in the middle figure (T1), the XTK value does not exceed this limit; when the MOD FPLN is executed ( Fig.16 bottom figure (T2)), the LNAV function will perform flight guidance based on the activated MOD FPLN.

[0128] When the horizontal navigation mode is already armed and the LNAV engagement condition is met, and a CRS-IN direct flight operation is performed on the ACT FPLN, the direct flight guidance mode will generate a MOD FPLN with a CRS-IN direct flight intercept path, as Fig.17The aircraft at time T0 is inserted as a MOD FPLN from the waypoint, called IN-BND, with the longitude and latitude of the aircraft at time T0. The FMS retains the intercept path until the MOD FPLN is executed or the deviation XTK value between the aircraft position and the intercept path exceeds 2 times the current RNP value. Fig.17 As shown in the middle figure (T1), the XTK value does not exceed this limit. When executing MOD FPLN ( Fig.17 When the LNAV function is in the following figure (T2) and the connection conditions are met (XTK < 2.5NM), the LNAV function will ensure normal guidance so that the aircraft can enter a new direct flight segment when necessary (such as Fig.18 as shown in the figure below (T2 and more)) and will ensure guidance for the remainder of the lateral trajectory based on the new ACT FPLN.

[0129] When the horizontal navigation mode is armed and the LNAV engagement conditions are not met, the direct flight guidance module retains the intercept path until MOD FPLN is executed or the XTK value between the aircraft position and the intercept path exceeds 2 times the current RNP value. Fig.18 As shown in the second figure (T1 and T2), when executing MOD FPLN ( Fig.18 The 3rd diagram (T3) of the FMS will ensure that the aircraft is properly guided to intercept the CRS IN direct flight path (such as when the LNAV engagement conditions are met). Fig.18 4 (T4 et seq.) and will ensure guidance for the remainder of the new ACT FPLN lateral trajectory.

[0130] When LNAV is disconnected, the direct flight guidance module retains the intercept path until MOD FPLN is executed or the XTK value between the aircraft position and the intercept path exceeds 2 times the current RNP value. Fig.19 As shown in the second figure (T1), XTK does not exceed this limit and when executing MOD FPLN ( Fig.19 In the third figure (T2), when LNAV is armed and the engagement condition is met (XTK < 2.5 NM), the LNAV mode will be engaged, such as Fig.19 If the LNAV engagement conditions are not met (such as Fig.19 The flight crew must initiate a manual turn to intercept the IN-BND direct path. When this occurs, LNAV will engage without re-building the intercept path (the IN-BND intercept path is already the intercept path). The LNAV function will ensure that the CRS IN direct path is followed. Fig.19 (as shown in Figure 5).

[0131] When the lateral navigation mode is engaged, the IN-BND intercept path is established, but the flight crew does not execute the MOD FPLN (see Fig. 20 In this case, the direct guidance module will automatically delete the MOD FPLN to prevent LNAV from disconnecting when executing MOD FPLN.

[0132] When the lateral navigation mode is armed, the CRS IN direct intercept path is established, but the flight crew does not execute MOD FPLN before the aircraft and segment intercept path deviation XTK value exceeds 2 times the current RNP value (see Fig.21 Bottom diagram). In this case, the DIRECT guidance module will automatically delete MOD FPLN. In this case, the lateral active mode is HDG and LNAV is armed.

[0133] With the lateral navigation mode disengaged, the IN-BND intercept path is established, but the flight crew does not execute the MOD FPLN (see Fig. 22 In this case, the direct guidance module will automatically delete the MOD FPLN to match the behavior of the flight management system when using LNAV.

[0134] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the claims attached to the present invention.

Claims

1. A flight management system for direct flights of transport aircraft, comprising a direct flight path building module, characterized in that When the direct flight path construction module constructs the intercept path according to the direct flight segment, the intercept path is divided into an arc segment and a straight line segment to the direct flight target point. The process of constructing the arc segment path is as follows: (1) Inverse solution of the great circle route to obtain the distance dist1 and azimuth angle az1 from the starting point to the direct flight target point; calculate the turning radius R, where g is the acceleration due to gravity and φ is the maximum turning bank angle of the transport aircraft; (2) Judge that if dist1 < R, then record that the transition segment from the starting point to the turning exit point segment to the turning exit point to the direct flight target point segment is invalid; (3) Assume that the current flight path azimuth of the aircraft is From the starting point Direction R is the distance from the great circle route to obtain the longitude and latitude of the center O; (4) The distance from the center O of the great circle route to the direct flight target point is dist r and azimuth az; (5) Calculate the included angle Δaz between the line connecting the center of the circle and the direct flight target point and the line connecting the center of the circle and the inbound point; (6) From the center O along Direction dist r The longitude and latitude of the turning exit point are obtained by using the positive solution of the distance from the great circle route of cos(Δaz); (7) Inverse solution of the great circle route to obtain the azimuth angle az1' from the center of the circle to the starting point; (8) Inverse solution of the great circle route to obtain the azimuth angle az2' from the center of the circle to the turning exit point; (9) Calculate the central angle angct r ; English ctr =|az′ z -az′1| (10) Calculate the arc length ell; ell = the ctr R (11) Calculate the height H1' of the turning exit point, where H1 is the height of the starting point and H2 is the height of the direct flight target point; H′1 = λH2+(1 - λ)H1 (12) Record that the transition segment from the starting point to the turning exit point segment to the turning exit point to the direct flight target point segment is valid.

2. A flight management system for direct transport aircraft according to claim 1, characterized in that It also includes a human-machine interaction module and a direct flight flight plan module; The human-machine interaction module provides a direct flight page. The direct flight page includes an input box for the direct flight target point identifier, an input box for the intercept angle, an ABEAM checkbox, and a complete button. When the crew inputs the direct flight target point identifier or uses the default direct flight target point identifier, does not input any data for the intercept angle, unchecks the "ABEAM POINT” checkbox, and clicks "Complete”, the flight management system enters the "basic” direct flight mode; In the "basic” direct flight mode, the direct flight plan module directly creates an ARINC-424DF segment between the starting point and the selected flight plan waypoint as the "basic” direct flight segment, and the waypoints between the aircraft and the set flight plan waypoint will be deleted; The starting point is the position of the aircraft calculated N seconds later according to the current speed and heading of the aircraft; In the "basic” direct flight mode, the direct flight path construction module updates the intercept path periodically according to the aircraft position.

3. A flight management system for direct transport aircraft according to claim 2, characterized in that When the direct flight target point identifier is input on the direct flight page of the human-machine interaction module or the default direct flight target point identifier is used, no data is input for the intercept angle, the "Abeam POINT” checkbox is checked, and the "Complete” button is clicked, the flight management system enters the Abeam direct flight mode; In the Abeam direct flight mode, the direct flight flight plan module directly creates an ARINC-424DF segment from the starting point to the selected flight plan waypoint. The waypoints between the aircraft position and the selected flight plan waypoint will be deleted, and the projection of the intermediate waypoint will be inserted as the Abeam waypoint into this ARINC-424DF segment to generate the Abeam direct flight segment; The starting point is the position of the aircraft calculated N seconds later according to the current speed and heading of the aircraft; In the Abeam direct flight mode, after constructing the arc segment and the straight line segment to the direct flight target point, the direct flight path construction module also projects the intermediate points of the flight plan onto the intercept path, deletes the original flight plan waypoints, and updates the intercept path periodically according to the aircraft position.

4. A flight management system for direct transport aircraft according to claim 2, characterized in that When the identifier of the direct flight target point is input on the direct flight page of the man-machine interaction module or the default direct flight target point identifier is used, the intercept angle is input, the "ABEAM POINT" checkbox is unchecked, and the "Complete" button is clicked, the flight management system enters the CRS-IN direct flight mode; In the CRS-IN direct flight mode, if the flight plan waypoint is used as the direct flight target point, the direct flight flight plan module creates an ARINC-424CF segment with the intercept angle as the CRS-IN direct flight segment. This segment directly goes from the current aircraft position to the selected direct flight target point, and the waypoints between the current aircraft position and the selected waypoint will be deleted; if a waypoint outside the flight plan is used as the direct flight target point, an ARINC-CF segment with the intercept angle will be created. This segment directly flies from the current aircraft position to the specified waypoint. After this CF segment, a discontinuous segment will be appended, and the remaining waypoints of the original flight plan will follow this discontinuous segment; In the CRS-IN direct flight mode, for the direct flight path construction module to construct the intercept path, the following two conditions must be met: (1) The aircraft heading must intercept the radial line leading to the direct flight waypoint; (2) If the aircraft altitude < FL195, the heading change from the aircraft heading to the CRS-IN direct flight azimuth should be less than 120°. If the aircraft altitude ≥ FL195, it should be less than 70°; After the intercept path is constructed, the intercept path is retained until the intercept path is executed or the cross-track distance (XTK) value between the aircraft position and the intercept path exceeds twice the current required performance navigation (RNP) value.

5. A flight management system for direct transport aircraft according to claim 2, characterized in that The man-machine interaction module provides two entrances to the direct flight page: the "Direct Flight" shortcut key on the cockpit display and control system and the menu on the flight management system display interface.

6. A flight management system for direct transport aircraft according to claim 2, characterized in that It also includes a direct flight guidance module; In the "Basic" direct flight mode, when the horizontal navigation mode is already engaged and the "Basic" direct flight operation is performed on the current flight plan, the direct flight guidance module displays the "Basic" direct flight intercept path updated periodically by the direct flight path construction module to the flight crew as a temporary flight plan; after the temporary flight plan is executed, the current flight plan is updated with the temporary flight plan, and when the engagement conditions are met, the horizontal navigation mode will still be engaged; When the horizontal navigation mode is pre-armed but does not meet the engagement conditions, the direct flight guidance module takes the periodically updated "Basic" direct flight intercept path as a temporary flight plan; as the aircraft position moves and the horizontal navigation mode meets the engagement conditions, the horizontal navigation mode will be engaged, and the current flight plan is updated with the temporary flight plan; When the horizontal navigation mode is disconnected, when a "basic" direct flight operation is performed on the current flight plan, the direct flight guidance module will display the periodically updated "basic" direct flight intercept path as a temporary flight plan; when a temporary flight plan is executed, the direct flight guidance module will continue to update the current flight plan using the temporary flight plan until the horizontal navigation mode is armed; when the horizontal navigation mode is armed, once the temporary flight plan is executed, the horizontal navigation mode will be connected.

7. A flight management system for direct transport aircraft according to claim 3, characterized in that Also includes direct flight guidance module; When the horizontal navigation mode is already engaged, when an Abeam direct flight operation is performed on the current flight plan, the direct flight guidance module generates a temporary flight plan based on the Abeam direct flight interception path for display and periodically updates the interception path until the temporary flight plan is executed; when the temporary flight plan is executed, the direct flight guidance module will update the current flight plan with the temporary flight plan, and when the engagement conditions are met, the horizontal navigation mode will remain engaged; When the horizontal navigation mode is armed but the connection conditions are not met, when the Abeam direct flight operation is executed on the current flight plan, the direct flight guidance module will generate a temporary direct flight path based on the Abeam direct flight interception path for display, and periodically update the temporary direct flight path as the aircraft position changes; When executing a temporary flight plan, the horizontal navigation mode will be turned on and the current flight plan will be updated with the temporary flight plan; When the horizontal navigation mode is in the disconnected state, once the temporary flight plan is executed, the direct flight guidance module will continue to update the current flight plan until the horizontal navigation mode is armed; when the horizontal navigation mode is armed, once the temporary flight plan is executed, the horizontal navigation mode will be connected.

8. A flight management system for direct transport aircraft according to claim 4, characterized in that Also includes direct flight guidance module; When the horizontal navigation mode is armed and the conditions for engaging the horizontal navigation mode are met, when a direct flight operation with CRS-IN is executed on the current flight plan, the direct flight guidance mode will generate a temporary flight plan with a CRS-IN direct flight intercept path and retain the intercept path until the temporary flight plan is executed or the deviation XTK value between the aircraft position and the intercept path exceeds 2 times the current RNP value; when the temporary flight plan is executed and the conditions for engaging the horizontal navigation mode are met, the horizontal navigation mode function will ensure normal guidance so that the aircraft can cut into the new direct flight segment when necessary, and will ensure guidance based on the remaining part of the lateral trajectory of the new current flight plan; When the horizontal navigation mode has been armed and the horizontal navigation mode engagement conditions have not been met, the direct flight guidance module retains the intercept path until the temporary flight plan is executed or the XTK value between the aircraft position and the intercept path exceeds twice the current RNP value; when the horizontal navigation mode engagement conditions are met, the flight crew will start a manual turn to intercept the CRS IN direct flight path until the horizontal navigation mode is engaged; When the horizontal navigation mode is in the disconnected state, the direct flight guidance module retains the intercept path until the temporary flight plan is executed or the XTK value between the aircraft position and the intercept path exceeds 2 times the current RNP value; when the temporary flight plan is executed, when the horizontal navigation mode is armed and the connection conditions are met, the horizontal navigation mode mode will be connected; if the horizontal navigation mode connection conditions are not met, the flight crew manually turns to intercept the IN-BND direct flight path; If the XTK between the aircraft and the segment intercept path exceeds twice the current RNP value, the direct flight guidance module will automatically delete the temporary flight plan regardless of the state of the horizontal navigation mode to prevent the horizontal navigation mode from being disconnected when executing the temporary flight plan.

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