Method for constructing navigation performance path required by flight management system to execute point turning

Abstract

The invention discloses a method for constructing a navigation performance path required by a flight management system for executing point turning, and the flight management system aims at the flight plan condition of the point turning. Four transition path construction methods of point turning including initial point turning, continuous point turning, bypass-considered point turning and bypass-prohibited point turning and bypass detection processing are provided, so that the problem that the precision, the reliability, the repeatability and the predictability of point turning performed for a waypoint by a traditional method cannot be ensured is solved; the continuous and smooth reference track can be provided for a pilot, flight guidance and / or flight guidance, continuous and smooth required navigation performance monitoring can be provided for the pilot, the reliability, repeatability and predictability of the flight path of an aircraft are enhanced, and the flight safety in a specified airspace is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aviation, and particularly to a method for constructing a required navigation performance path for a flight management system (FMS) to perform a point turn, to support the FMS in constructing, guiding and displaying a transition path when performing a point turn. The method can provide a continuous and smooth reference track and required navigation performance (RNP) monitoring for the pilot, and enhance the reliability, repeatability and predictability of the aircraft flight path, and improve the safety of flight in a designated airspace. BACKGROUND

[0002] A point turn refers to a circular arc turn in advance according to a predetermined turn slope and ground speed before the aircraft flies to a target waypoint, and the turn ends when the aircraft reaches the airspace above the target waypoint. The aircraft sometimes uses a point turn to intercept the departure heading of the point in advance, so that the aircraft can track the next leg along the departure heading of the point in advance.

[0003] Although the instrument procedure does not contain a point turn operation, the aircraft transitions from a controlled airspace to an uncontrolled airspace, or performs a continuous point turn in an uncontrolled airspace, and the aviation authorities and aircraft manufacturers still hope to use a performance-based method to perform these operations, so that stakeholders can perform on-board performance monitoring and warning on the accuracy, integrity, continuity and availability of regional navigation systems, for example, in the context of accelerating the application of performance-based navigation (PBN) technology in ICAO member states in accordance with the relevant requirements of ICAO and regional implementation plans, the FAA emphasizes the expectation of promoting the implementation of PBN in the “Integration of Powered-Lift: Pilot Certification and Operations; Miscellaneous Amendments Related to Rotorcraft and Airplanes” issued for electric vertical take-off and landing aircraft (eVTOL).

[0004] This means that during the aforementioned operational procedures, the FMS should have the capability to construct an RNP path and complete guidance and display for the flight plan that includes the above operations and PBN procedures. The FMS's RNP path refers to the path calculated by the FMS according to ARINC 702A-5, which has the following characteristics:

[0005] "Establish continuous paths between flight segments... in order to operate within RNP airspace."

[0006] "Based on the aircraft's current status provided by the navigation function and the stored reference path... intercept and track the reference path displayed on the Navigation Display (ND)."

[0007] “Construct an interception path...to enable smooth path interception without excessive rolling or turning in the wrong direction.”

[0008] Therefore, the RNP path construction method for waypoint turns performed by FMS should ensure that the aircraft can still meet airborne performance requirements while executing flight plans that include the above operations, and that stakeholders can monitor airborne performance, thereby improving operational safety. Currently, the waypoint turn operations performed by relevant manufacturers in the aviation technology field cannot meet the above-mentioned performance and functional requirements. Summary of the Invention

[0009] The purpose of this invention is to provide a method for constructing the required navigation performance path for a flight management system to perform a point turn. This method includes transition path construction methods for initial point turns, continuous point turns, point turns considering bypasses, and point turns prohibiting bypasses, as well as bypass detection and processing methods for the above four types of point turns. According to this invention, when a pilot performs a point turn, the FMS can provide the pilot, flight director, and / or flight guide with a high-precision and continuous smooth reference track.

[0010] The objective of this invention is achieved through the following technical solution:

[0011] A method for constructing the required navigation performance path for a flight management system to perform a point turn includes the following steps:

[0012] Step 1, if the current flight segment L to and the next leg L to+j If it exists, proceed to step 2; otherwise, end.

[0013] Step 2: If the current segment index to = 1 and the next segment index j = 1, proceed to step 3; otherwise, proceed to step 7.

[0014] Step 3, if L to Perform a turn at the target point, then proceed to step 4, then proceed to step 6;

[0015] Step 4: Calculate the initial turning point and detect bypass;

[0016] Step 5: If a bypass exists, proceed to step 14; otherwise, proceed to step 16.

[0017] Step 6, calculate other turns;

[0018] Step 7: If j = 1, proceed to step 8; otherwise, proceed to step 11.

[0019] Step 8, if L to If the turn is initiated, proceed to step 9; otherwise, proceed to step 6.

[0020] Step 9: Calculate continuous point turns and detect bypasses;

[0021] Step 10, proceed to step 5;

[0022] Step 11, if L to+j If the turn is initiated, proceed to step 12; otherwise, proceed to step 6.

[0023] Step 12, calculate the turning point considering bypass and detect bypass;

[0024] Step 13, proceed to step 5;

[0025] Step 14, if segment L to+j-1 If bypass is allowed at the destination, increment j and then execute step 1; otherwise, execute step 15.

[0026] Step 15, calculate the turning points where bypassing is prohibited;

[0027] Step 16: Let to = to + j, j = 1, and then execute step 1.

[0028] The beneficial effects of this invention are as follows:

[0029] The present invention fully considers the accuracy, continuity, and smoothness of the reference path when performing a point turn using a performance-based approach, as expected by aviation authorities and aircraft manufacturers, and solves the problem that the flight management system cannot guarantee accuracy, reliability, repeatability, and predictability when performing a point turn using traditional methods. With the popularization and application of the flight management system in various types of aircraft, the flight management system will be equipped on more and more types of aircraft, undertaking path construction, guidance, and display tasks with higher requirements. The present invention can be applied to scenarios where aircraft meeting China Civil Aviation Regulation (CCAR) Part 23 / 25 use the flight management system to perform a point turn, so as to improve the compatibility of the point turn operation and PBN procedures, enhance the reliability, repeatability, and predictability of the flight path of the aircraft, and at the same time provide a continuous and smooth reference track for pilots, flight guidance, and / or flight navigation, as well as support the provision of continuous and smooth RNP monitoring for pilots, thereby enhancing the safety of the aircraft flying in the designated airspace and having broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic flow diagram of a required navigation performance path construction method for a flight management system to perform a point turn.

[0031] Figure 2 It is a schematic diagram of an initial point turn calculated by the FMS. It should be noted that for clear representation, the track in this figure is magnified. In reality, r e should appear much larger than other parameters representing distances.

[0032] Figure 3 It is a schematic diagram of a continuous point turn calculated by the FMS.

[0033] Figure 4 For the FMS calculation Figure 3 It is a schematic diagram of the parameters involved in d1 in the calculation. It should be noted that for clear representation, the track in this figure is magnified. In reality, r e should appear much larger than other parameters representing distances.

[0034] Figure 5 For Figure 4 It is a schematic diagram of the angular error mentioned in the calculation process.

[0035] Figure 6 It is a schematic diagram of a point turn considering bypass calculated by the FMS when d1 > r.

[0036] Figure 7 It is a schematic diagram of a point turn considering bypass calculated by the FMS when d1 < r. It should be noted that for clear representation, the track in this figure is magnified. In reality, r eIt should appear to be much larger than other parameters representing distance.

[0037] Figure 8 A schematic diagram of FMS calculation considering bypass turning points when d1 = r.

[0038] Figure 9 A schematic diagram of a turning point where bypass is prohibited for FMS calculation. Detailed Implementation

[0039] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0040] See Figure 1 As shown in this embodiment, a method for constructing the required navigation performance path for a flight management system to perform a point turn includes transition path construction methods for four types of point turns: initial point turn, continuous point turn, point turn considering bypass, and point turn prohibiting bypass, as well as bypass detection and processing methods for the above four types of point turns. Specifically, it includes the following steps:

[0041] Step 1, if the current flight segment L to and the next leg L to+j If it exists, FMS proceeds to step 2; otherwise, the process ends.

[0042] Step 2: If the current segment index to = 1 and the next segment index j = 1, FMS executes step 3; otherwise, it executes step 7.

[0043] Step 3, if L to If a turn is initiated, FMS proceeds to step 4; otherwise, it proceeds to step 6.

[0044] Step 4, FMS calculates the initial directional turning and detects bypass:

[0045] Step 4.1, refer to Figure 2 FMS initializes the position vector p i (i = 1, 2, 3):

[0046]

[0047] Where, λ to,from For L to From the longitude of the point, l to,from For L to From the point latitude, λ to,to For L to Longitude at point, l to,to For L to Latitude of the point, λ to+j,to For the next leg L to+j From the longitude of the point, l to+j,to For L to+j From point latitude;

[0048] Step 4.2, FMS calculates the unit vector q i (i = 1, 2):

[0049]

[0050] Step 4.3, FMS calculates the symbol turning direction dir:

[0051]

[0052] Where ε is the set minimum value, q i,x (i = 1, 2) (x = 1, 2) are vectors q i The x-th value of (i = 1, 2);

[0053] Step 4.4, FMS calculates the turning radius r:

[0054]

[0055] Among them, v g φ is the ground speed for turning at a specified direction point, φ is the roll angle for turning at a specified direction point, and g is the acceleration due to gravity.

[0056] Step 4.5, if L to >r, FMS indicates that bypass is needed, then proceed to step 5; otherwise, proceed to steps 4 and 6.

[0057] Step 4.6, FMS calculates the turning center p of the turning point. c :

[0058]

[0059] Here, PBD refers to an algorithm that calculates the target position and angle of entry based on a given Place Bearing Distance (PBD). There are various ways to implement this algorithm, which are beyond the scope of this paper. χ out,to+j For L to+j The departure angle;

[0060] Step 4.7, FMS calculates the turning center to L from the turning point. to Distance d from point r And azimuth angle χ:

[0061] (χ,~,d r ) = PBD -1 (p c p1)

[0062] Among them, PBD -1This refers to the inverse solution algorithm of the PBD algorithm. There are multiple ways to implement this algorithm, which are not within the scope of this article.

[0063] Step 4.8, if d r >r, FMS indicates that bypass is required, then proceed to step 5; otherwise, proceed to step 4.9.

[0064] Step 4.9, FMS calculates L to The line connecting point A to the center of the turn and L to The angle Δχ between the lines connecting point A to the turning point A:

[0065]

[0066] Where, r e The radius of the Earth;

[0067] Step 4.10, FMS calculates the turning point p. turn :

[0068]

[0069] Step 5: If a bypass exists, FMS executes step 14; otherwise, it executes step 16.

[0070] Step 6: FMS calculates other turns, which are not within the scope of this article.

[0071] Step 7: If j = 1, FMS executes step 8; otherwise, it executes step 11.

[0072] Step 8, if L to If a turn is initiated, FMS proceeds to step 9; otherwise, it proceeds to step 6.

[0073] Step 9, FMS calculates continuous point turns and detects bypasses:

[0074] Step 9.1, refer to Figure 3 FMS initializes the position vector p i (i = 1, 2, 3):

[0075]

[0076] Step 9.2, FMS calculates the unit vector q i (i = 1, 2):

[0077]

[0078] Step 9.3, FMS calculates the symbol turning direction dir:

[0079] Step 9.4, FMS calculates the turning radius r:

[0080]

[0081] Step 9.5, FMS calculates the turning center p at the target point. c,1 :

[0082]

[0083] Step 9.6, FMS calculates the initial turning center to L. to Projected distance d1:

[0084] Step 9.6.1, refer to Figure 4 FMS initialization p 1b =p1, χ out,1b→(c,1)p =χ out,to , where χ out,to For L to The departure angle;

[0085] Step 9.6.2, FMS calculates from p 1b to p c,1 distance d 1b→(c,1) Departure angle χ out,1b→(c,1) and angle of entry χ in,1b→(c,1) :

[0086] (χ out,1b→(c,1) ,χ in,1b→(c,1) ,d 1b→(c,1) ) = PBD -1 (p 1b ,p c,1 )

[0087] Step 9.6.3, FMS calculates from χ out,1b→(c,1)p To χ out,1b→(c,1) azimuth change

[0088]

[0089] Step 9.6.4, if d 1b→(c,1) ≤ε, FMS let d1=d 1b→(c,1) Then proceed to step 9.7; otherwise, proceed to step 9.6.5.

[0090] Step 9.6.5, if FMS executes step 9.6.6; otherwise, it executes step 9.6.12.

[0091] Step 9.6.6, FMS command

[0092] Step 9.6.7, FMS calculates from p1b to p c,1 In L to Upper projection point p (c,1)p distance d 1b→(c,1)p :

[0093]

[0094] Step 9.6.8, if d 1b→(c,1)p <ε, FMS lets d1 = d 1b→(c,1) Then proceed to step 9.7; otherwise, proceed to step 9.6.9.

[0095] Step 9.6.9, FMS calculates a temporary position vector p tmp :

[0096] p tmp =PBD(p 1b ,χ out,1b→(c,1)p +π, 1.1×d 1b→(c,1)p )

[0097] Step 9.6.10, FMS updates χ out,1b→(c,1)p :

[0098] (χ out,1b→(c,1)p ,~,~)=PBD -1 (p tmp ,p 1b )

[0099] Step 9.6.11, FMS sets p 1b =p tmp ;

[0100] Step 9.6.12, FMS updates d using steps 9.6.2 to 9.6.7. 1b→(c,1)p ;

[0101] Step 9.6.13, FMS initializes p (c,1)p =PBD(p 1b ,χ out,1b→(c,1)p ,d 1b→(c,1)p );

[0102] Step 9.6.14, FMS calculates from p (c,1)p to p 1b angle of entry χ out,(c,1)p→1b :

[0103] (χ out,(c,1)p→1b ,~,~)=PBD -1 (p (c,1)p ,p 1b )

[0104] Step 9.6.15, FMS calculates from p(c,1)p to p c,1 departure angle χ out,(c,1)p→(c,1) and d1:

[0105] (χ out,(c,1)p→(c,1) ,~,d1)=PBD -1 (p (c,1)p ,p c,1 )

[0106] Step 9.6.16, FMS calculates from χ out,(c,1)p→1b To χ out,(c,1)p→(c,1) azimuth change

[0107]

[0108] Step 9.6.17, refer to Figure 5 FMS calculates the angular error e1:

[0109]

[0110] Step 9.6.18, FMS commands d 1b→(c,1)p,1 =d 1b→(c,1)p ;

[0111] Step 9.6.19, FMS calculates p considering e1. 1b to p (c,1)p distance d 1b→(c,1)p,2 :

[0112] d 1b→(c,1)p,2 =d 1b→(c,1)p,1 +e1×d1

[0113] Step 9.6.20, FMS updates p (c,1)p :

[0114] p (c,1)p =PBD(p 1b ,χ out,1b→(c,1)p ,d 1b→(c,1)p,2 )

[0115] Step 9.6.21, FMS updates χ out,(c,1)p→1b :

[0116] (χ out,(c,1)p→1b ,~,~)=PBD -1 (p (c,1)p ,p 1b )

[0117] Step 9.6.22, FMS updates χ out,(c,1)p→(c,1) :

[0118] (χ out,(c,1)p→(c,1) ,~,~)=PBD -1 (p(c,1)p ,p c,1 )

[0119] Step 9.6.23, FMS calculates the new angular error e2:

[0120]

[0121] Step 9.6.24, FMS initializes k = 1;

[0122] Step 9.6.25, if k = 1, or |d 1b→(c,1)p,2 -d 1b→(c,1)p,1 |>ε and k max , where I max If the maximum number of iterations is reached, FMS executes step 9.6.26; otherwise, it executes step 9.7.

[0123] Step 9.6.26, FMS update d 1b→(c,1)p :

[0124]

[0125] Step 9.6.27, FMS updates p (c,1)p :

[0126] p (c,1)p =PBD(p 1b ,χ out,1b→(c,1)p ,d 1b→(c,1)p )

[0127] Step 9.6.28, FMS updates χ out,(c,1)p→1b :

[0128] (χ out,(c,1)p→1b ,~,~)=PBD -1 (p (c,1)p ,p 1b )

[0129] Step 9.6.29, FMS updates d1 and χ out,(c,1)p→(c,1) :

[0130] (χ out,(c,1)p→(c,1) ,~,d1)=PBD -1 (p (c,1)p ,p c,1 )

[0131] Step 9.6.30, FMS sets k = k + 1, d 1b→(c,1)p,1 =d 1b→(c,1)p,2 e1 = e2, d 1b→(c,1)p,2 =d 1b→(c,1)p , Then proceed to step 9.6.25;

[0132] ​Step 9.7, FMS calculates the line connecting the starting turn and the turning center at the point of reference, and L. to The included angle ∠1:

[0133]

[0134] Step 9.8, FMS calculates p turn,2 :

[0135] p turn,2 =PBD(p c,1 ,χ in,to +π-dir×∠1,r)

[0136] Where, χ in,to For L to angle of entry;

[0137] Step 9.9, FMS calculates the initial turning center p c,2 :

[0138] p c,2 =PBD(p turn,2 ,χ in,to +π-dir×∠1,r)

[0139] Step 9.10, FMS calculates the initial turn entry point p. turn,1 :

[0140]

[0141] Step 9.11, FMS calculates p1 and p turn,1 The distance d of the line 1→(turn,1) :

[0142] (~,~,d 1→(turn,1) ) = PBD -1 (p1,p turn,1 )

[0143] Step 9.12, FMS calculates a temporary position vector p tmp :

[0144] p tmp =PBD(p1,χ) out,to ,d 1→(turn,1) )

[0145] Step 9.13, if ||p tmp -p turn,1 If ||≤ε, FMS executes step 9.14; otherwise, it executes step 9.15.

[0146] Step 9.14, if d 1→(turn,1) -d toIf ε >, FMS executes step 9.15; otherwise, it executes step 10, where d to For L to Length;

[0147] In step 9.15, FMS indicates that bypass is required, and then proceeds to step 10;

[0148] Step 10, FMS executes step 5;

[0149] Step 11, if L to+j If a turn is initiated, FMS proceeds to step 12; otherwise, it proceeds to step 6.

[0150] Step 12, FMS calculates the directional turning points and detects bypasses:

[0151] Step 12.1, refer to Figure 6 , Figure 7 and Figure 8 FMS initializes the position vector p i (i = 1, j + 1, j + 2, j + 3):

[0152]

[0153] Where, λ to+j-1,to For L to+j-1 Longitude at point, l to+j-1,to For L to+j-1 Latitude of the point, λ to+j+1,to For L to+j+1 Longitude at point, l to+j+1,to For L to+j+1 Latitude of the point

[0154] Step 12.2, FMS calculates the unit vector q i (i = 1, 2):

[0155]

[0156] Step 12.3, FMS calculates the symbol turning direction dir:

[0157]

[0158] Step 12.4, FMS calculates the turning radius r:

[0159]

[0160] Step 12.5, FMS calculates p j+1 With p j+2 The distance d of the line j+(1→2) :

[0161] (~,~,d j+(1→2)) = PBD -1 (p j+1 ,p j+2 )

[0162] Step 12.6, if d j+(1→2) If the value is >2r, FMS will proceed to step 12.7; otherwise, it will proceed to step 9.15.

[0163] Step 12.7, FMS uses step 9 to calculate p turn,4 and p turn,5 That is: using p j+1 As its p1, use p j+2 As its p2, use p j+3 As its p3, the obtained p turn,1 Let p turn,4 p turn,2 Let p turn,5 ;

[0164] Step 12.8, FMS calculates the initial turning center p c,4 :

[0165]

[0166] Step 12.9, FMS calculates p j+2 With p j+1 The departure angle χ of the connecting line out,j+(2→1) :

[0167] (χ out,j+(2→1) ,~,~)=PBD -1 (p j+2 ,p j+1 )

[0168] Step 12.10, FMS calculates d1 using step 9.6, that is: using p j+2 As its p1, use χ out,j+(2→1) As its χ out,to , using p c,4 As its p c,1 and the obtained p (c,1)p Let p (c,4)p , χ out,(c,1)p→1b denoted as χ out,(c,4)p→(j+2) ;

[0169] Step 12.11: If d1 > r, FMS executes step 12.12; otherwise, it executes step 12.25.

[0170] Step 12.12, refer to Figure 6 FMS makes p turn,3 =p (c,4)p ;

[0171] Step 12.13, FMS calculates p turn,3 With p turn,4 The departure angle χ of the connecting line out,[turn,(3→4)] :

[0172] (χ out,[turn,(3→4)] ,~,~)=PBD -1 (p turn,3 ,p turn,4 )

[0173] Step 12.14, FMS calculates p c,3 :

[0174]

[0175] Step 12.15, FMS calculates p c,3 With p turn,3 The departure angle χ of the connecting line out,[(c→turn),3] :

[0176] (χ out,[(c→turn),3] ,~,~)=PBD -1 (p c,3 ,p turn,3 )

[0177] Step 12.16, FMS calculates p turn,2 :

[0178]

[0179] Step 12.17, FMS calculates p c,4 With p c,3 The departure angle χ of the connecting line out,[c,(4→3)] :

[0180] (χ out,[c,(4→3)] ,~,~)=PBD -1 (p c,4 ,p turn,3 )

[0181] Step 12.18, FMS calculates p turn,1 :

[0182]

[0183] Step 12.19, FMS calculates p turn,3 With p j+2 The departure angle χ of the connecting line out,[(turn,3)→(j+2)] and distance d (turn,3)→(j+2) :

[0184] (χ out,[(turn,3)→(j+2)] ,~,d (turn,3)→(j+2) ) = PBD -1 (p turn,3 ,pj+2 )

[0185] Step 12.20, FMS calculates p turn,3 With p turn,4 The distance d of the line turn,3→4 :

[0186] (~,~,d turn,3→4 ) = PBD -1 (p turn,3 ,p turn,4 )

[0187] Step 12.21, FMS calculates a temporary position vector p tmp :

[0188] p tmp =PBD(p turn,3 ,χ out,[(turn,3)→(j+2)] ,d turn,3→4 )

[0189] Step 12.22, if ||p tmp -p turn,4 If ||≤ε, FMS executes step 12.23; otherwise, it executes step 12.24.

[0190] Step 12.23, if d turn,3→4 -d (turn,3)→(j+2) If ε >, FMS executes step 12.24; otherwise, it executes step 13.

[0191] In step 12.24, FMS indicates that bypass is required, and then proceeds to step 13;

[0192] Step 12.25: If d1 = r, FMS executes step 12.31; otherwise, it executes step 12.26.

[0193] Step 12.26, refer to Figure 7 FMS calculates the initial turning center p c,4 :

[0194]

[0195] Step 12.27, FMS calculates ∠1:

[0196]

[0197] Step 12.28, FMS calculates p turn,2 :

[0198] p turn,2 =PBD(p c,4 ,χ out,(c,4)p→(j+2) +dir×∠1,r)

[0199] Step 12.29, FMS calculates p c,3 :

[0200] p c,3 =PBD(p turn,2 ,χ out,(c,4)p→(j+2) +dir×∠1,r)

[0201] Step 12.30, FMS calculates p turn,3 Then proceed to step 12.19:

[0202]

[0203] Step 12.31, refer to Figure 8 FMS makes p turn,3 =p (c,4)p Then proceed to step 12.19;

[0204] Step 13, FMS executes step 5;

[0205] Step 14, if segment L to+j-1 If bypass is allowed at the destination, FMS increments j and then executes step 1; otherwise, execute step 15.

[0206] Step 15, FMS calculates the turning points where bypass is prohibited:

[0207] Step 15.1, refer to Figure 9 FMS initializes the position vector p i (i = 1, 2, 3):

[0208]

[0209] Step 15.2, FMS calculates the unit vector q i (i = 1, 2):

[0210]

[0211] Step 15.3, FMS calculates the turning radius r:

[0212]

[0213] Step 15.4, FMS calculates Dubins paths of type left-right-left (LRL):

[0214] (L LRL ,p c,1,LRL ,p turn,2,LRL ,p c,2,LRL ,p turn,3,LRL ,pc,3,LRL =LRL(p1,q1,p2,q2)

[0215] Among them, L LRL This refers to the Dubins path length of type LRL, where LRL refers to the Dubins path algorithm of type LRL, which is not within the scope of this article.

[0216] Step 15.5, FMS calculates Dubins paths of type right turn-left turn-right turn (RLR):

[0217] (L RLR ,p c,1,RLR ,p turn,2,RLR ,p c,2,RLR ,p turn,3,RLR ,p c,3,RLR =RLR(p1,q1,p2,q2)

[0218] Among them, L RLR This refers to the length of a Dubins path of type RLR. RLR refers to the Dubins path algorithm of type RLR, which is not within the scope of this article.

[0219] Step 15.6, FMS determines p turn,2 and p turn,3 :

[0220]

[0221] Step 16: FMS sets to = to + j, j = 1, and then executes step 1.

[0222] The transition path construction methods provided in this embodiment for initial point turns, continuous point turns, point turns considering bypasses, and point turns prohibiting bypasses, as well as the bypass detection and processing methods for the above four types of point turns, are clear and concise. This embodiment processes the flight plan situation in which the point turn occurs separately, and ensures the continuity of the reference path with flight capability by defining the turning radius, detecting bypasses, and implementing bypass processing rules. It overcomes the problems of traditional methods for point turns at waypoints, which cannot guarantee accuracy, reliability, repeatability, and predictability. It can provide pilots, flight guides, and / or flight direction providers with a continuous and smooth reference track, support continuous and smooth RNP monitoring for pilots, enhance the reliability, repeatability, and predictability of aircraft flight paths, and thus improve the safety of flight in designated airspace.

[0223] It is understood that those skilled in the art can make equivalent substitutions or modifications to the technical solution and inventive concept of the present invention, and all such substitutions or modifications should fall within the protection scope of the appended claims.

Claims

1. A method for constructing the required navigation performance path for a flight management system to perform a point turn, characterized in that... It includes the following steps: Step 1, if the current flight segment L to and the next leg L to+j If it exists, proceed to step 2; otherwise, end. Step 2: If the current segment index to = 1 and the next segment index j = 1, proceed to step 3; otherwise, proceed to step 7. Step 3, if L to Perform a turn at the target point, then proceed to step 4, then proceed to step 6; Step 4: Calculate the initial turning point and detect bypass; Step 5: If a bypass exists, proceed to step 14; otherwise, proceed to step 16. Step 6, calculate other turns; Step 7: If j = 1, proceed to step 8; otherwise, proceed to step 11. Step 8, if L to If the turn is initiated, proceed to step 9; otherwise, proceed to step 6. Step 9: Calculate continuous point turns and detect bypasses; Step 10, proceed to step 5; Step 11, if L to+j If the turn is initiated, proceed to step 12; otherwise, proceed to step 6. Step 12, calculate the turning point considering bypass and detect bypass; Step 13, proceed to step 5; Step 14, if segment L to+j-1 If bypass is allowed at the destination, increment j and then execute step 1; otherwise, execute step 15. Step 15, calculate the turning points where bypassing is prohibited; Step 16: Let to = to + j, j = 1, and then execute step 1.

2. The method for constructing the required navigation performance path for a flight management system to perform a point turn according to claim 1, characterized in that... Step 4, calculating the initial directional turn and detecting bypass, includes the following steps: Step 4.1, initialize the position vector p i (i = 1, 2, 3): Where, λ to,from For L to From the longitude of the point, l to,from For L to From the point latitude, λ to,to For L to Longitude at point, l to,to For L to Latitude of the point, λ to+j,to For the next leg L to+j From the longitude of the point, l to+j,to For L to+j From point latitude; Step 4.2, calculate the unit vector q i (i = 1, 2): Step 4.3, calculate the turning direction (dir) of the symbol: Where ε is the set minimum value, q i,x (i = 1, 2) (x = 1, 2) are vectors q i The x-th value of (i = 1, 2); Step 4.4, calculate the turning radius r: Among them, v g φ is the ground speed for turning at a specified direction point, φ is the roll angle for turning at a specified direction point, and g is the acceleration due to gravity. Step 4.5, if L to >r indicates that a bypass is needed, then proceed to step 5; otherwise, proceed to steps 4 and 6. Step 4.6, calculate the turning center p of the turning point. c : PBD refers to an algorithm that calculates the target's position and angle of entry based on a given location, bearing, and distance. χ out,to+j For L to+j The departure angle; Step 4.7, calculate the distance from the turning center to L. to Distance d from point r And azimuth angle χ: (χ,~,d r )=PBD -1 (p c ,p1) Among them, PBD -1 This refers to the inverse solution algorithm of the PBD algorithm; Step 4.8, if d r >r indicates that a bypass is needed, then proceed to step 5; otherwise, proceed to step 4.

9. Step 4.9, calculate L to The line connecting point A to the center of the turn and L to The angle Δχ between the lines connecting point A to the turning point A: Where, r e The radius of the Earth; Step 4.10, calculate the turning point p. turn :

3. The method for constructing the required navigation performance path for a flight management system to perform a point turn according to claim 1, characterized in that... Step 9, calculating continuous point turns and detecting bypasses includes the following steps: Step 9.1, initialize the position vector p i (i = 1, 2, 3): Step 9.2, calculate the unit vector q i (i = 1, 2): Step 9.3, calculate the turning direction of the symbol dir: Step 9.4, calculate the turning radius r: Step 9.5, calculate the turning center p at the direction point. c,1 : Step 9.6, calculate the distance from the starting turning center to L. to Projected distance d1: Step 9.7, calculate the line connecting the starting turn and the turning center at the point of reference, and L. to The included angle ∠1: Step 9.8, calculate p turn,2 : p turn,2 =PBD(p c,1 ,χ in,to +π-dir×∠1,r) Where, χ in,to For L to angle of entry; Step 9.9, calculate the initial turning center p c,2 : p c,2 =PBD(p turn,2 ,χ in,to +π-dir×∠1,r) Step 9.10, calculate the initial turning entry point p. turn,1 : Step 9.11, calculate p1 and p turn,1 The distance d of the line 1→(turn,1) : (~,~,d 1→(turn,1) )=PBD -1 (p1,p turn,1 ) Step 9.12, calculate a temporary position vector p tmp : p tmp =PBD(p1,χ out,to ,d 1→(turn,1) ) Step 9.13, if ||p tmp -p turn,1 If ||≤ε, proceed to step 9.14; otherwise, proceed to step 9.

15. Step 9.14, if d 1→(turn,1) -d to If ε > , proceed to step 9.15; otherwise, proceed to step 10, where d to For L to Length; Step 9.15 indicates that a bypass is needed, then proceed to step 10.

4. The method for constructing the required navigation performance path for a flight management system to perform a point turn according to claim 3, characterized in that... Step 9.6, calculate the distance from the starting turning center to L. to The projection distance d1 includes the following steps: Step 9.6.1, initialize p 1b =p1, χ out,1b→(c,1)p =χ out,to , where χ out,to For L to The departure angle; Step 9.6.2, calculate from p 1b to p c,1 distance d 1b→(c,1) Departure angle χ out,1b→(c,1) and angle of entry χ in,1b→(c,1) : (χ out,1b→(c,1) ,χ in,1b→(c,1) ,d 1b→(c,1) )=PBD -1 (p 1b ,p c,1 ) Step 9.6.3, from χ out,1b→(c,1)p To χ out,1b→(c,1) azimuth change No [out,1b→(c,1)p]→[out,1b→(c,1)] : Step 9.6.4, if d 1b→(c,1) ≤ε, let d1=d 1b→(c,1) Then proceed to step 9.7; otherwise, proceed to step 9.6.

5. Step 9.6.5, if Proceed to step 9.6.6; otherwise, proceed to step 9.6.

12. Step 9.6.6, let Step 9.6.7, calculate from p 1b to p c,1 In L to Upper projection point p (c,1)p distance d 1b→(c,1)p : Step 9.6.8, if d 1b→(c,1)p <ε, let d1=d 1b→(c,1) Then proceed to step 9.7; otherwise, proceed to step 9.6.

9. Step 9.6.9, calculate a temporary position vector p tmp : p tmp =PBD(p 1b ,x out,1b→(c,1)p +π,1.1×d 1b→(c,1)p ) Step 9.6.10, update χ out,1b→(c,1)p : (χ out,1b→(c,1)p ,~,~)=PBD -1 (p tmp ,p 1b ) Step 9.6.11, let p 1b =p tmp ; Step 9.6.12, update d using steps 9.6.2 to 9.6.

7. 1b→(c,1)p ; Step 9.6.13, initialize p (c,1)p =PBD(p 1b ,χ out,1b→(c,1)p ,d 1b→(c,1)p ); Step 9.6.14, calculate from p (c,1)p to p 1b angle of entry χ out,(c,1)p→1b : (χ out,(c,1)p→1b ,~,~)=PBD -1 (p (c,1)p ,p 1b ) Step 9.6.15, calculate from p (c,1)p to p c,1 departure angle χ out,(c,1)p→(c,1) and d1: (χ out,(c,1)p→(c,1) ,~,d1)=PBD -1 (p (c,1)p ,p c,1 ) Step 9.6.16, calculate from χ out,(c,1)p→1b To χ out,(c,1)p→(c,1) azimuth change Δχ [out, ( c,1 ) p→1b]→[out, ( c,1 ) p→ ( c,1 ) ] : Step 9.6.17, calculate the angular error e1: Step 9.6.18, let d 1b→(c,1)p,1 =d 1b→(c,1)p ; Step 9.6.19, calculate p considering e1. 1b to p (c,1)p distance d 1b→(c,1)p,2 : d 1b→(c,1)p,2 =d 1b→(c,1)p,1 +e1×d1 Step 9.6.20, update p (c,1)p : p (c,1)p =PBD(p 1b ,χ out,1b→(c,1)p ,d 1b→(c,1)p,2 ) Step 9.6.21, update χ out,(c,1)p→1b : (χ out,(c,1)p→1b ,~,~)=PBD -1 (p (c,1)p ,p 1b ) Step 9.6.22, update χ out,(c,1)p→(c,1) : (χ out,(c,1)p→(c,1) ,~,~)=PBD -1 (p (c,1)p ,p c,1 ) Step 9.6.23, calculate the new angular error e2: Step 9.6.24, initialize k = 1; Step 9.6.25, if k = 1, or |d 1b→(c,1)p,2 -d 1b→(c,1)p,1 |>ε and k max , where I max If the maximum number of iterations is reached, proceed to step 9.6.26; otherwise, proceed to step 9.7.​ Step 9.6.26, FMS update d 1b→(c,1)p : Step 9.6.27, update p (c,1)p : p (c,1)p =PBD(p 1b ,χ out,1b→(c,1)p ,d 1b→(c,1)p ) Step 9.6.28, update χ out,(c,1)p→1b : (χ out,(c,1)p→1b ,~,~)=PBD -1 (p (c,1)p ,p 1b ) Step 9.6.29, update d1 and χ out,(c,1)p→(c,1) : (χ out,(c,1)p→(c,1) ,~,d1)=PBD -1 (p (c,1)p ,p c,1 ) Step 9.6.30, let k = k + 1, d 1b→(c,1)p,1 =d 1b→(c,1)p,2 e1 = e2, d 1b→(c,1)p,2 =d 1b→(c,1)p , Then proceed to step 9.6.

25.

5. The method for constructing the required navigation performance path for a flight management system to perform a point turn according to claim 4, characterized in that... Step 12, calculating the turning point considering bypass and detecting bypass, includes the following steps: Step 12.1, initialize the position vector p i (i = 1, j + 1, j + 2, j + 3): Where, λ to+j-1,to For L to+j-1 Longitude at point, l to+j-1,to For L to+j-1 Latitude of the point, λ to+j+1,to For L to+j+1 Longitude at point, l to+j+1,to For L to+j+1 Latitude of the point Step 12.2, calculate the unit vector q i (i = 1, 2): Step 12.3, calculate the turning direction of the symbol dir: Step 12.4, calculate the turning radius r: Step 12.5, calculate p j+1 With p j+2 The distance d of the line j+(1→2) : (~,~,d j+(1→2) )=PBD -1 (p j+1 ,p j+2 ) Step 12.6, if d j+(1→2) If the value is >2r, FMS will proceed to step 12.7; otherwise, it will proceed to step 9.

15. Step 12.7, use step 9 to calculate p turn,4 and p turn,5 That is: using p j+1 As its p1, use p j+2 As its p2, use p j+3 As its p3, the obtained p turn,1 Let p turn,4 p turn,2 Let p turn,5 ; Step 12.8, calculate the initial turning center p c,4 : Step 12.9, calculate p j+2 With p j+1 The departure angle χ of the connecting line out,j+(2→1) : (χ out,j+(2→1) ,~,~)=PBD -1 (p j+2 ,p j+1 ) Step 12.10, calculate d1 using step 9.6, that is: using p j+2 As its p1, use χ out,j+(2→1) As its χ out,to , using p c,4 As its p c,1 and the obtained p (c,1)p Let p (c,4)p , χ out,(c,1)p→1b denoted as χ out,(c,4)p→(j+2) ; Step 12.11: If d1 > r, proceed to step 12.12; otherwise, proceed to step 12.

25. Step 12.12, let p turn,3 =p (c,4)p ; Step 12.13, calculate p turn,3 With p turn,4 The departure angle χ of the connecting line out,[turn,(3→4)] : (χ out,[turn,(3→4)] ,~,~)=PBD -1 (p turn,3 ,p turn,4 ) Step 12.14, calculate p c,3 : Step 12.15, calculate p c,3 With p turn,3 The departure angle χ of the connecting line out,[(c→turn),3] : (χ out,[(c→turn),3] ,~,~)=PBD -1 (p c,3 ,p turn,3 ) Step 12.16, calculate p turn,2 : Step 12.17, calculate p c,4 With p c,3 The departure angle χ of the connecting line out,[c,(4→3)] : (χ out,[c,(4→3)] ,~,~)=PBD -1 (p c,4 ,p turn,3 ) Step 12.18, calculate p turn,1 : Step 12.19, calculate p turn,3 With p j+2 The departure angle χ of the connecting line out,[(turn,3)→(j+2)] and distance d (turn,3)→(j+2) : (χ out,[(turn,3)→(j+2)] ,~,d (turn,3)→(j+2) )=PBD -1 (p turn,3 ,p j+2 ) Step 12.20, calculate p turn,3 With p turn,4 The distance d of the line turn,3→4 : (~,~,d turn,3→4 )=PBD -1 (p turn,3 ,p turn,4 ) Step 12.21, calculate a temporary position vector p tmp : p tmp =PBD(p turn,3 ,χ out,[(turn,3)→(j+2)] ,d turn,3→4 ) Step 12.22, if ||p tmp -p turn,4 If ||≤ε, proceed to step 12.23; otherwise, proceed to step 12.

24. Step 12.23, if d turn,3→4 -d (turn,3)→(j+2) If the value is >ε, proceed to step 12.24; otherwise, proceed to step 13. Step 12.24 indicates that a bypass is needed, then proceed to step 13; Step 12.25: If d1 = r, execute step 12.31; otherwise, execute step 12.

26. Step 12.26, calculate the initial turning center p c,4 : Step 12.27, calculate ∠1: Step 12.28, calculate p turn,2 : p turn,2 =PBD(p c,4 ,χ out,(c,4)p→(j+2) +dir×∠1,r) Step 12.29, calculate p c,3 : p c,3 =PBD(p turn,2 ,χ out,(c,4)p→(j+2) +dir×∠1,r) Step 12.30, calculate p turn,3 Then proceed to step 12.19: Step 12.31, let p turn,3 =p (c,4)p Then proceed to step 12.

19.

6. The method for constructing the required navigation performance path for a flight management system to perform a point turn according to claim 1, characterized in that... Step 15, calculating the turning point where bypass is prohibited, includes the following steps: Step 15.1, initialize the position vector p i (i = 1, 2, 3): Step 15.2, calculate the unit vector q i (i = 1, 2): Step 15.3, calculate the turning radius r: Step 15.4, calculate the Dubins path of type left-right-left: (L LRL ,p c,1,LRL ,p turn,2,LRL ,p c,2,LRL ,p turn,3,LRL ,p c,3,LRL )=LRL(p1,q1,p2,q2) Among them, L LRL LRL is the length of a Dubins path of type left-right-left, where LRL refers to the Dubins path algorithm of type left-right-left. Step 15.5, calculate the Dubins path of the right-left-right type: (L RLR ,p c,1,RLR ,p turn,2,RLR ,p c,2,RLR ,p turn,3,RLR ,p c,3,RLR )(RLR(p1,q1,p2,q2) Among them, L RLR RLR refers to the length of a right-left-right type Dubins path, where RLR is the right-left-right type Dubins path algorithm. Step 15.6, determine p turn,2 and p turn,3 :

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