Trajectory design method for online height adjustment of cruise section of supersonic aircraft

Abstract

Disclosed is a trajectory design method for online height adjustment of a cruise section of a supersonic aircraft, comprising the following steps: dividing the cruise height into a climbing cruise height section and. a descending cruise height section according to the cruise height range of the supersonic aircraft, and obtaining a trajectory database; performing normalization processing on the height instruction of any flight profile to obtain a new trajectory database; when the supersonic aircraft receives a target cruise height instruction, calling the new trajectory database, and obtaining a ballistic trajectory voyage, a ballistic trajectory dip angle instruction and an attack angle instruction under the target cruise height instruction; obtaining all ballistic trajectory instructions of the flight. profile corresponding“ to the target cruise height. The present invention solves the problem that in the prior art, the ballistic trajectory instruction for adjusting the cruise height cannot be rapidly and accurately generated.

Description

TECHNICAL FIELD

[01] The present invention relates to the field of spaceflight, and particularly relates to a trajectory design method for online height adjustment of a cruise section of a supersonic aircraft. BACKGROUND ART

[02] A supersonic aircraft has been a research hotspot in global advanced aircrafts by virtue of its capability advantages such as high speed, longdistance cruise flight and superior penetration capability. As important military equipment in modern weapon wars, the supersonic aircraft is also one of the criteria for measuring the current comprehensive national strength of countries. With the in depth research. on the cruise section of the supersonic aircraft, the flight advantages of the supersonic aircraft in highaltitude, mediumaltitude and lowaltitude cruise flights are not the same; due to reduction of air density, a cruise state in the high-altitude cruise flight can reduce the resistance of the aircraft and help the aircraft to achieve a higher flight speed with lower fuel consumption; a cruise state in the lowaltitude cruise flight can enhance the stealthiness of the aircraft and reduce the difficulty of countermeasures, so the cruise height of the supersonic aircraft varies depending on the nature of a flight mission; with the demands of operational scenarios in Inodernized wars, operational missions to be completed. by military equipment such. as supersonic aircrafts have become more complex and variable, these missions are not performed in a traditional singlemission mode any longer but require a flexible shift towards a Hmltimission mode in order to further improve an operational capability of the aircraft; an online adjustment of the cruise height in a cruise phase according" to different mission requirements and terrain environments allows rapid planning of an adjusted flight ballistic trajectory to achieve the online adjustment of the cruise height of the supersonic aircraft in the cruise section. [O3] As the supersonic aircraft has the characteristics of high speed and longdistance cruise flight, the research on online trajectory planning has difficulty in taking a step, and the problem that how to rapidly and accurately generate the ballistic trajectory instruction for adjusting the cruise height for the aircraft online in the cruise section of the supersonic aircraft has become an urgent problem to be solved. SUMMARY

[04] In response to the above deficiencies in the prior art, the present invention provides a trajectory design method for online height adjustment of a cruise section of a supersonic aircraft, which solves the problem that in the prior art, the ballistic trajectory instruction for adjusting the cruise height cannot be rapidly and accurately generated for the aircraft online in the cruise section of the supersonic aircraft.

[05] To achieve the above-mentioned objective of the present invention, the technical solution used by the present invention is: a trajectory design method for online height adjustment. of a. cruise section. of a. supersonic aircraft includes the following steps:

[06] Sl: dividing the cruise height into a climbing cruise height section and a descending cruise height section according to the cruise height variation range of the supersonic aircraft, planning the ballistic trajectory instruction for each flight profile, and obtaining a trajectory database; [O7] SZ: performing normalization processing on the height instruction of any flight profile based on the trajectory database to obtain a new trajectory database;

[08] S3: when the supersonic aircraft receives a target cruise height instruction, calling the new trajectory database, and obtaining a ballistic trajectory voyage, a ballistic trajectory dip angle instruction and an attack angle instruction obtained.by linear interpolation according . . . . h to the normalized height instruction ? under the target cruise height instruction he in accordance with the target cruise height instruction he and a linear interpolation between the two adjacent target cruise heights h and hb in the new trajectory database;

[09] S4: calculating a height variation factor KF according to the target cruise height instruction he, an initial . . . . h cruise height % and a target cruise height g under the normalized height instruction in the new trajectory database; . . . . . h

[10] S5: restoring the normalized height instruction & to the actual ballistic trajectory height instruction @ according to the target cruise height instruction he and the height variation factor Kl; and

[11] S6: according to the actual ballistic trajectory height instruction hl, as well as the ballistic trajectory voyage, the ballistic trajectory dip angle instruction and the attack angle instruction obtained by linear interpolation . . . . . h according to the normalized height instruction , obtaining all ballistic trajectory instructions of the flight profile corresponding to the flight to the target cruise height, and. completing' the trajectory design for online height adjustment of the cruise section of the supersonic aircraft.

[12] Further, the Sl includes the following substeps:

[13] Sll: dividing the cruise height into a climbing height section and a descending height section according to the cruise height variation range of the supersonic aircraft;

[14] 812: setting a target cruise height of a plurality of equally spaced heights based on the division results, and using the target cruise height of the plurality of equally spaced heights as a flight profile; and

[15] Sl3: designing a ballistic trajectory instruction for each flight profile, and arranging the ballistic trajectory instructions sequentially to obtain a trajectory database.

[16] Further, the process of dividing the cruise height into a climbing height section and a descending height section in the S11 includes the following situations:

[17] (1) when the target cruise height @ received by the supersonic aircraft is greater than an initial cruise height ho, the cruise height is divided into a climbing height section;

[18] (2) when the target cruise height @ received by the supersonic aircraft is not greater than the initial cruise height ho, the cruise height is divided into a descending height section.

[19] Further, the ballistic trajectory instruction in the Sl3 includes a ballistic trajectory height instruction hc, a ballistic trajectory dip angle instruction a and a ballistic attack angle instruction ac obtained by linear interpolation of the flight voyage.

[20] Further, the SZ includes the following substeps:

[21] 821: selecting the ballistic trajectory height instruction of any flight profile as the normalized height instruction h? based on the ballistic trajectory instructions in the trajectory database, and obtaining the ballistic trajectory instruction of the normalized height instruction h? under different target cruise heights within the remaining flight profiles;

[22] S22: creating a new trajectory database based on the ballistic trajectory instruction of the normalized height instruction hg.

[23] Further, the height variation factor KF in the S4 is: K'=hg% h

[24] hfho .

[25] Further, the actual ballistic trajectory height instruction hz in the SS is: hz=w+h0

[26] Kh .

[27] The present invention has the beneficial effects that: using a method for online rapid generation of a ballistic trajectory of the present invention, the ballistic trajectory data at some target cruise heights can be planned offline on the ground, all the ballistic trajectories within the cruise height range are generated rapidly in the flight process, and the trajectory design method of the present invention solves the problem that in the prior art, the ballistic trajectory instruction for adjusting the cruise height cannot be rapidly and accurately generated for the aircraft online in the cruise section of the supersonic aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[28] FIG. 1 is a schematic flow chart of a trajectory generation method for online cruise height adjustment of a cruise section of a supersonic aircraft described in the present invention.

[29] FIG. 2 is a curve graph of the attack angle vs. height variation planned offline at an initial cruise height of 25 km.

[30] FIG. 3 is a curve graph of the voyage vs. height variation planned offline at an initial cruise height of 25 km.

[31] FIG. 4 is a curve graph of the ballistic trajectory dip angle vs. height variation planned offline at the initial cruise height of 25 km.

[32] FIG. 5 is a curve graph of the attack angle vs. height variation stored in a new trajectory database.

[33] FIG. 6 is a curve graph of the voyage vs. height variation stored in the new trajectory database.

[34] FIG. 7 is a curve graph of the ballistic trajectory dip angle vs. height variation stored in the new trajectory database.

[35] FIG. 8 is a curve graph of the attack angle vs. height variation at a target cruise height of 26.25 km obtained from the data in the new trajectory database.

[36] FIG. 9 is a curve graph. of the voyage vs. height variation at a target cruise height of 26.25 km obtained from the data in the new trajectory database.

[37] FIG. 10 is a curve graph of the ballistic trajectory dip angle vs. height vs. height variation at a target cruise height of 26.25 km obtained from. the data in the new trajectory database.

[38] FIG. 11 is a curve graph of the attack angle instruction. vs. normalized. height variation. at a target cruise height of 26.25 km.

[39] FIG. 12 is a curve graph of the voyage vs. normalized height variation at a target cruise height of 26.25 km.

[40] FIG. 13 is a curve graph of the ballistic trajectory dip angle instruction vs. normalized height variation at a target cruise height of 26.25 km.

[41] FIG. 14 is a curve graph of the attack angle instruction vs. voyage variation at a target cruise height of 26.25 km.

[42] FIG. 15 is a curve graph of the height instruction vs. voyage variation at a target cruise height of 26.25 km.

[43] FIG. 16 is a curve graph of the ballistic trajectory dip angle instruction. vs. voyage variation at a target cruise height of 26.25 km.

[44] FIG. 17 is a curve graph of the height vs. voyage variation simulated by the attack angle instruction generated online at a target cruise height instruction of 26.25 km.

[45] FIG. 18 is a curve graph of the ballistic trajectory dip angle vs. voyage variation simulated by the attack angle instruction generated. online at a target cruise height instruction of 26.25 km. DETAILED DESCRIPTION OF THE EMBODIMENTS

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

[47] To adapt to the demands of operational scenarios in modernized wars in the future, the supersonic aircraft in the present invention needs to have the capability of dealing with a multimission mode as far as possible, so as to realize the completion of different operational missions at different cruise heights, and therefore, the supersonic aircraft needs to have the capability of planning a ballistic trajectory curve of a changed cruise height; the supersonic aircraft has the characteristic of high flight speed, so that the time requirements for the online generation of a height variation trajectory for the supersonic aircraft are quite demanding. Accordingly, the present invention provides a trajectory design method for online height adjustment of a cruise section of a supersonic aircraft in order to solve the problem that a supersonic aircraft can rapidly plan a ballistic trajectory for arriving at a new cruise height state online in the cruise section.

[48] The main idea of the method is to: design a ballistic trajectory instruction for a supersonic aircraft using the target cruise height set with equally spaced heights (such as 500 m) as a flight profile in accordance with the cruise height range of the supersonic aircraft, and a trajectory database covering the entire flight height is formed. Normalization processing is performed on the target cruise height under each flight profile in the trajectory database, and the flight profile data under the nonnormalized target cruise height are reselected to obtain a new trajectory database under the normalized height. When a target cruise height instruction is received, the new trajectory database is called, the instruction data of the ballistic trajectory instruction at the normalized height at this target cruise height are obtained, ther1 a height variation factor is obtained. using a weight relationship between. the target cruise height to be achieved and two adjacent cruise heights in the trajectory database, and the normalized height is restored to the actual trajectory height instruction, so as to achieve the rapid generation of the ballistic trajectory instruction for the flight profile of any target cruise height.

[49] The present invention is an online rapid. planning method for a variable height trajectory of a supersonic aircraft, where an optimal trajectory curve for flight to a target cruise height of spaced heights is designed on the ground at first; then normalization processing is performed on the height for the target cruise height trajectory of these spaced heights, and a new trajectory database of the normalized. height h is obtained. under different target cruise heights; when the aircraft receives the target cruise height instruction & in the flight process, the new trajectory database is called, and the remaining ballistic trajectory instructions in addition to the height when flying to this cruise height @ are calculated using the weight relationship between the received target cruise height @ and the two adjacent cruise heights % and % ( ha<hh) 1J1 the new trajectory database; then the height variation factor K4 is calculated according to the target cruise heights hg under the target cruise height instruction & and the initial cruise height % and normalized height instruction, the normalized height instruction hg in the database is restored to the actual trajectory height instruction hf to obtain all the ballistic trajectory instructions under the cruise height he, so as to realize rapid generation of the ballistic trajectory instruction of the flight profile at any cruise height within the cruise height range of the supersonic aircraft.

[50] Based on the above principle, an online fast planning method for a variable height trajectory of a supersonic aircraft includes the following steps, as shown in FIG. 1:

[51] In S1, the cruise height is divided into a climbing height section and a descending height section according to the cruise height variation range of the supersonic aircraft; when the target cruise height he received by the aircraft is greater than an initial cruise height ho, the cruise height is categorized as the climbing height section, and conversely, the cruise height is categorized as the descending height section; according to the upper and lower height limits of the height section, a plurality of set heights are obtained in accordance with equal height steps, and a ballistic trajectory instruction of the flight profile is planned offline for each set height in accordance with the flight voyage, including the ballistic actual height instruction hf , the ballistic trajectory dip angle instruction & and.the attack angle instruction ac obtained by linear interpolation of the flight voyage Â; and the flight profile ballistic trajectory instructions at all set heights are arranged. in the height sequence to form. a trajectory database.

[52] In one embodiment of the present invention, a full process is divided into two parts: offline trajectory planning processing and online trajectory generation. The first part is the offline trajectory planning processing part: assuming that the initial cruise height of the supersonic aircraft is 25 km, the cruise height is divided into a climbing height section 25.527.5 km and a descending height section 2324.5 km according to the cruise height variation range of the supersonic aircraft; when the target cruise height % received by the aircraft is greater than the initial cruise height, the cruise height is set as the climbing height section, and conversely, the cruise height is set as the descending height section; according to the upper and lower height limits of the height section, five set heights of the climbing height section and four set heights of the descending height section are obtained in accordance with an equally spaced height of 500 m, and a ballistic trajectory instruction of the flight profile is planned offline for each set height in accordance with the flight voyage, including the ballistic actual height instruction hf , the ballistic trajectory dip angle instruction & and.the attack angle instruction ac obtained by linear interpolation of the flight voyage ÄÏ; the flight profile ballistic trajectory instructions at all set heights are arranged in the height sequence to form an original trajectory database, as shown in FIGs. 24.

[53] In S2, the height instruction of one of the flight profiles in the ballistic trajectory height instruction h ballistic trajectory" dip angle instruction Q: and. attack angle instruction ac arranged in the flight height sequence is taken as the normalized height instruction kg, the ballistic trajectory instruction of the normalized height instruction h? at different target cruise heights in the remaining' flight. profiles is obtained, a new trajectory database is created for this, and at this time, the offline planning mission on the ground is completed.

[54] For these ballistic trajectory instructions, i.e., the height instruction he, the ballistic trajectory dip angle instruction & and the attack angle instruction ac, which are arranged in the sequence of flight heights, a height in the climbing height section of 2527.5 km is selected as a normalized height in the climbing section, a height in the descending' height section. of 2523 km. is selected. as a normalized height in the descending section, the ballistic trajectory instruction at the normalized height at different target cruise heights is obtained, a new trajectory database is created for this, as shown in FIGs. 57, and the offline planning processing mission on the ground is completed once the above steps are completed.

[55] In S3, when the aircraft receives a target cruise height instruction he in the process of cruise flight, a new trajectory database is called, and a ballistic trajectory voyage XT, a ballistic trajectory dip angle instruction a and an attack angle instruction. ac obtained by linear interpolation according to the normalized height instruction h? under the target cruise height instruction % are obtained in accordance with the target cruise height instruction & and a linear interpolation between the two adjacent target cruise heights h and hb in the database.

[56] In the process of cruise flight, assuming that the aircraft receives a target cruise height instruction he=2625bn, i.e., after the aircraft is required to climb from a cruise height of 25 km to a cruise height of 26.25 km, a new trajectory database is called, a ballistic trajectory instruction of the normalized height h? with the aircraft climbing to a height of 26.25 km through a linear interpolation performed between 26.25 km and two adjacent target cruise heights in the new trajectory database, as well as a ballistic trajectory voyage AY, a. ballistic trajectory dip angle instruction 5% and. an attack angle instruction ac obtained. by linear interpolation in accordance with the normalized height h? are obtained, so as to obtain the variations in the voyage ÄÏ, the ballistic trajectory dip angle instruction & and the attack angle instruction ac with the normalized height h under the new trajectory database, as shown in FIGs. 810.

[57] In. S4, a height variation factor 5% is calculated according to the target cruise height hq the initial cruise height % and the target cruise height @? under the normalized height instruction:

[58] he_h0

[59] where h? is the target cruise height instruction received by the aircraft, hg is the normalized height stored in the new trajectory database, and ho is the initial cruise height.

[60] At the initial cruise height hOZZSbn, the target cruise height instruction he=2625bn, the normalized cruise height h? of the climbing section and the initial cruise height h0=25bn , the height variation factor K4 is calculated:

[61] C 0 ' .

[62] In 85, the normalized height instruction h is restored to the actual ballistic trajectory height instruction hz based on the target cruise height he and the height variation factor K4; hz =+h0

[63] Kh .

[64] In S6, all the ballistic trajectory instructions for flight to a flight profile corresponding to the target cruise height he are obtained from the ballistic trajectory height instruction % restored from S5, together with the ballistic trajectory dip angle instruction &? and the attack angle instruction ac obtained in S3.

[65] Curves of the attack angle instruction ac vs. actual height @ variation, the voyage ÄÏ vs. actual height @ variation, and the ballistic trajectory dip angle instruction Q: vs. actual height hz variation under the flight profile corresponding to the flight to the target cruise height he=2625bn are obtained 1J1 this embodiment. The results are shown in FIGs. 1113, and the generated curves of the attack angle instruction ac vs. voyage variation, the height instruction hz vs. Voyage variation, and the ballistic trajectory dip angle instruction @ vs. voyage variation are shown in FIGs. 1416.

[66] To verify the consistency of the height instruction and the ballistic trajectory dip angle instruction generated online through the trajectory database with the height and ballistic trajectory dip angle curves simulated. by the attack angle instruction generated online, simulation and verification. are performed. by bringing' the attack angle instruction generated online into a threedegreesof freedom kinematic model, and the simulation result of the height ballistic curve and the ballistic trajectory dip angle curve is shown in FIGs. 1718, which reveals that: there is a good consistency of the generated. ballistic trajectory height instruction and the ballistic trajectory dip angle instruction with the height and the ballistic trajectory dip angle simulated. by the kinematic model. Therefore, it is possible to achieve offline planning of ballistic trajectory" data at some of the target cruise heights on the ground by using the method for online rapid generation of a ballistic trajectory of the present invention.

[67] Those of ordinary skill in the art will realize that the embodiments described. herein. are intended. to assist readers in understanding the principles of the present invention, and this should be construed as no limitations on the protection scope of the present invention to such particular statements and embodiments. Those of ordinary skill in the art may make various other specific deformations and combinations according to these technical inspirations disclosed. in the present invention without departing from the essence of the present invention, and these deformations and. combinations still fall into the protection scope of the present invention.

Claims

l. Track design method for online height adjustment of a cross section of a supersonic aircraft, including the following steps: Sl: dividing the cruising altitude into a climbing cruising altitude section and a descending cruising altitude section according to the cruise altitude variation range of the supersonic air vessel, planning the ballistic trajectory instruction for each flight profile, and obtaining a runway date tabase; S2: Performing normalization processing' on the altitude instruction of any flight profile based on the track database to obtain a new track database; S3: When the supersonic aircraft is in receives instruction for target cruising altitude, calling it of the new course database, and obtaining a ball listic track journey, an instruction for the dip angle of the ballistic trajectory and an instruction for "the angle of attack" obtained by linear interpolation according to the normalized seerde height instruction h according to the instruction he for the target cruising altitude in accordance with the instruction for the target cruising altitude and. a linear interpolation between the two adjacent target cross-heights h and hb in the new track database; S4: Calculating a height variation factor Kl according to the instruction for the target cruising altitude, a ini target cruising height ho and a target cruising height hg according to the instruction for the standardized height in the new track database; SS: Restoring the normalized height instruction h to the current ballistic trajectory altitude instruction hz according to the target cross height instruction he and the height variation factor Kl; and S6: According to the current instruction of the ballistic orbital height hZ, as well as the ballistic trajectory, the in instruction of the dip angle of the ballistic trajectory and the in instruction of the angle of attack obtained by linear interpolation according to the standardized height instruction is obtained genh, getting all ballistic trajectory instructions ties of the flight profile that correspond to the flight to the target cruising altitude, and completing the runway design cast for online height adjustment' of the crotch section of the supersonic aircraft.

2. Track design method for online height adjustment of a cross section of a supersonic aircraft according to claim 1, wherein step S1 comprises the following part steps include: 811: dividing the crossing height into a climb the height and a decreasing height according to the range of the cruising altitude of the supersonic aircraft; Sl2: Setting a target cruise altitude of a multiple of equally distributed heights based on the distance division results, and the use of the target cruising altitude of the multiple of equally distributed heights as a flight profile; and Sl3: Designing a Ballistic Trajectory Instruction tie for each flight profile and the sequential arrangement know the ballistic trajectory instructions to create a trajectory database can be obtained.

3. Track design method for online height adjustment of a cross section of a supersonic aircraft of claim 2, wherein the process of dividing the cruising altitude in a climbing altitude section and a descending altitude section the height section in step Sll the following situations to barrel: (1) when the target cruising altitude is that determined by the super sonic aircraft is received is greater than a initial cruise altitude h, then the cruise altitude is divided in a climbing elevation section; (2) when the target cruising altitude is that determined by the super sonic aircraft is received is not greater than the initial cruise altitude ho, then the cruise altitude ver divided into a descending elevation section.

4. Track design method for online height adjustment of a cross section of a supersonic aircraft according to claim 2, wherein the instruction for the ballis tic path in step Sl3 an instruction for the height of the ballistic trajectory height hc, an instruction for the dip angle of the ballistic trajectory and an instruction for the ballistic angle of attack ac, obtained by linear interpolation of the flight journey, includes.

5. Track design method for online height adjustment of a cross section of a supersonic aircraft of claim 1, wherein step 82 comprises the following sub-steps barrel: S21: Selecting the ball instruction listic trajectory altitude of any flight profile as the in instruction for the normalized height h based on the instructions for the ballistic trajectory in the trajectory database, and obtaining the instruction for the ballistic path of the instruction for normalized height h on of the different target cruising altitudes within the other flight profiles; 822: Creating a new track database on ba sis of the ballistic trajectory instruction of the normalized seerde height instruction h.

6. Track design method for online height adjustment of a cross section of a supersonic aircraft according to claim 1, wherein the height variation factor Kh in step 84 is: =hgh0 _ heh0 _ 7. Track design method for online height adjustment of a cross section of a supersonic aircraft of claim 1, wherein the current instruction for the ballistic trajectory height hz in step 85 is: h ,h hz=gL0+h0 Kh oooo Start S1: Dividing the cruise height into a climbing cruise height section and a descending cruise height section according to the cruise height variation range of the supersonic rcraft, planning the ballistic trajectory instruction for each flight profile, and obtaining a trajectory database S2: Performing normalization processing on the height instruction of any flight profile based on the trajectory database to obtain a new trajectory database S3: When the supersonic aircraft receives a target cruise height instruction, calling the new trajectory database, and obtaining a ballistic trajectory voyage, a ballistic trajectory dip angle instruction and an attack angle instruction obtained by linear interpolation cording to the normalized height instruction under the target cruise height instruction ccordance with the target cruise height instruction and a linear interpolation between the two adjacent target cruise heights in the new trajectory database S4: Calculating a height variation factor according to the target cruise height instruction, nitial cruise height and a target cruise height under the normalized height instruction in the new trajectory database S5: Restoring the normalized height instruction to the actual ballistic trajectory height instruction according to the target cruise height instruction and the height variation factor S6: According to the actual ballistic trajectory height instruction, as well as the ballistic trajectory voyage, the ballistic trajectory dip angle instruction and the attack angle instruction obtained by linear interpolation according to the normalized height instruction, obtaining all ballistic trajectory instructions of the flight profile corresponding to the flight to the target cruise height, and completing the trajectory design for online height adjustment of the cruise section of the supersonic aircraft End FIG. 1 α-h curve graph at h0=25 km Height h (km) FIG. 2