Whole machine parachute parameter generation method and system based on bottom edge extension parachute

Abstract

The invention discloses a complete machine parachute parameter generation method and system based on a bottom edge extending parachute, and the method comprises the steps: obtaining the total weight of a complete machine system, a plurality of preset parachute opening heights, and a preset maximum vertical stable descent speed corresponding to each preset parachute opening height, and calculating the area and the maximum vertical stable descent speed of the complete machine parachute; the method comprises the following steps: acquiring a plurality of preset aircraft initial speeds, complete machine system weight information and atmospheric density of the minimum parachute opening height; generating a test maximum parachute opening dynamic load; performing limit analysis to obtain the maximum parachute opening dynamic load; calculating an initial dangerous section; and according to the dangerous section, calculating to obtain a radial maximum load and a latitudinal maximum load, generating canopy fabric parameters, parachute cord parameters and upper sling parameters, and outputting the area, the canopy fabric parameters, the parachute cord parameters and the upper sling parameters. Various parameters of the whole parachute can be generated, and design of the parachute is facilitated.

Description

Technical Field

[0001] This invention relates to the field of parachute technology, and in particular to a method, system, terminal, and storage medium for generating parameters of a complete parachute based on a bottom-edge extension parachute. Background Technology

[0002] With the gradual development of spacecraft, more and more aircraft are being used in fields such as manned transport and surveillance. During high-altitude flight, aircraft require safety protection to prevent sudden loss of control or other emergencies, thus ensuring the safety of personnel, cargo, and the aircraft itself. Currently, the last line of defense for aircraft safety typically consists of parachutes, which deploy in the event of a loss of control to slow the aircraft down and bring it to the ground at a lower speed, thereby protecting it.

[0003] However, currently, the selection of size and materials for parachutes on aircraft is usually based on the experience of designers who choose the appropriate size and materials used in the past. After that, a large number of experiments are conducted to test their safety. When the requirements are not met, it is necessary to design and test the size and materials of the parachute repeatedly, which leads to a waste of time and resources.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] The main objective of this invention is to provide a method, system, terminal, and computer-readable storage medium for generating parameters of a whole-aircraft parachute based on a bottom-edge extension parachute. This invention aims to solve the problem that in the prior art, the selection of size and materials for parachutes on aircraft is usually done by designers who directly select the appropriate size and materials based on experience. After that, a large number of experiments are conducted to test its safety. When the requirements are not met, it is necessary to design and test the size and materials of the parachute repeatedly, which leads to a waste of time and resources.

[0006] To achieve the above objectives, the present invention provides a method for generating whole-aircraft parachute parameters based on a bottom-edge extension parachute, the method comprising the following steps:

[0007] The total weight of the entire system and multiple preset parachute opening heights, as well as the preset maximum vertical descent speed corresponding to each preset parachute opening height, are obtained. The area of ​​the parachute is calculated. Based on the area, the total weight of the entire system, and the multiple preset parachute opening heights, the maximum vertical descent speed corresponding to each preset parachute opening height is obtained.

[0008] The system acquires multiple preset initial velocities of the aircraft, the weight of the entire system, and the atmospheric density at the minimum parachute opening altitude. Based on a preset algorithm, it generates the test maximum parachute opening dynamic load for each initial velocity of the aircraft at the minimum parachute opening altitude and performs limit analysis to obtain the maximum parachute opening dynamic load.

[0009] The initial critical section is calculated based on the maximum opening dynamic load and the preset drag coefficient. The initial critical section is then iterated based on the preset drag coefficient to obtain the critical section. The maximum radial load and the maximum latitudinal load are then calculated based on the critical section.

[0010] Generate umbrella fabric parameters based on the maximum radial load and the maximum weft load, obtain the preset number of paracords and upper straps, generate paracord parameters and upper strap parameters based on the maximum opening dynamic load, and output the area, umbrella fabric parameters, paracord parameters, and upper strap parameters.

[0011] Optionally, the step of obtaining the total weight of the entire system and multiple preset parachute deployment heights, as well as the preset maximum vertical descent velocity corresponding to each preset parachute deployment height, calculating the area of ​​the entire parachute, and obtaining the maximum vertical descent velocity corresponding to the multiple preset parachute deployment heights based on the area, the total weight of the entire system, and the multiple preset parachute deployment heights, specifically includes:

[0012] The total weight of the entire system and multiple preset parachute opening heights are obtained, as well as the preset maximum vertical descent velocity corresponding to each preset parachute opening height. The atmospheric density of the landing field at each preset parachute opening height is calculated based on each preset parachute opening height.

[0013] Based on the total weight of the entire system and multiple preset parachute opening heights, as well as the preset maximum vertical descent velocity corresponding to each preset parachute opening height and the atmospheric density of the landing site, the minimum main parachute drag characteristics corresponding to each preset parachute opening height are obtained. Based on all the minimum main parachute drag characteristics and drag coefficients, the area of ​​the entire parachute is generated.

[0014] Based on the area, the total weight of the entire system, multiple preset parachute deployment heights, and the atmospheric density of the landing field corresponding to each preset parachute deployment height, the maximum vertical descent velocity corresponding to each preset parachute deployment height is calculated.

[0015] Optionally, the step of acquiring multiple preset initial velocities of the aircraft, overall system weight information, and atmospheric density at the minimum parachute deployment altitude, and generating a test maximum parachute deployment dynamic load for each initial velocity at the minimum parachute deployment altitude based on a preset algorithm, specifically includes:

[0016] The system acquires multiple preset initial velocities of the aircraft, overall system weight information, and atmospheric density at the minimum parachute deployment altitude. The overall system weight information includes the payload weight and the parachute system weight.

[0017] Based on the preset algorithm, the test maximum parachute opening dynamic load is generated for each initial velocity of the aircraft at the minimum parachute opening height;

[0018] Specifically, the landing field atmospheric density is calculated based on the minimum parachute deployment altitude. The main parachute drag characteristics corresponding to the minimum deployment altitude are calculated based on the drag coefficient, the maximum vertical descent velocity, and the landing field atmospheric density corresponding to the minimum deployment altitude. The instantaneous system velocity expression is generated based on the main parachute drag characteristics corresponding to the minimum deployment altitude, the overall system weight information, and the current drag characteristic value. The maximum test deployment dynamic load expression is obtained based on the overall system weight information, the atmospheric density at the minimum deployment altitude, the instantaneous system velocity expression, and the main parachute drag characteristics corresponding to the minimum deployment altitude. Finally, the preset algorithm is generated based on the target algorithm and the maximum test deployment dynamic load expression.

[0019] Optionally, the step of performing limit analysis to obtain the maximum parachute opening dynamic load specifically includes:

[0020] Obtain the maximum value in the test maximum parachute opening dynamic load, as well as the corresponding initial parachute opening velocity, overall system weight information, and atmospheric density at the minimum parachute opening height;

[0021] Based on the preset limit analysis requirements, the initial parachute opening velocity and the weight of the entire system corresponding to the maximum test parachute opening dynamic load are multiplied by a weighting coefficient, and the maximum parachute opening dynamic load is generated based on the preset algorithm.

[0022] Optionally, the step of calculating the initial critical section based on the maximum opening dynamic load and a preset drag coefficient, and iterating the initial critical section according to the preset drag coefficient to obtain the critical section, and calculating the maximum radial load and the maximum latitudinal load based on the critical section, specifically includes:

[0023] The initial critical section is calculated based on the maximum parachute opening dynamic load, the preset initial velocity of the aircraft corresponding to the maximum parachute opening dynamic load, the atmospheric density at the minimum parachute opening altitude, and the preset drag coefficient.

[0024] The initial critical section is iterated based on a preset drag coefficient to obtain the critical section;

[0025] The maximum radial load and the maximum latitudinal load are calculated based on the critical section and the maximum opening dynamic load.

[0026] Optionally, the step of iterating the initial critical section according to a preset drag coefficient to obtain the critical section specifically includes:

[0027] A preset initial drag coefficient is used to calculate the first critical section based on the initial drag coefficient and the maximum parachute opening dynamic load. The first maximum parachute opening dynamic load is then calculated based on the preset drag coefficient and the first critical section.

[0028] The iteration error is calculated based on the preset drag coefficient and the initial drag coefficient. When the iteration error does not meet the preset requirements, the initial drag coefficient is updated based on the preset drag coefficient, the maximum parachute opening dynamic load and the first maximum parachute opening dynamic load. The initial dangerous section is iterated accordingly, and the preset requirements are re-evaluated.

[0029] If the iteration error does not meet the preset requirement after iteration, the iteration continues until the iteration error meets the preset requirement, and the first dangerous section corresponding to this iteration is taken as the dangerous section.

[0030] Optionally, the step of generating umbrella canopy fabric parameters based on the maximum radial load and the maximum weft load, obtaining a preset number of paracords and upper straps, generating paracord parameters and upper strap parameters based on the maximum opening dynamic load, and outputting the area, the umbrella canopy fabric parameters, the paracord parameters, and the upper strap parameters specifically includes:

[0031] The umbrella canopy fabric parameters are generated based on the preset fabric safety factor, the maximum radial load, and the maximum weft load.

[0032] Obtain the preset number of paracords and slings, and generate paracord parameters and sling parameters based on the maximum opening dynamic load and empirical formula;

[0033] Output the area, the umbrella fabric parameters, the paracord parameters, and the upper strap parameters.

[0034] Furthermore, to achieve the above objectives, the present invention also provides a whole-aircraft parachute parameter generation system based on a bottom-edge extension parachute, wherein the whole-aircraft parachute parameter generation system based on a bottom-edge extension parachute includes:

[0035] The area and velocity calculation module is used to obtain the total weight of the whole system and multiple preset parachute opening heights, as well as the preset maximum vertical descent velocity corresponding to each preset parachute opening height, calculate the area of ​​the whole parachute, and obtain the maximum vertical descent velocity corresponding to each preset parachute opening height based on the area, the total weight of the whole system and multiple preset parachute opening heights.

[0036] The maximum parachute opening dynamic load analysis module is used to obtain multiple preset initial velocities of aircraft, overall system weight information, and atmospheric density at the minimum parachute opening altitude. Based on a preset algorithm, it generates the test maximum parachute opening dynamic load for each initial velocity of aircraft at the minimum parachute opening altitude and performs limit analysis to obtain the maximum parachute opening dynamic load.

[0037] The iteration module is used to calculate the initial critical section based on the maximum opening dynamic load and the preset drag coefficient, and to iterate the initial critical section based on the preset drag coefficient to obtain the critical section. The maximum radial load and the maximum latitudinal load are calculated based on the critical section.

[0038] The output module is used to generate umbrella fabric parameters based on the maximum radial load and the maximum weft load, obtain the preset number of paracords and upper straps, generate paracord parameters and upper strap parameters based on the maximum opening dynamic load, and output the area, the umbrella fabric parameters, the paracord parameters, and the upper strap parameters.

[0039] Furthermore, to achieve the above objectives, the present invention also provides a terminal, wherein the terminal includes: a memory, a processor, and a whole-aircraft parachute parameter generation program based on a bottom-edge extension parachute stored in the memory and executable on the processor, wherein when the whole-aircraft parachute parameter generation program based on a bottom-edge extension parachute is executed by the processor, the steps of the whole-aircraft parachute parameter generation method based on a bottom-edge extension parachute as described above are implemented.

[0040] Furthermore, to achieve the above objectives, the present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a whole-aircraft parachute parameter generation program based on a bottom-edge extended parachute, and when the whole-aircraft parachute parameter generation program based on a bottom-edge extended parachute is executed by a processor, it implements the steps of the whole-aircraft parachute parameter generation method based on a bottom-edge extended parachute as described above.

[0041] In this invention, the total weight of the entire system and multiple preset parachute opening heights, as well as the preset maximum vertical descent velocity corresponding to each preset parachute opening height, are obtained. The area of ​​the entire parachute is calculated, and the maximum vertical descent velocity corresponding to each preset parachute opening height is obtained based on the area, the total weight of the entire system, and the multiple preset parachute opening heights. Multiple preset initial velocities of the aircraft, the weight information of the entire system, and the atmospheric density at the minimum parachute opening height are obtained. Based on a preset algorithm, the maximum test parachute opening dynamic load for each initial velocity of the aircraft at the minimum parachute opening height is generated, and limit analysis is performed to obtain the maximum parachute opening dynamic load. The initial critical section is calculated based on the maximum parachute opening dynamic load and a preset drag coefficient, and the initial critical section is iterated based on the preset drag coefficient to obtain the critical section. The maximum radial load and the maximum latitudinal load are calculated based on the critical section. The parachute canopy fabric parameters are generated based on the maximum radial load and the maximum latitudinal load. The preset number of parachute lines and upper harnesses are obtained, and the parachute line parameters and upper harness parameters are generated based on the maximum parachute opening dynamic load. The area, the parachute canopy fabric parameters, the parachute line parameters, and the upper harness parameters are output. This invention provides a method for generating parachute parameters for an entire aircraft based on a bottom-edge extension parachute. This method allows for the direct generation of relevant parameters during the parachute design process, avoiding inconsistent parachute quality caused by differences in the experience of different designers. Consequently, it avoids the waste of resources and time resulting from extensive testing and repetitive design. Attached Figure Description

[0042] Figure 1 This is a flowchart of a preferred embodiment of the method for generating whole-aircraft parachute parameters based on a bottom-edge extended parachute according to the present invention;

[0043] Figure 2 This is a schematic diagram of the whole parachute and the aircraft in the whole parachute parameter generation method based on the bottom edge extension parachute of the present invention.

[0044] Figure 3 This is a structural diagram of a preferred embodiment of the whole-aircraft parachute parameter generation system based on the bottom-edge extended parachute of the present invention;

[0045] Figure 4 This is a structural diagram of a preferred embodiment of the terminal of the present invention. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0047] With the gradual development of spacecraft, more and more aircraft are being used for manned, transportation, and monitoring purposes. During high-altitude flight, aircraft require safety protection to prevent sudden loss of control or other emergencies, thus ensuring the safety of personnel, cargo, and the aircraft itself. Currently, the last line of defense for aircraft safety typically consists of parachutes, which deploy in the event of loss of control to slow the aircraft down and bring it to the ground at a lower speed, thereby protecting it. However, the current selection of parachute size and materials for aircraft often relies on designers directly choosing sizes and using previously used materials based on experience. Extensive safety testing is then conducted, and when requirements are not met, repeated design and testing of parachute size and materials are necessary, leading to a waste of time and resources.

[0048] To address one or more of the above-mentioned problems, this application obtains the total weight of the entire system and multiple preset parachute opening heights, as well as the preset maximum vertical descent velocity corresponding to each preset parachute opening height. It calculates the area of ​​the entire parachute and, based on the area, the total weight of the entire system, and the multiple preset parachute opening heights, obtains the maximum vertical descent velocity corresponding to each preset parachute opening height. It also obtains multiple preset initial velocities of the aircraft, the weight information of the entire system, and the atmospheric density at the minimum parachute opening height. Based on a preset algorithm, it generates the test maximum parachute opening dynamic load for each initial velocity at the minimum parachute opening height and performs limit analysis to obtain the maximum parachute opening dynamic load. Based on the maximum parachute opening dynamic load and a preset drag coefficient, it calculates the initial critical section and iterates the initial critical section according to the preset drag coefficient to obtain the critical section. Based on the critical section, it calculates the maximum radial load and the maximum latitudinal load. Based on the maximum radial load and the maximum latitudinal load, it generates parachute fabric parameters, obtains the preset number of parachute lines and top straps, generates parachute line parameters and top strap parameters based on the maximum parachute opening dynamic load, and outputs the area, the parachute fabric parameters, the parachute line parameters, and the top strap parameters.

[0049] The preferred embodiment of the present invention describes a method for generating whole-aircraft parachute parameters based on a bottom-edge extension parachute, such as... Figure 1 As shown, the method for generating whole-aircraft parachute parameters based on a bottom-edge extension parachute includes the following steps:

[0050] Step S10: Obtain the total weight of the entire system and multiple preset parachute opening heights, as well as the preset maximum vertical descent speed corresponding to each preset parachute opening height. Calculate the area of ​​the entire parachute. Based on the area, the total weight of the entire system, and the multiple preset parachute opening heights, obtain the maximum vertical descent speed corresponding to each preset parachute opening height.

[0051] It should be noted that in this invention, the corresponding whole-aircraft parachute is a bottom-extendable parachute. When designing a bottom-extendable whole-aircraft parachute, the total weight of the whole system and the preset deployment height, as well as the preset maximum vertical descent speed corresponding to each preset deployment height, are obtained in advance. The total weight of the whole system includes the weight of the aircraft to which the whole-aircraft parachute is applied and the weight of the whole-aircraft parachute itself; the weight of the whole-aircraft parachute is preset. The preset heights are multiple different preset deployment heights, and each deployment height corresponds to a maximum vertical descent speed.

[0052] Further, the process of obtaining the total weight of the entire system and multiple preset parachute deployment heights, as well as the preset maximum vertical descent velocity corresponding to each preset parachute deployment height, calculating the area of ​​the entire parachute, and obtaining the maximum vertical descent velocity corresponding to the multiple preset parachute deployment heights based on the area, the total weight of the entire system, and the multiple preset parachute deployment heights, specifically includes:

[0053] The total weight of the entire system and multiple preset parachute opening heights are obtained, as well as the preset maximum vertical descent velocity corresponding to each preset parachute opening height. The atmospheric density of the landing field at each preset parachute opening height is calculated based on each preset parachute opening height.

[0054] Based on the total weight of the entire system and multiple preset parachute opening heights, as well as the preset maximum vertical descent velocity corresponding to each preset parachute opening height and the atmospheric density of the landing site, the minimum main parachute drag characteristics corresponding to each preset parachute opening height are obtained. Based on all the minimum main parachute drag characteristics and drag coefficients, the area of ​​the entire parachute is generated.

[0055] Based on the area, the total weight of the entire system, multiple preset parachute deployment heights, and the atmospheric density of the landing field corresponding to each preset parachute deployment height, the maximum vertical descent velocity corresponding to each preset parachute deployment height is calculated.

[0056] Specifically, in this invention, for each preset parachute opening height, the corresponding atmospheric density of the landing site is calculated using the following formula (1):

[0057]

[0058] Where h represents the preset parachute deployment altitude, ρ(h) represents the atmospheric density of the landing site corresponding to the preset parachute deployment altitude, and ρ sea This represents the standard atmospheric density at sea level, which is 1.225 kg / m³. 3 .

[0059] Based on the total weight of the entire system and the multiple preset parachute opening heights, as well as the preset maximum vertical descent velocity and the atmospheric density of the landing site corresponding to each preset parachute opening height, the minimum main parachute drag characteristic corresponding to each preset parachute opening height is obtained, and the specific calculation is shown in the following formula (2):

[0060]

[0061] Among them, (CA) main G represents the minimum main parachute drag characteristic. system ρ is the total weight of the entire system. land v represents the atmospheric density of the landing site corresponding to the current preset parachute deployment altitude. landing1 The preset maximum vertical descent velocity corresponds to the preset parachute opening height. The minimum main parachute drag characteristics at different preset parachute opening heights can be obtained through equation (2).

[0062] In this invention, the whole-aircraft parachute is designed based on a bottom-edge extension parachute. Therefore, a corresponding drag coefficient is set based on empirical data. The minimum main parachute drag characteristic with the largest value is selected from all preset opening heights, and this value is divided by the drag coefficient and rounded to obtain the corresponding area of ​​the whole-aircraft parachute, i.e., the nominal area of ​​the main parachute. The nominal diameter can be obtained from the nominal area. Furthermore, this bottom-edge extension parachute structure adds a ring-shaped extension to the circumference of the bottom edge of a circular parachute. When the canopy sways, the bottom edge extension generates a restoring torque, thus reducing the average sway angle and making its stability far superior to that of a conventional flat circular parachute.

[0063] In this invention, after the area is calculated, the maximum vertical descent velocity corresponding to each preset parachute opening height can be calculated based on the area, the total weight of the entire system, multiple preset parachute opening heights, and the atmospheric density of the landing field corresponding to each preset parachute opening height. The specific calculation is shown in the following formula (3):

[0064]

[0065] Among them, v landing This indicates the maximum vertical descent speed corresponding to each preset parachute opening height.

[0066] Atmospheric density varies at different altitudes; therefore, the landing altitude and mass of the aircraft jointly affect the system's descent rate. In this invention, different maximum vertical descent velocities can be calculated corresponding to different parachute deployment altitudes.

[0067] Step S20: Obtain multiple preset initial velocities of the aircraft, overall system weight information, and atmospheric density at the minimum parachute opening altitude. Based on a preset algorithm, generate the test maximum parachute opening dynamic load for each initial velocity of the aircraft at the minimum parachute opening altitude, and perform limit analysis to obtain the maximum parachute opening dynamic load.

[0068] It should be noted that in this invention, when generating the parachute parameters of the whole aircraft, the maximum test parachute opening dynamic load of the aircraft at different initial velocities at the minimum parachute opening height is generated, and the maximum test parachute opening dynamic load with the largest value is selected for ultimate load to obtain the corresponding maximum parachute opening dynamic load.

[0069] Furthermore, the acquisition of multiple preset initial velocities of the aircraft, overall system weight information, and atmospheric density at the minimum parachute deployment altitude, and the generation of the maximum test parachute deployment dynamic load for each initial velocity at the minimum parachute deployment altitude based on a preset algorithm, specifically includes:

[0070] The system acquires multiple preset initial velocities of the aircraft, overall system weight information, and atmospheric density at the minimum parachute deployment altitude. The overall system weight information includes the payload weight and the parachute system weight.

[0071] Based on the preset algorithm, the test maximum parachute opening dynamic load is generated for each initial velocity of the aircraft at the minimum parachute opening height;

[0072] Specifically, the landing field atmospheric density is calculated based on the minimum parachute deployment altitude. The main parachute drag characteristics corresponding to the minimum deployment altitude are calculated based on the drag coefficient, the maximum vertical descent velocity, and the landing field atmospheric density corresponding to the minimum deployment altitude. The instantaneous system velocity expression is generated based on the main parachute drag characteristics corresponding to the minimum deployment altitude, the overall system weight information, and the current drag characteristic value. The maximum test deployment dynamic load expression is obtained based on the overall system weight information, the atmospheric density at the minimum deployment altitude, the instantaneous system velocity expression, and the main parachute drag characteristics corresponding to the minimum deployment altitude. Finally, the preset algorithm is generated based on the target algorithm and the maximum test deployment dynamic load expression.

[0073] It should be noted that in this invention, the multiple preset initial flight velocities include the aircraft's stationary speed, maximum speed, and multiple preset speeds between the stationary speed and the maximum speed; the weight of the entire system includes the load weight, the parachute system weight, and the additional mass, wherein the load weight is the weight of the aircraft, the parachute system weight is the weight of the entire parachute, and the additional mass is the atmospheric mass affected by the parachute canopy drag; the atmospheric density corresponding to the minimum parachute opening height can be calculated by formula (1).

[0074] Specifically, in this invention, the designed and generated whole-aircraft parachute is ejected by an ejection tube during use. The ejection tube can straighten the corresponding main parachute within 1 second, so this process is considered as a free fall process. For the parachute opening process, the height loss caused by the opening of the parachute is expressed as the following formula (4):

[0075]

[0076] Among them, H 损失 Let t represent the lost altitude, g represent the time, and g represent the gravitational acceleration. The corresponding parachute opening velocity and trajectory angle are expressed as equations (5) and (6) below:

[0077]

[0078] Among them, v L v0 represents the parachute opening speed, v0 represents the preset initial velocity of the aircraft, i.e., the initial horizontal velocity of the aircraft, and θ represents the trajectory angle.

[0079] For the inflation phase of the parachute, the instantaneous velocity can be expressed as equation (7):

[0080]

[0081] m w For the load mass, m s For the quality of the parachute system, m f For the added mass, θ is the angle between the object umbrella's motion and the horizontal plane at the current moment, i.e., the trajectory angle (since the object umbrella usually has a downward velocity component, θ is often negative); ρ is the atmospheric density at the current altitude, which can be obtained through equation (1); and (CA) is the characteristic value of the umbrella canopy drag at the current moment.

[0082] Among them, for the added mass m f We obtain the following from equation (8):

[0083] m f =ρk f (CA) 3 / 2 (8)

[0084] k f For the additional quality coefficient, and

[0085] The angle θ between the umbrella's motion and the horizontal plane can be expressed as:

[0086]

[0087] Differentiating the additional mass function with respect to time yields its rate of change over time, which is obtained through the following equation (10):

[0088]

[0089] The characteristic value of the parachute canopy drag at the current moment can be represented in two parts, as shown in the following equation (11):

[0090]

[0091] Among them, (CA) s The main parachute drag characteristic, i.e., the main parachute drag characteristic corresponding to the minimum opening height, can be obtained by equation (2) for the main parachute drag characteristic corresponding to the current opening height; t f The time it takes for the main umbrella to open, and coefficient λ f Values ​​preset for the user.

[0092] Correspondingly, in this invention, by substituting the main parachute drag characteristics corresponding to the minimum parachute opening height, the system weight information, and the current drag characteristic value into equation (7), the instantaneous motion rate of the system can be obtained; based on the system weight information, the atmospheric density at the minimum parachute opening height, the instantaneous motion rate of the system, and the main parachute drag characteristics corresponding to the minimum parachute opening height, the maximum test parachute opening dynamic load can be obtained, as shown in equation (12):

[0093]

[0094] Substituting equations (7) to (11) into equation (12) yields the expression for the maximum parachute opening dynamic load at different initial velocities.

[0095] Using the MATLAB ode23 algorithm and the target algorithm, according to equation (12), the corresponding preset algorithm can be obtained. The preset algorithm can be used to calculate the change diagram of the parachute opening dynamic load. Furthermore, in this invention, the change diagrams of speed and height are added to the preset algorithm, wherein the corresponding speed change formula is equation (7), and the height change formula is expressed as equation (13):

[0096]

[0097] By using the corresponding preset algorithm, the maximum test dynamic load of parachute opening can be obtained at the minimum parachute opening height for different initial opening velocities.

[0098] Furthermore, the limit analysis to obtain the maximum parachute opening dynamic load specifically includes:

[0099] Obtain the maximum value in the test maximum parachute opening dynamic load, as well as the corresponding initial parachute opening velocity, overall system weight information, and atmospheric density at the minimum parachute opening height;

[0100] Based on the preset limit analysis requirements, the initial parachute opening velocity and the weight of the entire system corresponding to the maximum test parachute opening dynamic load are multiplied by a weighting coefficient, and the maximum parachute opening dynamic load is generated based on the preset algorithm.

[0101] Specifically, during the limit analysis, the maximum value among all tested maximum parachute opening dynamic loads is obtained, along with the corresponding initial parachute opening velocity, overall system weight information, and atmospheric density at the minimum parachute opening height. This set of data is then used to perform the corresponding limit analysis.

[0102] Based on the pre-set requirements of the limit analysis, the initial parachute opening velocity and the weight information of the entire system corresponding to the maximum test parachute opening dynamic load are multiplied by a weighting factor. The requirement of the limit analysis is the limit load safety factor, and the weighting factor includes the weight weighting factor. Limit load safety factor = (total system weight information × weight weighting factor) × (initial parachute opening velocity × velocity weighting factor). 2 When setting weighting coefficients according to the ultimate load safety factor, the set weighting coefficients must satisfy: weight weighting coefficient × speed weighting coefficient × speed weighting coefficient ≥ ultimate load safety factor. Preferably, in one embodiment of the present invention, after multiplication, the initial parachute opening velocity, the overall system weight information, and the atmospheric density at the minimum parachute opening height corresponding to the maximum test parachute opening dynamic load are multiplied by the corresponding weighting coefficients. For the expanded case, the maximum test parachute opening dynamic load at this time is calculated and used as the maximum parachute opening dynamic load.

[0103] Step S30: Calculate the initial critical section based on the maximum opening dynamic load and the preset drag coefficient, and iterate the initial critical section based on the preset drag coefficient to obtain the critical section. Calculate the maximum radial load and the maximum latitudinal load based on the critical section.

[0104] Specifically, the maximum opening dynamic load is obtained, which is used to calculate the critical section, and the corresponding maximum radial load and maximum latitudinal load are generated through the critical section.

[0105] Further, the step of calculating the initial critical section based on the maximum opening dynamic load and the preset drag coefficient, and iterating the initial critical section according to the preset drag coefficient to obtain the critical section, and calculating the maximum radial load and the maximum latitudinal load based on the critical section, specifically includes:

[0106] The initial critical section is calculated based on the maximum parachute opening dynamic load, the preset initial velocity of the aircraft corresponding to the maximum parachute opening dynamic load, the atmospheric density at the minimum parachute opening altitude, and the preset drag coefficient.

[0107] The initial critical section is iterated based on a preset drag coefficient to obtain the critical section;

[0108] The maximum radial load and the maximum latitudinal load are calculated based on the critical section and the maximum opening dynamic load.

[0109] Specifically, in this invention, the initial critical section is calculated based on the maximum parachute opening dynamic load, the preset initial velocity of the aircraft corresponding to the maximum parachute opening dynamic load, the atmospheric density at the minimum parachute opening altitude, and the preset drag coefficient, as shown in Equation (14):

[0110]

[0111] Among them, A w Indicates the initial critical section, C ' D The initial resistance coefficient is half of the preset resistance coefficient, and C ' D =C D / 2, F kmax This indicates the maximum dynamic load when the parachute opens.

[0112] The initial critical section is iterated to obtain the critical section, and the corresponding radial maximum load and latitudinal maximum load are obtained based on the critical section.

[0113] Furthermore, the step of iterating the initial critical section according to a preset drag coefficient to obtain the critical section specifically includes:

[0114] A preset initial drag coefficient is used to calculate the first critical section based on the initial drag coefficient and the maximum parachute opening dynamic load. The first maximum parachute opening dynamic load is then calculated based on the preset drag coefficient and the first critical section.

[0115] The iteration error is calculated based on the preset drag coefficient and the initial drag coefficient. When the iteration error does not meet the preset requirements, the initial drag coefficient is updated based on the preset drag coefficient, the maximum parachute opening dynamic load and the first maximum parachute opening dynamic load. The initial dangerous section is iterated accordingly, and the preset requirements are re-evaluated.

[0116] If the iteration error does not meet the preset requirement after iteration, the iteration continues until the iteration error meets the preset requirement, and the first dangerous section corresponding to this iteration is taken as the dangerous section.

[0117] Specifically, in this invention, the initial drag coefficient is preset to be half of the preset drag coefficient. Then, for the calculation of the first maximum opening dynamic load, it is specifically as shown in equation (15):

[0118]

[0119] in, Indicates the first maximum parachute opening dynamic load, vz Let ρ0 be the steady-state descent rate at the landing site altitude, and ρ0 be the atmospheric density at sea level, i.e., ρ sea k is a constant coefficient, preset by the user; A0 is the nominal area of ​​the main parachute when fully open, and its corresponding size is the size of the current first dangerous section; Δ is the relative density of air, and ρ H This is the atmospheric density corresponding to this altitude.

[0120] After calculating the first maximum parachute opening dynamic load, the initial drag coefficient C is updated accordingly. ' D The update method is shown in equation (16) below:

[0121]

[0122] After updating the initial drag coefficient, determine whether the preset requirement is met, where the preset requirement is C. ' D With C D The error, i.e. (C) D -C ' D ) / C D The value of is continuously iterated when the error is not within the preset threshold, that is, the formula (14) to formula (16) are repeated; when the error is within the preset threshold, the first dangerous section is recalculated based on the initial resistance coefficient of this time, and the result is taken as the dangerous section A. w1 .

[0123] Once the critical section is obtained, the corresponding maximum radial load and maximum lateral load are expressed as follows:

[0124]

[0125] Where, σ jx For the maximum radial load, σ wx This represents the maximum load in the latitudinal direction.

[0126] Step S40: Generate umbrella fabric parameters based on the maximum radial load and the maximum weft load, obtain the preset number of paracords and upper straps, generate paracord parameters and upper strap parameters based on the maximum opening dynamic load, and output the area, umbrella fabric parameters, paracord parameters, and upper strap parameters.

[0127] Specifically, such as Figure 2 As shown, the aircraft is a multi-rotor manned aircraft or a light sport aircraft. The corresponding whole-aircraft parachute includes parachute lines and upper slings. Various parameters of the whole-aircraft parachute are generated by calculating the maximum radial load and the maximum latitudinal load.

[0128] Further, the process of generating umbrella canopy fabric parameters based on the maximum radial load and the maximum weft load, obtaining preset quantities of paracords and upper straps, generating paracord parameters and upper strap parameters based on the maximum opening dynamic load, and outputting the area, the umbrella canopy fabric parameters, the paracord parameters, and the upper strap parameters specifically includes:

[0129] The umbrella canopy fabric parameters are generated based on the preset fabric safety factor, the maximum radial load, and the maximum weft load.

[0130] Obtain the preset number of paracords and slings, and generate paracord parameters and sling parameters based on the maximum opening dynamic load and empirical formula;

[0131] Output the area, the umbrella fabric parameters, the paracord parameters, and the upper strap parameters.

[0132] Specifically, the preset fabric safety factor is obtained, and multiplied by the corresponding maximum radial load and maximum weft load to obtain the warp tensile strength and weft tensile strength. After rounding up, these are the umbrella canopy fabric parameters.

[0133] Then, based on the number of paracords and slings, empirical formulas are used to generate the paracord parameters and sling parameters. The empirical formulas are expressed as follows:

[0134]

[0135] Among them, T sh The maximum load on the paracord, T ztd n represents the maximum load on the upper sling. sh n represents the number of paracords. ztd Indicates the number of slings.

[0136] Calculate the tensile strength of the paracord and sling based on their safety factors, i.e., the paracord safety factor and T. sh Multiply the maximum load of the paracords by the maximum load of the slings, and multiply the safety factor of the slings by the maximum load of the slings to obtain the paracord parameters and the sling parameters.

[0137] The corresponding area, the parameters of the umbrella canopy fabric, the parameters of the paracords, and the parameters of the upper straps will be output for designers to refer to.

[0138] This invention obtains the total weight of the entire system and multiple preset parachute opening heights, as well as the preset maximum vertical descent velocity corresponding to each preset parachute opening height. It calculates the area of ​​the entire parachute and, based on the area, total weight, and multiple preset parachute opening heights, obtains the maximum vertical descent velocity corresponding to each preset parachute opening height. It also obtains multiple preset initial velocities of the aircraft, the weight information of the entire system, and the atmospheric density at the minimum parachute opening height. Based on a preset algorithm, it generates the test maximum parachute opening dynamic load for each initial velocity at the minimum parachute opening height and performs limit analysis to obtain the maximum parachute opening dynamic load. Based on the maximum parachute opening dynamic load and a preset drag coefficient, it calculates the initial critical section and iterates the initial critical section according to the preset drag coefficient to obtain the critical section. Based on the critical section, it calculates the maximum radial load and the maximum latitudinal load. Based on the maximum radial load and the maximum latitudinal load, it generates parachute fabric parameters, obtains the preset number of parachute lines and top straps, generates parachute line parameters and top strap parameters based on the maximum parachute opening dynamic load, and outputs the area, the parachute fabric parameters, the parachute line parameters, and the top strap parameters. This invention provides a method for generating parachute parameters for an entire aircraft based on a bottom-edge extension parachute. This method allows for the direct generation of relevant parameters during the parachute design process, avoiding inconsistent parachute quality caused by differences in the experience of different designers. Consequently, it avoids the waste of resources and time resulting from extensive testing and repetitive design.

[0139] Furthermore, such as Figure 3 As shown, based on the above-described method for generating whole-aircraft parachute parameters based on a bottom-edge extension parachute, the present invention also provides a system for generating whole-aircraft parachute parameters based on a bottom-edge extension parachute, wherein the system for generating whole-aircraft parachute parameters based on a bottom-edge extension parachute includes:

[0140] The area and speed calculation module 31 is used to obtain the total weight of the whole system and multiple preset parachute opening heights, as well as the preset maximum vertical descent speed corresponding to each preset parachute opening height, calculate the area of ​​the whole parachute, and obtain the maximum vertical descent speed corresponding to each preset parachute opening height based on the area, the total weight of the whole system and multiple preset parachute opening heights.

[0141] The maximum parachute opening dynamic load analysis module 32 is used to acquire multiple preset initial velocities of aircraft, weight information of the whole system, and atmospheric density at the minimum parachute opening altitude. Based on a preset algorithm, it generates the test maximum parachute opening dynamic load for each initial velocity of aircraft at the minimum parachute opening altitude and performs limit analysis to obtain the maximum parachute opening dynamic load.

[0142] The iteration module 33 is used to calculate the initial critical section based on the maximum opening dynamic load and the preset drag coefficient, and to iterate the initial critical section based on the preset drag coefficient to obtain the critical section. The maximum radial load and the maximum latitudinal load are calculated based on the critical section.

[0143] Output module 34 is used to generate umbrella fabric parameters based on the maximum radial load and the maximum weft load, obtain the preset number of paracords and upper straps, generate paracord parameters and upper strap parameters based on the maximum opening dynamic load, and output the area, the umbrella fabric parameters, the paracord parameters and the upper strap parameters.

[0144] Furthermore, such as Figure 4 As shown, based on the above-mentioned method and system for generating parachute parameters for the entire aircraft based on the bottom-edge extension parachute, the present invention also provides a terminal, which includes a processor 10, a memory 20 and a display 30. Figure 4 Only some of the terminal components are shown; however, it should be understood that it is not required to implement all of the components shown, and more or fewer components may be implemented instead.

[0145] In some embodiments, the memory 20 may be an internal storage unit of the terminal, such as a hard disk or memory. In other embodiments, the memory 20 may be an external storage device of the terminal, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc. Further, the memory 20 may include both internal and external storage devices. The memory 20 is used to store application software and various types of data installed on the terminal, such as the program code installed on the terminal. The memory 20 can also be used to temporarily store data that has been output or will be output. In one embodiment, the memory 20 stores a parachute parameter generation program 40 based on a bottom-edge extender parachute. This parachute parameter generation program 40 can be executed by the processor 10 to implement the parachute parameter generation method based on a bottom-edge extender parachute in this application.

[0146] In some embodiments, the processor 10 may be a central processing unit (CPU), a microprocessor, or other data processing chip, used to run program code stored in the memory 20 or process data, such as executing the whole parachute parameter generation method based on the bottom edge extension parachute.

[0147] In some embodiments, the display 30 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen. The display 30 is used to display information on the terminal and to display a visual user interface. The components 10-30 of the terminal communicate with each other via a system bus.

[0148] In one embodiment, when the processor 10 executes the whole parachute parameter generation program 40 based on the bottom-edge extension parachute in the memory 20, the steps in the whole parachute parameter generation method based on the bottom-edge extension parachute described above are implemented.

[0149] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a whole-aircraft parachute parameter generation program based on a bottom-edge extended parachute, and when the whole-aircraft parachute parameter generation program based on a bottom-edge extended parachute is executed by a processor, it implements the steps of the whole-aircraft parachute parameter generation method based on a bottom-edge extended parachute as described below.

[0150] The method for generating whole-aircraft parachute parameters based on a bottom-edge extended parachute includes:

[0151] The total weight of the entire system and multiple preset parachute opening heights, as well as the preset maximum vertical descent speed corresponding to each preset parachute opening height, are obtained. The area of ​​the parachute is calculated. Based on the area, the total weight of the entire system, and the multiple preset parachute opening heights, the maximum vertical descent speed corresponding to each preset parachute opening height is obtained.

[0152] The system acquires multiple preset initial velocities of the aircraft, the weight of the entire system, and the atmospheric density at the minimum parachute opening altitude. Based on a preset algorithm, it generates the test maximum parachute opening dynamic load for each initial velocity of the aircraft at the minimum parachute opening altitude and performs limit analysis to obtain the maximum parachute opening dynamic load.

[0153] The initial critical section is calculated based on the maximum opening dynamic load and the preset drag coefficient. The initial critical section is then iterated based on the preset drag coefficient to obtain the critical section. The maximum radial load and the maximum latitudinal load are then calculated based on the critical section.

[0154] Generate umbrella fabric parameters based on the maximum radial load and the maximum weft load, obtain the preset number of paracords and upper straps, generate paracord parameters and upper strap parameters based on the maximum opening dynamic load, and output the area, umbrella fabric parameters, paracord parameters, and upper strap parameters.

[0155] The process of obtaining the total weight of the entire system and multiple preset parachute deployment heights, as well as the preset maximum vertical descent velocity corresponding to each preset parachute deployment height, calculating the area of ​​the entire parachute, and obtaining the maximum vertical descent velocity corresponding to the multiple preset parachute deployment heights based on the area, the total weight of the entire system, and the multiple preset parachute deployment heights, specifically includes:

[0156] The total weight of the entire system and multiple preset parachute opening heights are obtained, as well as the preset maximum vertical descent velocity corresponding to each preset parachute opening height. The atmospheric density of the landing field at each preset parachute opening height is calculated based on each preset parachute opening height.

[0157] Based on the total weight of the entire system and multiple preset parachute opening heights, as well as the preset maximum vertical descent velocity corresponding to each preset parachute opening height and the atmospheric density of the landing site, the minimum main parachute drag characteristics corresponding to each preset parachute opening height are obtained. Based on all the minimum main parachute drag characteristics and drag coefficients, the area of ​​the entire parachute is generated.

[0158] Based on the area, the total weight of the entire system, multiple preset parachute deployment heights, and the atmospheric density of the landing field corresponding to each preset parachute deployment height, the maximum vertical descent velocity corresponding to each preset parachute deployment height is calculated.

[0159] The process of acquiring multiple preset initial velocities of the aircraft, overall system weight information, and atmospheric density at the minimum parachute deployment altitude, and generating the test maximum parachute deployment dynamic load for each initial velocity at the minimum parachute deployment altitude based on a preset algorithm, specifically includes:

[0160] The system acquires multiple preset initial velocities of the aircraft, overall system weight information, and atmospheric density at the minimum parachute deployment altitude. The overall system weight information includes the payload weight and the parachute system weight.

[0161] Based on the preset algorithm, the test maximum parachute opening dynamic load is generated for each initial velocity of the aircraft at the minimum parachute opening height;

[0162] Specifically, the landing field atmospheric density is calculated based on the minimum parachute deployment altitude. The main parachute drag characteristics corresponding to the minimum deployment altitude are calculated based on the drag coefficient, the maximum vertical descent velocity, and the landing field atmospheric density corresponding to the minimum deployment altitude. The instantaneous system velocity expression is generated based on the main parachute drag characteristics corresponding to the minimum deployment altitude, the overall system weight information, and the current drag characteristic value. The maximum test deployment dynamic load expression is obtained based on the overall system weight information, the atmospheric density at the minimum deployment altitude, the instantaneous system velocity expression, and the main parachute drag characteristics corresponding to the minimum deployment altitude. Finally, the preset algorithm is generated based on the target algorithm and the maximum test deployment dynamic load expression.

[0163] The process of performing limit analysis to obtain the maximum parachute opening dynamic load specifically includes:

[0164] Obtain the maximum value in the test maximum parachute opening dynamic load, as well as the corresponding initial parachute opening velocity, overall system weight information, and atmospheric density at the minimum parachute opening height;

[0165] Based on the preset limit analysis requirements, the initial parachute opening velocity and the weight of the entire system corresponding to the maximum test parachute opening dynamic load are multiplied by a weighting coefficient, and the maximum parachute opening dynamic load is generated based on the preset algorithm.

[0166] Specifically, the process of calculating the initial critical section based on the maximum opening dynamic load and a preset drag coefficient, iterating the initial critical section according to the preset drag coefficient to obtain the critical section, and calculating the maximum radial load and the maximum latitudinal load based on the critical section includes:

[0167] The initial critical section is calculated based on the maximum parachute opening dynamic load, the preset initial velocity of the aircraft corresponding to the maximum parachute opening dynamic load, the atmospheric density at the minimum parachute opening altitude, and the preset drag coefficient.

[0168] The initial critical section is iterated based on a preset drag coefficient to obtain the critical section;

[0169] The maximum radial load and the maximum latitudinal load are calculated based on the critical section and the maximum opening dynamic load.

[0170] Specifically, the step of iterating the initial critical section according to a preset drag coefficient to obtain the critical section includes:

[0171] A preset initial drag coefficient is used to calculate the first critical section based on the initial drag coefficient and the maximum parachute opening dynamic load. The first maximum parachute opening dynamic load is then calculated based on the preset drag coefficient and the first critical section.

[0172] The iteration error is calculated based on the preset drag coefficient and the initial drag coefficient. When the iteration error does not meet the preset requirements, the initial drag coefficient is updated based on the preset drag coefficient, the maximum parachute opening dynamic load and the first maximum parachute opening dynamic load. The initial dangerous section is iterated accordingly, and the preset requirements are re-evaluated.

[0173] If the iteration error does not meet the preset requirement after iteration, the iteration continues until the iteration error meets the preset requirement, and the first dangerous section corresponding to this iteration is taken as the dangerous section.

[0174] Specifically, the process of generating umbrella canopy fabric parameters based on the maximum radial load and the maximum weft load, obtaining preset quantities of paracords and upper straps, generating paracord parameters and upper strap parameters based on the maximum opening dynamic load, and outputting the area, umbrella canopy fabric parameters, paracord parameters, and upper strap parameters includes:

[0175] The umbrella canopy fabric parameters are generated based on the preset fabric safety factor, the maximum radial load, and the maximum weft load.

[0176] Obtain the preset number of paracords and slings, and generate paracord parameters and sling parameters based on the maximum opening dynamic load and empirical formula;

[0177] Output the area, the umbrella fabric parameters, the paracord parameters, and the upper strap parameters.

[0178] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal that includes that element.

[0179] Of course, those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware (such as a processor, controller, etc.). The program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The computer-readable storage medium can be a memory, magnetic disk, optical disk, etc.

[0180] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for generating whole-aircraft parachute parameters based on a bottom-edge extension parachute, characterized in that, The method for generating whole-aircraft parachute parameters based on a bottom-edge extended parachute includes: The total weight of the entire system and multiple preset parachute opening heights, as well as the preset maximum vertical descent speed corresponding to each preset parachute opening height, are obtained. The area of ​​the parachute is calculated. Based on the area, the total weight of the entire system, and the multiple preset parachute opening heights, the maximum vertical descent speed corresponding to each preset parachute opening height is obtained. The system acquires multiple preset initial velocities of the aircraft, the weight of the entire system, and the atmospheric density at the minimum parachute opening altitude. Based on a preset algorithm, it generates the test maximum parachute opening dynamic load for each initial velocity of the aircraft at the minimum parachute opening altitude and performs limit analysis to obtain the maximum parachute opening dynamic load. The initial critical section is calculated based on the maximum opening dynamic load and the preset drag coefficient. The initial critical section is then iterated based on the preset drag coefficient to obtain the critical section. The maximum radial load and the maximum latitudinal load are then calculated based on the critical section. Generate umbrella fabric parameters based on the maximum radial load and the maximum weft load, obtain the preset number of paracords and upper straps, generate paracord parameters and upper strap parameters based on the maximum opening dynamic load, and output the area, umbrella fabric parameters, paracord parameters, and upper strap parameters.

2. The method for generating whole-aircraft parachute parameters based on a bottom-edge extended parachute according to claim 1, characterized in that, The process of obtaining the total weight of the entire system and multiple preset parachute deployment heights, as well as the preset maximum vertical descent velocity corresponding to each preset parachute deployment height, calculating the area of ​​the entire parachute, and obtaining the maximum vertical descent velocity corresponding to the multiple preset parachute deployment heights based on the area, the total weight of the entire system, and the multiple preset parachute deployment heights, specifically includes: The total weight of the entire system and multiple preset parachute opening heights are obtained, as well as the preset maximum vertical descent velocity corresponding to each preset parachute opening height. The atmospheric density of the landing field at each preset parachute opening height is calculated based on each preset parachute opening height. Based on the total weight of the entire system and multiple preset parachute opening heights, as well as the preset maximum vertical descent velocity corresponding to each preset parachute opening height and the atmospheric density of the landing site, the minimum main parachute drag characteristics corresponding to each preset parachute opening height are obtained. Based on all the minimum main parachute drag characteristics and drag coefficients, the area of ​​the entire parachute is generated. Based on the area, the total weight of the entire system, multiple preset parachute deployment heights, and the atmospheric density of the landing field corresponding to each preset parachute deployment height, the maximum vertical descent velocity corresponding to each preset parachute deployment height is calculated.

3. The method for generating whole-aircraft parachute parameters based on a bottom-edge extended parachute according to claim 1, characterized in that, The process involves acquiring multiple preset initial velocities of the aircraft, overall system weight information, and atmospheric density at the minimum parachute deployment altitude. Based on a preset algorithm, a test maximum parachute deployment dynamic load is generated for each initial velocity of the aircraft at the minimum parachute deployment altitude. Specifically, this includes: The system acquires multiple preset initial velocities of the aircraft, overall system weight information, and atmospheric density at the minimum parachute deployment altitude. The overall system weight information includes the payload weight and the parachute system weight. Based on the preset algorithm, the test maximum parachute opening dynamic load is generated for each initial velocity of the aircraft at the minimum parachute opening height; Specifically, the landing field atmospheric density is calculated based on the minimum parachute deployment altitude. The main parachute drag characteristics corresponding to the minimum deployment altitude are calculated based on the drag coefficient, the maximum vertical descent velocity, and the landing field atmospheric density corresponding to the minimum deployment altitude. The instantaneous system velocity expression is generated based on the main parachute drag characteristics corresponding to the minimum deployment altitude, the overall system weight information, and the current drag characteristic value. The maximum test deployment dynamic load expression is obtained based on the overall system weight information, the atmospheric density at the minimum deployment altitude, the instantaneous system velocity expression, and the main parachute drag characteristics corresponding to the minimum deployment altitude. Finally, the preset algorithm is generated based on the target algorithm and the maximum test deployment dynamic load expression.

4. The method for generating whole-aircraft parachute parameters based on a bottom-edge extended parachute according to claim 1, characterized in that, The limit analysis is performed to obtain the maximum parachute opening dynamic load, specifically including: Obtain the maximum value in the test maximum parachute opening dynamic load, as well as the corresponding initial parachute opening velocity, overall system weight information, and atmospheric density at the minimum parachute opening height; Based on the preset limit analysis requirements, the initial parachute opening velocity and the weight of the entire system corresponding to the maximum test parachute opening dynamic load are multiplied by a weighting coefficient, and the maximum parachute opening dynamic load is generated based on the preset algorithm.

5. The method for generating whole-aircraft parachute parameters based on a bottom-edge extended parachute according to claim 1, characterized in that, The process of calculating the initial critical section based on the maximum opening dynamic load and a preset drag coefficient, and iterating the initial critical section according to the preset drag coefficient to obtain the critical section, and calculating the maximum radial load and the maximum latitudinal load based on the critical section, specifically includes: The initial critical section is calculated based on the maximum parachute opening dynamic load, the preset initial velocity of the aircraft corresponding to the maximum parachute opening dynamic load, the atmospheric density at the minimum parachute opening altitude, and the preset drag coefficient. The initial critical section is iterated based on a preset drag coefficient to obtain the critical section; The maximum radial load and the maximum latitudinal load are calculated based on the critical section and the maximum opening dynamic load.

6. The method for generating whole-aircraft parachute parameters based on a bottom-edge extended parachute according to claim 5, characterized in that, The step of iterating the initial critical section according to a preset drag coefficient to obtain the critical section specifically includes: A preset initial drag coefficient is used to calculate the first critical section based on the initial drag coefficient and the maximum parachute opening dynamic load. The first maximum parachute opening dynamic load is then calculated based on the preset drag coefficient and the first critical section. The iteration error is calculated based on the preset drag coefficient and the initial drag coefficient. When the iteration error does not meet the preset requirements, the initial drag coefficient is updated based on the preset drag coefficient, the maximum parachute opening dynamic load and the first maximum parachute opening dynamic load. The initial dangerous section is iterated accordingly, and the preset requirements are re-evaluated. If the iteration error does not meet the preset requirement after iteration, the iteration continues until the iteration error meets the preset requirement, and the first dangerous section corresponding to this iteration is taken as the dangerous section.

7. The method for generating whole-aircraft parachute parameters based on a bottom-edge extended parachute according to claim 1, characterized in that, The process of generating umbrella fabric parameters based on the maximum radial load and the maximum weft load, obtaining preset quantities of paracords and upper straps, generating paracord parameters and upper strap parameters based on the maximum opening dynamic load, and outputting the area, umbrella fabric parameters, paracord parameters, and upper strap parameters specifically includes: The umbrella canopy fabric parameters are generated based on the preset fabric safety factor, the maximum radial load, and the maximum weft load. Obtain the preset number of paracords and slings, and generate paracord parameters and sling parameters based on the maximum opening dynamic load and empirical formula; Output the area, the umbrella fabric parameters, the paracord parameters, and the upper strap parameters.

8. A whole-aircraft parachute parameter generation system based on a bottom-edge extension parachute, characterized in that, The whole-aircraft parachute parameter generation system based on the bottom-edge extension parachute includes: The area and velocity calculation module is used to obtain the total weight of the whole system and multiple preset parachute opening heights, as well as the preset maximum vertical descent velocity corresponding to each preset parachute opening height, calculate the area of ​​the whole parachute, and obtain the maximum vertical descent velocity corresponding to each preset parachute opening height based on the area, the total weight of the whole system and multiple preset parachute opening heights. The maximum parachute opening dynamic load analysis module is used to obtain multiple preset initial velocities of aircraft, overall system weight information, and atmospheric density at the minimum parachute opening altitude. Based on a preset algorithm, it generates the test maximum parachute opening dynamic load for each initial velocity of aircraft at the minimum parachute opening altitude and performs limit analysis to obtain the maximum parachute opening dynamic load. The iteration module is used to calculate the initial critical section based on the maximum opening dynamic load and the preset drag coefficient, and to iterate the initial critical section based on the preset drag coefficient to obtain the critical section. The maximum radial load and the maximum latitudinal load are calculated based on the critical section. The output module is used to generate umbrella fabric parameters based on the maximum radial load and the maximum weft load, obtain the preset number of paracords and upper straps, generate paracord parameters and upper strap parameters based on the maximum opening dynamic load, and output the area, the umbrella fabric parameters, the paracord parameters, and the upper strap parameters.

9. A terminal, characterized in that, The terminal includes: a memory, a processor, and a whole-aircraft parachute parameter generation program based on a bottom-edge extended parachute, which is stored in the memory and can run on the processor. When the whole-aircraft parachute parameter generation program based on a bottom-edge extended parachute is executed by the processor, it implements the steps of the whole-aircraft parachute parameter generation method based on a bottom-edge extended parachute as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a parachute parameter generation program based on a bottom-edge extended parachute, which, when executed by a processor, implements the steps of the parachute parameter generation method based on a bottom-edge extended parachute as described in any one of claims 1-7.

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