Solid rocket engine boosting separation method based on speed constraint

Abstract

The invention relates to a solid rocket engine boosting separation method based on speed constraint, and the method comprises the following steps: S1, measuring the altitude ht, the speed Vt and the axial overload nx of a target projectile in real time, and calculating the trajectory inclination angle theta t of the target projectile; s2, interpolating the two-dimensional expected speed interpolation table Vd (h, theta) according to the altitude ht and the ballistic inclination angle theta t of the target projectile at the current moment to obtain an expected speed Vd at the current moment, h being the altitude and theta being the ballistic inclination angle; s3, the step S1 and the step S2 are executed repeatedly, the real-time speed Vt is judged, and the moment Ts when the target missile speed meets the delayed separation condition and the moment Ti when the engine finishes working are recorded; and S4, delay separation judgment is carried out, the target missile separation moment Tp is determined, and boosting separation is carried out at the target missile separation moment Tp. According to the method, the speed and height of the separation point are restrained, so that trajectory dispersion caused by large trajectory energy difference is reduced, and the target supply precision is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft control, and relates to a solid rocket engine boost separation method based on speed constraint, which belongs to a boost separation method for reducing the ballistic dispersion of the unpowered section by delayed separation. Background Art

[0002] With the rapid development of air defense weapons and equipment, target missiles have played an important role as specific battlefield target simulators to assess the combat performance of equipment and improve the training level. Since the cost of using a target drone to drop target missiles is high and the low flight speed affects the training effect, it is considered to use a solid rocket engine as a booster. After the booster separation, the target section climbs to a specified altitude at a certain speed to complete the target supply task. This method reduces the test cost, but under different launch conditions such as temperature and altitude, the non-adjustable thrust characteristics of the solid rocket engine cannot effectively control the ballistic energy, and there is a possibility that the speed and altitude of the target supply section do not meet the target supply requirements. Therefore, it is necessary to design a separation strategy to constrain the speed and altitude of the target missile separation point to reduce the ballistic dispersion of the unpowered section. Summary of the invention

[0003] The technical problem solved by the present invention is: for a target missile using a solid rocket engine as a booster, a solid rocket engine booster separation method based on speed constraint is provided, the speed and height of the separation point are constrained, thereby reducing the ballistic dispersion caused by the large difference in ballistic energy and improving the target supply accuracy.

[0004] The solution to the technical problem of the present invention is: a solid rocket engine boost separation method based on speed constraint, the method comprising the following steps:

[0005] S1. Real-time measurement of target missile altitude h t , speed V t , axial overload n x , calculate the ballistic inclination angle θ of the target missile t ;

[0006] S2, according to the current altitude h of the target missile t and the ballistic inclination angle θ t , for the two-dimensional expected velocity interpolation table V d (h,θ) interpolation, get the expected speed V at the current moment d , where h is the altitude and θ is the ballistic inclination angle;

[0007] S3, repeat steps S1 and S2, and adjust the real-time speed V t Make a judgment and record the time Ts when the target missile speed meets the delayed separation condition and the time Ti when the engine has finished working;

[0008] S4. Perform a delayed separation judgment to determine the separation moment Tp of the target missile, and conduct a boost separation at the separation moment Tp of the target missile.

[0009] The delayed separation judgment is as follows:

[0010] If Ts < Ti, then perform a boost separation at the moment Ti when the engine has ended operation; otherwise, compare the moment Ts when the target missile speed meets the delayed separation condition with the preset latest separation time Te. If Ti ≤ Ts < Te, then perform a boost separation at the moment Ts when the target missile speed meets the delayed separation condition; if Ts ≥ Te, then perform a boost separation at the preset latest separation moment Te.

[0011] Preferably, if the target missile speed V obtained by continuous M measurements t is less than the corresponding expected speed V d , it is considered that the target missile speed meets the delayed separation condition, and M is greater than or equal to 10.

[0012] Preferably, if the axial overload n obtained by continuous M measurements x is less than 0, it is considered that this is the moment when the engine has ended operation, and M is greater than or equal to 10.

[0013] Preferably, the two-dimensional expected speed interpolation table V d (h, θ) is obtained by the following method:

[0014] S11. Take the trajectory separated at engine shutdown as the immediate separation trajectory, conduct a Monte Carlo simulation on the immediate separation trajectory, and statistically obtain the range of change in the ballistic inclination angle at the separation moment;

[0015] S12. Take the range of change in the ballistic inclination angle at the separation moment as the value range of the ballistic inclination angle θ in the two-dimensional expected speed interpolation table (θ min , θ max ), take interpolation points at a certain angular step, and obtain the sequence of ballistic inclination angles in the two-dimensional expected speed interpolation table;

[0016] S13. Determine the value range of the altitude h in the two-dimensional expected speed interpolation table (h min , h max ), take the delivery altitude required by the index as the maximum altitude h max , take h min = 1000m, take interpolation points at a certain altitude step, and obtain the sequence of altitudes in the two-dimensional expected speed interpolation table;

[0017] S14. Select a trajectory with a speed and altitude that meet the target supply requirements among all the trajectories with a ballistic inclination angle of θ min at the separation moment, and select the speed of the corresponding points in the altitude - speed curve of this trajectory as the two-dimensional expected speed interpolation table Vd The first row of (h,θ);

[0018] S15, select a trajectory whose speed and altitude meet the target supply requirements from all the trajectories whose trajectory inclination angle at the separation moment is another value in the trajectory inclination angle sequence, and select the speed of the corresponding point in the altitude sequence from the altitude-speed curve of this trajectory as the two-dimensional expected speed interpolation table V d The second row of (h,θ);

[0019] S16, traverse all the ballistic inclination angles in the ballistic inclination angle sequence at the separation time, repeat step S15, and obtain a complete two-dimensional expected velocity interpolation table V d (h,θ).

[0020] Preferably, the angle step is 2°.

[0021] Preferably, the altitude step is 1000m.

[0023] Preferably, the preset latest separation time Te is selected as the moment when the target missile reaches a preset altitude in the standard trajectory of the target missile.

[0024] The beneficial effects of the present invention compared with the prior art are:

[0025] (1) The method of the present invention delays the separation of the engine after the entire missile reaches a suitable speed and altitude, thereby creating suitable initial conditions for the target stage climb, reducing the ballistic dispersion caused by the ballistic energy difference, and improving the comprehensive performance of the target missile;

[0026] (2) The present invention is more inclusive of the performance of solid rocket engines and unpowered segment control systems, thus reducing the pressure on system design and development;

[0027] (3) The solid rocket engine target missile boost separation method based on speed constraint provided by the present invention can effectively constrain the speed and height of the target missile at the separation point, and the method is simple and easy to implement;

[0028] (4) The present invention can adjust the speed and height of the target supply section of the target missile by adjusting the expected speed in the strategy, so it can adapt to different target supply requirements and improve the applicability of the target missile. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a flow chart of a solid rocket motor target missile boost separation method based on velocity constraints according to an embodiment of the present invention.

[0030] FIG2( a ) is a simulation result of the delayed separation altitude of the target missile in a low temperature environment of -40° according to an embodiment of the present invention;

[0031] FIG2( b ) is a simulation result of the delayed separation speed of the target missile in a low temperature environment of -40°C according to an embodiment of the present invention;

[0032] FIG2( c ) is a simulation result of the delayed separation altitude of the target missile under a normal temperature environment of 20° according to an embodiment of the present invention;

[0033] FIG2( d ) is a simulation result of the delayed separation speed of the target missile under a normal temperature and 20° environment according to an embodiment of the present invention;

[0034] FIG2( e ) is a simulation result of the delayed separation altitude of the target missile in a high temperature environment of 55° according to an embodiment of the present invention;

[0035] FIG2( f ) is a simulation result of the delayed separation speed of the target missile in a high temperature environment of 55° according to an embodiment of the present invention;

[0036] FIG3( a ) is a simulation result of the target missile instant separation altitude under a low temperature environment of -40° in an embodiment of the present invention;

[0037] FIG3( b ) is a simulation result of the target-missile instant separation velocity in a low temperature environment of -40°C according to an embodiment of the present invention;

[0038] FIG3( c ) is a simulation result of the target missile instant separation altitude under a normal temperature 20° environment according to an embodiment of the present invention;

[0039] FIG3( d ) is a simulation result of the target-missile instant separation velocity under a normal temperature of 20° in an embodiment of the present invention;

[0040] FIG3( e ) is a simulation result of the target missile instant separation altitude under a high temperature environment of 55° according to an embodiment of the present invention;

[0041] FIG3( f ) is a simulation result of the instant separation speed of the target and missile in a high temperature environment of 55° according to an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The present invention will be further described below in conjunction with the embodiments.

[0043] After the solid rocket engine finishes working, it enters the unpowered flight phase. At this time, if the booster does not separate, the engine can consume part of the energy as a payload. When the entire missile reaches the appropriate speed and altitude, the engine separates, thereby creating suitable initial conditions for the target segment climb to reduce subsequent ballistic dispersion.

[0044] like Figure 1 As shown, the present invention provides a solid rocket engine target missile boost separation method based on velocity constraint. The specific technical solution is as follows:

[0045] (1) Determine the time Ti when the engine has finished working. The time when the engine has finished working is taken as the earliest separation time to ensure that the booster does not separate before the engine is turned off, and the booster separation judgment begins after the engine is turned off.

[0046] (2) Determine the latest separation time Te. Since the control system starts after the boost separation, if the boost separation is too late, the control system will not be able to fully exert its control function if the boost separation is too short. Considering that the atmosphere above 8 km altitude is relatively thin and the aerodynamic force is weakened, the time when the target missile in the standard trajectory reaches 8 km altitude is selected as the latest separation time Te, which can be appropriately adjusted according to the simulation verification results.

[0047] (3) Determine the two-dimensional expected speed interpolation table Vd(h, θ). The position at the separation moment and the magnitude and direction of the speed affect the speed and altitude dispersion of the highest point of the unpowered flight segment. Therefore, the altitude h and the trajectory inclination θ are selected as independent variables, and the speed is selected as the dependent variable. The expected speed Vd(h, θ) is determined as the delayed separation speed judgment condition.

[0048] Two-dimensional expected speed interpolation table V d (h,θ) is obtained by the following method:

[0049] S11, taking the trajectory of separation when the engine is turned off as the instant separation trajectory, performing Monte Carlo simulation on the instant separation trajectory, and statistically analyzing the range of trajectory inclination at the separation moment; the Monte Carlo simulation simulates the instant separation trajectory under high temperature, normal temperature, and low temperature conditions respectively, such as Figure 2(a) to Figure 2(f) shown.

[0050] The overall parameter interference of Monte Carlo simulation is considered in 7 categories and 31 items, including initial disturbance, separation disturbance, mass inertia deviation, power performance deviation, aerodynamic parameter deviation, wind speed, atmospheric parameter deviation, etc. The maximum deviation of the interference quantity is the limit deviation (3σ), and the probability that the random interference value falls within the limit deviation range is 99.74%.

[0051] S12, taking the range of the trajectory inclination angle at the separation time as the range of the trajectory inclination angle θ in the two-dimensional expected velocity interpolation table (θ min ,θ max ), interpolation points are taken at certain angle steps to obtain the trajectory inclination sequence in the two-dimensional expected velocity interpolation table; taking the angle step of 2° as an example, the trajectory inclination θ can be written as θ=[θ min ,θ mi + n 2,θ m + in 4,...θ,.

[0052] S13, determine the value range of the altitude h in the two-dimensional expected speed interpolation table (h min ,h max) Take the delivery height required by the index as the maximum altitude h max , take h min = 1000m, and take interpolation points at a certain altitude step interval to obtain the altitude sequence in the two-dimensional expected velocity interpolation table; if the altitude step is 1000m, then the altitude h can be written as h = [1000, 2000, 3000, …, h max .

[0053] S14. Select a trajectory with a ballistic inclination angle of θ min at all separation times, and select the velocity at the corresponding points of the altitude sequence in the altitude-velocity curve of this trajectory as the first row of the two-dimensional expected velocity interpolation table V d (h, θ);

[0054] S15. Select a trajectory with a ballistic inclination angle of another value in the ballistic inclination angle sequence at all separation times, and select the velocity at the corresponding points of the altitude sequence in the altitude-velocity curve of this trajectory as the second row of the two-dimensional expected velocity interpolation table V d (h, θ);

[0055] S16. Traverse all ballistic inclination angles in the ballistic inclination angle sequence at separation times, and repeat step S15 to obtain the complete two-dimensional expected velocity interpolation table V d (h, θ).

[0056] (4). Determine the time Ts when the target missile velocity satisfies the delayed separation condition. Use the real-time altitude h t and the ballistic inclination angle θ t to interpolate the interpolation table V d (h, θ), and the real-time expected velocity V d can be obtained. If the real-time velocity V t of the target missile at a certain time is less than the expected velocity V d , record this time as the time Ts when the target missile velocity satisfies the delayed separation condition.

[0057] (5). Delayed separation judgment to determine the separation time Tp. During the flight of the target missile, separation judgment is carried out in real time. If Ts < Ti, then Tp = Ti; if Ti ≤ Ts < Te, then Tp = Ts; when T ≥ Te, if Ts ≥ Te still holds, then Tp = Te. The target missile performs boost separation at the separation time Tp and starts unpowered flight until the flight.

[0058] Embodiment:

[0059] The present invention will be further described below in conjunction with the embodiments:

[0060] The steps of this embodiment are as follows:

[0061] (1) Determine the two-dimensional expected velocity interpolation table V d (h,θ) and the latest separation time Te, and write them into the missile-borne computer. The initial values of the earliest separation time, delay separation time, and separation time are set as Ti = Ts = Tp = 999, and the parameter values can only be modified once;

[0062] (2) During the flight of the target missile, the navigation device measures and outputs the altitude h t , velocity V t , axial overload n x and other data in real time, and calculates the real-time ballistic inclination angle θ t using the output velocity value. Interpolate V d (h,θ) to obtain the expected velocity V d at the current moment T;

[0063] (3) Judge the axial overload n x . If n x is less than 0 for ten consecutive frames, it is considered that the engine has stopped working, and the moment Ti when the engine has stopped working is assigned at this time;

[0064] (4) Judge the real-time velocity V t . If V t is less than V d for ten consecutive frames, it is considered that the target missile velocity meets the delay separation condition, and the moment Ts when the target missile velocity meets the delay separation condition is assigned at this time;

[0065] (5) When T < Te, compare the moment Ti when the engine has stopped working, the moment Ts when the target missile velocity meets the delay separation condition, and the latest separation moment Te in real time. If Ts < Ti, the boost separation will occur at the moment Ti when the engine has stopped working; otherwise, compare the moment Ts when the target missile velocity meets the delay separation condition with the preset latest separation time Te. If Ti ≤ Ts < Te, the boost separation will occur at the moment Ts when the target missile velocity meets the delay separation condition; if Ts ≥ Te, the boost separation will occur at the preset latest separation moment Te.

[0066] This embodiment conducts ballistic simulations on the delay separation and immediate separation of the target missile in environments of low temperature -40°, normal temperature 20°, and high temperature 55°, and obtains the statistics of the velocity and altitude dispersion, as shown in the following table and Figure 2(a) to Figure 3(f) , Figure 3(a) to Figure 3(f) .

[0067] Table 1 Statistics of Velocity and Altitude Dispersion

[0068]

[0069] It can be seen from the above table that the solid rocket engine target missile boost separation method based on velocity constraint provided by the present invention can reduce the ballistic dispersion caused by large differences in ballistic energy and improve the target supply accuracy.

[0070] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A solid rocket engine boost separation method based on velocity constraints, characterized in that The steps include the following: S1. Real-time measurement of target missile altitude h t , speed V t , axial overload n x , calculate the ballistic inclination angle θ of the target missile t ; S2, according to the current altitude h of the target missile t and the ballistic inclination angle θ t , for the two-dimensional expected velocity interpolation table V d (h,θ) interpolation, get the expected speed V at the current moment d , where h is the altitude and θ is the ballistic inclination angle; S3, repeat steps S1 and S2, and adjust the real-time speed V t Make a judgment and record the time Ts when the target missile speed meets the delayed separation condition and the time Ti when the engine has finished working; S4. Conduct a delayed separation judgment to determine the target missile separation moment Tp, and conduct a boost separation at the target missile separation moment Tp.

2. The solid rocket engine target missile boost separation method based on velocity constraint according to claim 1, characterized in that: The delayed separation judgment is as follows: If Ts < Ti, conduct a boost separation at the moment Ti when the engine has ended operation; otherwise, compare the moment Ts when the target missile speed meets the delayed separation condition with the preset latest separation time Te. If Ti ≤ Ts < Te, conduct a boost separation at the moment Ts when the target missile speed meets the delayed separation condition; if Ts ≥ Te, conduct a boost separation at the preset latest separation moment Te.

3. The solid rocket engine target missile boost separation method based on velocity constraint according to claim 1, characterized in that: If the target velocity V obtained by M consecutive measurements t Less than the corresponding expected speed V d , then the target missile velocity is considered to meet the delayed separation condition, and M is greater than or equal to 10.

4. The solid rocket engine target missile boost separation method based on velocity constraint according to claim 1, characterized in that: If the axial overload n obtained by M consecutive measurements is x If it is less than 0, it is considered that the engine has finished working at this time, and M is greater than or equal to 10.

5. The solid rocket engine target missile boost separation method based on velocity constraint according to claim 1, characterized in that: Two-dimensional expected speed interpolation table V d (h,θ) is obtained by the following method: S11. Take the trajectory of separation at engine shutdown as the immediate separation trajectory, conduct Monte Carlo simulation on the immediate separation trajectory, and statistically obtain the range of change in the ballistic inclination angle at the separation moment. S12, taking the range of the trajectory inclination angle at the separation time as the range of the trajectory inclination angle θ in the two-dimensional expected velocity interpolation table (θ min ,θ max ), taking interpolation points at certain angle steps to obtain the trajectory inclination angle sequence in the two-dimensional expected velocity interpolation table; S13, set the value range of the altitude h in the two-dimensional expected speed interpolation table (h min ,h max ), taking interpolation points at certain altitude steps to obtain an altitude sequence in a two-dimensional desired speed interpolation table; S14, the ballistic inclination angle at all separation moments is θ min Select a trajectory whose speed and altitude meet the target supply requirements from the trajectory, and select the speed of the corresponding point of the altitude sequence in the height-speed curve of this trajectory as the two-dimensional expected speed interpolation table V d The first row of (h,θ); S15, select a trajectory whose speed and altitude meet the target supply requirements from all trajectories whose trajectory inclination angle at the separation moment is another value in the trajectory inclination angle sequence, and select the speed of the corresponding point in the altitude sequence from the altitude-speed curve of this trajectory as the two-dimensional expected speed interpolation table V d The second row of (h,θ); S16, traverse all the ballistic inclination angles in the ballistic inclination angle sequence at the separation time, repeat step S15, and obtain a complete two-dimensional expected velocity interpolation table V d (h,θ).

6. The solid rocket engine target missile boost separation method based on velocity constraint according to claim 1, characterized in that: The release height required by the indicator is taken as the maximum altitude h max , take h min =1000m.

7. The solid rocket motor target missile boost separation method based on velocity constraint according to claim 1, characterized in that: The angle step size is taken as 2°.

8. The solid rocket engine target missile boost separation method based on velocity constraint according to claim 1, characterized in that: The altitude step size is taken as 1000 m.

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