Control methods and systems for low-altitude, low-speed level flight ejection using rocket ejection seats

Abstract

This invention discloses a control method and system for low-altitude, low-speed level flight ejection using a rocket ejection seat. The method involves analyzing real-time attitude data of the seat to predict future attitude changes and the pitch adjustment capability of the rocket engine, thereby controlling the timing of parachute deployment. If the rocket engine is deemed capable of providing pitch correction, the parachute is deployed after the engine has finished firing. If the rocket engine is deemed incapable of providing pitch correction, affecting parachute safety, the parachute is deployed earlier than planned, provided the engine has not finished firing and the seat attitude meets safety requirements. This prevents the parachute from being deployed ahead of the passenger's seat movement after the engine has finished firing, and utilizes the head-up torque generated by the parachute's deceleration to suppress the seat's continuous head-down motion. This application avoids the "passenger chasing the parachute" phenomenon during low-altitude, low-speed level flight ejection and can adapt to occupants of different weights.

Description

Technical Field

[0001] This invention belongs to the field of aircraft lifesaving, specifically relating to a control method and system for low-altitude, low-speed level flight ejection using a rocket ejection seat. Background Technology

[0002] The rocket ejection seat is equipped with ejection cartridges, a rocket engine, a separation incendiary cartridge, and parachute cartridges. These power components are activated by an electrical ignition signal output from a firing mechanism or an electronic program controller, and can only be activated once. This provides power to the seat during each stage from ejection to parachute deployment: when the pilot pulls the central pull ring, ejection is initiated and the ejection cartridge is fired. The ejection cartridge provides the first-stage thrust for ejection. After ejection, the rocket engine activates, providing the second-stage thrust for the seat. The rocket engine's thrust duration is t. 火箭 Typically, it takes 0.3 to 0.35 seconds. When the seat meets the conditions for separation and parachute deployment, the separation incendiary bomb and the parachute gun bullet are activated. The separation incendiary bomb breaks the restraint between the pilot and the seat, and the parachute gun bullet causes the parachute box containing the life-saving parachute canopy to be launched. After the parachute lines are straightened, the canopy is pulled out of the parachute box, ensuring that the pilot can safely decelerate and land after separating from the seat.

[0003] like Figure 1 As shown, the ejection direction of the ejection system, which is typically powered by the seat, is at an angle θ with the Y-axis of the seat coordinate system in the pitch direction. 弹射 To ensure the parachute is inflated by the airflow along the seat direction after launch, thus shortening the parachute deployment time, the parachute gun fires backward. Firing backward along the flight direction accelerates the inflation and full opening of the parachute canopy. The direction of the parachute gun's firing direction forms a certain angle θ with the Y-axis of the seat coordinate system in the pitch angle. 射伞 , and θ 射伞 >θ 弹射 When the parachute is fully inflated, the cone angle θ formed by the parachute canopy and the pilot is a conical envelope. 伞 .

[0004] To improve the minimum safe ejection altitude performance of the ejection seat, different control strategies need to be adopted for different ejection conditions based on the seat's real-time attitude data, so that the seat can achieve a higher ejection altitude and a better parachute attitude. However, during low-altitude, low-speed level flight ejection, because the seat attitude is not complex and the attitude angle is small, the ejection trajectory altitude can meet the safety requirements. In this condition, ejection control typically does not perform attitude adjustments; the parachute deployment and seat separation procedure are initiated immediately after the seat's rocket engine has finished firing.

[0005] However, in actual ejection tests, due to the low ejection speed and the lack of significant aerodynamic force, the seat stabilization system has relatively low attitude adjustment capability in the pitch direction. This results in a large nose-down angular velocity generated by the power of the first-stage ejection after ejection. After ejection separation, due to the different weights of the occupants, the thrust generated by the second-stage rocket engine is relatively small compared to the nose-up eccentricity moment generated by the overall center of gravity of the pilot-seat system when a heavier pilot ejects, or even a nose-down eccentricity moment occurs. This means that the thrust of the rocket engine cannot offset the nose-down angular velocity during ejection, and may even accelerate the nose-down tendency of the pilot-seat system. As a result, when the rocket engine finishes its work and the parachute separation procedure is executed, the parachute is directed towards the front of the pilot-seat flight. The parachute decelerates rapidly after the canopy opens, while the occupant continues to move forward after separating from the ejection seat, resulting in a "pilot chasing parachute" phenomenon. This causes the occupant to become entangled with the parachute lines or canopy, seriously affecting rescue safety. Summary of the Invention

[0006] The purpose of this invention is to provide a control method for low-altitude, low-speed, level flight ejection of a rocket ejection seat, and a control system for low-altitude, low-speed, level flight ejection of a rocket ejection seat based on the above method. This application can avoid the phenomenon of "person chasing parachute" in the low-altitude, low-speed, level flight ejection condition and can adapt to occupants of different weights.

[0007] The technical solution adopted in this invention is:

[0008] A control method for low-altitude, low-speed, level flight ejection of a rocket ejection seat involves analyzing the seat's real-time attitude data to predict future attitude changes and the rocket engine's pitch adjustment capability, thereby controlling the timing of parachute deployment. If it is determined that the rocket engine can meet the pitch correction requirements, the parachute is deployed after the rocket engine has finished operating. If it is determined that the rocket engine cannot meet the pitch correction requirements, which would affect parachute deployment safety, the parachute is deployed earlier if the rocket engine has not finished operating and the seat attitude meets the safety requirements for parachute deployment. This avoids the parachute deployment direction being in front of the seat's movement after the rocket engine has finished operating, and utilizes the head-up torque generated by the parachute's deceleration to suppress the seat's continuous head-down effect.

[0009] Furthermore, first determine the absolute value of the roll angular velocity |ω| at the moment of launch initiation. x启动 |,if|ω x启动 If | < threshold ω1, then the lateral parachute condition is not met, and the control branch 1 for early parachute deployment is entered. x启动 If |≥ω1, then the lateral parachute condition is met, and the control branch 2 of the conventional parachute is entered;

[0010] In branch line 1: First, control the rocket engine to operate at the moment of ejection from the seat, then delay for t2 to allow the rocket engine to stabilize, and adjust the real-time pitch angular velocity ω accordingly. z实时 Moving average calculation of pitch acceleration α z实时 Then delay for t3 to obtain sufficient data before making subsequent judgments, when α z实时 When Δθ is greater than or equal to the threshold α1, the pitch angle acceleration provided by the rocket engine is relatively large. The pitch angle increment Δθ for the remaining working time of the rocket engine is then calculated. If Δθ ≥ the threshold θ1, then Δθ obviously meets the requirements for subsequent conventional parachute deployment, and the parachute separation procedure begins after the rocket engine finishes its work. If Δθ < θ1, then the real-time pitch angle θ is further determined. 实时 If θ 实时 If ≥ threshold θ2, then θ 实时 Clearly, it meets the requirements for subsequent conventional parachute deployment and enters the parachute separation procedure after the rocket engine has finished firing. If θ 实时 If α < θ2, then the parachute will be deployed earlier after a delay of t4 and will separate after the rocket engine has finished firing; when α z实时 When α < 1, the nose-up acceleration provided by the rocket engine is relatively small, and further determination of ω z实时 If ω z实时 If ω ≥ threshold ω2, then ω z实时 Clearly, it meets the requirements for subsequent conventional parachute deployment and enters the parachute separation procedure after the rocket engine has finished firing. If ω z实时 If ω2 < ω2, then the parachute will be launched earlier after a delay of t5 and will separate after the rocket engine has finished working;

[0011] In branch line 2: First, control the rocket engine to operate at the moment of seat exit, and then enter the separation parachute procedure after the rocket engine has finished operating.

[0012] Furthermore, the absolute value of the roll angular velocity at the moment of launch initiation |ω x启动 The principle for determining the threshold ω1 is: ensuring that within the time range from the parachute launch to the tautness of the parachute lines, the change in the seat's roll angle exceeds half the value θ of the cone angle of the cone envelope formed by the parachute canopy and the pilot after the parachute is fully inflated. 伞 / 2.

[0013] Furthermore, the method for controlling the rocket engine to operate at the moment of seat ejection is as follows: set ejection start switch K1 and seat ejection start switch K2. K1 operates at the moment of seat ejection, at which time T1 = 0s. K2 operates at the moment of seat ejection, at which time T2 = 0s. The moment when K2 operates is the timing for the rocket engine to operate, or the moment when T1 ≥ t1 is the timing for the rocket engine to operate, where t1 is the time from seat ejection start to ejection.

[0014] Furthermore, the delay time t2 is the time from the generation of thrust to its stabilization after the rocket engine ignites; the delay time t3 is the time for the moving average calculation of pitch angle acceleration, and t3 is no less than 3 times the data refresh cycle.

[0015] Furthermore, the pitch acceleration α after ejection from the ejection chamber z实时 The principle for determining the threshold α1 is: to ensure that when the rocket engine finishes working, the pitch angle increment of the seat parachute direction during the rocket engine's working time is not less than 0° or not less than half the cone angle θ of the conical envelope formed by the parachute canopy and the pilot after the parachute is fully inflated. 伞 / 2.

[0016] Furthermore, the threshold θ1 for determining the pitch angle increment Δθ during the remaining operating time of the rocket engine is the pitch angle between the direction of the seat parachute and the direction of seat ejection, i.e., θ1 = θ 射伞 -θ 弹射 Real-time pitch angle θ after ejection 实时 The principle for determining the threshold θ2 is: to ensure that the seat pitch angle is not lower than 0° when the rocket engine finishes working.

[0017] Furthermore, the real-time pitch angular velocity ω after ejection from the capsule z实时 The principle for determining the threshold ω2 is: ensure that under pitch acceleration α1, the pitch angle increment is not less than the pitch angle between the direction of the seat parachute and the direction of seat ejection.

[0018] Furthermore, the delay time t4 does not satisfy the conditions for lateral parachute deployment, the rocket engine provides a large nose-up acceleration, and Δθ and θ 实时 The delayed parachute time t5 is insufficient to meet the requirements for subsequent conventional parachute launches. This delay time t5 does not meet the conditions for lateral parachute launch, the rocket engine provides insufficient nose-up acceleration, and ω... z实时 The delayed parachute time, which is insufficient to meet the requirements of subsequent conventional parachute launches, is determined by a comprehensive evaluation of the trajectory height performance of the corresponding human-chair mass.

[0019] A control system for low-altitude, low-speed level flight ejection using a rocket ejection seat includes an electronic programmable controller mounted on the seat. After being powered on, the electronic programmable controller collects real-time speed, altitude, and attitude data of the seat. When ejection is initiated under low-altitude, low-speed level flight conditions, the control method described above for low-altitude, low-speed level flight ejection using the rocket ejection seat controls the rocket engine, separation incendiary projectile, and parachute projectile to complete corresponding actions based on the real-time attitude data.

[0020] The beneficial effects of this invention are:

[0021] This application can avoid the phenomenon of "people chasing the parachute" and prevent the occupant from getting entangled with the parachute lines or canopy under the condition of low-altitude, low-speed, level flight ejection, thus ensuring the safety of life-saving under the condition of low-altitude, low-speed, level flight ejection, and can adapt to occupants of different weights. Attached Figure Description

[0022] Figure 1 This is a side view of the man-chair-umbrella system during rocket ejection.

[0023] Figure 2 This is a logic flowchart of the control method for low-altitude, low-speed level flight ejection of a rocket ejection seat in an embodiment of the present invention. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0025] Example 1

[0026] This embodiment provides a control method for low-altitude, low-speed level flight ejection using a rocket ejection seat. The principle is as follows:

[0027] In the case of low-altitude, low-speed, level flight ejection, by analyzing the real-time attitude data of the seat, the future attitude change trend of the seat and the pitch adjustment capability of the rocket engine are predicted, thereby controlling the timing of parachute deployment: if it is determined that the rocket engine can meet the pitch direction correction, the parachute is deployed after the rocket engine has finished working; if it is determined that the rocket engine cannot meet the pitch direction correction and will affect the safety of parachute deployment, the parachute is deployed in advance before the rocket engine has finished working and the seat attitude meets the safety requirements for parachute deployment. This avoids the parachute deployment direction being in front of the human-seat movement after the rocket engine has finished working, and the head-up torque generated by the deceleration of the parachute is used to suppress the continuous head-down effect of the seat.

[0028] In this embodiment, as Figure 2 As shown, the specific control flow is as follows:

[0029] When a pilot needs to eject under low-altitude, low-speed level flight conditions, they first pull the central trigger ring, which fires the ejection cartridge and initiates seat movement. The ejection activation switch K1 also activates (at this moment, T1 = 0s), confirming ejection activation. Afterwards:

[0030] 1. Typically, the ejection seat has an initial roll velocity after exiting the capsule. When the rocket engine finishes firing and enters the parachute separation procedure, the seat usually has a certain roll angle. Since the parachute direction is lateral when there is a certain roll, the risk of the person chasing the parachute is extremely small. Therefore, if the lateral parachute release condition is met, there is no need to determine whether to release the parachute in advance. Therefore, first determine the absolute value of the roll velocity at the moment of ejection initiation, |ω x启动 |,if|ω x启动If | < threshold ω1, then the lateral parachute condition is not met, and the control branch 1 for early parachute deployment is entered. x启动 If |≥ω1, then the lateral parachute condition is met, and the control branch 2 of the conventional parachute is entered.

[0031] The absolute value of the roll velocity at the moment of launch |ω x启动 The principle for determining the threshold ω1 is: ensuring that within the time range from the parachute launch to the tautness of the parachute lines, the change in the seat's roll angle exceeds half the value θ of the cone angle of the cone envelope formed by the parachute canopy and the pilot after the parachute is fully inflated. 伞 / 2, ω1 typically ranges from 50 to 80° / s.

[0032] 2a. In the case of branch 1:

[0033] 1) The moment the seat exits the cabin is when K2 starts working. At this moment, T2 = 0s. The moment when K2 starts working is the time when the rocket engine starts working, or when T1 ≥ t1 is the time when the rocket engine starts working. t1 is the time from the seat ejection start to exiting the cabin. t1 is usually in the range of 0.18 to 0.24s.

[0034] 2) Delay t2 to allow the rocket engine to stabilize. The delay time t2 is the time from the generation of thrust to the stabilization after the rocket engine is ignited. The value of t2 is determined according to the rocket engine and is usually in the range of 0.025 to 0.035 s.

[0035] 3) Based on the real-time pitch angular velocity ω z实时 Moving average calculation of pitch acceleration α z实时 Then, a delay of t3 is made to obtain sufficient data before subsequent judgment. The delay time t3 is the time for calculating the pitch angle acceleration by moving average. t3 is not less than 3 times the data refresh cycle. The value of t3 is determined by the sampling frequency and communication frequency of the MEMS inertial measurement module, and is usually in the range of 0.045 to 0.06 s.

[0036] 4) Pitch acceleration α after ejection z实时 The principle for determining the threshold α1 is: to ensure that when the rocket engine finishes working, the pitch angle increment of the seat parachute direction during the rocket engine's working time is not less than 0° or not less than half the cone angle θ of the conical envelope formed by the parachute canopy and the pilot after the parachute is fully inflated. 伞 / 2; α1 is typically selected within the range of 300–500° / s 2 .

[0037] 4.1) When α z实时 When the threshold α1 is greater than or equal to 1, the pitch angle acceleration provided by the rocket engine is larger. Continue calculating the pitch angle increment Δθ for the remaining operating time of the rocket engine, where Δθ = ω. z实时 (t 火箭-t2-t3)+0.5α z实时 (t 火箭 -t2-t3) 2 If Δθ ≥ threshold θ1, then Δθ obviously meets the requirements for subsequent conventional parachute deployment, and the parachute separation procedure will begin when T2 ≥ t6 (t6 is the time when the rocket engine finishes its work, and its value is determined according to the performance of the rocket engine; t6 is usually 0.3 to 0.35 s). If Δθ < θ1, then the real-time pitch angle θ is further determined. 实时 If θ 实时 If ≥ threshold θ2, then θ 实时 Clearly, the requirements for subsequent conventional parachute deployment are met, and the parachute separation procedure begins when T2 ≥ t6 (t6 is the time when the rocket engine finishes its work, and its value is determined based on the rocket engine's performance; t6 is typically 0.3–0.35 s). If θ 实时 If θ2 < θ2, then the parachute will be launched earlier after a delay of t4 and will separate after the rocket engine has finished working;

[0038] The threshold θ1 for determining the pitch angle increment Δθ during the remaining operating time of the rocket engine is the pitch angle between the direction of the seat parachute and the direction of seat ejection, i.e., θ1 = θ 射伞 -θ 弹射 θ1 is typically 25°–35°; the real-time pitch angle θ after ejection is... 实时 The principle for determining the threshold θ2 is: ensuring that the seat pitch angle is not lower than 0° when the rocket engine finishes working; θ2 is usually -15° to -5°. The delay time t4 is not satisfied with the lateral parachute conditions, the rocket engine provides a large nose-up acceleration, and Δθ and θ 实时 The delayed parachute launch time, which is insufficient to meet the requirements of subsequent conventional parachute launches, is determined by a comprehensive evaluation based on the trajectory height performance of the corresponding man-chair mass. It is typically 0.14 to 0.17 seconds after the rocket engine starts operating. Therefore, t4 ranges from 0.14-(t2+t3) to 0.17-(t2+t3) seconds.

[0039] 4.2) When α z实时 When α < 1: the nose-up acceleration provided by the rocket engine is relatively small, further determining ω z实时 If ω z实时 If ω ≥ threshold ω2, then ω z实时 Clearly, the requirements for subsequent conventional parachute deployment are met, and the parachute separation procedure begins when T2 ≥ t6 (t6 is the time it takes for the rocket engine to finish its work, and its value is determined based on the rocket engine's performance; t6 is typically 0.3–0.35 s). If ω z实时 If ω2 < ω2, then the parachute will be launched earlier after a delay of t5 and will separate after the rocket engine has finished working;

[0040] Among them, the real-time pitch angular velocity ω after ejection from the capsule z实时The principle for determining the threshold ω2 is: ensure that under pitch acceleration α1, the pitch angle increment is not less than the pitch angle (θ) between the direction of the seat parachute and the direction of seat ejection. 射伞 -θ 弹射 ), ω2 is typically 100–200° / s; the delay time t5 is insufficient due to the lack of lateral parachute conditions, the relatively small nose-up acceleration provided by the rocket engine, and ω z实时 The delayed parachute launch time, which is insufficient to meet the requirements of subsequent conventional parachute launches, is determined by a comprehensive evaluation based on the trajectory height performance of the corresponding man-chair mass. The parachute launch time is typically 0.18 to 0.2 seconds after the rocket engine starts operating. Therefore, t5 is 0.18-(t2+t3) to 0.2-(t2+t3) seconds.

[0041] 2b. In the case of branch 2:

[0042] 1) The moment the seat exits the cabin is when K2 starts working. At this moment, T2 = 0s. The moment when K2 starts working is the time when the rocket engine starts working, or the time when T1 ≥ t1 is the time when the rocket engine starts working, where t1 is the time from the seat ejection start to exiting the cabin (t1 is usually in the range of 0.18 to 0.24s).

[0043] 2) After the rocket engine finishes working, i.e., when T2≥t6, the separation parachute launch procedure begins. t6 is the time when the rocket engine finishes working, and its value is determined according to the performance of the rocket engine. t6 is usually 0.3 to 0.35s.

[0044] Example 2

[0045] This embodiment provides a control system for low-altitude, low-speed level flight ejection using a rocket ejection seat. The system includes an electronic programmable controller mounted on the seat. Upon power-up, the electronic programmable controller collects real-time speed, altitude, and attitude data of the seat. When ejection is initiated under low-altitude, low-speed level flight conditions, it uses the control method described in Embodiment 1 to control the rocket engine, the separation incendiary projectile, and the parachute projectile to complete corresponding actions based on the real-time attitude data. In this embodiment, the electronic programmable controller includes a MEMS inertial measurement module and multiple control boards, employing a DSP digital signal processing system. The MEMS inertial measurement module collects real-time speed, altitude, and the angles, angular velocities, and angular velocities along the heading, pitch, and roll axes. The control boards include processing chips, general-purpose I / O ports, general-purpose timers, power-on reset and monitoring circuits, A / D converters, control start signal circuits, ignition modules, and non-volatile memory, used for receiving, processing, and transmitting electrical signals.

[0046] Application example:

[0047] A new type of ejection seat is equipped with an electronic programmable controller capable of interacting with aircraft signals, sensing seat speed, altitude, and attitude in real time, and outputting electric ignition according to a pre-programmed control logic. Based on seat simulation and experimental verification, the following control parameter values ​​are specified: angle judgment thresholds θ1 = 30°, θ2 = -10°; angular velocity judgment thresholds ω1 = 60° / s, ω2 = 100° / s; angular acceleration judgment threshold α1 = 400° / s. 2 The time thresholds for each decision were t1 = 0.2s, t2 = 0.03s, t3 = 0.06s, t4 = 0.06s, t5 = 0.09s, and t6 = 0.3s. Furthermore, simulation calculations of the ejection seat performance were performed. Under zero-to-zero conditions, the minimum safe ejection height for occupants of all weights (large, medium, and small) was 0m, meeting the safety rescue height requirements. Furthermore, a comprehensive ejection test under zero-zero conditions was conducted. The test used a heavy-weight dummy to simulate the pilot. The test results showed that the pitch angle was -25° during parachute deployment, with the parachute direction pointing backwards in the same direction as the flight path. After the parachute was deployed, the recoil force of the parachute bullet caused the pitch angle of the seat system to continuously decrease until the rocket engine finished firing. With the deceleration pull of the life-saving parachute, the pitch attitude of the seat changed to head-up. At this time, the parachute lines were taut and began to inflate. The seat moved in front of the life-saving parachute canopy. After the separation incendiary bomb was fired, the dummy was decelerated and pulled out of the seat basin by the life-saving parachute. Throughout the process, the life-saving parachute remained behind the seat and did not interfere with the direction of movement of the seat, thus achieving the design goal of safe rescue.

[0048] This application can avoid the phenomenon of "people chasing the parachute" and prevent the occupant from getting entangled with the parachute lines or canopy under the condition of low-altitude, low-speed, level flight ejection, thus ensuring the safety of life-saving under the condition of low-altitude, low-speed, level flight ejection, and can adapt to occupants of different weights.

[0049] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

Claims

1. A control method for low-altitude, low-speed level flight ejection of a rocket ejection seat, characterized in that, In the case of low-altitude, low-speed, level flight ejection, by analyzing the real-time attitude data of the seat, the trend of future attitude changes of the seat and the pitch adjustment capability of the rocket engine are predicted, thereby controlling the timing of parachute launch: if it is determined that the rocket engine can meet the pitch direction correction, the parachute is launched after the rocket engine has finished working; if it is determined that the rocket engine cannot meet the pitch direction correction and will affect the safety of parachute launch, the parachute is launched in advance if the rocket engine has not finished working and the seat attitude meets the safety requirements for parachute launch, thereby avoiding the parachute launch direction being in front of the human-seat movement after the rocket engine has finished working, and using the head-up torque generated by the deceleration of the life-saving parachute to suppress the continuous head-down effect of the seat. First, determine the absolute value of the roll velocity at the moment of launch initiation |ω x启动 |,if|ω x启动 If | < threshold ω1, then the lateral parachute condition is not met, and the control branch 1 for early parachute deployment is entered. x启动 If |≥ω1, then the lateral parachute condition is met, and the control branch 2 of the conventional parachute is entered; In branch line 1: First, control the rocket engine to operate at the moment of ejection from the seat, then delay for t2 to allow the rocket engine to stabilize, and adjust the real-time pitch angular velocity ω accordingly. z实时 Moving average calculation of pitch acceleration α z实时 Then delay for t3 to obtain sufficient data before making subsequent judgments, when α z实时 When Δθ is greater than or equal to the threshold α1, the pitch angle acceleration provided by the rocket engine is relatively large. The pitch angle increment Δθ for the remaining working time of the rocket engine is then calculated. If Δθ ≥ the threshold θ1, then Δθ obviously meets the requirements for subsequent conventional parachute deployment, and the parachute separation procedure begins after the rocket engine finishes its work. If Δθ < θ1, then the real-time pitch angle θ is further determined. 实时 If θ 实时 If ≥ threshold θ2, then θ 实时 Clearly, it meets the requirements for subsequent conventional parachute deployment and enters the parachute separation procedure after the rocket engine has finished firing. If θ 实时 If α < θ2, then the parachute will be deployed earlier after a delay of t4 and will separate after the rocket engine has finished firing; when α z实时 When α < 1, the nose-up acceleration provided by the rocket engine is relatively small, and further determination of ω z实时 If ω z实时 If ω ≥ threshold ω2, then ω z实时 Clearly, it meets the requirements for subsequent conventional parachute deployment and enters the parachute separation procedure after the rocket engine has finished firing. If ω z实时 If ω2 < ω2, then the parachute will be launched earlier after a delay of t5 and will separate after the rocket engine has finished working; In branch line 2: First, control the rocket engine to operate at the moment of seat exit, and then enter the separation parachute procedure after the rocket engine has finished operating.

2. The control method for low-altitude, low-speed level flight ejection of a rocket ejection seat as described in claim 1, characterized in that, The absolute value of the roll velocity at the moment of launch |ω x启动 The principle for determining the threshold ω1 is: ensuring that within the time range from the parachute launch to the tautness of the parachute lines, the change in the seat's roll angle exceeds half the value θ of the cone angle of the cone envelope formed by the parachute canopy and the pilot after the parachute is fully inflated. 伞 / 2.

3. The control method for low-altitude, low-speed level flight ejection of a rocket ejection seat as described in claim 1, characterized in that, The method to control the rocket engine to work at the moment of seat ejection is as follows: set ejection start switch K1 and seat ejection start switch K2. K1 works at the moment of seat ejection, at which time T1=0s. K2 works at the moment of seat ejection, at which time T2=0s. The rocket engine can be considered to be operating at time K2, or at time T1≥t1, where t1 is the time from ejection seat activation to exiting the capsule.

4. The control method for low-altitude, low-speed level flight ejection of a rocket ejection seat as described in claim 1, characterized in that: The delay time t2 is the time from the generation of thrust to its stabilization after the rocket engine ignites; the delay time t3 is the time for the moving average calculation of pitch angle acceleration, and t3 is no less than 3 times the data refresh cycle.

5. The control method for low-altitude, low-speed level flight ejection of a rocket ejection seat as described in claim 1, characterized in that, Pitch acceleration α after ejection z实时 The principle for determining the threshold α1 is: to ensure that when the rocket engine finishes working, the pitch angle increment of the seat parachute direction during the rocket engine's working time is not less than 0° or not less than half the cone angle θ of the conical envelope formed by the parachute canopy and the pilot after the parachute is fully inflated. 伞 / 2.

6. The control method for low-altitude, low-speed level flight ejection of a rocket ejection seat as described in claim 1, characterized in that: The threshold θ1 for determining the pitch angle increment Δθ during the remaining operating time of the rocket engine is the pitch angle between the direction of the seat parachute and the direction of seat ejection, i.e., θ1 = θ 射伞 -θ 弹射 Real-time pitch angle θ after ejection 实时 The principle for determining the threshold θ2 is: to ensure that the seat pitch angle is not lower than 0° when the rocket engine finishes working.

7. The control method for low-altitude, low-speed level flight ejection of a rocket ejection seat as described in claim 1, characterized in that, Real-time pitch angular velocity ω after ejection z实时 The principle for determining the threshold ω2 is: ensure that under pitch acceleration α1, the pitch angle increment is not less than the pitch angle between the direction of the seat parachute and the direction of seat ejection.

8. The control method for low-altitude, low-speed level flight ejection of a rocket ejection seat as described in claim 1, characterized in that: The delay time t4 does not meet the conditions for lateral parachute launch, the rocket engine provides a large nose-up acceleration, and Δθ and θ 实时 The delayed parachute time t5 is insufficient to meet the requirements for subsequent conventional parachute launches. This delay time t5 does not meet the conditions for lateral parachute launch, the rocket engine provides insufficient nose-up acceleration, and ω... z实时 The delayed parachute time, which is insufficient to meet the requirements of subsequent conventional parachute launches, is determined by a comprehensive evaluation of the trajectory height performance of the corresponding human-chair mass.

9. A control system for low-altitude, low-speed level flight ejection using a rocket ejection seat, comprising an electronic programmable controller mounted on the seat, characterized in that: After the electronic program controller is powered on, it collects the real-time speed, altitude and attitude data of the seat. When it detects that the ejection is initiated under low-altitude, low-speed level flight conditions, it controls the rocket engine, the separation incendiary projectile and the parachute projectile to complete the corresponding actions according to the control method for low-altitude, low-speed level flight ejection of the rocket ejection seat as described in any one of claims 1 to 8.

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