Control method and system during low-altitude low-speed flat-flying ejection of rocket ejection seat

Abstract

The invention discloses a control method and system during low-altitude low-speed flat-flying ejection of a rocket ejection seat, and the method comprises the steps: predicting the future posture change trend of the seat and the pitching posture adjustment capability of a rocket engine through analyzing the real-time posture data of the seat under the low-altitude low-speed flat-flying ejection working condition of the seat; if it is judged that the rocket engine can meet the posture correction in the pitching direction, parachute shooting is controlled after the rocket engine finishes working, and if it is judged that the rocket engine cannot meet the posture correction in the pitching direction, parachute shooting safety can be affected, parachute shooting is controlled in advance under the conditions that the rocket engine does not finish working and the posture of a seat meets safe parachute shooting; therefore, the parachute shooting direction is prevented from being in front of the movement of the seat after the rocket engine finishes working, and the continuous head lowering effect of the seat is restrained by the head raising torque generated by deceleration of the escape parachute. The phenomenon that people catch up the umbrella can be avoided under the working condition of low-altitude low-speed flat-flying ejection, and the device can adapt to passengers with different weights.

Description

Technical Field

[0001] The invention belongs to the field of aircraft lifesaving, and in particular relates to a control method and system for a rocket ejection seat during low-altitude, low-speed and level-flight ejection. Background Art

[0002] The rocket ejection seat is equipped with an ejection projectile, a rocket engine, a separation explosive projectile and a parachute-shooting gun projectile. These power parts are activated by the electric ignition signal output by the firing structure or the electronic program controller and can only be activated once, thereby providing the seat with power from exiting the cabin to parachute shooting. When the pilot pulls the central pull ring, the ejection starts and the ejection projectile is fired. The ejection projectile provides the seat with the first-level power to exit the cabin. After the cabin exits, the rocket engine starts to work, providing the seat with the second-level power after exiting the cabin. The thrust duration of the rocket engine is t 火箭 It is usually 0.3 to 0.35s. When the seat meets the separation and parachute shooting conditions, the separation incendiary bomb and the parachute shooting gun bullet work. The separation incendiary bomb disconnects the restraint between the pilot and the seat, and the parachute shooting gun shoots out the life-saving canopy wrapped in the parachute box of the seat. After the parachute rope is straightened, the canopy is pulled out of the parachute box, ensuring that the pilot can safely decelerate and land after separation from the seat.

[0003] like Figure 1 As shown, the ejection direction of the ejection projectile of the seat's primary power usually has an angle θ with the Y axis of the seat coordinate system in the pitch direction 弹射 In order to ensure that the parachute is inflated by the flow from the seat heading after it is shot out and shorten the parachute opening time, the parachute shooting gun adopts the method of shooting the parachute backwards. Shooting the parachute backwards along the heading can speed up the inflation and full opening of the parachute canopy. There is a certain angle θ between the shooting direction of the parachute shooting gun and the Y axis of the seat coordinate system in the pitch angle. 射伞 , and θ 射伞 >θ 弹射 , the cone envelope angle θ formed by the canopy and the pilot after the lifesaving parachute is fully opened 伞 .

[0004] In order to improve the life-saving performance of the seat at the minimum safe height, it is necessary to adopt different control strategies for different ejection conditions based on the real-time attitude data of the seat, so that the seat can obtain a higher ejection height and a better parachute shooting attitude. During low-altitude, low-speed and level-flight ejection, since the seat attitude is not complicated, the attitude angle is small, and the ejection trajectory height can meet the safety life-saving requirements, the ejection control of this condition usually does not perform attitude adjustment, and the life-saving parachute is ejected and the person-chair separation procedure is carried out after the rocket engine of the seat has finished working.

[0005] However, in the actual ejection test, due to the low ejection speed, in the absence of large aerodynamic forces, the seat stabilization system has a relatively low ability to adjust the seat pitch direction, resulting in a relatively low head-down moment caused by the power generated by the first-stage ejection projectile after the seat is ejected out of the cabin. This will provide a large head-down angular velocity. After the ejection projectile separates, due to the different weights of the seat occupants, when a heavy pilot is ejected, the thrust generated by the second-stage power rocket engine is relatively small compared to the head-up eccentric moment generated by the overall center of gravity of the person-chair, and even a head-down eccentric moment may occur. As a result, the torque of the rocket engine thrust cannot offset the head-down angular velocity when exiting the cabin, and even accelerates the head-down trend of the person-chair system. As a result, when the rocket engine is finished working and the parachute separation procedure is executed, the parachute flies toward the front of the person-chair, and the ejected life-saving parachute decelerates rapidly after the canopy opens, while the occupants continue to move forward after separating from the ejection seat, eventually resulting in the phenomenon of "people chasing parachutes", causing the occupants to become entangled with the parachute ropes or canopy of the life-saving parachute, seriously affecting life-saving safety. Summary of the invention

[0006] The purpose of the present invention is to provide a control method for a rocket ejection seat during low-altitude, low-speed and level flight ejection, and a control system for a rocket ejection seat during low-altitude, low-speed and level flight ejection based on the above method. The present application can avoid the phenomenon of "people chasing parachutes" under the condition of low-altitude, low-speed and level flight ejection, and can adapt to passengers of different weights.

[0007] The technical solution adopted by the present invention is:

[0008] A control method for a rocket ejection seat during low-altitude, low-speed and level flight ejection. Under the seat low-altitude, low-speed and level flight ejection working condition, by analyzing the real-time attitude data of the seat, the trend of the seat's future attitude change and the rocket engine's pitch attitude adjustment capability are predicted, thereby controlling the timing of parachute shooting: if it is determined that the rocket engine can meet the pitch direction correction requirement, the parachute is controlled to be shot after the rocket engine is finished working; if it is determined that the rocket engine cannot meet the pitch direction correction requirement and will affect the parachute shooting safety, the parachute is controlled to be shot in advance when the rocket engine has not finished working and the seat attitude meets the safety parachute shooting requirement, thereby avoiding the parachute shooting direction being in front of the movement of the person in the chair after the rocket engine is finished working, and utilizing the head-up torque generated by the deceleration of the lifesaving parachute to suppress the continuous head-down effect of the seat.

[0009] Furthermore, the absolute value of the rolling angular velocity at the time of ejection start is first determined. x启动 |, if |ω x启动 |<threshold ω1, the side parachute shooting condition is not met and the control branch 1 of the early parachute shooting is entered. If |ω x启动 |≥ω1, the side parachute shooting condition is met and the control branch 2 of the conventional parachute shooting is entered;

[0010] In branch line 1: first control the rocket engine to work at the moment of seat exit, then delay t2 to wait for the rocket engine to work stably, and then adjust the pitch angle velocity ω according to the real-time z实时 Moving average calculation of pitch angle acceleration α z实时 , and then delay t3 to obtain sufficient data for subsequent judgment. z实时 ≥ threshold α1, the nose-up acceleration provided by the rocket engine is large, and the pitch angle increment △θ of the remaining working time of the rocket engine is continued to be calculated. If △θ ≥ threshold θ1, then △θ obviously meets the subsequent conventional parachute shooting requirements, and the separation parachute shooting program is entered after the rocket engine is finished working. If △θ < θ1, the real-time pitch angle θ is further determined. 实时 , if θ 实时 ≥ threshold θ2, then θ 实时 Obviously, it meets the subsequent conventional parachute shooting requirements and enters the separation parachute shooting procedure after the rocket engine is finished working. If θ 实时 <θ2, the parachute will be launched in advance after a delay of t4 and will separate after the rocket engine has finished working; when α z实时 When α<1, the nose-up angular acceleration provided by the rocket engine is small, and further determination of ω z实时 , if ω z实时 ≥ threshold ω2, then ω z实时 Obviously, it meets the subsequent conventional parachute shooting requirements and enters the separation parachute shooting procedure after the rocket engine is finished working. z实时 <ω2, the parachute will be launched in advance 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 work when the seat exits the cabin, and then enter the separation parachute shooting program after the rocket engine finishes working.

[0012] Furthermore, the absolute value of the rolling angular velocity at the time of ejection initiation |ω x启动 The principle of selecting the value of the judgment threshold ω1 of | is: to ensure that within the time range from the ejection of the lifesaving parachute to the straightening of the parachute rope, the roll angle change of the seat exceeds the half value θ of the cone envelope angle formed by the canopy and the pilot after the lifesaving parachute is fully inflated 伞 / 2.

[0013] Furthermore, the method for controlling the rocket engine to work at the time of seat exiting the cabin is: setting the ejection start switch K1 and the seat exiting the cabin start switch K2, the seat ejection start time is when K1 works, at this moment T1=0s, the seat exiting the cabin is when K2 works, at this moment T2=0s; the working time of K2 is the working time of the rocket engine, or, the working time of the rocket engine is when T1≥t1, and t1 is the time from the seat ejection start to the exiting the cabin.

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

[0015] Furthermore, the pitch acceleration α after ejection z实时 The principle of selecting the value of the judgment threshold α1 is to ensure that when the rocket engine is finished working, the pitch angle increment of the seat parachute shooting direction during the working time of the rocket engine is not less than 0° or not less than the half value θ of the cone envelope angle formed by the canopy and the pilot after the lifesaving parachute is fully opened 伞 / 2.

[0016] Furthermore, the determination threshold θ1 of the pitch angle increment Δθ of the remaining working time of the rocket engine is taken as the pitch angle between the seat parachute shooting direction and the seat ejection direction, that is, θ1 = θ 射伞 -θ 弹射 ; Real-time pitch angle θ after ejection 实时 The principle for selecting the value of the judgment threshold θ2 is to ensure that the seat pitch angle is not less than 0° when the rocket engine finishes working.

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

[0018] Furthermore, the delay time t4 is when the side parachute shooting condition is not met, the head-up angle acceleration provided by the rocket engine is large, △θ and θ 实时 The delayed parachute shooting time is not enough to meet the subsequent conventional parachute shooting requirements. The delay time t5 does not meet the side parachute shooting conditions, the head-up angle acceleration provided by the rocket engine is small, and ω z实时 The delayed parachute shooting time is not enough to meet the subsequent conventional parachute shooting requirements. The values ​​of both are comprehensively evaluated based on the trajectory height performance of the corresponding person-chair mass.

[0019] A control system for a rocket ejection seat during low-altitude, low-speed and level flight ejection, comprising an electronic program controller installed on the seat. After the electronic program controller is powered on, it collects real-time speed, altitude and attitude data of the seat, and when ejection is started under low-altitude, low-speed and level flight conditions, the control method for the rocket ejection seat during low-altitude, low-speed and level flight ejection is used to control a rocket engine, a separation explosive bomb and a parachute gun bullet according to the real-time attitude data to complete corresponding actions.

[0020] The beneficial effects of the present invention are:

[0021] The present application can avoid the phenomenon of "people chasing the parachute" and avoid entanglement between the crew and the parachute rope or canopy of the life-saving parachute under the condition of low-altitude, low-speed and level-flight ejection, thereby ensuring the life-saving safety under the condition of low-altitude, low-speed and level-flight ejection, and can adapt to crew members of different weights. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a side view of the person-seat-parachute system during the rocket ejection seat ejection.

[0023] Figure 2 It is a logic flow chart of the control method of the rocket ejection seat during low-altitude, low-speed and level flight ejection in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0025] Embodiment 1

[0026] This embodiment provides a control method for a rocket ejection seat during low-altitude, low-speed and level flight ejection, the principle of which is:

[0027] Under the condition of low-altitude, low-speed and level flight ejection of the seat, the real-time attitude data of the seat is analyzed to predict the trend of future seat attitude changes and the pitch adjustment capability of the rocket engine, thereby controlling the timing of parachute shooting: if it is judged that the rocket engine can meet the pitch direction correction requirements, the parachute is controlled to be shot after the rocket engine is finished working; if it is judged that the rocket engine cannot meet the pitch direction correction requirements and will affect the safety of parachute shooting, the parachute is controlled to be shot in advance when the rocket engine has not finished working and the seat attitude meets the requirements for safe parachute shooting, thereby avoiding the parachute shooting direction in front of the movement of the human chair after the rocket engine is finished working, and using the head-up torque generated by the deceleration of the lifesaving parachute to suppress the continuous head-down effect of the seat.

[0028] In this embodiment, if Figure 2 As shown, the specific control process is:

[0029] In low altitude, low speed and level flight, when the pilot needs to eject, he first pulls the central pull ring, which fires the ejection bullet, the seat starts to move, and the ejection start switch K1 also works (at this moment T1 = 0s), judging that the ejection is started. After that:

[0030] 1. Usually, the seat has an initial roll angular velocity after ejection. When the rocket engine is finished working and enters the separation parachute shooting procedure, the seat usually has a certain roll angle. Since the parachute shooting direction in a certain roll state is sideways, the risk of people chasing the parachute is extremely small. Therefore, if the sideways parachute shooting condition is met, there is no need to determine whether to shoot the parachute in advance. Therefore, the absolute value of the roll angular velocity at the time of ejection start |ω is first determined. x启动 |, if |ω x启动|<threshold ω1, the side parachute shooting condition is not met and the control branch 1 of the early parachute shooting is entered. If |ω x启动 |≥ω1, the side-shooting parachute condition is met and the control branch line 2 of the conventional parachute shooting is entered.

[0031] The absolute value of the rolling angular velocity at the time of ejection start |ω x启动 The principle of selecting the value of the judgment threshold ω1 of | is: to ensure that within the time range from the ejection of the lifesaving parachute to the straightening of the parachute rope, the roll angle change of the seat exceeds the half value θ of the cone envelope angle formed by the canopy and the pilot after the lifesaving parachute is fully inflated 伞 / 2, ω1 usually ranges from 50 to 80° / s.

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

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

[0034] 2) Delay t2 to wait for the rocket engine to stabilize. The delay time t2 is the time it takes for the thrust to grow from generation to stability after the rocket engine is ignited. The value of t2 is determined according to the rocket engine, usually in the range of 0.025 to 0.035s.

[0035] 3) According to the real-time pitch angular velocity ω z实时 Moving average calculation of pitch angle acceleration α z实时 , and then delay t3 to obtain sufficient data for subsequent judgment. The delay time t3 is the time for moving average calculation of pitch angle acceleration. 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, usually in the range of 0.045 to 0.06s.

[0036] 4) Pitch acceleration α after ejection z实时 The principle of selecting the value of the judgment threshold α1 is to ensure that when the rocket engine is finished working, the pitch angle increment of the seat parachute shooting direction during the working time of the rocket engine is not less than 0° or not less than the half value θ of the cone envelope angle formed by the canopy and the pilot after the lifesaving parachute is fully opened 伞 / 2; α1 is usually selected in the range of 300~500° / s 2 .

[0037] 4.1) When α z实时 ≥ threshold α1: the nose-up angular acceleration provided by the rocket engine is large, and the pitch angle increment △θ of the remaining working time of the rocket engine is continued to be calculated, △θ=ω z实时 (t 火箭-t2-t3)+0.5α z实时 (t 火箭 -t2-t3) 2 If △θ≥threshold θ1, then △θ obviously meets the subsequent conventional parachute launch requirements and enters the separation parachute launch procedure when T2≥t6 (t6 is the time when the rocket engine is finished working, which is determined according to the performance of the rocket engine, and t6 is usually 0.3~0.35s). If △θ<θ1, the real-time pitch angle θ is further determined. 实时 , if θ 实时 ≥ threshold θ2, then θ 实时 Obviously, it meets the subsequent conventional parachute launch requirements and enters the separation parachute launch procedure when T2 ≥ t6 (t6 is the time when the rocket engine finishes working, which is determined according to the performance of the rocket engine, and t6 is usually 0.3 to 0.35s). If θ 实时 <θ2, the parachute will be launched in advance after a delay of t4 and will separate after the rocket engine has finished working;

[0038] Among them, the determination threshold θ1 of the pitch angle increment △θ of the remaining working time of the rocket engine is taken as the pitch angle between the seat parachute shooting direction and the seat ejection direction, that is, θ1 = θ 射伞 -θ 弹射 , θ1 is usually 25°~35°; the real-time pitch angle after ejection is θ 实时 The principle of selecting the judgment threshold θ2 is: to ensure that the seat pitch angle is not less than 0° when the rocket engine is finished working, θ2 is usually -15°~-5°; the delay time t4 is when the side parachute conditions are not met, the head-up angle acceleration provided by the rocket engine is large, △θ and θ 实时 The delayed parachute launch time is not enough to meet the subsequent conventional parachute launch requirements. Its value is comprehensively evaluated based on the trajectory height performance of the corresponding person-chair mass. It is usually 0.14 to 0.17 seconds after the rocket engine starts working. Therefore, the value of t4 is 0.14-(t2+t3) to 0.17-(t2+t3)s.

[0039] 4.2) When α z实时 <α1: the nose-up angular acceleration provided by the rocket engine is small, and further determination of ω z实时 , if ω z实时 ≥ threshold ω2, then ω z实时 Obviously, it meets the subsequent conventional parachute launch requirements and enters the separation parachute launch procedure when T2 ≥ t6 (t6 is the time when the rocket engine finishes working, which is determined according to the performance of the rocket engine, and t6 is usually 0.3 to 0.35s). If ω z实时 <ω2, the parachute will be launched in advance 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 cabin z实时The principle of selecting the judgment threshold ω2 is to ensure that the pitch angle increment is not less than the pitch angle (θ 射伞 -θ 弹射 ), ω2 is usually 100-200° / s; the delay time t5 is when the side parachute conditions are not met, the head-up angular acceleration provided by the rocket engine is small, ω z实时 The delayed parachute launch time is not enough to meet the subsequent conventional parachute launch requirements. Its value is comprehensively evaluated based on the trajectory height performance of the corresponding person-chair mass. The parachute launch time is usually 0.18 to 0.2 seconds after the rocket engine works. Therefore, the value of t5 is 0.18-(t2+t3) to 0.2-(t2+t3)s.

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

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

[0043] 2) After the rocket engine has finished working, that is, when T2 ≥ t6, the separation parachute program is entered. t6 is the time when the rocket engine has finished working. The value is determined according to the performance of the rocket engine. t6 is usually 0.3 to 0.35s.

[0044] Embodiment 2

[0045] This embodiment provides a control system for a rocket ejection seat during low-altitude, low-speed and level flight ejection, including an electronic program controller installed on the seat, which collects real-time speed, altitude and attitude data of the seat after power-on, and when ejection is started under low-altitude, low-speed and level flight conditions, controls the rocket engine, separated explosive bombs and parachute gun bullets according to the real-time attitude data to complete corresponding actions using the control method of the first embodiment. In this embodiment, the electronic program controller includes a MEMS inertial measurement module and multiple control boards, and adopts a DSP digital signal processing system; its MEMS inertial measurement module is used to collect real-time speed, altitude and angles, angular velocity and angular velocity of heading, pitch and roll in three axes; its control board includes a processing chip, a general I / O port, a general timer, a power-on reset and monitoring circuit, an A / D converter, a control start signal circuit, an ignition module, a non-volatile memory, etc., which are used to receive, process and send electrical signals.

[0046] Application examples:

[0047] A new ejection seat is equipped with an electronic program controller that can interact with aircraft signals, sense seat speed, altitude and attitude in real time, and output electric ignition according to the set control logic program. According to the simulation and test verification of the seat, the control parameter values ​​are now specified as follows: angle judgment threshold θ1 = 30°, θ2 = -10°, angular velocity judgment threshold ω1 = 60° / s, ω2 = 100° / s; angular acceleration judgment threshold α1 = 400° / s 2 ; The time judgment thresholds are t1 = 0.2s, t2 = 0.03s, t3 = 0.06s, t4 = 0.06s, t5 = 0.09s, and t6 = 0.3s. In addition, the seat ejection performance simulation calculation was carried out. Under the zero-zero working condition, the minimum safe ejection height of passengers of large, medium and small weights is 0m, which can meet the safety rescue height requirements. In addition, a comprehensive ejection test under zero-zero conditions was carried out. A heavy dummy was used to simulate the pilot. The test results show that when the parachute was launched, the pitch angle was -25°, and the direction of the parachute was toward the rear along the course. After the parachute was launched, the pitch angle of the human-chair system continued to decrease due to the recoil of the parachute launching bullet until the rocket engine finished working. With the deceleration pulling force of the life-saving parachute, the pitch posture of the human-chair turned to raising its head. At this time, the parachute rope had been straightened and began to inflate, and the human-chair moved in front of the life-saving parachute canopy. After the separation explosive bomb worked, the dummy was decelerated and pulled out of the seat basin by the life-saving parachute. During the whole process, the life-saving parachute was always behind the human chair and did not interfere with the movement direction of the human chair, thus achieving the design goal of safe lifesaving.

[0048] The present application can avoid the phenomenon of "people chasing the parachute" and avoid entanglement between the crew and the parachute rope or canopy of the life-saving parachute under the condition of low-altitude, low-speed and level-flight ejection, thereby ensuring the life-saving safety under the condition of low-altitude, low-speed and level-flight ejection, and can adapt to crew members of different weights.

[0049] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

Claims

1. A control method for a rocket ejection seat during low-altitude, low-speed and level flight ejection, characterized in that: Under the condition of low-altitude, low-speed and level flight ejection of the seat, the real-time attitude data of the seat is analyzed to predict the trend of future seat attitude changes and the pitch adjustment capability of the rocket engine, thereby controlling the timing of parachute shooting: if it is judged that the rocket engine can meet the pitch direction correction requirements, the parachute is controlled to be shot after the rocket engine is finished working; if it is judged that the rocket engine cannot meet the pitch direction correction requirements and will affect the safety of parachute shooting, the parachute is controlled to be shot in advance when the rocket engine has not finished working and the seat attitude meets the requirements for safe parachute shooting, thereby avoiding the parachute shooting direction in front of the movement of the human chair after the rocket engine is finished working, and using the head-up torque generated by the deceleration of the lifesaving parachute to suppress the continuous head-down effect of the seat.

2. The control method of the rocket ejection seat during low-altitude, low-speed and level flight ejection as claimed in claim 1, characterized in that: First determine the absolute value of the roll angular velocity at the time of ejection start |ω x启动 |, if |ω x启动 |<threshold ω1, the side parachute shooting condition is not met and the control branch 1 of the early parachute shooting is entered. If |ω x启动 |≥ω1, the side parachute shooting condition is met and the control branch 2 of the conventional parachute shooting is entered; In branch line 1: first control the rocket engine to work at the moment of seat exit, then delay t2 to wait for the rocket engine to work stably, and then adjust the pitch angle velocity ω according to the real-time z实时 Moving average calculation of pitch angle acceleration α z实时 , and then delay t3 to obtain sufficient data for subsequent judgment. z实时 ≥ threshold α1, the nose-up acceleration provided by the rocket engine is large, and the pitch angle increment △θ of the remaining working time of the rocket engine is continued to be calculated. If △θ ≥ threshold θ1, then △θ obviously meets the subsequent conventional parachute shooting requirements, and the separation parachute shooting program is entered after the rocket engine is finished working. If △θ < θ1, the real-time pitch angle θ is further determined. 实时 , if θ 实时 ≥ threshold θ2, then θ 实时 Obviously, it meets the subsequent conventional parachute shooting requirements and enters the separation parachute shooting procedure after the rocket engine is finished working. If θ 实时 <θ2, the parachute will be launched in advance after a delay of t4 and will separate after the rocket engine has finished working; when α z实时 When α<1, the nose-up angular acceleration provided by the rocket engine is small, and further determination of ω z实时 , if ω z实时 ≥ threshold ω2, then ω z实时 Obviously, it meets the subsequent conventional parachute shooting requirements and enters the separation parachute shooting procedure after the rocket engine is finished working. z实时 <ω2, the parachute will be launched in advance 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 work when the seat exits the cabin, and then enter the separation parachute shooting program after the rocket engine finishes working.

3. The control method of the rocket ejection seat during low-altitude, low-speed and level flight ejection as claimed in claim 2 is characterized in that: The absolute value of the rolling angular velocity at the time of ejection start |ω x启动 The principle of selecting the value of the judgment threshold ω1 of | is: to ensure that within the time range from the ejection of the lifesaving parachute to the straightening of the parachute rope, the roll angle change of the seat exceeds the half value θ of the cone envelope angle formed by the canopy and the pilot after the lifesaving parachute is fully inflated 伞 / 2.

4. The control method of the rocket ejection seat during low-altitude, low-speed and level flight ejection as claimed in claim 2, characterized in that: The method of controlling the rocket engine to work at the time of seat exiting the cabin is as follows: the ejection start switch K1 and the seat exiting cabin start switch K2 are set, the seat ejection start time is when K1 works, at this moment T1=0s, and the seat exiting cabin time is when K2 works, at this moment T2=0s; The working time of the rocket engine is taken as the working time of K2, or T1≥t1 is taken as the working time of the rocket engine, and t1 is the time from the seat ejection start to the exit from the cabin.

5. The control method of the rocket ejection seat during low-altitude, low-speed and level flight ejection as claimed in claim 2, characterized in that: The delay time t2 is the time it takes for the thrust to grow from generation to stability after the rocket engine is ignited; the delay time t3 is the time for the moving average calculation of the pitch angle acceleration, and t3 is no less than 3 times the data refresh cycle.

6. The control method of the rocket ejection seat during low-altitude, low-speed and level flight ejection as claimed in claim 2, characterized in that: Pitch acceleration α after ejection z实时 The principle of selecting the value of the judgment threshold α1 is to ensure that when the rocket engine is finished working, the pitch angle increment of the seat parachute shooting direction during the working time of the rocket engine is not less than 0° or not less than the half value θ of the cone envelope angle formed by the canopy and the pilot after the lifesaving parachute is fully opened 伞 / 2.

7. The control method of the rocket ejection seat during low-altitude, low-speed and level flight ejection as claimed in claim 2, characterized in that: The determination threshold θ1 of the pitch angle increment △θ of the remaining working time of the rocket engine is taken as the pitch angle between the seat parachute direction and the seat ejection direction, that is, θ1 = θ 射伞 -θ 弹射 ; Real-time pitch angle θ after ejection 实时 The principle for selecting the value of the judgment threshold θ2 is to ensure that the seat pitch angle is not less than 0° when the rocket engine finishes working.

8. The control method of the rocket ejection seat during low-altitude, low-speed and level flight ejection as claimed in claim 2, characterized in that: Real-time pitch angular velocity ω after ejection z实时 The principle for selecting the value of the judgment threshold ω2 is: ensure that under the pitch angle acceleration α1, the pitch angle increment is not less than the pitch angle between the seat parachute shooting direction and the seat ejection direction.

9. The control method of the rocket ejection seat during low-altitude, low-speed and level flight ejection as claimed in claim 2, characterized in that: The delay time t4 does not meet the side parachute conditions, the rocket engine provides a large head-up angular acceleration, △θ and θ 实时 The delayed parachute shooting time is not enough to meet the subsequent conventional parachute shooting requirements. The delay time t5 does not meet the side parachute shooting conditions, the head-up angle acceleration provided by the rocket engine is small, and ω z实时 The delayed parachute shooting time is not enough to meet the subsequent conventional parachute shooting requirements. The values ​​of both are comprehensively evaluated based on the trajectory height performance of the corresponding person-chair mass.

10. A control system for a rocket ejection seat during low-altitude, low-speed and level flight ejection, comprising an electronic program 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, and when the ejection is detected under low-altitude, low-speed and level flight conditions, it uses the control method for low-altitude, low-speed and level flight ejection of the rocket ejection seat as described in any one of claims 1 to 9 to control the rocket engine, separation explosive bomb and parachute gun bullet according to the real-time attitude data to complete the corresponding action.

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