Extreme eccentric distance identification method and ejection control method and device

Abstract

The invention discloses an extreme eccentric distance identification method and an ejection control method and device.The identification method comprises the steps that the pitch angle speed within a certain time after a rocket ejection seat leaves a cabin and a rocket engine is ignited is collected at high updating frequency, the pitch angle acceleration is synchronously updated and calculated, then the current average pitch angle acceleration is obtained through moving average, and the current average pitch angle acceleration is calculated; therefore, acceleration interference generated by first-level power within a certain time from cabin leaving to rocket engine ignition is removed, then the current average pitch angle acceleration is compared with a threshold value, and if the current average pitch angle acceleration exceeds the threshold value, the extreme eccentric distance is identified. According to the recognition method, the extreme eccentricity can be accurately recognized based on the angular acceleration under the condition that acceleration interference generated by first-stage power is avoided, and when the ejection control method and device are used for recognizing the extreme eccentricity, the problem that the life-saving performance is reduced due to percussion of a posture adjusting rocket is solved.

Description

Technical Field

[0001] The invention belongs to the field of aviation lifesaving, and in particular relates to an extreme eccentricity identification method and an ejection control method and device. Background Art

[0002] In order to accommodate passengers of different weights and heights, the seat basin of the rocket ejection seat can be adjusted up and down. When different passengers are riding, the weight center of gravity of the person-seat-parachute system is different. The primary power of the rocket ejection seat is the ejector, which is used to disconnect the rocket ejection seat from the aircraft and eject it out of the cabin. The secondary power is the rocket engine, which is used to push the rocket ejection seat to continue to rise to a certain height. The thrust axis of the secondary power of the rocket ejection seat is fixed, while the weight center of gravity of the person-seat-parachute system is different when different occupants ride on it. Therefore, the secondary power of the rocket ejection seat will have a certain degree of eccentricity. Generally, the distance between the thrust line of the rocket engine and the projection of the weight center of gravity in the XOY plane of the person-seat-parachute system is defined as the eccentricity. According to the simulation calculation of the distribution of the weight center of gravity of the occupants, it can be known that the range of eccentricity is relatively wide, ranging from more than ten millimeters to more than fifty millimeters. Therefore, the eccentricity corresponding to different occupants is different, resulting in angular motion of the person-seat-parachute system under the action of the secondary power after leaving the cabin, and the corresponding values ​​of different occupants are quite different. In order to allow the rocket ejection seat to obtain a higher height from the ground for better life-saving, it is necessary to improve the utilization efficiency of the rocket engine, increase linear motion and suppress angular motion.

[0003] After the rocket ejection seat ejects from the aircraft and enters the "free flight" phase, in addition to using the rocket engine to provide secondary power, it will also use a number of attitude adjustment rockets (such as Figure 1 As shown in the figure, there are generally head-up rockets and head-down rockets located on the center line of the rocket ejection seat, and roll attitude rockets located on both sides of the rocket ejection seat) to control the attitude of the rocket ejection seat. Each attitude adjustment rocket uses a pulse rocket, and the angle and angular velocity feedback method is used to control the ignition timing of the attitude adjustment rocket at each position, so as to achieve the purpose of improving the life-saving performance.

[0004] At present, due to the large range of eccentricity, the angular velocity generated by the rocket engine on the person-chair-parachute system during emergency ejection of different crew members varies greatly, and the rocket engine has a short working time, the angular velocity generated by the attitude adjustment rocket is large, and the attitude adjustment time is very short. When different crew members use the rocket ejection seat, only the angle and angular velocity feedback method cannot adapt well to different eccentricities. The key is that it cannot distinguish between extreme eccentricities. In the case of extreme eccentricity, firing the attitude adjustment rocket will cause a large overshoot and even lead to a decrease in life-saving performance. Summary of the invention

[0005] In view of the problem that the current attitude adjustment method cannot distinguish the extreme eccentricity, resulting in the possibility of deterioration of life-saving performance when firing the attitude adjustment rocket under extreme eccentricity conditions, the purpose of the present invention is to provide an extreme eccentricity identification method, and an ejection control method based on the above-mentioned extreme eccentricity identification method, and an ejection control device based on the above-mentioned ejection control method. The identification method can accurately identify the extreme eccentricity based on angular acceleration while avoiding the acceleration interference generated by the primary power. The ejection control method and device can avoid the problem of deterioration of life-saving performance caused by firing the attitude adjustment rocket when identifying the extreme eccentricity.

[0006] The technical solution adopted by the present invention is: A method for identifying extreme eccentricity, which collects the pitch velocity of the rocket ejection seat within a certain period of time from the time the ejection seat leaves the cabin to the time the rocket engine is ignited at a high update frequency, and synchronously updates the calculated pitch acceleration, and then obtains the current average pitch acceleration through sliding average, thereby removing the acceleration interference generated by the first-stage power within a certain period of time from the time the ejection seat leaves the cabin to the time the rocket engine is ignited, and then compares the current average pitch acceleration with a threshold value, and if it exceeds the threshold value, it is identified as extreme eccentricity.

[0007] Preferably, the pitch angular velocity within a certain period of time from the ejection seat leaving the cabin to the ignition of the rocket engine is collected with an update frequency of T0, T0=20ms.

[0008] Preferably, the pitch angular velocity within T1 after the rocket ejection seat leaves the cabin to the ignition of the rocket engine is collected, T1=100ms.

[0009] Preferably, the threshold value A is obtained by performing multiple emergency ejection tests on occupants with different weight centers of gravity, and by counting and processing the angular velocity value data in the tests.

[0010] Preferably, the time when the ejection seat is ejected and released is used as the time 0. When the exit moment is reached, the pitch angular velocity is collected at a frequency of one beat with time T0. The latest pitch angular velocity is ω z (n), the pitch angular velocity of the previous shot is ω z (n-1), then the latest pitch angular acceleration (n) = (ω z (n)-ω z (n-1)) / T0, each time the pitch angular velocity is collected, the pitch angular acceleration is calculated once, the latest six pitch angular acceleration results are saved, and the average of the three consecutive pitch angular accelerations is calculated. , which is the current average pitch acceleration (n), when reaching a certain time T1 after the rocket engine ignition, compare the current average pitch angle acceleration (n) and threshold value A, if the current average pitch angle acceleration (n)>A, it is identified as extreme eccentricity.

[0011] An ejection control method, within a certain time T0 after the rocket ejection seat leaves the cabin and after the rocket engine ignites, the above-mentioned extreme eccentricity recognition method is used. If the extreme eccentricity is recognized, the head-up rocket will not be ignited to avoid the degradation of life-saving performance due to excessive change in pitch angle; and the time when the rocket ejection seat is ejected and released and starts to move is used as time 0, the current speed V and the current height H after the rocket ejection seat leaves the cabin are collected, and the current speed V, the current height H and the timing time T are compared with the preset value. If the current speed V ≤ the preset speed V 预设 And the current height H ≤ preset height H 预设 , or, the timing time T ≥ the preset time T 预设 , the rocket ejection seat enters the separation parachute program, otherwise it continues to wait until the preset speed V is met at the same time. 预设 and preset height H 预设 , the rocket ejection seat enters the separation parachute program.

[0012] Preferably, within a certain time T0 after the rocket ejection seat exits the cabin and after the rocket engine ignites, if the pitch angle θ is any value between -90° to -30° and 30° to 90°, and the current speed V is any value between 0 km / h and 300 km / h, it is time for the head-up rocket to ignite.

[0013] An ejection control device is used to control a rocket ejection seat with pitch attitude adjustment capability, comprising a data acquisition module and a control module; the data acquisition module can acquire three-dimensional attitude angle, three-dimensional angular velocity, speed and altitude data of a person-chair system; the control module can receive data from the data acquisition module and adopt the strategy of the above-mentioned ejection control method for control.

[0014] Preferably, for the coordinate system of the person-chair system, the coordinate origin O is located at the center of mass of the person-chair system, the OX axis points to the aircraft heading, the OY axis points to the sky in the longitudinal symmetry plane of the person-chair system, and the OZ axis points to the right side of the heading direction of the person-chair system according to the right-hand rule. The three-axis attitude angle includes the yaw angle ψ, the pitch angle θ, and the roll angle γ, and the three-axis angular velocity includes the yaw angular velocity ω y , pitch angular velocity ω z 、Roll angular velocity ω x .

[0015] The beneficial effects of the present invention are: The identification method can accurately identify the extreme eccentricity based on angular acceleration while avoiding the acceleration interference generated by the first-stage power. The ejection control method and device can avoid the problem of reduced life-saving performance caused by firing the attitude adjustment rocket when the extreme eccentricity is identified. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the installation of the rocket engine and the attitude adjustment rocket on the rocket ejection seat, wherein a) is a side view, and b) is a front view; in the figure: 1 is a head-up rocket, 2 is a rocket engine, 3 is a head-down rocket, 4 is a rolling attitude rocket, L1 is the distance from the head-up rocket to the center of mass of the person-chair system in the XY plane, L2 is the distance from the head-down rocket to the center of mass of the person-chair system in the XY plane, L3 is the distance from the rolling attitude rocket to the center of mass of the person-chair system in the XY plane, θ1 is the inclination angle of the seat back frame, and θ2 is the angle between the rocket engine and the seat back frame.

[0017] Figure 2 This is the pitch angular velocity curve corresponding to different eccentricities.

[0018] Figure 3 The figure is the calculation result of the three-beat average value of the pitch angle acceleration corresponding to different eccentricities. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0020] Embodiment 1 This embodiment provides a method for identifying extreme eccentricity: The pitch angular velocity within a certain period of time from the time the rocket ejection seat leaves the cabin to the time the rocket engine 2 is ignited is collected at a high update frequency, and the pitch angular acceleration is calculated and updated synchronously. The current average pitch angular acceleration is then obtained through sliding average, thereby removing the acceleration interference generated by the first-stage power within a certain period of time from the time the seat leaves the cabin to the time the rocket engine 2 is ignited. The current average pitch angular acceleration is then compared with the threshold value. If the threshold value is exceeded, it is identified as an extreme eccentricity.

[0021] Specifically, the time when the ejection seat is ejected and released is taken as time 0. When the exit time is reached (T ≥ 0.18s), the pitch angular velocity is collected at a frequency of one beat with time T0. The latest pitch angular velocity is ω z (n), the pitch angular velocity of the previous shot is ω z (n-1), then the latest pitch angular acceleration (n) = (ω z (n)-ω z(n-1)) / T0, each time the pitch angular velocity is collected, the pitch angular acceleration is calculated once, the latest six pitch angular acceleration results are saved, and the average of the three consecutive pitch angular accelerations is calculated. , which is the current average pitch acceleration (n), when a certain time T1 is reached after the ignition of rocket engine 2, compare the current average pitch angle acceleration (n) and threshold value A, if the current average pitch angle acceleration (n)>A, it is identified as extreme eccentricity.

[0022] In this embodiment, preferably: the pitch angular velocity within a certain period of time from the ejection seat leaving the cabin to the ignition of the rocket engine 2 is collected with an update frequency of T0, T0=20ms; the pitch angular velocity within T1 after the ejection seat leaving the cabin to the ignition of the rocket engine 2 is collected, T1=100ms; Figure 2 and Figure 3 As shown, the threshold value A is obtained by performing multiple emergency ejection tests on occupants with different weight centers of gravity, and by counting and processing the angular velocity value data in the tests.

[0023] This identification method can accurately identify extreme eccentricity based on angular acceleration while avoiding the acceleration interference generated by the primary power.

[0024] Embodiment 2 This embodiment provides a method for controlling ejection: Within a certain time T0 after the rocket ejection seat leaves the cabin and after the rocket engine 2 ignites, the above-mentioned extreme eccentricity recognition method is used. If it is recognized as an extreme eccentricity, the head-up rocket 1 will not ignite to avoid a large change in the pitch angle causing a decrease in life-saving performance; In addition, the time when the rocket ejection seat is ejected and released and starts to move is taken as time 0, and the current speed V and current altitude H after the rocket ejection seat leaves the cabin are collected. The current speed V, current altitude H and timing time T are compared with the preset values. If the current speed V ≤ the preset speed V 预设 And the current height H ≤ preset height H 预设 , or, the timing time T ≥ the preset time T 预设 , the rocket ejection seat enters the separation parachute program, otherwise it continues to wait until the preset speed V is met at the same time. 预设 and preset height H 预设 , the rocket ejection seat enters the separation parachute program.

[0025] In this embodiment, preferably: within a certain time T0 after the rocket ejection seat exits the cabin and after the rocket engine 2 is ignited, if the pitch angle θ is any value between -90° to -30° and 30° to 90°, and the current speed V is any value between 0 km / h and 300 km / h, then it is the time for the head-up rocket 1 to ignite, and then the specific ignition control strategy (ignition start and stop timing) is selected according to the specific situation of the posture.

[0026] This ejection control method can avoid the problem of reduced life-saving performance caused by firing the attitude-adjusting rocket when extreme eccentricity is identified.

[0027] Embodiment 3 This embodiment provides an ejection control device for controlling a rocket ejection seat with pitch attitude adjustment capability, including a data acquisition module and a control module: The data acquisition module can collect the three-dimensional attitude angle, three-dimensional angular velocity, speed and height data of the person-chair system; The control module can receive the data from the data acquisition module and adopt the strategy of the above ejection control method for control.

[0028] For the coordinate system of the person-chair system, the coordinate origin O is located at the center of mass of the person-chair system, the OX axis points to the aircraft heading, the OY axis points to the sky in the longitudinal symmetry plane of the person-chair system, and the OZ axis points to the right side of the heading direction of the person-chair system according to the right-hand rule. The three-axis attitude angles include the yaw angle ψ, the pitch angle θ, and the roll angle γ. The three-axis angular velocity includes the yaw angular velocity ω y , pitch angular velocity ω z 、Roll angular velocity ω x .

[0029] The ejection control device can avoid the problem of reduced life-saving performance caused by firing the attitude adjustment rocket when extreme eccentricity is identified.

[0030] Taking a certain type of rocket ejection seat as an example, according to the calculation of a small weight occupant, under the conditions of a pitch angle of -50°, a roll angle of 60°, a speed of 150 km / h, and a sinking rate of -5m / s, if the present invention is not adopted, the minimum safe height of the seat is 16.1m. After adopting the present invention, the minimum safe height value is 10m. Therefore, the present invention can improve the life-saving performance of the seat under extreme eccentricity and pitch angle conditions. The above-described embodiments are part of the embodiments of this application, not all of them.

[0031] 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 selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

Claims

1. A method for identifying extreme eccentricity, characterized in that: The pitch angular velocity within a certain period of time from the time the rocket ejection seat exits the cabin to the time the rocket engine is ignited is collected at a high update frequency, and the pitch angular acceleration is calculated and updated synchronously. The current average pitch angular acceleration is then obtained through sliding average, thereby removing the acceleration interference generated by the first-stage power within a certain period of time from the time the seat exits the cabin to the time the rocket engine is ignited. The current average pitch angular acceleration is then compared with the threshold value. If the threshold value is exceeded, it is identified as an extreme eccentricity.

2. The extreme eccentricity identification method according to claim 1, characterized in that: The pitch angular velocity is collected within a certain period of time from the ejection seat leaving the cabin to the ignition of the rocket engine with an update frequency of T0, T0=20ms.

3. The extreme eccentricity identification method according to claim 1, characterized in that: The pitch angular velocity is collected from the time the rocket ejection seat leaves the cabin to the time the rocket engine is ignited, T1=100ms.

4. The extreme eccentricity identification method according to claim 1, characterized in that: The threshold value A is obtained by performing multiple emergency ejection tests on occupants with different weights and centers of gravity, and by statistically analyzing and processing the angular velocity data in the tests.

5. The extreme eccentricity identification method according to any one of claims 1 to 4, characterized in that: The time when the ejection seat is ejected and released is taken as time 0. When the exit moment is reached, the pitch angular velocity is collected at a frequency of one beat at time T0. The latest pitch angular velocity is ω z (n), the pitch angular velocity of the previous shot is ω z (n-1), then the latest pitch angular acceleration (n) = (ω z (n)-ω z (n-1)) / T0, each time the pitch angular velocity is collected, the pitch angular acceleration is calculated once, the latest six pitch angular acceleration results are saved, and the average of the three consecutive pitch angular accelerations is calculated. , which is the current average pitch acceleration (n), when reaching a certain time T1 after the rocket engine ignition, compare the current average pitch angle acceleration (n) and threshold value A, if the current average pitch angle acceleration (n)>A, it is identified as extreme eccentricity.

6. A method for ejection control, characterized in that: Within a certain time T0 after the rocket ejection seat leaves the cabin and after the rocket engine is ignited, the extreme eccentricity recognition method as described in any one of claims 1 to 5 is adopted. If it is recognized as an extreme eccentricity, the head-up rocket will not ignite to avoid a decrease in life-saving performance due to excessive changes in the pitch angle; and, the time when the rocket ejection seat is ejected and released and starts to move is used as time 0, the current speed V and current altitude H after the rocket ejection seat leaves the cabin are collected, and the current speed V, current altitude H and timing time T are compared with preset values. If the current speed V ≤ preset speed V 预设 And the current height H ≤ preset height H 预设 , or, the timing time T ≥ the preset time T 预设 , the rocket ejection seat enters the separation parachute program, otherwise it continues to wait until the preset speed V is met at the same time. 预设 and preset height H 预设 , the rocket ejection seat enters the separation parachute program.

7. The ejection control method according to claim 6, characterized in that: Within a certain time T0 after the rocket ejection seat leaves the cabin and after the rocket engine ignites, if the pitch angle θ is any value between -90°~-30° and 30°~90°, and the current speed V is any value between 0km / h~300km / h, then it is time for the head-up rocket to ignite.

8. An ejection control device, characterized in that: Used to control a rocket ejection seat with pitch attitude adjustment capability, comprising a data acquisition module and a control module; the data acquisition module can collect three-way attitude angle, three-way angular velocity, speed and altitude data of the person-chair system; the control module can receive data from the data acquisition module and adopt the strategy of the ejection control method as described in claim 6 or 7 for control.

9. The ejection control device according to claim 8, characterized in that: For the coordinate system of the person-chair system, the coordinate origin O is located at the center of mass of the person-chair system, the OX axis points to the aircraft heading, the OY axis points to the sky in the longitudinal symmetry plane of the person-chair system, and the OZ axis points to the right side of the heading direction of the person-chair system according to the right-hand rule. The three-axis attitude angles include the yaw angle ψ, the pitch angle θ, and the roll angle γ. The three-axis angular velocity includes the yaw angular velocity ω y , pitch angular velocity ω z , rolling angular velocity ω x .

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