Throwing safety control method for drag parachute of medium-large aircraft

Abstract

The invention discloses a throwing safety control method for a drag parachute of a medium-large aircraft, and a drag parachute control system for executing the throwing safety control method comprises a control unit, a drag parachute control panel, a power distribution unit, a drag parachute releasing microswitch and an ignition cap seat connected with the power distribution unit, the drag parachute control panel is used for sending a parachute releasing signal; the method comprises the following steps: step 1, receiving a parachute releasing signal sent by a drag parachute control panel and a corresponding signal sent by external equipment or a part crosslinked with a drag parachute control system through a control unit; 2, the control unit judges whether the parachute placing condition is met or not based on internal control logic according to the received signals, and when it is judged that the parachute placing condition is met, the power distribution unit is controlled to be connected with a parachute placing electric detonator in an ignition cap base so as to open a drag parachute cabin door and implement parachute placing operation; step 3, after the drag parachute cabin door is opened, pressing and switching on a drag parachute releasing microswitch, and generating a parachute releasing signal by the drag parachute releasing microswitch; 4, the control unit receives a parachute throwing signal sent by the drag parachute control panel and a ground speed signal sent by inertial navigation equipment, judges whether a parachute throwing condition is met or not based on internal logic of the parachute throwing signal, controls the power distribution unit to switch on a parachute throwing electric detonator in an ignition cap seat and controls a parachute hook of the drag parachute to be opened when judging that the parachute throwing condition is met, and therefore the parachute throwing condition is met. The drag parachute is separated from the parachute hook, and parachute throwing operation is completed.

Description

Technical Field

[0001] The present invention relates to, but is not limited to, the technical field of aircraft drag parachute control systems, and in particular to a method and a test method for safely controlling the release of a drag parachute for a medium-to-large aircraft. Background Art

[0002] The drag parachute is a portable air-powered parachute device made of a flexible fabric installed at the tail of an aircraft. It increases aerodynamic drag and assists wheel braking to quickly decelerate the aircraft, thereby shortening the landing runway distance. The use of drag parachutes in the field of military aircraft is very common. Since military aircraft must be able to adapt to various combat environments, especially when airport runway conditions are limited, drag parachutes can greatly shorten the landing distance of military aircraft.

[0003] When the aircraft returns to the landing field after completing training and combat missions, opening the drag parachute can immediately generate a large amount of air resistance to help decelerate. When the aircraft fails to take off, the drag parachute can also be released to abort the takeoff. In special circumstances, such as wheel brake failure, no flap function, overspeed landing or landing in adverse conditions such as wet and icy conditions, the drag parachute can be opened to generate very large aerodynamic resistance, that is, to provide deceleration force to help the aircraft decelerate quickly. It can be seen that drag parachute deceleration is an important way for aircraft to achieve deceleration, and can work in conjunction with other deceleration methods such as wheel brake deceleration and flap control deceleration to ensure the safe flight of the aircraft. However, the drag parachute deceleration method has the following problems in actual application: accidental release or throwing of the drag parachute due to accidental touch of the switch, the parachute cannot be reliably released and thrown away due to problems with the control line or control components, and the parachute is pulled and damaged due to improper control, affecting the safety of the aircraft. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned technical problems. The embodiments of the present invention provide a method for safely controlling the release of a drag parachute for medium and large aircraft, so as to solve the problems of the drag parachute deceleration mode of existing aircraft, such as the accidental release or throwing out of the drag parachute due to accidental touching of the switch, the inability to reliably release and throw away the parachute due to problems with the control line or control components, and the parachute being pulled and damaged due to improper control, affecting the safety of the aircraft.

[0005] Technical solution of the present invention: The embodiment of the present invention provides a method for safely controlling the release of a drag parachute of a medium-to-large aircraft. The drag parachute control system for executing the release safety control method comprises: a control unit, a drag parachute control panel connected to the control unit, a power distribution unit, a drag parachute release micro switch, and a pyrotechnic cap seat connected to the power distribution unit, wherein the drag parachute control panel is used to send a parachute release signal; the method comprises:

[0006] Step 1, receiving, through a control unit, a parachute release signal sent by a parachute control panel, and a corresponding signal sent by an external device or component interconnected with the parachute control system;

[0007] Step 2: The control unit determines whether the parachute release condition is met based on the internal control logic according to the received signals. When it is determined that the parachute release condition is met, the control unit controls the power distribution unit to connect the parachute release electric squib in the ignition cap seat to open the drag parachute door and implement the parachute release operation.

[0008] Step 3: After the drag parachute door is opened, the drag parachute release micro switch is pressed and turned on, and the drag parachute release micro switch generates a parachute release signal;

[0009] Step 4, the control unit receives the parachute jettison signal from the drag parachute control panel and the ground speed signal from the inertial navigation device, and determines whether the normal parachute jettison conditions are met based on its internal logic. When it is determined that the normal parachute jettison conditions are met, the control unit controls the power distribution unit to connect the parachute jettison electric squib in the ignition cap seat, controls the drag parachute hook to open, and allows the drag parachute to fall off the hook, completing the parachute jettison operation.

[0010] Optionally, in the above-mentioned method for safely controlling the release of a drag parachute for a medium-to-large aircraft, the external devices or components interconnected by the drag parachute control system include:

[0011] Inertial navigation equipment, used to provide ground speed signals;

[0012] The left and right main landing gear lowering micro switches are used to send out the left and right landing gear lowering signals respectively;

[0013] A radio altimeter, used to send out altitude signals;

[0014] The main landing gear ground switch is used to send out a signal that the main landing gear has wheel load.

[0015] Optionally, in the above-mentioned method for safely controlling the release of a drag parachute for a medium-to-large aircraft, the judgment logic for determining whether the release condition is met is that the following conditions are met at the same time:

[0016] ① The “release” switch on the left or right drag parachute control panel is turned on;

[0017] ② Ground speed ≤ 230 km / h;

[0018] ③The left main landing gear or right main landing gear lowering micro switch is turned on;

[0019] ④ The low-altitude radio altimeter shows an altitude of less than 3m;

[0020] ⑤The main landing gear has a wheel load signal "hanging"

[0021] Optionally, in the above-mentioned method for safely controlling the release of a drag parachute for a medium-to-large aircraft, after step 3, the method further includes:

[0022] When the drag parachute release micro switch is turned on, the control unit determines whether the emergency parachute release condition is met based on the internal control logic by receiving various signals. When it is determined that the emergency parachute release condition is met, the control unit controls the power distribution unit to connect the parachute release electric squib in the ignition cap seat, controls the drag parachute hook to open, and removes the drag parachute from the hook, thereby completing the parachute release operation.

[0023] The judgment logic of the emergency parachute throwing condition is: when it is judged that any one of the five conditions in the parachute throwing condition is not met, it is judged that the emergency parachute throwing condition is met.

[0024] Optionally, in the above-mentioned method for safely controlling the release of a drag parachute for a medium-to-large aircraft, the judgment logic for satisfying the release condition is that at least one condition is satisfied:

[0025] Receiving a "parachute jettison" switch-on signal from the left parachute control panel or the right parachute control panel; or

[0026] Ground speed ≤40km / h.

[0027] Optionally, in the above-mentioned method for safely controlling the release of a drag parachute for a medium-to-large aircraft, it is characterized in that the drag parachute control panel includes left and right drag parachute control panels respectively arranged for the left and right pilots to independently control the release and release of the drag parachute;

[0028] Each drag parachute control panel is provided with a "parachute release" switch and a "parachute throwing" switch; wherein the "parachute throwing" switch is provided with a protective cover to prevent the pilot from accidentally touching the "parachute throwing" switch; the "parachute release" switch is arranged in a sunken installation form, the bottom plate of the drag parachute control panel forms a groove at the position of the "parachute release" switch, and the "parachute release" switch is embedded in the groove, so that the horizontal plane of the "parachute release" switch is lower than the light guide plate;

[0029] A parachute releasing signal light is integrated on the top of the "parachute releasing" switch, so that the "parachute releasing" switch has the functions of parachute releasing control and parachute releasing signal light indication; and the parachute releasing signal light is cross-linked with the drag parachute releasing micro switch, which is used to light up the parachute releasing signal light on the "parachute releasing" switch after the drag parachute box door is opened and the drag parachute releasing micro switch is pressed, to indicate that the drag parachute has been released.

[0030] Optionally, in the above-mentioned method for safely controlling the release of a drag parachute for a medium-to-large aircraft, the ignition cap seat is configured as a double-redundant parachute release ignition cap seat and a double-redundant parachute release ignition cap seat, and an electric squib is provided in the channel of each ignition cap seat;

[0031] When one of the parachute release ignition caps is energized, the electric squib inside it is energized and explodes, thereby opening the drag parachute box door and releasing the drag parachute under the action of weight;

[0032] When one of the parachute ignition cap seats is energized, the electric squib inside it is energized and explodes, controlling the drag parachute hook to open, allowing the drag parachute to fall off the hook and be discarded.

[0033] Optionally, in the above-mentioned method for safely controlling the release of a drag parachute for a medium-to-large aircraft, the power distribution unit adopts a DC solid-state power controller, including: a drag parachute release power distribution channel and a drag parachute release power distribution channel;

[0034] The drag parachute parachute release power distribution channel is electrically connected to the double-redundant parachute release ignition cap seat; the drag parachute parachute jettison power distribution channel is electrically connected to the double-redundant parachute jettison ignition cap seat to achieve connection control of the corresponding ignition cap seat.

[0035] Beneficial effects of the invention: The embodiment of the invention provides a method for safely controlling the release of a drag parachute for a medium-to-large aircraft, which has the following beneficial effects:

[0036] 1) Improved the reliability of drag parachute deployment and parachute throwing;

[0037] The present invention optimizes the design from the following three aspects for the existing aircraft platform, thereby improving the reliability of the drag parachute release and parachute throwing: on the one hand, the parachute release button is installed in a sunken manner, which effectively solves the hidden danger of the button being accidentally touched and connected, while ensuring the accessibility and timeliness of the operation, and ensuring that the drag parachute can be released in the first time in an emergency. A protective cover is used for the parachute throwing button, which can effectively prevent the pilot from accidentally touching it; on the other hand, a double-redundant parachute release and throwing switch control circuit is adopted, and the left and right pilots can realize the control of parachute release and throwing through the left and right drag parachute control panels. A double-redundant parachute release and throwing ignition cap seat is adopted to ensure the throwing of the drag parachute. On the third hand, the parachute release switch signal is cross-linked with the altitude, speed, wheel load signal, and landing gear lowering position signal, and a comprehensive logical judgment is performed to effectively improve the reliability of parachute release.

[0038] 2) A method for automatically dropping the parachute in normal and emergency situations is proposed to improve the maintainability of the drag parachute and the safety of the aircraft

[0039] During the landing and taxiing process of the aircraft, if the parachute is not released in time, it will cause the parachute to be pulled and damaged. In order to improve the maintainability of the drag parachute, an automatic parachute release control method is proposed. Specifically, when the speed is less than or equal to 40km / h, the control unit controls the parachute release power distribution channel in the power distribution unit to be connected, and energizes the ignition cap seat on the line to control the drag parachute to be released in time. During the takeoff and flight process of the aircraft, if the drag parachute accidentally releases, the control unit also controls the distribution unit to energize the parachute release line to control the drag parachute to be released in time, thereby improving the safety of the aircraft.

[0040] 3) Use control unit and solid-state power distribution unit to improve the accuracy of fault location

[0041] The present invention uses a control unit and a power distribution unit to realize the collection and distribution of control signals. The solid-state power controller in the power distribution unit monitors the load and its own state in real time through a built-in logic controller, makes judgments in real time, and reports the monitored information to the upper system and the control unit in real time. The control unit performs systematic management, realizes closed-loop control, and shuts down or prohibits connection in the fault state. At the same time, the solid-state power controller has an online test interface, which is convenient for building complex digital management of power distribution systems, greatly improving the reliability of the drag parachute control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0043] Figure 1 A flow chart of a method for safely controlling the release of a drag parachute for a medium-to-large aircraft provided by an embodiment of the present invention;

[0044] Figure 2 for Figure 1 A schematic diagram of a drag parachute control panel in the illustrated embodiment; Figure 2 Figure a is a top view of the drag parachute control panel, and figure b is a cross-sectional view. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present invention more clear, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other arbitrarily without conflict.

[0046] As explained in the above background technology, the drag parachute is installed at the tail of the aircraft as an auxiliary deceleration device for the aircraft. During the return-to-factory landing process, in order to shorten the landing roll distance, reduce the investment in runway construction, extend the service life of the aircraft wheel brake device, and temporarily terminate the flight mission in the event of an emergency such as a wheel explosion during takeoff and landing, and ensure flight safety, a deceleration device is needed to decelerate. The aircraft deceleration methods mainly include: wheel braking deceleration, drag parachute deceleration, flap control deceleration and reverse thrust deceleration.

[0047] The wheel braking deceleration method realizes the control of short-distance takeoff and landing braking, ground taxiing, front wheel turning, etc.; the wheel braking deceleration method is easily affected by factors such as asymmetric loads on the left and right main wheels, landing gear crawling, airport crosswinds and brake disc wear, so other deceleration methods are needed to achieve smooth deceleration of the aircraft. The flap control deceleration method changes the aerodynamic effect on the wing by increasing the wing area and changing the curvature of the wing; the flap deployment angle will be gradually adjusted according to the speed of the aircraft at this time. Although increasing the flap deployment angle can increase resistance, excessive deployment may cause fatigue damage to the wing structure. In addition, the deployment of the flap will reduce the maneuverability of the aircraft, and usually requires the coordination of other deceleration devices (such as spoilers, wheel braking deceleration, drag parachute deceleration, and reverse thrust deceleration). The reverse thrust deceleration method generates reverse thrust to achieve faster deceleration by directing the gas jet direction of the engine duct outlet toward the front of the engine. Although the reverse thrust device used in this deceleration method is very beneficial for shortening the landing time and distance of the aircraft, it will increase the weight and fuel consumption of the engine and reduce the aircraft's range. In addition, the reverse thrust airflow ejected by the reverse thrust device will pose a potential threat to the normal landing and rolling process of the aircraft, especially causing a certain impact on the performance or aerodynamic stability of the engine.

[0048] Based on the wheel braking deceleration, flap control deceleration, and drag parachute deceleration methods used in existing aircraft platforms, as well as the following problems discovered when applying drag parachute deceleration during field use, the present invention optimizes the design of the drag parachute deceleration solution.

[0049] 1) The umbrella is accidentally released or thrown out due to the switch being touched by mistake

[0050] The drag parachute switch needs to be arranged on the left and right drag parachute control panels, which are located on the left and right sides of the control panel. During operation, the pilot is particularly prone to accidental touch, so anti-accidental touch measures need to be designed.

[0051] 2) The parachute cannot be released or thrown away reliably due to problems with the control circuit or control components

[0052] If a single control circuit fails, the drag parachute cannot be released or jettisoned in time. Therefore, a double-redundant drag parachute jettison switch control circuit is required, so that both the left and right pilots can control the parachute jettisoning. In addition, two parallel ignition cap seats and electric squibs are used in the drag parachute release mechanism and jettisoning mechanism to improve the reliability of the drag parachute jettisoning.

[0053] 3) Failure to release the parachute in time, resulting in the parachute being pulled and damaged, affecting the safety of the aircraft

[0054] During takeoff or flight, if the drag parachute is accidentally released, you need to throw it away in time to ensure the safety of the aircraft. During the landing and taxiing deceleration process, after the drag parachute is released, if the aircraft speed is less than or equal to 40km / h, you need to throw the drag parachute away in time to avoid the parachute being pulled and damaged.

[0055] 4) The control signals for parachute release and parachute throwing are short-duration pulse signals, which are difficult to collect by the flight parameter collector. After a fault occurs, it is difficult to accurately locate the fault.

[0056] In view of the above-mentioned problems existing in the drag parachute deceleration method, the embodiment of the present invention proposes a method for safely controlling the release of a drag parachute for medium and large aircraft, taking into account the need to ensure the reliability of the aircraft drag parachute control, so that the drag parachute can be used normally in an emergency, extend the service life of the aircraft wheel brake device, effectively shorten the aircraft landing runway, and prevent the abnormal release of the drag parachute during normal takeoff and flight of the aircraft, disrupting the aircraft's flight attitude and affecting flight safety. It is necessary to improve the reliability of the normal opening of the drag parachute during the aircraft's takeoff and flight, and formulate countermeasures for the accidental opening of the drag parachute to ensure aircraft safety.

[0057] The present invention provides the following specific embodiments which can be combined with each other. The same or similar concepts or processes may not be described in detail in some embodiments.

[0058] The drag parachute is installed in the drag parachute box at the lower part of the fuselage. The drag parachute is released by opening the drag parachute box door through the drag parachute release mechanism and releasing the drag parachute under the action of gravity. The drag parachute opens, generates air resistance, and reduces the aircraft's taxiing speed. After the aircraft speed drops to 30-40 km / h, the drag parachute ring is removed from the hook through the drag parachute throwing mechanism and the drag parachute is thrown away. A method for safely controlling the release of a drag parachute for a medium-to-large aircraft provided in an embodiment of the present invention, a drag parachute control system for executing the release safety control method includes: a control unit, a drag parachute control panel connected to the control unit, a power distribution unit, a drag parachute release micro switch, and a pyrotechnic cap seat connected to the power distribution unit, and the drag parachute control panel is used to send a release signal.

[0059] like Figure 1 As shown, it is a flow chart of a method for safely controlling the release of a drag parachute for a medium-to-large aircraft provided by an embodiment of the present invention. The method for safely controlling the release of a drag parachute for a medium-to-large aircraft provided by an embodiment of the present invention comprises the following steps:

[0060] Step 1, receiving, through a control unit, a parachute release signal sent by a parachute control panel, and a corresponding signal sent by an external device or component interconnected with the parachute control system;

[0061] Step 2: The control unit determines whether the parachute release condition is met based on the internal control logic according to the received signals. When it is determined that the parachute release condition is met, the control unit controls the power distribution unit to connect the parachute release electric squib in the ignition cap seat to open the drag parachute door and implement the parachute release operation.

[0062] Step 3: After the drag parachute door is opened, the drag parachute release micro switch is pressed and turned on, and the drag parachute release micro switch generates a parachute release signal;

[0063] Step 4, the control unit receives the parachute jettisoning signal from the drag parachute control panel and the ground speed signal from the inertial navigation device, and determines whether the normal parachute jettisoning conditions are met based on its internal logic. When it is determined that the normal parachute jettisoning conditions are met, the control unit controls the power distribution unit to connect the electric squib in the ignition cap seat, controls the drag parachute hook to open, and removes the drag parachute from the hook to complete the parachute jettisoning operation.

[0064] It should be noted that the external devices or components interconnected by the drag parachute control system in the embodiment of the present invention include:

[0065] Inertial navigation equipment, used to provide ground speed signals;

[0066] The left and right main landing gear lowering micro switches are used to send out the left and right main landing gear lowering signals respectively;

[0067] A radio altimeter, used to send out altitude signals;

[0068] Main landing gear ground switch, used to send main landing gear wheel load signal.

[0069] The following is a description of the functions of the components of the drag parachute control system in the embodiment of the present invention to illustrate the specific implementation of the embodiment of the present invention:

[0070] (1) Parachute control panel

[0071] The drag parachute control panel is equipped with a "parachute release" switch and a "parachute jettison" switch, and measures are taken to prevent accidental contact of the switches. A dual-redundancy drag parachute release switch control circuit and a drag parachute jettison switch control circuit are adopted, which are arranged on the left and right drag parachute control panels respectively. Both the left and right pilots can independently control the jettisoning of the drag parachute, effectively ensuring the reliable jettisoning of the drag parachute.

[0072] In each drag parachute control panel, the "parachute release" switch uses a protective cover, which can effectively prevent the pilot from accidentally touching the parachute release switch. The method of adding a protective cover is not suitable for the "parachute release" switch. The use of a drag parachute is an emergency procedure when the aircraft is at a high speed, and it is required to release the drag parachute as soon as possible in this emergency. According to calculations, after the protective cover is installed, the protective cover must be opened before the button can be pressed, which will cause the pilot to delay the operation by about 1 second. Under normal circumstances, the landing run speed of the aircraft is 230km / h, and the aircraft run distance in 1 second is about 70m. In an emergency, the speed is faster. At this time, the drag parachute is particularly critical for the braking and deceleration of the aircraft; considering that the pilot is in a highly nervous state during the emergency parachute release and braking and deceleration, it may lead to a prolonged time to open the protective cover or even a situation where it cannot be opened due to over-tight installation. The form of opening the protective cover on the switch increases the safety risk of the aircraft running out of control or running off the runway, which affects the safety of the aircraft. Based on the above analysis, in order to ensure that the parachute is released as soon as possible, the "parachute release" switch is not allowed to use a protective cover. The "parachute release" switch adopts a naturally sunken installation form. See the bottom plate of the drag parachute for a diagram Figure 2 Specifically, a groove is formed on the bottom plate of the control panel at the "parachute" switch position, and the "parachute" switch is embedded in the groove to ensure that the horizontal plane of the "parachute" switch is lower than the bottom plate. This solution effectively solves the hidden danger of the "parachute" switch being accidentally connected, and ensures the accessibility and timeliness of the operation, ensuring that the drag parachute can be released as soon as possible in an emergency.

[0073] The top of the "parachute release" switch is integrated with a parachute release signal light. The "parachute release" switch has the functions of parachute release control and parachute release signal light indication. Specifically, the parachute release signal light is linked with the drag parachute release micro switch. When the drag parachute box door is opened, the drag parachute release micro switch will be pressed, and the drag parachute will be released at the same time. The drag parachute release micro switch is closed, and the parachute release signal light circuit on the "parachute release" switch is connected, and the signal light is on, indicating that the drag parachute has been released. The "parachute throwing" switch has the function of manual parachute throwing control.

[0074] (2) Control unit

[0075] The control unit receives the flight altitude, speed, wheel-loaded signals, left and right landing gear lowering signals, drag parachute lowering micro switch signals, and left and right drag parachute control board "release" switch signals and "throw" switch signals from the external cross-linking equipment, and performs logical judgment; controls the power distribution unit to distribute power to the corresponding power supply path to ensure that the drag parachute will not be accidentally released in the air. When the following five conditions are met: ① the "release" switch on the left or right drag parachute control board is turned on; ② the ground speed is ≤230km / h; ③ the left main landing gear or right main landing gear lowering micro switch is turned on; ④ the low-altitude radio altimeter shows a height of less than 3m; ⑤ the main landing gear has a wheel-loaded signal "hanging in the air", the control unit controls the "parachute release" power distribution channel of the power distribution unit to distribute power to the drag parachute release ignition cap seat, and the electric squib in the ignition cap seat is energized and exploded, driving the relevant mechanism to open the drag parachute box door and release the drag parachute under the action of weight.

[0076] When any of the above five judgment conditions is not met and the drag parachute releasing microswitch is turned on, the control unit controls the "parachute throwing" power distribution channel of the power distribution unit to distribute power to the drag parachute throwing ignition cap seat, and the electric detonator in the ignition cap seat is energized and exploded, driving the relevant mechanism to throw away the drag parachute.

[0077] In addition, the parachute is dropped by associating the parachute dropping signal and the parachute releasing signal emitted by the drag parachute control panel with the speed. When the parachute dropping microswitch is turned on and the "parachute dropping" switch on the left or right drag parachute control panel is received, or the ground speed is ≤40km / h, the control unit controls the "parachute dropping" power distribution channel of the power distribution unit to drop the drag parachute.

[0078] The ignition cap seat is installed on the drag parachute box and is associated with the hatch opening drive mechanism of the drag parachute box. The hatch door is driven to open by the impulse generated by the instantaneous explosion of the electric squib in the ignition cap seat when it is energized. The ignition cap seat is configured as a double-redundant parachute release ignition cap seat and a double-redundant parachute throwing ignition cap seat, and the electric squib is connected inside the ignition cap seat. Specifically, when any parachute release ignition cap seat is energized, the electric squib inside it is energized and exploded, which can drive the relevant mechanism to open the hatch door of the drag parachute box and release the drag parachute under the action of weight. When any parachute throwing ignition cap seat is energized, the electric squib inside it is energized and exploded, which can drive the relevant mechanism to throw away the drag parachute. Improve the reliability of the drag parachute throwing.

[0079] (3) Power distribution unit

[0080] The power distribution unit adopts a DC solid-state power controller, including: a parachute release distribution channel and a parachute drop distribution channel. The DC solid-state power controller is an important component of the modern aircraft automatic power distribution system and is a switching device composed of semiconductor devices. It has the characteristics of no mechanical contacts, fast response speed, long service life, high reliability, no arc, and strong electromagnetic interference ability. Specifically, the voltage controllable characteristics of semiconductor devices are used to achieve fast switching of the load on and off. At the same time, the voltage physical isolation between control and output is met to prevent voltage breakdown and current backflow to other devices; the solid-state power controller integrates the protection function of the circuit breaker, and implements protection action when the load abnormally exceeds the set value. Avoid overcurrent and short circuit from causing damage to the equipment and the solid-state power controller itself; the solid-state power controller integrates the voltage status monitoring function of the load, and implements protection action when the load abnormally exceeds the set value. Avoid undervoltage, overvoltage, and overvoltage from causing damage to the equipment and the solid-state power controller itself; the solid-state power controller monitors the load and its own status in real time through the built-in logic controller, makes judgments in real time, and shuts down or prohibits connection in the fault state; the solid-state power controller monitors the load and its own status in real time, makes judgments in real time, and reports the monitored information to the upper system and control unit in real time, which is systematically managed by the control unit to achieve closed-loop control. At the same time, the solid-state power controller has an online test interface, which is convenient for building complex digital management of power distribution systems and greatly improves the reliability of power distribution systems.

[0081] The main landing gear wheel load signal is sent by the main landing gear air-to-ground switch. When the aircraft is in the air, the wheel load signal is a ground signal; when the aircraft is on the ground, the wheel load signal is a suspended signal.

[0082] The left and right main landing gear lowering signals are sent by the left and right main landing gear lowering micro switches. When the left or right main landing gear is lowered, the micro switch on the shock absorber strut will be pressed to send the landing gear lowering signal.

[0083] The altitude signal is sent by the radio altimeter, which is measured by the low-altitude radio altimeter and sends the altitude information to the control unit. The low-altitude radio altimeter is a radio altimeter with a frequency-modulated continuous wave constant beat system, which can accurately measure the true altitude of the aircraft from the ground and water.

[0084] The ground speed signal is sent by the inertial navigation device, which is calculated by the inertial navigation component based on the acceleration in the X direction, the Y direction and the Z direction of the aircraft, and sends the speed information to the control unit.

[0085] The drag parachute control system provided by the embodiment of the present invention has the following three working modes when executing the drag parachute release safety control method, including the drag parachute manual release, drag parachute normal release, and drag parachute emergency release working modes.

[0086] Mode 1, manual deployment of the drag parachute.

[0087] Connect the "Drag Parachute" circuit breaker on the circuit breaker board. When the following five conditions are met: ① Press the "Drag Parachute" button switch on the left drag parachute control panel or the right drag parachute control panel, and the "Drag Parachute" button switch is turned on; ② Receive the wheel load signal provided by the landing gear indicating that the aircraft is on the ground; ③ The left main landing gear or the right main landing gear is in place; ④ The low-altitude radio altimeter shows that the altitude is less than 3m; ⑤ The inertial navigation unit shows that the ground speed is ≤230km / h. Then, the power distribution unit for controlling the parachute can be connected, and power can be supplied to the parachute release ignition cap seat, so that the electric squib in the ignition cap seat is connected and exploded, the drag parachute box door is opened, the drag parachute is released, and the manual drag parachute release function is realized. After the drag parachute is released, the parachute release micro switch on the drag parachute box is actuated, and the power supply line of the drag parachute release indicator light is connected. The "Parachute Release" indicator light on the drag parachute control panel lights up, indicating that the drag parachute has been released.

[0088] Mode 2, the drag parachute is dropped normally.

[0089] Press the "parachute jettison" switch on the drag parachute control panel, or the ground speed is ≤40km / h. If the parachute release microswitch on the drag parachute box is turned on, the control unit can control the power distribution unit that operates the parachute jettison, supply power to the parachute jettison ignition cap seat, so that the electric detonator in the ignition cap seat is connected and exploded, realizing the normal jettisoning of the drag parachute.

[0090] Mode 3, emergency parachute jettisoning of drag parachute.

[0091] If any one of the five judgment conditions in mode 1 is not met and the drag parachute microswitch is abnormally connected, that is, the drag parachute is abnormally released, the drag parachute jettison power distribution unit will automatically power on to supply power to the parachute jettison ignition cap seat, causing the electric detonator in the ignition cap seat to be connected and exploded, thereby achieving emergency jettisoning of the drag parachute.

[0092] Although the embodiments disclosed in the present invention are as above, the contents are only embodiments adopted to facilitate understanding of the present invention and are not intended to limit the present invention. Any technician in the field to which the present invention belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A method for safely controlling the release of a drag parachute for a medium or large aircraft, characterized in that: The drag parachute control system for executing the release safety control method comprises: a control unit, a drag parachute control panel connected to the control unit, a power distribution unit, a drag parachute release micro switch, and a pyrotechnic cap seat connected to the power distribution unit, wherein the drag parachute control panel is used to send a release signal; the method comprises: Step 1, receiving, through a control unit, a parachute release signal sent by a parachute control panel, and a corresponding signal sent by an external device or component interconnected with the parachute control system; Step 2: The control unit determines whether the parachute release condition is met based on the internal control logic according to the received signals. When it is determined that the parachute release condition is met, the control unit controls the power distribution unit to connect the parachute release electric squib in the ignition cap seat to open the drag parachute door and implement the parachute release operation. Step 3: After the drag parachute door is opened, the drag parachute release micro switch is pressed and turned on, and the drag parachute release micro switch generates a parachute release signal; Step 4, the control unit receives the parachute jettison signal from the drag parachute control panel and the ground speed signal from the inertial navigation device, and determines whether the normal parachute jettison conditions are met based on its internal logic. When it is determined that the normal parachute jettison conditions are met, the control unit controls the power distribution unit to connect the parachute jettison electric squib in the ignition cap seat, controls the drag parachute hook to open, and allows the drag parachute to fall off the hook, completing the parachute jettison operation.

2. The method for safely controlling the release of a drag parachute for a medium-to-large aircraft according to claim 1, characterized in that: The external devices or components interconnected by the drag parachute control system include: Inertial navigation equipment, used to provide ground speed signals; The left and right main landing gear lowering micro switches are used to send out the left and right main landing gear lowering signals respectively; A radio altimeter, used to send out altitude signals; Main landing gear ground switch, used to send main landing gear wheel load signal.

3. The method for safely controlling the release of a drag parachute for a medium-to-large aircraft according to claim 2, characterized in that: The judgment logic for determining whether the umbrella release condition is met is that the following conditions are met at the same time: ① The "release" switch on the left or right drag parachute control panel is turned on; ② Ground speed ≤ 230 km / h; ③The left main landing gear or right main landing gear lowering micro switch is turned on; ④ The low-altitude radio altimeter shows an altitude of less than 3m; ⑤The main landing gear has a wheel load signal of "hanging".

4. The method for safely controlling the release of a drag parachute for a medium-to-large aircraft according to claim 3, characterized in that: After step 3, the method further includes: When the drag parachute release micro switch is turned on, the control unit determines whether the emergency parachute release condition is met based on the internal control logic by receiving various signals. When it is determined that the emergency parachute release condition is met, the control unit controls the power distribution unit to connect the parachute release electric squib in the ignition cap seat, controls the drag parachute hook to open, and removes the drag parachute from the hook, thereby completing the parachute release operation. The judgment logic of the emergency parachute throwing condition is: when it is judged that any one of the five conditions in the parachute throwing condition is not met, it is judged that the emergency parachute throwing condition is met.

5. The method for safely controlling the release of a drag parachute for a medium-to-large aircraft according to claim 2, characterized in that: The judgment logic for meeting the parachute casting condition is to meet at least one condition: Receiving a "parachute jettison" switch-on signal from the left parachute control panel or the right parachute control panel; or, Ground speed ≤40km / h.

6. The method for safely controlling the release of a drag parachute for a medium-to-large aircraft according to any one of claims 1 to 5, characterized in that: The drag parachute control panel includes left and right drag parachute control panels respectively arranged for the left and right pilots to independently control the release and throwing of the drag parachute; Each drag parachute control panel is provided with a "parachute release" switch and a "parachute throwing" switch; wherein, the "parachute throwing" switch is provided with a protective cover to prevent the pilot from accidentally touching the "parachute throwing" switch; the "parachute release" switch is arranged in a naturally sunken installation form, and a groove is formed on the bottom plate of the drag parachute control panel at the position of the "parachute release" switch, and the "parachute release" switch is embedded in the groove, so that the horizontal plane of the "parachute release" switch is lower than the bottom plate; A parachute releasing signal light is integrated on the top of the "parachute releasing" switch, so that the "parachute releasing" switch has the functions of parachute releasing control and parachute releasing signal light indication; and the parachute releasing signal light is cross-linked with the drag parachute releasing micro switch, which is used to light up the parachute releasing signal light on the "parachute releasing" switch after the drag parachute box door is opened and the drag parachute releasing micro switch is pressed, so as to indicate that the drag parachute has been released.

7. The method for safely controlling the release of a drag parachute for a medium-to-large aircraft according to any one of claims 1 to 5, characterized in that: The detonator seat is installed on the drag parachute box and is associated with the hatch opening drive mechanism of the drag parachute box. The detonator seat drives the hatch opening drive machine to open or controls the drag parachute hook to open through the impulse generated by the instantaneous explosion of the electric squib in the detonator seat when it is energized. The ignition cap seat is configured as a double-redundant parachute ignition cap seat and a double-redundant parachute ignition cap seat, and an electric squib is arranged in the passage of each ignition cap seat; When one of the parachute release ignition caps is energized, the electric squib inside it is energized and explodes, thereby opening the drag parachute box door and releasing the drag parachute under the action of weight; When one of the parachute ignition cap seats is energized, the electric squib inside it is energized and explodes, controlling the drag parachute hook to open, allowing the drag parachute to fall off the hook and be discarded.

8. The method for safely controlling the release of a drag parachute for a medium-to-large aircraft according to claim 7, characterized in that: The power distribution unit adopts a DC solid-state power controller, including: a drag parachute release power distribution channel and a drag parachute throwing power distribution channel; The drag parachute parachute release power distribution channel is electrically connected to the double-redundant parachute release ignition cap seat; the drag parachute parachute jettison power distribution channel is electrically connected to the double-redundant parachute jettison ignition cap seat to achieve connection control of the corresponding ignition cap seat.

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