Digital cabin pressure regulation method and system for large aircraft

Abstract

The application discloses a digital cabin pressure regulating method and system for large aircraft. The on-board system and cabin pressure signals are collected to calculate a target pressure; the target pressure is used to calculate a target flow; the target flow is used to calculate exhaust flow of exhaust valve I and exhaust valve II according to a preset exhaust flow distribution ratio; and the exhaust flow of the exhaust valve I and the exhaust valve II is used to calculate opening angle of the exhaust valve I and the exhaust valve II to control the air flow rate out of the cabin. The application can achieve the purposes of controlling the cabin height, the cabin height change rate and the air exhaust flow distribution in the cabin.

Description

Technical Field

[0001] This invention belongs to the field of aircraft cabin pressure regulation technology, specifically relating to a digital cabin pressure regulation method and system for large aircraft. Background Technology

[0002] Currently, when the aircraft's air supply flow changes during flight, the airflow in the aircraft cabin is prone to become uncontrollable. The air in the cabin cannot be discharged from specific locations in a timely manner, resulting in abnormal airflow circulation inside and outside the cabin, which reduces the comfort of passengers. Summary of the Invention

[0003] The purpose of this invention is to provide a digital cockpit pressure regulation method and system for large aircraft. This invention can achieve the objectives of controlling cockpit altitude, cockpit altitude change rate, and cockpit air exhaust flow distribution.

[0004] The technical solution of this invention is: a digital cabin pressure regulation method for large aircraft, which involves collecting onboard system and cabin pressure signals to calculate target pressure; calculating target flow rate based on target pressure; calculating exhaust flow rate of exhaust valve I and exhaust valve II based on target flow rate and a preset exhaust flow rate distribution ratio; and calculating the opening angle of exhaust valves I and II based on the exhaust flow rate of exhaust valves I and II to control the proportion of air flow rate exiting the cabin.

[0005] In the aforementioned digital cabin pressure regulation method for large aircraft, the target pressure is calculated by using the onboard system and cabin pressure signals to determine the following parameters:

[0006] a) Maximum pressure difference between the cabin and the outside atmosphere;

[0007] b) The difference between the target cabin pressure and the actual cabin pressure;

[0008] c) Cabin pressure change rate limit range;

[0009] d) Cabin pressure regime at each stage of the aircraft;

[0010] Select the appropriate parameters as the target pressure according to the priority order a) > b) > c) > d).

[0011] In the aforementioned digital cockpit pressure regulation method for large aircraft, the target flow rate is calculated using the following formula:

[0012]

[0013] In the formula: △Pc(t) is the difference between the target cabin pressure and the actual cabin pressure in the current control loop;

[0014] △Pc(t-1) is the difference between the target cabin pressure and the actual cabin pressure in the previous control loop;

[0015] W(t) represents the target flow rate in the current control loop;

[0016] W(t-1) is the target flow rate in the previous control loop;

[0017] d is the control gain, T is the sampling time, and T a is the time constant.

[0018] In the aforementioned digital cockpit pressure regulation method for large aircraft, the opening angles of exhaust valves I and II are calculated as follows:

[0019] The effective flow area of ​​the exhaust valve can be calculated using the following formula:

[0020] F = W * ε / (P) c *μ)

[0021] In the formula:

[0022] F represents the effective flow area of ​​the valve;

[0023] W represents the target traffic volume;

[0024] ε represents the exhaust flow distribution ratio;

[0025] P c Current cabin pressure;

[0026] μ is a coefficient;

[0027] Based on the effective flow area of ​​the exhaust valve, the relationship between the actual angle of the exhaust valve and the effective flow area of ​​the exhaust valve is obtained through CFD simulation calculation, and then the opening angle of the exhaust valve is calculated.

[0028] A digital cockpit pressure regulation system for a large aircraft, as described above, includes:

[0029] The cabin pressure controller is used to calculate the opening angles of exhaust valves I and II based on the onboard system and cabin pressure signals.

[0030] Exhaust valve I is used to control the airflow out of the cabin;

[0031] Exhaust valve II is used to control the airflow out of the cabin;

[0032] Pressure sensors are used to collect cabin pressure signals.

[0033] In the aforementioned digital cabin pressure regulation system, the cabin pressure controller includes two independent automatic control channels for independently calculating the opening angles of exhaust valves I and II as redundant backups.

[0034] The aforementioned digital cabin pressure regulation system also includes a cabin pressure control panel, which integrates an "automatic / manual" switching module and a manual control module. The "automatic / manual" switching module is used to switch between the automatic control channel and the manual control channel. The manual control module is used to manually control the opening angle of exhaust valves I and II when switching to the manual control channel.

[0035] In the aforementioned digital cabin pressure regulation system, a safety valve is provided on the automatic control channel to implement the positive / negative pressure difference limiting function of the cabin.

[0036] The advantages of this invention are: This invention collects onboard system and cabin pressure signals through the automatic control channel A or B of the cabin pressure controller. According to a pre-set pressure regime, the pressure control is logically calculated into exhaust valve angle control. Simultaneously, the exhaust flow rates of exhaust valves I and II are calculated according to a predetermined exhaust flow distribution ratio. Information is exchanged with the exhaust valves via RS422 communication, thereby controlling the opening angles of exhaust valves I and II. By changing the opening angles of exhaust valves I and II, the proportion of airflow out of the cabin is controlled, thus achieving the purpose of controlling cabin height, cabin height change rate, and cabin air exhaust flow distribution. This invention's system has triple-redundant control functionality, including two automatic control channels and one manual control channel, making it safer and more reliable.

[0037] This invention uses a digital cabin pressure regulation system to distribute cabin air exhaust flow, achieving precise adjustment of cabin airflow based on occupant comfort, effectively improving the riding experience and comfort.

[0038] The main function of the digital cockpit pressure regulation system of this invention is to automatically control the cabin pressure of the aircraft pressurized section, which includes the cockpit, cabin, and cargo / installation area, during flight and ground operations, so as to achieve a safe and comfortable level.

[0039] It also enables the proportional distribution of airflow between the front and rear exhaust valves, improving the economy and versatility of the exhaust valves, ensuring the safety of the crew during high-altitude flight, enhancing the comfort of the crew during high-altitude flight, and preventing the crew from experiencing decompression sickness.

[0040] The primary function of this digital cabin pressure regulation system is to automatically control the cabin pressure in the pressurized sections of the aircraft, including the cockpit, passenger compartment, and cargo / installation areas, during flight and ground operations, to maintain a safe and comfortable level.

[0041] It also enables the proportional distribution of airflow between the front and rear exhaust valves, ensuring the safety of the crew during high-altitude flight, improving the crew's comfort during high-altitude flight, and preventing crew members from experiencing high-altitude decompression sickness. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of a digital cockpit pressure regulation system. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0044] Example 1. Composition of the digital cockpit pressure regulation system, see [link / reference]. Figure 1 It includes: cabin pressure control panel, cabin pressure controller, pressure sensor I, pressure sensor II, exhaust valve I, exhaust valve II, safety valve I, and safety valve II.

[0045] Step 1: Pressure sensors I / II collect cabin pressure signals, and then, in conjunction with signals from the onboard systems, calculate the target cabin pressure in automatic control channels A / B according to the following priority order:

[0046] a) Maximum pressure difference between the cabin and the outside atmosphere;

[0047] b) The difference between the target cabin pressure and the actual cabin pressure;

[0048] c) Cabin pressure change rate limit range;

[0049] d) Cabin pressure regime for each stage of the aircraft.

[0050] Step 2: Based on the target pressure calculated in Step 1, calculate the target flow rate using the following formula:

[0051]

[0052] In the formula:

[0053] △Pc(t) is the difference between the target pressure and the actual cabin pressure in the current loop;

[0054] △Pc(t-1) is the difference between the target pressure and the actual cabin pressure in the previous control loop.

[0055] W(t) represents the target flow rate;

[0056] W(t-1) represents the target flow rate in the control loop of the previous step;

[0057] d is the control gain, T is the sampling time, and T a is the time constant.

[0058] Step 3: Based on the target flow rate calculated in Step 2, allocate the flow rate to exhaust valve I and exhaust valve II according to the exhaust flow rate ratios ε5 and ε6 (ε5 + ε6 = 1) required by the system design. This yields the required exhaust flow rate W*ε5 for exhaust valve I and the required exhaust flow rate W*ε6 for exhaust valve II.

[0059] Step 4: Based on the exhaust flow rates W*ε5 and W*ε6 calculated in Step 3, the effective flow area of ​​the exhaust valve can be calculated using the following formula.

[0060] F = W / (P) c *μ)

[0061] In the formula:

[0062] F represents the effective flow area of ​​the valve;

[0063] W represents the target traffic volume;

[0064] P c Current cabin pressure;

[0065] μ is a coefficient.

[0066] Step 5: Based on the effective flow area of ​​the exhaust valve calculated in Step 4, the relationship between the actual angle of the exhaust valve and the effective flow area of ​​the exhaust valve can be obtained through CFD simulation calculation. Thus, the characteristic curve between the exhaust valve angle and the effective flow area can be obtained, and the curve can be embedded into the cabin pressure control system to calculate the target angle of the exhaust valve.

[0067] Step 6: The cabin pressure regulation system calculates the target angle of the exhaust valve and then controls the exhaust valve to operate according to the target angle. By changing the opening angle of exhaust valve I and exhaust valve II, the proportion of airflow out of the cabin is controlled, thereby achieving the purpose of controlling cabin height, cabin height change rate and cabin air exhaust flow distribution.

[0068] The cabin pressure regulation system has triple redundancy control, including two automatic control channels and one manual control channel.

[0069] The automatic control system includes two identical but independent control channels. Either automatic control channel can control the cabin pressure, the rate of pressure change, and the distribution of air exhaust flow within the cabin.

[0070] The cabin pressure control panel is equipped with an "emergency depressurization" button, which can control the automatic channel to achieve emergency depressurization.

[0071] The manual control channel is a purely hardware-based circuit, serving as a backup in case both automatic control channels fail, and is completely independent of the two automatic control channels. The unit switches between automatic and manual control modes via the "automatic / manual" switching module on the cabin pressure control panel. Then, it controls the opening angles of exhaust valve I and exhaust valve II through the cabin pressure control panel, thereby controlling the proportion of airflow out of the cabin and achieving the purpose of controlling cabin height, cabin height change rate, and cabin air exhaust flow distribution.

[0072] The digital cabin pressure regulation system uses pneumatic safety valves I and II to limit the positive / negative pressure difference in the cabin, thereby ensuring the safety of the aircraft structure and occupants.

[0073] Taking the automatic control scheme for takeoff and landing scenarios at a plain airport as an example, the specific details are as follows:

[0074] Automatic control is the operational state in which the cabin altitude is adjusted according to the aircraft's flight altitude and a predetermined pressure regime during normal aircraft operation.

[0075] During takeoff and landing at a plain airport, after the system is powered on and the digital cabin pressure regulation system completes its self-test, it enters a periodic inspection. At this time, the system automatically controls exhaust valve I and exhaust valve II to rotate a certain angle in the closing direction to achieve the ground pre-pressurization function (cabin pre-pressurization value is 1 kPa).

[0076] Climbing phase: After the aircraft takes off, the digital cockpit pressure regulation system controls the cockpit to gradually approach 2400m according to the predetermined pressure regime, while meeting the pressure change rate, until the cockpit altitude reaches 2400m.

[0077] Cruise Phase: Once the aircraft enters the cruise phase, the cabin pressure is kept stable according to the cabin altitude value corresponding to the aircraft's flight altitude in the predetermined pressure regime.

[0078] Descent phase: Once the aircraft begins its descent, the digital cabin pressure regulation system controls the cabin pressure according to the predetermined pressure regime that corresponds to the flight altitude and cabin altitude, until the aircraft lands and then returns to standby mode.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be covered within the protection scope of the present invention.

Claims

1. A digital cockpit pressure regulation method for large aircraft, characterized in that, The target pressure is calculated by acquiring pressure signals from the onboard system and cabin; the target flow rate is then calculated based on the target pressure. The exhaust flow rates of exhaust valve I and exhaust valve II are calculated based on the target flow rate and the preset exhaust flow rate distribution ratio. Based on the exhaust flow rate of exhaust valves I and II, the opening angle of exhaust valves I and II is used to control the proportion of airflow out of the cabin; The target pressure is calculated using the following parameters derived from the onboard systems and cabin pressure signals: a) Maximum pressure difference between the cabin and the outside atmosphere; b) The difference between the target cabin pressure and the actual cabin pressure; c) Cabin pressure change rate limit range; d) Cabin pressure regime at each stage of the aircraft; Select the appropriate parameters as the target pressure according to the priority order a) > b) > c) > d); The target traffic is calculated using the following formula: ； In the formula: △Pc(t) is the difference between the target cabin pressure and the actual cabin pressure in the current control loop; △Pc(t-1) is the difference between the target cabin pressure and the actual cabin pressure in the previous control loop; W ( t () represents the target flow rate in the current control loop; W ( t-1 () represents the target flow rate in the previous control loop; d To control the gain, T is the sampling time. a is the time constant.

2. The digital cockpit pressure regulation method for large aircraft according to claim 1, characterized in that, The opening angles of exhaust valves I and II are calculated as follows: The effective flow area of ​​the exhaust valve is calculated using the following formula: F=W*ε / (P c *m) In the formula: F represents the effective flow area of ​​the valve; W represents the target traffic volume; ε represents the exhaust flow distribution ratio; P c Current cabin pressure; μ is a coefficient; Based on the effective flow area of ​​the exhaust valve, the relationship between the actual angle of the exhaust valve and the effective flow area of ​​the exhaust valve is obtained through CFD simulation calculation, and then the opening angle of the exhaust valve is calculated.

3. A digital cockpit pressure regulation system for a large aircraft using the digital cockpit pressure regulation method as described in any one of claims 1-2, characterized in that, include: The cabin pressure controller is used to calculate the opening angles of exhaust valves I and II based on the onboard system and cabin pressure signals. Exhaust valve I is used to control the airflow out of the cabin; Exhaust valve II is used to control the airflow out of the cabin; Pressure sensors are used to collect cabin pressure signals.

4. The digital cockpit pressure regulation system according to claim 3, characterized in that, The cabin pressure controller includes two independent automatic control channels for independently calculating the opening angles of exhaust valves I and II as redundant backups.

5. The digital cabin pressure regulation system according to claim 4, characterized in that, It also includes a cabin pressure control panel, which integrates an "automatic / manual" switching module and a manual control module; the "automatic / manual" switching module is used to switch between automatic control channels and manual control channels; the manual control module is used to manually control the opening angle of exhaust valves I and II when switching to the manual control channel.

6. The digital cockpit pressure regulation system according to claim 4, characterized in that, The automatic control channel is equipped with safety valves to limit the positive / negative pressure difference in the cabin.

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