Method and system for controlling off of yaw damper

Abstract

The invention discloses a method and a system for controlling yaw damper disconnection. In one embodiment of the invention, a turn-off pre-position signal is generated when the rudder, the yaw damper data transmission path, and / or the primary flight control system operate abnormally, and in response to the turn-off pre-position signal, the yaw damper is turned off if it is determined that at least one of the rudder control link or the yaw function of the rudder is abnormal.

Description

Technical Field

[0001] This invention belongs to the field of aircraft, and in particular relates to a method and system for controlling the disconnection of a yaw damper. Background Technology

[0002] A yaw damper (YD) is an airborne system on an aircraft, primarily used to suppress unstable oscillations along the aircraft's yaw axis. The yaw damper provides Dutch roll damping and turn coordination, maintaining aircraft stability by controlling the rudder.

[0003] The yaw damper typically disconnects in the event of a malfunction, power problem, exceeding its operating range, or pilot intervention. For example, the yaw damper may automatically disconnect if the gyroscope / rate sensor used to detect yaw speed malfunctions, the flight control computer fails, or the rudder control channel fails. With the yaw damper engaged, for aircraft equipped with a YD switch, the pilot can disconnect the yaw damper by pressing the switch; for aircraft without a YD switch, disconnection is sometimes achieved by disconnecting the stability augmentation computer, which may cause other functions that need to continue operating to also disconnect. Regardless of the method, malfunctioning yaw dampers can cause oscillations exceeding the aircraft's structural load limits, leading to catastrophic consequences.

[0004] The status of the control surfaces and the main flight control system (i.e., the main flight control system) can affect the connection / disconnection of YD. However, it cannot be ruled out that disturbing signals can affect the connection / disconnection status of YD, causing unnecessary disconnection of YD, thereby increasing the workload of the crew.

[0005] Therefore, there is a need in the art for an improved method for controlling the disconnection of the yaw damper. Summary of the Invention

[0006] This invention provides a method for controlling the disconnection of a yaw damper. A disconnection pre-positioning signal is generated when the rudder, yaw damper data transmission path, and / or the main flight control system malfunctions. In response to the disconnection pre-positioning signal, if it is determined that at least one of the rudder control link or the rudder's yaw function is malfunctioning, the yaw damper is disconnected. This invention uses a rudder status signal to determine whether to disconnect the yaw damper, which can reduce unnecessary disconnections caused by interference in the ERA signal. When any of the aircraft's elevator, ailerons, or horizontal stabilizer fails, the yaw damper will not disconnect, thereby preventing accidental in-flight disconnection and improving the aircraft's handling stability.

[0007] In one embodiment of the present invention, a method for controlling the yaw damper to disconnect is provided, comprising: when the yaw damper of an aircraft is engaged, determining whether the aircraft's rudder and the yaw damper data transmission path from the yaw damper to the flight control computer are normal; if at least one of the aircraft's rudder and the yaw damper data transmission path is not normal, generating a disconnect pre-position signal; in response to the disconnect pre-position signal, determining whether the rudder control link from the flight control computer to the rudder and the yaw function of the rudder are normal; and if at least one of the rudder control link and the yaw function of the rudder is not normal, generating a yaw damper disconnect signal to disconnect the aircraft's yaw damper.

[0008] In one aspect, the method further includes: determining whether the main flight control system of the aircraft is normal when the yaw damper of the aircraft is engaged; and generating the disconnect pre-position signal when the main flight control system is not operating normally.

[0009] In one respect, at least one of the aircraft's rudder, the yaw damper data transmission path, and the main flight control system malfunctions, including at least one of the following: the rudder fails; the yaw damper data transmission path fails; or the main flight control system enters direct mode.

[0010] In one aspect, the method further includes: in response to the disconnect pre-position signal, further determining whether the transmission link inside the main flight control system, the general input / output of the main flight control system, and the input / output of the automatic flight system are normal; and if at least one of the transmission link inside the main flight control system, the general input / output of the main flight control system, and the input / output of the automatic flight system is abnormal, generating the yaw damper disconnect signal.

[0011] In one aspect, the method further includes: if the rudder control link, the yaw function of the rudder, the transmission link inside the main flight control system, the general input and output of the main flight control system, and the input and output of the automatic flight system are all normal, then a yaw damper activation signal is generated to maintain the yaw damper of the aircraft in operation.

[0012] In one aspect, the method further includes: sending a yaw damper disconnect request in response to the disconnect pre-position signal; and disconnecting the aircraft's yaw damper after the predetermined time period if the yaw damper disconnect signal is received or the yaw damper activation signal is not received within a predetermined time period after sending the yaw damper disconnect request.

[0013] In one aspect, the method further includes: determining whether the aircraft's rudder is functioning normally based on the aircraft's rudder status signal; and determining whether the yaw function of the rudder is normal based on the rudder command signal and the aircraft's rudder status signal.

[0014] In one embodiment of the present invention, a system for controlling the disconnection of a yaw damper is provided, comprising: a main flight control system including a flight control computer for controlling the rudder of an aircraft; and an automatic flight system, wherein, when the yaw damper of the aircraft is engaged, the automatic flight system determines whether the rudder of the aircraft and the yaw damper data transmission path from the yaw damper to the flight control computer are normal, and if at least one of the rudder of the aircraft and the yaw damper data transmission path is not normal, generates a disconnection pre-position signal, and in response to the disconnection pre-position signal, sends a yaw damper disconnection request to the main flight control system, wherein the main flight control system, in response to the yaw damper disconnection request, determines whether the rudder control link from the flight control computer to the rudder and the yaw function of the rudder are normal, and if at least one of the rudder control link and the yaw function of the rudder is not normal, generates a yaw damper disconnection signal to disconnect the yaw damper of the aircraft.

[0015] On one hand, the automatic flight system determines whether the main flight control system is functioning normally when the aircraft's yaw damper is engaged; and generates the disconnect pre-position signal when the main flight control system is not functioning normally.

[0016] In one respect, at least one of the aircraft's rudder, the yaw damper data transmission path, and the main flight control system malfunctions, including at least one of the following: the rudder fails; the yaw damper data transmission path fails; or the main flight control system enters direct mode.

[0017] In one aspect, in response to the yaw damper disconnect request, the main flight control system further determines whether the transmission link within the main flight control system, the general input / output of the main flight control system, and the input / output of the automatic flight system are normal; and if at least one of the transmission link within the main flight control system, the general input / output of the main flight control system, and the input / output of the automatic flight system is abnormal, then the yaw damper disconnect signal is generated.

[0018] On the one hand, if the rudder control link, the yaw function of the rudder, the transmission link inside the main flight control system, the general input and output of the main flight control system, and the input and output of the automatic flight system are all normal, a yaw damper activation signal is generated to maintain the yaw damper of the aircraft in operation.

[0019] On one hand, if the automatic flight system receives the yaw damper disconnect signal or does not receive the yaw damper connect signal within a predetermined time period after sending the yaw damper disconnect request, the yaw damper of the aircraft is disconnected after the predetermined time period.

[0020] On one hand, the automatic flight system determines whether the aircraft's rudder is functioning normally based on the aircraft's rudder status signal; and the main flight control system determines whether the yaw function of the rudder is normal based on the rudder command signal and the aircraft's rudder status signal. Attached Figure Description

[0021] Figure 1 This is a schematic diagram illustrating the working principle of a yaw damper according to an embodiment of the present invention.

[0022] Figure 2 This is a flowchart of a method for controlling the disconnection of a yaw damper according to an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of a process for controlling the disconnection of a yaw damper according to an embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram illustrating the determination of whether to disconnect the yaw damper according to an embodiment of the present invention. Detailed Implementation

[0025] The present invention will be further described below with reference to specific embodiments and accompanying drawings, but this should not be construed as limiting the scope of protection of the present invention.

[0026] Figure 1 This is a schematic diagram illustrating the working principle of a yaw damper according to an embodiment of the present invention.

[0027] The roll angle, yaw rate, and lateral overload 112 of the aircraft 110 are input to the yaw damper 114. The commands calculated by the yaw damper 114 (e.g., rudder control commands) are sent to the rudder 118 via the flight control computer 116 (referred to as the flight control computer), causing the rudder 118 to deflect, thus achieving yaw damping or coordinated turning, thereby controlling the attitude of the aircraft 110. The link from the yaw damper 114 to the flight control computer 116 can be referred to as the yaw damper data transmission link, and the link from the flight control computer 116 to the rudder 118 can be referred to as the rudder control link. By way of example and not limitation, the flight control computer 116 may be part of the main flight control system.

[0028] Specifically, the rudder control command generated by the yaw damper 114 drives the rudder to deflect slightly via a hydraulic actuator or fly-by-wire system, generating an aerodynamic torque opposite to the yaw direction, thereby suppressing oscillations. For aircraft equipped with a YD switch, the pilot can turn the yaw damper on or off by pressing the YD switch. Additionally, the YD enable signal can be used to activate or deactivate the yaw damper.

[0029] In one existing technology, an ERA signal (main control surface status signal, such as an indication of the elevator, ailerons, rudder, and horizontal stabilizer) is used to determine whether to disconnect the yaw damper. However, disconnecting the yaw damper due to a malfunction of the elevator, ailerons, or horizontal stabilizer will result in a decrease in the aircraft's handling stability.

[0030] Figure 2 This is a flowchart of a method 200 for controlling the disconnection of a yaw damper according to an embodiment of the present invention. In one embodiment, method 200 may be performed by an airborne system, airborne electronic equipment, airborne computer, or other equipment. In another embodiment, method 200 may be performed by the aircraft's flight control system and / or automatic flight system.

[0031] In step 202, the aircraft's yaw damper is engaged and can be in a working state. For example, the pilot can press the YD switch to turn on the power to the yaw damper. In the absence of a fault, the YD Engaged signal YD Engaged = 1, and the yaw damper is in a working state. In one embodiment, if the pilot manually presses the YD switch to turn off the power, the yaw damper stops working due to the power failure.

[0032] In step 204, when the yaw damper is engaged, it is determined whether the aircraft's rudder and the yaw damper data transmission path from the yaw damper to the flight control computer are functioning correctly. If the aircraft's rudder is not functioning correctly and / or the yaw damper data transmission path is not functioning correctly (e.g., malfunction), a disconnect pre-position signal is generated in step 206.

[0033] In an alternative embodiment of step 204, when the yaw damper is engaged, it can also be determined whether the aircraft's main flight control system is functioning correctly. If the main flight control system is malfunctioning, a disconnect pre-position signal can also be generated in step 206. Malfunction of at least one of the aircraft's rudder, yaw damper data transmission path, or main flight control system includes at least one of the following: rudder failure; yaw damper data transmission path failure; or the main flight control system entering direct mode.

[0034] If the aircraft's rudder, yaw damper data transmission path, and main flight control system are all functioning normally, then the yaw damper remains engaged (as in step 202).

[0035] If at least one of the aircraft's rudder, yaw damper data transmission path, or main flight control system malfunctions, a disconnect pre-position signal is generated in step 206. The disconnect pre-position signal indicates the potential for the yaw damper to disconnect.

[0036] In optional step 208, in response to the disconnect pre-position signal, a yaw damper disconnect request may be sent. For example, in one embodiment, the automatic flight system may generate a disconnect pre-position signal and send a yaw damper disconnect request to the main flight control system.

[0037] In step 210, in response to a disconnect pre-position signal or a yaw damper disconnect request, it can be determined whether the rudder control link from the flight control computer to the rudder and the yaw function of the rudder are normal. Optionally, if these parameters are normal, a yaw damper on signal is generated to maintain the aircraft's yaw damper on. If at least one of the rudder control link or the yaw function of the rudder is abnormal, a yaw damper off signal is generated in step 212. In step 214, in response to the yaw damper off signal, the aircraft's yaw damper is disconnected. In one embodiment, in step 214, the automatic flight system or the main flight control system may send a disconnect command to the yaw damper based on the yaw damper off signal (e.g., YDDisengaged = 1), and the yaw damper stops operating in response to the disconnect command. In this case, the YD switch may still be on (i.e., the yaw damper is still powered).

[0038] In an alternative embodiment of step 210, it can be determined whether the rudder control link, the rudder yaw function, the transmission link within the main flight control system, the general inputs and outputs of the main flight control system, and the inputs and outputs of the automatic flight system are normal. If at least one of these parameters is abnormal, a yaw damper disconnect signal is generated to disconnect the aircraft's yaw damper. Optionally, if all these parameters are normal, a yaw damper connect signal is generated to keep the aircraft's yaw damper connected. By way of example and not limitation, step 210 can be performed in response to a disconnect pre-position signal or a yaw damper disconnect request.

[0039] In one embodiment, if a yaw damper disconnect signal is received within a predetermined time period after a yaw damper disconnect request is sent, or if no yaw damper connection signal is received, the aircraft's yaw damper is disconnected after the predetermined time period. This predetermined time period allows signal exchange between devices and prevents repeated states, thus improving the stability of the yaw damper.

[0040] After the yaw damper is disconnected, the pilot can try to restart or reconnect the yaw damper by pressing the YD switch.

[0041] According to the present invention, a dual judgment is introduced in the yaw damper on / off control process. When the aircraft's rudder, yaw damper data transmission path, or main flight control system is abnormal, the system enters a disconnect pre-position state (instead of directly disconnecting YD). The yaw damper is then disconnected only after the rudder control link or the rudder's yaw function is confirmed to be abnormal again, thereby improving the stability of YD.

[0042] In a preferred embodiment, the YD on / off control process incorporates a judgment of the rudder status. When the rudder fails, YD is disconnected. If the elevator, ailerons, horizontal stabilizer, or spoilers fail, it does not affect the functional status of YD, and YD remains on, thus improving the aircraft's handling stability.

[0043] Figure 3 This is a schematic diagram illustrating the determination of whether to disconnect the yaw damper according to an embodiment of the present invention. Figure 3The signal flow between the Automatic Flight System (AFS) 310 and the Primary Flight Control System (PFCS) 330 is illustrated. The AFS provides functions such as autopilot, flight guidance, and autothrottle. The PFCS implements basic flight control (pitch, roll, yaw) to ensure flight stability and maneuverability. The PFCS includes control surfaces, control input devices, a flight control computer, sensors, and other equipment. The PFCS can execute flight commands provided by the AFS. For example, the AFS calculates the target heading and altitude and sends commands to the PFCS. The PFCS determines the control surface deflection method and controls the control surfaces according to the AFS commands, while preventing overshoot. The functions of the PFCS and AFS can be executed by the same computer or the same set of hardware modules, or they can be implemented by independent hardware devices, depending on the specific aircraft design.

[0044] When the yaw damper (YD) is engaged, the automatic flight system 310 determines in step 311 whether the rudder has failed, and generates a signal N1 = 0 if the rudder has failed, and N1 = 1 if the rudder has not failed. For example, the rudder failure can be determined based on the rudder status signal. In optional step 312, the automatic flight system 310 determines whether the PFCS (Primary Flight Control System) has failed, and generates a signal N2 = 0 if the PFCS has failed, and N2 = 1 if the PFCS has not failed. The automatic flight system 310 also determines in step 313 whether the yaw damper data transmission path has failed, and generates a signal N3 = 0 if the yaw damper data transmission path has failed, and N3 = 1 if the yaw damper data transmission path has not failed. Steps 311, 312, and 313 can be executed in any order or concurrently.

[0045] In step 314, the automatic flight system 310 calculates N = N1 + N2 + N3.

[0046] In step 315, the automatic flight system 310 determines whether N equals 3. If N = 3, it means that N1, N2, and N3 are all 1, the rudder and yaw damper data transmission paths and the main flight control system path are all working normally, then the signal YD Capable = 1, indicating that the data source required for the yaw damper to be turned on is available and there is no transmission failure. The signal YDCapable = 1 generated by the automatic flight system 310 is transmitted to the main flight control system 330, and the main flight control system 330 and the automatic flight system 310 keep the yaw damper (YD) on in step 335.

[0047] In step 315, if N≠3, indicating that at least one of N1, N2, and N3 is 0, or that the rudder, yaw damper data transmission path, or main flight control system is malfunctioning (e.g., rudder failure, yaw damper data transmission path failure, or main flight control entering direct mode), then signal YD Capable = 0, triggering pre-positioning signal YD Disengage Arm = 1. YD Disengage Arm is used to pre-position (Arm) the yaw damper disconnection logic, ensuring safe and timely disconnection of the yaw damping function. In the disconnected pre-positioning state, the yaw damper still functions normally.

[0048] According to one embodiment of the present invention, in step 316, when the yaw damper is in the disengagement pre-position state (i.e., YDDisengage Arm=1), the automatic flight system 310 sends a disengagement request YD DisengageRequest=1 to the main flight control system 330.

[0049] In response to the YD Disengage Request = 1, the primary flight control system 330 determines whether the yaw damper should be disconnected. If the determination is that YD does not need to be disconnected, the primary flight control system 330 feeds back YD Engaged = 1 to the automatic flight system 310 within t seconds (step 334), and in step 335, YD remains on. If the determination is that YD needs to be disconnected, the primary flight control system 330 feeds back YD Engaged = 0 to the automatic flight system 310 within t seconds (step 331), and in step 332, the automatic flight system 310 disconnects YD. In one embodiment, if the primary flight control system does not provide feedback within t seconds (e.g., enters direct mode), YD Engaged = 0 is defaulted.

[0050] For example, if the main flight control system 330 issues YD Engaged=1, the automatic flight system 310 keeps the yaw damper open; if the main flight control system 330 issues YD Engaged=0, the automatic flight system 310 sends a disconnect command YD Disengaged=1 to the yaw damper, causing the yaw damper to disconnect.

[0051] In one embodiment, during a time period of t seconds, if the automatic flight system 310 receives feedback from the main flight control system 330 indicating that YD Engaged = 1 or YD Engaged = 0, or if it does not receive feedback from the main flight control system 330, then the YD Disengage Arm can be cleared after t seconds. For example, if the main flight control system 330 enters direct mode, the main flight control system 330 does not issue a YD Engaged signal, the automatic flight system 310 defaults to YD Engaged = 0, and disconnects the yaw damper.

[0052] Figure 4 This is a schematic diagram illustrating the determination of whether to disconnect the yaw damper according to an embodiment of the present invention. In one embodiment, this determination may be implemented by the main flight control system (e.g., flight control computer).

[0053] As described above, when YD is activated, if the pre-position signal YD Disengage Arm = 1, the yaw damper is in the disengaged pre-positioned state. The automatic flight system 310 sends a disengagement request to the main flight control system 330 and waits for t seconds. During the waiting t seconds, the main flight control system 330 (e.g., the flight control computer) performs the following checks:

[0054] a) Is there a fault in the FCC / CAN bus (the transmission link within the main flight control system)? If so, does the fault cause the system to enter direct mode?

[0055] b) Are the IOC / GIOM data paths (input / output of the automatic flight system and general input / output of the main flight control system) all invalid?

[0056] c) Is the rudder control link faulty?

[0057] d) Whether the rudder has lost its yaw function (e.g., the main flight control system performs an internal self-test to determine whether the rudder has lost its yaw function).

[0058] When a, b, c, and d are all normal, meaning the FCC / CAN bus, IOC / GIOM data path, rudder control link, and rudder yaw function are all working properly, it is determined that the yaw damper does not need to be disconnected. Accordingly, the main flight control system issues YDEngaged=1, and YD remains on.

[0059] If any of a, b, c, or d is abnormal, it is determined that the yaw damper needs to be disconnected. The main flight control system issues YDEngaged=0, and YD is disconnected.

[0060] The determination of the waiting time t seconds mainly involves two aspects: firstly, it is determined based on the signal transmission time; secondly, it prevents repeated state fluctuations, allowing YD to be disconnected only after t seconds of stabilization. The waiting time t seconds can be timed using timers in the main flight control system and the automatic flight system. The waiting time t seconds can start from the generation of the pre-position signal YD Disengage Arm = 1, or from the generation or transmission of the disconnection request YD Disengage Request = 1.

[0061] As an example rather than a limitation, the preferred range for time t can be 2 to 10 seconds, 3 to 8 seconds, etc.

[0062] Based on the above-described YD on / off logic, whether YD is disconnected depends only on the rudder state and is unrelated to the states of other main control surfaces. The functional states of YD in the event of control surface failure are shown in Table 1.

[0063]

[0064] According to one embodiment of the present invention, an enable signal (YD capable) and a pre-position signal (YD Disengage Arm) are introduced during the YD on / off control process to establish a handshake with the flight control system. When YD is on, if the pre-position signal is triggered, the yaw damper is in a disengagement pre-positioned state and sends a disengagement request to the flight control system. If the flight control system responds that disengagement is possible, the yaw damper disengages. This dual-judgment approach improves the stability of YD.

[0065] In a preferred embodiment, after the automatic flight system sends a YD disconnect request to the main flight control system, a delay of t seconds is set. During the t-second wait, the flight control computer performs a status check. The determination of the waiting time t seconds is mainly based on two aspects: firstly, it is determined according to the signal transmission time; secondly, it prevents repeated state fluctuations. Disconnection is only allowed after t seconds of stabilization, which prevents jumps and improves the stability of YD.

[0066] In a preferred embodiment, the YD on / off control process incorporates a judgment of the rudder status. When the rudder fails, YD is disconnected. If the elevator, ailerons, horizontal stabilizer, or spoilers fail, it does not affect the functional status of YD, and YD remains on, thus improving the aircraft's handling stability.

[0067] The various steps and modules of the methods and apparatus described above can be implemented in hardware, software, or a combination thereof. If implemented in hardware, the various illustrative steps, modules, and circuits described in connection with this disclosure can be implemented or executed using a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or other programmable logic components, hardware components, or any combination thereof. A general-purpose processor can be a processor, microprocessor, controller, microcontroller, or state machine, etc. If implemented in software, the various illustrative steps and modules described in connection with this disclosure can be stored as one or more instructions or codes on a computer-readable medium or transmitted. Software modules implementing the various operations of this disclosure can reside in a storage medium, such as RAM, flash memory, ROM, EPROM, EEPROM, registers, hard disk, removable disk, CD-ROM, cloud storage, etc. The storage medium can be coupled to a processor so that the processor can read and write information from / to the storage medium and execute the corresponding program modules to implement the various steps of this disclosure.

[0068] The numerical values ​​given in the various embodiments are merely examples and are not intended to limit the scope of the invention. In practice, the specific parameters of each component and various thresholds can be appropriately set as needed, and are not limited to the specific values ​​given as examples herein. Furthermore, as a whole technical solution, there are other components or steps not listed in the claims or specification of this invention. Moreover, a single name for a component does not preclude other names for that component.

[0069] It should also be noted that these embodiments may be described as processes depicted as flowcharts, flow diagrams, structure diagrams, or block diagrams. Although a flowchart may describe the operations as a sequential process, many of these operations can be executed in parallel or concurrently. Furthermore, the order of these operations can be rearranged.

[0070] The disclosed methods, apparatuses, and systems should not be limited in any way. Rather, this disclosure covers all novel and non-obvious features and aspects of the various disclosed embodiments (individually and in various combinations and sub-combinations of each other). The disclosed methods, apparatuses, and systems are not limited to any particular aspect or feature or combination thereof, and no disclosed embodiment is required to have any one or more specific advantages or to solve any particular or all technical problems.

[0071] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the scope of protection of the present invention.

Claims

1. A method for controlling the disconnection of a yaw damper, characterized in that, include: When the aircraft's yaw damper is engaged, determine whether the aircraft's rudder and the yaw damper data transmission path from the yaw damper to the flight control computer are normal. If at least one of the data transmission paths of the aircraft's rudder and the yaw damper is not functioning properly, a disconnect pre-positioning signal is generated. In response to the disconnect pre-position signal, determine whether the rudder control link from the flight control computer to the rudder and the yaw function of the rudder are normal; as well as If at least one of the rudder control link and the rudder yaw function is abnormal, a yaw damper disconnect signal is generated to disconnect the aircraft's yaw damper.

2. The method for controlling the disconnection of the yaw damper as described in claim 1, characterized in that, Also includes: When the yaw damper of the aircraft is engaged, determine whether the main flight control system of the aircraft is functioning properly. The disconnect pre-position signal is generated when the main flight control system malfunctions.

3. The method for controlling the disconnection of the yaw damper as described in claim 2, characterized in that, At least one of the aircraft's rudder, the yaw damper data transmission path, and the main flight control system malfunctions, including at least one of the following: The rudder is malfunctioning; The yaw damper data transmission path is invalid; or The main flight control system enters direct mode.

4. The method for controlling the disconnection of the yaw damper as described in claim 1, characterized in that, Also includes: In response to the disconnection pre-positioning signal, it is further determined whether the transmission link inside the main flight control system, the general input and output of the main flight control system, and the input and output of the automatic flight system are normal; as well as If at least one of the transmission link within the main flight control system, the general input / output of the main flight control system, or the input / output of the automatic flight system is abnormal, a yaw damper disconnect signal is generated.

5. The method for controlling the disconnection of the yaw damper as described in claim 4, characterized in that, Also includes: If the rudder control link, the rudder yaw function, the transmission link inside the main flight control system, the general input / output of the main flight control system, and the input / output of the automatic flight system are all normal, a yaw damper activation signal is generated to maintain the yaw damper of the aircraft in operation.

6. The method for controlling the disconnection of the yaw damper as described in claim 1, characterized in that, Also includes: In response to the disconnect pre-position signal, a yaw damper disconnect request is sent; If the yaw damper disconnect signal is received within a predetermined time period after the yaw damper disconnect request is sent, or if the yaw damper connection signal is not received, the yaw damper of the aircraft is disconnected after the predetermined time period.

7. The method for controlling the disconnection of the yaw damper as described in claim 1, characterized in that, Also includes: The aircraft's rudder status signal is used to determine whether the rudder is working properly. as well as The yaw function of the rudder is determined based on the rudder command signal and the rudder status signal of the aircraft.

8. A system for controlling the disconnection of a yaw damper, characterized in that, include: A main flight control system, which includes a flight control computer for controlling the aircraft's rudder; An automatic flight system, when the aircraft's yaw damper is engaged, determines whether the aircraft's rudder and the yaw damper data transmission path from the yaw damper to the flight control computer are normal. If at least one of the aircraft's rudder or the yaw damper data transmission path is not functioning correctly, the system generates a disconnect pre-position signal and, in response to the disconnect pre-position signal, sends a yaw damper disconnect request to the main flight control system. The main flight control system, in response to the yaw damper disconnect request, determines whether the rudder control link from the flight control computer to the rudder and the yaw function of the rudder are normal, and if at least one of the rudder control link and the yaw function of the rudder is abnormal, generates a yaw damper disconnect signal to disconnect the yaw damper of the aircraft.

9. The system for controlling the disconnection of the yaw damper as described in claim 8, characterized in that, When the aircraft's yaw damper is engaged, the automatic flight system determines whether the main flight control system is functioning properly. The disconnect pre-position signal is generated when the main flight control system malfunctions.

10. The system for controlling the disconnection of the yaw damper as described in claim 9, characterized in that, At least one of the aircraft's rudder, the yaw damper data transmission path, and the main flight control system malfunctions, including at least one of the following: The rudder is malfunctioning; The yaw damper data transmission path is invalid; or The main flight control system enters direct mode.

11. The system for controlling the disconnection of the yaw damper as described in claim 8, characterized in that, In response to the yaw damper disconnection request, the main flight control system further determines whether the transmission links within the main flight control system, the general inputs and outputs of the main flight control system, and the inputs and outputs of the automatic flight system are normal. as well as If at least one of the transmission link within the main flight control system, the general input / output of the main flight control system, or the input / output of the automatic flight system is abnormal, a yaw damper disconnect signal is generated.

12. The system for controlling the disconnection of the yaw damper as described in claim 11, characterized in that, If the rudder control link, the rudder yaw function, the transmission link inside the main flight control system, the general input / output of the main flight control system, and the input / output of the automatic flight system are all normal, a yaw damper activation signal is generated to maintain the yaw damper of the aircraft in operation.

13. The method for controlling the disconnection of the yaw damper as described in claim 8, characterized in that, Also includes: If the automatic flight system receives the yaw damper disconnect signal or does not receive the yaw damper activation signal within a predetermined time period after sending the yaw damper disconnect request, then disconnects the aircraft's yaw damper after the predetermined time period.

14. The system for controlling the disconnection of the yaw damper as described in claim 8, characterized in that, The automatic flight system determines whether the aircraft's rudder is functioning properly based on the aircraft's rudder status signal; and The main flight control system determines whether the yaw function of the rudder is normal based on the rudder command signal and the rudder status signal of the aircraft.

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