Method for outputting control instructions of a flight control computer

Abstract

The present disclosure relates to a method of outputting flight control computer control instructions, the method being performed by a first computer's back-up mode link, the method comprising: calculating back-up mode control instructions; receiving from a second computer control instructions from a primary computer, the control instructions being instructions for the first computer transmitted by the primary computer to the second computer; and outputting the control instructions as back-up mode link instructions if the control instructions from the primary computer are valid, otherwise outputting the back-up mode control instructions as back-up mode link instructions.

Description

Technical Field

[0001] This disclosure relates to fly-by-wire flight control of an aircraft, and in particular to a method for outputting flight control computer control commands. Background Technology

[0002] Generally, an aircraft's flight control system includes normal mode and degraded mode. In normal mode, the control law is calculated by a main computer and sent to the actuation system through four secondary computers, with no signal communication between the four secondary computers. Under specific fault conditions, the secondary computers will switch from normal mode to degraded mode. In degraded mode, the control law is calculated by the secondary computer and sent directly to the actuation system connected to its backend to control the corresponding control surfaces. Since several actuators on the same control surface operate in a master-master or master-master-master configuration and are connected to different secondary computers, if the operating modes of the different secondary computers connected to the same control surface are inconsistent, it will cause different actuators on the same control surface to respond to different control mode commands. This will cause the control surface to oscillate due to mixed-mode force conflict, which will not only reduce the aircraft's control performance but also affect the fatigue life of the control surfaces and even affect the aircraft's flight safety.

[0003] Thus, due to the current flight control system architecture, when a single subcomputer enters degraded mode, the flight control system enters a hybrid mode working scenario. This not only causes significant force conflicts on the control surfaces, affecting their fatigue life, but also leads to a decrease in the aircraft's handling performance, making it unable to meet the "fail-to-operate" requirements of CAT IIIb automatic landing.

[0004] This disclosure addresses, but is not limited to, the many factors mentioned above. Summary of the Invention

[0005] To address this, this disclosure proposes a method for outputting flight control computer control commands. Based on the existing master computer-secondary computer architecture, a unidirectional communication bus is added between the secondary computers, connecting the normal mode link of the master computer to the degraded mode link of the secondary computer. This bus is used to forward normal control law control surface position commands from the master computer. After a single (or multiple) secondary computer enters degraded mode (sometimes also called direct mode), as long as the degraded mode link of that secondary computer can still receive valid normal control law control surface position commands through this unidirectional data bus, it can still provide normal control law control surface position commands to the actuation system through the degraded mode link. This avoids serious force conflicts on the control surfaces caused by redundant secondary computers outputting mixed mode commands.

[0006] According to a first aspect of this disclosure, a method for outputting flight control computer control commands is provided, the method being executed by a degraded mode link of a primary computer, the method comprising: calculating degraded mode control commands; receiving control commands from a primary computer from a secondary computer, the control commands being instructions transmitted from the primary computer to the secondary computer for the primary computer; and, if the control commands from the primary computer are valid, outputting the control commands as degraded mode link commands, otherwise outputting the degraded mode control commands as degraded mode link commands.

[0007] According to one embodiment, the control command is received from the second computer via a communication line to the second computer for transmitting control commands.

[0008] According to another embodiment, the communication line is a unidirectional communication bus from the normal mode link of the second computer to the degraded mode link of the first computer.

[0009] According to yet another embodiment, the validity of the control instructions from the host computer is determined based on a validity flag.

[0010] According to another embodiment, when the second computer is in normal mode, the validity flag is set to valid; when the second computer is in degraded mode or receives an instruction from the main computer to enter degraded mode, the validity flag is set to invalid.

[0011] According to another embodiment, the instruction from the master computer to enter degrade mode is issued by the master computer to each secondary computer when the master computer detects that it is unable to send control instructions to all secondary computers that are still in operation.

[0012] According to yet another embodiment, the first computer and the second computer are located in the same compartment area.

[0013] According to yet another embodiment, the degradation mode link instruction is the first time the computer outputs it to the actuation system in degradation mode.

[0014] According to a second aspect of this disclosure, a secondary computer for a flight control system of an aircraft is provided, the secondary computer including a processing means configured to perform the method according to a first aspect of this disclosure.

[0015] According to a third aspect of this disclosure, an aircraft is provided, including the secondary computer described in the second aspect of this disclosure.

[0016] The aspects generally include, as substantially as described herein with reference to the accompanying drawings and as explained by the drawings, methods, apparatus, systems, computer program products, and processing systems.

[0017] The foregoing has broadly outlined the features and technical advantages of the examples according to this disclosure so that the following detailed description may be better understood. Additional features and advantages will be described thereafter. The disclosed concepts and specific examples can be readily used as the basis for modifying or designing other structures for implementing the same purposes as this disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The characteristics of the concepts disclosed herein, in both their organization and manner of operation, and their associated advantages, will be better understood by considering the following description in conjunction with the accompanying drawings. Each drawing is provided for illustrative and descriptive purposes and does not define any limitation on the claims. Attached Figure Description

[0018] To gain a more detailed understanding of the features described above in this disclosure, reference can be made to various aspects of the above-briefly summarized content, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only certain typical aspects of this disclosure and should not be considered as limiting its scope, as other equivalent aspects are permissible in this description. Identical reference numerals in different drawings may identify the same or similar elements.

[0019] Figure 1 A flowchart is shown of a method for outputting flight control computer control commands according to an embodiment of the present disclosure;

[0020] Figure 2 A schematic diagram of a cross-connection architecture between secondary computers according to an exemplary embodiment of the present disclosure is shown;

[0021] Figure 3 A schematic diagram of a subcomputer for a flight control system of an aircraft, according to one aspect of this disclosure, is shown; and

[0022] Figure 4 A schematic diagram of an aircraft according to an example embodiment of the present disclosure is shown. Detailed Implementation

[0023] The inventors recognized that current fly-by-wire flight control systems used in aircraft (especially civil aircraft) include cockpit controls, a flight control computer, flight control actuator assemblies for manipulating the corresponding control surfaces, and so on. The flight control computer typically includes a redundant main computer and secondary computers. Each of the redundant secondary computers corresponds to a control channel and is configured to independently receive cockpit control commands from the cockpit controls and perform control law calculations in the event of a main computer failure. Each secondary computer is communicatively connected to its corresponding flight control actuator assembly, ensuring that the minimum flight safety requirements of the aircraft are met when each control surface operates independently on a single control channel.

[0024] The inventors also recognized that the existing aircraft design had the following problems:

[0025] When a single flight control system subcomputer enters degraded mode, it will cause the entire flight control system to enter a hybrid control mode. At this time, the aircraft control performance can only meet the "fail-safe" working requirements of the automatic flight function, and thus cannot support the "fail-operation" requirements of the CATIIIb automatic landing system.

[0026] For control surfaces operating in a master-master or master-master-master configuration, if a single flight control system secondary computer enters a degraded mode, multiple actuators on the same control surface may experience continuous and significant control surface force conflicts and oscillations due to responses to commands from different control modes. This can affect the fatigue life of the control surface, potentially impacting flight safety and increasing maintenance work such as structural flaw detection, resulting in additional operating costs.

[0027] The inventors also recognized that existing force conflict solutions, which primarily rely on rudder surface force conflict equilibrium control laws to mitigate and force conflict oscillation monitors, have shortcomings, such as:

[0028] When the secondary computer is in degraded mode, it cannot respond to the power conflict mitigation command from the primary computer, and therefore does not have the power conflict mitigation function.

[0029] For control surfaces with a 2-actuation redundancy configuration, the force conflict oscillation monitor cannot determine the source of the fault, so it will simultaneously disconnect both actuators on the control surface, causing a significant decrease in the aircraft's maneuverability.

[0030] For a control surface with a 3-actuation redundancy configuration, the actuator that triggers the monitor is controlled by the secondary computer in degraded mode, so it is impossible to control and disconnect the actuator, and the control surface will continue to struggle with force.

[0031] When the force conflict oscillation monitor is triggered, the control surface has already suffered fatigue damage, and the aircraft still needs to undergo structural flaw detection and other maintenance work, which generates additional operating costs.

[0032] etc.

[0033] Generally, an aircraft's flight control system includes normal mode and degraded mode. In normal mode, the control law is calculated by a main computer and sent to the actuation system through four secondary computers. There is no signal communication between the four secondary computers. Each secondary computer includes two links: a normal mode link and a degraded mode link. The normal mode link receives control commands from the main computer and outputs normal mode link commands, while the degraded mode link calculates degraded mode control commands and outputs those commands as degraded mode link commands. Subsequently, the secondary computer can output commands from one of these two links to the corresponding actuation system based on whether it is in normal mode or degraded mode. That is, when the secondary computer is in normal mode, it selects the normal mode link command from the normal mode link to control the corresponding actuation system; when the secondary computer is in degraded mode, it selects the degraded mode link command from the degraded mode link to control the corresponding actuation system.

[0034] Under specific fault conditions, the secondary computer will switch from normal mode to degraded mode. In degraded mode, the control law is calculated by the secondary computer (i.e., its degraded mode link) and sent directly to the actuation system connected to the back end of the secondary computer to control the corresponding control surface. Since several actuators on the same control surface operate in a master-master or master-master-master configuration and are connected to different secondary computers, if the operating modes of different secondary computers on the same control surface are inconsistent (for example, one secondary computer is in degraded mode while another is in normal mode), it will cause different actuators on the same control surface to respond to different control mode commands. This will cause the control surface to oscillate due to mixed-mode force conflict, thereby reducing the control performance of the aircraft, affecting the fatigue life of the control surface, and even affecting the flight safety of the aircraft.

[0035] Thus, the inventors realized that, due to the current flight control system architecture, when a single subcomputer enters degraded mode, the flight control system enters a hybrid mode working scenario. This not only causes greater force disputes on the control surfaces, affecting their fatigue life, but also leads to a decrease in the aircraft's handling performance, making the aircraft unable to meet the "fail-to-operate" requirements of CAT IIIb automatic landing.

[0036] To address this, this disclosure proposes a method for outputting flight control computer control commands. Based on the existing master computer-secondary computer architecture, a unidirectional communication bus is added between the secondary computers, connecting the normal mode link of the master computer to the degraded mode link of the secondary computer. This bus is used to forward normal control law control surface position commands from the master computer. This allows a single (or multiple) secondary computer to enter degraded mode (sometimes also called direct mode). As long as the degraded mode link of that secondary computer can still receive valid normal control law control surface position commands through this unidirectional data bus, it can still provide normal control law control surface position commands to the actuators through the degraded mode link. This avoids serious force conflicts on the control surfaces caused by redundant secondary computers outputting mixed mode commands.

[0037] Therefore, the method disclosed herein enables:

[0038] a) It avoids force conflicts in the flight control hybrid mode, reduces maintenance and repair work, and lowers operating costs;

[0039] b) Even after a single subcomputer enters degraded mode, the integrity of its back-end actuators is still preserved, improving aircraft maneuverability and supporting the CAT IIIb automatic landing system to meet the "fail-to-operate" requirement.

[0040] c) Improved availability in normal mode and reduced the probability of the system entering degraded mode due to computer combinatorial failure.

[0041] d) Preferably, the communication line of this disclosure is configured as a unidirectional communication line from a normal mode link of a secondary computer to a degraded mode link of an adjacent secondary computer, so that the degraded mode link of one secondary computer will not affect the normal mode link of other secondary computers.

[0042] The detailed description that follows, taken in conjunction with the accompanying drawings, is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein can be practiced. This detailed description includes specific details to provide a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details.

[0043] refer to Figure 1 The diagram shows a flowchart of a method 100 for outputting flight control computer control commands according to an embodiment of the present disclosure.

[0044] As shown in the figure, method 100 may include block 110, which calculates the degradation mode control command.

[0045] In one embodiment of this disclosure, each secondary computer includes two links: a normal mode link and a degraded mode link. The normal mode link receives control commands from the primary computer and outputs these commands (typically referred to as normal mode link commands) for the secondary computer to output to the corresponding actuation system to control the corresponding control surfaces in normal mode. The degraded mode link calculates degraded mode control commands and outputs these commands as degraded mode link commands for the secondary computer to output to the corresponding actuators in degraded mode. Subsequently, the secondary computer can output commands from one of these two links to the corresponding actuation system based on whether it is in normal mode or degraded mode. Thus, in one embodiment, method 100 can be executed by the degraded mode link of the primary computer.

[0046] Continue to refer to Figure 1 Method 100 may include, in block 120, receiving control instructions from the host computer from the second computer. In one embodiment of this disclosure, the control instructions are instructions from the host computer to the second computer directed at the first computer. Thus, in this embodiment, the second computer receives not only control instructions for itself from the host computer, but also control instructions for the first computer for forwarding to the first computer (more precisely, a degraded mode link forwarded to the first computer).

[0047] In another embodiment of this disclosure, control commands for the first computer are received from the second computer via a communication line for transmitting control commands. In this embodiment, a communication line for transmitting control commands is provided between the first and second computers. In a preferred embodiment of this disclosure, this communication line is a unidirectional communication bus connecting the normal mode link of the second computer to the degraded mode link of the first computer, enabling control commands for the first computer to be transmitted from the normal mode link of the second computer to the degraded mode link of the first computer. Therefore, in this preferred embodiment, it can be ensured that the normal mode link of the second computer is not affected by the degraded mode link of the first computer (because their communication line is unidirectional), thereby reducing system complexity and improving system robustness.

[0048] In yet another embodiment of this disclosure, the first computer can also serve as "redundancy" for the second computer. In this embodiment, the first computer receives control commands not only for itself from the host computer but also for the second computer, for which it forwards the commands. According to this embodiment, the control commands for the second computer are forwarded via a unidirectional communication bus from the normal mode link of the first computer to the degraded mode link of the second computer. Thus, in this embodiment, it can be ensured that the normal mode link of the first computer is not affected by the degraded mode link of the second computer (because their communication lines are unidirectional), thereby reducing system complexity and improving system robustness. In this way, the first and second computers can serve as "redundancy" for each other, thereby improving the availability of control commands from the host computer (i.e., the availability of normal mode).

[0049] In another embodiment of this disclosure, the first computer and the second computer can be "adjacent secondary computers," for example, the first computer and the second computer can be located in the same compartment area. In this way, the communication bus between the two secondary computers can be shortened as much as possible, thereby saving bus length and minimizing the weight of the additional bus required.

[0050] refer to Figure 2 It illustrates a schematic diagram of a cross-connection architecture between subcomputers according to an example embodiment of the present disclosure.

[0051] like Figure 2 As shown, the flight control system may include several main computers (e.g., three) and four secondary computers ( Figure 2 The subcomputers are labeled as Subcomputer 1, Subcomputer 2, Subcomputer 3, and Subcomputer 4. Figure 2 In this configuration, secondary computer 1 and secondary computer 2 are adjacent secondary computers (both are in compartment area 1), and secondary computer 3 and secondary computer 4 are adjacent secondary computers (both are in compartment area 2).

[0052] refer to Figure 2 As can be seen, a unidirectional communication bus exists between the normal mode link of secondary computer 1 and the degraded mode link of secondary computer 2, enabling secondary computer 1 to forward control commands received from the host computer for secondary computer 2 to secondary computer 2; similarly, a unidirectional communication bus exists between the normal mode link of secondary computer 2 and the degraded mode link of secondary computer 1, enabling secondary computer 2 to forward control commands received from the host computer for secondary computer 1 to secondary computer 1. Secondary computers 3 and 4 are configured similarly, and will not be described further here.

[0053] Generally speaking, and also as Figure 2As shown, the four secondary computers are arranged in pairs in different compartments of the aircraft to improve the independence between them and avoid problems such as common-mode failures. Therefore, in a preferred embodiment of this disclosure, a secondary computer and its adjacent secondary computer are located in the same compartment. In this preferred embodiment, the added communication lines can have a shorter length, thereby effectively reducing the overall weight while maintaining the independence between the secondary computers to the greatest extent possible. In a further preferred embodiment, a secondary computer and its adjacent secondary computer are respectively connected to a corresponding actuator for manipulating at least one common control surface. For example, the two actuators of an aileron can operate in a master-master configuration, and the secondary computer and its adjacent secondary computer are respectively connected to one of the two actuators of the same aileron. In yet another embodiment of this disclosure, the control surface can be an aileron, rudder, elevator, etc.

[0054] Continue to refer to Figure 1 If the control command from the host computer is valid, method 100 can proceed to block 130, where the received control command is output as a degraded mode link command; otherwise, if the control command from the host computer is invalid, method 100 can proceed to block 140, where the calculated degraded mode control command is output as a degraded mode link command.

[0055] In one embodiment of this disclosure, the validity of control commands from the host computer is determined based on a validity flag. For example, the host computer transmits a validity flag along with the control commands, and this flag is set to valid when the system is in normal mode and set to invalid when the system is in degraded mode. Thus, when a secondary computer receives a control command from the host computer, it can determine whether the received control command is valid based on this validity flag (e.g., a validity flag bit can be set to 0 for invalid and 1 for valid). According to this example, when the degraded mode link of the first computer receives a forwarded control command for the first computer from the normal mode link of the second computer, the degraded mode link of the first computer can determine whether the control command is valid based on this validity flag.

[0056] In an alternative embodiment, the validity flag can be set to valid when the second computer is in normal mode; and can be set to invalid when the second computer is in degraded mode or receives an instruction from the host computer to enter degraded mode.

[0057] For example, after receiving a control command for the first computer but before forwarding it to the first computer, the second computer can change its validity flag or add a new validity flag based on its own state. For instance, if the second computer is in degraded mode, it can change the validity flag of the control command it receives from the master computer for the first computer to invalid; if the second computer is in normal mode, it may not change the validity flag of the control command it receives from the master computer for the first computer. Alternatively, if the second computer is in degraded mode, it can add a new validity flag to the control command it receives from the master computer for the first computer, indicating that the control command is invalid; if the second computer is in normal mode, it can add a new validity flag to the control command it receives from the master computer for the first computer, indicating that the control command is valid. According to this example, when the first computer receives a control command forwarded by the second computer, it considers the control command valid only if both the original validity flag (set by the master computer) and the new validity flag (added by the second computer) indicate that the command is valid.

[0058] In yet another alternative embodiment of this disclosure, the validity flag may also represent an indication of the operating mode of the second computer (i.e., the adjacent second computer). For example, the second computer may indicate to the first computer whether it is in normal mode, and if the second computer is in normal mode, the validity flag may be considered to be set to valid, while if the second computer is in abnormal mode (degraded mode or fault mode), the validity flag may be considered to be set to invalid.

[0059] In another embodiment of this disclosure, the secondary computer can monitor its own operational status in real time and, in the event of a specific fault, put itself into a degraded mode, thereby detecting this. Alternatively, the secondary computer can determine that it needs to enter a degraded mode after receiving an instruction from the master computer to enter degraded mode. According to this embodiment, the instruction from the master computer to enter degraded mode is issued by the master computer to each secondary computer when the master computer detects that it cannot send control instructions to all the secondary computers that are still operating. For example, see reference... Figure 2There are four secondary computers: secondary computer 1 and secondary computer 2 are adjacent to each other, and secondary computer 3 and secondary computer 4 are adjacent to each other. If secondary computer 1 and secondary computer 2, which are adjacent to each other, are both in abnormal mode (here, abnormal mode includes degraded mode and fault mode), the master computer can determine that it has detected that it cannot send control commands to all the secondary computers that are still working, and thus issue instructions to each secondary computer to enter degraded mode. However, it will be understood that if secondary computer 1 and secondary computer 3 are in degraded mode, while secondary computer 2 and secondary computer 4 are in normal mode, then secondary computer 1 can still receive forwarded control commands from the master computer through its adjacent secondary computer 2, and secondary computer 3 can still receive forwarded control commands from the master computer through its adjacent secondary computer 4. Thus, the master computer can determine that it can still send control commands to all the secondary computers that are still working. It can be seen that as long as the secondary computers that are adjacent to each other are not all in abnormal mode, the method and system of this disclosure can still work in normal mode.

[0060] It will be understood that the degraded mode link instruction is output by the secondary computer to the actuation system in degraded mode. Therefore, when the secondary computer determines that it is in degraded mode, method 100 may further include outputting a degraded mode link instruction from the degraded mode link to control the corresponding actuator; or when the secondary computer determines that it is in normal mode, method 100 may further include outputting a normal mode link instruction from the normal mode link to control the corresponding actuator.

[0061] In the existing system, in normal mode, the control law is calculated by a master computer and sent to the actuator system via four secondary computers to control the corresponding control surfaces. There is no signal interconnection between the four secondary computers (i.e., there are no communication lines between them for transmitting control commands). In degraded mode, the control law is calculated by the degraded mode link of the secondary computer and ultimately sent to the actuator system connected to the back end of that secondary computer. Here, the degraded mode link command output by the degraded mode link is always the degraded mode control command it has calculated.

[0062] Conversely, in the embodiments of this disclosure, the degraded mode link instruction can be a control instruction received from the master computer and forwarded by an adjacent secondary computer (if the control instruction from the master computer is valid), or a calculated degraded mode control instruction (if the control instruction from the master computer is invalid). Thus, when a secondary computer is in degraded mode while its adjacent secondary computers are in normal mode, the degraded mode link instruction output by that secondary computer will be a control instruction from the master computer forwarded by the adjacent secondary computer, rather than a degraded mode control instruction calculated by its own degraded mode link. This enhances the availability of control instructions from the master computer, ensures the consistency and synchronization of system responses to control instructions, and preserves the integrity of the actuation system.

[0063] Thus, even when only one of the two adjacent secondary computers is in degraded mode, normal mode control of the actuation system is still possible. Only when both secondary computers are in degraded mode will the degraded mode link output the calculated degraded mode control commands for controlling the associated actuation system. This improves the availability of normal mode, enhances the maneuverability of the control surfaces in the event of a failure in one of the two adjacent secondary computers, supports CAT IIIb automatic landing, and also avoids force disputes.

[0064] It will become clear that, despite the combination Figure 1 The steps are shown and described sequentially, but these steps may be performed in a different order or in parallel, such as steps 110 and 120, which may be performed in reverse order or in parallel.

[0065] The following is a specific implementation example of the method disclosed herein:

[0066] To meet system function allocation requirements, the secondary computer is internally divided into three partitions: Normal Mode Partition (NM), used to receive control commands (nm_cmd) from the master computer and output normal mode link commands (i.e., control commands from the master computer); Degraded Mode Partition (DM), used to calculate degraded mode control commands locally and receive control commands from the master computer forwarded by neighboring secondary computers, and output degraded mode link commands (either the calculated degraded mode control commands or the received control commands forwarded by neighboring secondary computers from the master computer); Common Partition (CP), used to determine whether to output normal mode link commands or degraded mode link commands based on the secondary computer's operating mode (local_ace_nm). When the secondary computer is operating in normal mode (local_ace_nm=1), it outputs normal mode link commands from the NM partition to actuate system control; when the secondary computer is not operating in normal mode (local_ace_nm=0), it outputs degraded mode link commands from the DM partition to actuate system control.

[0067] Adjacent secondary computers forward control commands from the primary computer to each other. This control command (nm_cmd_from_adjacent_ace), along with its validity flag (nm_cmd_from_adjacent_ace_vld), is directly passed from the secondary computer's NM partition to the adjacent secondary computer's DM partition. If the secondary computer is operating in normal mode, it sets the validity flag (nm_cmd_from_adjacent_ace_vld) of the forwarded control command to valid. Upon receiving the forwarded control command and its corresponding validity flag, the DM partition of the adjacent secondary computer, if confirming that the validity flag is set to valid (i.e., the control command is valid), outputs the received forwarded control command (nm_cmd_from_adjacent_ace). The command output selection varies depending on the secondary computer's operating conditions, as follows:

[0068] a) In normal mode, the secondary computer selects the master computer command output by the NM partition (i.e., normal mode link command).

[0069] b) In degraded mode, the secondary computer selects the degraded mode link instruction output by the DM partition; when the adjacent secondary computer is in normal mode, this degraded mode link instruction is a control instruction forwarded by the adjacent secondary computer.

[0070] In this way, when a secondary computer enters degraded mode and its adjacent secondary computer is in normal mode, the CP partition ultimately outputs the control commands from the DM partition, ensuring the consistency and synchronization of the system's response to normal mode commands, thus preserving the integrity of the operating system.

[0071] refer to Figure 3 The diagram shows a subcomputer 300 for a flight control system of an aircraft according to one aspect of the present disclosure.

[0072] like Figure 3 As shown, the secondary computer 300 may include a processing device 305. In various embodiments, the processing device 305 may be configured to perform methods according to various embodiments of the present disclosure, such as combining Figure 1-2 Method 100 as described.

[0073] Figure 4 A schematic diagram of an aircraft 400 according to an example embodiment of the present disclosure is shown. In one embodiment of the present disclosure, the aircraft 400 may include a secondary computer as described in various embodiments of the present disclosure, such as in conjunction with... Figure 3 The aforementioned secondary computer 300.

[0074] Therefore, this disclosure proposes a method for outputting flight control computer control commands. Based on the existing master-secondary computer architecture, a cross-channel unidirectional cross-link communication bus is added between the secondary computers, connecting the normal mode link to the degraded mode link. This bus forwards normal control law control surface position commands (i.e., control commands from the master computer) from the master computer. Even after one (or more) secondary computers enter degraded mode, as long as the degraded mode link of that secondary computer can still receive valid cross-channel unidirectional cross-link communication bus data (control commands forwarded from the master computer by its adjacent secondary computers), it can still provide normal control law commands to the actuation system through the degraded mode link. Thus, the technical solution of this disclosure achieves the following technical effects:

[0075] a) It avoids force conflicts in the flight control hybrid mode, reduces maintenance and repair work, and lowers operating costs;

[0076] b) Even after the computer enters degraded mode, it still retains the integrity of its back-end actuation system to a certain extent, improving the aircraft's maneuverability and supporting the CAT IIIb automatic landing system to meet the "fail-to-operate" requirements.

[0077] c) Improved availability in normal mode and reduced the probability of the system entering degraded mode due to failure of a combination of secondary computers (i.e., adjacent secondary computers).

[0078] The above detailed description includes references to the accompanying drawings, which form part of the detailed description. The drawings illustrate specific embodiments that can be practiced by way of illustration. These embodiments are also referred to herein as “examples.” Such examples may include elements other than those shown or described. However, examples including the shown or described elements are also contemplated. Furthermore, examples of any combination or arrangement of those elements shown or described are contemplated, or with reference to specific examples (or one or more aspects thereof) shown or described herein, or with reference to other examples (or one or more aspects thereof) shown or described herein.

[0079] In the appended claims, the terms “comprising” and “including” are open-ended, meaning that a system, apparatus, article of manufacture, or process containing elements other than those listed after such terms in a claim is still considered to fall within the scope of that claim. Furthermore, in the appended claims, the terms “first,” “second,” and “third,” etc., are used merely as designations and are not intended to indicate a numerical order of their contents.

[0080] Furthermore, the order of operations described in this specification is exemplary. In alternative embodiments, the operations may be performed in a different order than that shown in the accompanying drawings, and the operations may be combined into a single operation or broken down into more operations.

[0081] The above description is intended to be illustrative and not restrictive. For example, the examples described above (or one or more aspects thereof) may be used in conjunction with other embodiments. Other embodiments may be used by those skilled in the art after reviewing the above description. The abstract allows the reader to quickly determine the nature of this technical disclosure. This abstract is submitted and it is understood that it is not intended to interpret or limit the scope or meaning of the claims. Furthermore, in the above detailed description, various features may be grouped together to make this disclosure flow smoothly. However, the claims may not state every feature disclosed herein, as embodiments may characterize a subset of said features. Furthermore, embodiments may include fewer features than those disclosed in a particular example. Therefore, the appended claims are thus incorporated into the detailed description, with each claim existing independently as a separate embodiment. The scope of the embodiments disclosed herein should be determined by reference to the full scope of the appended claims and equivalents of such claims.

Claims

1. A method for outputting flight control computer control commands, the method being executed by a degraded mode link of the initial computer, the method comprising: Calculate the degradation mode control instructions; The second computer receives control commands from the main computer, which are commands transmitted from the main computer to the second computer for the first computer, and are normal control law rudder position commands. as well as If the control command from the host computer is valid, the control command is output as a degraded mode link command; otherwise, the degraded mode control command is output as a degraded mode link command.

2. The method according to claim 1, characterized in that, The control commands are received from the second computer via a communication line used for transmitting control commands.

3. The method according to claim 2, characterized in that, The communication line is a unidirectional communication bus connecting the normal mode link of the second computer to the degraded mode link of the first computer.

4. The method according to claim 1, characterized in that, The validity of the control commands from the host computer is determined based on a validity flag.

5. The method according to claim 4, characterized in that, When the second computer is in normal mode, the validity flag is set to valid; when the second computer is in degraded mode or receives an instruction from the main computer to enter degraded mode, the validity flag is set to invalid.

6. The method according to claim 5, characterized in that, The instruction to enter degrade mode from the master computer is issued by the master computer to each secondary computer when the master computer detects that it is unable to send control instructions to all secondary computers that are still in operation.

7. The method according to claim 1, characterized in that, The first computer and the second computer are located in the same compartment area.

8. The method according to claim 1, characterized in that, The degradation mode link instruction is the first time the computer outputs it to the actuation system in degradation mode.

9. A secondary computer for a flight control system of an aircraft, the secondary computer comprising a processing unit configured to perform the method according to any one of claims 1-8.

10. An aircraft comprising a subcomputer as claimed in claim 9.

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