A flight control method and device for a distributed flight control system

Abstract

This invention provides a flight control method and apparatus for a distributed flight control system. The flight control system includes: a quadruple-redundant aircraft management computer, a pilot interface unit (PIU), and a remote control terminal; full-authority fly-by-wire (FBB) flight control software; control augmentation system software; pilot interface unit software; and servo control software. It includes: a full-authority fly-by-wire flight control function controlled by a VMC; a FBB system where the VMC and PIU work collaboratively; an emergency backup control system controlled by the PIU; a control augmentation system involving the functions of the VMC and mechanical transmission devices; a control augmentation system where the VMC, PIU, and mechanical transmission devices work collaboratively; an emergency backup augmentation system where the PIU and mechanical transmission devices work together; and a mechanical backup mode controlled purely by mechanical means and cables. It enables dynamic reconfiguration of the functions of each node based on the distributed flight control system, employs a distributed redundancy design, and enhances the safety of the flight control system.

Description

Technical Field

[0001] This invention belongs to the field of flight control systems, and specifically relates to a flight control method and apparatus for a distributed flight control system. Background Technology

[0002] The flight control system is a safety-critical airborne system. Its functions not only affect the flight quality of the aircraft, but also seriously affect the safety of the aircraft.

[0003] In existing flight control system architectures, there are generally two modes: centralized processing and distributed processing. Centralized processing typically uses the 659 bus for signal acquisition, with the main flight control computer handling redundancy management, control law calculations, and sending control commands to remote control terminals to manipulate control surfaces. Because the flight control computer handles signal acquisition, command calculation, and control command output in centralized processing, it features a simple architecture and high computational efficiency. However, the security of a centralized flight control system largely depends on the security of the main flight control computer; if the flight control computer malfunctions or degrades, the security of the entire system will decrease.

[0004] Distributed flight control systems represent a novel architectural paradigm that has seen widespread application in research projects. Typically, a distributed flight control system uses a 1394 bus to connect the nodes in the flight control network, enabling communication between them. The Aircraft Management Computer (VMC) node manages the entire flight control network, while other nodes handle data acquisition and computation for their respective functions. Compared to centralized systems, distributed systems employ redundant designs in their modules, resulting in a more complex structure. The functionality of any single node can be shared among other nodes. Therefore, distributed flight control systems offer higher security than centralized systems; even if the VMC node fails, the entire flight control system will not be paralyzed.

[0005] However, limited by processor computing power, existing distributed systems suffer from drawbacks such as single-function software on each node and weak reconfiguration capabilities. For example, in the current distributed flight control architecture, the same application software program is often deployed on the four aircraft management computers. Once a software failure occurs, it can easily lead to common-mode problems, causing system failure and affecting flight safety. Secondly, in the existing command selection logic, the VMC still holds the highest authority and dominates the flight control system. Even if the VMC has been degraded to single redundancy, the input signals of the remote control terminal (ART) still prioritize the VMC's commands, ignoring the output commands of other nodes (such as the pilot interface unit PIU). Since there are no other channels for comparison and monitoring, the control commands calculated by the VMC have certain security risks.

[0006] In conclusion, although distributed flight control systems offer improved safety compared to centralized systems, there is still room for improvement due to the unreasonable allocation of some functions. Summary of the Invention

[0007] This invention proposes a flight control method and device for a distributed flight control system to alleviate the problems of single node function and weak risk resistance in existing distributed flight control systems.

[0008] This invention proposes a flight control method for a distributed flight control system, the distributed flight control system comprising: a quadruple-redundant remote control terminal, an aircraft management computer (VMC), and a pilot interface unit (PIU); the method comprises:

[0009] Step 1: In each mission cycle of the flight control system, determine the effective status of the quadruple redundancy remote control terminal; if all are effective, proceed to Step 2; if some are ineffective, proceed to Step 3.

[0010] Step 2: If the quadruple-redundant aircraft management computer fails, and the number of valid pilot interface units is greater than the number of valid aircraft management computers, then determine the VMC weighting coefficient and PIU weighting coefficient based on the number of valid pilot interface units and the number of valid aircraft management computers; generate flight control commands based on the VMC weighting coefficient and PIU weighting coefficient, as well as the commands obtained from the VMC and PIU for full authority control law calculation.

[0011] Step 3: If the quadruple-redundant aircraft management computer fails, determine the VMC weighting coefficient and PIU weighting coefficient based on the effective number of pilot interface units and the effective number of aircraft management computers; generate computer control commands based on the VMC weighting coefficient, PIU weighting coefficient, and the commands obtained from the control law calculations of the VMC and PIU; determine the computer weighting coefficient and mechanical device weighting coefficient based on the effective number of remote control terminals; generate flight control commands based on the computer weighting coefficient, mechanical device weighting coefficient, computer control commands, and mechanical control commands.

[0012] Optionally, the VMC weighting coefficient and PIU weighting coefficient are determined based on the effective number of pilot interface units and the effective number of aircraft management computers, including:

[0013] If (PIU significant number – VMC significant number) = 1, the VMC weighting coefficient is the first value, the PIU weighting coefficient is the second value, the first value is greater than the second value, and the sum of the first value and the second value is 1;

[0014] If (PIU significant number – VMC significant number) = 2, the VMC weighting coefficient is 0.5, and the PIU weighting coefficient is 0.5.

[0015] If (PIU significant number – VMC significant number) = 3, the VMC weighting coefficient is the third value, the PIU weighting coefficient is the fourth value, the third value is less than the fourth value, and the sum of the third and fourth values ​​is 1.

[0016] Optionally, the flight control command in step 2 = control surface position command calculated by VMC * VMC weighting coefficient + control surface position command calculated by PIU * PIU weighting coefficient.

[0017] Optionally, based on the effective number of remote control terminals, determine the computer weighting coefficient and the mechanical device weighting coefficient, including:

[0018] When the number of effective remote control terminals is 3, the computer weighting coefficient is the fifth value, and the mechanical device weighting coefficient is the sixth value; the fifth value is greater than the sixth value, and the sum of the fifth and sixth values ​​is 1.

[0019] When the effective number of remote control terminals is 2, the weighting factor for computers is 50%, and the weighting factor for mechanical devices is 50%;

[0020] When the effective number of remote control terminals is 1, the computer weighting coefficient is the seventh value, the mechanical device weighting coefficient is the eighth value, the eighth value is greater than the seventh value, and the sum of the eighth value and the seventh value is 1.

[0021] Optionally, the flight control command in step 3 = computer control command * computer weighting coefficient + mechanical control command * mechanical device weighting coefficient.

[0022] Optionally, if the effective state of the quadruple-redundant remote control terminal is completely ineffective, the method further includes:

[0023] Confirm that the flight control system is in mechanical backup mode;

[0024] When the flight control system is in mechanical backup mode, flight control commands are generated by the steel cable and tension regulator.

[0025] Optionally, if the effective state of the quadruple-redundant remote control terminal is not completely failed, but the quadruple-redundant aircraft management computer is completely failed, the method further includes:

[0026] If all four redundant pilot interface units fail, the flight control system is determined to be in mechanical backup mode; otherwise, computer control commands are generated based on the instructions obtained from the emergency backup control law calculation by the PIU.

[0027] In another aspect, the present invention provides a flight control device for a distributed flight control system, the distributed flight control system comprising: a quadruple-redundant remote control terminal, an aircraft management computer (VMC), and a pilot interface unit (PIU); the device comprising:

[0028] The effective judgment module is used to determine the effective status of the quadruple redundancy remote control terminal in each mission cycle of the flight control system.

[0029] The first instruction generation module is used to determine the VMC weighting coefficient and PIU weighting coefficient when the quadruple-redundant remote control terminal is in a fully active state, if the quadruple-redundant aircraft management computer fails and the number of active pilot interface units is greater than the number of active aircraft management computers, based on the number of active pilot interface units and the number of active aircraft management computers; and to generate flight control instructions based on the VMC weighting coefficient, PIU weighting coefficient, instructions obtained from the VMC's full authority control law calculation, and instructions obtained from the PIU's full authority control law calculation.

[0030] The second instruction generation module is used to determine the VMC weighting coefficient and PIU weighting coefficient when the effective state of the quadredundant remote control terminal is partially failed, and if the quadredundant aircraft management computer is partially failed. Based on the effective number of pilot interface units and the effective number of aircraft management computers, the module generates computer control instructions. Based on the VMC weighting coefficient and PIU weighting coefficient, as well as the instructions obtained from the control law calculations of the VMC and PIU, the module determines the computer weighting coefficient and mechanical device weighting coefficient. Based on the computer weighting coefficient and mechanical device weighting coefficient, the module generates flight control instructions.

[0031] Optionally, the first instruction generation module and the second instruction generation module are specifically used for:

[0032] If (PIU significant number – VMC significant number) = 1, the VMC weighting coefficient is the first value, the PIU weighting coefficient is the second value, the first value is greater than the second value, and the sum of the first value and the second value is 1;

[0033] If (PIU significant number – VMC significant number) = 2, the VMC weighting coefficient is 0.5, and the PIU weighting coefficient is 0.5.

[0034] If (PIU significant number – VMC significant number) = 3, the VMC weighting coefficient is the third value, the PIU weighting coefficient is the fourth value, the third value is less than the fourth value, and the sum of the third value and the fourth value is 1.

[0035] Optionally, the first instruction generation module is specifically used to: calculate flight control instructions using the following formula;

[0036] Flight control command = Control surface position command calculated by VMC * VMC weighting coefficient + Control surface position command calculated by PIU * PIU weighting coefficient.

[0037] This invention provides a flight control method and apparatus for a distributed flight control system, which has the following technical features:

[0038] (1) By deploying two sets of software, fly-by-wire flight control and control stabilization, on VMC and PIU, the flight control system can dynamically switch between fly-by-wire and stabilization functions, reducing the probability of common-mode failure caused by software problems;

[0039] (2) By dynamically allocating control law calculation permissions to distributed network nodes such as VMC and PIU, the stability of the system is enhanced, and single points of failure caused by hardware problems are effectively avoided.

[0040] (3) Based on the status of flight control network nodes such as VMC, PIU, and ART, dynamic switching between full-authority fly-by-wire flight control status, control stabilization status, and mechanical backup status can be realized, thereby maximizing flight quality while ensuring flight safety. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the architecture of the distributed flight control system provided by the present invention;

[0042] Figure 2 This is a flowchart illustrating the flight control method of the distributed flight control system provided by the present invention;

[0043] Figure 3 This is a functional schematic diagram of the distributed flight control system provided by the present invention. Detailed Implementation

[0044] The flight control method and apparatus of the distributed flight control system provided by the present invention will be explained and described below with reference to the accompanying drawings.

[0045] This invention provides a distributed flight control system that supports dynamic reconfiguration, comprising two parts: system architecture design and software solution design.

[0046] like Figure 1 and Figure 3As shown, the system architecture is designed as follows: The distributed flight control system mainly includes the following nodes: Aircraft Management Computer (VMC), Pilot Interface Unit (PIU), and Remote Control Terminal (ART). The nodes are connected via a 1394 bus, and communicate with each other by sending 1394 asynchronous stream data packets. The Aircraft Management Computer is the central processing node, while the Pilot Interface Unit and the ART are remote nodes. The central node can periodically send STOF packets to various remote nodes, and can also communicate with specific remote nodes by sending asynchronous stream packets.

[0047] The software solution is designed as follows: In the distributed flight control system, two software sets need to be deployed within the VMC: fly-by-wire flight control software and control augmentation software. The task scheduling between the software is based on the feedback results from the ART. For example, when the ART sends its status to the VMC as quadruple redundancy, the VMC schedules the fly-by-wire flight control software and sends the calculated output commands to the ART. When the ART reports a triple redundancy status, the VMC schedules the control augmentation software with 80% command authority. Similarly, when the asynchronous stream packet refresh flag sent by the ART to the VMC is not updated, the VMC determines that all four ARTs have failed, the system switches to mechanical backup mode, and the VMC reports the current status to the pilot.

[0048] Similar to VMC, PIU also requires the deployment of two software sets: emergency backup fly-by-wire flight control software and emergency backup control and stabilization software. PIU software scheduling is executed based on VMC commands and ART status. For example, when ART degrades, VMC sends the ART status to PIU via STOF packets, at which point PIU switches from emergency backup mode to emergency backup control and stabilization software.

[0049] Compared to VMC and PIU, ART directly participates in the control of the aircraft's control surfaces, requiring faster response times and shorter execution cycles, typically 1ms or 3ms. Therefore, only one control surface control program is deployed on the ART, but it simultaneously receives output commands from both VMC and PIU, determining the proportion of input signals based on the states of VMC and PIU. For example, when PIU is 4x redundancy and VMC is 3x redundancy, PIU commands account for 20% and VMC commands account for 80% of the ART signal input. The specific calculation is as follows: ART input signal = VMC control command * 0.8 + PIU control command * 0.2. Similarly, when both VMC and PIU fail, i.e., the asynchronous stream packet heartbeat words sent by VMC and PIU are not updated, the ART loses control of the control surfaces, and the system switches to mechanical backup mode.

[0050] Figure 2 This is a flowchart illustrating the flight control method of the distributed flight control system provided by the present invention, as shown below. Figure 2As shown, the specific work steps are as follows:

[0051] Step 1: After entering the periodic task, first check the ART status. If all are valid, proceed to Step 2; if all are invalid, proceed to Step 8; if some are invalid, proceed to Step 9.

[0052] Step 2: Determine the VMC status; if part of the VMC is invalid, proceed to Step 3; if all VMCs are valid, proceed to Step 4; if all VMCs are invalid, proceed to Step 6.

[0053] At this time, the system is considered to be in full authority fly-by-wire control state. In this state, the full authority control law command is calculated by VMC or PIU, and the ART completes the manipulation of the control law command to the control surface position. The mechanical device does not participate in the control surface control.

[0054] Step 3: At this point, it is necessary to determine the fault status of the PIU; if the number of valid computers in the PIU is less than or equal to the number of valid computers in the VMC, proceed to step 4; if the number of valid computers in the PIU is greater than the number of valid computers in the VMC, proceed to step 5.

[0055] Step 4: The VMC completes the calculation of the full authority control law, and the ART receives instructions from the VMC to complete the control surface manipulation;

[0056] Step 5: The ART simultaneously receives full authority control law instructions from both the VMC and PIU, and weights the received instructions. The weighting algorithm is as follows:

[0057] If (PIU effective number – VMC effective number) = 1, then the ART input signal = VMC calculated control surface command * 0.8 + PIU calculated control surface command * 0.2;

[0058] If (PIU effective number – VMC effective number) = 2, then the ART input signal = VMC calculated control surface command * 0.5 + PIU calculated control surface command * 0.5;

[0059] If (PIU effective number – VMC effective number) = 3, then the ART input signal = VMC calculated control surface command * 0.2 + PIU calculated control surface command * 0.8.

[0060] Step 6: The system needs to determine the PIU status; if at least one PIU is valid, proceed to Step 7; if all PIUs are invalid, proceed to Step 8.

[0061] Step 7: The PIU completes the calculation of the emergency backup control law, and the ART only receives instructions from the PIU to complete the control surface manipulation;

[0062] Step 8: At this point, the system is considered to be in mechanical backup mode. ART does not have the authority to manipulate the control surfaces, and mechanical devices such as steel cables and tension regulators are used to control the control surfaces.

[0063] Step 9: At this point, the system is considered to be in a control augmentation state. Further calculation of the augmentation control command is needed based on the states of the VMC and PIU, specifically including the following nine scenarios:

[0064] The first method: When one ART fails, if all VMCs are active or the number of active computers in the VMC is greater than or equal to the number of active computers in the PIU, then the VMC will complete the calculation of the stability augmentation command. The stability augmentation command accounts for 80% of the control surface authority, and the mechanical device accounts for 20% of the control surface authority.

[0065] The second method: When one ART fails, if the VMC is partially effective and the number of effective computers in the VMC is less than the number of effective computers in the PIU, the control stabilization command is calculated jointly by the VMC and PIU. The calculation method for the proportion of control stabilization commands in the VMC and PIU is the same as the weighting method described in step 5. In the allocation of authority for control surface commands, stabilization commands account for 80% and mechanical controls account for 20%.

[0066] The third scenario: When two ARTs fail, if the VMC is fully active or the number of active computers in the VMC is greater than the number of active computers in the PIU, then the VMC will complete the calculation of the stability augmentation command. The stability augmentation command accounts for 50% of the control surface authority, and the mechanical device accounts for 50% of the control surface authority.

[0067] The fourth type: When two ARTs fail, if the VMC is fully active or the number of active computers in the VMC is less than the number of active computers in the PIU, the control stabilization command is calculated jointly by the VMC and PIU. The calculation method for the proportion of VMC and PIU commands is the same as the weighting method described in step 5. In the allocation of authority for control surface commands, stabilization commands account for 50% and mechanical controls account for 50%.

[0068] Fifth: When three ARTs fail, if all VMCs are active or the number of active VMCs is greater than the number of active PIUs, then the VMCs will be responsible for calculating the stability augmentation commands. The stability augmentation commands account for 20% of the control surface authority, and the mechanical devices account for 80% of the control surface authority.

[0069] The sixth method: When three ARTs fail, if all VMCs are active or the number of active VMC computers is less than the number of active PIU computers, the control stabilization command is calculated jointly by VMC and PIU. The calculation method for the proportion of VMC and PIU commands is the same as the weighting method described in step 5. In the allocation of authority for control surface commands, stabilization commands account for 20% and mechanical controls account for 80%.

[0070] The seventh scenario: When one ART fails and all VMCs fail, it is necessary to determine the PIU status. If all PIUs fail, proceed to step 8; if at least one PIU is valid, the PIU will complete the calculation of the stability augmentation command. In the allocation of authority for control surface commands, stability augmentation commands account for 80%, and mechanical control accounts for 20%.

[0071] Eighth scenario: When two ARTs fail and the VMC fails completely, it is necessary to determine the PIU status. If all PIUs fail, proceed to step 8; if at least one PIU is valid, the PIU will complete the calculation of the stability augmentation command. In the allocation of authority for control surface commands, stability augmentation commands account for 50%, and mechanical control accounts for 50%.

[0072] Ninth: When three ARTs fail and all VMCs fail, the PIU status needs to be determined. If all PIUs fail, proceed to step 8; if at least one PIU is valid, the PIU will complete the calculation of the stability augmentation command. In the allocation of authority for control surface commands, stability augmentation commands account for 20%, and mechanical control accounts for 80%.

Claims

1. A flight control method for a distributed flight control system, characterized in that, The distributed flight control system includes: a quadruple-redundant remote control terminal, an aircraft management computer (VMC), and a pilot interface unit (PIU); the method includes: Step 1: In each mission cycle of the flight control system, determine the effective status of the quadruple redundancy remote control terminal; if all are effective, proceed to Step 2; if some are ineffective, proceed to Step 3. Step 2: If the quadruple-redundant aircraft management computer fails, and the number of valid pilot interface units is greater than the number of valid aircraft management computers, then determine the VMC weighting coefficient and PIU weighting coefficient based on the number of valid pilot interface units and the number of valid aircraft management computers; generate flight control commands based on the VMC weighting coefficient and PIU weighting coefficient, as well as the commands obtained from the VMC and PIU for full authority control law calculation. Step 3: If the quadruple-redundant aircraft management computer fails, determine the VMC weighting coefficient and PIU weighting coefficient based on the effective number of pilot interface units and the effective number of aircraft management computers; generate computer control commands based on the VMC weighting coefficient, PIU weighting coefficient, and the commands obtained from the control law calculations of the VMC and PIU; determine the computer weighting coefficient and mechanical device weighting coefficient based on the effective number of remote control terminals; generate flight control commands based on the computer weighting coefficient, mechanical device weighting coefficient, computer control commands, and mechanical control commands. Based on the effective number of pilot interface units and the effective number of aircraft management computers, determine the VMC weighting coefficient and PIU weighting coefficient, including: If (PIU significant number – VMC significant number) = 1, the VMC weighting coefficient is the first value, the PIU weighting coefficient is the second value, the first value is greater than the second value, and the sum of the first value and the second value is 1; If (PIU significant number – VMC significant number) = 2, the VMC weighting coefficient is 0.5, and the PIU weighting coefficient is 0.

5. If (PIU significant number – VMC significant number) = 3, the VMC weighting coefficient is the third value, the PIU weighting coefficient is the fourth value, the third value is less than the fourth value, and the sum of the third value and the fourth value is 1; The flight control command in step 2 = control surface position command calculated by VMC * VMC weighting coefficient + control surface position command calculated by PIU * PIU weighting coefficient; Based on the effective number of remote control terminals, determine the computer weighting coefficient and the mechanical device weighting coefficient, including: When the number of valid remote control terminals is 3, the computer weighting coefficient is the fifth value, and the mechanical device weighting coefficient is the sixth value; the fifth value is greater than the sixth value, and the sum of the fifth and sixth values ​​is 1. When the number of effective remote control terminals is 2, the weighting factor for computers is 50%, and the weighting factor for mechanical devices is 50%; When the number of valid remote control terminals is 1, the computer weighting coefficient is the seventh value, the mechanical device weighting coefficient is the eighth value, the eighth value is greater than the seventh value, and the sum of the eighth value and the seventh value is 1. The flight control command in step 3 = computer control command * computer weighting coefficient + mechanical control command * mechanical device weighting coefficient.

2. The method according to claim 1, characterized in that, If the effective state of the quadruple-redundant remote control terminal is completely ineffective, the method further includes: Confirm that the flight control system is in mechanical backup mode; When the flight control system is in mechanical backup mode, flight control commands are generated by the steel cable and tension regulator.

3. The method according to claim 1, characterized in that, If the effective state of the quadruple-redundant remote control terminal is not completely failed, but the quadruple-redundant aircraft management computer is completely failed, the method further includes: If all four redundant pilot interface units fail, the flight control system is determined to be in mechanical backup mode; otherwise, computer control commands are generated based on the instructions obtained from the emergency backup control law calculation by the PIU.

4. A flight control device for a distributed flight control system, characterized in that, The distributed flight control system includes: a quadruple-redundant remote control terminal, an aircraft management computer (VMC), and a pilot interface unit (PIU); the device includes: The effective judgment module is used to determine the effective status of the quadruple redundancy remote control terminal in each mission cycle of the flight control system. The first instruction generation module is used to determine the VMC weighting coefficient and PIU weighting coefficient when the quadruple-redundant remote control terminal is in a fully active state, if the quadruple-redundant aircraft management computer fails and the number of active pilot interface units is greater than the number of active aircraft management computers, based on the number of active pilot interface units and the number of active aircraft management computers; and to generate flight control instructions based on the VMC weighting coefficient, PIU weighting coefficient, instructions obtained from the VMC's full authority control law calculation, and instructions obtained from the PIU's full authority control law calculation. The second instruction generation module is used to determine the VMC weighting coefficient and PIU weighting coefficient when the effective state of the quadruple-redundant remote control terminal is partially failed, and if the quadruple-redundant aircraft management computer is partially failed. Based on the effective number of pilot interface units and the effective number of aircraft management computers, the module generates computer control instructions. Based on the VMC weighting coefficient and PIU weighting coefficient, and the instructions obtained from the control law calculations of the VMC and PIU, it determines the computer weighting coefficient and mechanical device weighting coefficient. Based on the computer weighting coefficient and mechanical device weighting coefficient, and the computer control instructions and mechanical control instructions, it generates flight control instructions. The first instruction generation module and the second instruction generation module are specifically used for: If (PIU significant number – VMC significant number) = 1, the VMC weighting coefficient is the first value, the PIU weighting coefficient is the second value, the first value is greater than the second value, and the sum of the first value and the second value is 1; If (PIU significant number – VMC significant number) = 2, the VMC weighting coefficient is 0.5, and the PIU weighting coefficient is 0.

5. If (PIU significant number – VMC significant number) = 3, the VMC weighting coefficient is the third value, the PIU weighting coefficient is the fourth value, the third value is less than the fourth value, and the sum of the third value and the fourth value is 1; The first instruction generation module is specifically used to: calculate flight control instructions using the following formula; Flight control command = Control surface position command calculated by VMC * VMC weighting coefficient + Control surface position command calculated by PIU * PIU weighting coefficient; The second instruction generation module is specifically used for: when the number of valid remote control terminals is 3, the computer weighting coefficient is the fifth value, and the mechanical device weighting coefficient is the sixth value; the fifth value is greater than the sixth value, and the sum of the fifth and sixth values ​​is 1; when the number of valid remote control terminals is 2, the computer weighting coefficient is 50%, and the mechanical device weighting coefficient is 50%; when the number of valid remote control terminals is 1, the computer weighting coefficient is the seventh value, and the mechanical device weighting coefficient is the eighth value, the eighth value is greater than the seventh value, and the sum of the eighth and seventh values ​​is 1; The second instruction generation module is specifically used to calculate flight control instructions using the following formula; Flight control commands = Computer control commands * Computer weighting coefficient + Mechanical control commands * Mechanical device weighting coefficient.

Images