Airplane rudder control device and airplane rudder control method
By calculating the rudder deflection limit in real time and using flight parameters and aerodynamic state detection, the problem of excessive vertical tail load was solved, achieving the effect of reducing vertical tail load and maintaining yaw control capability under extreme maneuvers, and simplifying the system structure.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- COMMERCIAL AIRCRAFT CORP OF CHINA LTD
- Filing Date
- 2026-06-12
- Publication Date
- 2026-07-24
AI Technical Summary
In existing technologies, pilot foot pedal operation during aircraft flight may cause the vertical tail load to exceed the limit, leading to vertical tail breakage. Furthermore, using sideslip angle sensors as input sources will change the original heading control scheme and increase system complexity.
By detecting the aircraft's flight parameters and aerodynamic status, the rudder deflection limit is calculated in real time. The final value of the rudder command is calculated using the input from the rudder control unit, which drives the rudder movement, avoids excessive vertical tail load, simplifies the structure, and maintains the original heading control scheme.
It effectively reduced the vertical tail load of the aircraft under extreme maneuvers, avoiding structural damage, while maintaining the aircraft's yaw control capability and simplifying the system structure.
Smart Images
Figure CN122443672A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an aircraft rudder control device and an aircraft rudder control method. Background Technology
[0002] The vertical tail of a civil aircraft typically includes a rudder, and the movement of the rudder is usually controlled by pedals.
[0003] During flight, pilots sometimes repeatedly operate the pedals to deflect the rudder. This may cause the vertical tail load to exceed the limit, resulting in the vertical tail breaking off.
[0004] In response to the above situation, one previous solution was to directly control and limit sideslip using foot pedals, thereby reducing the load on the vertical tail.
[0005] However, the above solutions require an additional sideslip angle signal as an input source. Therefore, using a sideslip angle sensor as the sideslip signal source would pose challenges to the system equipment layout and could easily alter the aircraft's original heading control scheme. Summary of the Invention
[0006] The present invention was made in view of the above-mentioned problems, and its purpose is to provide an aircraft rudder control device and an aircraft rudder control method, which helps to reduce the vertical tail load of the aircraft under extreme maneuvers with a simple structure and avoid damage to the aircraft structure.
[0007] To achieve the above objectives, the present invention provides an aircraft rudder control device, comprising: a flight parameter detection unit for detecting the flight parameters of the aircraft; an aerodynamic state detection unit for detecting the aerodynamic state of the aircraft; a rudder control unit for pilot operation to input yaw demand information; a control unit for obtaining a final rudder command value by comparing an initial rudder command value with a rudder deflection limit value, wherein the initial rudder command value is calculated by the control unit based on the yaw demand information, and the rudder deflection limit value is calculated by the control unit based on an estimated vertical tail load value and the estimated vertical tail load, based on the flight parameters and the aerodynamic state; and a rudder drive unit for driving the rudder to move according to the final rudder command value.
[0008] According to the aircraft rudder control device of the present invention, the rudder deflection limit value calculated based on the aircraft's flight parameters and aerodynamic state is used to limit the initial value of the rudder command calculated based on the input of the rudder control unit, thereby obtaining the final value of the rudder command and driving the rudder accordingly. Therefore, unlike the case of setting a sideslip angle sensor, it helps to simplify the structure without changing the original heading control scheme of the aircraft. Furthermore, it helps to reduce the vertical tail load of the aircraft under extreme control and avoid damage to the aircraft structure.
[0009] Furthermore, in the aircraft rudder control device of the present invention, it is preferable that the control unit calculates the rudder deflection limit value in real time.
[0010] According to the aircraft rudder control device of the present invention, the control unit calculates the rudder deflection limit value in real time. That is, the rudder deflection limit value is dynamically changing. Therefore, it helps to reliably reduce the vertical tail load of the aircraft under extreme control and easily ensures the aircraft's yaw control capability. In other words, even if the maximum rudder deflection is limited to a small value at a certain point in time due to the estimated vertical tail load exceeding the limit, the limitation on the maximum rudder deflection can be immediately reduced when the subsequently estimated vertical tail load decreases, thereby increasing the aircraft's yaw control capability.
[0011] Furthermore, in the aircraft rudder control device of the present invention, the flight parameters preferably include one or more of the following: three-axis overload, aircraft attitude, and motion angular velocity information.
[0012] The aircraft rudder control device according to the present invention, especially when the flight parameters include multiple information such as triaxial overload, aircraft attitude and motion angular velocity, helps to improve the estimation accuracy of vertical tail load, thereby making it easier to reduce the vertical tail load of the aircraft under extreme control while ensuring the aircraft's yaw control capability.
[0013] Furthermore, in the aircraft rudder control device of the present invention, the aerodynamic state preferably includes airspeed.
[0014] Furthermore, to achieve the above objectives, the present invention provides an aircraft rudder control method, comprising: detecting the aircraft's flight parameters and aerodynamic state to obtain yaw demand information input from a rudder control unit operated by the pilot; obtaining a final rudder command value by comparing an initial rudder command value with a rudder deflection limit value, wherein the initial rudder command value is calculated based on the yaw demand information, and the rudder deflection limit value is calculated based on an estimated vertical tail load based on the flight parameters and aerodynamic state, and then based on the vertical tail load limit value and the estimated vertical tail load; and outputting the final rudder command value to a rudder drive unit to drive the rudder movement.
[0015] According to the aircraft rudder control method of the present invention, the rudder deflection limit value calculated based on the aircraft's flight parameters and aerodynamic state is used to limit the initial value of the rudder command calculated based on the input of the rudder control unit, thereby obtaining the final value of the rudder command and driving the rudder accordingly. Therefore, unlike the case of setting a sideslip angle sensor, it helps to simplify the structure without changing the original heading control scheme of the aircraft. Furthermore, it helps to reduce the vertical tail load of the aircraft under extreme control and avoid damage to the aircraft structure.
[0016] Furthermore, in the aircraft rudder control method of the present invention, it is preferable to calculate the rudder deflection limit value in real time.
[0017] According to the aircraft rudder control method of the present invention, the rudder deflection limit value is calculated in real time, that is, the rudder deflection limit value is dynamically changing. Therefore, it helps to reliably reduce the vertical tail load of the aircraft under extreme maneuvers and easily ensures the aircraft's yaw control capability.
[0018] Furthermore, in the aircraft rudder control method of the present invention, the flight parameters preferably include one or more of the following: three-axis overload, aircraft attitude, and motion angular velocity information.
[0019] The aircraft rudder control method of the present invention, especially when the flight parameters include multiple information such as three-axis overload, aircraft attitude and motion angular velocity, helps to improve the estimation accuracy of vertical tail load, thereby making it easier to reduce the vertical tail load of the aircraft under extreme control while ensuring the aircraft's yaw control capability.
[0020] Furthermore, in the aircraft rudder control method of the present invention, the aerodynamic state preferably includes airspeed. Attached Figure Description
[0021] Figure 1 This is a schematic block diagram illustrating the structure of an aircraft rudder control device according to an embodiment of the present invention.
[0022] Figure 2 This is a flowchart illustrating an embodiment of the aircraft rudder control method of the present invention.
[0023] Symbol Explanation
[0024] 1. Aircraft rudder control device
[0025] 10 Flight Parameter Monitoring Department
[0026] 20. Pneumatic Condition Monitoring Department
[0027] 30. Rudder control unit
[0028] 40 Control Department
[0029] 50. Rudder drive unit
[0030] 60 rudder Detailed Implementation
[0031] Below, in conjunction with Figure 1 and Figure 2 The present invention describes the aircraft rudder control device and aircraft rudder control method according to embodiments of the present invention.
[0032] Structure of aircraft rudder control device
[0033] like Figure 1 As shown, the aircraft rudder control device 1 according to an embodiment of the present invention includes: a flight parameter detection unit 10 for detecting the flight parameters of the aircraft; an aerodynamic state detection unit 20 for detecting the aerodynamic state of the aircraft; a rudder control unit 30 for the pilot to operate to input yaw demand information; a control unit 40 for obtaining a final rudder command value by comparing an initial rudder command value with a rudder deflection limit value, wherein the initial rudder command value is calculated by the control unit 40 based on the yaw demand information, and the rudder deflection limit value is calculated by the control unit 40 based on the vertical tail load estimated according to the flight parameters and aerodynamic state, and based on the vertical tail load limit value and the estimated vertical tail load; and a rudder drive unit 50 for driving the rudder 60 to move according to the final rudder command value.
[0034] Here, the flight parameter detection unit 10 is, for example, composed of an inertial navigation sensor, which collects at least one of the three-axis overload, aircraft attitude and motion angular velocity information as flight parameters and outputs it to the control unit 40.
[0035] In addition, the aerodynamic state detection unit 20 is, for example, composed of an atmospheric measurement device, which measures the airspeed as an aerodynamic state and outputs it to the control unit 40.
[0036] In addition, the rudder control unit 30 is, for example, composed of foot pedals, which collects the driver's action commands and outputs them to the control unit 40.
[0037] Furthermore, the control unit 40, for example, is composed of a flight control computer. It receives flight parameters detected by the flight parameter detection unit 10, aerodynamic conditions detected by the aerodynamic condition detection unit 20, and input yaw demand information input by the rudder control unit 30. Based on this information, it performs processing such as calculating rudder deflection limits. Moreover, the control unit 40 calculates the rudder deflection limit in real time; this limit is a function of aircraft attitude, overload, angular velocity, and airspeed, and is not a fixed value.
[0038] Specifically, the control unit 40 uses a vertical tail load mitigation estimation model to monitor the aircraft's vertical tail load in real time and automatically during flight, based on flight parameters such as lateral overload, vacuum speed, and yaw rate. Once the vertical tail load estimated by the model exceeds a predetermined threshold, the control unit 40 dynamically limits the maximum rudder deflection, thereby limiting the vertical tail load (for example, if the initial rudder command value is greater than the rudder deflection limit value, the rudder deflection limit value is output as the final rudder command value). Conversely, when the vertical tail load estimated by the model is below the predetermined threshold, the control unit 40 removes the dynamic limitation on the maximum rudder deflection, ensuring the aircraft's directional control capability.
[0039] More specifically, the control unit 40 performs calculations and processing as follows, for example.
[0040] First, calculate VT according to the following formula (1). loadAOS .
[0041] (1)
[0042] In the above formula (1), VT loadAOS It is the vertical tail load of the aircraft; K load.beta These are fixed parameters, related to the aircraft's aerodynamic characteristics, and can be obtained from wind tunnel test data or theoretical calculations; AOS local_calculation It is the local sideslip of the vertical tail, which is calculated by the following formula 2.
[0043] (2)
[0044] In the above formula (2), AOS body_calculation This is the estimated sideslip angle for the entire aircraft, calculated using Formula 3 below; AOS local_correction It is the local sideslip angle correction value of the vertical tail, which is calculated by the following formula 4.
[0045] (3) (4) In the above formula (3), mass is the aircraft weight, which is measured, for example, by sensors such as fuel level sensors; n y It is lateral overload, for example, measured by sensors such as inertial navigation sensors; g is gravitational acceleration; C yrudder This is the lateral force coefficient of the rudder, which is related to the aircraft's aerodynamic characteristics and can be obtained from wind tunnel test data or theoretical calculations; δ rud This refers to the rudder deflection, the actual value of which is measured by sensors such as angle sensors or displacement sensors, and is used to correct the AOS (Automatic Stability). body_calculation Estimated sideslip angle for the entire aircraft; Q barIt is dynamic pressure, for example, measured by sensors such as atmospheric data sensors; S is the wing reference area, which is a fixed parameter, for example, obtained based on the aircraft's external shape and layout; C ybeta It is the aircraft aerodynamic side force coefficient, which is a fixed parameter related to the aircraft's aerodynamic characteristics and can be obtained from wind tunnel test data or theoretical calculations.
[0046] In the above formula (4), r body It is the yaw rate, which is measured by sensors such as inertial navigation sensors; L is the axial distance from the center of gravity to the 25% mean aerodynamic chord of the vertical tail, which is a fixed parameter, such as that obtained according to the aircraft's shape and layout; V is the vacuum speed, which is measured by sensors such as atmospheric data sensors.
[0047] Incidentally, based on the above formulas (1)-(4), the relationship between the vertical tail load and the rudder deflection of the aircraft can be determined, and a positive expression for the vertical tail load (rudder deflection is the independent variable) can be constructed. Of course, the above relationship can also be obtained through experiments, and a mapping table can be made. Then, the vertical tail load can be determined from the rudder deflection by searching, difference method, etc.
[0048] Next, the rudder deflection limit value is calculated according to the following formulas (5) and (6). Specifically, the upper limit δ of the dynamic rudder limit value is calculated according to the following formula (5). rud_uplimit The lower limit δ of the rudder dynamic limit is calculated according to the following formula (6). rud_dnlimit .
[0049] (5) (6) In the above formulas (5) and (6), f VTload ^(-1) is a fixed relationship, related to the aerodynamic characteristics of the aircraft, and can be theoretically calculated according to the above formulas (1)-(4). That is, the inverse function is derived by performing the inverse operation on the forward expression of the vertical tail load with the rudder deflection limit as the independent variable. Alternatively, it can be obtained from wind tunnel test data, and a mapping table is made. Then, the rudder deflection limit is determined from the vertical tail load by searching, difference method, etc.; VT rudder_uplimit VT is calculated using the following formula (7); rudder_dnlimit It is calculated by the following formula (8).
[0050] (7) (8) In the above formula (7), VT load_uplimit It is the expected vertical tail load limit value - upper limit, which is a fixed parameter and is determined according to the load design requirements; in the above formula (8), VT load_dnlimitIt is the expected lower limit of the vertical tail load, which is a fixed parameter and is determined according to the load design requirements.
[0051] Then, the calculated rudder skewness limit value is compared with the initial value of the rudder command calculated based on the yaw requirement information. If the initial value of the rudder command exceeds the limit, the rudder skewness limit value is output as the final value of the rudder command. On the other hand, if the initial value of the rudder command does not exceed the limit, the initial value of the rudder command is output as the final value of the rudder command.
[0052] Furthermore, the rudder drive unit 50 may be configured as a rudder actuator, for example. The rudder drive unit 50 receives the final value of the rudder command output by the control unit 40 and drives the rudder 60 to deflect, thereby realizing the movement of the control surface.
[0053] Aircraft rudder control methods
[0054] like Figure 2 As shown, the aircraft rudder control method of this invention includes: a first step S1, detecting the aircraft's flight parameters and aerodynamic state to obtain yaw demand information input from the rudder control unit operated by the pilot; a second step S2, obtaining the final rudder command value by comparing the initial rudder command value with the rudder deflection limit value, wherein the initial rudder command value is calculated based on the yaw demand information, and the rudder deflection limit value is calculated based on the vertical tail load estimated according to the flight parameters and aerodynamic state, and based on the vertical tail load limit value and the estimated vertical tail load; and a third step S3, outputting the final rudder value to the rudder drive unit to drive the rudder movement.
[0055] Simulation
[0056] To verify the effectiveness of the technical solution of this invention, a nonlinear six-degree-of-freedom simulation model of a certain type of civil aircraft (twin-engine turbofan passenger aircraft) was used for digital simulation verification.
[0057] Simulation conditions: Aircraft weight approximately 55 tons, steady climb scenario at 5,000m. Control input: Perform two full-foot pedal reciprocating maneuvers. Compare two scenarios: (1) Conventional control method without the technical solution of this invention; (2) Using the technical solution of this invention.
[0058] In conventional control methods, after receiving pedal commands, the rudder deflects at a maximum angle of 20°, exceeding the vertical tail structure's ultimate load limit and potentially causing damage. However, using the present invention, the control unit 40 automatically activates rudder deflection limiting before the vertical tail load reaches the structural ultimate load. Before the vertical tail reaches its maximum, the rudder deflection is actively limited to approximately 15°, keeping the peak vertical tail load within the structural ultimate load limit and ensuring structural safety. Simultaneously, although there is a slight delay in yaw control response, the aircraft can still achieve the expected course change, and the handling quality meets the requirements.
[0059] Main effects of this implementation method
[0060] The aircraft rudder control device 1 according to this embodiment has a simple overall structure, no special transmitters or equipment requirements, is easy to implement, has high reliability, and is suitable for upgrading the control scheme of existing aircraft.
[0061] Furthermore, the aircraft rudder control device 1 according to this embodiment can simultaneously meet the requirements for heading control and the requirements for protecting the vertical tail structure, thereby improving aircraft safety.
[0062] Furthermore, according to the aircraft rudder control device 1 of this embodiment, by using the vertical tail load mitigation estimation model to estimate the vertical tail load, it helps to improve the estimation accuracy of the vertical tail load, thereby making it easier to reduce the vertical tail load of the aircraft under extreme control while ensuring the aircraft's yaw control capability.
[0063] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above embodiments.
[0064] For example, in the above embodiment, the flight parameter detection unit 10 is composed of an inertial navigation sensor, but it is not limited to this and other sensors may also be provided to detect flight parameters.
[0065] Furthermore, in the above embodiments, the control unit 40 is configured as a flight control computer, but it is not limited to this and other specialized computers may also be used to configure the control unit 40.
[0066] Furthermore, in the above embodiments, there is no restriction on the order in which the aircraft's flight parameters, aerodynamic status, and yaw demand information are transmitted to the control unit 40; they can be transmitted sequentially or simultaneously.
Claims
1. An aircraft rudder control device, characterized in that, include: Flight parameter detection unit, which is used to detect the flight parameters of the aircraft; Aerodynamic condition detection unit, which is used to detect the aerodynamic condition of the aircraft; A rudder control unit, which is operated by the driver to input yaw requirement information; The control unit obtains the final rudder command value by comparing the initial rudder command value with the rudder deflection limit value. The initial rudder command value is calculated by the control unit based on the yaw requirement information, and the rudder deflection limit value is calculated by the control unit based on the estimated vertical tail load according to the flight parameters and aerodynamic state, and then based on the vertical tail load limit value and the estimated vertical tail load. A rudder drive unit that drives the rudder to move according to the final value of the rudder command.
2. The aircraft rudder control device as described in claim 1, characterized in that, The control unit calculates the rudder deflection limit value in real time.
3. The aircraft rudder control device as described in claim 1, characterized in that, The flight parameters include one or more of the following: triaxial overload, aircraft attitude, and angular velocity information.
4. The aircraft rudder control device as described in claim 1, characterized in that, The aerodynamic state includes airspeed.
5. A method for controlling an aircraft rudder, characterized in that, include: The aircraft's flight parameters and aerodynamic status are monitored, and yaw demand information is obtained from the rudder control unit operated by the pilot. The final rudder command value is obtained by comparing the initial rudder command value with the rudder deflection limit value. The initial rudder command value is calculated based on the yaw requirement information, and the rudder deflection limit value is calculated based on the estimated vertical tail load using the flight parameters and aerodynamic state, combined with the vertical tail load limit value and the estimated vertical tail load. The final value of the rudder is output to the rudder drive unit to drive the rudder movement.
6. The aircraft rudder control method as described in claim 5, characterized in that, The rudder deflection limit value is calculated in real time.
7. The aircraft rudder control method as described in claim 5, characterized in that, The flight parameters include one or more of the following: triaxial overload, aircraft attitude, and angular velocity information.
8. The aircraft rudder control method as described in claim 5, characterized in that, The aerodynamic state includes airspeed.