Lateral course asymmetric self-balancing method for large aircraft

Abstract

The invention belongs to the technical field of aircraft flight control system design, and particularly relates to a large aircraft transverse course asymmetric self-balancing method which comprises the steps that a rudder automatic balancing instruction storage module and an aileron automatic balancing instruction storage module are arranged; acquiring an automatic trimming working condition rudder and aileron instruction numerical value under a plurality of speed points in an aircraft speed range; establishing a linear interpolation table according to the command values of the rudder and the aileron under the automatic trimming working condition, performing linear interpolation calculation to obtain a rudder and aileron trimming command required at the current aircraft indicated airspeed, and controlling the rudder surface to deflect through the rudder and aileron trimming command; when the aircraft is in an artificial flight control mode, the lateral course asymmetry can be automatically trimmed, and the control burden of a pilot is relieved. According to the method, any hardware part does not need to be transformed, and related function modules of transverse heading automatic trimming can be added on the basis of an existing flight control law framework according to the method, so that the transformation cost is saved.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft flight control system design, and in particular relates to a method for self-balancing asymmetric lateral and tack directions of large aircraft. Background Art

[0002] Due to the level of manufacturing technology of large aircraft, it is impossible to achieve absolute symmetry of the aircraft's lateral and yaw structural shape, which will cause asymmetric lateral and yaw aerodynamic characteristics; in addition, under conditions such as fuel asymmetry, rudder sticking, wing damage, etc., the aircraft will also generate asymmetric torque, resulting in unexpected roll and yaw motions.

[0003] Modern fly-by-wire aircraft all have both automatic flight control and manual flight control modes. In the automatic flight control mode, certain operating modes of the automatic flight control system (such as heading / track keeping and horizontal navigation mode) can automatically balance lateral heading asymmetry.

[0004] However, in the manual flight control mode, most aircraft manual flight control systems cannot achieve automatic compensation for lateral asymmetry (such as Boeing B777 aircraft) because the lateral heading is not controlled by an integrator. The aircraft can only be balanced by the pilot's manual control of the control surface, which greatly increases the pilot's control burden.

[0005] Therefore, how to achieve automatic balancing of the aircraft is a problem that needs to be solved. Summary of the invention

[0006] The purpose of the present application is to provide a method for asymmetric lateral and tack self-balancing of a large aircraft, so as to solve the problem in the prior art that the pilot relies on manual control of the control surfaces to balance the aircraft, thereby increasing the operating burden of the pilot.

[0007] The technical solution of the present application is: a method for asymmetric self-balancing of a large aircraft in lateral and tack direction, comprising:

[0008] A rudder automatic trim command storage module and an aileron automatic trim command storage module are respectively provided in the automatic flight rudder command channel and the aileron command channel; when the automatic flight control subsystem is disconnected, the automatic flight rudder command and the aileron command are respectively the rudder automatic trim storage module command and the aileron automatic trim storage module command;

[0009] Obtaining the rudder automatic trim storage module instructions and the aileron automatic trim storage module instructions: identifying the automatic trim working condition and recording the current automatic trim instruction value; the automatic trim instruction value includes the automatic trim working condition rudder and aileron automatic flight instruction values ​​at multiple speed points within the aircraft speed range;

[0010] The rudder and aileron command values ​​of the automatic trim working condition at multiple speed points within the aircraft speed range are obtained; a linear interpolation table is established based on the rudder and aileron command values ​​of the automatic trim working condition, and the interpolation variable is the aircraft indicated airspeed; when the automatic flight control subsystem is disconnected, a linear interpolation calculation is performed based on the aircraft's current real-time aircraft indicated airspeed to obtain the rudder and aileron trim commands required at the current aircraft indicated airspeed, and the rudder and aileron trim commands are used to control the deflection of the control surface.

[0011] Preferably, the instruction storage process of the automatic balancing instruction storage module is: when the aircraft is in an automatic balancing condition, the current real-time indicated airspeed of the aircraft is obtained, and the current automatic balancing instruction value is recorded; when the aircraft is in a non-automatic balancing condition, the instruction value is not recorded, and the instruction value in the previous automatic balancing condition calculation cycle is maintained.

[0012] Preferably, the rudder automatic trim instruction storage module and the aileron automatic trim instruction storage module both store trim instructions for different aircraft speeds under trim conditions, and the trim instructions are combined with the selected aircraft speed points to form an interpolation table; the automatic trim instruction can be calculated according to the real-time speed of the aircraft through the interpolation table.

[0013] Preferably, the automatic trim working condition judgment logic of the aircraft is: after the aircraft takes off, when the radio altitude is greater than a certain altitude, the pilot will turn on the automatic flight control subsystem. When the lateral mode of the automatic flight control subsystem is working in the heading / track holding or horizontal navigation mode, and the wings are level, it is judged that the aircraft is in the automatic trim working condition at this time; otherwise, it is in the non-automatic trim working condition.

[0014] Preferably, the specific method for recording the current automatic trim command value is: when the aircraft is in the automatic trim working condition, speed points are selected at intervals of a certain value within the flight speed range of the aircraft, thereby selecting several speed points, and recording the aileron and rudder commands when the aircraft speed reaches each speed point respectively.

[0015] Preferably, the speed interval values ​​and speed points can be adaptively adjusted according to different aircraft.

[0016] Preferably, if the aircraft speed does not pass a certain speed point, the aileron and rudder instructions at the speed point that has not been passed are kept greater than the recorded values ​​of the rudder surface instructions at the next speed point of the speed point.

[0017] Preferably, each certain value interval specifically means that within the flight speed range, each interval of 50 km / h records the rudder automatic balancing storage module instructions and the aileron automatic balancing storage module instructions.

[0018] Preferably, after the aircraft speed reaches each speed point and remains for 2 seconds, the current rudder automatic trim instruction and aileron automatic trim instruction are recorded and stored in the rudder automatic trim instruction storage module and the aileron automatic trim instruction storage module respectively.

[0019] Preferably, under automatic flight control, the rudder and aileron instructions generated by the automatic flight control subsystem will be superimposed with the instructions in the manual flight control subsystem to generate the final rudder instructions; the superimposed instructions include automatic flight rudder instructions, manual flight rudder instructions, manual flight aileron instructions and automatic flight aileron instructions.

[0020] The large aircraft lateral and tack asymmetric self-balancing method of the present application enables the aircraft to automatically balance the lateral and tack asymmetry when in manual flight control mode, thereby reducing the pilot's control burden. The method does not require modification of any hardware part, and can be used to add lateral and tack automatic balancing related function modules based on the existing flight control law architecture, thereby saving modification costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solution provided by the present application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present application.

[0022] Figure 1 This is a schematic diagram of the overall process of this application;

[0023] Figure 2 This is a schematic diagram of the composition of the flight control system of a modern large aircraft for this application;

[0024] Figure 3 Add the schematic diagram of the automatic trim rudder and aileron command storage module to the basis of this application;

[0025] Figure 4 This is a logical diagram of the automatic balancing condition identification judgment for this application. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] A method for self-balancing asymmetric lateral heading of a large aircraft, such as Figure 1 As shown, the following steps are included:

[0028] Step S100, the flight control system of modern large aircraft is usually composed of an automatic flight control subsystem and a manual flight control subsystem. Under automatic flight control, the rudder and aileron instructions generated by the automatic flight control subsystem will be superimposed with the instructions in the manual flight control subsystem to generate the final rudder instructions. The superimposed instructions include automatic flight rudder instructions, manual flight rudder instructions, manual flight aileron instructions and automatic flight aileron instructions, such as Figure 2 .

[0029] In most aircraft manual flight control modes, the lateral heading control law does not use integral control and cannot achieve the automatic trim function. Under automatic flight control, when working in heading / track holding or horizontal navigation mode, the automatic flight control subsystem will control the rudder and aileron deflection to achieve automatic lateral heading trim with the purpose of maintaining the target heading / track.

[0030] Get the automatic balancing rudder surface command, and set the rudder automatic balancing command storage module and the aileron automatic balancing command storage module in the automatic flight rudder command channel and the aileron command channel in the rudder surface command, respectively, such as Figure 3 When the automatic flight control subsystem is disconnected, the automatic flight rudder command and the aileron command are respectively the rudder automatic trim storage module command and the aileron automatic trim storage module command.

[0031] Step S200, obtaining the rudder automatic balancing storage module instructions and the aileron automatic balancing storage module instructions: identifying the automatic balancing working condition, and recording the current automatic balancing instruction value; the automatic balancing instruction value includes the automatic balancing working condition rudder and aileron automatic flight instruction values ​​at multiple speed points within the aircraft speed range.

[0032] Preferably, the instruction storage process of the automatic balancing instruction storage module is: when the aircraft is in an automatic balancing condition, the current real-time indicated airspeed of the aircraft is obtained, and the current automatic balancing instruction value is recorded; when the aircraft is in a non-automatic balancing condition, the instruction value is not recorded, and the instruction value in the previous automatic balancing condition calculation cycle is maintained.

[0033] Preferably, the rudder automatic trim instruction storage module and the aileron automatic trim instruction storage module both store trim instructions for different aircraft speeds under trim conditions, and the trim instructions are combined with the selected aircraft speed points to form an interpolation table. The automatic trim instruction can be calculated according to the real-time speed of the aircraft through the interpolation table.

[0034] Preferably, the automatic trim working condition judgment logic of the aircraft is: after the aircraft takes off, when the radio altitude is greater than a certain altitude, such as 60m, the pilot will turn on the automatic flight control subsystem. When the lateral mode of the automatic flight control subsystem works in the heading / track holding or horizontal navigation mode, and the wings are level (the roll angle is within ±1°), it is judged that the aircraft is in the automatic trim working condition at this time; otherwise, it is in the non-automatic trim working condition, such as Figure 4 .

[0035] Preferably, the specific method of recording the current automatic trim command value is: when the aircraft is in the automatic trim working condition, select speed points at intervals of a certain value within the flight speed range of the aircraft, thereby selecting several speed points, and respectively recording the aileron and rudder commands when the aircraft speed reaches each speed point. The speed interval value and speed point can be adaptively adjusted according to different aircraft.

[0036] Preferably, each certain value interval is specifically: within the flight speed range, each interval of 50km / h records the rudder automatic balancing storage module instructions and the aileron automatic balancing storage module instructions. For example, if the aircraft speed range is 300km / h to 500km / h, when the aircraft speed reaches 300±5km / h, 350±5km / h, 400±5km / h, 450±5km / h, 500±5km / h (±5km / h is the speed point judgment error range), and after keeping it for 2s, record the current rudder instruction and aileron instruction, and store them in the rudder automatic balancing instruction storage module and the aileron automatic balancing instruction storage module respectively. The speed interval and speed point can be adaptively adjusted according to different aircraft, but the overall idea remains unchanged.

[0037] If the aircraft speed does not pass a certain speed point, the aileron and rudder commands of the speed point that has not been passed will remain greater than the recorded values ​​of the rudder commands of the next speed point of the speed point. For example, if the aircraft does not pass the speed of 300km / h under the automatic trimming condition, the corresponding aileron and rudder stored values ​​of the speed of 300km / h will remain the same as the speed of 350k / h; if the aircraft does not pass the speed of 300km / h and 350km / h under the automatic trimming condition, the corresponding aileron and rudder stored values ​​of the speed of 300km / h and 350km / h will remain the same as the speed of 450k / h, and so on. This is because the higher the speed of the aircraft, the higher the efficiency of the rudder, and the smaller the required trim rudder deflection angle. For example, the trim rudder deflection angle at a speed of 300km / h is greater than that at a speed of 350km / h. If the aileron and rudder commands of the speed point that has not been passed are kept smaller than the recorded values ​​of the rudder commands of the speed point, the trim rudder deflection will be larger, resulting in "over-trim", which will cause the aircraft to produce an unexpected response. Therefore, the aileron and rudder commands at the speed points that have not been passed are kept greater than the recorded values ​​of the rudder commands at the speed points to achieve "under-trim" control and ensure that the aircraft responds as expected.

[0038] Step S300, obtaining the rudder and aileron command values ​​of the automatic balancing working condition at multiple speed points within the aircraft speed range, such as the rudder and aileron command values ​​of the automatic balancing working condition at 300km / h, 350km / h, 400km / h, 450km / h, and 500km / h, as shown in Table 1. The values ​​in Table 1 are for illustration only, and the values ​​may vary for different aircrafts.

[0039] Table 1 Examples of stored auto-trim rudder and aileron command values ​​at speed points

[0040] Speed ​​Points Rudder command in auto trim condition Aileron commands for automatic trim conditions 300km / h 3° 2.5° 350km / h 2.5° 2° 400km / h 2° 1.5° 450km / h 1.5° 1° 500km / h 1° 0.5°

[0041] According to the rudder and aileron command values ​​of the automatic trim working condition, a linear interpolation table is established, and the interpolation variable is the aircraft indicated airspeed. When the automatic flight control subsystem is disconnected, a linear interpolation calculation is performed based on the aircraft's current real-time aircraft indicated airspeed to obtain the rudder and aileron trim commands required at the current aircraft indicated airspeed. The rudder and aileron trim commands are used to control the deflection of the rudder surface, thereby ensuring that the aircraft's lateral heading can be trimmed under manual flight control.

[0042] In summary, through the above design, the aircraft can automatically balance the lateral and heading asymmetry when in manual flight control mode, reducing the pilot's control burden. This method does not require any hardware modification. According to this method, the lateral and heading automatic balancing related function modules can be added on the basis of the existing flight control law architecture to save modification costs.

[0043] Finally, it should be noted that: the drawings of the embodiments disclosed in the present invention only involve structures related to the embodiments disclosed in the present invention, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

[0044] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for asymmetric lateral and directional self-balancing of a large aircraft, characterized in that: include: A rudder automatic trim command storage module and an aileron automatic trim command storage module are respectively provided in the automatic flight rudder command channel and the aileron command channel; When the automatic flight control subsystem is disconnected, the automatic flight rudder command and the aileron command are respectively the rudder automatic trim storage module command and the aileron automatic trim storage module command; Obtaining the rudder automatic trim storage module instructions and the aileron automatic trim storage module instructions: identifying the automatic trim working condition and recording the current automatic trim instruction value; the automatic trim instruction value includes the automatic trim working condition rudder and aileron automatic flight instruction values ​​at multiple speed points within the aircraft speed range; The rudder and aileron command values ​​of the automatic trim working condition at multiple speed points within the aircraft speed range are obtained; a linear interpolation table is established based on the rudder and aileron command values ​​of the automatic trim working condition, and the interpolation variable is the aircraft indicated airspeed; when the automatic flight control subsystem is disconnected, a linear interpolation calculation is performed based on the aircraft's current real-time aircraft indicated airspeed to obtain the rudder and aileron trim commands required at the current aircraft indicated airspeed, and the rudder and aileron trim commands are used to control the deflection of the control surface.

2. The large aircraft asymmetric lateral heading self-balancing method as claimed in claim 1, characterized in that: The instruction storage process of the automatic trim instruction storage module is as follows: when the aircraft is in the automatic trim working condition, the current real-time indicated airspeed of the aircraft is obtained, and the current automatic trim instruction value is recorded; when the aircraft is in the non-automatic trim working condition, the instruction value is not recorded, and the instruction value in the previous automatic trim working condition calculation cycle is maintained.

3. The large aircraft asymmetric lateral self-balancing method as claimed in claim 2, characterized in that: The rudder automatic trim command storage module and the aileron automatic trim command storage module both store trim commands at different aircraft speeds under trim conditions, and the trim commands are combined with the selected aircraft speed points to form an interpolation table; The automatic trim command can be calculated based on the real-time speed of the aircraft through the interpolation table.

4. The large aircraft asymmetric lateral and heading self-balancing method as claimed in claim 1, characterized in that: The logic for determining the automatic trim condition of the aircraft is as follows: after the aircraft takes off, when the radio altitude is greater than a certain altitude, the pilot will connect the automatic flight control subsystem. When the lateral mode of the automatic flight control subsystem is working in heading / track holding, or horizontal navigation mode, and the wings are level, it is determined that the aircraft is in an automatic trim condition; otherwise, it is in a non-automatic trim condition.

5. The large aircraft asymmetric lateral and heading self-balancing method as claimed in claim 1, characterized in that: The specific method for recording the current automatic trim command value is: when the aircraft is in the automatic trim working condition, select speed points at certain intervals within the flight speed range of the aircraft, thereby selecting several speed points, and record the aileron and rudder commands when the aircraft speed reaches each speed point respectively.

6. The large aircraft asymmetric lateral and heading self-balancing method as claimed in claim 5, characterized in that: The speed interval values ​​and speed points can be adaptively adjusted according to different aircraft.

7. The large aircraft asymmetric lateral and heading self-balancing method as claimed in claim 5, characterized in that: If the aircraft speed does not pass a certain speed point, the aileron and rudder commands at the speed point that has not been passed will remain greater than the recorded values ​​of the rudder commands at the next speed point of that speed point.

8. The large aircraft asymmetric lateral and heading self-balancing method as claimed in claim 5, characterized in that: The specific value at each certain interval is: within the flight speed range, each interval of 50 km / h records the rudder automatic balancing storage module command and the aileron automatic balancing storage module command respectively.

9. The large aircraft asymmetric lateral and heading self-balancing method as claimed in claim 8, characterized in that: After the aircraft speed reaches each speed point and remains at that speed for 2 seconds, the current rudder automatic trim command and aileron automatic trim command are recorded and stored in the rudder automatic trim command storage module and the aileron automatic trim command storage module respectively.

10. The large aircraft asymmetric lateral and heading self-balancing method as claimed in claim 1, characterized in that: Under automatic flight control, the rudder and aileron commands generated by the automatic flight control subsystem will be superimposed with the commands in the manual flight control subsystem to generate the final rudder commands; the superimposed commands include automatic flight rudder commands, manual flight rudder commands, manual flight aileron commands and automatic flight aileron commands.

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