State estimation method and device based on helicopter main rotor system twin model

Abstract

The application relates to the technical field of helicopters, in particular to a state estimation method and device based on a twin model of a main rotor system of a helicopter, wherein the method comprises the following steps: acquiring a current known state of the main rotor system of the helicopter; inputting the current known state into a twin model of the main rotor system of the helicopter, and the twin model calculating a current length of a collective pitch control rod of the main rotor system of the helicopter; inputting the current known state and the current length of the collective pitch control rod into the twin model, and the twin model calculating a corresponding pitch angle of the main rotor system of the helicopter under a current flapping angle; inputting a plurality of flapping positions of a rotor of the main rotor system of the helicopter and the current length of the collective pitch control rod into the twin model, and the twin model calculating an attitude of a current swash plate of the main rotor system of the helicopter. Thus, the length of the collective pitch control rod, the pitch angle of the rotor and the attitude of the swash plate cannot be directly and accurately measured, the risk coefficient is high when the collective pitch control rod is adjusted by manually lifting a support arm, and the workload is large.

Description

Technical Field

[0001] This application relates to the field of helicopter technology, and in particular to a state estimation method and apparatus based on a twin model of a helicopter main rotor system. Background Technology

[0002] The helicopter main rotor hub system mainly consists of a control system, actuators, swashplates (rotating and stationary), pitch control rods, booms, and rotors. These components are interconnected through mechanical, hydraulic, or electric means to enable the helicopter's flight operations.

[0003] The entire long drivetrain includes the control system, actuators, swashplate's rotating and stationary disks, pitch control rod, outriggers, and rotor. Due to structural coupling, with a fixed pitch control rod and swashplate attitude, different rotor flapping angles will correspond to different pitch angles. Therefore, the nominal pitch angle is the pitch angle when the outriggers reach their upper flapping limit. Thus, in the helicopter main rotor hub system, the attitudes of the pitch control rod and swashplate are mutually influential. When the pitch control rod length and swashplate attitude are fixed, different rotor flapping angles will correspond to different pitch angles.

[0004] The length of the pitch control linkage, the rotor pitch angle, and the attitude of the swashplate are crucial parameters for helicopter pitch control, often requiring precise estimation. However, currently, there are no instruments installed on the helicopter rotor hub to directly measure their states, making measurement inconvenient. Due to the complexity of the rotor hub structure, the length of the pitch control linkage and the attitude of the swashplate are difficult to measure directly and accurately. Furthermore, currently, measuring the pitch angle requires workers to lift the heavy boom to the upper swing limit position and then place an optical quadrant on the blade for measurement. It is not possible to directly obtain the upper swing limit position pitch angle from the free-hanging pitch angle. This means that after each system state change, the boom needs to be lifted again to obtain the changed pitch angle, increasing the workload. Summary of the Invention

[0005] This application provides a state estimation method and device based on a twin model of a helicopter main rotor system to solve the problems that the length of the pitch control rod, the rotor pitch angle and the attitude of the swashplate cannot be directly and accurately measured, and that the adjustment by manually lifting the boom is dangerous and labor-intensive.

[0006] The first aspect of this application provides a state estimation method based on a twin model of a helicopter main rotor system, comprising the following steps: obtaining the current known state of the helicopter main rotor system; inputting the current known state into the twin model of the helicopter main rotor system, wherein the twin model calculates the current pitch control stick length of the helicopter main rotor system; inputting the current known state and the current pitch control stick length into the twin model, wherein the twin model calculates the rotor pitch angle corresponding to the helicopter main rotor system at the current flapping angle; inputting multiple flapping positions of one rotor of the helicopter main rotor system and the current pitch control stick length into the twin model, wherein the twin model calculates the current attitude of the rotating swashplate of the helicopter main rotor system.

[0007] Optionally, the twin model calculates the current pitch control stick length of the helicopter main rotor system, including: identifying the flapping angle, pitch angle, and swashplate attitude of the currently known state; setting the corresponding coordinate system of the twin model, and calculating the current pitch control stick length based on the corresponding coordinate system, the flapping angle, and the pitch angle.

[0008] Optionally, calculating the current pitch control stick length based on the corresponding coordinate system, the flapping angle, and the pitch angle includes: obtaining the pitch angle coordinate system, flapping coordinate system, and hub coordinate system of the helicopter main rotor system; rotating the pitch angle coordinate system and the flapping coordinate system around the y-axis of the hub coordinate system by the right-hand rule according to the angle corresponding to the flapping angle to obtain a first rotation matrix; rotating the pitch angle coordinate system around the x-axis of its own coordinate system by the right-hand rule according to the angle corresponding to the pitch angle to obtain a second rotation matrix; setting a first position of the top coordinate system in the corresponding coordinate system relative to the hub coordinate system, and calculating a first position vector based on the first rotation matrix, the second rotation matrix, and the first position; querying the attitude of the swashplate to obtain a second position vector of the bottom coordinate system in the corresponding coordinate system relative to the hub coordinate system, and calculating the current pitch control stick length based on the first position vector and the second position vector.

[0009] Optionally, the twin model calculates the pitch angle of the helicopter main rotor system at the current flapping angle, including: identifying the flapping angle and the attitude of the swashplate in the current known state; setting the corresponding coordinate system of the twin model, and calculating the pitch angle corresponding to the current flapping angle based on the corresponding coordinate system, the current pitch control stick length, the flapping angle and the attitude of the swashplate.

[0010] Optionally, calculating the blade pitch angle corresponding to the current flapping angle based on the corresponding coordinate system, the current pitch control stick length, the flapping angle, and the attitude of the rotating swashplate includes: acquiring the blade pitch angle coordinate system, flapping coordinate system, and swashplate attitude adjustment coordinate system of the helicopter main rotor system, and identifying the translation, roll, and pitch angles of the rotating swashplate attitude; translating the swashplate attitude adjustment coordinate system along its z-axis based on the translation amount, rotating the swashplate attitude adjustment coordinate system around its x-axis based on the roll angle, and rotating the swashplate attitude adjustment coordinate system around the y-axis of the translation coordinate system based on the pitch angle. The axis is rotated, and all rotations are performed according to the right-hand rule; the third position vector of the top coordinate system relative to the pitch angle coordinate system and the fourth position vector of the bottom coordinate system relative to the swing coordinate system are found in the corresponding coordinate system; the pitch angle coordinate system is rotated around the x-axis of its own coordinate system by the angle corresponding to the pitch angle according to the right-hand rule to obtain the third rotation matrix; the motion constraint equation is established using the condition of the current variable pitch lever length; the motion constraint equation is solved according to the first position vector, the second position vector and the third rotation matrix to obtain the pitch angle corresponding to the current swing angle.

[0011] Optionally, the twin model calculates the current attitude of the rotating swashplate of the helicopter main rotor system, including: setting the corresponding coordinate system of the twin model; and calculating the current attitude of the rotating swashplate based on the multiple flapping positions, the current pitch control rod length, and the corresponding coordinate system.

[0012] Optionally, calculating the attitude of the current rotating swashplate based on the multiple waving positions, the current pitch control stick length, and the corresponding coordinate system includes: obtaining the swashplate attitude adjustment coordinate system and the swashplate translation coordinate system of the helicopter main rotor system; based on the multiple waving positions, querying the fifth position vector in the corresponding coordinate system relative to the swashplate attitude adjustment coordinate system, and the sixth position vector of the top coordinate system in the corresponding coordinate system at each position in the swashplate translation coordinate system; establishing a function of the rotation matrix under any rotor hub rotation angle; establishing an objective function of a nonlinear optimization problem based on the function, the fifth position vector, and the sixth position vector, and deriving the Jacobian matrix function of the objective function; and iteratively solving the objective function to obtain the attitude of the current rotating swashplate.

[0013] A second aspect of this application provides a state estimation device based on a twin model of a helicopter main rotor system, comprising: an acquisition module for acquiring the current known state of the helicopter main rotor system; a first estimation module for inputting the current known state into the twin model of the helicopter main rotor system, wherein the twin model calculates the current pitch control stick length of the helicopter main rotor system; a second estimation module for inputting the current known state and the current pitch control stick length into the twin model, wherein the twin model calculates the pitch angle corresponding to the helicopter main rotor system at the current flapping angle; and a third estimation module for inputting multiple flapping positions of one rotor of the helicopter main rotor system and the current pitch control stick length into the twin model, wherein the twin model calculates the current attitude of the rotating swashplate of the helicopter main rotor system.

[0014] Optionally, the first estimation module is further configured to: identify the swing angle, pitch angle, and swashplate attitude of the current known state; set the corresponding coordinate system of the twin model, and calculate the current pitch lever length based on the corresponding coordinate system, the swing angle, and the pitch angle.

[0015] Optionally, the second estimation module is further configured to: obtain the pitch angle coordinate system, flapping coordinate system, and hub coordinate system of the helicopter main rotor system; rotate the pitch angle coordinate system and the flapping coordinate system around the y-axis of the hub coordinate system according to the right-hand rule by the angle corresponding to the flapping angle to obtain a first rotation matrix; rotate the pitch angle coordinate system around the x-axis of its own coordinate system according to the right-hand rule by the angle corresponding to the pitch angle to obtain a second rotation matrix; set a first position of the top coordinate system in the corresponding coordinate system relative to the hub coordinate system, and calculate a first position vector based on the first rotation matrix, the second rotation matrix, and the first position; query the attitude of the swashplate to obtain a second position vector of the bottom coordinate system in the corresponding coordinate system relative to the hub coordinate system, and calculate the current pitch control stick length based on the first position vector and the second position vector.

[0016] Optionally, the second estimation module is further configured to: identify the swing angle and the attitude of the swashplate in the current known state; set the corresponding coordinate system of the twin model, and calculate the pitch angle corresponding to the current swing angle based on the corresponding coordinate system, the current pitch lever length, the swing angle and the attitude of the swashplate.

[0017] Optionally, the second estimation module is further configured to: acquire the pitch angle coordinate system, flapping coordinate system, and swashplate attitude coordinate system of the helicopter main rotor system, and identify the translation, roll angle, and pitch angle of the rotating swashplate; translate the swashplate attitude coordinate system along its z-axis according to the translation, rotate the swashplate attitude coordinate system around its x-axis according to the roll angle, and rotate the swashplate attitude coordinate system around the y-axis of the swashplate translation coordinate system according to the pitch angle, all according to the right-hand rule; and query the corresponding coordinate system. The third position vector of the top coordinate system relative to the pitch angle coordinate system, and the fourth position vector of the bottom coordinate system relative to the swing coordinate system; the pitch angle coordinate system is rotated around its own x-axis by the right-hand rule to obtain the angle corresponding to the pitch angle, thus obtaining the third rotation matrix; the motion constraint equation is established using the condition of the current pitch lever length; the motion constraint equation is solved based on the first position vector, the second position vector, and the third rotation matrix to obtain the pitch angle corresponding to the current swing angle.

[0018] Optionally, the third estimation module is further configured to: set the corresponding coordinate system of the twin model; and calculate the current attitude of the rotating tilt disk based on the multiple swing positions, the current variable pitch lever length, and the corresponding coordinate system.

[0019] Optionally, the third estimation module is further configured to: obtain the swashplate attitude coordinate system and the swashplate translation coordinate system of the helicopter main rotor system; based on the multiple flapping positions, query the fifth position vector in the corresponding coordinate system relative to the swashplate attitude coordinate system, and the sixth position vector of the top coordinate system in the corresponding coordinate system at each position in the swashplate translation coordinate system; establish a function of the rotation matrix under any rotor hub rotation angle, establish an objective function of the nonlinear optimization problem based on the function, the fifth position vector, and the sixth position vector, and derive the Jacobian matrix function of the objective function; and perform iterative solution based on the objective function to obtain the attitude of the current rotating swashplate.

[0020] A third aspect of this application provides a helicopter main rotor system, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the program to implement the state estimation method based on a twin model of the helicopter main rotor system as described above.

[0021] A fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the state estimation method based on a twin model of a helicopter main rotor system as described above.

[0022] Therefore, this application has at least the following beneficial effects:

[0023] This application's embodiments can use twin models to calculate the pitch control rod length, flapping angle, pitch angle, and swashplate attitude, accurately determining the pitch control rod length for subsequent rod length adjustments; it can also calculate the pitch angle under any conditions for simulated operation of the lift system, simulating the lifting of the outrigger based on existing parameters instead of manually lifting the physical outrigger. Once the upper flapping limit of the outrigger at a certain position is determined, subsequent measurements do not require lifting it to the upper limit again, saving manpower from repeatedly lifting the outrigger. Accurate calculation of the swashplate attitude based on the pitch and flapping angles provides a theoretical basis for obtaining different collective and variable pitches. Therefore, it solves the technical problems of the inability to directly and accurately measure the pitch control rod length, rotor pitch angle, and swashplate attitude, and the high risk and large workload associated with manually lifting the outrigger for adjustments.

[0024] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0025] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0026] Figure 1 This is a flowchart of a state estimation method based on a twin model of a helicopter main rotor system provided according to an embodiment of this application;

[0027] Figure 2 This is a schematic diagram illustrating the important coordinate system settings of the digital twin model used according to the embodiments of this application;

[0028] Figure 3 This is a schematic diagram illustrating the effect of the rotation of the propeller hub and the rotating swashplate on the spatial pose relationship according to an embodiment of this application.

[0029] Figure 4 Example diagram of a state estimation device based on a twin model of a helicopter main rotor system according to an embodiment of this application;

[0030] Figure 5 This is a schematic diagram of the structure of a helicopter main rotor system provided according to an embodiment of this application. Detailed Implementation

[0031] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0032] The following describes a state estimation method and apparatus based on a twin model of a helicopter main rotor system, according to embodiments of this application, with reference to the accompanying drawings. Addressing the problem mentioned in the background art that there are no instruments installed on the helicopter rotor hub to directly measure their states, this application provides a state estimation method based on a twin model of a helicopter main rotor system. In this method, the pitch control rod length, flapping angle, pitch angle, and swashplate attitude are calculated using a twin model to accurately determine the pitch control rod length for subsequent rod length adjustments; the pitch angle is calculated for simulated operation of the lift system under any given state; and the boom is simulated to replace manual lifting of the boom itself based on existing parameters. Once the upper flapping limit of the boom at a certain position is determined, subsequent measurements do not require raising it to the upper limit, saving manpower from repeatedly raising the boom. Accurate calculation of the swashplate attitude based on the pitch angle and flapping angle provides a theoretical basis for obtaining different collective pitch and variable pitch. This solves the problems of the inability to directly and accurately measure the length of the pitch control rod, the rotor pitch angle, and the attitude of the swashplate, and the high risk and large workload when adjusting by manually lifting the boom.

[0033] Specifically, Figure 1 This is a flowchart illustrating a state estimation method based on a twin model of a helicopter main rotor system, provided in an embodiment of this application.

[0034] like Figure 1 As shown, the state estimation method based on the twin model of the helicopter main rotor system includes the following steps:

[0035] In step S101, the current known state of the helicopter main rotor system is obtained.

[0036] The known states can include the length of the variable pitch lever, the swing angle, the pitch angle, and the attitude of the swashplate.

[0037] It is understood that the embodiments of this application can obtain the current known state of the helicopter main rotor system, helping the helicopter to maintain stable flight under various weather conditions.

[0038] In step S102, the current known state is input into the twin model of the helicopter main rotor system, and the twin model calculates the current pitch control rod length of the helicopter main rotor system.

[0039] Among them, the twin model can be based on the actual operating data of the main rotor system, and use digital twin technology to map the actual physical object into the virtual space to form a digital twin, so as to simulate and predict the performance, structure, health status, etc. of the main rotor system.

[0040] It is understood that, in the embodiments of this application, the current known state can be input into the twin model of the helicopter main rotor system to calculate the current pitch control stick length. Since the twin model monitors and predicts the state of the main rotor system in real time, it can provide the optimal pitch control stick length according to flight conditions and mission requirements, thereby optimizing the helicopter's stick length.

[0041] It should be noted that, as Figure 2 As shown, the twin model is further explained in detail: when setting the waving angle β... w At that time, the R and W systems will rotate together around the y-axis of the O system; set the propeller pitch angle α. r At this time, the R-axis rotates around its own x-axis, while the W-frame remains stationary. This means the W-frame only reflects the effect of the flapping angle, while the R-frame reflects the combined effect of the flapping and pitch angles. Furthermore, the x-axis of the R and W-frames always coincide. The T and M-frames are rigidly connected to the R-frame, meaning the descriptions of the T and M-frames within the R-frame do not change with the R-frame's attitude. The origins of the W and R-frames are fixed in the O-frame. The O-frame rotates around its own z-axis with the rotation angle θ. The PP-frame's attitude remains consistent with the O-frame, maintaining a zero-tilt attitude. The PP-frame only moves along its own z-axis, reflecting the swashplate translation x0. The PR-frame's attitude is consistent with the PP-frame at zero tilt. With a roll angle α0, the PR-frame rotates α0 around its own x-axis. With a pitch angle β0, the PR-frame rotates β0 around the PP-frame's y-axis. The B-frame is rigidly connected to the PR-frame, meaning the description of the B-frame within the PR-frame does not change with the PR-frame's attitude.

[0042] In this embodiment of the application, the twin model calculates the current pitch control stick length of the helicopter main rotor system, including: identifying the flapping angle, pitch angle and swashplate attitude of the current known state; setting the corresponding coordinate system of the twin model, and calculating the current pitch control stick length based on the corresponding coordinate system, flapping angle and pitch angle.

[0043] The corresponding coordinate system may include the top coordinate system of the current twin model and the bottom coordinate system of the current twin model.

[0044] It is understood that, in the embodiments of this application, the corresponding coordinate system pose of the twin model can be set, and the current variable-pitch lever length can be calculated based on the coordinate system, the swing angle, and the pitch angle for subsequent lever length adjustment to obtain the length adjustment amount. The swing angle can be set as β. w The propeller pitch angle can be set as α. rThe position vector of the current top coordinate system relative to the hub coordinate system can be set as t. p In the current model, the position vector of the bottom coordinate system relative to the hub coordinate system can be set as b. p The specific steps include:

[0045] S1, based on the waving angle β w The value of the rotation β of the pitch angle coordinate system and the flapping coordinate system around the y-axis of the hub coordinate system according to the right-hand rule w ;

[0046] S2, based on the pitch angle α r The value of the pitch angle coordinate system will rotate by α around the x-axis of the current coordinate system according to the right-hand rule. r ;

[0047] S3. Calculate the position vector t of the current top coordinate system relative to the hub coordinate system. p Query the position vector b of the bottom coordinate system relative to the hub coordinate system in the current model. p ;

[0048] S4, Calculate t p With b p The Euclidean distance between them is the length of the pitch control rod.

[0049] In this embodiment, calculating the current pitch control stick length based on the corresponding coordinate system, flapping angle, and pitch angle includes: obtaining the pitch angle coordinate system, flapping coordinate system, and hub coordinate system of the helicopter main rotor system; rotating the pitch angle coordinate system and the flapping coordinate system around the y-axis of the hub coordinate system according to the right-hand rule by the angle corresponding to the flapping angle to obtain a first rotation matrix; rotating the pitch angle coordinate system around the x-axis of its own coordinate system according to the right-hand rule by the angle corresponding to the pitch angle to obtain a second rotation matrix; setting a first position of the top coordinate system in the corresponding coordinate system relative to the hub coordinate system, and calculating a first position vector based on the first rotation matrix, the second rotation matrix, and the first position; querying the attitude of the rotating swashplate to obtain a second position vector of the bottom coordinate system in the corresponding coordinate system relative to the hub coordinate system, and calculating the current pitch control stick length based on the first position vector and the second position vector.

[0050] It is understood that, in order to determine the current attitude of the main rotor system, this application embodiment needs to rotate the pitch angle coordinate system and the flapping coordinate system. The first rotation matrix is ​​obtained by rotating the pitch angle coordinate system around the y-axis of the hub coordinate system according to the right-hand rule. The second rotation matrix is ​​obtained by rotating the pitch angle coordinate system around the x-axis of its own coordinate system according to the right-hand rule. The first position vector is calculated based on the first rotation matrix, the second rotation matrix and the set first position. The current pitch control rod length is calculated based on the first position vector and the set second position vector.

[0051] The basic rotation matrix around the coordinate axis used in this application embodiment is defined as follows: Let the rotation angle be φ, then the matrix for rotating around its own x-axis is R. x (φ), the matrix of rotation about its own y-axis is R. y (φ), the matrix of rotation about its own z-axis is R. z (φ), which will be used here in the following text:

[0052]

[0053] First, based on the swing angle β w The value of β rotates the R and W systems about the y-axis of the O system according to the right-hand rule. w The corresponding rotation matrix is ​​R. y (β w According to the pitch angle α r The value of α will rotate the R-frame about its current x-axis according to the right-hand rule. r The corresponding rotation matrix is ​​R. x (α r Let the position of system T in system R be t. p0 After the above transformation, the position vector of the T system in the O system is t. p =R y (β w )R x (α r )t p0 When adjusting the length of the variable pitch lever, the tilting disk is usually placed at the pose zero point. Therefore, the position vector b of the B system in the O system can be directly found from the twin model. p The length L of the variable pitch tie rod is:

[0054] L=||R y (β w )R x (α r )t p0 -b p ||2 (1)

[0055] In step S103, the current known state and the current pitch control rod length are input into the twin model, and the twin model calculates the pitch angle of the helicopter main rotor system at the current flapping angle.

[0056] The current waving angle can be determined according to the actual situation and is not specifically limited.

[0057] It is understood that, in this embodiment of the application, the current known state and the current pitch lever length are input into the twin model to calculate the corresponding pitch angle under the current swing angle, and the pitch angle under any state is calculated for the simulated operation of the lift system. The outrigger is simulated to lift the outrigger body according to the existing parameters instead of manually lifting the outrigger body. Once the upper swing limit of the outrigger is determined to a certain position, the subsequent measurement process does not need to lift it to the upper limit, saving the manpower of repeatedly lifting the outrigger.

[0058] In this embodiment of the application, the twin model calculates the pitch angle of the helicopter main rotor system at the current flapping angle, including: identifying the flapping angle and the attitude of the swashplate in the current known state; setting the corresponding coordinate system of the twin model, and calculating the pitch angle at the current flapping angle based on the corresponding coordinate system, the current pitch control stick length, the flapping angle and the attitude of the swashplate.

[0059] It is understood that the embodiments of this application can set the coordinate system pose of the twin model, and calculate the corresponding pitch angle under the current swing angle based on the coordinate system, the current pitch control length, the swing angle, and the attitude of the swashplate. The swashplate translation can be set to x0, the swashplate roll angle can be set to α0, and the swashplate pitch angle can be set to β0. Specific steps include:

[0060] S1. Based on the known information, set the waving angle β. w The swashplate attitude adjustment coordinate system is translated x0 along its own z-axis according to the swashplate translation amount x0. The swashplate attitude adjustment coordinate system is rotated α0 around its own x-axis according to the swashplate roll angle α0. The swashplate attitude adjustment coordinate system is rotated β0 around the y-axis of the swashplate translation coordinate system according to the pitch angle β0. All rotations are performed according to the right-hand rule.

[0061] S2. Query the position vector t of the top coordinate system relative to the pitch angle coordinate system in the current model. p0 The position vector b of the bottom coordinate system relative to the waving coordinate system p ;

[0062] S3, Let the pitch angle be α. r The rotation matrix about the x-axis is R x (α r Using the condition that the length of the variable-pitch rod is L, establish the motion constraint equations:

[0063] S4. Solve the motion constraint equations to obtain the propeller pitch angle α. r .

[0064] In this embodiment, the calculation of the blade pitch angle corresponding to the current flapping angle based on the corresponding coordinate system, the current pitch control stick length, the flapping angle, and the attitude of the rotating swashplate includes: acquiring the blade pitch angle coordinate system, flapping coordinate system, and swashplate attitude adjustment coordinate system of the helicopter main rotor system, and identifying the translation, roll, and pitch angles of the rotating swashplate attitude; translating the swashplate attitude adjustment coordinate system along its own z-axis based on the translation amount, rotating the swashplate attitude adjustment coordinate system around its own x-axis based on the roll angle, and rotating the swashplate attitude adjustment coordinate system around the swashplate translation coordinate system based on the pitch angle. Rotate along the y-axis, always according to the right-hand rule; query the third position vector of the top coordinate system relative to the pitch angle coordinate system and the fourth position vector of the bottom coordinate system relative to the flapping coordinate system in the corresponding coordinate system; rotate the pitch angle coordinate system around its own x-axis according to the right-hand rule to obtain the third rotation matrix; establish the motion constraint equation using the current pitch lever length; solve the motion constraint equation based on the first position vector, the second position vector, and the third rotation matrix to obtain the pitch angle corresponding to the current flapping angle.

[0065] It is understood that, in the embodiments of this application, the motion constraint equations can be solved based on the set first position vector, second position vector, and third rotation matrix to obtain the propeller pitch angle corresponding to the current flapping angle. The specific process is as follows:

[0066] With the pitch control rod length determined, calculate the pitch angle α under any system state. r First, based on the known information, set the swing angle β. w The PR system is translated x0 along its z-axis based on the swashplate translation x0, rotated α0 around its x-axis based on the swashplate roll angle α0, and rotated β0 around the y-axis of the PP system based on the pitch angle β0. Then, the position vector t of the T system relative to the R system in the current model is queried. p0 =[xyz] T The position vector b of system B relative to system W p0 =[x0 y0 z0] T .

[0067] Let the pitch angle be α. r The rotation matrix about the x-axis is R x (α r Using the condition that the length of the variable-pitch rod is L, establish the motion constraint equations:

[0068]

[0069] Expanding (2) gives:

[0070] (x-x0) 2 +(ycosα r -zsinα r -y0)2 +(ysinα r +zcosα r -z0) 2 =L 2 (3)

[0071] (3) contains α r With no α r Simplifying the terms to both sides, we get:

[0072] Asinα r +Bcosα r =C (4)

[0073] (4) In this case, A = 2yz0 - 2zy0, B = 2yy0 + 2zz0.

[0074] Solving (4) will yield α. r (4) Can be transformed into Where tanφ=BA, so that the pitch angle α r This aligns with common sense, and can be solved logically as follows (4):

[0075] like Then let like Then let And φ = arctan(B / A). If |a1-φ| > |a2-φ|, then α r = a2-φ, otherwise α r = a1 - φ. Thus, the propeller pitch angle α is obtained. r .

[0076] In step S104, the multiple flapping positions of one rotor of the helicopter main rotor system and the current pitch control stick length are input into the twin model, and the twin model calculates the current attitude of the rotating swashplate of the helicopter main rotor system.

[0077] It is understood that, in the embodiments of this application, the attitude of the current rotating swashplate of the helicopter main rotor system can be calculated by inputting multiple waving positions and the current pitch lever length into the twin model, thereby providing a theoretical basis for how to control the rotating swashplate.

[0078] In this embodiment of the application, the twin model calculates the current attitude of the rotating swashplate of the helicopter main rotor system, including: setting the corresponding coordinate system of the twin model; and calculating the current attitude of the rotating swashplate based on multiple flapping positions, the current pitch control rod length, and the corresponding coordinate system.

[0079] Among them, multiple waving positions can be specifically marked, such as rotating to 0 degrees, 90 degrees, 180 degrees or 270 degrees of the rotor hub rotation angle.

[0080] It is understood that, in the embodiments of this application, the current attitude of the rotating tilting disk can be calculated based on multiple swing positions, the current pitch lever length, and the corresponding coordinate system. The position vector of the bottom coordinate system relative to the tilting disk attitude adjustment coordinate system can be set as b. p0 The position vector of the top coordinate system in the tilting disk translation coordinate system can be set as t. pi For i = 1, 2, 3, 4, the specific steps include:

[0081] S1. Rotate one rotor to four unrelated flapping positions with hub rotation angles of 0 degrees, 90 degrees, 180 degrees, and 270 degrees, and query the record of the position vector b of the bottom coordinate system relative to the swashplate attitude control coordinate system. p0 And the position vector t of the top coordinate system in the tilting disk translation coordinate system at each location. pi , i = 1, 2, 3, 4;

[0082] S2, Let vector b p0 The position vector in the tilting disk translation coordinate system at four unrelated positions is b. pi i = 1, 2, 3, 4, four b pi All are implicitly related to the attitudes of the swashplate α0, β0, and x0. Because the swashplate rotates synchronously with the propeller hub under the action of the torque arm, but its rotation axis no longer coincides with the main rotation axis of the propeller hub, this results in the following at the four positions: b... pi With b p0 rotation matrix They are not the same. Establish the rotation matrix for any rotor hub rotation angle θ. The function;

[0083] S3, according to S2 For i = 1, 2, 3, 4, establish the objective function f for the nonlinear optimization problem. panfit (α0,β0,x0), is a vector function, where t p ,b p0 L, θ are the input values, and the dimension represents the number of unrelated rotor hub rotation positions, with each dimension corresponding to a position θ. i Residual at:

[0084] S4. The above f is derived. panfit The Jacobian matrix function Ja(α0,β0,x0) of (α0,β0,x0) is used for the single-step iteration of the subsequent optimization algorithm;

[0085] S5, f panfit Substituting (α0,β0,x0) and Ja(α0,β0,x0) into the Levenberg-Marquardt method, an optimization algorithm is used to iteratively solve for the tilting disk attitude α0,β0,x0.

[0086] In this embodiment, the attitude of the current rotating swashplate is calculated based on multiple flapping positions, the current pitch control stick length, and the corresponding coordinate system. This includes: obtaining the swashplate attitude adjustment coordinate system and the swashplate translation coordinate system of the helicopter main rotor system; based on multiple flapping positions, querying the fifth position vector in the corresponding coordinate system relative to the swashplate attitude adjustment coordinate system, and the sixth position vector of the top coordinate system in the corresponding coordinate system at each position relative to the swashplate translation coordinate system; establishing a function of the rotation matrix under any rotor hub rotation angle; establishing an objective function for a nonlinear optimization problem based on the function, the fifth position vector, and the sixth position vector, and deriving the Jacobian matrix function of the objective function; and iteratively solving the objective function to obtain the attitude of the current rotating swashplate.

[0087] It is understood that, in the embodiments of this application, an objective function for a nonlinear optimization problem can be established based on the function, the fifth position vector, and the sixth position vector, and the objective function can be iteratively solved to obtain the current attitude of the rotating tilt disk. The specific process is as follows:

[0088] The three-degree-of-freedom attitude of the rotating swashplate is calculated based on data from multiple unrelated locations. First, one rotor is rotated to four unrelated flapping positions with hub rotation angles of 0 degrees, 90 degrees, 180 degrees, and 270 degrees. The position vector b of the B-frame relative to the PR-frame is then retrieved. p0 And the position vector t of the T system in the PP system at each position. pi Let i = 1, 2, 3, 4. Let vector b be... p0 The position vector in the PP system at four unrelated locations is b. pi i = 1, 2, 3, 4, four b pi All are implicitly related to the tilting disk attitudes α0, β0, and x0. To establish the rod length equations in the PP system, it is necessary to determine the rotation matrices from the PR system to the PP system at the four positions. To make b p0 Convert to b pi Because the swashplate rotates synchronously with the propeller hub under the action of the torque arm, but when there is a change in pitch, its rotation axis no longer coincides with the main rotation axis of the propeller hub, resulting in b at four positions. pi With b p0 rotation matrix They are not the same, so it is necessary to establish a rotation matrix for any rotor hub rotation angle θ. The function.

[0089] like Figure 3As shown, A is the rotor hub rotation plane, and B is the rotating swashplate plane with variable pitch. In A, the z-axis of the O system is the rotation axis of the main rotor hub, and in B, the z-axis of the PR system is the rotation axis of the rotating swashplate. Both z-axis are fixed during rotation. 1, 2, 3, and 4 correspond to systems 1, 2, 3, and 4, respectively. Systems 1 and 3 refer to the positions of the O and PR systems when the rotation angle θ is 0 degrees, respectively. Systems 2 and 4 refer to the example positions of the O and PR systems when the rotation angle θ is an arbitrary angle. When the rotation angle θ is 0, the O and PR systems are at positions 1 and 3, respectively. Their x-axis are forced to remain in the same plane due to the presence of the torque arm. According to the definition, it can be directly stated that... However, when the rotation angle θ is not 0, such as when the O-frame and PR-frame are at positions 2 and 4 respectively, the x-axis is still constrained within a plane. In this case, the pitch and roll angles of the 4-frame relative to the 2-frame (the current O-frame) are no longer α0 and β0, then:

[0090]

[0091] Since the z-axis values ​​of the 3rd and 4th systems are the same in the 1st system, the relationship between αβ and α0β0 can be derived.

[0092] The z-axis of the 3 series is R. y (β0)R x The third column of (α0), the z-axis of the 4-system is R. z (θ)R y (β)R x The third column of (α), multiplied by R on both sides. z (θ) -1 The z-axis is the same after that, expand R z (θ) -1 R y (β0)R x (α0) and R y (β)R x The third column of (α) yields...

[0093]

[0094] It is easy to obtain from (6) that

[0095] α=arcsin(sinθsinβ0cosα0+cosθsinα0)

[0096]

[0097] Substituting the result of (7) into equation (5) yields the result.

[0098] according to Get the four positions Establish the objective function f for the nonlinear optimization problem panfit (α0,β0,x0), is a vector function, where t p ,b p0 L, θ are known inputs, and the dimension is the number of unrelated hub rotation positions, with each dimension corresponding to a position θ. i Residual at:

[0099]

[0100] The above f is derived panfit The Jacobian matrix function Ja(α0,β0,x0) is used for the single-step iteration of the subsequent optimization algorithm. Let the position vector t of the T frame relative to the PP frame be... p =[x t y t z t ] T The position vector b of system B relative to system PP p =[xyz] T Then (8) is:

[0101] f panfit (α0,β0,x0) i =(xx) t ) 2 +(yy t ) 2 +(zz t ) 2 -L 2 (9)

[0102] Then it is easy to obtain.

[0103]

[0104] According to the chain rule for differentiation, it is easy to obtain that...

[0105]

[0106] In (11), the M1 matrix on the right represents b. p The Jacobian matrix relative to α, β, x0. Let The first column of the matrix is ​​v a The second column is v b And from (8), we can know Using the general method for finding the Jacobian matrix of a revolute joint, it is easy to obtain that...

[0107] M1 = [v b ×b p v a ×b p (0,0,1)T (12)

[0108] In the M2 matrix, it is clear that we only need to care about the values ​​in the first two rows and two columns.

[0109] In the derivation of (6) and Figure 3 In the analysis, R was obtained yz =R y (β0)R x The z-axis of (α0) and R zyx =R z (θ)R y (β)R x (α) have the same z-axis value, let z be... yx =R yx (1:2,3), z zyx =R zyx (1:2,3), then we have,

[0110]

[0111] Remember z yx The Jacobian relative to α0, β0 is Ja yx , z zyx The Jacobian ratio relative to α, β is Ja zyx It is easy to see that the differential values ​​of the two are the same, therefore we have,

[0112]

[0113] From (14), we can obtain that

[0114]

[0115] It is obvious from (15) that

[0116]

[0117] In summary, combining the results of (10-16), the value of Ja(α0,β0,x0) can be easily obtained.

[0118] Finally, the Levenberg-Marquardt optimization algorithm is used to optimize f. panfit (α0,β0,x0) serves as the objective function, and Ja(α0,β0,x0) is the Jacobian matrix for each iteration. The LM algorithm belongs to the trust-region method, controlling the length of the variable walk within a certain trust region to ensure that the Taylor expansion has a good approximation effect. The LM algorithm uses a damped Gauss-Newton method.

[0119] The problem of solving the attitude problem of a rotating swashplate can be written as:

[0120]

[0121] f panfit (x) First-order Taylor expansion

[0122] f panfit (x+h)=f panfit (x)+Ja(x)h+O(h T h)

[0123] Remove the higher-order terms and substitute them into F(x).

[0124]

[0125] Based on the idea of ​​the damping method, add another damping term.

[0126]

[0127] Take the partial derivative of the above equation and set it to 0:

[0128] (Ja T Ja+μI)h=-Ja T f (17)

[0129] Thus, equation (17) can be used to calculate h, and the increment for each step. The pose α0, β0, x0 of the rotating tilt disk is solved iteratively.

[0130] In summary, the embodiments of this application can address the state estimation problem of important pitch control components in a helicopter main rotor system by using a twin model that is consistent with the real main rotor system and has been established in a computer. The mathematical relationships in the twin model are analyzed, and calculations are made to obtain values ​​including the pitch control rod length, the blade pitch angle in any state, and the swashplate attitude, which are then used as estimates of these quantities in the real main rotor system.

[0131] According to the embodiments of this application, a state estimation method based on a twin model of a helicopter main rotor system can be proposed. This method can perform twin model calculations on parameters such as the pitch control rod length, flapping angle, blade pitch angle, and swashplate attitude to accurately determine the pitch control rod length for subsequent adjustment. It can also calculate the blade pitch angle under any given state for simulated operation of the lift system. By simulating the lifting of the boom based on existing parameters, it replaces manual lifting of the boom. Once the upper flapping limit of the boom at a certain position is determined, subsequent measurements do not require lifting it to the upper limit, saving manpower from repeated boom lifting. Accurate calculation of the swashplate attitude based on the blade pitch angle and flapping angle provides a theoretical basis for obtaining different collective pitch and variable pitch. Therefore, this method solves the problems of the inability to directly and accurately measure the pitch control rod length, rotor blade pitch angle, and swashplate attitude, and the high risk and large workload associated with manually lifting the boom for adjustment.

[0132] The following is a specific embodiment illustrating a state estimation method based on a twin model of a helicopter main rotor system.

[0133] Based on a twin model in the computer that is consistent with the real main rotor system, the data provided in this model serves as the input to the algorithm. Each coordinate system in the model corresponds to the actual degrees of freedom of the main rotor system, and the attitude of each coordinate system can be changed according to the setting of position parameters, simulating the actual attitude adjustment of the main rotor system. Furthermore, the attitude data of each coordinate system in this model can be queried and obtained at any time. This attitude data will serve as the input to the algorithm of this invention.

[0134] The calculation methods for the variable pitch rod length, the propeller pitch angle under any condition, and the swashplate attitude are as follows:

[0135] S1. Based on the current known state of the main rotor system, including flapping angle, pitch angle, and attitude of the rotating swashplate, set the corresponding coordinate system pose of the model, and query the pose of the top and bottom coordinate systems under the same reference coordinate system, and calculate the current pitch linkage length accordingly.

[0136] S2. Based on the current known state of the main rotor system, including the length of the variable pitch rod, the flapping angle, and the attitude of the rotating swashplate, set the corresponding coordinate system pose of the model, and query the pose of the top and bottom coordinate systems under the same reference coordinate system. Based on the condition that the length of the variable pitch rod is constant, establish the motion constraint equation and solve the corresponding blade pitch angle under the current flapping angle.

[0137] S3. Based on the current known state of the main rotor system, i.e., the length of the pitch control rod, estimate the current attitude of the rotating swashplate. Since there are three unknowns in the attitude, rotate one rotor to four unrelated flapping positions. Query and record the position vectors of the top and bottom coordinate systems in the corresponding reference coordinate systems at each position. Establish a nonlinear optimization problem based on the condition that the pitch control rod length is constant. Establish its optimization function and Jacobian matrix function, and use the Levenberg-Marquardt optimization algorithm to solve for the current attitude of the rotating swashplate.

[0138] Next, referring to the accompanying drawings, a state estimation device based on a twin model of a helicopter main rotor system is described according to an embodiment of this application.

[0139] Figure 4 This is a block diagram of a state estimation device based on a twin model of a helicopter main rotor system according to an embodiment of this application.

[0140] like Figure 4 As shown, the state estimation device 10 based on the twin model of the helicopter main rotor system includes: an acquisition module 100, a first estimation module 200, a second estimation module 300, and a third estimation module 400.

[0141] The acquisition module 100 is used to acquire the current known state of the helicopter main rotor system; the first estimation module 200 is used to input the current known state into the twin model of the helicopter main rotor system, and the twin model calculates the current pitch control stick length of the helicopter main rotor system; the second estimation module 300 is used to input the current known state and the current pitch control stick length into the twin model, and the twin model calculates the pitch angle corresponding to the helicopter main rotor system at the current flapping angle; the third estimation module 400 is used to input multiple flapping positions of one rotor of the helicopter main rotor system and the current pitch control stick length into the twin model, and the twin model calculates the current attitude of the rotating swashplate of the helicopter main rotor system.

[0142] In this embodiment of the application, the first estimation module 200 is further configured to: identify the swing angle, pitch angle and attitude of the rotating swashplate in the current known state; set the corresponding coordinate system of the twin model, and calculate the current pitch lever length based on the corresponding coordinate system, swing angle and pitch angle.

[0143] In this embodiment, the second estimation module 300 is further configured to: obtain the pitch angle coordinate system, flapping coordinate system, and hub coordinate system of the helicopter main rotor system; rotate the pitch angle coordinate system and the flapping coordinate system around the y-axis of the hub coordinate system according to the right-hand rule by the angle corresponding to the flapping angle to obtain a first rotation matrix; rotate the pitch angle coordinate system around the x-axis of its own coordinate system according to the right-hand rule by the angle corresponding to the pitch angle to obtain a second rotation matrix; set a first position of the top coordinate system in the corresponding coordinate system relative to the hub coordinate system, and calculate a first position vector based on the first rotation matrix, the second rotation matrix, and the first position; query the attitude of the rotating swashplate to obtain a second position vector of the bottom coordinate system in the corresponding coordinate system relative to the hub coordinate system, and calculate the current pitch control stick length based on the first position vector and the second position vector.

[0144] In this embodiment of the application, the second estimation module 300 is further configured to: identify the swing angle and the attitude of the swashplate in the current known state; set the corresponding coordinate system of the twin model, and calculate the pitch angle corresponding to the current swing angle based on the corresponding coordinate system, the current pitch lever length, the swing angle and the attitude of the swashplate.

[0145] In this embodiment, the second estimation module 300 is further configured to: acquire the pitch angle coordinate system, flapping coordinate system, and swashplate attitude adjustment coordinate system of the helicopter main rotor system, and identify the translation, roll angle, and pitch angle of the rotating swashplate attitude; translate the swashplate attitude adjustment coordinate system along its own z-axis according to the translation, rotate the swashplate attitude adjustment coordinate system around its own x-axis according to the roll angle, and rotate the swashplate attitude adjustment coordinate system around the y-axis of the swashplate translation coordinate system according to the pitch angle, all according to the right-hand rule; query the third position vector of the top coordinate system relative to the pitch angle coordinate system and the fourth position vector of the bottom coordinate system relative to the flapping coordinate system in the corresponding coordinate system; rotate the pitch angle coordinate system around its own x-axis according to the right-hand rule to obtain the third rotation matrix, and establish the motion constraint equation using the current pitch control rod length; solve the motion constraint equation according to the first position vector, the second position vector, and the third rotation matrix to obtain the pitch angle corresponding to the current flapping angle.

[0146] In this embodiment, the third estimation module 400 is further configured to: set the corresponding coordinate system of the twin model; and calculate the current attitude of the rotating tilt disk based on multiple swing positions, the current pitch lever length, and the corresponding coordinate system.

[0147] In this embodiment, the third estimation module 400 is further configured to: obtain the swashplate attitude coordinate system and the swashplate translation coordinate system of the helicopter main rotor system; based on multiple flapping positions, query the fifth position vector in the corresponding coordinate system relative to the swashplate attitude coordinate system, and the sixth position vector of the top coordinate system in the corresponding coordinate system at each position relative to the swashplate translation coordinate system; establish a function of the rotation matrix under any rotor hub rotation angle, establish the objective function of the nonlinear optimization problem based on the function, the fifth position vector and the sixth position vector, and derive the Jacobian matrix function of the objective function; and perform iterative solution based on the objective function to obtain the attitude of the current rotating swashplate.

[0148] It should be noted that the foregoing explanation of the state estimation method based on the twin model of the helicopter main rotor system also applies to the state estimation device based on the twin model of the helicopter main rotor system in this embodiment, and will not be repeated here.

[0149] The state estimation device based on a twin model of a helicopter main rotor system proposed in this application can perform twin model calculations on parameters such as the pitch control rod length, flapping angle, blade pitch angle, and swashplate attitude to accurately determine the pitch control rod length for subsequent adjustment. It can also calculate the blade pitch angle under any given state for simulated operation of the lift system. By simulating the lifting of the boom based on existing parameters, it replaces manual lifting of the boom itself. Once the upper flapping limit of the boom at a certain position is determined, subsequent measurements do not require lifting it to the upper limit, saving manpower from repeated boom lifting. Accurate calculation of the swashplate attitude based on the blade pitch angle and flapping angle provides a theoretical basis for obtaining different collective and variable pitches. This solves the problems of the inability to directly and accurately measure the pitch control rod length, rotor blade pitch angle, and swashplate attitude, and the high risk and workload associated with manually lifting the boom for adjustment.

[0150] Figure 5 This is a schematic diagram of a helicopter main rotor system provided in an embodiment of this application. The helicopter main rotor system may include:

[0151] The memory 501, the processor 502, and the computer program stored on the memory 501 and capable of running on the processor 502.

[0152] When the processor 502 executes the program, it implements the state estimation method based on the twin model of the helicopter main rotor system provided in the above embodiments.

[0153] Furthermore, the helicopter main rotor system also includes:

[0154] Communication interface 503 is used for communication between memory 501 and processor 502.

[0155] The memory 501 is used to store computer programs that can run on the processor 502.

[0156] The memory 501 may include high-speed RAM (Random Access Memory) memory, and may also include non-volatile memory, such as at least one disk storage.

[0157] If the memory 501, processor 502, and communication interface 503 are implemented independently, then the communication interface 503, memory 501, and processor 502 can be interconnected via a bus to complete communication between them. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 5 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0158] Optionally, in a specific implementation, if the memory 501, processor 502, and communication interface 503 are integrated on a single chip, then the memory 501, processor 502, and communication interface 503 can communicate with each other through an internal interface.

[0159] Processor 502 may be a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement embodiments of this application.

[0160] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the state estimation method based on a twin model of a helicopter main rotor system as described above.

[0161] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0162] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0163] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0164] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (FPGAs), field-programmable gate arrays (FPGAs), etc.

[0165] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

Claims

1. A state estimation method based on a twin model of a helicopter main rotor system, characterized in that, Includes the following steps: Obtain the current known state of the helicopter main rotor system; The current known state is input into the twin model of the helicopter main rotor system, and the twin model calculates the current pitch control rod length of the helicopter main rotor system; Identify the swing angle, paddle pitch angle, and tilting disk attitude of the currently known state; Set the corresponding coordinate system of the twin model, and calculate the current variable pitch lever length based on the corresponding coordinate system, the swing angle, and the pitch angle; Obtain the rotor pitch angle coordinate system, flapping coordinate system, and rotor hub coordinate system of the helicopter main rotor system; Rotate the pitch angle coordinate system and the flapping coordinate system around the y-axis of the hub coordinate system by the angle corresponding to the flapping angle according to the right-hand rule to obtain the first rotation matrix; The pitch angle coordinate system is rotated about the x-axis of its own coordinate system by the right-hand rule, and the angle corresponding to the pitch angle is rotated to obtain the second rotation matrix; Set the first position of the top coordinate system relative to the hub coordinate system in the corresponding coordinate system, and calculate the first position vector based on the first rotation matrix, the second rotation matrix and the first position; Based on the attitude of the rotating tilting disk, the second position vector of the bottom coordinate system relative to the hub coordinate system in the corresponding coordinate system is obtained, and the current pitch rod length is calculated based on the first position vector and the second position vector. The current known state and the current pitch control rod length are input into the twin model, and the twin model calculates the pitch angle of the helicopter main rotor system at the current flapping angle; Identify the swing angle and tilting disk posture of the currently known state; Set the corresponding coordinate system of the twin model, and calculate the corresponding propeller pitch angle under the current swing angle based on the corresponding coordinate system, the current variable pitch rod length, the swing angle and the attitude of the rotating tilt disk; The pitch angle coordinate system, flapping coordinate system, and swashplate attitude adjustment coordinate system of the helicopter main rotor system are obtained, and the translation, roll angle, and pitch angle of the attitude of the rotating swashplate are identified. The tilting disk attitude adjustment coordinate system is translated along its own z-axis according to the translation amount, rotated around its own x-axis according to the roll angle, and rotated around the y-axis of the tilting disk translation coordinate system according to the pitch angle, all according to the right-hand rule. Query the third position vector of the top coordinate system relative to the paddle pitch angle coordinate system in the corresponding coordinate system, and the fourth position vector of the bottom coordinate system relative to the waving coordinate system in the corresponding coordinate system; Rotate the pitch angle coordinate system around the x-axis of its own coordinate system by the angle corresponding to the pitch angle according to the right-hand rule to obtain the third rotation matrix, and establish the motion constraint equation using the condition of the current variable pitch rod length; Solve the motion constraint equations based on the first position vector, the second position vector, and the third rotation matrix to obtain the propeller pitch angle corresponding to the current flapping angle. The twin model inputs multiple flapping positions of one rotor of the helicopter main rotor system and the current pitch control stick length into the twin model, and the twin model calculates the current attitude of the rotating swashplate of the helicopter main rotor system. Set the corresponding coordinate system for the twin model; The attitude of the current rotating tilt disk is calculated based on the multiple swing positions, the current variable pitch lever length, and the corresponding coordinate system; Obtain the swashplate attitude control coordinate system and the swashplate translation coordinate system of the helicopter main rotor system; Based on the multiple waving positions, query the fifth position vector in the corresponding coordinate system relative to the tilting disk attitude adjustment coordinate system, and the sixth position vector of the top coordinate system in the corresponding coordinate system at each position in the tilting disk translation coordinate system; A function for establishing the rotation matrix under arbitrary hub rotation angle is established. Based on the function, the fifth position vector, and the sixth position vector, an objective function for the nonlinear optimization problem is established, and the Jacobian matrix function of the objective function is derived. The attitude of the current rotating tilt disk is obtained by iteratively solving the objective function.

2. A state estimation device based on a twin model of a helicopter main rotor system, characterized in that, The method for performing the state estimation based on a twin model of a helicopter main rotor system as described in claim 1 includes: The acquisition module is used to acquire the current known state of the helicopter main rotor system; The first estimation module is used to input the current known state into the twin model of the helicopter main rotor system, and the twin model calculates the current pitch control rod length of the helicopter main rotor system. The second estimation module is used to input the current known state and the current pitch control rod length into the twin model, and the twin model calculates the pitch angle of the helicopter main rotor system at the current flapping angle; The third estimation module is used to input multiple flapping positions of one rotor of the helicopter main rotor system and the current pitch control stick length into the twin model, and the twin model calculates the current attitude of the rotating swashplate of the helicopter main rotor system.

3. A helicopter main rotor system, characterized in that, include: The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the state estimation method based on a twin model of a helicopter main rotor system as described in claim 1.

4. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the state estimation method based on the twin model of the helicopter main rotor system as described in claim 1.

Images