Multi-degree-of-freedom wind power test composite loading control method, system, medium and product

Abstract

The present application relates to the technical field of electromechanical hydraulic servo control and loading test, and discloses a multi-degree-of-freedom wind power test composite loading control method, system, medium and product, the method comprising: obtaining a target load spectrum; obtaining the pose information of a loader; calculating the instantaneous load of the LAC point based on the mathematical model under the non-inductive observer and the force given value of the hydraulic actuator; obtaining the error based on the non-torque target load spectrum and the instantaneous load of the LAC point; judging, if the condition is met, then the iteration is ended, and the force given value of the hydraulic actuator is output. The control method comprises: first, obtaining the target load and the pose information, then calculating the instantaneous load of the LAC point based on the mathematical model under the non-inductive observer and the force given value of the hydraulic actuator, and actively processing the strong coupling, nonlinearity and motion hysteresis of the parallel loader based on the Newton iteration feedforward compensation of model pre-control, which has faster dynamic response and higher steady-state loading accuracy than the traditional closed-loop control.

Description

Technical Field

[0001] This invention relates to the field of electromechanical-hydraulic servo control and loading test technology, and in particular to a multi-degree-of-freedom wind power testing composite loading control method, system, medium and product. Background Technology

[0002] During actual operation, the main drive train of a wind turbine is constantly subjected to a dynamically unbalanced load environment due to complex meteorological factors such as random wind fields, wind shear, and tower shadow effects. These loads can be physically decomposed into wind torque loads along the main shaft axis and non-torque loads acting on the rotor's plane of rotation. The non-torque loads further manifest as flapping loads perpendicular to the plane of rotation and yaw loads parallel to the plane of rotation, ultimately transmitted through the hub as six-degree-of-freedom load components (i.e., forces acting in three directions) with different amplitudes and phases in the spatial coordinate system. , , Torque in three directions , , Therefore, to accurately reproduce the operating state of wind turbines in a ground-based laboratory, it is necessary to achieve precise decoupling and synchronous loading of the aforementioned six-degree-of-freedom composite loads.

[0003] To effectively reproduce the six-degree-of-freedom load of the main drive train, both electric motor-driven and electro-hydraulic loading methods can be employed. The electric motor drives the drive train to rotate, reproducing the wind torque load, while the outputs of the individual electro-hydraulic actuators are combined to reproduce the remaining five-degree-of-freedom load. Thus, through the combined action of the electric motor and electro-hydraulic actuators, the various static and dynamic loads experienced by the main drive train under different operating conditions can be reproduced relatively comprehensively, accurately reflecting the load state of the wind turbine under various operating conditions, facilitating future load testing and performance evaluation. However, in current engineering practice, the decoupling control of multi-degree-of-freedom loading systems faces three major technical challenges, as follows: (1) Complexity and redundancy of pose solution: In order to obtain the accurate pose of the load application center (LAC) in space, the system is usually configured with multiple displacement, tilt and force measurement sensors, forming a redundant multi-input multi-output system. How to efficiently and in real time fuse these sensor data to obtain a real-time and high-precision pose solution is the prerequisite for the accurate loading control of the system.

[0004] (2) Difficulties in load sensing: Directly installing six-component force sensors at the loading point for "sensory observation" faces challenges such as calibration difficulties, severe multi-axis coupling, high costs, and insufficient long-term stability. Therefore, exploring a "sensory observation" method that does not rely on physical sensors at the LAC point but indirectly calculates the load using existing sensors in the system has significant engineering practical value.

[0005] (3) Strong coupling and nonlinear control of the system: The output force of each actuator to the loading point is coupled with nonlinear factors such as transmission chain gap, making the direct closed-loop control from the load setpoint to the displacement / force output extremely unstable. Traditional PID control is difficult to solve the dynamic control problem of this tightly coupled, nonlinear MIMO (Multi-Input Multi-Output) system.

[0006] In summary, it is necessary to provide a new multi-degree-of-freedom wind power testing composite loading control method to solve the above-mentioned technical problems. Summary of the Invention

[0007] The main objective of this invention is to provide a multi-degree-of-freedom wind power testing composite loading control method. This method utilizes redundant sensors to fuse pose analysis as the kinematic basis, establishes a sensorless load observer as the sensing core, and designs an iterative feedforward compensation control strategy based on model pre-control to achieve spatial decoupling of the multi-degree-of-freedom load and real-time reproduction of the dynamic load spectrum. The specific technical solution is as follows: A multi-degree-of-freedom wind power testing composite loading control method, the control method includes the following steps: Step 1: Real-time simulation, specifically including: establishing a simulation model; generating a real-time six-degree-of-freedom load spectrum for the wind turbine based on the simulation model and setting the non-torque target load spectrum. ; Step 2, Data Acquisition, specifically includes: acquiring raw data; generating the real-time pose of the loader based on the raw data; Step 3: Obtain the initial setpoint, which specifically includes: calculating the force setpoint of the hydraulic actuator based on the inverse Jacobian matrix and the non-torque target load spectrum obtained in Step 1; Step 4: Calculate the force setpoint of the hydraulic actuator based on the mathematical model under the sensorless observer. Instantaneous load at LAC point of step , Take a natural number greater than or equal to 1; Step 5: Make a judgment, specifically based on the non-torque target load spectrum obtained in Step 1. and the Instantaneous load at LAC point of step Obtaining error : ; Determine whether any of the following termination conditions are met: ① The absolute error is less than the allowable tolerance: ,in: The convergence accuracy is preset. ② The number of iterations exceeds the maximum allowed number. >N, where N is the maximum number of iterations; If neither of the two conditions is met, then the first step is calculated using the Lijacobi pseudo-inverse matrix at the current time. Incremental force compensation for each hydraulic actuator ,in: For the first The inverse Jacobian matrix of the step; let = +1, return to step four; If any condition is met, the iteration ends and the output force value of the hydraulic actuator is output.

[0008] Preferably, the raw data in step two includes time step, loading module, operating conditions, wind speed, wind direction, turbulence intensity, blade parameters, wind turbine parameters, material properties, and wind turbine control strategy.

[0009] Preferred, the first The force setpoint of a hydraulic actuator is expressed by the following formula: ; ; in: Let be the force Jacobian matrix from the hydraulic actuator to the LAC point, determined by the pose.

[0010] Preferably, the mathematical model under the sensorless observer in step four is expressed as follows: ; in: This is a compensation term for the gravity effect of the loader; This is a compensation term for the effects of the loader's motion inertia and acceleration.

[0011] Preferably, the gravity effect compensation term of the loader Expressed as follows: ; in: , , Indicates loader along , , The component values ​​of the axis; , , The coordinates of the loader's center of gravity; Compensation term for the effects of moment of inertia and acceleration Expressed as follows: ; in: For the quality of the loader; Let the moment of inertia of the loader be denoted as 'Mo'. The pose information of the loader's center of gravity. The linear velocity and angular velocity of the loader's center of gravity are Obtained through numerical differentiation. The linear and angular accelerations of the loader's center of gravity are... Obtained through numerical differentiation; subscript , , Edge , , The component values ​​of the axis.

[0012] Preferably, the gravity effect compensation term of the loader The equivalent pose is calculated, and obtaining the equivalent pose includes the following steps: The virtual pose of the loader is solved in real time using forward kinematics of the mechanism. ; The measured pose data of the loader are obtained by adaptive weighted fusion of multiple sets of measured pose data using principal component analysis. ; Loader-based virtual pose And the measured pose data of the loader Obtain the equivalent pose Specifically: ; in: For virtual pose The mean squared error; For actual attitude measurement The mean squared error.

[0013] The advantages of applying the technical solution of this invention are as follows: The control method of this invention includes: first acquiring the target load, then acquiring the initial setpoint, then calculating the instantaneous load at the LAC point based on the mathematical model under the sensorless observer and the force setpoint of the hydraulic actuator; and actively handling the strong coupling, nonlinearity, and motion hysteresis of the parallel loaders based on the Newton iterative feedforward compensation of the model pre-control, which has a faster dynamic response and higher steady-state loading accuracy than traditional closed-loop control. It eliminates the need to install expensive six-component load measurement sensors at the test end, and achieves high-precision load identification using only the existing sensors in the system, which significantly reduces hardware costs and maintenance difficulty, and improves system reliability. Through the multi-sensor fusion strategy, it overcomes the problems of limited accuracy and susceptibility to interference of single sensors, and provides an accurate kinematic basis for motion control and load identification.

[0014] The present invention also discloses a multi-degree-of-freedom wind power test composite loading control system, including a drive motor, a coupling, a loading cylinder, a loading bracket, a wind turbine under test, a hydraulic actuator group, and a sensor group; The drive motor is rotatably connected to the drive end of the loading cylinder via a coupling; The driving end and the test end of the loading cylinder are respectively provided with loading brackets; loading connecting rods are respectively provided on the two sets of loading brackets; The tested blower is connected to the tested end of the loading cylinder; The hydraulic actuator assembly includes a first vertical hydraulic actuator unit, a second vertical hydraulic actuator unit, and a horizontal hydraulic actuator unit. The first vertical hydraulic actuator unit includes two vertical hydraulic actuators symmetrically arranged at the drive end. The second vertical hydraulic actuator unit includes two vertical hydraulic actuators symmetrically arranged at the test end. The horizontal hydraulic actuator unit includes two horizontal hydraulic actuators symmetrically arranged on both sides of the loading cylinder. The sensor group includes: force sensors and displacement sensors installed on the top of the hydraulic cylinders in the six hydraulic actuators, used to obtain the force value output by the hydraulic cylinder and the length change value of the hydraulic cylinder; tilt sensors installed on the hydraulic rod, the loading bracket at the drive end, the loading link at the drive end, the loading bracket at the test end, and the loading link at the test end of the hydraulic actuator, used to obtain real-time pose data; and torque sensors installed on the coupling, used to obtain the output torque value of the drive motor.

[0015] The present invention also discloses a control system for a multi-degree-of-freedom loading device, the control system comprising: One or more processors; Storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the multi-degree-of-freedom wind power test composite loading control method as described above.

[0016] The present invention also discloses a computer-readable storage medium storing a computer program that, when executed by a processor, implements the multi-degree-of-freedom wind power test composite loading control method as described above.

[0017] The present invention also discloses a computer program product, including a computer program that, when executed by a processor, implements the multi-degree-of-freedom wind power test composite loading control method as described above. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of the multi-degree-of-freedom wind power test bench composite loading system in Embodiment 1 of the present invention; Figure 2 for Figure 1 Middle left view; Figure 3 This refers to the real-time torque in the X-axis direction at a 50ms interval at the loading point of the wind turbine in Embodiment 1 of the present invention. Figure 4 This refers to the real-time bending moment in the Y-axis direction at a 50ms interval at the loading point of the wind turbine in Embodiment 1 of the present invention. Figure 5 This refers to the real-time bending moment in the Z-axis direction at a 50ms interval at the loading point of the wind turbine in Embodiment 1 of the present invention. Figure 6 This refers to the real-time force value in the X-axis direction at a 50ms interval at the loading point of the wind turbine in Embodiment 1 of the present invention. Figure 7 This refers to the real-time force value in the Y-axis direction at a 50ms interval at the loading point of the wind turbine in Embodiment 1 of the present invention. Figure 8 The real-time force value in the Z-axis direction at a 50ms interval at the loading point of the wind turbine in Embodiment 1 of the present invention; Figure 9 This is a flowchart of the multi-degree-of-freedom wind power testing composite loading control method in Embodiment 1 of the present invention; Figure 10 This is a flowchart of the virtual pose output iteration process of the loader in Embodiment 1 of the present invention; Figure 11 This is an iterative flowchart of the output force value of the hydraulic cylinder in Embodiment 1 of the present invention; The components include: 1. drive motor; 2. coupling; 3. loading cylinder; 4. loading bracket; 5. tested fan; 6. vertical hydraulic actuator; 7. horizontal hydraulic actuator; and 8. loading linkage.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1: A multi-degree-of-freedom wind power test bench composite loading system, see details. Figures 1-2 It includes a drive motor 1, a coupling 2, a loading cylinder 3, a loading bracket 4, a tested fan 5, a hydraulic actuator group, and a sensor group; The drive motor 1 is rotatably connected to the drive end of the loading cylinder 3 via a coupling 2. The driving end and the test end of the loading cylinder 3 are respectively provided with loading brackets 4; the two sets of loading brackets 4 are respectively provided with loading connecting rods 8; The tested fan 5 is connected to the tested end of the loading cylinder 3; The hydraulic actuator assembly includes a first vertical hydraulic actuator unit, a second vertical hydraulic actuator unit, and a horizontal hydraulic actuator unit. The first vertical hydraulic actuator unit includes two vertical hydraulic actuators 6 symmetrically arranged at the drive end. The second vertical hydraulic actuator unit includes two vertical hydraulic actuators symmetrically arranged at the test end. The horizontal hydraulic actuator unit includes two horizontal hydraulic actuators 7 symmetrically arranged on both sides of the loading cylinder 3. The sensor group includes: force sensors and displacement sensors installed on the top of the hydraulic cylinders in the six hydraulic actuators, used to obtain the force value output by the hydraulic cylinder and the length change value of the hydraulic cylinder; tilt sensors installed on the hydraulic rod, the loading bracket at the drive end, the loading link at the drive end, the loading bracket at the test end, and the loading link at the test end of the hydraulic actuator, used to obtain real-time pose data; and torque sensors installed on the coupling, used to obtain the output torque value of the drive motor.

[0023] Specifically, 4 Two vertical hydraulic actuators are arranged in a directional manner. The horizontal hydraulic actuator is arranged in a direction, with the loading center point (LAC point) being the center point of the fan under test.

[0024] , The vertical hydraulic actuator force at the drive end, , The vertical hydraulic actuator force at the test end. , The force applied by the horizontal hydraulic actuator, To apply the weight of the loading cylinder and support loader, , , For the loader's center of gravity position along , , Components of the axis, The length of the loading arm of the hydraulic actuator at the test end. The length of the hydraulic actuator at the test end from the loading point LAC ( =3, 4), The length of the loading arm of the hydraulic actuator at the drive end. The distance between the hydraulic actuator at the drive end and the loading point LAC ( =1, 2), This refers to the extension / retraction length of the hydraulic actuator. For the first The extension length of a hydraulic actuator ( =1, 2, 3, 4, 5, 6), The distance between the center of the loading axis and the horizontal loading link. This refers to the effective radius of the vertical hydraulic actuator.

[0025] Loading tests were conducted using the aforementioned multi-degree-of-freedom wind power test bench composite loading system. For detailed control methods, please refer to [link to relevant documentation]. Figure 9 This includes: a wind field model and a real-time aerodynamic simulation model of the blades to obtain a real-time load spectrum; torque loads are input to the spindle servo driver, which drives the spindle motor to move the multi-degree-of-freedom test bench, and real-time torque is fed back to the spindle servo driver; non-torque loads and displacement / attitude are fed back to a multi-dimensional Newton iterative solver for calculation to obtain the actuator target force, which is input to the hydraulic servo controller to drive the hydraulic actuator to move the multi-degree-of-freedom test bench. Details are as follows: The loading test includes the following steps: Step 1: Real-time simulation, specifically including: establishing a simulation model; generating a real-time six-degree-of-freedom load spectrum for the wind turbine based on the simulation model and setting the non-torque target load spectrum. ; Step 2, Data Acquisition, specifically includes: acquiring raw data; generating the real-time pose of the loader based on the raw data; Step 3: Obtain the initial setpoint, which specifically includes: calculating the force setpoint of the hydraulic actuator based on the inverse Jacobian matrix and the non-torque target load spectrum obtained in Step 1; Step 4: Calculate the force setpoint of the hydraulic actuator based on the mathematical model under the sensorless observer. Instantaneous load at LAC point of step , Take a natural number greater than or equal to 1; Step 5: Make a judgment, specifically based on the non-torque target load spectrum obtained in Step 1. and the Instantaneous load at LAC point of step Obtaining error : ; Determine whether any of the following termination conditions are met: ① The absolute error is less than the allowable tolerance: ,in: The convergence accuracy is preset. ② The number of iterations exceeds the maximum allowed number: >N, where N is the maximum number of iterations; If neither of the two conditions is met, then the first step is calculated using the Lijacobi pseudo-inverse matrix at the current time. Incremental force compensation for each hydraulic actuator ,in: For the first The inverse Jacobian matrix of the step; let = +1, return to step four; If any condition is met, the iteration ends and the output force value of the hydraulic actuator is output.

[0026] Details are as follows: The first real-time simulation layer consists of a high-fidelity simulation model running on a real-time simulator. This model integrates a three-dimensional turbulent wind field and a blade aero-elastic coupled dynamics model (using existing technology), and can solve and output the real-time load spectrum acting on the wind turbine loading point in real time with a fixed step size in milliseconds. It can be decomposed into torque. Non-torque load spectrum (i.e., the target load spectrum) provides the system with a precise feedforward command source.

[0027] The specific implementation logic is as follows: The dynamics real-time simulation platform is built upon ConcurrentReal-Time's hardware real-time simulator and the open-source wind turbine simulation software OpenFast. At the hardware level, ConcurrentReal-Time provides a robust real-time hardware platform and simulation testing software, providing a real-time operating environment for OpenFast. At the software level, OpenFast allows the creation of a multibody dynamics model of the wind turbine. Combined with its internal wind field simulation and aerodynamics modules, and based on user-input simulation parameters such as time step, loading modules, operating conditions, wind speed, wind direction, turbulence intensity, blade parameters, turbine parameters, material properties, and turbine control strategies, it generates a real-time load spectrum for the wind turbine.

[0028] Software version: OpenFast v4.2.1 Simulation runtime (TMax): 700s, module time step (DT): 0.005s, output time step (DT_Out): 0.01s Load modules: Select CompElast (structural dynamics), CompInflow (incoming air velocity), CompAreo (aerodynamics), and CompServo (control and electro-drive dynamics). Wind turbine power: 20MW; Operating conditions: ① Wind speed range: 3m / s-25m / s, rated wind speed: 10.5m / s; ② Wind direction: due north; ③ Turbulence intensity (Iref): 0.14; ④ Blade parameters are shown in Table 1; ⑤ Turbine parameters are shown in Table 2; ⑥ Material properties: Blades are made of composite materials, and the main load-bearing beam is made of high-modulus glass fiber / carbon fiber hybrid; longitudinal elastic modulus 45GPa, transverse elastic modulus 12GPa, shear modulus 5GPa, density 1900kg / m³ 3 ⑦ Tower: S355 structural steel, elastic modulus 210 GPa, shear modulus 80.8 GPa, density 7850 kg / m³ 3 Yield strength 355MPa; ⑧. Hub: Cast iron, elastic modulus 175GPa, density 7200kg / m³ 3 ⑨ Cabin: High-strength aluminum alloy, elastic modulus 80 GPa, density 2810 kg / m³ 3 ⑩. Wind turbine control strategy: variable speed and pitch control, see details. Figures 3-8 This indicates a 50ms interval at the wind turbine's loading point. , , Real-time torque (bending moment) and force value in the axial direction.

[0029] Table 1 Blade Parameters

[0030] Table 2 Fan Parameters

[0031] The second layer is the attitude analysis layer, which collects real-time data from tilt sensors and displacement sensors on six hydraulic actuators, as well as a set of tilt sensors mounted on the loading link and loading bracket at the drive end and the loading link and loading bracket at the test end. The displacement sensors obtain the real-time length values ​​of the six hydraulic cylinders, and the tilt sensors acquire the linear acceleration, angular velocity, and angle of each component. Velocity is obtained by integrating the linear acceleration, and displacement is obtained by integrating it again. Angle is obtained by integrating the angular velocity. This yields the set of pose parameters for the hydraulic cylinders, loading bracket, and loading link. Define pose ,in: For displacement, along , , Displacement of axis , , , For the angle of inclination, and , , Angle between axes ; This represents the number of tilt sensor locations. =1-10), serving as parameter inputs for the load calculation layer. These multiple sensor sets constitute a system with redundant design, employing weighted averaging or multi-source Kalman filters for noise suppression and data fusion to output a more accurate real-time pose set.

[0032] The specific implementation logic is as follows: Step 1: Using six hydraulic actuator displacement sensors, the six-DOF virtual pose of the loader is solved in real time through the forward kinematics of the mechanism, as follows: The correct kinematic solution of the mechanism is obtained through the lengths of the six hydraulic cylinders. ( Solve for the loader's virtual pose using the numbers 1, 2, 3, 4, 5, and 6. .

[0033] Define the base connected to the ground as a static coordinate system. The coordinates of the hinge points connecting the six hydraulic cylinders to the base are: Define the center of the loader as a moving coordinate system. The coordinates of the hinge points connecting the six hydraulic cylinders to the base are: Define the attitude deflection of the motion coordinate system. , looking up and roll They are respectively: ; Then according to , , (External rotation) rotation sequence, total rotation matrix for: ; Where: the displacement of the moving coordinate system is The attitudes of the motion coordinate system are deflection. , looking up and roll Then the first The coordinates of the hinge point connecting the hydraulic cylinder and the base in the static coordinate system for: ; Then the first The length of each hydraulic cylinder is: ; Construct a system of equations: ; Because the above equations are highly nonlinear, Newton's numerical iteration method is used to solve them, and the hydraulic cylinder length error vector is defined as: ; in: For the first Calculated length of each hydraulic cylinder For the first The target length of each hydraulic cylinder.

[0034] Jacobian matrix ; The sensitivity of hydraulic cylinder length to pose is described. Definition by the first Hydraulic cylinder alignment posture No. The partial derivatives for each degree of freedom are calculated as follows: ; in: It represents a small perturbation.

[0035] Define the pose correction as: ; in: Jacobian matrix The inverse matrix.

[0036] For details of the iterative process, please refer to Figure 10 The steps are as follows: Step ①: Input the target length of the hydraulic cylinder, i.e., the currently measured length of the hydraulic cylinder. ; Step 2: Set the maximum number of iterations N=50, and the error tolerance. Small perturbation amount =0.01, initial pose Take the pose from the previous moment; if there is no historical value, start from the pre-calibrated zero position. Step 3: Calculate the actual length of the hydraulic cylinder in the current pose based on the initial pose, and then calculate the error between the actual length of the hydraulic cylinder and the target hydraulic cylinder length. ; Step 4: Determine the error Or the number of iterations If the above conditions are not met, calculate the Jacobian matrix and its inverse matrix, and then calculate the pose correction. Update the pose for the next iteration. Return to step ③; if satisfied, output the virtual pose of the loader. .

[0037] Step 2: The measured pose data from the hydraulic cylinder, loading bracket, and loading linkage are adaptively weighted and fused using principal component analysis to obtain the measured pose number. Details are as follows: There are six sets of pose information on the six hydraulic cylinders, two sets of pose information on the loading brackets at the drive and test ends, and two sets of pose information on the loading linkages at the drive and test ends, totaling ten sets of pose information. Principal component analysis is used to adaptively weight and fuse multiple sets of measured pose data to obtain the number of measured poses. The specific steps are as follows: make , For the pose information matrix of the loader, the matrix is... Perform principal component analysis: First, analyze the matrix... The matrix is ​​obtained by standardizing to zero mean and unit variance. ,in , For matrix No. The first position of the pose Item data, For the first The mean of the indicators, For the first The variance of each indicator is calculated, followed by the calculation of the covariance matrix. Calculate the matrix Eigenvalues and eigenvectors ,in Select the eigenvector corresponding to the principal component with the largest variance contribution rate. .

[0038] Define the overall support level of each group of pose information as follows: ; The measured pose data of the loader are as follows: .

[0039] Step 3: Use Kalman filtering to fuse the virtual pose and the measured pose to obtain the equivalent pose, as detailed below: Parallel computation of virtual poses at the same time and measured attitude And calculate the virtual pose in real time by combining historical data. mean square deviation and measured attitude mean square deviation The equivalent pose of the loader is calculated by fusing the virtual pose and the measured pose using Kalman filtering. ,as follows: .

[0040] The third layer is the load calculation layer, whose core task is to solve the inherent strong nonlinear coupling problem when six hydraulic actuators apply push-pull forces together. First, a real-time non-torque load sensing module based on a sensorless observer is constructed. Without direct measurement equipment at the test end, the module relies entirely on the force sensors installed on each actuator, the pose and motion parameters output by the pose analysis module, and the system's dynamic model to calculate the non-torque five-degree-of-freedom load at the loading point in real time. (force and bending moment ).

[0041] The mathematical model of the insensible load observer can be expressed as: ; in: The force Jacobian matrix from the actuator to the LAC point, determined by the pose, is mainly calculated from the pose information of the six hydraulic cylinders. The gravity effect compensation term for the loader and actuator is mainly calculated based on the equivalent pose; This is a compensation term for the effects of inertia and acceleration, mainly calculated based on the equivalent pose. The linear velocity and angular velocity of the equivalent pose are Obtained through numerical differentiation. The linear and angular accelerations of the equivalent pose are It is obtained through numerical differentiation.

[0042] The specific calculation process is as follows: Based on the spatial force and torque balance relationship of the loading device, we have: ; ; ; ; ; in: for The output force of the first hydraulic actuator, with thrust being positive and pull being negative, is obtained by the force sensor on the hydraulic cylinder. Indicates the first Hydraulic cylinder edge , , Component values ​​of shaft output force ; For the quality of the loader; Indicates loader along , , The component values ​​of the axis; Let the moment of inertia of the loader be , Indicates loader wrap , , Moment of inertia of the shaft; The pose information of the loader's center of gravity. The linear velocity and angular velocity of the loader's center of gravity are Obtained through numerical differentiation. The linear and angular accelerations of the loader's center of gravity are... It is obtained through numerical differentiation.

[0043] The calculation formula is as follows:

[0044] The calculation formula is as follows: ; The calculation formula is as follows: ; Based on the instantaneous load calculated above .

[0045] Design an online solver based on the model-predictive multidimensional Newton-Raphson iterative method. This solver calculates the Jacobian matrix in real-time within each control cycle based on the geometric relationship between actuator displacement and attitude obtained from real-time feedback. , , And solve the equation quickly using an iterative algorithm. .

[0046] The above equations are nonlinear and require Newton's iterative algorithm to solve. See details... Figure 11 The specific calculation process is as follows: Step 1: Parameter initialization, setting the target load. Set the load tolerance ε (=1.0e-4) and the maximum number of iterations N (N=50).

[0047] Step ②: Calculation of initial given values. Without considering dynamic compensation for pose, gravity, and inertia, the calculation is based on the inverse Jacobian matrix. (Since the Jacobian matrix is ​​not a square matrix, the inverse matrix cannot be obtained directly. It is solved using the Moore-Penrose pseudo-inverse method based on the minimum norm and least squares solution.) Calculate the initial force setpoint for each actuator. ( =1, 2, 3, 4, 5, 6), Let represent the inverse Jacobian matrix of the initial iteration; Step ③, Multi-step iterative motion / pose compensation: Using the current pose, motion parameters, and the force of the actuator in the current step ( =1, 2, 3, 4, 5, 6), this force can be measured by the force sensor on each actuator, and substituted into the mathematical model under the sensorless observer to calculate the instantaneous load at the LAC point in the current step. ; Calculate the error with respect to the target load. ; Convergence criterion, specifically: whether any of the following termination conditions are met: ① Absolute error is less than the allowable tolerance: ,in ① The convergence accuracy is predetermined; ② The number of iterations exceeds the maximum allowed number: >N.

[0048] If neither of the two conditions is met, then let = +1, calculate the actuator force compensation increment using the current force Jacobian pseudo-inverse matrix. ( =1, 2, 3, 4, 5, 6), update the given... ( =1, 2, 3, 4, 5, 6), and calculate the output force value of the hydraulic cylinder for each of the following moments. It is sent to the hydraulic servo controller and continues the next round of iteration updates until the target load is reached.

[0049] The iteration ends if any of the conditions are met. This occurs when the absolute error is less than the allowable tolerance. At that time, the output force of the hydraulic cylinder stabilizes at the current moment. ( =1, 2, 3, 4, 5, 6). When the number of iterations exceeds the maximum allowed number, an iteration non-convergence warning is issued, and a backup strategy is used: the current time step is... ( Using the initial values ​​(1, 2, 3, 4, 5, 6) as the iterative values, the iteration calculation is performed again. If the iteration calculation still fails, a tolerance will be allowed. The value is increased to 10 times the original value, which will reduce the failure rate of the previous iteration. ( =1, 2, 3, 4, 5, 6) are used as initial values ​​for iterative calculation. If the iterative calculation still fails, the average of the three iterative values ​​is calculated as the final output value of the hydraulic cylinder.

[0050] The fourth layer is the high-dynamic execution layer, responsible for precise tracking of each control command. For the torque channel, disturbance correction is achieved using feedback based on the torque sensor. When the load increases, the torque sensor measurement will suddenly increase, triggering a command to the motor spindle servo controller to reduce the motor speed and increase the torque output of the drive motor to match changes in the external load, thus forming a closed-loop control of the torque load. For the non-torque channel, the target load from the real-time simulation layer is used as a feedforward force command and sent to the load calculation layer. Based on the pose data obtained from the attitude analysis layer, the hydraulic cylinder output value that meets the dynamic load requirements is iteratively calculated in real time. Finally, the output values ​​of each hydraulic cylinder are sent to the hydraulic servo controller, achieving iterative decoupling of the non-torque load on the hydraulic cylinder. Through separate control of torque and non-torque loads, the drive motor and loader execute with high dynamic response, thereby accurately reproducing the wind energy load spectrum. The entire system’s four-layer architecture is tightly coupled through deterministic real-time Ethernet (such as EtherCAT) and synchronized by a unified global clock to ensure strict alignment of simulation, calculation and control cycles. It also integrates multiple real-time safety monitoring for load tracking error, actuator status and algorithm convergence, together forming a six-degree-of-freedom loading control system capable of coping with the challenges of strong nonlinearity and strong coupling.

[0051] The technical solution applied in this embodiment is as follows: 1. It eliminates the need to install expensive six-component load measurement sensors on the test subject, and achieves high-precision load identification using only the existing sensors in the system, which significantly reduces hardware costs and maintenance difficulty, and improves system reliability.

[0052] 2. By employing a multi-sensor fusion strategy, the limitations of single sensors in terms of accuracy and susceptibility to interference are overcome, providing a precise kinematic basis for motion control and load identification.

[0053] 3. Based on model-driven Newton iterative feedforward compensation, it actively addresses the strong coupling, nonlinearity, and motion hysteresis of parallel loaders, resulting in faster dynamic response and higher steady-state loading accuracy compared to traditional closed-loop control.

[0054] Example 2: This embodiment provides a control system for a multi-degree-of-freedom loading device, including: One or more processors; Storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the multi-degree-of-freedom wind power test composite loading control method as described above.

[0055] Example 3: This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the multi-degree-of-freedom wind power testing composite loading control method described above.

[0056] Example 4: This embodiment provides a computer program product, including a computer program that, when executed by a processor, implements the multi-degree-of-freedom wind power testing composite loading control method as described above.

[0057] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A multi-degree-of-freedom wind power testing composite loading control method, characterized in that, The control method includes the following steps: Step 1: Real-time simulation, specifically including: establishing a simulation model; generating a real-time six-degree-of-freedom load spectrum for the wind turbine based on the simulation model and setting the non-torque target load spectrum. ; Step 2, Data Acquisition, specifically includes: acquiring raw data; generating the real-time pose of the loader based on the raw data; Step 3: Obtain the initial setpoint, which specifically includes: calculating the force setpoint of the hydraulic actuator based on the inverse Jacobian matrix and the non-torque target load spectrum obtained in Step 1; Step 4: Calculate the force setpoint of the hydraulic actuator based on the mathematical model under the sensorless observer. Instantaneous load at LAC point of step , Take a natural number greater than or equal to 1; Step 5: Make a judgment, specifically based on the non-torque target load spectrum obtained in Step 1. and the Instantaneous load at LAC point of step Obtaining error : ； Determine whether any of the following termination conditions are met: ① The absolute error is less than the allowable tolerance: ,in: The convergence accuracy is preset. ② The number of iterations exceeds the maximum allowed number: >N, where N is the maximum number of iterations; If neither of the two conditions is met, then the first step is calculated using the Lijacobi pseudo-inverse matrix at the current time. Incremental force compensation for each hydraulic actuator ,in: For the first The inverse Jacobian matrix of the step; let = +1, return to step four; If any condition is met, the iteration ends and the output force value of the hydraulic actuator is output.

2. The multi-degree-of-freedom wind power testing composite loading control method according to claim 1, characterized in that, The raw data in step two includes time step, loading module, operating conditions, wind speed, wind direction, turbulence intensity, blade parameters, turbine parameters, material properties, and turbine control strategy.

3. The multi-degree-of-freedom wind power testing composite loading control method according to claim 1, characterized in that, No. The force setpoint of a hydraulic actuator is expressed by the following formula: ; ； in: Let be the force Jacobian matrix from the hydraulic actuator to the LAC point, determined by the pose.

4. The multi-degree-of-freedom wind power testing composite loading control method according to claim 3, characterized in that, The mathematical model under the sensorless observer in step four is expressed as follows: ； in: This is a compensation term for the gravity effect of the loader; This is a compensation term for the effects of the loader's motion inertia and acceleration.

5. The multi-degree-of-freedom wind power testing composite loading control method according to claim 4, characterized in that, Gravity effect compensation term for loader It can be expressed as follows: ； in: , , Indicates loader along , , The component values ​​of the axis; , , The coordinates of the loader's center of gravity; Compensation term for the effects of moment of inertia and acceleration It can be expressed as follows: ； in: For the quality of the loader; Let the moment of inertia of the loader be denoted as 'Mo'. The pose information of the loader's center of gravity. The linear velocity and angular velocity of the loader's center of gravity are Obtained through numerical differentiation. The linear and angular accelerations of the loader's center of gravity are... Obtained through numerical differentiation; subscript , , Edge , , The component values ​​of the axis.

6. The multi-degree-of-freedom wind power testing composite loading control method according to claim 5, characterized in that, Gravity effect compensation term for loader The equivalent pose is calculated, and obtaining the equivalent pose includes the following steps: The virtual pose of the loader is solved in real time using forward kinematics of the mechanism. ; The measured pose data of the loader are obtained by adaptive weighted fusion of multiple sets of measured pose data using principal component analysis. ; Loader-based virtual pose And the measured pose data of the loader Obtain the equivalent pose Specifically: ； in: For virtual pose The mean squared error; For actual attitude measurement The mean squared error.

7. A multi-degree-of-freedom wind power testing composite loading control system, characterized in that, It includes a drive motor (1), a coupling (2), a loading cylinder (3), a loading bracket (4), a tested fan (5), a hydraulic actuator assembly, and a sensor assembly; The drive motor (1) is rotatably connected to the drive end of the loading cylinder (3) via a coupling (2); The driving end and the test end of the loading cylinder (3) are respectively provided with loading brackets (4); the two sets of loading brackets (4) are respectively provided with loading connecting rods (8); The tested fan (5) is connected to the tested end of the loading cylinder (3); The hydraulic actuator assembly includes a first vertical hydraulic actuator unit, a second vertical hydraulic actuator unit, and a horizontal hydraulic actuator unit. The first vertical hydraulic actuator unit includes two vertical hydraulic actuators (6) symmetrically arranged at the drive end. The second vertical hydraulic actuator unit includes two vertical hydraulic actuators symmetrically arranged at the test end. The horizontal hydraulic actuator unit includes two horizontal hydraulic actuators (7) symmetrically arranged on both sides of the loading cylinder (3). The sensor group includes: force sensors and displacement sensors installed on the top of the hydraulic cylinders in the six hydraulic actuators, used to obtain the force value output by the hydraulic cylinder and the length change value of the hydraulic cylinder; tilt sensors installed on the hydraulic rod, the loading bracket at the drive end, the loading link at the drive end, the loading bracket at the test end, and the loading link at the test end of the hydraulic actuator, used to obtain real-time pose data; and torque sensors installed on the coupling, used to obtain the output torque value of the drive motor.

8. A multi-degree-of-freedom wind power testing composite loading control system, characterized in that, include: One or more processors; Storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the multi-degree-of-freedom wind power testing composite loading control method as described in any one of claims 1-6.

9. A computer-readable storage medium storing a computer program, characterized in that, When executed by the processor, the program implements the multi-degree-of-freedom wind power testing composite loading control method as described in any one of claims 1-6.

10. A computer program product, characterized in that, It includes a computer program that, when executed by a processor, implements the multi-degree-of-freedom wind power testing composite loading control method as described in any one of claims 1-6.

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