Wide-range wind shear generation system, parameter determination method and parameter control method

Abstract

The invention relates to a wide-range wind shear generation system, a parameter determination method and a parameter control method, and belongs to the technical field of wind field simulation. The system comprises a wind field generation device, a wind direction adjustment device and a wind field simulation cabin which are arranged in sequence; the wind field generating device comprises a plurality of fans, the fans are connected with a control module, and the control module is connected with an upper computer; the wind field simulation cabin is internally provided with a plurality of wind speed sensors which are located in the wind field simulation cabin, have the same flow direction and are connected with the control module. The wind direction adjusting device comprises a mounting frame, a plurality of cross rods and vertical rods which are arranged in a staggered mode are rotationally connected into the mounting frame, driving parts which drive the cross rods and the vertical rods to rotate and are connected with the control module are arranged on the mounting frame, baffles are fixedly connected to the cross rods and the vertical rods, and when all the baffles are located on the same plane, the edges of every two adjacent baffles are attached to each other. The method has the advantages that the performance and safety characteristics of the aircraft in the complex and changeable low-altitude wind environment are comprehensively known, and safety guarantee is provided.

Description

Technical Field

[0001] The present application relates to the technical field of wind field simulation, and in particular to a wide-range wind shear generation system, a parameter determination method, and a parameter control method. Background Art

[0002] As a typical representative of new-quality productivity, the low-altitude economy has been clearly listed as a strategic emerging industry in my country. It has huge development potential and broad market prospects. Low-altitude flight activities, as the final output form of the low-altitude economy, cover many fields, such as general aviation, drone logistics, low-altitude tourism, etc., and are of great significance to promoting economic growth, promoting industrial upgrading and improving the level of social services.

[0003] The complex wind environment at low altitude has seriously restricted the development of the low-altitude economy. Complex wind conditions such as low-altitude wind shear and gusts pose a strong threat to flight safety and greatly limit the development of low-altitude flight activities. In real life, the complex wind environment at low altitude changes dynamically, and wind shear, gusts, etc. are random and uncertain. Existing wind tunnel devices mostly produce stable wind fields, and do not incorporate the generation of complex and subtle wind conditions such as weak shear flow into the core design goals. They cannot truly reproduce the dynamic changes of wind shear and gusts in the low-altitude wind environment. When using existing wind tunnel devices for aircraft testing, only the performance data of the aircraft under a single, stable wind condition can be obtained. There is a lack of effective evaluation of the response characteristics under complex wind conditions such as continuously changing wind shear, gusts and weak shear flow. This leads to the fact that after the aircraft is actually put into low-altitude flight activities, its safety and reliability cannot be fully guaranteed when facing the complex and changeable low-altitude wind environment, increasing the risk of flight accidents. Summary of the Invention

[0004] In order to fully understand the performance and safety characteristics of aircraft in complex and changeable low-altitude wind environments and provide adequate safety guarantees, the present application provides a wide-range wind shear generation system, parameter determination method, and parameter control method.

[0005] In a first aspect, the present application provides a wide-range wind shear generation system, which adopts the following technical solutions:

[0006] A wide range wind shear generation system includes a wind field generating device and a wind field simulation cabin, wherein a wind direction adjustment device is provided between the wind field generating device and the wind field simulation cabin;

[0007] The wind field generating device includes a plurality of wind turbines, each of which is connected to a control module, which is connected to a host computer, and a speed sensor is provided on each wind turbine, which is connected to the control module;

[0008] The wind field simulation cabin is provided with a plurality of wind speed sensors for detecting the shear rate in the wind field simulation cabin, the plurality of wind speed sensors are located on the same fixed profile in the wind field simulation cabin, and the wind speed sensors are connected with the upper computer;

[0009] The wind direction adjusting device comprises a mounting frame, a plurality of staggered horizontal rods and vertical rods are rotationally connected in the mounting frame, a plurality of driving members for driving the horizontal rods and vertical rods to rotate are arranged on the mounting frame, the driving members correspond to the horizontal rods and vertical rods one by one, the driving members are connected with the control module, and each horizontal rod and vertical rod is fixedly connected with a baffle.

[0010] By adopting the above technical scheme, the rotation speed of each fan is adjusted in real time through the linkage of the control module and the upper computer, the wind speed sensors arranged in the wind field simulation cabin synchronously collect the wind speed on the same profile and calculate the actual shear rate through the control module, the upper computer drives the horizontal rods and vertical rods to rotate to realize fine adjustment of the angle of the baffle, the inclination angle of the baffle is controlled, the local wind field flow direction is changed, the difference between the actual shear rate and the target shear rate is adjusted, the low-altitude complex wind environment is accurately simulated, and sufficient safety guarantee is provided for comprehensive understanding of the performance and safety characteristics of the aircraft under extreme conditions.

[0011] Optionally, the wind field generating device and the wind direction adjusting device are provided with a honeycomb plate.

[0012] By adopting the above technical scheme, the introduction of the honeycomb plate significantly improves the performance and reliability of the wide-range wind shear generation system through multiple mechanisms such as rectification, voltage stabilization, noise reduction and equipment protection.

[0013] Optionally, the honeycomb plate and the wind field simulation cabin are provided with a damping net.

[0014] By adopting the above technical scheme, the introduction of the damping net significantly improves the wind field quality and experimental environment stability of the wide-range wind shear generation system through multiple mechanisms such as secondary rectification, noise reduction, buffering and filtering.

[0015] In the second aspect, the application provides a parameter determination method of a wide-range wind shear generation system, which adopts the following technical scheme:

[0016] A parameter determination method of a wide-range wind shear generation system, applied to the wide-range wind shear generation system in the first aspect, and characterized in that the method comprises the following steps:

[0017] Obtaining multiple sets of simulation data, each set of simulation data including fan rotating speeds of each row or each column in the wind field generating device and wind speeds detected by multiple wind speed sensors in the wind field simulation cabin at a fixed profile;

[0018] Constructing a linear regression model based on the fan rotating speeds and the corresponding wind speeds;

[0019] Based on the linear regression model, inversely designing to obtain a distribution formula of the fan rotating speeds on the row or column of the target shear profile.

[0020] By adopting the above technical solution, by collecting actual fan rotating speed-wind speed data pairs, a linear regression model is constructed, and by inversely designing the linear regression model, a distribution formula of the fan rotating speeds on the row or column of the target shear profile is obtained, so as to realize customized adjustment of shear flow, realize accurate simulation of low-altitude complex wind environment, and thus provide sufficient safety guarantee for comprehensively understanding the performance and safety characteristics of the aircraft under extreme conditions.

[0021] Optionally, the linear regression model is =A +b;

[0022] Calculating the coefficient matrix and the bias matrix based on the LASSO regression algorithm;

[0023] wherein, is the distribution of the fan rotating speeds on the row or column, is the wind speed of a fixed profile, A is the coefficient matrix of the linear regression model, and b is the bias matrix of the linear regression model.

[0024] Optionally, the distribution formula of the fan rotating speeds on the row or column of the target shear profile is: = wherein, is the distribution formula of the fan rotating speeds on the row or column, A is the coefficient matrix of the linear regression model, and b is the bias matrix of the linear regression model, is the speed of the target shear profile.

[0025] Optionally, in the case that there is a difference between the actual shear rate and the target shear rate, the Nelder-Mead method and the genetic algorithm are adopted to determine the target swing angle, the target frequency of the baffle, and the fan rotating speed adjustment value, so as to adjust the actual shear rate.

[0026] In a third aspect, the application provides a parameter control method of a wide-range wind shear generation system, which adopts the following technical solution:

[0027] A parameter control method of a wide-range wind shear generation system, applied to an upper computer, comprising:

[0028] acquire a target shear rate;

[0029] The wind turbine rotation speed distribution on the row or column based on the target shear profile wind turbine rotation speed distribution formula and the target shear rate determines the wind turbine rotation speed distribution on the row or column.

[0030] Based on the wind turbine rotation speed distribution on the row or column, the target rotation speed of each wind turbine is determined.

[0031] Based on the target rotation speed, the corresponding wind turbine is controlled by the control module to obtain the target shear rate.

[0032] By adopting the above technical scheme, the wind turbine rotation speed distribution on the row or column corresponding to the target shear rate is determined through the wind turbine rotation speed distribution formula on the row or column of the target shear profile, so as to solve the problem of wide range wind shear customization generation in low altitude airspace, so that small shear rate shear inflow generation can be realized, and large shear rate shear inflow generation can also be realized, thereby providing sufficient safety guarantee for comprehensively understanding the performance and safety characteristics of the aircraft under extreme conditions.

[0033] Optionally, in the control of the rotation speed of the corresponding wind turbine of the wind field generating device based on the target rotation speed by the control module, it further comprises:

[0034] Real-time acquisition of the target rotation speed and the actual rotation speed;

[0035] Calculate the error value between the target rotation speed and the actual rotation speed;

[0036] Based on the error value and the PID algorithm, a correction value is calculated;

[0037] Based on the correction value, the rotation speed of the wind turbine is adjusted.

[0038] By adopting the above technical scheme, after the initial control based on the wind turbine rotation speed distribution formula is completed, the real-time rotation speed feedback and the PID closed-loop correction mechanism are introduced, which can significantly improve the dynamic tracking accuracy, anti-interference ability and long-term stability of the wide range wind shear generation system.

[0039] Optionally, the method further comprises:

[0040] Real-time acquisition of the actual shear rate in the wind field simulation cabin after adjusting the rotation speed of the wind turbine;

[0041] In the case that the actual shear rate and the target shear rate are different, the average value of the overall difference between the target shear flow velocity profile and the actual shear flow velocity profile is taken as a global objective function, and the average value of the difference between the velocity profile of the preset region and the target velocity profile corresponding to the preset region is taken as a local objective function.

[0042] The optimization of the local target function drags the optimization of the corresponding local position of the target swing angle, the target frequency and the fan speed adjustment value, and the optimization of the global target function drags the optimization of the overall target swing angle, the target frequency and the fan speed adjustment value.

[0043] By adopting the technical scheme, high-precision speed control fans and precise closed-loop speed regulation methods are adopted, wide-range shear inflow generation devices are constructed by combining the angles and frequencies of the baffles, and a genetic algorithm based on the descending simplex is adopted to perform data-driven non-model optimization on distributed control parameters, so as to realize precise customized generation of wide-range shear inflows.

[0044] In the technical scheme, the control module is linked with the upper computer to adjust the rotating speeds of the fans in real time, multiple wind speed sensors arranged in the wind field simulation cabin synchronously collect wind speeds on the same profile and calculate actual shear rates through the control module, the upper computer independently drives the horizontal rod-vertical rod to rotate to realize fine adjustment of the angles of the baffles, the inclination angles of the baffles are controlled to change the flow direction of the local wind field, the difference between the actual shear rate and the target shear rate is adjusted, precise simulation of the low-altitude complex wind environment is realized, in the technical scheme, the linear reverse design method is adopted to obtain the approximate position of the target shear flow field, a non-model method based on distributed control is adopted to perform fine design on the wide-range shear inflow, the design error with the expected flow field is reduced, sufficient safety is provided for comprehensive understanding of the performance and safety characteristics of the aircraft under extreme conditions, and the technical scheme provides basic equipment support for aerodynamic and flight control performance tests of low-altitude aircrafts under wide-range wind shear conditions and helps low-altitude flight safety. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 is a structural schematic diagram of a wide-range wind shear generation system in the embodiment of the application.

[0046] Figure 2 is a structural schematic diagram of a wind field generation device in the embodiment of the application.

[0047] Figure 3 is a structural block diagram of a control module in the embodiment of the application.

[0048] Figure 4 is a structural schematic diagram of a wind direction adjustment device in the embodiment of the application.

[0049] Figure 5 is a structural schematic diagram of the embodiment of the application when all the baffles are in the same plane, and the edges of two adjacent baffles are attached.

[0050] Figure 6 is a flowchart of a parameter determination method of a wide-range wind shear generation system embodied in the embodiments of the present application.

[0051] Figure 7 is a flowchart of a parameter control method of a wide-range wind shear generation system embodied in the embodiments of the present application.

[0052] Figure 8 is a schematic diagram of closed-loop control of the fan rotating speed by using PID embodied in the embodiments of the present application.

[0053] Figure 9 is a schematic diagram of target shear rate and actual shear rate embodied in the embodiments of the present application.

[0054] Figure 10 is a schematic diagram of parameter adjustment by using genetic algorithm based on the descent simplex method embodied in the embodiments of the present application.

[0055] Figure 11 is a schematic diagram of combination of the PID controller and the genetic algorithm based on the descent simplex method embodied in the embodiments of the present application.

[0056] In the figure, 1, wide-range wind shear generation system; 11, wind field generating device; 111, fan; 1111, rotating speed sensor; 12, wind field simulation cabin; 121, wind speed sensor; 13, wind direction adjusting device; 131, mounting frame; 132, horizontal rod; 133, vertical rod; 134, driving member; 135, baffle; 136, control module; 137, upper computer; 14, honeycomb plate; 15, damping net. DETAILED DESCRIPTION

[0057] The present application will be further described below in conjunction with the accompanying drawings.

[0058] The present embodiments are merely explanatory of the present application, and are not intended to limit the present application. Those skilled in the art can make modifications to the present embodiments without creative contribution after reading the present specification, and the modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

[0059] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are some, but not all of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative contribution fall within the scope of the present application.

[0060] In this document, the term "and / or" simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document, unless otherwise specified, generally indicates an "or" relationship between the related objects.

[0061] Before describing the embodiment, the intensity of wind shear is explained. The International Civil Aviation Organization divides the intensity of wind shear into four levels, as shown in Table 1. Currently, most devices cannot generate wind shear with a shear rate of 0 to 0.2s. -1 The shear flow.

[0062] Table 1

[0063]

[0064] The embodiments of the present application are described in further detail below with reference to the accompanying drawings.

[0065] The embodiment of the present application provides a wide range wind shear generation system, such as Figure 1 As shown, the wide-range wind shear generation system 1 includes a wind field generating device 11 and a wind field simulation cabin 12 , and a wind direction adjusting device 13 is provided between the wind field generating device 11 and the wind field simulation cabin 12 .

[0066] like Figure 2 and Figure 3 As shown, the wind farm generating device 11 includes a plurality of wind turbines 111. In this embodiment, the wind farm generating device 11 is composed of 13*13 wind turbines 111, and 3×3 wind turbines 111 are composed of a wind turbine module. Each wind turbine module is powered by a 2kW single-phase power supply. Each wind turbine module is connected to a control module 136, wherein there can be one control module 136 or multiple control modules 136, or one wind turbine module corresponds to one control module 136. There is no specific limitation on this, as long as it can control all wind turbines 111. The control module 136 can be wirelessly connected to the wind turbine 111 or electrically connected to the wind turbine 111. The control module 136 is connected to a host computer 137, and the speed of the wind turbine 111 is controlled by the host computer 137 and the control module 136. A speed sensor 1111 is also provided on the wind turbine 111, and the speed sensor 1111 is connected to the control module 136. In this embodiment, the speed sensor 1111 adopts a Hall element, and the control module 136 adopts 3 The STM32 single-chip microcomputer, the control module 136 and the host computer 137 communicate using a network cable plus a switch, which can achieve fast transmission of downlink signals compared to the CAN bus method.

[0067] The wind field simulation cabin 12 is provided with a plurality of wind speed sensors 121 for detecting the shear rate in the wind field simulation cabin 12. The plurality of wind speed sensors 121 are located on the same fixed profile in the wind field simulation cabin 12 and are uniformly distributed. The wind speed sensor 121 is wirelessly connected to the upper computer 137. In this embodiment, the wind speed sensor 121 is a pitot tube or a hot-wire anemometer. The wind field simulation cabin 12 can be an open wind tunnel or a closed wind tunnel, which is not limited here.

[0068] As shown in Figure 3 and Figure 4 , the wind direction adjusting device 13 comprises a mounting frame 131, a plurality of staggered horizontal rods 132 and vertical rods 133 are rotatably connected in the mounting frame 131, a plurality of driving members 134 for driving the rotation of the horizontal rods 132 and the vertical rods 133 are arranged on the mounting frame 131, the driving member 134 is a stepping motor, each horizontal rod 132 and each vertical rod 133 corresponds to one driving member 134, the driving member 134 is connected with the control module 136. The control module 136 here can be the control module for controlling the fan 111 or a new control module, which is not limited here. Each horizontal rod 132 and vertical rod 133 is fixedly connected with a baffle 135. As shown in Figure 5 , when all the baffles 135 are in the same plane, the edges of the adjacent two baffles 135 are in close contact.

[0069] As shown in Figure 1 , the wind field generating device 11 and the wind direction adjusting device 13 are provided with a honeycomb plate 14, and the honeycomb plate 14 and the wind field simulation cabin 12 are provided with a damping net 15. The honeycomb plate 14 is used for air flow regulation and equalization treatment, and the damping net 15 is used for further adjusting the air flow characteristics and reducing the air flow turbulence degree, so as to make the air flow entering the wind field simulation cabin 12 more uniform and stable, and to provide a required air flow environment for wind shear simulation.

[0070] The application also provides a parameter determination method of a wide-range wind shear generation system, which is applied to the wide-range wind shear generation system as shown in Figure 6 , and the main process of the method is described as follows (steps S101-S103):

[0071] In step S101, a plurality of groups of simulation data are obtained, each group of simulation data comprising the rotation speed of each row or column of fan in the wind field generating device and the wind speed detected by the plurality of wind speed sensors in the wind field simulation cabin on a fixed profile;

[0072] In the embodiment, the fan rotating speed of each row or each column is fixed, and the fan rotating speed of each fan and the wind speed detected by each wind speed sensor in the wind field simulation cabin at the time, i.e., the shear rate generated in the transverse or spanwise direction, are recorded; the fan rotating speed of each row or each column is changed multiple times, and the wind speed generated in the wind field simulation cabin multiple times, i.e., the wind speed detected by each wind speed sensor when the fan rotating speed is changed each time, is obtained; the fan rotating speed and the corresponding wind speed form a set of simulation data, and multiple sets of simulation data are obtained at this time, wherein the fan rotating speed of the fans in each row or each column can be the same or different each time the fan rotating speed is adjusted, and no specific limitation is made thereto.

[0073] In the embodiment, is the distribution of the fan rotating speed in the row or column, wherein n is the number of rows or columns, and in the embodiment, n = 13, is the wind speed detected by a plurality of wind speed sensors in the wind field simulation cabin flowing to a fixed profile, and in the embodiment, the number of wind speed sensors can be 64, i.e., m = 64, and can also be other numbers, and no specific limitation is made thereto.

[0074] It should be noted that in the embodiment, the wind speed sensors are numbered according to the arrangement order, so that the shear rate generated in the wind field simulation cabin can be quickly determined according to the arrangement order of the wind speed sensors.

[0075] In step S102, a linear regression model is constructed based on the fan rotating speed and the corresponding wind speed.

[0076] In the embodiment, the fan rotating speed and the corresponding wind speed form a pair of input data and output data, and the mapping relationship between the fan rotating speed and the shear rate is constructed according to the input data and the output data, i.e., given a fan rotating speed input, the estimated value of the real wind speed output can be obtained, and the linear regression model =A +b; the coefficient matrix and the bias matrix are calculated based on the LASSO regression algorithm; wherein, is the distribution of the fan rotating speed in the row or column, is the wind speed of a fixed profile, A is the coefficient matrix of the linear regression model, and b is the bias matrix of the linear regression model.

[0077] In the embodiment, the linear proxy model (A, b) is solved from the input-output matrix by using the regularized linear regression, the linear proxy model (A, b) is converted into a minimum L2 norm problem, and in order to regularize, the L1 norm of A, b is penalized, and therefore the expression of the regression problem is:

[0078] a (| +| ), wherein , A is a coefficient matrix, b is a bias matrix of the linear regression model, R is an input matrix, N date is the number of simulation data sets, is the L1 norm of the matrix A, is the L1 norm of the vector b, is the L2 norm.

[0079] In the present embodiment, it is necessary to use tens of simulation data sets, such as 50 sets, 60 sets.

[0080] Step S103, based on the linear regression model, inverse design is performed to obtain a distribution formula of the fan rotating speed on the row or column of the target shear profile.

[0081] In the present embodiment, after obtaining the linear proxy model (A, b) of the shear flow, the linear proxy model is used to perform inverse design of the target shear flow velocity profile, i.e., the shear rate, and the linear proxy model is used to determine the distribution formula of the fan rotating speed on the row or column closest to the target shear velocity profile:

[0082] , wherein is the distribution formula of the fan rotating speed on the row or column, A is a coefficient matrix of the linear regression model, b is a bias matrix of the linear regression model, is the velocity of the target shear profile.

[0083] It should be noted that due to the high-dimensional nonlinearity of the flow field generated by the wind field generating device, the linear regression model can preliminarily estimate the fan rotating speed distribution under a certain shear rate, but there may still be some differences with the target value, especially under weak shear flow conditions, small amplitude changes in fan rotating speed may cause differences in shear rate. The fan rotating speed distribution obtained by inverse design is used as the initial value of the distributed control non-model customized wide-range shear flow, thereby greatly reducing the iteration space and accelerating the machine learning process of fine shear flow customization.

[0084] In the case where the actual shear rate and the target shear rate differ, the Nelder-Mead method and the genetic algorithm are used to determine the target swing angle of the baffle, the target frequency of the baffle rotation, and the fan rotating speed adjustment value to adjust the actual shear rate, so as to achieve the target shear rate.

[0085] In the present embodiment, an example is used to illustrate the determination of the fan rotating speed.

[0086] , wherein r1 represents the rotating speed of the first row of fans, r2 represents the rotating speed of the second row of fans, and r3 represents the rotating speed of the third row of fans, Four different fan rotating speed combinations are used for testing. ​

[0087] It should be noted that the fan speed of the same row can be the same, and can also be different, which is not specifically limited.

[0088] | Test number | r1 (rpm) | r2 (rpm) | r3 (rpm) |

[0089]

[0090] v1, v2, v3 are the wind speeds measured by the three wind speed sensors flowing to a certain fixed profile, and the corresponding data are as follows:

[0091] | Test number | v1 (m / s) | v2 (m / s) | v3 (m / s) |

[0092] .

[0093] The input matrix R and the output matrix V are respectively: , v= .

[0094] The linear regression model is modeled according to the formula =A +b, and the coefficient matrix A and the bias matrix b are solved using the linear regression method.

[0095] A= , b= .

[0096] For a new fan speed combination of each row, for example =[11,16,21], that is, the fan speed of the first row is 11 rpm, the fan speed of the second row is 16 rpm, and the fan speed of the third row is 21 rpm, and the predicted speed is:

[0097] .

[0098] Linear inverse design of shearing incoming flow to fan speed: target shearing speed profile m / s, that is, at the target measurement profile, the speeds corresponding to the three wind speed sensors are 5.2 m / s, 7.2 m / s and 8.2 m / s respectively.

[0099] The inverse calculation is according to the formula = , r= , then

[0100] Ar+b= , minimize

[0101] .

[0102] By numerical optimization method, assuming to get approximate each row fan speed distribution = rpm, namely the first row fan speed is 13 rpm, the second row fan speed is 18 rpm, and the third row fan speed is 23 rpm.

[0103] The application also provides a parameter control method of a wide-range wind shear generation system, which is applied to a host computer, as shown in FIG. 1, and the main process of the method is described as follows (steps 201-204): Figure 7

[0104] Step 201, obtaining a target shear rate;

[0105] In this embodiment, the user inputs the target shear rate into the host computer through a mouse, a keyboard or other input devices of the host computer, and the host computer obtains the target shear rate.

[0106] Step 202, determining the distribution of fan speeds on rows or columns based on a fan speed determination method and the target shear rate;

[0107] In this embodiment, after the host computer obtains the target shear rate, the distribution of fan speeds on rows or columns corresponding to the target shear rate is calculated by using the above-mentioned fan speed determination method, .

[0108] Step 203, determining a target speed of each fan based on the distribution of fan speeds on rows or columns;

[0109] Step 204, controlling the corresponding fan by using a control module based on the target speed, so as to obtain the target shear rate.

[0110] In this embodiment, the host computer obtains the fan number corresponding to each calculated fan speed, and sends the target speed and the fan number to the control module. The control module determines the fan corresponding to the number in the wind field generation device based on the target speed, and controls the fan with the number in the wind field generation device based on the target speed, wherein the number of the fan in the wind field generation device corresponds to the calculated fan number one by one.

[0111] It should be noted that the fan speeds of the same row or the same column of the wind field generation device can be the same or different, which is not limited here.

[0112] After the control module controls the speed of the corresponding fan of the wind field generation device based on the target speed, the method further includes: obtaining the target speed and the actual speed in real time; calculating the error value between the target speed and the actual speed; calculating the correction value based on the error value and the PID algorithm; and adjusting the fan speed based on the correction value.​

[0113] Figure 8 The schematic diagram of closed-loop control of fan speed using PID, where target speed is the target speed, speed err is the speed difference, real speed is the actual speed, PID controller is PID control, MCU is the micro control unit, PWM is the duty cycle, FG Singnal is the FG signal. In this embodiment, the control module sends the wind speed detected by the wind speed sensor to the host computer in real time. The Hall element of the fan outputs a square wave of the corresponding frequency when the motor magnetic poles alternate, which is the FG signal. The actual speed is calculated using the FG signal. The timer peripheral of the control module can generate a high-precision pulse width modulation signal, namely a PWM signal. The 16-bit registers ARR and CCR control the PWM period and duty cycle, respectively. Changing the value of the CCR register generates PWM signals with different duty cycles. Controlling the on and off of the MOS tubes in the H-bridge circuit can simulate the voltage and change the fan speed. When there is an error between the actual speed and the target speed, the error is transmitted to the incremental PID algorithm to calculate the correction value. After conversion, the ARR register value is corrected and the PWM duty cycle is adjusted. The target speed is approached by continuous iteration to achieve precise speed control. To avoid current backflow, signal interference, etc., a high-speed optocoupler is used to transmit the signal. An electromagnetic isolation element is used to isolate the controller from the fan power supply, and a parallel capacitor is connected in the circuit for filtering.

[0114] After determining the approximate position of the target shear flow using the distribution formula of the fan speed in the row or column of the target shear profile, a non-model method of distributed control is used to fine-tune the shear flow to reduce the design error from the expected flow field.

[0115] Specifically, the actual shear rate in the wind field simulation cabin after the fan speed is adjusted is obtained in real time; when there is a difference between the actual shear rate and the target shear rate, the average value of the overall difference between the target shear flow velocity profile and the actual shear flow velocity profile is used as the global objective function, and the average value of the difference between the velocity profile of the preset area and the target velocity profile corresponding to the preset area is used as the local objective function; the local objective function is used to drive the optimization of the target swing angle, target frequency and fan speed adjustment value of the corresponding local position, and the global objective function is used to drive the optimization of the overall target swing angle, target frequency and fan speed adjustment value.

[0116] In this embodiment, the shear rate that the user wants to obtain is as follows Figure 9 As shown in a, the actual shear rate may be biased, resulting in Figure 9The shear rate shown in the middle b needs to reduce the design error with the expected flow field, and the wind direction adjusting device is further adjusted, the shear rate of the adjusted wind field simulation cabin is fed back by the wind speed sensor, and the wind field simulation cabin reaches the target shear rate.

[0117] In this embodiment, the genetic algorithm based on the reduced simplex method is used to adjust the target shear flow with the determined approximate position. The genetic algorithm has the disadvantage of slow convergence in actual application, strong global search ability, but weak local search ability. The reduced simplex method is a gradient-based method, and the search ability of local optimum is very strong.

[0118] In this embodiment, starting from the idea of algorithm mixing, the reduced simplex method is implanted to accelerate the fast search of the algorithm for local optimum, shorten the evolution time of the control law, and complement each other. The genetic algorithm based on the reduced simplex method is as shown in Figure 10 Starting from the first generation, the control law group generated by the genetic random algorithm is tested one by one, and the control target function is calculated based on the information of each sensor. According to the increasing sequence of the target function , the control law group is divided into p subgroups, and the reduced simplex method is executed on each subgroup to calculate the corresponding control target function quantization value; the above control law and the corresponding target function are replaced in the database formed in the evolution process of the genetic algorithm, and a new control law group and the corresponding target function quantization value are obtained. The genetic algorithm uses gene operations such as elite, genetic, hybridization, and mutation to generate the next generation of control law group. Repeat the accelerated learning algorithm of the genetic algorithm based on the reduced simplex, and continuously evolve and iterate until convergence to obtain the optimal control law.

[0119] In this embodiment, starting from the target shear flow, the genetic algorithm based on the reduced simplex method is used to optimize the fan speed, baffle swing angle and baffle rotation frequency, so as to obtain accurate shear flow.

[0120] In this embodiment, first, the target function is defined, the average of the absolute value of the overall difference between the target shear flow velocity profile and the experimental test shear flow velocity profile is defined as the global target function, and the average of the difference between the local wind speed sensor and the corresponding target velocity profile is defined as the local target function. The local target function is used to optimize the local position fan speed, baffle rotation frequency and baffle swing angle, and the global target function is used to optimize the overall distributed control parameters.

[0121] Figure 11The schematic diagram of the PID controller combined with the genetic algorithm based on the reduced simplex method is shown in the figure. When the target shear inflow is obtained by the upper computer, the target shear inflow is input into the inverse design to obtain the distribution of the fan speed in the row or column, so as to determine the target speed of each fan. Then, the target speed is used for rotation, the wind speed sensor is used to determine the experimental test shear flow velocity profile, the wind speed difference value between the target shear flow velocity profile and the experimental test shear flow velocity profile is calculated, the fan speed is optimized through the wind speed difference value and the genetic algorithm based on the reduced simplex method, the speed adjustment value is obtained, the fan speed is controlled by the PID control and the wind speed adjustment value, and the target shear rate is obtained.

[0122] In the technical scheme of the application, the shear inflow with small shear rate can be generated, the shear inflow with large shear rate can be generated, and the shear inflow can be designed reversely by specifying the shear rate, thereby providing basic equipment support for the aerodynamic and flight control performance test of the low-altitude aircraft under the wide-range wind shear condition, and assisting the low-altitude flight safety.

[0123] The terms "comprising", "containing", or any other similar term are intended to encompass non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or other elements inherent in such process, method, article or device.

[0124] The above description is only the preferred embodiment of the application and the explanation of the applied technical principles. Those skilled in the art should understand that the application range involved in the application is not limited to the technical scheme formed by the specific combination of the above technical features, and also covers other technical schemes formed by any combination of the above technical features or equivalent features without departing from the above application concept. For example, the above features are replaced with the technical features with similar functions applied in the application (but not limited to) to form the technical scheme.

Claims

1. A wide range wind shear generation system, characterized in that: It includes a wind field generating device and a wind field simulation cabin, wherein a wind direction adjusting device is provided between the wind field generating device and the wind field simulation cabin; The wind field generating device includes a plurality of wind turbines, each of which is connected to a control module, which is connected to a host computer, and a speed sensor is provided on each wind turbine, which is connected to the control module; The wind field simulation cabin is provided with a plurality of wind speed sensors for detecting the shear rate in the wind field simulation cabin, the plurality of wind speed sensors are located on the same fixed cross-section of the flow direction in the wind field simulation cabin, and the wind speed sensors are connected to the host computer; The wind direction adjustment device includes a mounting frame, in which a plurality of staggered horizontal bars and vertical bars are rotatably connected. A plurality of driving members for driving the horizontal bars and vertical bars to rotate are provided on the mounting frame, and the driving members correspond one-to-one to the horizontal bars and vertical bars. The driving members are connected to a control module, and a baffle is fixedly connected to each of the horizontal bars and vertical bars. When all the baffles are in the same plane, the edges of two adjacent baffles fit together.

2. A wide range wind shear generation system according to claim 1, characterized in that: A honeycomb panel is provided between the wind field generating device and the wind direction adjusting device.

3. A wide range wind shear generation system according to claim 2, characterized in that: A damping net is provided between the honeycomb panel and the wind field simulation cabin.

4. A method for determining parameters of a wide-range wind shear generation system, applied to a wide-range wind shear generation system according to any one of claims 1 to 3, characterized in that: include: Acquire multiple sets of simulation data, each set of simulation data including the rotational speed of the wind turbines in each row or column of the wind field generating device and the wind speed detected by multiple wind speed sensors in a wind field simulation cabin at a fixed cross section; Constructing a linear regression model based on the fan speed and the corresponding wind speed; Based on the linear regression model, reverse design is performed to obtain a distribution formula of the fan speed in the target shear section on the row or column.

5. The method for determining parameters of a wide range wind shear generation system according to claim 4, characterized in that: The linear regression model is =A +b; Calculate the coefficient matrix and bias matrix based on the LASSO regression algorithm; in, is the distribution of fan speed in rows or columns, is the wind speed of a fixed section, A is the coefficient matrix of the linear regression model, and b is the bias matrix of the linear regression model.

6. The method for determining parameters of a wide range wind shear generation system according to claim 5, characterized in that: The distribution formula of the fan speed of the target shear section in rows or columns is: = ,in, is the distribution formula of fan speed in rows or columns, A is the coefficient matrix of linear regression model, b is the bias matrix of linear regression model, is the velocity of the target shear section.

7. The method for determining parameters of a wide range wind shear generation system according to claim 6, characterized in that: When there is a difference between the actual shear rate and the target shear rate, the descending simplex method and genetic algorithm are used to determine the target swing angle of the baffle, the target frequency and the fan speed adjustment value to adjust the actual shear rate.

8. A parameter control method for a wide range wind shear generation system, characterized in that: Applied to the host computer, including: Obtain target shear rate; Determine the distribution of the fan speed in rows or columns based on the distribution formula of the fan speed in the target shear profile obtained by the parameter determination method of a wide range wind shear generation system according to any one of claims 4 to 7 and the target shear rate; Determining a target speed for each wind turbine in the wind farm generating device based on the distribution of the wind turbine speeds in rows or columns; Based on the target rotational speed, a control module is used to control the rotational speed of a corresponding fan of the wind field generating device to obtain a target shear rate.

9. The parameter control method of a wide range wind shear generation system according to claim 8, characterized in that: After controlling the rotation speed of the wind turbine corresponding to the wind farm generating device by using the control module based on the target rotation speed, the method further includes: Get target speed and actual speed in real time; Calculating an error between the target speed and the actual speed; Calculating a correction value based on the error value and a PID algorithm; The rotation speed of the fan is adjusted based on the correction value.

10. A parameter control method for a wide range wind shear generation system according to claim 8 or 9, characterized in that: The method further comprises: Obtain the actual shear rate in the wind field simulation cabin in real time after adjusting the fan speed; In the case where there is a difference between the actual shear rate and the target shear rate, the average value of the overall difference between the target shear flow velocity profile and the actual shear flow velocity profile is used as the global objective function, and the average value of the difference between the velocity profile of the preset area and the target velocity profile corresponding to the preset area is used as the local objective function; The local objective function drives the optimization of the target swing angle, target frequency and fan speed adjustment value of the corresponding local position, and the global objective function drives the optimization of the overall target swing angle, target frequency and fan speed adjustment value.

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