Multi-node loading platform of radar radome, method of using and multi-node loading control method

Abstract

The application provides a multi-node loading platform of a radar radome, a use method and a multi-node loading control method, and comprises a base assembly, a loading assembly, a support assembly and a test piece interface. The base assembly comprises a plurality of base parts that can be detachably spliced, a guide rail and a rack. The loading assembly comprises a loading column, a vertical moving assembly, an angle adjusting assembly, a loading actuator and a positioning and fixing assembly. The loading column is movably arranged on the base assembly through the transmission of the rack and the guidance of the guide rail. The vertical moving assembly, the angle adjusting assembly and the positioning and fixing assembly are arranged on the loading column. The support assembly comprises a support base, a support platform and the test piece interface. The support platform is fixedly arranged on the support base, and the test piece interface is arranged on the support platform and used for mounting a radar radome test piece. Through the above structure, the universal flexible adaptation and accurate positioning of the radar radome test piece of different sizes and different loading point layouts under multiple working conditions are realized.

Description

Technical Field

[0001] This invention relates to the technical field of aircraft structural strength testing equipment, specifically to a multi-node loading platform for a radar radome, its usage method, and a multi-node loading control method. Background Technology

[0002] Aircraft radar radomes are functional structural components that integrate requirements for aerodynamic shape, structural strength, and electrical performance. Their main functions are to improve the aerodynamic shape of the aircraft, protect the internal antenna system from the influence of the external environment, and ensure the accuracy of the antenna surface and position.

[0003] The radar radome primarily withstands loads including inertial loads, aerodynamic loads, discrete source impacts, and bird strike loads. The evaluation tests conducted include static tests, damage tolerance tests (including static tests on damaged radar radome structures), and bird strike tests. Among these, static tests and damage tolerance tests require equivalent load processing to transform the aerodynamic and inertial loads onto the radome surface, making it impossible to directly apply loads to the original structure. This necessitates using specialized loading devices to achieve the evaluation results.

[0004] Currently, traditional static tests of radar radomes often employ on-site installation of loading columns and manual adjustment of actuators to locate loading nodes and apply loads. Specifically, operators must install loading columns one by one on the load-bearing floor according to test requirements, and adjust the spatial position and loading angle of each actuator through manual measurement and adjustment. Then, the actuators are connected to adhesive tape or tension / compression pads attached to the radome surface via a lever system, and finally, tensile and compressive loads are applied to complete the test.

[0005] However, the above-mentioned traditional methods have at least the following shortcomings:

[0006] First, the on-site setup and manual adjustment of the loading columns are time-consuming and labor-intensive, and the positioning accuracy depends on the operator's experience, making it difficult to guarantee consistency among multiple loading points.

[0007] Second, radar radomes come in various types and sizes. The number of loading points, spatial locations, and loading force directions required for different test pieces vary. Traditional methods require redesigning and building a loading frame for each test, resulting in poor versatility, long cycles, and high costs.

[0008] Third, the test conditions for radar radomes are numerous, and the location, number, and load value of loading points may change under different conditions. Traditional methods make it difficult to quickly switch between multiple conditions, resulting in low test efficiency.

[0009] To address the aforementioned issues, some patents have already improved the localized loading components in static tests of radar radomes. For example, Chinese patent CN207586001U discloses a tensile load loading block for static tests of radar radomes, which achieves tensile load loading through a combination of conformal parts, transition parts, and steering ball joints, aiming to solve the problem of excessive force concentration on the radar radome when tensile loads are applied using canvas straps. Chinese patent CN206740368U discloses a static test loading structure for radar radome pitot tube support rods, including a loading ring and steel wire rope, to achieve accurate and stable loading of the radar radome pitot tube support rods. CN110616046A proposes a tension-compression pad bonding method suitable for large-size, high-load radar radomes, which uses microwave heating to accelerate adhesive drying to ensure bonding quality.

[0010] However, the aforementioned existing patents only improve local components (loading blocks, tension and compression pads, and support rod loading structures) during the loading process, without addressing the design of the overall loading platform or considering the need for rapid and accurate testing of various types and sizes of radar radomes under multiple working conditions and attitudes.

[0011] Therefore, there is an urgent need to provide a multi-node loading platform for radar radomes that can overcome the above-mentioned shortcomings and its usage method. Summary of the Invention

[0012] In view of this, the embodiments of this specification provide a multi-node loading platform for radar radomes, a method of use, and a multi-node loading control method to improve the versatility of testing, the degree of automation, and the efficiency of switching operating conditions.

[0013] The embodiments in this specification provide the following technical solutions: A multi-node loading platform for radar radomes, comprising: The base assembly includes multiple detachable and connectable base segments, guide rails and racks mounted on the base segments; The loading component includes a loading column, a vertical movement component, an angle adjustment component, a loading actuator, and a positioning and fixing component. The loading column is movably mounted on the base assembly via rack and pinion drive and guide rail guidance; The vertical moving component is mounted on the loading column and is used to drive the loading actuator cylinder to move up and down in the vertical direction. The angle adjusting component is mounted on the loading column and is used to adjust the pitch angle of the loading actuator cylinder. The positioning and fixing component is mounted on the loading column and is used to lock the loading column at the target loading position. The support components include a support base, a support platform, and a test piece interface. The support base is used to fix the device to an external load-bearing foundation, the support platform is fixedly mounted on the support base, and the test piece interface is located on the support platform and is used to install the radar radome test piece.

[0014] Furthermore, the base consists of a first base component, a second base component, a third base component, and a fourth base component, which are sequentially spliced ​​end to end. The guide rail includes an outer guide rail and an inner guide rail, which are fixedly mounted on the upper surface of the base assembly. The rack is fixedly installed between the inner guide rail and the outer guide rail, and the rack is arranged parallel to the inner guide rail and the outer guide rail; The bottom of the loading column is equipped with gears and sliders. The gears mesh with the rack, and the sliders slide with the outer and inner guide rails.

[0015] Furthermore, the vertical movement component includes a trapezoidal lead screw and a first servo motor. The output shaft of the first servo motor is fixedly connected to one end of the trapezoidal lead screw, and the loading actuator is fixedly connected to the trapezoidal lead screw. The first servo motor drives the loading actuator to move vertically up and down through the trapezoidal lead screw. The angle adjustment component includes a second servo motor or a hoist, which is fixedly installed on the top of the loading column. The output end of the second servo motor or hoist is connected to the front end of the loading actuator cylinder.

[0016] Furthermore, a laser displacement rangefinder is installed at the front end of the loading actuator cylinder, and a tension / compression sensor is installed on the loading actuator cylinder; Laser displacement rangefinders are used to collect spatial displacement data of the loading point in real time, while tension and compression sensors are used to collect actual load data of the loading point in real time.

[0017] Furthermore, the radar radome multi-node loading platform also includes a lever system and quick-change connectors; One end of the lever system is connected to the output end of the loading actuator via a quick-connect coupling; The quick-change coupling is a pneumatic or hydraulic quick-change chuck.

[0018] A method for using a multi-node loading platform for a radar radome, the method comprising the following steps: Secure the base assembly and support assembly to the external load-bearing foundation, and adjust the relative positions of the base assembly and support assembly. Install the radar radome test piece onto the test piece interface of the support component; The total number of loading components is determined based on the number of maximum load application points required in all preset operating conditions of the radar radome test. Repeat the following steps until the static test for all preset working conditions is completed: The horizontal position of each loading component is adjusted by the guide rail and rack on the base assembly, the vertical position of the loading actuator is adjusted by the vertical movement component, and the pitch angle of the loading actuator is adjusted by the angle adjustment component. Each loaded component is locked by positioning the fixed component; After applying tensile and compressive loads to each loading actuator to complete the static test under the current working condition, the positioning and fixing components are released.

[0019] A multi-node loading control method for a radar radome multi-node loading platform includes the following steps: Acquire uniform aerodynamic load distribution data on the surface of the radar radome test piece, and generate target load vectors for each loading component based on the uniform aerodynamic load distribution data; Obtain the structural stiffness matrix of the test specimen, and construct a multi-input multi-output coupled inverse matrix based on the structural stiffness matrix of the test specimen; Acquire the actual force vector data output by each tension and compression sensor, and perform a difference calculation between the actual force vector data and the target load vector to generate the force deviation vector at the current moment; By inputting the force deviation vector into the coupling inverse matrix and performing decoupling iterative calculations, the independent drive compensation signals of each loaded actuator after eliminating multi-point load interference are obtained. The independent drive compensation signal is converted into a real-time drive current command for each loaded actuator, and the real-time drive current command is output to the servo valve of each loaded actuator.

[0020] Furthermore, target load vectors for each loading component are generated based on the uniformly distributed aerodynamic load distribution data, including: Acquire uniformly distributed aerodynamic load distribution data and inertial load distribution data on the surface of the radar radome test piece; The uniformly distributed aerodynamic load distribution data and the inertial load distribution data are vector-superimposed to generate superimposed load distribution data. Based on the principle that the total load and total moment remain unchanged, the superimposed load distribution data is discretized into multiple concentrated force node data, and the equivalent relationship between the resultant force and resultant moment between each concentrated force node data and the superimposed load distribution data is established. Based on the spatial layout constraints of each loading actuator, vector synthesis is performed on the data of each concentrated force node, and multiple concentrated force node data are merged into the equivalent load vector of each loading component, which serves as the target load vector of each loading component.

[0021] Furthermore, the process of converting the independent drive compensation signal into a real-time drive current command for each loaded actuator and outputting it to the servo valve of each loaded actuator also includes the following steps: Obtain the preset force line direction vector of each loading component and the spatial displacement data output by the laser displacement rangefinder; The spatial displacement data is solved to generate the displacement vector of the current actual loading point, and combined with the current attitude angle data of each loading actuator, the spatial angle deviation value between the current actual force line vector and the preset force line direction vector is generated. When the spatial angle deviation value exceeds the preset threshold, position compensation incremental signals for the vertical movement component and the angle adjustment component are generated based on the angle deviation value. The position compensation incremental signal is superimposed on the drive command generation end of the vertical movement component and the angle adjustment component.

[0022] Furthermore, it also includes: When switching to preset operating conditions, the following steps are included: Obtain the target load vectors of each loading component for the current working condition and the next working condition respectively, and compare the target load vectors of each loading component for the current working condition with the target load vectors of each loading component for the next working condition. When the target load vector of the next working condition is different from the target load vector of the current working condition, a quick-connect coupling switching control signal and a lever arm length adjustment signal of the lever system are generated according to the target load vector of the next working condition. The quick-change connector switching control signal is output to the control end of the quick-change chuck, and the lever arm length adjustment signal is output to the adjustment mechanism of the lever system.

[0023] Compared with the prior art, the beneficial effects that at least one technical solution adopted in the embodiments of this specification can achieve include at least: By enabling the detachable splicing of the base assembly and the multi-degree-of-freedom position and attitude angle adjustment of the loading assembly, the radar radome test pieces of different sizes and loading point layouts can be universally and flexibly adapted and precisely positioned under multiple working conditions. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is an overall structural diagram of the radar radome multi-node loading platform according to an embodiment of the present invention; Figure 2 This is a structural diagram of the base assembly according to an embodiment of the present invention; Figure 3 This is a structural diagram of the loading component according to an embodiment of the present invention; Figure 4 This is a structural diagram of the supporting components in an embodiment of the present invention.

[0026] The reference numerals in the figure are as follows: 1. Base assembly; 1011. First base component; 1012. Second base component; 1013. Third base component; 1014. Fourth base component; 102. Outer guide rail; 103. Inner guide rail; 104. Rack; 2. Loading assembly; 201. Loading column; 202. Vertical movement assembly; 203. Angle adjustment assembly; 204. Loading actuator; 205. Gear; 206. Slider; 207. Positioning and fixing assembly; 3. Support assembly; 301. Support base; 302. Support platform; 303. Test piece interface; 4. Radar radome test piece. Detailed Implementation

[0027] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] I. Multi-node loading platform for radar radome 1.1 Overall Structure like Figure 1 As shown, the present invention provides a multi-node loading platform for a radar radome, comprising three parts: a base assembly 1, a loading assembly 2, and a support assembly 3. Multiple loading assemblies 2 can be configured, the specific number determined according to the number of load application points on the radar radome test piece 4. The support assembly 3 is used to fix and support the radar radome test piece 4, the base assembly 1 is used to support the loading assemblies 2 and provide their sliding track in the horizontal plane, and the loading assemblies 2 are used to apply the required tensile and compressive loads to the radar radome test piece 4.

[0030] 1.2 Base Assembly like Figure 2 As shown, base assembly 1 serves as the foundation of the entire platform and is bolted to the load-bearing floor of the laboratory. Base assembly 1 comprises four base segments: the first base segment 1011, the second base segment 1012, the third base segment 1013, and the fourth base segment 1014. These four base segments are sequentially spliced ​​end-to-end to form a rounded rectangular frame structure. The base assembly 1 adopts a modular design, allowing for flexible selection of the combination method and number of base segments based on the size of the radar radome test piece 4 and the layout requirements of the loading points, thus meeting the loading requirements of test pieces of different sizes.

[0031] The base assembly 1 is provided with an outer guide rail 102, an inner guide rail 103, and a rack 104. The outer guide rail 102 and the inner guide rail 103 are respectively fixedly mounted on the upper surface of the base assembly, and are arranged in parallel to each other to provide sliding guidance for the loading assembly 2. The rack 104 is fixedly mounted between the inner guide rail 103 and the outer guide rail 102, and is arranged in parallel with the inner guide rail 103 and the outer guide rail 102, for meshing with the gear 205 of the loading assembly 2 to realize the displacement transmission of the loading assembly 2 in the horizontal plane.

[0032] The outer guide rail 102, inner guide rail 103, and rack 104 are respectively fixed to the corresponding base segments by bolts. Since the base segments are detachable and can be spliced, the outer guide rail 102, inner guide rail 103, and rack 104 are processed in sections according to the splicing dimensions of the base segments, and the segments are joined together at the splicing points to ensure that the loading component 2 runs smoothly when moving across segments.

[0033] The loading component 2 can slide within a 360° range along the rounded rectangular slide groove formed by the outer guide rail 102 and the inner guide rail 103 to adjust to any desired horizontal loading position.

[0034] 1.3 Loading Components like Figure 3 As shown, the loading component 2 includes a loading column 201, a vertical movement component 202, an angle adjustment component 203, a loading actuator 204, a gear 205, a slider 206, and a positioning and fixing component 207.

[0035] The loading column 201 is a vertical support structure, with a gear 205 and a slider 206 at its bottom. The gear 205 meshes with the rack 104 on the base assembly 1, and the slider 206 slides with the outer guide rail 102 and the inner guide rail 103. Through the rolling of the gear 205 on the rack 104 and the sliding of the slider 206 on the guide rail, the loading column 201 can move along the groove of the base assembly 1 to the target horizontal position.

[0036] The vertical movement assembly 202 is mounted on the loading column 201 and includes a trapezoidal lead screw and a first servo motor. The output shaft of the first servo motor is fixedly connected to one end of the trapezoidal lead screw via a coupling. The loading actuator 204 is fixedly connected to the lead screw nut of the trapezoidal lead screw. When the first servo motor drives the trapezoidal lead screw to rotate, the lead screw nut drives the loading actuator 204 to rise and fall vertically, thereby adjusting the position of the loading actuator 204 in the vertical direction. The trapezoidal lead screw has a self-locking characteristic; when power is off or the drive stops, the lead screw nut will not slide down due to gravity or load, ensuring test safety.

[0037] The angle adjustment component 203 includes a second servo motor or a hoist, which is fixedly installed on the top of the loading column 201. The output end of the second servo motor or hoist is connected to the front end of the loading actuator 204. When the angle adjustment component 203 is activated, it drives the front end of the loading actuator 204 to rise and fall through its output end, causing the loading actuator 204 to rotate around the connection point between its rear end and the vertical moving component 202, thereby realizing the adjustment of the pitch angle of the loading actuator 204.

[0038] The loading actuator 204 is a hydraulic servo actuator or an electric servo actuator, used to apply tensile and compressive loads to the radar radome test piece 4. The extended end of the loading actuator 204 is provided with a loading connector for connecting to the lever system or directly connecting to the adhesive tape / tension / compression pad.

[0039] The positioning and fixing component 207 is installed at the bottom of the loading column 201. After the loading column 201 is moved into place, the positioning and fixing component 207 locks the loading column 201 in the target loading position. The positioning and fixing component 207 can be a hydraulic locking device or a mechanical locking device, and is fixedly connected to the T-slot or anchor hole on the load-bearing floor by anchor bolts to resist the overturning moment generated during loading.

[0040] A laser displacement rangefinder is installed at the front end of the loading actuator cylinder 204 to collect spatial displacement data of the loading point in real time. A tension / compression sensor is installed on the loading actuator cylinder 204 to collect actual load data of the loading point in real time. The laser displacement rangefinder and the tension / compression sensor are respectively connected to the central controller, feeding back the collected data to the central controller in real time.

[0041] The laser displacement rangefinder uses the laser triangulation or phase method for distance measurement. It emits a laser beam onto the surface of the loading point, receives the reflected light, and calculates the three-dimensional spatial coordinate changes of the loading point, thereby outputting spatial displacement data in real time. The tension and compression sensors are strain gauge or piezoelectric sensors, installed on the piston rod of the loading actuator 204, used to sense the tensile and compressive forces output by the loading actuator 204 in real time and output corresponding electrical signals.

[0042] 1.4 Supported Components like Figure 4 As shown, support component 3 is used to support and fix the radar radome test piece 4, and its specific structure is adapted to the mounting interface form of the radar radome test piece 4. Support component 3 includes support base 301, support platform 302, and test piece interface 303.

[0043] The support base 301 is a frame-type welded structure, fixed to the load-bearing floor with bolts. The support platform 302 is fixedly installed above the support base 301 and fixedly connected to the support base 301 with bolts. The test piece interface 303 is located on the upper surface of the support platform 302, and its shape and size are designed to adapt to the bottom mounting interface of the radar radome test piece 4. The radar radome test piece 4 is fixedly installed on the support assembly 3 through the test piece interface 303.

[0044] Support component 3 can be replaced or adjusted according to the size and structure of radar radome test piece 4 to adapt to the installation requirements of different types of test pieces.

[0045] II. Lever System and Quick-Connect Couplings The radar radome multi-node loading platform also includes a lever system and quick-change connectors.

[0046] The quick-change coupling is a pneumatic or hydraulic quick-change chuck, located between the output end of the loading actuator 204 and the lever system. The quick-change coupling, a pneumatic or hydraulic quick-change chuck, includes jaws and a locking sleeve. The locking sleeve is driven axially by pneumatic or hydraulic pressure, pushing the jaws to radially contract or open, achieving clamping and release at the connection end with the lever system. The lever system is a length-adjustable lever, whose lever arm length is precisely adjusted via a screw adjustment mechanism or a hydraulic pin multi-stage adjustment mechanism. The screw adjustment mechanism includes a screw and a knob. Rotating the screw moves the lever arm axially, changing the position of the lever arm's point of application, thus achieving continuous adjustment of the lever arm length. The hydraulic pin multi-stage adjustment mechanism includes multiple positioning holes along the lever arm length direction and a hydraulically driven pin. By inserting the pin into different positioning holes, multi-stage discrete adjustment of the lever arm length is achieved to adapt to the load amplification or reduction requirements under different working conditions.

[0047] One end of the lever system is connected to the output end of the loading actuator 204 via a quick-change connector. The quick-change connector is a pneumatic or hydraulic quick-change chuck, which allows for quick connection and disconnection between the lever system and the loading actuator 204. The other end of the lever system is connected to an adhesive tape or tension / compression pad adhered to the surface of the radar radome test piece 4, transmitting the tension and pressure output from the loading actuator 204 to the surface of the test piece, thereby loading the test piece.

[0048] The lever system can amplify or reduce the load by changing levers of different lever arm lengths or adjusting the lever arm length according to the load requirements of different working conditions, so as to adapt to the load application needs of different magnitudes. The quick-change coupling can quickly replace the end tooling of the lever system during continuous testing under multiple working conditions without the need for manual disassembly and assembly of bolts, which significantly shortens the working condition switching time.

[0049] III. Usage of the Radar Radar Dome Multi-Node Loading Platform 3.1 Experimental Preparation Phase During the static test of the radar radome, the assembly composition of the base component 1 is first determined according to the load requirements and test piece dimensions of the radar radome. The base components are then assembled and fixed on the load-bearing floor. The support component 3 is then fixed on the load-bearing floor, and the relative positions between the base component 1 and the support component 3 are adjusted and fixed to ensure that the sliding range of the loading component 2 can cover all the loading point positions required for the preset working conditions.

[0050] Subsequently, the radar radome test piece 4 is hoisted onto the test piece interface 303 of the support component 3, and the radar radome test piece 4 is fixedly connected to the test piece interface 303 by bolts or other locking devices.

[0051] The total number of loading components 2 is determined based on the number of maximum load application points required in all preset operating conditions of the radar radome test. Typically, the number of loading components 2 should be equal to or greater than the number of maximum load application points, ensuring that each loading point has a corresponding loading component 2 responsible for applying the load.

[0052] 3.2 Positioning and Adjustment of Loaded Components After determining the total number of loading components 2, each loading component 2 is sequentially installed on the base component 1. For the current working condition, based on the planar coordinates of each loading point, each loading component 2 is moved along the slide groove to its corresponding horizontal position via the guide rails and rack on the base component 1. The trapezoidal lead screw is rotated by the first servo motor of the vertical movement component 202, causing the loading actuator cylinder 204 to rise and fall to the target vertical height. The pitch angle of the loading actuator cylinder 204 is adjusted by the angle adjustment component 203, aligning its loading force line direction with the normal direction of the point of action of the adhesive tape / pressure pad.

[0053] After the position and attitude of each loading component 2 are adjusted, the positioning and fixing component 207 locks each loading component 2 in its current position to prevent displacement during the loading process.

[0054] 3.3 Load Application A lever system is connected to the front end of the loading actuator 204 of each loading component 2. The end of the lever system is connected to an adhesive tape or tension / compression pad adhered to the surface of the radar radome test piece 4. After confirming that all connections are reliable, a loading command is sent through the central controller, and each loading actuator 204 applies tension / compression loads synchronously to complete the static test under the current working condition.

[0055] 3.4 Multi-condition switching After the static test of the current working condition is completed, release the positioning and fixing component 207. If there is a next preset working condition, readjust the horizontal position, vertical position, and / or pitch angle of each loading actuator 204 according to the loading point layout of the next working condition, and relock it through the positioning and fixing component 207. Apply tensile and compressive loads to complete the static test of the next working condition. Repeat the above steps of readjustment, relocking, and application of tensile and compressive loads until all preset working conditions are completed.

[0056] IV. Multi-node loading control method for radar radome multi-node loading platform 4.1 Load Equivalent Treatment Before applying the load, load equivalence processing is performed first. The central controller acquires the uniformly distributed aerodynamic load distribution data and inertial load distribution data of the surface of the radar radome test piece 4. The above data can be obtained through finite element calculation, wind tunnel test or flight load test, and is preset as input parameters in the data storage unit of the central controller.

[0057] Taking a radar radome of a certain type of civil aircraft as an example, its aerodynamic load distribution data under cruise conditions is obtained through CFD calculation, while the inertial load distribution data is calculated based on the mass distribution of the radar radome and the flight overload coefficient. The central controller first performs vector superposition of the uniformly distributed aerodynamic load distribution data and the inertial load distribution data to generate the superimposed total load distribution data.

[0058] Subsequently, adhering to the principle of maintaining constant total load and total moment, the superimposed load distribution data was discretized into multiple concentrated force node data. Specifically, the radome surface was divided into several load application regions, and a representative point was selected within each region as the concentrated force application point. The resultant force of the distributed load within that region was equivalent to that representative point, ensuring that the resultant force and resultant moment of the concentrated forces at all representative points were equal to the resultant force and resultant moment of the original distributed load. Simultaneously, an equivalence relationship between the resultant force and resultant moment of each concentrated force node data and the superimposed load distribution data was established as the basis for subsequent load verification.

[0059] Finally, based on the spatial layout constraints of each loading actuator 204 (i.e., the actual arrangeable position of the loading component 2 on the base component 1), the data of each concentrated force node are vector-synthesized, and the data of multiple concentrated force nodes are merged into the equivalent load vector of each loading component 2, which serves as the target load vector of each loading component 2. The equivalent load vector contains load magnitude and direction information and is the input reference for subsequent decoupling control.

[0060] 4.2 Obtaining the Stiffness Matrix and Constructing the Coupling Inverse Matrix The central controller calls the pre-stored structural stiffness matrix of the test specimen. This structural stiffness matrix characterizes the stiffness properties of the radar radome test specimen 4 at each loading component 2. The structural stiffness matrix can be obtained through finite element simulation or experimental calibration, and is pre-stored in the central controller's database as a data file. This matrix is ​​a multiple-input multiple-output matrix; its diagonal elements reflect the load-displacement relationship of each loading point, while its off-diagonal elements reflect the load coupling relationship between loading points.

[0061] The central controller constructs a multi-input multi-output coupling inverse matrix based on the structural stiffness matrix of the test specimen. This coupling inverse matrix is ​​used to decouple and compensate for load interference during multi-point loading; its construction method involves mathematically inverting the stiffness matrix.

[0062] 4.3 Multi-point load decoupling control During the formal loading process, the central controller acquires the actual force vector data output by each tension and compression sensor in real time, and performs a difference calculation between the actual force vector data and the target load vector to generate the force deviation vector at the current moment. The force deviation vector reflects the deviation between the actual load and the target load at each loading point. This deviation is caused by the load interference effect during multi-point loading (i.e., structural coupling between loading points).

[0063] The central controller inputs the force deviation vector into the coupling inverse matrix for decoupling iterative calculation. Specifically, the force deviation vector is multiplied by the coupling inverse matrix to obtain the independent drive compensation signal for each actuator required to eliminate the current load deviation. This compensation signal is the adjustment amount for the independent drive of each loaded actuator 204, used to counteract the load deviation caused by multi-point load interference.

[0064] 4.4 Driver Instruction Generation and Output The central controller superimposes the independent drive compensation signals onto the basic drive commands of each loading actuator 204 to generate corrected drive signals. These corrected drive signals are then converted from digital to analog to generate real-time drive current commands for each loading actuator 204, which are output to the servo valves of each actuator 204. This controls the synchronous output of tension and compression by each actuator 204, achieving precise loading of the radar radome test piece 4. Through this closed-loop control, the load interference effect during multi-point loading can be effectively eliminated, ensuring that the actual load at each loading point is consistent with the target load.

[0065] 4.5 Orientation Preservation Correction During the process of converting the independent drive compensation signal into a real-time drive current command for each loaded actuator 204 and outputting it to the servo valve of each loaded actuator 204, the central controller synchronously executes the following orientation correction steps.

[0066] When subjected to heavy loads, the radar radome test piece 4 undergoes significant structural deformation, causing spatial displacement at the front end of the loading actuator cylinder 204 (i.e., the loading point). This displacement leads to a deviation of the actual loading force line direction from the preset force line direction. This deviation results in a mismatch between the internal stress distribution of the test piece and the design state, affecting the accuracy of the test results. Therefore, this embodiment employs the following steps to perform real-time closed-loop correction of the force line direction: First, the central controller acquires the preset force line direction vector of each loading component 2 (this vector has been determined during the load equivalence processing stage) and the spatial displacement data output in real time by the laser displacement rangefinder. The laser displacement rangefinder is installed at the front end of the loading actuator cylinder 204, directly facing the point of application of the adhesive tape / tension pad, and measures the three-dimensional spatial coordinate changes of the loading point in a non-contact manner.

[0067] Secondly, the central controller calculates the spatial displacement data to generate the current actual loading point displacement vector, and combines this with the current attitude angle data of each loading actuator 204 to calculate the spatial angle deviation between the current actual force line vector and the preset force line direction vector. This spatial angle deviation reflects the degree of deviation of the actual loading force line from the preset force line direction.

[0068] The central controller compares the spatial angle deviation value with a preset threshold. This preset threshold is set according to the test accuracy requirements and is typically 0.5° to 2°. When the spatial angle deviation value exceeds the preset threshold, the central controller generates position compensation increment signals for the vertical movement component 202 and the angle adjustment component 203 based on the angle deviation value. These position compensation increment signals include the lifting adjustment amount of the vertical movement component 202 and the pitch adjustment amount of the angle adjustment component 203, used to adjust the front end of the loading actuator 204 to a position where the actual force line direction is consistent with the preset force line direction.

[0069] The central controller superimposes the position compensation incremental signal onto the drive command generation terminals of the vertical movement component 202 and the angle adjustment component 203, and controls the vertical movement component 202 and the angle adjustment component 203 to perform corresponding position and attitude fine adjustments, so that the actual force line vector approaches the preset force line direction vector, thereby ensuring that the loading force line direction always meets the test accuracy requirements throughout the loading process.

[0070] 4.6 Multi-condition switching control When it is necessary to switch from the current operating condition to the next preset operating condition, the central controller executes the following multi-condition switching control steps.

[0071] The central controller acquires the target load vectors of each loading component 2 for the current operating condition and the next operating condition, and compares the target load vectors of each loading component 2 for the current operating condition with those for the next operating condition. The target load vectors for the two operating conditions may differ for the following reasons: the number of loading points changes (the next operating condition uses more or fewer loading components 2), the location of the loading points changes (the next operating condition adjusts the arrangement of the loading components), or the loading load value changes (the load amplitude in the next operating condition is different from that in the current operating condition).

[0072] When the target load vector for the next operating condition differs from that for the current operating condition, the central controller automatically generates a quick-change connector switching control signal and a lever arm length adjustment signal based on the target load vector for the next operating condition. The quick-change connector switching control signal drives the quick-change chuck to automatically replace the end tooling of the lever system (e.g., replacing different sizes of tape / pull-pressure pad connectors); the lever arm length adjustment signal drives the lever system's adjustment mechanism to adjust the lever arm length to adapt to the load amplification or reduction requirements of the next operating condition.

[0073] The central controller outputs the quick-change connector switching control signal to the control terminal of the quick-change chuck and the lever arm length adjustment signal to the adjustment mechanism of the lever system. The quick-change chuck and the adjustment mechanism of the lever system execute the corresponding actions to complete the working condition switch. After the switch is completed, the central controller repeats the load equivalence processing, decoupling control and orientation correction steps until all preset working conditions are completed.

[0074] Through the above-mentioned multi-condition switching control, rapid automatic switching between different test conditions is realized, which significantly shortens the test preparation time and improves the efficiency of continuous multi-condition testing.

[0075] In one embodiment of the present invention, taking a radar radome of a civil aircraft as an example, the multi-node loading platform of the present invention is used to conduct static tests on its structural stiffness and strength under limited load and ultimate load. The specific implementation steps are as follows: Step 1: Based on the aerodynamic load distribution and inertial load distribution data of the radar radome, perform load equivalence processing according to the principle of keeping the total load and total moment constant, and obtain the position, load value and direction of the loading force line of each adhesive tape / tension pad action point.

[0076] Step 2: Design the test plan in CATIA 3D design software, determine the splicing composition of base component 1, the number of loading components 2 (8 in total) and the position of each loading component 2, as well as the structural form of support component 3, to form a 3D digital model of the test implementation.

[0077] Step 3: Based on the 3D digital model, assemble and fix the base component 1 on the load-bearing floor, fix the support component 3 on the load-bearing floor, adjust the relative position of the base component 1 and the support component 3 and fix them.

[0078] Step 4: Hoist the radar radome test piece 4 onto the test piece interface 303 of the support component 3, and fix the radar radome test piece 4 to the support component 3 with bolts.

[0079] Step 5: Determine the number (8) and position of loading components 2 based on the 3D digital model. Install each loading component 2 on the base component 1 and adjust it to the target horizontal position. Adjust each loading actuator 204 to the target vertical height through the vertical movement component 202. Adjust each loading actuator 204 to the target pitch angle through the angle adjustment component 203. Then lock each loading component 2 through the positioning and fixing component 207.

[0080] Step 6: Based on the position of the adhesive tape / pull pad, attach the adhesive tape / pull pad to the surface of the radar radome test piece 4, and let it stand at room temperature for 24 hours to allow the adhesive to fully cure.

[0081] Step 7: Connect the output end of each loading actuator 204 to the corresponding tape / pressure pad through the lever system and quick-change coupling.

[0082] Step 8: The central controller controls each loading actuator 204 to synchronously apply tensile and compressive loads to complete the static test under the limited load condition. During the loading process, the orientation correction function monitors and corrects the direction of the loading force line in real time to ensure that the loading accuracy meets the test requirements.

[0083] Step 9: After passing the test, release the positioning and fixing component 207, automatically replace the end tooling of the lever system through the quick-change connector and adjust the lever arm length, adjust the position of the partial loading component 2, and carry out the static test of the next extreme load condition.

[0084] Step 10: Repeat the above working condition switching and loading steps until the static test of all preset working conditions is completed, and the test ends.

[0085] Beneficial effects of the embodiments of the present invention: The base assembly of this invention adopts a structure of four separate, detachable, and detachable base units. This allows for flexible combination based on the size of the radar radome test piece and the number of load application points, meeting the needs of tests of different scales and significantly improving the platform's versatility. The loading assembly, through gear and rack meshing and slider and guide rail sliding cooperation, can move 360° on the base assembly, covering any horizontal loading position and adapting to test requirements with different loading point layouts. The vertical position of the loading actuator is adjusted by the vertical movement assembly, and the pitch angle is adjusted by the angle adjustment assembly, enabling flexible adjustment of the spatial attitude and ensuring that the loading force line direction is consistent with the preset direction, meeting the needs of complex loading conditions. The horizontal movement, vertical lifting, and pitch angle adjustment of the loading assembly are all driven by servo motors, achieving automated control and precise positioning, improving the accuracy and efficiency of loading point positioning, and reducing human error. The support assembly can be replaced or have transition sections added according to the size and structure of the radar radome test piece to adapt to the installation requirements of different types of test pieces, further improving the platform's versatility.

[0086] In the method of use of the present invention, the total number of loading components is determined at once according to the number of maximum load application points required for all preset working conditions. When switching between working conditions, there is no need to add or remove loading components. Only the position and attitude of each loading component need to be adjusted to continue the test. This avoids the tedious operation of rebuilding the loading frame for each working condition in the traditional method, significantly shortens the overall preparation cycle of multi-working-condition test, and improves test efficiency.

[0087] In the control method of the present invention, multi-point load decoupling iterative calculation is performed by the coupling inverse matrix built into the central controller, which can effectively eliminate the load interference effect when multiple loading points are loaded at the same time, so that each loading actuator can independently output precise tensile and compressive loads, and significantly improve the control accuracy of multi-point coordinated loading.

[0088] During the loading process, the spatial displacement data of the loading point is collected in real time by a laser displacement rangefinder, and the angular deviation between the actual force line and the preset force line is calculated by combining the current attitude angle of the loading actuator. When the deviation exceeds the threshold, the position compensation increment signal is automatically generated to drive the vertical movement component and the angle adjustment component to make real-time corrections. This effectively eliminates the offset of the loading force line direction caused by the large deformation of the test piece and ensures the accuracy of the loading force line direction.

[0089] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made within the scope of protection of this patent should still fall within the scope of this patent. Furthermore, the technical features, technical features and technical solutions, and technical solutions in this invention can be freely combined and used.

Claims

1. A multi-node loading platform for a radar radome, characterized in that, include: The base assembly (1) includes multiple detachable and splicable base segments, guide rails and racks (104) disposed on the base segments. The loading component (2) includes a loading column (201), a vertical moving component (202), an angle adjusting component (203), a loading actuator (204), and a positioning and fixing component (207). The loading column (201) is movably mounted on the base assembly (1) via the transmission of the rack (104) and the guidance of the guide rail; The vertical moving component (202) is disposed on the loading column (201) and is used to drive the loading actuator (204) to rise and fall in the vertical direction. The angle adjusting component (203) is disposed on the loading column (201) and is used to adjust the pitch angle of the loading actuator (204). The positioning and fixing component (207) is disposed on the loading column (201) and is used to lock the loading column (201) at the target loading position. Support component (3), the support component (3) includes support base (301), support platform (302) and test piece interface (303), the support base (301) is used to fix to an external load-bearing foundation, the support platform (302) is fixedly set on the support base (301), and the test piece interface (303) is set on the support platform (302) and used to install radar radome test piece (4).

2. The radar radome multi-node loading platform according to claim 1, characterized in that, The base components include a first base component (1011), a second base component (1012), a third base component (1013), and a fourth base component (1014) that are sequentially spliced ​​end to end. The guide rail includes an outer guide rail (102) and an inner guide rail (103), and the outer guide rail (102) and the inner guide rail (103) are respectively fixedly disposed on the upper surface of the base body; The rack (104) is fixedly disposed between the inner guide rail (103) and the outer guide rail (102), and the rack (104) is disposed parallel to the inner guide rail (103) and the outer guide rail (102); The loading column (201) is provided with a gear (205) and a slider (206) at its bottom. The gear (205) meshes with the rack (104), and the slider (206) slides with the outer guide rail (102) and the inner guide rail (103).

3. The radar radome multi-node loading platform according to claim 1, characterized in that, The vertical moving component (202) includes a trapezoidal lead screw and a first servo motor. The output shaft of the first servo motor is fixedly connected to one end of the trapezoidal lead screw. The loading actuator (204) is fixedly connected to the trapezoidal lead screw. The first servo motor drives the loading actuator (204) to move vertically up and down through the trapezoidal lead screw. The angle adjustment component (203) includes a second servo motor or a hoist, which is fixedly installed on the top of the loading column (201). The output end of the second servo motor or the hoist is connected to the front end of the loading actuator (204).

4. The radar radome multi-node loading platform according to claim 1, characterized in that, A laser displacement rangefinder is provided at the front end of the loading actuator (204), and a tension / compression sensor is provided on the loading actuator (204). The laser displacement rangefinder is used to collect spatial displacement data of the loading point in real time, and the tension and compression sensors are used to collect actual load data of the loading point in real time.

5. The radar radome multi-node loading platform according to claim 1, characterized in that, The radar radome multi-node loading platform also includes a lever system and quick-change connectors; One end of the lever system is connected to the output end of the loading actuator (204) via the quick-connect coupling; The quick-change coupling is a pneumatic or hydraulic quick-change chuck.

6. A method of using a multi-node loading platform for a radar radome, wherein the method employs the multi-node loading platform for a radar radome as described in any one of claims 1 to 5, characterized in that... Includes the following steps: The base assembly (1) and the support assembly (3) are fixed on the external load-bearing foundation, and the relative positions of the base assembly (1) and the support assembly (3) are adjusted. The radar radome test piece (4) is installed on the test piece interface (303) of the support assembly (3); The total number of loading components (2) is determined based on the number of maximum load application points required in all preset operating conditions of the radar radome test. Repeat the following steps until the static test for all preset working conditions is completed: The horizontal position of each loading component (2) is adjusted by the guide rail and rack on the base assembly (1), the vertical position of the loading actuator (204) is adjusted by the vertical moving component (202), and the pitch angle of the loading actuator (204) is adjusted by the angle adjusting component (203). Each loading component (2) is locked by the positioning and fixing component (207); After applying tensile and compressive loads through each of the loading actuators (204), the positioning and fixing components (207) are released after completing the static test of the current working condition.

7. A multi-node loading control method, used in the radar radome multi-node loading platform according to any one of claims 1 to 5, characterized in that, Includes the following steps: Obtain the uniform aerodynamic load distribution data on the surface of the radar radome test piece (4), and generate the target load vector of each loading component (2) based on the uniform aerodynamic load distribution data. Obtain the structural stiffness matrix of the test specimen, and construct a multi-input multi-output coupled inverse matrix based on the structural stiffness matrix of the test specimen; Acquire the actual force vector data output by each tension and compression sensor, and perform a difference calculation between the actual force vector data and the target load vector to generate the force deviation vector at the current moment; The force deviation vector is input into the coupling inverse matrix for decoupling iterative calculation to obtain the independent drive compensation signal of each loaded actuator (204) after eliminating multi-point load interference; The independent drive compensation signal is converted into a real-time drive current command for each loaded actuator (204), and the real-time drive current command is output to the servo valve of each loaded actuator (204).

8. The multi-node loading control method according to claim 7, characterized in that, The target load vector for each loading component (2) is generated based on the uniformly distributed aerodynamic load distribution data, including: Obtain the uniformly distributed aerodynamic load distribution data and inertial load distribution data on the surface of the radar radome test piece (4); The uniformly distributed aerodynamic load distribution data and the inertial load distribution data are vector-superimposed to generate superimposed load distribution data; Based on the principle that the total load and total moment remain unchanged, the superimposed load distribution data is discretized into multiple concentrated force node data, and the equivalent relationship between the resultant force and resultant moment between each concentrated force node data and the superimposed load distribution data is established. Based on the spatial layout constraints of each loading actuator (204), the data of each concentrated force node are vector synthesized, and the data of multiple concentrated force nodes are merged into the equivalent load vector of each loading component (2), which is used as the target load vector of each loading component (2).

9. The multi-node loading control method according to claim 7, characterized in that, The process of converting the independent drive compensation signal into a real-time drive current command for each loaded actuator (204) and outputting it to the servo valve of each loaded actuator (204) also includes the following steps: Obtain the preset force line direction vector of each loading component (2) and the spatial displacement data output by the laser displacement rangefinder; The spatial displacement data is calculated to generate the current actual loading point displacement vector, and combined with the current attitude angle data of each loading actuator (204), the spatial angle deviation value between the current actual force line vector and the preset force line direction vector is generated. When the spatial angle deviation value exceeds a preset threshold, position compensation incremental signals for the vertical movement component (202) and the angle adjustment component (203) are generated based on the angle deviation value. The position compensation increment signal is superimposed on the drive command generation terminals of the vertical movement component (202) and the angle adjustment component (203).

10. The multi-node loading control method according to claim 7, characterized in that, Also includes: When switching to preset operating conditions, the following steps are included: Obtain the target load vectors of each loading component (2) under the current working condition and the next working condition respectively, and compare the target load vectors of each loading component (2) under the current working condition with the target load vectors of each loading component (2) under the next working condition. When the target load vector of the next working condition is different from the target load vector of the current working condition, a quick-connect coupling switching control signal and a lever arm length adjustment signal of the lever system are generated according to the target load vector of the next working condition. The quick-change connector switching control signal is output to the control end of the quick-change chuck, and the lever arm length adjustment signal is output to the adjustment mechanism of the lever system.

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