Elastic drum deflection inversion calculation method and device based on strain analysis

Abstract

The invention belongs to the technical field of deflection calculation, and relates to an elastic winding drum deflection inversion calculation method and device based on strain analysis. The method comprises the following steps: performing strain analysis on an elastic drum to obtain elastic drum fixed end strain data and elastic drum free end deflection data; generating a strain and deflection data sample set of the elastic winding drum according to the strain data of the fixed end of the elastic winding drum and the deflection data of the free end of the elastic winding drum; according to the strain and deflection data sample set, obtaining a polynomial relationship between the strain and the deflection, and writing the polynomial relationship into a matrix form to obtain a matrix relationship between the strain and the deflection; calculating coefficient vectors of the matrix relationship under different orders, and determining the order of a polynomial relationship in combination with an akaike information criterion to obtain a polynomial equation of strain and deflection; and according to the polynomial equation and the obtained strain data, carrying out inversion calculation to obtain the free end deflection of the elastic winding drum. According to the invention, deflection inversion calculation can be carried out.

Description

Technical Field

[0001] The present application relates to the technical field of deflection calculation, and in particular to a method and device for inverse calculation of elastic drum deflection based on strain analysis. Background Art

[0002] With the rapid development of my country's deep space exploration and on-orbit service technologies, satellite-borne extension mechanisms are moving towards large-scale and high-precision. As the core component of the new generation of reel-type extension mechanisms, the elastic reel can accurately extend the scientific payloads (including but not limited to magnetometers, optical payloads, and communication antennas) carried at the end to the predetermined working position. This feature can effectively avoid electromagnetic interference and mechanical vibration of the satellite platform itself, and plays a key role in improving the quality of space exploration data. Among them, the elastic reel can be regarded as a cantilever beam structure in the service state. The deflection of its free end is the core parameter that characterizes the shape and position accuracy of the mechanism. It directly determines the positioning accuracy of the payload terminal and is an important technical indicator that affects the effectiveness of on-orbit detection.

[0003] In existing technologies, the measurement of the free end deflection of cantilever beam structures in current engineering practice mainly relies on contact detection methods (such as micrometers and dial indicators), which have the following disadvantages: 1) Existing methods require mechanical contact to obtain surface displacement, but the additional load introduced during the measurement process will significantly change the actual stress state of the measured component, resulting in systematic deviations in the measurement data.

[0004] 2) Existing deflection curve measurement typically uses a discrete point table method, where deflection data is collected point by point at pre-set measurement points and then the deflection curve shape is reconstructed through numerical fitting. This method not only suffers from low measurement efficiency and the introduction of additional loads, but also has insufficient spatial resolution, making it difficult to meet the requirements of high-precision deformation detection.

[0005] 3) The actual service environment of the elastic reel is the microgravity environment in space, and the influence of the gravity field during ground testing will significantly change the structural mechanical response, which makes the traditional measurement method limited in verifying the consistency between the ground and the sky.

[0006] 4) It is not possible to directly perform contact measurement operations on the elastic reel during on-orbit operation or during ground simulation tests such as aging test chambers and thermal vacuum test chambers.

[0007] However, non-contact solutions based on optical measurement face challenges from complex factors such as space radiation interference, thermal deformation, and the inability of sensors to withstand extreme conditions.

[0008] In addition, since the elastic drum has a special spirally wound laminated structure, the applicability of traditional theoretical models in deriving the free end deflection theory is limited. Finite element simulation calculations are time-consuming and difficult to support high-precision inversion requirements.

[0009] Therefore, how to establish an elastic drum deflection detection method that has the capabilities of non-contact measurement, equivalent simulation of the earth and sky environment, and adaptability to complex working conditions has become a key bottleneck in breaking through the engineering application of the new generation of space extension rod mechanisms. Summary of the Invention

[0010] Based on this, it is necessary to provide a method and device for inverse calculation of elastic drum deflection based on strain analysis to address the above technical problems, which can perform inverse calculation of deflection.

[0011] A strain analysis-based inverse calculation method for elastic drum deflection includes: Perform strain analysis on the elastic roll to obtain strain data of the fixed end of the elastic roll and deflection data of the free end of the elastic roll; Generate a sample set of strain and deflection data of the elastic roll according to the strain data of the fixed end of the elastic roll and the deflection data of the free end of the elastic roll; According to the strain and deflection data sample set, the polynomial relationship between strain and deflection is obtained, and the polynomial relationship is written into a matrix form to obtain the matrix relationship between strain and deflection; The coefficient vectors of the matrix relationship at different orders are calculated, and the order of the polynomial relationship is determined by combining the Akaike information criterion to obtain the polynomial equations of strain and deflection. Based on the polynomial equation and the obtained strain data, an inverse calculation is performed to obtain the free end deflection of the elastic drum.

[0012] In one embodiment, obtaining the strain data of the fixed end of the elastic roll includes: Fix the end of the elastic roll with a larger diameter to the fixture as the fixed end, and the other end as the free end; Return the initial deflection of the free end to zero; A full-bridge strain gauge attached to the extreme strain value is used to collect the strain data under the free end deflection gradient loading to obtain the strain data of the fixed end of the elastic drum. .

[0013] In one embodiment, obtaining the deflection data of the free end of the elastic roll includes: The connection between the elastic reel and the fixture is taken as the reference plane, and the deflection when the laser displacement meter faces the reference plane is taken as the deflection zero position reference; Return the initial deflection of the free end to zero; A laser displacement meter is installed just above the elastic drum and can move along the length of the elastic drum to collect the deflection data of the free end under the gradient loading of the deflection, and the deflection data of the free end of the elastic drum is obtained. .

[0014] In one embodiment, a polynomial relationship between strain and deflection is obtained based on a sample set of strain and deflection data, including:

[0015] Where, is the deflection data, is the strain data, is the order of the polynomial relation, is the undetermined coefficient.

[0016] In one embodiment, the polynomial relationship is written in matrix form to obtain a matrix relationship between strain and deflection, including:

[0017] in,

[0018] Where, is the design matrix, is the observation vector, is the coefficient vector, is the number of sample groups in the strain and deflection data sample set. In one embodiment, the coefficient vectors of the matrix relationship at different orders are calculated, and the order of the polynomial relationship is determined in combination with the Akaike information criterion to obtain the polynomial equation of strain and deflection, including: Compute the coefficient vectors of matrix relations at different orders:

[0019] Where, for The transpose of Combined with Akaike's information criterion, the order of the polynomial relationship is determined to be the minimum value without the occurrence of singular matrices, and the polynomial equations of strain and deflection are obtained.

[0020] A device for calculating the deflection of an elastic drum based on strain analysis and inverse calculation thereof adopts a method for calculating the deflection of an elastic drum based on strain analysis, comprising: a base assembly, a gantry assembly, a motion control assembly, a motion guide assembly, an optical measurement assembly, a gravity balance assembly, a strain monitoring assembly, an elastic drum, and an elastic drum fixture; The base assembly is a flat plate structure and serves as a reference platform for the device; The gantry assembly is arranged on the base assembly, including a horizontal beam and two vertical beams, the ends of the horizontal beam are respectively connected to a vertical beam and are arranged parallel to the base assembly, so that the base assembly and the gantry assembly together form a "mouth" shaped frame structure; The motion control assembly is arranged on the horizontal beam and is connected to the motion guide assembly to drive the motion guide assembly; The motion guide assembly is provided on the horizontal beam to drive the optical measurement assembly; The optical measurement assembly is arranged on the motion guide assembly, so that the optical measurement assembly moves along the length direction of the elastic roll under the drive of the motion guide assembly and collects deflection data of the free end of the elastic roll; The gravity balance component is arranged on the base component to realize the zero return of the initial deflection of the free end of the elastic reel and adjust the deflection of the free end of the elastic reel together with the optical measurement component; The strain monitoring component collects strain data of the fixed end of the elastic drum by attaching a strain gauge to the strain extreme value area on the outer circumference of the elastic drum; The elastic reel is used as a detection object, and the end of the elastic reel with a larger diameter is fixed on the elastic reel fixture and serves as a fixed end, while the other end is a free end.

[0021] In one embodiment, the motion guide assembly includes: a base plate, a side plate, a partition plate, a linear guide rail, a ball screw, a motion slide, and a stepper motor; The bottom plate is arranged on the horizontal beam along the length direction of the horizontal beam; There are two side panels, which are respectively vertically arranged at both ends of the bottom plate; The partition is vertically arranged on the bottom plate and between the two side plates; There are two linear guide rails, which are arranged in parallel and spaced apart on both sides of the ball screw; the linear guide rail and the ball screw are both arranged between the partition and a side plate, one corresponding end is connected to the partition, and the other corresponding end passes through the motion slide and is connected to a side plate; The stepping motor is arranged between the partition plate and the other side plate.

[0022] In one embodiment, the gravity balancing assembly includes: a lifting platform, a lifting slider, a balancing bracket, and an adjusting screw; The lifting platform is vertically arranged on the base assembly at a position corresponding to the midpoint of the elastic reel; The lifting slider is arranged on the lifting platform and has a travel along the length direction of the lifting platform; The balancing bracket is provided on the lifting slider and is linked with the lifting slider to realize the zero return of the initial deflection of the free end of the elastic drum and adjust the deflection of the free end of the elastic drum together with the optical measurement component; The adjusting screw is arranged on the lifting slider to adjust the position of the lifting slider on the lifting platform.

[0023] In one embodiment, the strain monitoring assembly includes: a primary strain gauge and an auxiliary strain gauge; The main strain gauge is provided on the lower outer edge of the first spiral turn from the fixed end to the free end of the elastic drum, and the auxiliary strain gauge is provided on the lower outer edge of the second spiral turn from the fixed end to the free end of the elastic drum; The main strain gauge and the auxiliary strain gauge are both connected to an external signal conditioning circuit.

[0024] The above-mentioned elastic drum deflection inversion calculation method based on strain analysis constructs an asymmetric polynomial transfer function model based on the fixed end strain data and the free end deflection data measured by the laser displacement meter, adopts the recursive least squares method for parameter estimation, combines the AIC criterion to achieve model order optimization, and establishes a high-precision inversion calculation model with the matrix pathological degree as a constraint. With the help of this model, when only the strain data of the fixed end of the elastic drum can be obtained, the free end deflection can be accurately calculated. It is particularly suitable for indirect monitoring of the free end deflection of the elastic drum, the core component of the drum-type extension rod mechanism.

[0025] The above-mentioned elastic roll deflection inversion calculation device based on strain analysis includes a gravity balance component, an optical measurement component and a motion guide component, etc. It simulates the microgravity environment through the gravity compensation mechanism, uses a laser displacement meter to eliminate the influence of additional loads, and combines with the motion guide component to realize non-contact deflection curve scanning. The motion guide component, the optical measurement component and the motion control component can realize the deflection curve output of the elastic roll under different strains, that is, different free end deflections; through the gravity balance component and the optical measurement component, the non-contact zero calibration of the initial deflection of the elastic roll is realized; combined with the precision linear guide rail and the high-precision laser displacement meter, the authenticity and integrity of the deflection curve data are ensured; through the componentized architecture of standardized aluminum alloy profiles and quick-release interfaces, it supports rapid reconstruction and function expansion, is compatible with the testing requirements of elastic rolls of different specifications, and significantly reduces the equipment modification cost and debugging cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 1 is a flow chart of a method for inverse calculation of elastic drum deflection based on strain analysis in one embodiment; Figure 2 Schematic diagram of an architecture of an elastic drum deflection inversion calculation method based on strain analysis in one embodiment; Figure 3 It is a structural diagram of an elastic reel; Figure 4 3D schematic diagram of the overall structure of an elastic drum deflection inversion calculation device based on strain analysis in one embodiment; Figure 5 A side view of a device for inverse calculation of elastic drum deflection based on strain analysis in one embodiment; Figure 6Schematic diagram of the structure of a motion guide component of an elastic drum deflection inversion calculation device based on strain analysis in one embodiment; Figure 7 Schematic diagram of the structure of a gravity balance component of an elastic drum deflection inversion calculation device based on strain analysis in one embodiment; Figure 8 A bottom view of the strain gauge distribution of an elastic drum deflection inversion calculation device based on strain analysis in one embodiment; Figure 9 is a function curve diagram of a strain-deflection transfer model in a specific embodiment; Figure 10 is a diagram for evaluating the generalization capability of the strain-deflection transfer model in a specific embodiment; Figure 11 FIG. 4 is a graph of a measured deflection curve in a specific embodiment.

[0027] Reference numerals: Base assembly 1; Gantry assembly 2; horizontal beam 21, vertical beam 22; Motion guide assembly 3: bottom plate 31, side plate 32, partition 33, linear guide rail 34, ball screw 35, motion slide 36, stepping motor 37; Gravity balance assembly 4; lifting platform 41, lifting slider 42, balance bracket 43, adjustment screw 44; Optical measurement component 5; laser displacement meter 51, fixture 52; Motion control component 6; Strain monitoring component 7; main strain gauge 71, auxiliary strain gauge 72; Elastic reel 8; Elastic reel clamp 9. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in this application without creative work are within the scope of protection of this application.

[0029] In addition, the terms "first," "second," and so on, used in this application are for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, "multiple groups" means at least two groups, such as two groups, three groups, and so on, unless otherwise specifically defined.

[0030] In this application, unless otherwise specified or limited, the terms "connect," "fix," etc. should be understood in a broad sense. For example, "fix" can mean a fixed connection, a detachable connection, or an integral connection; it can mean a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean internal communication between two elements or an interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0031] In addition, the technical solutions between the various embodiments of the present application can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0032] This application provides a method for inverse calculation of elastic drum deflection based on strain analysis, such as Figure 1 and Figure 2 The flowchart shown, in one embodiment, includes: Step 101 : performing strain analysis on the elastic drum to obtain strain data of the fixed end of the elastic drum and deflection data of the free end of the elastic drum.

[0033] Specifically: The strain data of the fixed end of the elastic roll are obtained including: Perform strain analysis on the elastic roll. Fix the end with the larger diameter of the elastic roll to the fixture and use it as the fixed end, while the other end is used as the free end. Returning the initial deflection of the free end to zero (how to return it to zero belongs to the prior art); A full-bridge strain gauge is attached to the outer edge of the elastic drum at the strain extreme value, and the full-bridge strain gauge is connected to the data acquisition device to collect the strain data under the free end deflection gradient loading (specifically: the host computer software performs zero point calibration and records it as the strain zero reference ε0=0, then increases the free end deflection gradient n Each time, the corresponding fixed end strain data is collected and uploaded to the host computer), and the fixed end strain data of the elastic roll is obtained. .

[0034] The deflection data of the free end of the elastic drum are obtained including: The direction from the fixed end to the free end of the elastic roll is the X-axis, and the fixed end coordinate is the origin (i.e. the fixed end coordinate is 0) to construct a coordinate system. The coordinate of the free end of the elastic roll is set as the length of the elastic roll L, and the coordinate of the detection point is obtained. x j satisfy The connection between the elastic drum and the fixture is taken as the reference plane, and the deflection of the high-precision laser displacement meter (installed above the elastic drum) facing the reference plane is taken as the deflection zero reference, that is, the laser displacement meter moves to x j =0, reset the reading to zero, record it as δ 0=0, set as deflection zero reference; Move the laser displacement meter to x j =L, to adjust the initial deflection of the free end of the elastic reel until the initial deflection of the free end is returned to zero, that is, δ (L)=0; A laser displacement meter is installed just above the elastic drum and can move along the length of the elastic drum to increase the deflection gradient of the free end. n Second, collect the deflection data of the free end under gradient loading to obtain the deflection data of the free end of the elastic roll .

[0035] In this step, the attachment position of the full-bridge strain gauge is the extreme strain value when the fixed end of the elastic drum is subjected to a uniformly distributed load. Specifically, it is positioned through ABAQUS static simulation and is located at the lower outer edge of the first and second turns of the spiral from the fixed end to the free end.

[0036] Step 102 : generating a sample set of strain and deflection data of the elastic roll according to the strain data of the fixed end of the elastic roll and the deflection data of the free end of the elastic roll.

[0037] In this step, the strain-deflection data at the same timestamp are composed into a sample set {(εᵢ, δᵢ) | i=1,2,...,n}.

[0038] Step 103 : obtaining a polynomial relationship between strain and deflection based on the strain and deflection data sample set, and writing the polynomial relationship into a matrix form to obtain a matrix relationship between strain and deflection.

[0039] Specifically: Based on the strain and deflection data sample set, the generalized polynomial relationship between strain and deflection containing the unknown coefficients is obtained:

[0040] Where, is the deflection data, is the strain data, is the order of the polynomial relation, is the coefficient to be determined; Writing the polynomial relationship in matrix form, we get the matrix relationship between strain and deflection:

[0041] in,

[0042] Where, is the design matrix, is the observation vector, is the coefficient vector, is the number of sample groups in the strain and deflection data sample set. In this step, the polynomial relationship between strain and deflection and the matrix relationship between strain and deflection are determined.

[0043] Step 104 , calculating the coefficient vectors of the matrix relationship at different orders, and combining the Akaike information criterion to determine the order of the polynomial relationship, and obtaining the polynomial equation of strain and deflection.

[0044] Specifically: According to the recursive least squares method, the coefficient vectors of the matrix relationship at different orders are calculated through the normal equation:

[0045] Where, for The transpose of Combined with the Akaike Information Criterion (AIC criterion), assuming that the error obeys the normal distribution, satisfying , where SSE is the sum of squared errors, n is the sample size, and to avoid overfitting, k Every time it increases by 1, The degree of pathological condition is judged, and finally the order of the polynomial relationship is determined to be the minimum value without the occurrence of singular matrix (i.e. k for is not close to the minimum of the singular matrix), and obtains the polynomial equations for strain and deflection.

[0046] In this step, the polynomial equations for strain and deflection are determined.

[0047] Step 105 : performing an inverse calculation based on the polynomial equation and the acquired strain data to obtain the free end deflection of the elastic drum.

[0048] Specifically: According to the polynomial equation and the obtained strain data, the obtained strain data is substituted into the established polynomial equation, and an inversion calculation is performed to obtain the free end deflection of the elastic drum.

[0049] In this step, how to perform inversion calculation based on the polynomial equation and the acquired strain data belongs to the existing technology.

[0050] In this example, the coefficient of determination R² is calculated to evaluate the goodness of fit:

[0051] in, is the model prediction value, is the mean deflection.

[0052] The above-mentioned elastic drum deflection inversion calculation method based on strain analysis constructs an asymmetric polynomial transfer function model based on the fixed end strain data and the free end deflection data measured by the laser displacement meter, adopts the recursive least squares method for parameter estimation, combines the AIC criterion to achieve model order optimization, and establishes a high-precision inversion calculation model with the matrix pathological degree as a constraint. With the help of this model, when only the strain data of the fixed end of the elastic drum can be obtained, the free end deflection can be accurately calculated. It is especially suitable for scenarios where it is inconvenient to directly obtain the free end deflection, such as the indirect monitoring of the free end deflection of the elastic drum, the core component of the drum-type extension rod mechanism.

[0053] This application constructs a strain-deflection transfer model through the fixed-end strain data and the free-end deflection data. Based on the fixed-end strain data, the constructed strain-deflection transfer model can realize indirect measurement of the free-end deflection, and can output the elastic roll deflection curve under different strains, providing data and theoretical support for the free-end deflection inversion analysis, deformation analysis and theoretical derivation of the deflection curve of the special spirally wound stacked structure of the elastic roll of the detection object; at the same time, the gravity field equivalent compensation mechanism is introduced to effectively eliminate the mechanical differences between the ground test environment and the actual working conditions in space, providing a complete ground-to-space integrated solution for the deflection detection of the elastic roll.

[0054] The present invention is applicable to conventional ground test environments and supports the replacement of high temperature / low temperature strain gauges to adapt to the elastic drum deflection monitoring in complex scenarios such as thermal vacuum test chambers. It has high precision (achieves 10 -6 The advantages of this system include high-level measurement (i.e., microstrain measurement), scalability (deflection measurement in special environments can be achieved by replacing strain gauges), and global consistency (usability in zero-gravity environments). For example, by changing the model of the full-bridge strain gauge, such as replacing it with a high-temperature or low-temperature strain gauge, strain measurement can be achieved in different special environmental conditions such as aging test chambers and thermal vacuum test chambers, thereby indirectly obtaining the free end deflection of the elastic roll.

[0055] It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. In addition, Figure 1At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0056] This application also provides an elastic drum deflection inversion calculation device based on strain analysis, such as Figures 3 to 8 As shown, in one embodiment, a strain analysis-based elastic drum deflection inversion calculation method is adopted, including: a base component 1, a gantry component 2, a motion control component 6, a motion guide component 3, an optical measurement component 5, a gravity balance component 4, a strain monitoring component 7, an elastic drum 8 and an elastic drum clamp 9.

[0057] The base assembly 1 is a flat plate structure and serves as a reference platform for the device. The base assembly is made of standard aluminum alloy profiles, specifically two pieces of standard aluminum alloy profiles spliced ​​together by high-strength bolts.

[0058] The gantry assembly 2 is mounted on the base assembly and includes a horizontal beam 21 and two vertical beams 22. Each end of the horizontal beam is connected to a vertical beam and arranged parallel to the base assembly, forming a "U"-shaped frame structure with the base assembly. Specifically, the gantry assembly is composed of three standard aluminum alloy profiles assembled with right-angle connectors to form a portal frame structure. The gantry assembly and base assembly are secured with seismic connectors to ensure parallelism between the gantry assembly's horizontal beam and the base assembly.

[0059] The motion control component 6 is arranged on the horizontal beam and is connected to the motion guide component. Specifically, a stepper motor drive system can be used to drive the motion guide component by controlling the speed and direction of the stepper motor, thereby controlling the axial movement speed and precise positioning of the motion slide, realizing the motion slide stroke control, and uploading the motion slide position data to the host computer in real time, thereby realizing the precise positioning of the optical measurement component.

[0060] The motion guide assembly 3 is arranged on the horizontal beam to drive the optical measurement assembly. The motion guide assembly is a double-track linear module, including: a base plate 31, a side plate 32, a partition 33, a linear guide 34, a ball screw 35, a motion slide 36 and a stepper motor 37; the base plate 31 is arranged on the horizontal beam along the length direction of the horizontal beam; there are two side plates 32 and they are respectively arranged vertically at both ends of the base plate; the partition 33 is arranged vertically on the base plate and between the two side plates; the linear guide 34 is a precision linear guide, there are two of them, and they are arranged parallel and spaced on both sides of the ball screw 35; the linear guide and the ball screw are connected. The screw rods are arranged between the partition and a side plate, with one corresponding end connected to the partition and the other corresponding end connected to a side plate after passing through the motion slide; the motion slide 36 is installed on the linear guide rail and the ball screw; the stepper motor 37 is arranged between the partition and the other side plate, and is connected to the motion control component to drive the ball screw to rotate, thereby driving the motion slide to move along the length direction of the ball screw, and then driving the optical measurement component to move, thereby realizing the deflection reference positioning and non-contact measurement of the elastic reel of the detection object.

[0061] The optical measurement assembly 5 is mounted on the motion guide assembly, allowing it to move along the length of the elastic roll under the motion guide assembly's drive and collect deflection data at the free end of the elastic roll. The optical measurement assembly includes a high-precision laser displacement meter 51 secured to the motion slide via a quick-release clamp 52 for non-contact deflection data collection.

[0062] The gravity balance assembly 4 is mounted on the base assembly to, in conjunction with the optical measurement assembly, reset the initial deflection of the free end of the elastic roll to zero and adjust the deflection of the free end of the elastic roll. The gravity balance assembly comprises a lifting platform 41, a lifting slider 42, a balancing bracket 43, and an adjusting screw 44. The lifting platform 41 is vertically mounted on the base assembly at a position corresponding to the midpoint of the elastic roll. The lifting slider 42 is mounted on the lifting platform and has a travel length along the lifting platform. The balancing bracket 43 is a plate-like structure with one end rolled up and mounted on the lifting slider. The balancing bracket 43 is linked to the lifting slider to, in conjunction with the optical measurement assembly, reset the initial deflection of the free end of the elastic roll to zero and adjust the deflection of the free end of the elastic roll. The adjusting screw 44 is mounted on the lifting slider to adjust the position of the lifting slider on the lifting platform, thereby cooperating with the optical measurement assembly to reset the initial deflection of the free end of the elastic roll to zero and adjust the deflection of the free end of the elastic roll, thereby obtaining different strain and deflection data. That is to say, according to the uniformly distributed load stress characteristics of the cantilever beam structure, with the fixed end of the elastic reel as the reference, the gravity balance component is located at 1 / 2 of the length L of the elastic reel in the length direction of the elastic reel. The elastic reel is supported by a lifting mechanism to offset gravity, thereby simulating a microgravity environment. This component is used to adjust the deflection of the free end of the elastic reel to zero.

[0063] The strain monitoring assembly 7 collects strain data at the extreme strain value of the elastic drum's fixed end by attaching strain gauges to the extreme strain value area on the outer circumference of the elastic drum. The strain monitoring assembly includes a main strain gauge 71 and an auxiliary strain gauge 72. The main strain gauge and the auxiliary strain gauge are full-bridge strain gauges to form a full-bridge strain gauge array. Both are attached to the extreme strain value area on the outer circumference of the elastic drum by curing epoxy resin glue, and the signal is processed by a 24-bit data acquisition card. The main strain gauge 71 is located at the lower outer edge of the first spiral turn from the fixed end to the free end of the elastic drum to collect strain data at the fixed end of the elastic drum. The auxiliary strain gauge 72 is located at the lower outer edge of the second spiral turn from the fixed end to the free end of the elastic drum to ensure that the main strain gauge is attached to the extreme strain value. The strain measured by the auxiliary strain gauge is less than the strain measured by the main strain gauge throughout the entire process. The main strain gauge and the auxiliary strain gauge are both connected to an external signal conditioning circuit.

[0064] The elastic drum 8 is a spirally wound laminated structure. As the detection object, the end with a larger diameter is fixed on the elastic drum fixture and serves as a fixed end, and the other end is a free end.

[0065] The elastic reel clamp 9 is provided on the base assembly and is used for fixing and clamping the elastic reel.

[0066] Specific usage methods include: Step 1: Device Assembly and Initial Calibration 1. Assemble the base assembly 1 and the gantry assembly 2 through the seismic connectors. Use a laser level to calibrate the parallelism between the horizontal beam and the base to ensure measurement accuracy. 2. Install the precision linear guide 34, debug the ball screw 35 (lead 5mm) and the stepper motor 37, and verify that the repeatability of the motion slide 36 reaches ±0.01mm; 3. Clamp the elastic roll 8 to the elastic roll fixture 9, fix the laser displacement meter 51 to the moving slide 36 through the fixture 52, align it with the reference surface of the fixed end of the elastic roll, and reset the reading of the laser displacement meter 51 to zero; 4. Adjust the position of the moving slide 36 until the laser displacement meter 51 is aligned with the reference surface of the free end of the elastic roll; 5. Install the gravity balance assembly 4, position the compensation fulcrum to X = L / 2 ± 1 mm, and adjust the adjusting screw 44 to return the free end deflection reading to zero (error ≤ 0.5 mm).

[0067] Step 2: Deployment of the strain monitoring system 6. Clean the outer surface of the elastic roller 8 and press Figure 8 Paste the full-bridge strain gauge at the position shown and use epoxy resin glue to cure for 24 hours; 7. Connect the strain gauge wires to the signal conditioning circuit and connect to the 24-bit data acquisition card.

[0068] Step 3: Zero reference establishment 8. Control the motion slide 36 through the motion control component 6 to perform a bidirectional full-stroke scan (X=L→X=0→X=L), verify that the full-stroke reading fluctuation of the laser displacement meter 51 is less than ±0.5mm, and return the strain data to zero, setting it as the strain zero reference.

[0069] Step 4: Hierarchical loading and data collection 9. Lower the height of the lifting mechanism balance bracket 43 in a gradient manner. Use the optical measurement component 5 to monitor the free end deflection in real time, and use the strain monitoring component 7 to monitor the fixed end strain in real time. After the deflection and strain data readings stabilize, combine the strain-deflection data with the same timestamp into a sample set {(εᵢ, δᵢ) | i=1,2,...,n} until the deflection threshold is reached. δ max , that is, the elastic reel bears all gravity, and the gravity balance component is disengaged from the elastic reel; 10. After the loading readings at each level are stable and the above sample set is generated, a bidirectional scan (X=L→X=0→X=L) is performed to synchronously collect the X-axis coordinates of the motion slide 36 ( x ) and laser displacement meter readings ( y ), so that the above ( x , y )Data constitutes the sample set {( x j , y j ) | j =1,2,..., m}, according to the collected x , y Coordinates, with x The data is the horizontal axis, y The data are connected into a smooth curve to generate the deflection curve of the elastic roll 8 under different strains, which can be output in total. n The output of the deflection curve can provide data and theoretical support for the inversion analysis of the free end deflection of the elastic reel 8 of the detection object, deformation analysis, and theoretical derivation of the deflection curve of the special spirally wound laminated structure of the elastic reel, and has good application prospects.

[0070] Step 5: Data Verification and Error Analysis 11. The strain-deflection mapping model was established using the least squares method to obtain a polynomial equation, and the coefficient of determination R² was used to evaluate the goodness of fit.

[0071] The above-mentioned elastic roll deflection inversion calculation device based on strain analysis includes a gravity balance component, an optical measurement component and a motion guide component, etc. It simulates the microgravity environment through the gravity compensation mechanism, uses a laser displacement meter to eliminate the influence of additional loads, and combines the motion guide component to realize non-contact deflection curve scanning. The motion guide component, the optical measurement component and the motion control component can realize the deflection curve output of the elastic roll under different strains, that is, different free end deflections; through the gravity balance component and the optical measurement component, the non-contact zero calibration of the initial deflection of the elastic roll is realized; combined with the precision linear guide rail and the high-precision laser displacement meter, the authenticity and integrity of the deflection curve data are ensured; through the componentized architecture of standardized aluminum alloy profiles and quick-release interfaces, it supports rapid reconstruction and function expansion, is compatible with the testing requirements of elastic rolls of different specifications, and significantly reduces the equipment modification cost and debugging cycle; in addition, the device of the present application has a gravity compensation function, and can realize real-time sampling and full-stroke measurement.

[0072] The specific definitions of a strain-analysis-based elastic drum deflection inversion calculation device can be found in the aforementioned definitions of a strain-analysis-based elastic drum deflection inversion calculation method and are not further elaborated here. Each module in the aforementioned device can be implemented in whole or in part via software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in hardware form, or stored in a computer device memory in software form, allowing the processor to call and execute the corresponding operations of each module.

[0073] In a specific embodiment, the length of the elastic roll is L=950 mm, and a set of typical strain-deflection sample sets are obtained as shown in Table 1 below.

[0074] Table 1: Typical strain-deflection sample set

[0075] Taking the sample set data in Table 1 as an example, the results of constructing the strain-deflection transfer function model are as follows.

[0076] The constructed matrix relationship is:

[0077] in,

[0078] When k is 1, the AIC value is -2.4253; when k is 2, the AIC value is -30.4228; when k ≥ 3, The matrix is ​​close to a singular matrix, and the numerical stability when solving the equation system is poor; therefore, k=2 is taken, and the coefficient vector of the strain-deflection transfer function model in this embodiment is finally obtained as:

[0079] So the strain-deflection transfer function model is:

[0080] Where, is micro strain, .

[0081] like Figure 9 As shown, the coefficient of determination R of the fitting function 2 =0.9981, which is very close to 1. Therefore, the strain-deflection transfer function model can better explain the relationship between the strain at the fixed end and the deflection at the free end of the elastic roll.

[0082] like Figure 10 As shown in the figure, after the model is established, several sets of strain-deflection data are collected again to form an independent validation set to evaluate the generalization ability of the strain-deflection transfer function model. R 2 The validation data is very high, but it is very low, indicating that the model is overfitting. In addition, simulation data is added for comparison to ensure the accuracy of simulation modeling and model fitting. R 2 The errors are all less than 5%, indicating that the established strain-deflection transfer function model can well explain the relationship between the fixed end strain and the free end deflection of the elastic roll with special structure.

[0083] In addition, in this embodiment, a set of typical X-axis coordinate-deflection sample sets are obtained as shown in Tables 2 and 3 below: Table 2: X-axis coordinate-deflection sample set-1

[0084] Table 3: X-axis coordinate-deflection sample set-2

[0085] Taking the sample data in Tables 2 and 3 as an example, the measured data points are connected into a smooth curve to obtain the measured deflection curve in this state, as shown in the following figure: Figure 11 shown.

[0086] In summary, the present invention records the strain data at the strain extreme value of the fixed end of the elastic roll, obtains the deflection data of the free end of the elastic roll through the optical measurement component, constructs a strain-deflection transfer model based on the fixed end strain data and the free end deflection data, and can output the deflection curve of the elastic roll under different strains, providing data and theoretical support for the free end deflection inversion analysis, deformation analysis and theoretical derivation of the deflection curve of the special spirally wound stacked structure of the elastic roll of the detection object, and has very good application prospects.

[0087] In addition, the elastic drum deflection inversion calculation method and verification device involved in the present invention have wide applicability. In order to meet the needs of ground tests in special environments such as aging test chambers and thermal vacuum test chambers, as well as the needs of obtaining the deflection of the free end of the elastic drum during on-orbit service, the device can be adaptively improved by selecting high-temperature resistant or low-temperature resistant strain gauges and combining them with necessary temperature compensation means. Specifically, the strain gauge model can be selected according to the temperature range of the test environment, such as using high-temperature resistant strain gauges in high-temperature environments and using low-temperature resistant strain gauges in low-temperature environments. At the same time, in order to eliminate the influence of temperature changes on the measurement results, a temperature sensor and a temperature compensation algorithm can be equipped to monitor the ambient temperature in real time and correct the measurement data. Through the above improvements, the present invention can achieve accurate measurement of the deflection of the elastic drum under special environments, further expanding its scope of application.

[0088] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0089] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0090] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for inverse calculation of elastic drum deflection based on strain analysis, characterized in that: include: Perform strain analysis on the elastic roll to obtain strain data of the fixed end of the elastic roll and deflection data of the free end of the elastic roll; Generate a sample set of strain and deflection data of the elastic roll according to the strain data of the fixed end of the elastic roll and the deflection data of the free end of the elastic roll; According to the strain and deflection data sample set, the polynomial relationship between strain and deflection is obtained, and the polynomial relationship is written into a matrix form to obtain the matrix relationship between strain and deflection; The coefficient vectors of the matrix relationship at different orders are calculated, and the order of the polynomial relationship is determined by combining the Akaike information criterion to obtain the polynomial equations of strain and deflection. Based on the polynomial equation and the obtained strain data, an inverse calculation is performed to obtain the free end deflection of the elastic drum.

2. The method for inverse calculation of elastic drum deflection based on strain analysis according to claim 1, characterized in that: Obtain the strain data of the fixed end of the elastic roll, including: Fix the end of the elastic roll with a larger diameter to the fixture as the fixed end, and the other end as the free end; Return the initial deflection of the free end to zero; The full-bridge strain gauge attached to the extreme strain value is used to collect the strain data under the free end deflection gradient loading to obtain the strain data of the fixed end of the elastic drum. .

3. The method for inverse calculation of elastic drum deflection based on strain analysis according to claim 2, characterized in that: Obtain the deflection data of the free end of the elastic drum, including: The connection between the elastic reel and the fixture is taken as the reference plane, and the deflection when the laser displacement meter faces the reference plane is taken as the deflection zero position reference; Return the initial deflection of the free end to zero; A laser displacement meter is installed just above the elastic drum and can move along the length of the elastic drum to collect the deflection data of the free end under the gradient loading of the deflection, and the deflection data of the free end of the elastic drum is obtained. .

4. The elastic drum deflection inversion calculation method based on strain analysis according to any one of claims 1 to 3, characterized in that: According to the strain and deflection data sample set, the polynomial relationship between strain and deflection is obtained, including: Where, is the deflection data, is the strain data, is the order of the polynomial relation, is the undetermined coefficient.

5. The method for inverse calculation of elastic drum deflection based on strain analysis according to claim 4 is characterized in that: The polynomial relationship is written in matrix form to obtain the matrix relationship between strain and deflection, including: in, Where, is the design matrix, is the observation vector, is the coefficient vector, is the number of sample groups in the strain and deflection data sample set.

6. The method for inverse calculation of elastic drum deflection based on strain analysis according to claim 5, characterized in that: Calculate the coefficient vectors of the matrix relationship at different orders, and combine the Akaike information criterion to determine the order of the polynomial relationship, and obtain the polynomial equations of strain and deflection, including: Compute the coefficient vectors of matrix relations at different orders: Where, for The transpose of Combined with Akaike's information criterion, the order of the polynomial relationship is determined to be the minimum value without the occurrence of singular matrices, and the polynomial equations of strain and deflection are obtained.

7. An elastic drum deflection inversion calculation device based on strain analysis, characterized in that: The method for calculating the deflection of an elastic drum based on strain analysis according to any one of claims 1 to 6 comprises: a base assembly, a gantry assembly, a motion control assembly, a motion guide assembly, an optical measurement assembly, a gravity balance assembly, a strain monitoring assembly, an elastic drum, and an elastic drum fixture; The base assembly is a flat plate structure and serves as a reference platform for the device; The gantry assembly is arranged on the base assembly, including a horizontal beam and two vertical beams, the ends of the horizontal beam are respectively connected to a vertical beam and are arranged parallel to the base assembly, so that the base assembly and the gantry assembly together form a "mouth" shaped frame structure; The motion control assembly is arranged on the horizontal beam and is connected to the motion guide assembly to drive the motion guide assembly; The motion guide assembly is provided on the horizontal beam to drive the optical measurement assembly; The optical measurement assembly is arranged on the motion guide assembly, so that the optical measurement assembly moves along the length direction of the elastic roll under the drive of the motion guide assembly and collects deflection data of the free end of the elastic roll; The gravity balance component is arranged on the base component to realize the zero return of the initial deflection of the free end of the elastic reel and adjust the deflection of the free end of the elastic reel together with the optical measurement component; The strain monitoring component collects strain data of the fixed end of the elastic drum by attaching a strain gauge to the strain extreme value area on the outer circumference of the elastic drum; The elastic reel is used as a detection object, and the end of the elastic reel with a larger diameter is fixed on the elastic reel fixture and serves as a fixed end, while the other end is a free end.

8. The elastic drum deflection inversion calculation device based on strain analysis according to claim 7, characterized in that: The motion guide assembly includes: a bottom plate, a side plate, a partition plate, a linear guide rail, a ball screw, a motion slide and a stepper motor; The bottom plate is arranged on the horizontal beam along the length direction of the horizontal beam; There are two side panels, which are respectively vertically arranged at both ends of the bottom plate; The partition is vertically arranged on the bottom plate and between the two side plates; There are two linear guide rails, which are arranged in parallel and spaced apart on both sides of the ball screw; the linear guide rail and the ball screw are both arranged between the partition and a side plate, one corresponding end is connected to the partition, and the other corresponding end passes through the motion slide and is connected to a side plate; The stepping motor is arranged between the partition plate and the other side plate.

9. The elastic drum deflection inversion calculation device based on strain analysis according to claim 8, characterized in that: The gravity balance assembly includes: a lifting platform, a lifting slider, a balance bracket and an adjusting screw; The lifting platform is vertically arranged on the base assembly at a position corresponding to the midpoint of the elastic reel; The lifting slider is arranged on the lifting platform and has a travel along the length direction of the lifting platform; The balancing bracket is provided on the lifting slider and is linked with the lifting slider to realize the zero return of the initial deflection of the free end of the elastic drum and adjust the deflection of the free end of the elastic drum together with the optical measurement component; The adjusting screw is arranged on the lifting slider to adjust the position of the lifting slider on the lifting platform.

10. The elastic drum deflection inversion calculation device based on strain analysis according to claim 9, characterized in that: The strain monitoring assembly includes: a main strain gauge and an auxiliary strain gauge; The main strain gauge is provided on the lower outer edge of the first spiral turn from the fixed end to the free end of the elastic drum, and the auxiliary strain gauge is provided on the lower outer edge of the second spiral turn from the fixed end to the free end of the elastic drum; The main strain gauge and the auxiliary strain gauge are both connected to an external signal conditioning circuit.

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