Method and device for multi-parameter on-line measurement of stress and strain
By establishing a load-strain response model and a strain gauge sensing array, multi-cycle stress tracking control of the stress-strain measurement device was realized, solving the problem of low control accuracy and efficiency of traditional devices in the coordinated operation of multiple actuators, and realizing dynamic tracking and adaptive control of stress distribution.
Patent Information
- Application Number
- CN202511673792.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-14
- Publication Date
- 2026-03-20
AI Technical Summary
Traditional stress-strain measurement devices struggle to achieve precise and stable control when multiple actuators work together, leading to repeated oscillations and low efficiency under complex coupling relationships, thus failing to achieve the accuracy and efficiency required for high-end structural testing.
A load-strain response model is established, and the strain vector is monitored by a strain gauge sensing array and mapped to a stress vector. The load is optimized to adjust the actuator output, thereby achieving multi-cycle stress tracking control.
It achieves dynamic tracking and adaptive control of stress distribution, accurately feeds back benchmarks and quantified data, eliminates experience-based judgment, automatically coordinates actuator actions, and ensures stable convergence within the system's safety boundaries.
Smart Images
Figure CN121702877A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of stress and strain measurement technology, and more specifically, to a method and apparatus for online measurement of stress and strain using multiple parameters. Background Technology
[0002] Stress-strain measurement devices are core equipment in materials mechanics testing, accurately capturing stress and strain data after materials are subjected to force. This device employs high-precision sensors and data acquisition modules, along with a clamping mechanism to fix the sample, and monitors force and deformation in real time during loading. It features rapid response, a wide measurement range, and strong data stability, supporting various tensile and compressive conditions, and is widely used in the mechanical property evaluation of metals and composite materials.
[0003] Traditional loading control methods rely on pre-defined empirical formulas or simplified load distribution logic, failing to establish a precise and quantitative coupling model between actuator groups and the complex stress field within the structural member. When multiple actuators work collaboratively, there is a strong interactive coupling effect between the load outputs of each actuator. Adjusting the output of any actuator will transmit through the structure and significantly alter the stress state in the affected areas of other actuators. This complex coupling relationship forces operators to use trial-and-error manual adjustments. This process is not only inefficient and heavily reliant on human experience, but also prone to oscillations around the target value due to feedback lag and coupling interference, making convergence difficult. Consequently, it cannot achieve precise and stable control of the complex stress state at a specified section of the member, hindering the accuracy and efficiency of high-end structural testing. Therefore, achieving multi-cycle stress tracking control in load-strain response modeling has become a major challenge for the industry. Summary of the Invention
[0004] This application provides a method and apparatus for online measurement of stress and strain with multiple parameters, which can realize multi-cycle stress tracking control in load-strain response modeling.
[0005] In a first aspect, this application provides a method for multi-parameter online measurement of stress and strain, comprising: Before loading the target component, a load-strain response model is established to characterize the correspondence between the loading force vectors of multiple actuators and the strain vectors measured by the strain gauge sensing array pasted on a specified section of the target component. At the same time, the mapping relationship between the strain vector and the stress vector is obtained. During the loading process of the target component, the strain gauge sensing array is used to monitor the actual strain vector of a specified section of the target component, and then the actual strain vector is converted into the actual stress vector of the stress point of the specified section according to the mapping relationship. A target stress vector is set at a specified cross-section stress point. The actual stress vector is compared with the target stress vector to obtain a stress deviation vector. The primary objective is to minimize the L2 norm of the stress deviation vector. The constraint is that the total load of each actuator does not exceed a set threshold. The load-strain response model is used to optimize the load of each actuator to obtain the load correction amount of each actuator. Each load correction is sent to the controller of the corresponding actuator, and the output force of each actuator is adjusted in a multi-cycle coordinated manner so that the actual stress distribution of the target component at a specified section dynamically tracks the preset target stress distribution.
[0006] In some embodiments, establishing a load-strain response model that characterizes the correspondence between the loading force vectors of multiple actuators and the strain vectors measured by a strain gauge sensing array attached to a specified section of the target component specifically includes: The single-factor loading method was used for experimental calibration. A known unit load was applied to each actuator in turn to obtain the loading force vector characterizing multiple actuators. Record the measured values of each strain gauge in the strain gauge sensing array to form the strain vector of a specified section of the target component; The loading force vector and each unit load are used to construct a mapping matrix between the loading force vector and the strain vector; The load-strain response model establishes the correspondence between the loading force vector and the strain vector through the mapping matrix.
[0007] In some embodiments, converting the actual strain vector into the actual stress vector at a specified cross-section stress point according to the mapping relationship specifically includes: For each stress point in a specified section of the target component, the actual strain value of the stress point is obtained from the actual strain vector; The actual stress value corresponding to the actual strain value is obtained from the mapping relationship, and then the actual stress value of each stress point in the specified section of the target component is obtained; The actual stress vector at the stress point of a specified section is determined by using all actual stress values.
[0008] In some embodiments, comparing the actual stress vector with the target stress vector to obtain the stress deviation vector specifically includes: For each stress point in a specified section of the target component, obtain the actual stress value of the stress point in the actual stress vector, and obtain the target stress value of the stress point in the target stress vector; The stress deviation at the stress point is determined by the component difference between the actual stress value and the target stress value, thereby obtaining the stress deviation at each stress point in the specified section of the target component. The stress deviation vector is determined based on all stress deviations.
[0009] In some embodiments, the load-strain response model is used to optimize the load on each actuator, and the load correction for each actuator is specifically included in the following: For each actuator, obtain the initial load of the actuator; The initial load is mapped using the mapping matrix in the load-strain response model to obtain the load mapping value of the actuator. The load mapping value is iteratively constrained according to the constraints and primary objectives in the load-strain response model to obtain the load correction amount of the actuator, and then the load correction amount of each actuator is obtained.
[0010] In some embodiments, the actuator is an electric cylinder driven by a servo motor.
[0011] In some embodiments, the strain gauge sensing array is a mechanical sensor array of metal resistive strain gauges.
[0012] Secondly, this application provides a multi-parameter online stress-strain measurement device, comprising: The acquisition module is used to establish a load-strain response model before loading the target component, which characterizes the correspondence between the loading force vectors of multiple actuators and the strain vectors measured by the strain gauge sensing array pasted on a specified section of the target component, and at the same time acquire the mapping relationship between the strain vector and the stress vector. The processing module is used to monitor the actual strain vector of a specified section of the target component during the loading process of the target component using the strain gauge sensing array, and then convert the actual strain vector into the actual stress vector of the stress point of the specified section according to the mapping relationship. The processing module is also used to set the target stress vector of the stress point of the specified section, compare the actual stress vector with the target stress vector to obtain the stress deviation vector, take minimizing the L2 norm of the stress deviation vector as the primary objective, take the total load of each actuator not exceeding the set threshold as the constraint condition, use the load-strain response model to optimize the load of each actuator, and obtain the load correction amount of each actuator. The execution module is used to send the various load correction values to the controller of the corresponding actuator, and to perform multi-cycle coordinated adjustment of the output force of each actuator, so that the actual stress distribution of the target component at a specified section dynamically tracks the preset target stress distribution.
[0013] Thirdly, this application provides a computer device, the computer device including a memory and a processor, the memory for storing a computer program, and the processor for calling and running the computer program from the memory, so that the computer device performs the above-described method for online measurement of multi-parameter stress and strain.
[0014] Fourthly, this application provides a computer-readable storage medium storing instructions or code that, when executed on a computer, cause the computer to perform the above-described method for online measurement of stress and strain using multiple parameters.
[0015] The technical solutions provided by the embodiments disclosed in this application have the following beneficial effects: This application provides a method and apparatus for multi-parameter online measurement of stress and strain. Before loading a target component, a load-strain response model is established to characterize the correspondence between the loading force vectors of multiple actuators and the strain vectors measured by a strain gauge sensing array attached to a specified section of the target component. Simultaneously, the mapping relationship between the strain vectors and stress vectors is obtained. During the loading process of the target component, the strain gauge sensing array monitors the actual strain vector at a specified section of the target component. Based on the mapping relationship, the actual strain vector is converted into the actual stress vector at the stress point of the specified section. A target stress vector is set at the stress point of the specified section. The actual stress vector is compared with the target stress vector to obtain a stress deviation vector. Minimizing the L2 norm of the stress deviation vector is the primary objective, and the total load of each actuator does not exceed a set threshold is used as a constraint. The load-strain response model is used to optimize the load of each actuator, obtaining the load correction amount for each actuator. Each load correction amount is sent to the controller of the corresponding actuator, and the output force of each actuator is adjusted in a multi-cycle coordinated manner, so that the actual stress distribution at the specified section of the target component dynamically tracks the preset target stress distribution.
[0016] Therefore, in this application, each load correction is sent to the controller of the corresponding actuator, and the output force of each actuator is adjusted in a multi-cycle coordinated manner, so that the actual stress distribution of the target component at a specified cross section dynamically tracks the preset target stress distribution. First, by determining the actual stress vector, a precise feedback benchmark for stress tracking can be obtained. By converting the physical signals collected by the strain gauge sensing array into the actual stress vector of the specified cross section in real time according to the pre-established strain-stress mapping relationship, the monitored object is transformed from an indirect strain variable related to material properties to a stress force that directly characterizes the stress state of the structure. This yields quantitative data on the current stress state of the structure that is directly comparable to the preset target. The difference between the actual stress vector and the target stress vector constitutes the stress deviation vector. This stress deviation vector accurately quantifies all the differences between the current stress field and the expected stress field in terms of spatial distribution and numerical magnitude, thus eliminating the ambiguity of relying on empirical qualitative judgment. Then, by determining the load correction, a systematic coordinated loading command that satisfies multi-objective constraints can be obtained, thereby transforming the control objective into an executable strategy and dynamically compensating for system deviations. This transforms a complex multivariate coupled control problem into an optimization problem with clear mathematical meaning. By solving this problem, the obtained load correction amount is a systematic collaborative operation command that fully considers the influence of the structural coupling between all actuators. This enables automatic coordination of the actions of each actuator to work together in the most effective way to reduce the global stress deviation, while ensuring that the total output of the entire loading system is within the safety boundary. In the multi-cycle iteration, each correction amount solution is an evaluation and re-optimization of the loading effect of the previous cycle, which can dynamically compensate for the system deviation caused by structural nonlinearity, material creep, or external disturbances. This drives the actual stress distribution to continuously and stably converge to the preset target stress distribution, realizing true intelligent tracking and adaptive control. In summary, based on the above scheme, multi-cycle stress tracking control in load-strain response modeling can be realized. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is an exemplary flowchart of a method for online measurement of stress and strain using multiple parameters, according to some embodiments of this application; Figure 2 This is a flowchart illustrating the process of determining the load correction amount according to some embodiments of this application; Figure 3 This is a schematic diagram of the structure of a multi-parameter online stress-strain measurement device according to some embodiments of this application; Figure 4 This is a schematic diagram of the structure of a computer device for implementing a method for online measurement of stress and strain of multiple parameters, according to some embodiments of this application. Detailed Implementation
[0019] To better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0020] refer to Figure 1 The figure is an exemplary flowchart of a method for online multi-parameter stress-strain measurement according to some embodiments of this application. The method for online multi-parameter stress-strain measurement mainly includes the following steps: In step 101, before loading the target component, a load-strain response model is established to characterize the correspondence between the loading force vectors of multiple actuators and the strain vectors measured by the strain gauge sensing array pasted on a specified section of the target component. At the same time, the mapping relationship between the strain vector and the stress vector is obtained.
[0021] In some embodiments, a load-strain response model characterizing the correspondence between the loading force vectors of multiple actuators and the strain vectors measured by a strain gauge sensing array attached to a specified section of the target component can be established by the following steps: The single-factor loading method was used for experimental calibration. A known unit load was applied to each actuator in turn to obtain the loading force vector characterizing multiple actuators. Record the measured values of each strain gauge in the strain gauge sensing array to form the strain vector of a specified section of the target component; The loading force vector and each unit load are used to construct a mapping matrix between the loading force vector and the strain vector; The load-strain response model establishes the correspondence between the loading force vector and the strain vector through the mapping matrix.
[0022] It should be noted that, in this application, the actuator is an electric cylinder driven by a servo motor; the strain gauge sensing array is a mechanical sensor array of metal resistive strain gauges; the load-strain response model is a mathematical model used to predict the theoretical strain vector to be generated at a specified cross-section of the target component; the unit load is a force value whose magnitude and direction are known, used as a reference input signal; the loading force vector is an ordered array characterizing the combined state of all actuator output forces; the strain vector is an ordered array composed of all strain gauge measurements characterizing the deformation response of a specified cross-section of the target component under a specified load; and the mapping matrix is a coefficient matrix used to establish a linear transformation relationship between the loading force vector and the strain vector.
[0023] In specific implementation, firstly, a single-factor loading method is used for experimental calibration. A known unit load is applied to each actuator sequentially. The loading force vector representing multiple actuators can be obtained as follows: During the experimental calibration phase, each actuator is controlled independently and sequentially, and a pre-set force of known magnitude is applied to each actuator. This force is called the unit load. At the same time, the output force of all other actuators is kept zero. In this way, the complex multi-factor coupled loading is decomposed into a series of simple loading conditions with a single factor. During this process, the set of all actuator output forces corresponding to each single actuator loading is recorded. This set constitutes a loading force vector describing the current loading state. Secondly, the measured values of each strain gauge in the strain gauge sensing array are recorded to form the strain vector of the specified section of the target component. This can be achieved as follows: Under the stable loading state of each single actuator applying a unit load, the real-time measurement readings of each strain gauge in the strain gauge sensing array pasted on the specified section of the target component are synchronously collected and recorded. The readings from all strain gauges measured under the same loading state are then combined. The strain vectors are arranged and combined in a predetermined order to reflect the overall deformation response of the specified cross section under the current load. Then, the loading force vector and each unit load are used to construct a mapping matrix between the loading force vector and the strain vector. This can be achieved by: collecting multiple strain vectors corresponding to the unit load applied by each actuator; arranging each strain vector as a column vector according to the loading order of the actuators to assemble a mathematical matrix; this matrix establishes a linear transformation relationship from the space of the loading force vector to the space of the strain vector, and this matrix is the mapping matrix. Finally, the load-strain response model establishing the correspondence between the loading force vector and the strain vector through the mapping matrix can be achieved by: using the mapping matrix as the relation matrix, constructing a mathematical relation with the loading force vector as input and the calculated strain vector as output; this mathematical relation formally establishes the load-strain response model, which can predict the theoretical strain vector to be generated at a specified cross section of the target component given any loading force vector.
[0024] In some embodiments, the mapping relationship between the strain vector and the stress vector can be obtained by using the mapping matrix in the load-strain response model as the mapping relationship between the strain vector and the stress vector. In other embodiments, to improve the accuracy of the mapping relationship, the constitutive equation can be constructed based on the material properties of the specified section of the target component, namely Young's modulus and Poisson's ratio, and combined with the mechanical state of the section (e.g., plane stress state). This equation mathematically characterizes the intrinsic physical relationship between the stress tensor and the strain tensor. The constitutive equation is expanded from tensor form and reorganized into matrix operation form. This matrix operation clearly defines the linear transformation rules from each component of the strain vector to each component of the stress vector. The coefficients in this linear transformation rule are extracted and organized into a transformation matrix, which formally establishes the mapping relationship from the strain vector to the stress vector. The method of determining this mapping relationship is not limited here.
[0025] In step 102, during the loading process of the target component, the strain gauge sensing array is used to monitor the actual strain vector of a specified section of the target component, and then the actual strain vector is converted into the actual stress vector of the stress point of the specified section according to the mapping relationship.
[0026] In some embodiments, during the loading process of the target component, monitoring the actual strain vector of a specified cross-section of the target component using the strain gauge sensing array can be achieved in the following manner: Throughout the entire duration of the load applied by the actuator on the target component, a multi-channel data acquisition module synchronously triggers and reads the real-time measurement signal of each independent strain gauge in the strain gauge sensing array pasted on the specified cross-section of the target component at a fixed sampling period (default is once per minute); the real-time measurement signals are filtered, amplified, and converted from analog to digital to eliminate noise interference and improve the signal-to-noise ratio, thereby obtaining the physical strain reading of each strain gauge at the current moment; subsequently, according to the predefined numbering order of the strain gauges in the sensing array, the processed strain readings of all strain gauges are arranged and combined in an orderly manner to form a dataset that can completely characterize the instantaneous deformation response of the specified cross-section under the current load state, and this dataset is used as the actual strain vector of the specified cross-section of the target component; wherein, the actual strain vector is a mathematical vector characterizing the true deformation response of all measuring points on the specified cross-section of the target component.
[0027] In some embodiments, converting the actual strain vector into the actual stress vector at a specified cross-section stress point according to the mapping relationship can be achieved by the following steps: For each stress point in a specified section of the target component, the actual strain value of the stress point is obtained from the actual strain vector; The actual stress value corresponding to the actual strain value is obtained from the mapping relationship, and then the actual stress value of each stress point in the specified section of the target component is obtained; The actual stress vector at the stress point of a specified section is determined by using all actual stress values.
[0028] It should be noted that, in this application, the actual stress vector is an ordered array composed of all actual stress values that characterizes the stress state of all stress points at a specified section of the target component; the actual strain value is a quantified value describing the internal force intensity at each stress point in the specified section of the target component; and the actual stress value is data describing the deformation directly obtained by measurement at each stress point in the specified section of the target component.
[0029] In specific implementation, firstly, for each stress point in a specified section of the target component, the actual strain value of the stress point can be obtained from the actual strain vector in the following way: For each stress point in a specified section of the target component, according to the pre-set stress point location information, locate and read the strain measurement data corresponding to the stress point from the actual strain vector; extract the measurement values of one or more strain gauges directly associated with the stress point to form the actual strain value specific to that stress point; then, obtain the actual stress value corresponding to the actual strain value from the mapping relationship, and thus obtain the actual stress value of each stress point in the specified section of the target component. This can be achieved in the following way: by obtaining the actual strain value of the stress point... The variable value is used as input and substituted into the calculation formula specified by the mapping relationship for numerical calculation, thereby solving for the actual stress value at the stress point corresponding to the current strain state. This is the actual stress value corresponding to the actual strain value. In this way, the actual stress value of each stress point in the specified section of the target component can be obtained. Finally, the actual stress vector of the stress point of the specified section can be determined by the following method: the actual stress values of all stress points are collected and arranged according to the same component order and data structure as the target stress vector; the ordered arrangement of the actual stress values representing the stress state of the entire specified section is combined into a mathematical vector, which is the actual stress vector of the stress point of the specified section.
[0030] In step 103, a target stress vector is set at the stress point of a specified section. The actual stress vector is compared with the target stress vector to obtain a stress deviation vector. The primary objective is to minimize the L2 norm of the stress deviation vector. The constraint is that the total load of each actuator does not exceed a set threshold. The load-strain response model is used to optimize the load of each actuator to obtain the load correction amount of each actuator.
[0031] It should be noted that in this application, the target stress vector is a desired reference array composed of the target stress components of all stress points on a specified cross section in a predetermined order. In specific implementation, according to the design specifications, test outline, or service condition requirements of the target component, the ideal stress state that needs to be achieved or tracked at one or more stress points on the specified cross section is determined in advance. For each specified stress point, based on the theory of mechanics of materials and elasticity, the normal stress and shear stress components that need to be controlled are defined. For example, in the plane stress state, two normal stress components and one shear stress component need to be defined. The target stress components of all stress points are arranged in a predefined and uniform order to form a complete and ordered mathematical array, which can be used as the target stress vector of the stress points on the specified cross section.
[0032] In some embodiments, comparing the actual stress vector with the target stress vector to obtain the stress deviation vector can be achieved by the following steps: For each stress point in a specified section of the target component, obtain the actual stress value of the stress point in the actual stress vector, and obtain the target stress value of the stress point in the target stress vector; The stress deviation at the stress point is determined by the component difference between the actual stress value and the target stress value, thereby obtaining the stress deviation at each stress point in the specified section of the target component. The stress deviation vector is determined based on all stress deviations.
[0033] It should be noted that, in this application, the stress deviation vector is an ordered array characterizing the stress control error of all stress points at a specified cross section of the target component; the actual stress value is a data set describing the true stress components at each stress point in the specified cross section of the target component; the target stress value is a data set describing the expected stress components at each stress point in the specified cross section of the target component; and the stress deviation is a data set quantifying the difference between the actual stress value and the target stress value at each stress point.
[0034] In specific implementation, firstly, for each stress point in the specified cross section of the target component, the actual stress value of the stress point in the actual stress vector is obtained, and the target stress value of the stress point in the target stress vector is obtained. This can be achieved in the following way: For each stress point in the specified cross section of the target component, according to the predefined stress point number and order, all actual stress components corresponding to the stress point are located and read from the actual stress vector representing the true stress state of the entire cross section, and the set of all actual stress components is taken as the actual stress value of the stress point; simultaneously, from the target stress vector representing the desired stress state, all target stress components corresponding to the same stress point are read in the same order and according to the same rules, and the set of all target stress components is taken as the target stress value of the stress point; then, the stress deviation at the stress point is determined by the component difference between the actual stress value and the target stress value. The stress deviation at each stress point in the specified section of the target component can be obtained by performing element-wise algebraic subtraction between the actual stress value and the actual stress value on the same stress component. The result of this operation is the difference between the stress point and the desired state on each stress component. The set of all the difference values is taken as the stress deviation at the stress point. The stress deviation at each stress point in the specified section of the target component can be obtained in this way. Finally, the stress deviation vector can be determined based on all the stress deviations by collecting and arranging the stress deviations of all stress points according to the component order and data structure that are completely consistent with the target stress vector and the actual stress vector. The ordered stress deviations representing the stress control error of the entire specified section are combined into a complete mathematical vector, which can be used as the stress deviation vector.
[0035] In some embodiments, the load-strain response model is used to optimize the load on each actuator, obtaining the load correction for each actuator, as referenced. Figure 2 The figure is a schematic flowchart of determining the load correction amount in some embodiments of this application. In this embodiment, the load correction amount can be determined by the following steps: In step 1031, for each actuator, the initial load of the actuator is obtained; In step 1032, the initial load is mapped using the mapping matrix in the load-strain response model to obtain the load mapping value of the actuator; In step 1033, the load mapping value is iteratively constrained according to the constraints and primary objectives in the load-strain response model to obtain the load correction amount of the actuator, and then the load correction amount of each actuator is obtained.
[0036] It should be noted that, in this application, the load correction amount is the adjustment amount of the load of each actuator that makes the predicted strain closest to the target strain under all constraints; the initial load amount is an ordered array of the initial output force values of all actuators in the current control cycle; and the load mapping value is a quantified value used to predict the theoretical strain vector that will be generated at a specified section of the target component under the current initial load amount.
[0037] In specific implementation, firstly, for each actuator, the initial load amount of the actuator can be obtained in the following way: at the beginning of each control cycle, the instantaneous value of the force applied by the actuator at the current moment is read from the data buffer of the control system or directly through sensor feedback; this instantaneous value is used as the initial load amount of the actuator; then, the initial load amount is mapped to the load-strain response model using the mapping matrix in the load-strain response model to obtain the load mapping value of the actuator. This can be achieved in the following way: the initial load amount is input as a mathematical vector into the established load-strain response model; using the mapping matrix in the load-strain response model that represents the linear relationship between load and strain, the initial load amount vector is mapped from the load space to the strain space through matrix multiplication, and a predicted strain response vector is calculated; this predicted strain response vector... The strain response vector serves as the load mapping value of the actuator. Finally, based on the constraints and primary objective in the load-strain response model, the load mapping value is iteratively constrained to obtain the load correction amount of the actuator. The load correction amount of each actuator can be obtained in the following way: using the deviation between the load mapping value and the target strain vector as the optimization objective, and the constraints defined in the claims as hard boundaries, including the upper limit of the total actuator load and the output limit of a single actuator, a constrained optimization problem is constructed. A numerical optimization algorithm (e.g., sequential quadratic programming or interior point method) is used to iteratively search within the solution space of this optimization problem until a solution that satisfies all constraints and optimizes the objective is found. This optimal solution is the load correction amount of the actuator. The load correction amount of each actuator can be obtained through the above method.
[0038] In step 104, each load correction amount is sent to the controller of the corresponding actuator, and the output force of each actuator is adjusted in a multi-cycle coordinated manner so that the actual stress distribution of the specified section of the target component dynamically tracks the preset target stress distribution.
[0039] It should be noted that, in this application, the load correction amount is an incremental value used to instruct each actuator to adjust its current output force; the controller is a hardware control unit used to receive the load correction amount instruction and drive each actuator to perform output force adjustment.
[0040] In practice, each load correction is transmitted accurately to the controller of the corresponding actuator via a fieldbus or industrial Ethernet communication network. After receiving its dedicated load correction command, the controller superimposes the load correction with the current output force in its internal force closed-loop control loop to generate a new force setpoint and drives the actuator's drive unit (e.g., a servo motor or electro-hydraulic servo valve) to execute, thereby achieving precise and synchronous adjustment of the output force. This process is carried out continuously and cyclically with a fixed control cycle. Through this multi-cycle coordinated adjustment strategy, the control error characterized by the stress deviation vector is continuously reduced.
[0041] Furthermore, in another aspect of this application, in some embodiments, this application provides a multi-parameter online stress-strain measurement device, with reference to... Figure 3 The figure is a schematic diagram of the structure of a multi-parameter online stress-strain measurement device according to some embodiments of this application. The multi-parameter online stress-strain measurement device includes: an acquisition module 201, a processing module 202, and an execution module 203, which are described below: The acquisition module 201 in this application is mainly used to establish a load-strain response model before loading the target component, which characterizes the correspondence between the loading force vector of multiple actuators and the strain vector measured by the strain gauge sensing array pasted on a specified section of the target component, and at the same time, acquire the mapping relationship between the strain vector and the stress vector. Processing module 202, in this application, is used to monitor the actual strain vector of a specified section of the target component during the loading process of the target component using the strain gauge sensing array, and then convert the actual strain vector into the actual stress vector of the stress point of the specified section according to the mapping relationship. It should be noted that the processing module 202 is also used to set the target stress vector of the stress point of the specified section, compare the actual stress vector with the target stress vector to obtain the stress deviation vector, take minimizing the L2 norm of the stress deviation vector as the primary objective, take the total load of each actuator not exceeding the set threshold as the constraint condition, and use the load-strain response model to optimize the load of each actuator to obtain the load correction amount of each actuator. The execution module 203 in this application is mainly used to send each load correction amount to the controller of the corresponding actuator, and to perform multi-cycle coordinated adjustment of the output force of each actuator, so that the actual stress distribution of the specified section of the target component dynamically tracks the preset target stress distribution.
[0042] The foregoing has detailed examples of the method and apparatus for multi-parameter online measurement of stress and strain provided in the embodiments of this application. It is understood that, in order to achieve the above functions, the corresponding apparatus includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.
[0043] In some embodiments, this application also provides a computer device, the computer device including a memory and a processor, the memory for storing a computer program, and the processor for calling and running the computer program from the memory, so that the computer device performs the above-described method for online measurement of multi-parameter stress and strain.
[0044] In some embodiments, reference Figure 4 The dashed lines in the figure indicate that the unit or module is optional. This figure is a schematic diagram of the structure of a computer device for implementing a method for online multi-parameter stress-strain measurement according to an embodiment of this application. The method for online multi-parameter stress-strain measurement described in the above embodiments can be achieved through… Figure 4 The computer device shown is used to implement this, and the computer device includes at least one processor 301, a memory 302 and at least one communication unit 305. The computer device may be a terminal device, a server or a chip.
[0045] Processor 301 can be a general-purpose processor or a special-purpose processor. For example, processor 301 can be a central processing unit (CPU), which can be used to control computer devices, execute software programs, and process data from software programs. The computer device may also include a communication unit 305 for inputting (receiving) and outputting (transmitting) signals.
[0046] For example, the computer device may be a chip, and the communication unit 305 may be the input and / or output circuit of the chip, or the communication unit 305 may be the communication interface of the chip, which may be a component of a terminal device, network device or other device.
[0047] For example, the computer device may be a terminal device or a server, and the communication unit 305 may be a transceiver of the terminal device or the server, or the communication unit 305 may be a transceiver circuit of the terminal device or the server.
[0048] The computer device may include one or more memories 302 storing a program 304. The program 304 can be executed by a processor 301 to generate instructions 303, causing the processor 301 to execute the method described in the above method embodiments according to the instructions 303. Optionally, the memory 302 may also store data (such as a target audit model). Optionally, the processor 301 may also read data stored in the memory 302, which may be stored at the same storage address as the program 304, or it may be stored at a different storage address than the program 304.
[0049] The processor 301 and memory 302 can be configured separately or integrated together, for example, integrated on the system on chip (SOC) of the terminal device.
[0050] It should be understood that each step of the above method embodiment can be completed by hardware logic circuits or software instructions in the processor 301. The processor 301 can be a CPU, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, such as discrete gates, transistor logic devices, or discrete hardware components.
[0051] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0052] For example, in some embodiments, this application also provides a computer-readable storage medium storing instructions or code that, when executed on a computer, cause the computer to perform the above-described method for online measurement of stress and strain using multiple parameters.
[0053] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.
[0054] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.
Claims
1. A method for online measurement of stress and strain using multiple parameters, characterized in that, Includes the following steps: Before loading the target component, a load-strain response model is established to characterize the correspondence between the loading force vectors of multiple actuators and the strain vectors measured by the strain gauge sensing array pasted on a specified section of the target component. At the same time, the mapping relationship between the strain vector and the stress vector is obtained. During the loading process of the target component, the strain gauge sensing array is used to monitor the actual strain vector of a specified section of the target component, and then the actual strain vector is converted into the actual stress vector of the stress point of the specified section according to the mapping relationship. A target stress vector is set at a specified cross-section stress point. The actual stress vector is compared with the target stress vector to obtain a stress deviation vector. The primary objective is to minimize the L2 norm of the stress deviation vector. The constraint is that the total load of each actuator does not exceed a set threshold. The load-strain response model is used to optimize the load of each actuator to obtain the load correction amount of each actuator. Each load correction is sent to the controller of the corresponding actuator, and the output force of each actuator is adjusted in a multi-cycle coordinated manner so that the actual stress distribution of the target component at a specified section dynamically tracks the preset target stress distribution.
2. The method as described in claim 1, characterized in that, Establishing a load-strain response model that characterizes the correspondence between the loading force vectors of multiple actuators and the strain vectors measured by a strain gauge sensing array attached to a specified section of the target component specifically includes: The single-factor loading method was used for experimental calibration. A known unit load was applied to each actuator in turn to obtain the loading force vector characterizing multiple actuators. Record the measured values of each strain gauge in the strain gauge sensing array to form the strain vector of a specified section of the target component; The loading force vector and each unit load are used to construct a mapping matrix between the loading force vector and the strain vector; The load-strain response model establishes the correspondence between the loading force vector and the strain vector through the mapping matrix.
3. The method as described in claim 1, characterized in that, Converting the actual strain vector into the actual stress vector at the specified cross-section stress point based on the mapping relationship specifically includes: For each stress point in a specified section of the target component, the actual strain value of the stress point is obtained from the actual strain vector; The actual stress value corresponding to the actual strain value is obtained from the mapping relationship, and then the actual stress value of each stress point in the specified section of the target component is obtained; The actual stress vector at the stress point of a specified section is determined by using all actual stress values.
4. The method as described in claim 1, characterized in that, The stress deviation vector is obtained by comparing the actual stress vector with the target stress vector, specifically including: For each stress point in a specified section of the target component, obtain the actual stress value of the stress point in the actual stress vector, and obtain the target stress value of the stress point in the target stress vector; The stress deviation at the stress point is determined by the component difference between the actual stress value and the target stress value, thereby obtaining the stress deviation at each stress point in the specified section of the target component. The stress deviation vector is determined based on all stress deviations.
5. The method as described in claim 1, characterized in that, The load-strain response model is used to optimize the load on each actuator, and the specific load correction for each actuator includes: For each actuator, obtain the initial load of the actuator; The initial load is mapped using the mapping matrix in the load-strain response model to obtain the load mapping value of the actuator. The load mapping value is iteratively constrained according to the constraints and primary objectives in the load-strain response model to obtain the load correction amount of the actuator, and then the load correction amount of each actuator is obtained.
6. The method as described in claim 1, characterized in that, The actuator is an electric cylinder driven by a servo motor.
7. The method as described in claim 1, characterized in that, The strain gauge sensing array is a mechanical sensor array of metal resistive strain gauges.
8. A multi-parameter online stress-strain measurement device, characterized in that, include: The acquisition module is used to establish a load-strain response model before loading the target component, which characterizes the correspondence between the loading force vectors of multiple actuators and the strain vectors measured by the strain gauge sensing array pasted on a specified section of the target component, and at the same time acquire the mapping relationship between the strain vector and the stress vector. The processing module is used to monitor the actual strain vector of a specified section of the target component during the loading process of the target component using the strain gauge sensing array, and then convert the actual strain vector into the actual stress vector of the stress point of the specified section according to the mapping relationship. The processing module is also used to set the target stress vector of the stress point of the specified section, compare the actual stress vector with the target stress vector to obtain the stress deviation vector, take minimizing the L2 norm of the stress deviation vector as the primary objective, take the total load of each actuator not exceeding the set threshold as the constraint condition, use the load-strain response model to optimize the load of each actuator, and obtain the load correction amount of each actuator. The execution module is used to send the various load correction values to the controller of the corresponding actuator, and to perform multi-cycle coordinated adjustment of the output force of each actuator, so that the actual stress distribution of the target component at a specified section dynamically tracks the preset target stress distribution.
9. A computer device, characterized in that, The computer device includes a memory and a processor, the memory for storing computer programs, and the processor for calling and running the computer programs from the memory, causing the computer device to perform the method for multi-parameter online measurement of stress and strain as described in any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions or code that, when executed on a computer, cause the computer to perform the method for online multi-parameter measurement of stress and strain as described in any one of claims 1 to 7.