Large-tonnage high-frequency-response electro-hydraulic servo resonance fatigue test control system and method

Abstract

The invention discloses a large-tonnage high-frequency-response electro-hydraulic servo resonance fatigue test control system and method, and relates to the technical field of fatigue testing, and the method comprises the steps: generating a first output load through a preset static pressure support actuator; wherein the first output load is an output load of which the frequency meets a preset high-frequency judgment condition; carrying out resonance amplification on the load component of the first output load by utilizing the vibration system and through a preset resonance amplification unit to obtain a second output load; based on the second output load and in combination with a preset double-closed-loop control mechanism, constructing an alternating load loading environment, and performing a fatigue test on the to-be-tested material sample in the alternating load loading environment to obtain a fatigue test result of the to-be-tested material sample; wherein the preset double-closed-loop control mechanism is a mechanism used for performing double-closed-loop control on the alternating displacement and / or the load amplitude. The large-tonnage and high-frequency-response fatigue loading capacity is achieved for the first time, and the test period is greatly shortened while energy consumption is remarkably reduced.

Description

Technical Field

[0001] This application relates to the field of fatigue testing technology, and in particular to a large-tonnage high-frequency electro-hydraulic servo resonant fatigue test control system and method. Background Technology

[0002] Fatigue testing is a core testing component in materials research and equipment manufacturing. With the rapid development of materials science and equipment manufacturing, the dimensions of components in large, heavy equipment such as high-speed trains and ships are constantly increasing, and the properties of materials are continuously being enhanced. During their service life, these components must withstand loads of tens of tons, and their lifespan requirements must reach [a certain threshold]. The extremely high cycle count places higher demands on the load-bearing capacity, operating frequency, and energy efficiency of the fatigue testing system.

[0003] Currently, the mainstream fatigue testing equipment in the industry is mainly divided into two categories: one is the traditional electro-hydraulic servo fatigue testing machine, which, although capable of large-tonnage load output and various stress types, suffers from significant drawbacks such as low loading frequency, long test cycles, and high energy consumption, making it difficult to meet the efficiency requirements of ultra-high cycle fatigue testing; the other is the electromagnetic resonant fatigue testing machine, which, based on the resonance principle, can achieve high-frequency loading and is energy-saving and environmentally friendly, but has limitations such as low stress load and limited loading types, making it unsuitable for the large-tonnage load testing needs of large equipment components. Therefore, how to achieve higher loading frequencies and larger load outputs with lower energy consumption while ensuring the authenticity and accuracy of the test has become a key problem that urgently needs to be solved in the field of fatigue testing technology. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a high-tonnage, high-frequency response electro-hydraulic servo resonant fatigue test control system and method, capable of achieving high-tonnage, high-frequency response, and low-energy-consumption fatigue loading capabilities. The specific solution is as follows:

[0005] In a first aspect, this application provides a high-tonnage high-frequency electro-hydraulic servo resonant fatigue test control method, applied to a preset fatigue load loading system. The preset fatigue load loading system includes a first load loading subsystem, which includes a preset hydrostatic support actuator and a preset multi-degree-of-freedom resonant system. The preset multi-degree-of-freedom resonant system includes a preset resonant amplification unit and a vibration system constructed based on multi-level weights and springs. The method includes:

[0006] A first output load is generated by a preset hydrostatic support actuator; wherein, the first output load is an output load whose frequency meets a preset high-frequency determination condition;

[0007] The load component of the first output load is resonantly amplified using the vibration system and the preset resonant amplification unit to obtain the second output load.

[0008] Based on the second output load and combined with a preset dual closed-loop control mechanism, an alternating load loading environment is constructed, and fatigue testing is performed on the test material sample in the alternating load loading environment to obtain the fatigue test results of the test material sample; wherein, the preset dual closed-loop control mechanism is a mechanism for performing dual closed-loop control on alternating displacement and / or load amplitude.

[0009] Optionally, before generating the first output load through the preset hydrostatic support actuator, the method further includes:

[0010] The system receives the fatigue test parameters set by the user through the human-computer interaction interface of the host computer, and collects the initial signal using sensors placed on the test material sample and related equipment.

[0011] The initial signal is decomposed and conditioned to obtain the target feature signal, and the target feature signal is converted from analog format to digital format to obtain the digital feature signal;

[0012] According to the preset core control architecture, the corresponding control algorithm is invoked to calculate the digital characteristic signal and the fatigue test parameters, and a first target control command is generated based on the calculation result. The corresponding execution unit is controlled based on the first target control command to construct an alternating load loading environment. The preset core control architecture is an embedded dual-core hardware architecture based on a field-programmable gate array and a digital signal processor.

[0013] Optionally, the preset multi-degree-of-freedom resonant system corresponds to multiple natural frequencies, and different natural frequencies correspond to different resonance frequency points.

[0014] Optionally, a first output load is generated by a preset hydrostatic support actuator, and the load component of the first output load is resonantly amplified using the vibration system and the preset resonant amplification unit to obtain a second output load, including:

[0015] Under the control of a preset high-frequency response servo valve, the first output load is generated by the preset hydrostatic support actuator, whose output frequency meets the preset high-frequency determination condition.

[0016] The first output load is input as an excitation force to the preset multi-degree-of-freedom resonant system. The excitation frequency of the first output load is adjusted by the vibration system and the preset resonant amplification unit so that the adjusted excitation frequency meets the preset resonance condition with the maximum resonance frequency point of the preset multi-degree-of-freedom resonant system, thereby amplifying the amplitude of the first output load to obtain the second output load.

[0017] Optionally, the process of performing fatigue testing on the material specimen under test in the alternating load environment includes:

[0018] The actual displacement signal and actual load signal of the test material sample are collected. Based on the actual displacement signal, the actual load signal, and the preset target load amplitude and / or target displacement amplitude, basic control commands are generated through a dual closed-loop control mechanism.

[0019] A dynamic compensation signal is generated based on a preset compensation algorithm; the preset compensation algorithm is used to identify and predict the dynamic error caused by the nonlinear characteristics and time-varying parameters of the hydraulic servo system, and to generate a dynamic compensation signal based on the dynamic error.

[0020] The basic control command and the dynamic compensation signal are fused to obtain the second target control command, which is then used to optimize the control of the material fatigue testing process.

[0021] Optionally, the preset fatigue load loading system further includes a second load loading subsystem, which uses a servo motor as a power source to generate a third output load or a fourth output load; the third output load is a static average load of different load types, and the fourth output load is an output load whose frequency meets a preset low-frequency determination condition; the load types include tension, compression, and bending; wherein, the method further includes:

[0022] According to the testing requirements of the material sample to be tested, the second load loading subsystem is controlled to generate the corresponding third or fourth output load;

[0023] When the third output load is output, a static and dynamic composite load loading environment is constructed based on the third output load, the second output load, and the preset dual closed-loop control mechanism. The fatigue test of the test material sample is then performed in the static and dynamic composite load loading environment to obtain the fatigue test results of the test material sample.

[0024] When the fourth output load is output, a low-frequency load loading environment is constructed based on the fourth output load and the preset dual closed-loop control mechanism, and fatigue testing is performed on the test material sample in the low-frequency load loading environment to obtain the fatigue test results of the test material sample.

[0025] Optionally, the large-tonnage high-frequency electro-hydraulic servo resonant fatigue test control method further includes:

[0026] When the preset termination condition is met, the corresponding actuator is controlled to stop the load loading and reset, and the fatigue test results are output.

[0027] The preset termination conditions include the current test cycle reaching the preset test cycle, or the test material sample reaching the preset mechanical property failure criterion, or any state signal in the state signals collected in the load loading environment exceeding the corresponding preset safe operation threshold; the preset safe operation threshold includes the load over-limit threshold and the displacement over-limit threshold.

[0028] Secondly, this application provides a high-tonnage high-frequency electro-hydraulic servo resonant fatigue test control system, applied to a preset fatigue load loading system. The preset fatigue load loading system includes a first load loading subsystem, which includes a preset hydrostatic support actuator and a preset multi-degree-of-freedom resonant system. The preset multi-degree-of-freedom resonant system includes a preset resonant amplification unit and a vibration system constructed based on multi-level weights and springs. The high-tonnage high-frequency electro-hydraulic servo resonant fatigue test control system includes:

[0029] The first load generation module is used to generate a first output load through a preset hydrostatic support actuator; wherein, the first output load is an output load whose frequency meets a preset high frequency determination condition.

[0030] The second load generation module is used to resonate and amplify the load component of the first output load using the vibration system and the preset resonant amplification unit to obtain the second output load.

[0031] The fatigue testing module is used to construct an alternating load loading environment based on the second output load and in combination with a preset dual closed-loop control mechanism, and to perform fatigue testing on the test material sample in the alternating load loading environment to obtain the fatigue test results of the test material sample; wherein, the preset dual closed-loop control mechanism is a mechanism for performing dual closed-loop control on alternating displacement and / or load amplitude.

[0032] Optionally, the first load generation module further includes:

[0033] The data acquisition unit is used to receive the fatigue test parameters set by the user through the human-computer interaction interface of the host computer, and to collect the initial signal using sensors arranged on the test material sample and related equipment.

[0034] The format conversion unit is used to decompose and condition the initial signal to obtain the target feature signal, and convert the target feature signal from analog format to digital format to obtain the digital feature signal;

[0035] The environment construction unit is used to call the corresponding control algorithm according to the preset core control architecture to calculate the digital characteristic signal and the fatigue test parameters, and generate a first target control instruction based on the calculation result, so as to control the corresponding execution unit to construct the alternating load loading environment based on the first target control instruction; the preset core control architecture is an embedded dual-core hardware architecture based on a field programmable gate array and a digital signal processor.

[0036] Optionally, the preset multi-degree-of-freedom resonant system corresponds to multiple natural frequencies, and different natural frequencies correspond to different resonance frequency points.

[0037] In this application, a first output load is generated by a preset hydrostatic support actuator; wherein, the first output load is an output load whose frequency meets a preset high-frequency determination condition; the load component of the first output load is resonantly amplified by the vibration system and the preset resonant amplification unit to obtain a second output load; based on the second output load and combined with a preset dual closed-loop control mechanism, an alternating load loading environment is constructed, and fatigue testing is performed on the test material sample in the alternating load loading environment to obtain the fatigue test results of the test material sample; wherein, the preset dual closed-loop control mechanism is a mechanism for dual closed-loop control of alternating displacement and / or load amplitude. As can be seen from the above, on the one hand, this application first utilizes a preset hydrostatic support actuator to generate a high-frequency small load, and then uses a vibration system and a preset resonant amplification unit to amplify the high-frequency small load into a high-frequency large load, thereby achieving a large-tonnage output and resolving the inherent contradiction between large tonnage and high frequency. On the other hand, a preset dual closed-loop control mechanism monitors and dynamically adjusts the output in real time, ensuring that regardless of system disturbances, the frequency, amplitude, and mean of the load waveform applied to the test material sample strictly conform to the test settings, guaranteeing the authenticity and accuracy of the test. Simultaneously, the hydrostatic support actuator only needs to generate a high-frequency small load, which significantly reduces the instantaneous power and hydraulic system size required compared to directly generating a large-tonnage high-frequency load, thus lowering energy consumption. Secondly, the core amplification stage relies on the physical phenomenon of resonance, that is, a large-amplitude vibration load can be maintained with a very small periodic excitation force near the system's natural frequency. This method makes the continuous energy input required to maintain a large-tonnage high-frequency load extremely low, achieving the effect of higher loading frequency and larger load output with lower energy consumption. Attached Figure Description

[0038] 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 embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0039] Figure 1 This application discloses a flowchart of a high-tonnage high-frequency electro-hydraulic servo resonant fatigue test control method.

[0040] Figure 2 This is a schematic diagram of a hierarchical structure disclosed in this application;

[0041] Figure 3 This is a schematic diagram of a frequency-high load curve relationship disclosed in this application;

[0042] Figure 4 This is a schematic diagram of a frequency-magnification curve relationship disclosed in this application;

[0043] Figure 5 (a) is a schematic diagram of a high-frequency response small load excitation force applied by an electro-hydraulic servo according to this application;

[0044] Figure 5 (b) is a schematic diagram of a high-frequency response large load test force resonantly applied to a specimen as disclosed in this application;

[0045] Figure 6 This is a schematic diagram of the peak-valley curve of an alternating load disclosed in this application;

[0046] Figure 7 This is a schematic diagram of a high load peak-valley curve disclosed in this application;

[0047] Figure 8 This is a schematic diagram of the deviation value curve of a dual encoder disclosed in this application;

[0048] Figure 9 This is a schematic diagram of the structure of a large-tonnage high-frequency electro-hydraulic servo resonant fatigue test control system disclosed in this application;

[0049] Figure 10 This is a schematic diagram of the structure of an electronic device disclosed in this application. Detailed Implementation

[0050] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0051] Currently, the mainstream fatigue testing equipment in the industry is mainly divided into traditional electro-hydraulic servo fatigue testing machines and electromagnetic resonant fatigue testing machines. Traditional electro-hydraulic servo fatigue testing machines have significant drawbacks such as low loading frequency, long test cycles, and high energy consumption, making it difficult to meet the efficiency requirements of ultra-high cycle fatigue testing. Electromagnetic resonant fatigue testing machines have limitations such as low stress load and single loading type, making them unsuitable for testing the large tonnage loads of large equipment components. To address this, this application provides a control method for high-tonnage, high-frequency response electro-hydraulic servo resonant fatigue testing, achieving high-tonnage, high-frequency response fatigue loading capabilities. This method significantly reduces energy consumption while greatly shortening the test cycle, overcoming the technical challenge of traditional equipment being unable to simultaneously handle high loads and high frequencies.

[0052] See Figure 1 As shown in the figure, this application discloses a high-tonnage high-frequency electro-hydraulic servo resonant fatigue test control method, applied to a preset fatigue load loading system. The preset fatigue load loading system includes a first load loading subsystem, which includes a preset hydrostatic support actuator and a preset multi-degree-of-freedom resonant system. The preset multi-degree-of-freedom resonant system includes a preset resonant amplification unit and a vibration system based on multi-level weights and springs. The method includes:

[0053] Step S11: Generate a first output load through a preset hydrostatic support actuator; wherein, the first output load is an output load whose frequency meets the preset high frequency determination condition.

[0054] This embodiment mainly includes an application layer, a control layer, and a hardware layer. The application layer, as the system's command and monitoring center, receives user commands through a human-machine interface and sends them to the control layer; simultaneously, it receives information from the control layer and presents the test process and results data in real time. The control layer, as the core processing unit bridging the upper and lower layers, processes and optimizes the commands sent from the application layer using algorithms, converting them into control commands to drive the hardware layer's actuators; it processes physical signals fed back from the hardware layer in real time and generates new control commands to send back to the hardware layer to adjust the actuators; simultaneously, it sends physical signals fed back from the hardware layer to the application layer to update the application layer's display content. The hardware layer, as the execution and feedback unit, receives control commands from the control layer and converts them into physical loading actions; simultaneously, the hardware layer collects physical signals such as load and displacement in real time and feeds them back to the control layer.

[0055] For example Figure 2 The hierarchical structure diagram shown below:

[0056] The hardware layer consists of embedded hardware circuits, mainly including a signal conditioning module, an A / D conversion module, a core control module, a D / A output module, and an execution module, among which:

[0057] Signal conditioning module: decomposes and conditions the raw signals received from the load sensor, LVDT displacement sensor and encoder, and outputs multiple characteristic signals including but not limited to real-time values ​​of alternating load, real-time values ​​of static load, peak values ​​of large load, valley values ​​of large load, peak values ​​of small load, valley values ​​of small load, displacement and encoder values.

[0058] A / D conversion module: converts the analog signals collected from various sensors into digital signals;

[0059] The core control module adopts an embedded dual-core hardware architecture based on FPGA (Field Programmable Gate Array) and DSP (Digital Signal Processor) to process the acquired digital signals, receive control instructions and IO commands issued by the host computer, and execute the corresponding control algorithms.

[0060] D / A output module: Converts the digital control commands output by the core control module into analog signals to drive the actuator;

[0061] The execution module receives control commands and, through a coordinated electro-hydraulic resonant and motor-driven loading mechanism, precisely constructs a load loading environment that meets the test requirements, enabling fatigue testing of the material sample under test within this constructed load loading environment. The execution module includes a first load loading subsystem and a second load loading subsystem. The first load loading subsystem receives control commands via an electro-hydraulic servo valve, precisely adjusting the flow and pressure of the hydraulic oil to drive a hydraulic actuator, such as a hydrostatic support actuator, to generate a first output load. Then, using a vibration system and a preset resonant amplification unit, the load component of the first output load is resonantly amplified to obtain a second output load. The second load loading subsystem uses a servo motor as a power source to generate a third or fourth output load. The third output load is a static average load of different load types, and the fourth output load is an output load of different load types with frequencies meeting preset low-frequency judgment conditions. Load types include tension, compression, and bending. Two servo motors can be used to form a dual-servo synchronous loading system to achieve the application of highly coaxial static average loads or low-frequency loads.

[0062] The control layer is the algorithm processing layer, mainly including electro-hydraulic servo control, high-frequency response loading, servo synchronous loading, PID (Proportional-Integral-Derivative) algorithm, and compensation algorithm, among which:

[0063] Electro-hydraulic servo control: The command signal output by the control system is amplified and input into the high-frequency electro-hydraulic servo valve. The servo valve converts the electrical signal into a valve core displacement signal, and then into hydraulic signals such as flow and pressure, which ultimately drive the hydrostatic support actuator to achieve precise loading control of various waveforms such as sine wave, triangle wave, and square wave.

[0064] High-frequency response loading: Achieve high-frequency alternating load loading control in the range of 1~500Hz to meet preset high-frequency judgment conditions;

[0065] Servo synchronous loading: Through a dual closed-loop control mechanism, the load force and displacement of the two motors in the second load loading subsystem powered by servo motors are synchronously and precisely controlled to generate the load required for low-cycle fatigue testing.

[0066] PID algorithm: A control algorithm that integrates proportional, integral, and derivative functions to improve the control accuracy and robustness of hydraulic servo systems, thereby overcoming the influence of time-varying and nonlinear characteristics of system parameters.

[0067] Compensation Algorithm: Since the flow rate of the hydraulic servo system is affected by many factors such as hydraulic valves, mechanical structure, and oil source system pressure, the oil flow rate may undergo nonlinear changes to varying degrees, resulting in problems such as frequency distortion and amplitude abrupt changes. This affects the reliability of test data and the stability of the equipment during long-term operation. Under the positive intervention of the compensation algorithm, the dynamic behavior and output of the system are monitored in real time, enabling the system to automatically adjust its working parameters according to the real-time feedback signal, maintain the optimal performance of the whole machine, and ensure that the test set frequency, load and other parameter values ​​do not drift or change abruptly.

[0068] The application layer provides users with a host computer operation interface, mainly including an experiment setting unit, a curve status display unit, a running status display unit, an experiment data processing unit, and a performance testing unit, among which:

[0069] Test setup unit: As the core input part of the human-machine interface, it is used to set various parameters before the test begins. Users can select the control mode, such as electro-hydraulic servo control or servo motor control, and input fatigue test parameters including but not limited to loading frequency, load amplitude, average load, and test cycle number. At the same time, users can set the data storage mode, such as by time, cycle, or number of points.

[0070] Curve status display unit: Real-time graphical display of control command curves, as well as feedback curves such as mean load curves and alternating load curves, including the dynamic changes of key parameters such as large load and small load, providing intuitive basis for monitoring and testing process;

[0071] Operation status display unit: Displays key test status information in real time in digital form, including peak and valley values ​​of large / small loads, peak and valley values ​​of displacement, encoder values, test cycle number, and limit alarms, etc., to achieve continuous monitoring of status signals in the load loading environment;

[0072] Experimental Data Processing Unit: Responsible for the storage, management, and subsequent analysis and processing of all data during and after the experiment;

[0073] Performance Testing Unit: As the core selection module for system function execution, it provides a variety of preset test modes. Users can select the appropriate test mode according to the testing requirements of the material sample under test, thereby triggering the system to construct the corresponding load loading environment.

[0074] In this embodiment, before generating the first output load through the preset hydrostatic support actuator, the process may further include: firstly, receiving user-defined fatigue test parameters through the human-machine interface of the host computer, and collecting initial signals using sensors arranged on the test material sample and related equipment. Then, the initial signals are decomposed and conditioned to obtain target characteristic signals, and the target characteristic signals are converted from analog to digital format to obtain digital characteristic signals. Finally, according to the preset core control architecture, the corresponding control algorithm is called to calculate the digital characteristic signals and fatigue test parameters, and a first target control command is generated based on the calculation results. This first target control command is then used to control the corresponding execution components to construct an alternating load loading environment. The preset core control architecture is an embedded dual-core hardware architecture based on a field-programmable gate array (FPGA) and a digital signal processor (DSP).

[0075] Furthermore, under the control of a preset high-frequency response servo valve, a first output load can be generated by using a preset hydrostatic support actuator whose output frequency meets the preset high-frequency judgment condition.

[0076] Step S12: Using the vibration system and the preset resonant amplification unit, the load component of the first output load is resonantly amplified to obtain the second output load.

[0077] In this embodiment, the preset multi-degree-of-freedom resonant system corresponds to multiple natural frequencies, each corresponding to a different resonance frequency point. Accordingly, the load component of the first output load is resonantly amplified using a vibration system and a preset resonant amplification unit to obtain a second output load. This can include: inputting the first output load as an excitation force into the preset multi-degree-of-freedom resonant system; adjusting the excitation frequency of the first output load using the vibration system and the preset resonant amplification unit so that the adjusted excitation frequency satisfies a preset resonance condition with the maximum resonance frequency point of the preset multi-degree-of-freedom resonant system; thereby amplifying the amplitude of the first output load to obtain the second output load.

[0078] Understandably, the hydrostatic support actuator uses hydrostatic support technology, which can achieve high-frequency response and small load output as an excitation unit. In conjunction with the vibration system and resonant amplification unit, it can amplify small loads into large loads while keeping the high frequency unchanged, thereby achieving high-frequency response and large load output.

[0079] Step S13: Based on the second output load and combined with the preset dual closed-loop control mechanism, an alternating load loading environment is constructed, and fatigue testing is performed on the test material sample in the alternating load loading environment to obtain the fatigue test results of the test material sample; wherein, the preset dual closed-loop control mechanism is a mechanism for performing dual closed-loop control on alternating displacement and / or load amplitude.

[0080] In this embodiment, the process of performing fatigue testing on the material sample under alternating load loading environment may include: firstly, acquiring the actual displacement signal and actual load signal of the material sample; based on the actual displacement signal, actual load signal, and preset target load amplitude and / or target displacement amplitude, generating basic control commands through a dual closed-loop control mechanism; then, generating dynamic compensation signals based on a preset compensation algorithm; wherein, the preset compensation algorithm is used to identify and predict dynamic errors caused by the nonlinear characteristics and time-varying parameters of the hydraulic servo system, and generating dynamic compensation signals based on the dynamic errors; finally, fusing the basic control commands and dynamic compensation signals to obtain a second target control command, which is used to optimize the control of the material fatigue testing process.

[0081] When the preset termination conditions are met, the corresponding actuators can be controlled to stop the load loading and reset. At this time, the fatigue test ends and the fatigue test results are output. The preset termination conditions include, but are not limited to, the current test cycle reaching the preset test cycle, or the test material sample reaching the preset mechanical property failure criterion, or any state signal in the state signals collected in the load loading environment exceeding the corresponding preset safe operation threshold. The preset safe operation thresholds include, but are not limited to, the load over-limit threshold and the displacement over-limit threshold.

[0082] It should be noted that if the second load loading subsystem is used in this embodiment, the second load loading subsystem can be controlled to generate a corresponding third or fourth output load according to the testing requirements of the material sample to be tested.

[0083] When the third output load is output, a static and dynamic composite load loading environment is constructed based on the third output load, the second output load, and a preset dual closed-loop control mechanism. Fatigue tests are then performed on the test material sample in the static and dynamic composite load loading environment to obtain the fatigue test results of the test material sample.

[0084] When the fourth output load is output, a low-frequency load loading environment is constructed based on the fourth output load and the preset dual closed-loop control mechanism. Fatigue tests are then performed on the test material sample in the low-frequency load loading environment to obtain the fatigue test results of the test material sample.

[0085] The following is based on Figure 3 The frequency-high load curve relationship diagram shown is as follows: Figure 4 The technical solution in this embodiment will be explained using the frequency-amplification curve diagram shown as an example.

[0086] Figure 3 The vertical axis represents the real-time value under heavy load, and the horizontal axis represents the frequency. Figure 4 The vertical axis represents the magnification factor, and the horizontal axis represents the frequency.

[0087] Figure 3 The diagram visually demonstrates the core resonant characteristics of the system: as the input frequency increases, the large load applied to the sample, i.e., the load amplified by resonance, does not increase linearly, but rather rises sharply to a peak value at a specific frequency of the system, forming a sharp peak. Once the excitation frequency exceeds this point, the large load drops rapidly. This proves that the system has a unique and optimal maximum resonant frequency point, and the maximum output load can be obtained by operating near this point.

[0088] Figure 4 Yes Figure 3 Quantitative interpretation of the phenomenon: This demonstrates the relationship between amplification factor and frequency. Near the maximum resonant frequency, the real-time value of the large load exhibits explosive growth, and the amplification factor rises rapidly in tandem, achieving load amplification of tens or even hundreds of times, resulting in large-tonnage test forces. The peak points of the two graphs correspond perfectly, jointly verifying the effectiveness and efficiency of the "high-frequency electro-hydraulic servo excitation-multi-degree-of-freedom resonant amplification" technology. This demonstrates that with a high-frequency, small-tonnage input, through precise frequency matching, a high-frequency, large-tonnage output can be generated.

[0089] The following is based on Figure 5 The diagram showing the comparison curves of excitation force and test force is as follows: Figure 6 Taking the alternating load peak-valley curve shown as an example, the technical solution in this embodiment will be explained.

[0090] Figure 5In (a), the red curve represents the command value issued by the controller, which guides the hydrostatic support actuator to output the corresponding excitation force according to the command value, i.e., the high-frequency response, low-load excitation force. The green curve represents the actual excitation force output by the hydrostatic support actuator, which is collected in real time by the hardware layer. It reflects the actual execution effect of the excitation link. The red curve and the green curve form a contrast, intuitively showing the deviation between the target and the actual value. During the experiment, the system status can be judged by the deviation between the two curves. If there is a significant deviation, the working parameters can be adjusted in real time by the control layer compensation algorithm, or the application layer limit protection can be triggered to ensure the safety of the experiment and the reliability of the data. In addition, the compensation algorithm has another function: when the host computer presets the compensation value target as a large load, it can increase the green curve according to the control layer compensation algorithm, without being constrained by the real-time compensation of the green curve.

[0091] Figure 5 (a) represents the high-frequency response and small-load excitation force output by the hydrostatic support actuator. Figure 5 (b) represents the high-frequency response and large-load test force that is amplified by the multi-degree-of-freedom resonant system and finally applied to the test sample. Figure 5 (a) and Figure 5 (b) The two curves have the same oscillation period, indicating that after resonant amplification, the load frequency does not shift and always maintains the high-frequency characteristics consistent with the initial excitation force, thus solving the problem of frequency distortion easily caused by traditional amplification mechanisms; at the same time, Figure 5 The absolute values ​​of the peak / trough values ​​of the curve in (b) are Figure 5 The curve in (a) is dozens of times larger, which confirms the effectiveness of the synergistic effect between the hydrostatic support actuator and the multi-degree-of-freedom resonant system, and achieves the design goal of high-frequency response without loss and small load with variable tonnage.

[0092] Figure 6 To verify the stability and accuracy of the system loading, the data processing module was used to curve the load peak and valley data. It can be concluded that the fluctuation of the alternating load peak and valley data under test conditions is small, the symmetry is good, and the maximum stable load peak can reach 580kN, which meets the requirements of large tonnage tests.

[0093] The following is based on Figure 7 The schematic diagram of the peak and valley value curves of the large load shown is as follows: Figure 8 The technical solution in this embodiment will be explained using the schematic diagram of the dual encoder deviation value curve shown as an example.

[0094] Figure 7 and Figure 8 This document presents the peak-to-valley load curves and dual encoder deviation curves for low-cycle fatigue testing under dual servo synchronous control with an amplitude of 200 kN and a frequency of 0.1 Hz, at a test cycle count of 1720. Figure 7 and Figure 8It can be seen that the peak-valley curve has almost no abnormal fluctuations, the control accuracy is high, the dual encoder deviation has almost no change, and no other problems have occurred as the test time gradually increases. The low-cycle fatigue and dual servo synchronous control performance are relatively good.

[0095] As can be seen from the above, this embodiment uses a high-frequency static pressure support actuator to output a small-tonnage excitation force. After physical amplification by the resonant unit, it can output a large load of hundreds of tons while maintaining a high frequency of several hundred hertz. This significantly improves test efficiency, greatly reduces energy consumption, and solves the inherent contradiction that traditional equipment cannot handle both large tonnage and high frequency. In addition, by integrating a static servo loading subsystem and a dual closed-loop precision control algorithm, the system has multi-functional testing capabilities such as tensile, compression, bending, and static-dynamic composite loading. It supports fatigue testing across the entire range from low frequency to high frequency, ensuring accurate and reliable data while providing a powerful testing method for life assessment and reliability design of large components under high-complexity load environments.

[0096] See Figure 9 As shown in the embodiments, this application also discloses a large-tonnage high-frequency electro-hydraulic servo resonant fatigue test control system, applied to a preset fatigue load loading system. The preset fatigue load loading system includes a first load loading subsystem, which includes a preset hydrostatic support actuator and a preset multi-degree-of-freedom resonant system. The preset multi-degree-of-freedom resonant system includes a preset resonant amplification unit and a vibration system constructed based on multi-level weights and springs. The large-tonnage high-frequency electro-hydraulic servo resonant fatigue test control system includes:

[0097] The first load generation module 11 is used to generate a first output load through a preset hydrostatic support actuator; wherein, the first output load is an output load whose frequency meets a preset high frequency determination condition.

[0098] The second load generation module 12 is used to resonate and amplify the load component of the first output load using the vibration system and the preset resonant amplification unit to obtain the second output load.

[0099] The fatigue testing module 13 is used to construct an alternating load loading environment based on the second output load and in combination with a preset dual closed-loop control mechanism, and to perform fatigue testing on the test material sample in the alternating load loading environment to obtain the fatigue test results of the test material sample; wherein, the preset dual closed-loop control mechanism is a mechanism for performing dual closed-loop control on alternating displacement and / or load amplitude.

[0100] In some specific embodiments, the first load generation module 11 further includes:

[0101] The data acquisition unit is used to receive the fatigue test parameters set by the user through the human-computer interaction interface of the host computer, and to collect the initial signal using sensors arranged on the test material sample and related equipment.

[0102] The format conversion unit is used to decompose and condition the initial signal to obtain the target feature signal, and convert the target feature signal from analog format to digital format to obtain the digital feature signal;

[0103] The environment construction unit is used to call the corresponding control algorithm according to the preset core control architecture to calculate the digital characteristic signal and the fatigue test parameters, and generate a first target control instruction based on the calculation result, so as to control the corresponding execution unit to construct the alternating load loading environment based on the first target control instruction; the preset core control architecture is an embedded dual-core hardware architecture based on a field programmable gate array and a digital signal processor.

[0104] In some specific implementations, the preset multi-degree-of-freedom resonant system corresponds to multiple natural frequencies, and different natural frequencies correspond to different resonance frequency points.

[0105] In some specific embodiments, the first load generation module 11 includes:

[0106] The first load generation unit is used to generate a first output load by means of the preset hydrostatic support actuator, under the control of the preset high-frequency response servo valve, which outputs a frequency that meets the preset high-frequency determination condition.

[0107] In some specific embodiments, the second load generation module 12 includes:

[0108] The second load generation unit is used to input the first output load as an excitation force into the preset multi-degree-of-freedom resonant system, and adjust the excitation frequency of the first output load through the vibration system and the preset resonant amplification unit so that the adjusted excitation frequency satisfies the preset resonance condition with the maximum resonance frequency point of the preset multi-degree-of-freedom resonant system, so as to amplify the amplitude of the first output load and obtain the second output load.

[0109] In some specific embodiments, the fatigue testing module 13 includes:

[0110] The first instruction generation unit is used to collect the actual displacement signal and actual load signal of the test material sample, and generate basic control instructions based on the actual displacement signal, the actual load signal, and the preset target load amplitude and / or target displacement amplitude through a dual closed-loop control mechanism.

[0111] A signal generation unit is used to generate a dynamic compensation signal based on a preset compensation algorithm; the preset compensation algorithm is used to identify and predict the dynamic error caused by the nonlinear characteristics and time-varying parameters of the hydraulic servo system, and generate a dynamic compensation signal based on the dynamic error.

[0112] The second instruction generation unit is used to fuse the basic control instruction and the dynamic compensation signal to obtain a second target control instruction, so as to optimize the control of the material fatigue test process using the second target control instruction.

[0113] In some specific embodiments, the preset fatigue load loading system further includes a second load loading subsystem, which uses a servo motor as a power source to generate a third output load or a fourth output load; the third output load is a static average load of different load types, and the fourth output load is an output load whose frequency meets preset low-frequency judgment conditions; the load types include tension, compression, and bending; wherein, the large-tonnage high-frequency electro-hydraulic servo resonant fatigue test control system further includes:

[0114] The third load generation unit is used to control the second load loading subsystem to generate a corresponding third output load or fourth output load according to the test requirements of the test material sample.

[0115] The first fatigue testing unit is used to construct a static and dynamic composite load loading environment based on the third output load, the second output load and the preset dual closed-loop control mechanism when the third output load is output, and to perform fatigue testing on the test material sample in the static and dynamic composite load loading environment to obtain the fatigue test results of the test material sample.

[0116] The second fatigue testing unit is used to construct a low-frequency load loading environment based on the fourth output load and the preset dual closed-loop control mechanism when the fourth output load is output, and to perform fatigue testing on the test material sample in the low-frequency load loading environment to obtain the fatigue test results of the test material sample.

[0117] In some specific embodiments, the large-tonnage high-frequency electro-hydraulic servo resonant fatigue test control system further includes:

[0118] The test termination unit is used to control the corresponding actuators to stop loading the load and reset when the preset termination conditions are met, and to output the fatigue test results.

[0119] The preset termination conditions include the current test cycle reaching the preset test cycle, or the test material sample reaching the preset mechanical property failure criterion, or any state signal in the state signals collected in the load loading environment exceeding the corresponding preset safe operation threshold; the preset safe operation threshold includes the load over-limit threshold and the displacement over-limit threshold.

[0120] Furthermore, embodiments of this application also disclose an electronic device, Figure 10 This is a structural diagram of an electronic device 20 according to an exemplary embodiment. The content of the diagram should not be construed as limiting the scope of this application.

[0121] Figure 10 This is a schematic diagram of the structure of an electronic device 20 provided in an embodiment of this application. Specifically, the electronic device 20 may include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 stores a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the large-tonnage high-frequency response electro-hydraulic servo resonant fatigue test control method disclosed in any of the foregoing embodiments. Alternatively, the electronic device 20 in this embodiment may specifically be an electronic computer.

[0122] In this embodiment, the power supply 23 is used to provide operating voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and external devices, and the communication protocol it follows can be any communication protocol applicable to the technical solution of this application, and is not specifically limited here; the input / output interface 25 is used to acquire external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs, and is not specifically limited here.

[0123] In addition, the memory 22, as a carrier for resource storage, can be a read-only memory, random access memory, disk or optical disk, etc. The resources stored thereon can include operating system 221, computer program 222, etc., and the storage method can be temporary storage or permanent storage.

[0124] The operating system 221 is used to manage and control the various hardware devices on the electronic device 20 and the computer program 222, which may be Windows Server, Netware, Unix, Linux, etc. In addition to including a computer program capable of performing the large-tonnage high-frequency response electro-hydraulic servo resonant fatigue test control method executed by the electronic device 20 as disclosed in any of the foregoing embodiments, the computer program 222 may further include computer programs capable of performing other specific tasks.

[0125] Furthermore, this application also discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, it implements the aforementioned control method for high-tonnage high-frequency electro-hydraulic servo resonant fatigue testing. Specific steps of this method can be found in the corresponding content disclosed in the foregoing embodiments, and will not be repeated here.

[0126] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0127] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software 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.

[0128] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0129] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0130] The technical solutions provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for controlling fatigue testing of high-tonnage high-frequency electro-hydraulic servo resonance systems, characterized in that, The method is applied to a preset fatigue load loading system, which includes a first load loading subsystem, comprising a preset hydrostatic support actuator and a preset multi-degree-of-freedom resonant system. The preset multi-degree-of-freedom resonant system includes a preset resonant amplification unit and a vibration system constructed based on multi-level weights and springs. A first output load is generated by a preset hydrostatic support actuator; wherein, the first output load is an output load whose frequency meets a preset high-frequency determination condition; The load component of the first output load is resonantly amplified using the vibration system and the preset resonant amplification unit to obtain the second output load. Based on the second output load and combined with a preset dual closed-loop control mechanism, an alternating load loading environment is constructed, and fatigue testing is performed on the test material sample in the alternating load loading environment to obtain the fatigue test results of the test material sample; wherein, the preset dual closed-loop control mechanism is a mechanism for performing dual closed-loop control on alternating displacement and / or load amplitude.

2. The method for controlling high-tonnage high-frequency electro-hydraulic servo resonant fatigue tests according to claim 1, characterized in that, Before generating the first output load through the preset hydrostatic support actuator, the process further includes: The system receives the fatigue test parameters set by the user through the human-computer interaction interface of the host computer, and collects the initial signal using sensors placed on the test material sample and related equipment. The initial signal is decomposed and conditioned to obtain the target feature signal, and the target feature signal is converted from analog format to digital format to obtain the digital feature signal; According to the preset core control architecture, the corresponding control algorithm is invoked to calculate the digital characteristic signal and the fatigue test parameters, and a first target control command is generated based on the calculation result. The corresponding execution unit is controlled based on the first target control command to construct an alternating load loading environment. The preset core control architecture is an embedded dual-core hardware architecture based on a field-programmable gate array and a digital signal processor.

3. The method for controlling fatigue testing of large-tonnage high-frequency electro-hydraulic servo resonance according to claim 1, characterized in that, The preset multi-degree-of-freedom resonant system corresponds to multiple natural frequencies, and different natural frequencies correspond to different resonance frequency points.

4. The method for controlling fatigue testing of large-tonnage high-frequency electro-hydraulic servo resonance according to claim 3, characterized in that, A first output load is generated by a preset hydrostatic support actuator. The load component of the first output load is then amplified resonantly using the vibration system and the preset resonant amplification unit to obtain a second output load, including: Under the control of a preset high-frequency response servo valve, the first output load is generated by the preset hydrostatic support actuator, whose output frequency meets the preset high-frequency determination condition. The first output load is input as an excitation force to the preset multi-degree-of-freedom resonant system. The excitation frequency of the first output load is adjusted by the vibration system and the preset resonant amplification unit so that the adjusted excitation frequency meets the preset resonance condition with the maximum resonance frequency point of the preset multi-degree-of-freedom resonant system, thereby amplifying the amplitude of the first output load to obtain the second output load.

5. The method for controlling fatigue testing of large-tonnage high-frequency electro-hydraulic servo resonance according to claim 1, characterized in that, The process of performing fatigue testing on the material specimen under test in the alternating load environment includes: The actual displacement signal and actual load signal of the test material sample are collected. Based on the actual displacement signal, the actual load signal, and the preset target load amplitude and / or target displacement amplitude, basic control commands are generated through a dual closed-loop control mechanism. A dynamic compensation signal is generated based on a preset compensation algorithm; the preset compensation algorithm is used to identify and predict the dynamic error caused by the nonlinear characteristics and time-varying parameters of the hydraulic servo system, and to generate a dynamic compensation signal based on the dynamic error. The basic control command and the dynamic compensation signal are fused to obtain the second target control command, which is then used to optimize the control of the material fatigue testing process.

6. The method for controlling fatigue testing of large-tonnage high-frequency electro-hydraulic servo resonance according to claim 1, characterized in that, The preset fatigue load loading system further includes a second load loading subsystem, which uses a servo motor as a power source to generate a third output load or a fourth output load; the third output load is a static average load of different load types, and the fourth output load is an output load whose frequency meets a preset low-frequency determination condition; the load types include tension, compression, and bending; wherein, the method further includes: According to the testing requirements of the material sample to be tested, the second load loading subsystem is controlled to generate the corresponding third or fourth output load; When the third output load is output, a static and dynamic composite load loading environment is constructed based on the third output load, the second output load, and the preset dual closed-loop control mechanism. The fatigue test of the test material sample is then performed in the static and dynamic composite load loading environment to obtain the fatigue test results of the test material sample. When the fourth output load is output, a low-frequency load loading environment is constructed based on the fourth output load and the preset dual closed-loop control mechanism, and fatigue testing is performed on the test material sample in the low-frequency load loading environment to obtain the fatigue test results of the test material sample.

7. The method for controlling high-tonnage high-frequency electro-hydraulic servo resonance fatigue tests according to any one of claims 1 to 6, characterized in that, Also includes: When the preset termination condition is met, the corresponding actuator is controlled to stop the load loading and reset, and the fatigue test results are output. The preset termination conditions include the current test cycle reaching the preset test cycle, or the test material sample reaching the preset mechanical property failure criterion, or any state signal in the state signals collected in the load loading environment exceeding the corresponding preset safe operation threshold. The preset safe operating thresholds include load over-limit thresholds and displacement over-limit thresholds.

8. A high-tonnage high-frequency electro-hydraulic servo resonant fatigue test control system, characterized in that, The system is applied to a preset fatigue load loading system, which includes a first load loading subsystem, comprising a preset hydrostatic support actuator and a preset multi-degree-of-freedom resonant system. The preset multi-degree-of-freedom resonant system includes a preset resonant amplification unit and a vibration system constructed based on multi-level weights and springs. The large-tonnage high-frequency electro-hydraulic servo resonant fatigue test control system includes: The first load generation module is used to generate a first output load through a preset hydrostatic support actuator; wherein, the first output load is an output load whose frequency meets a preset high frequency determination condition. The second load generation module is used to resonate and amplify the load component of the first output load using the vibration system and the preset resonant amplification unit to obtain the second output load. The fatigue testing module is used to construct an alternating load loading environment based on the second output load and in combination with a preset dual closed-loop control mechanism, and to perform fatigue testing on the test material sample in the alternating load loading environment to obtain the fatigue test results of the test material sample; wherein, the preset dual closed-loop control mechanism is a mechanism for performing dual closed-loop control on alternating displacement and / or load amplitude.

9. The large-tonnage high-frequency electro-hydraulic servo resonant fatigue test control system according to claim 8, characterized in that, The first load generation module further includes: The data acquisition unit is used to receive the fatigue test parameters set by the user through the human-computer interaction interface of the host computer, and to collect the initial signal using sensors arranged on the test material sample and related equipment. The format conversion unit is used to decompose and condition the initial signal to obtain the target feature signal, and convert the target feature signal from analog format to digital format to obtain the digital feature signal; The environment construction unit is used to call the corresponding control algorithm according to the preset core control architecture to calculate the digital characteristic signal and the fatigue test parameters, and generate a first target control instruction based on the calculation result, so as to control the corresponding execution unit to construct the alternating load loading environment based on the first target control instruction; the preset core control architecture is an embedded dual-core hardware architecture based on a field programmable gate array and a digital signal processor.

10. The large-tonnage high-frequency electro-hydraulic servo resonant fatigue test control system according to claim 8, characterized in that, The preset multi-degree-of-freedom resonant system corresponds to multiple natural frequencies, and different natural frequencies correspond to different resonance frequency points.

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