Static and dynamic integrated calibration system and method based on electromagnetic loading
The static and dynamic integrated calibration system constructed using an electromagnetic standard force loading device solves the problem of separating static and dynamic aspects in force testing equipment calibration, achieving high-precision, wide-bandwidth calibration, supporting in-situ calibration of large equipment, and improving the applicability and accuracy of calibration.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANJING UNIV OF SCI & TECH
- Filing Date
- 2026-03-02
- Publication Date
- 2026-05-12
AI Technical Summary
Existing force testing equipment calibration technologies suffer from problems such as separation of static and dynamic calibration, poor portability, limited accuracy of dynamic calibration, and the widespread phenomenon of "using static calibration in motion," which leads to significant errors in dynamic force measurement and makes it difficult to achieve high-precision, wide-bandwidth in-situ calibration.
An electromagnetic standard force loading device is used as a high-precision standard excitation source to construct an integrated and portable static and dynamic integrated calibration system, including an electromagnetic standard force loading device, a standard force sensor, a standard force generation and control module, a data acquisition module, a data processing unit, and a power drive module. Static and dynamic dual-mode calibration is achieved through closed-loop control.
It achieves high-precision, wide-bandwidth static and dynamic calibration, supports in-situ calibration of large force testing equipment, solves the portability and accuracy problems of calibration systems in traditional methods, and improves the applicability and accuracy of calibration.
Smart Images
Figure CN122016147A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of force testing device calibration technology, specifically relating to a static and dynamic integrated calibration system and method based on electromagnetic loading. Background Technology
[0002] Currently, the calibration of force testing equipment is mainly divided into two categories: static calibration and dynamic calibration. Static calibration technology is relatively mature, including weight-based calibration, mechanical calibration, and hydraulic calibration. Although these methods can achieve high static calibration accuracy, they generally suffer from problems such as load dispersion, inability to continuously adjust, and low degree of automation, and they are difficult to simulate the complex dynamic loads measured by force testing equipment in actual operation.
[0003] In terms of dynamic calibration, existing methods mainly include pulse excitation (such as drop hammer impact), step excitation (such as shock tubes and quick-opening valves), and periodic excitation (such as variable volumetric and piezoelectric stacked sinusoidal pressure generators). While pulse and step excitation methods can generate high-frequency excitation, they suffer from poor signal repeatability, low amplitude control accuracy, and short steady-state time, making accurate frequency domain characteristic analysis difficult. Although periodic excitation methods can generate continuously controllable sinusoidal signals, existing systems are often bulky, difficult to move, and have limited calibration amplitude and frequency. Furthermore, in-situ calibration of large force testing equipment at the test site is difficult, limiting their engineering applicability.
[0004] Furthermore, existing force testing equipment commonly suffers from the phenomenon of "static calibration followed by dynamic testing," meaning that dynamic testing is performed solely based on static calibration results, neglecting the frequency response differences of the force testing equipment under dynamic loads. This leads to significant errors in dynamic force measurement. With the increasing demands for force measurement accuracy in aerospace, robotics, and medical rehabilitation engineering, the development of an integrated calibration system that combines high precision, wide bandwidth, in-situ implementation, and the ability to simultaneously perform static and dynamic calibration of force testing equipment has become an urgent need in the field of force testing equipment calibration technology.
[0005] Electromagnetic standard force loading technology has advantages such as fast response, high control precision, controllable output waveform, and compact structure, and has been gradually applied in the fields of load simulation and hardware-in-the-loop simulation. Introducing it into the calibration system of force testing equipment can effectively overcome the limitations of traditional calibration methods, achieve high-precision and high-dynamic standard force excitation output, and provide more realistic and reliable calibration conditions for force testing equipment. Summary of the Invention
[0006] To address the technical bottlenecks in current force testing equipment calibration technologies, such as the separation of static and dynamic calibration, poor portability of dynamic calibration systems, limited accuracy of dynamic calibration, and significant errors in dynamic force measurement due to the prevalent phenomenon of "using static calibration as a tool," this invention aims to provide an integrated calibration system. This system solves the core technical challenges in the current force testing equipment calibration field, including the separation of static and dynamic calibration, limited calibration accuracy of small force testing equipment (strain gauge and piezoelectric force sensors), the inability of large force testing equipment (solid rocket propulsion testing platforms) to perform in-situ calibration, insufficient spatial force vector simulation capabilities, and the difficulty in maintaining high-precision calibration performance under wideband dynamic loading.
[0007] To achieve the above objectives, the technical solution adopted by this invention is as follows: a static and dynamic integrated calibration system and method based on electromagnetic loading. Its core lies in using an electromagnetic standard force loading device as a high-precision standard excitation source to construct an integrated, portable force testing equipment calibration system that supports both static and dynamic dual-mode calibration. The system mainly includes: an electromagnetic standard force loading device, a standard force sensor, a standard force generation and control module, a data acquisition module, a data processing unit, a power drive module, and a mechanical connection and support structure.
[0008] The electromagnetic standard force loading device is the core execution unit of the system, employing a moving-coil electromagnetic linear loading principle. Internally, it uses a Halbach permanent magnet array arranged on the inner wall of the outer yoke to enhance the magnetic field strength and uniformity of the working air gap. The coil frame, made of low-eddy-current loss titanium alloy, is placed within the air gap, and its surface is wound with reverse-connected electromagnetic coils. When current flows through the coil, an axial electromagnetic force is generated in the air gap magnetic field. This electromagnetic force is transmitted to a high-precision standard force sensor via an output push rod, thereby outputting a continuously adjustable standard static or dynamic force.
[0009] The data acquisition module includes at least four channels of 24-bit analog-to-digital converters (ADCs) for converting analog signals from the standard force sensor and the force testing equipment to be calibrated into digital signals.
[0010] The standard force generation and control module uses a high-performance floating-point DSP as its core processor. It is responsible for processing the feedback signals from the standard force sensor acquired by the data acquisition module in real time, running an advanced force control algorithm for the standard force loading device, and generating high-resolution PWM control commands. These commands are transmitted to the power drive module via optical fiber. The drive module uses a full-bridge inverter circuit to convert the commands into a precise voltage, which is then applied to the input terminal of the electromagnetic coil of the standard force loading device, forming a closed-loop force control.
[0011] The data processing unit has a data interface for communication with the data acquisition module, which is used to receive the actual loading force signal fed back by the standard force sensor and the measured force signal output by the force testing device to be calibrated, which are synchronously acquired by the data acquisition module.
[0012] The data processing unit integrates a calibration data processing program, which includes a calibration curve fitting module, a static performance analysis module, a dynamic characteristic analysis module, and an automatic report generation module.
[0013] The calibration curve fitting module generates a calibration curve including linear regression or piecewise interpolation based on the correspondence between the actual applied force signal and the measured force signal. The static performance analysis module calculates the sensitivity coefficient, nonlinear error, hysteresis error, and repeatability error of the force testing equipment to be calibrated. The dynamic characteristic analysis module performs frequency domain analysis on the amplitude ratio and phase difference under dynamic excitations such as sinusoidal signals to obtain the amplitude-frequency and phase-frequency characteristics of the force testing equipment to be calibrated. The data processing unit can format the above analysis results into a structured electronic calibration report according to a preset template.
[0014] Compared with the prior art, the significant advantages of this invention are:
[0015] (1) The static and dynamic integrated calibration system based on electromagnetic loading disclosed in this invention uses a moving-coil electromagnetic linear simulation loading device as the standard force loading device for the calibration system, realizing the simultaneous completion of static and dynamic calibration through a single calibration system, thus solving the problem of static and dynamic calibration separation in traditional methods. This standard force loading device can directly output high-precision static and dynamic standard electromagnetic forces by precisely controlling the amplitude and frequency of the input current. It has advantages such as high loading accuracy, rapid response, and compact structure, and performs outstandingly in terms of applicability, response speed, and calibration accuracy, effectively meeting the calibration needs of various force testing equipment.
[0016] (2) The static and dynamic integrated calibration system based on electromagnetic loading disclosed in this invention abandons the bulky and cumbersome structure of traditional dynamic calibration equipment and adopts a compact electromagnetic loading unit as the standard force loading device. All components are integrated into a movable test bench. This makes it possible to perform in-situ dynamic calibration of large, fixed force testing equipment, and completely solves the technical problems of long cycle, high cost and potential secondary installation errors caused by equipment disassembly, transportation and inspection. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of a static and dynamic integrated calibration system based on electromagnetic loading according to the present invention.
[0018] Figure 2This is a diagram illustrating the lateral force calibration architecture of a static and dynamic integrated calibration system based on electromagnetic loading, applied to a solid rocket motor thrust test platform.
[0019] Figure 3 This is a diagram illustrating the lateral torque calibration architecture of a static-dynamic integrated calibration system based on electromagnetic loading, applied to a solid rocket motor thrust test platform.
[0020] Figure 4 This is a schematic diagram of the standard force loading device of a static and dynamic integrated calibration system based on electromagnetic loading according to the present invention.
[0021] Figure 5 This is a schematic diagram of the standard force loading device structure of a static and dynamic integrated calibration system based on electromagnetic loading according to the present invention.
[0022] The reference numerals in the figure are respectively:
[0023] 1-Electromagnetic standard force loading device, 11-Outer magnetic yoke, 12-Inner magnetic yoke, 13-Permanent magnet array, 14-Coil frame, 15-Electromagnetic coil, 16-Output push rod.
[0024] 2-Standard force sensor, 3-Standard force generation control module, 4-Data acquisition module, 5-Data processing unit, 6-Power drive module, 7-Solid engine thrust test platform to be calibrated, 8-Simulated engine. Detailed Implementation
[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0026] The static and dynamic integrated calibration system and method based on electromagnetic loading disclosed in this invention solves the problems of separation of static and dynamic calibration in force testing equipment calibration systems, low accuracy of dynamic calibration under large loads, and difficulty in in-situ calibration of large force testing equipment.
[0027] An integrated static and dynamic calibration system based on electromagnetic loading includes an electromagnetic standard force loading device 1, a standard force sensor 2, a standard force generation and control module 3, a data acquisition module 4, a data processing unit 5, and a power drive module 6. The data acquisition module 4 is connected to the standard force sensor 2, the standard force generation and control module 3, the data processing unit 5, the power drive module 6, and the force testing equipment to be calibrated. The standard force generation and control module 3, the power drive module 6, the electromagnetic standard force loading device 1, the standard force sensor 2, and the force testing equipment to be calibrated are connected in sequence.
[0028] The standard force sensor 2 is connected to the output end of the electromagnetic standard force loading device 1.
[0029] The data acquisition module 4 is used to simultaneously acquire the actual loading force signal fed back by the standard force sensor 2 and the measured force signal output by the force testing device to be calibrated.
[0030] The standard force generation and control module 3 is used to set the target loading force parameters and receive the actual loading force signal from the data acquisition module 4, and generate control commands by running a closed-loop control algorithm.
[0031] The power drive module 6 is used to receive control commands from the standard force generation control module 3 and drive the electromagnetic standard force loading device 1 to output a precise and controllable standard electromagnetic force.
[0032] The data processing unit 5 is used to receive and process the actual applied force signal and the measured force signal from the data acquisition module 4, generate a calibration curve, obtain sensitivity, perform error analysis, and generate a calibration report.
[0033] The electromagnetic standard force loading device 1 includes an outer magnetic yoke 11, an inner magnetic yoke 12, a permanent magnet array 13, a coil frame 14, an electromagnetic coil 15, and an output push rod 16.
[0034] The permanent magnet array 13 adopts a Halbach magnetic circuit structure. The array is composed of radially magnetized permanent magnets and axially magnetized permanent magnets arranged alternately and attached to the inner circumferential surface of the outer magnetic yoke 11. It is used to form a high-intensity and uniformly distributed radial magnetic field in the air gap, while effectively reducing external magnetic leakage.
[0035] The inner magnetic yoke 12 is coaxially fixed inside the outer magnetic yoke 11, and an annular working air gap is formed between the outer cylindrical surface of the inner magnetic yoke 12 and the inner surface of the permanent magnet array 13.
[0036] The coil frame 14 is precision machined from high-strength, low-conductivity titanium alloy material and placed in the working air gap. Multiple annular winding grooves are opened on its outer surface. The electromagnetic coil 15 is wound in the winding grooves. The coil leads are connected to the power drive module 6 through the sealed interface at the end of the frame.
[0037] One end of the output push rod 16 is rigidly connected to the end of the coil frame 14 via a thread, and the other end extends outward through the center hole of the end cap of the outer magnetic yoke 11 and is connected to the standard force sensor 2.
[0038] When a controlled current is applied to the electromagnetic coil 15, it is subjected to an axial Lorentz force in the radial magnetic field of the air gap. The electromagnetic force is transmitted to the output push rod 16 through the coil frame, thereby outputting a high-precision standard electromagnetic force.
[0039] In the electromagnetic standard force loading device 1, the permanent magnet array 13 makes the magnetic flux density in the working air gap region significantly higher than that in the non-working region, thereby improving the output efficiency and thrust density of the electromagnetic force.
[0040] The connection between the coil frame 14 and the output push rod 16 is provided with a pre-tightening and anti-loosening structure to ensure reliable connection and no relative displacement during dynamic loading of large loads (-2000~2000N).
[0041] The number of electromagnetic standard force loading devices 1 is at least one, used to calibrate the unidirectional force testing equipment to be calibrated; when the number of electromagnetic standard force loading devices 1 is two or more, different loading devices can work independently to calibrate the unidirectional force testing equipment, or they can work together to achieve the coupling calibration of the multi-directional force channels of the multi-dimensional force testing equipment through combined loading.
[0042] The standard force generation control module 3 uses a closed-loop control algorithm to enable the electromagnetic standard force loading device 1 to output various waveform standard forces, including static force, step force, and sinusoidal force, thereby realizing integrated calibration of the static and dynamic characteristics of the force testing equipment to be calibrated.
[0043] The aforementioned electromagnetic loading-based static and dynamic integrated calibration system supports at least two calibration operating modes:
[0044] Unidirectional force calibration mode: At least one electromagnetic standard force loading device 1 applies a static or dynamic standard force along a single measurement direction of the force testing equipment to be calibrated.
[0045] Multidimensional force or torque composite calibration mode: Two electromagnetic standard force loading devices 1 work together to load the force. By adjusting their relative positions and force directions, they simulate spatial vector force or composite torque to achieve calibration of different measurement channels of the multidimensional force testing equipment.
[0046] The calibration report generated by the data processing unit 5 includes at least the following core performance parameters: sensitivity coefficient, nonlinear error, hysteresis error, repeatability error, uncertainty, and amplitude ratio and phase difference under dynamic calibration.
[0047] A calibration method for force testing equipment based on an integrated static and dynamic calibration system using electromagnetic loading includes the following steps:
[0048] S1: Set the waveform, amplitude and frequency parameters of the target loading force through the standard force generation control module 3, and initialize the data acquisition module 4 and the data processing unit 5.
[0049] S2: The standard force generation control module 3 runs a closed-loop control algorithm to enable the electromagnetic standard force loading device 1 to output a high-precision standard force according to the set loading parameters. The data acquisition module 4 simultaneously acquires the actual loading force signal fed back by the standard force sensor 2 and the output signal of the force testing equipment to be calibrated under the corresponding load, as follows:
[0050] The closed-loop control algorithm is implemented based on an RBF neural network, an adaptive PID controller, and a disturbance observer. The RBF neural network is used to dynamically identify the standard force loading device and obtain Jacobian information in real time. The adaptive PID controller dynamically adjusts the PID control parameters according to the Jacobian information. The disturbance observer is used to observe and estimate unknown disturbances such as eddy current disturbances and time-varying parameters that the system is subjected to in real time, and introduces the estimated values as feedforward compensation signals into the control channel to achieve active suppression of disturbances.
[0051] The target force signal is first input to the adaptive PID controller to generate an initial control command. The actual loading force signal acquired in real time by the data acquisition module 4 and the output control command of the adaptive PID controller are synchronously input to the RBF neural network for identification. The RBF neural network identifies the dynamic characteristics of the system online and outputs Jacobian information. The adaptive PID controller adjusts the PID control parameters in real time according to the Jacobian information and generates a corrected control command based on the target force and the actual loading force. The disturbance observer simultaneously receives the actual control command and the actual output force signal, estimates the external disturbances to the system, and adds the estimated value as a feedforward compensation to the control command. The final comprehensive control command is converted into the driving voltage of the standard force loading device 1 by the power drive module 6.
[0052] S3: Based on the actual loading force obtained by the data acquisition module 4 and the measured value of the test equipment to be calibrated, the data processing unit 5 automatically completes the calibration curve fitting, static performance index calculation, dynamic frequency response characteristic analysis, and generates a comprehensive calibration report including sensitivity, nonlinearity, repeatability and amplitude / phase error.
[0053] Example 1
[0054] The following embodiments use a solid rocket motor thrust test platform as an example to illustrate the calibration process of its lateral force and lateral moment measurement channels, which can also be extended to other types of force test equipment.
[0055] The solid rocket motor thrust test platform 7 to be calibrated adopts a classic four-point force measurement layout, with four high-precision triaxial strain gauge force sensors symmetrically installed at the four corners of the platform, forming a complete force measurement network. The data processing unit can calculate the signals from the four sensors in real time and accurately reconstruct the lateral force and lateral moment acting on the platform based on the space mechanics model.
[0056] Combination Figure 1 The static and dynamic integrated calibration system based on electromagnetic loading includes: an electromagnetic standard force loading device 1, a standard force sensor 2, a standard force generation and control module 3, a data acquisition module 4, a data processing unit 5, and a power drive module 6.
[0057] Among them, combined Figure 4 and Figure 5 The electromagnetic standard force loading device 1 is a moving-coil electromagnetic linear simulation loading device, including an outer magnetic yoke 11, an inner magnetic yoke 12, a permanent magnet array 13, a coil frame 14, an electromagnetic coil 15, and an output push rod 16. The permanent magnet array 13 adopts a Halbach magnetic circuit structure and is attached to the inner wall of the outer magnetic yoke 11 to form a high-intensity uniform magnetic field in the working air gap. The coil frame 14 is placed in the air gap, and the electromagnetic coil 15 is wound on the frame. When a controlled current is applied, it experiences an axial Lorentz force in the magnetic field, and outputs a standard electromagnetic force through the output push rod 16. In this embodiment, there are two electromagnetic standard force loading devices 1. The two devices can work independently to calibrate the unidirectional lateral force measurement channel, or they can work together to achieve coupled calibration of the lateral torque measurement channel of the thrust test platform.
[0058] The standard force sensor 2 is connected in series at the output end of the electromagnetic standard force loading device 1, and is used to measure the actual force applied to the force testing equipment to be calibrated in real time, serving as the reference standard force for the calibration system. In this embodiment, the standard force sensor 2 is a high-precision piezoelectric force sensor with a range covering -3000N to 3000N, a sensitivity of not less than 3pC / N, and a natural frequency higher than 5kHz, suitable for accurate measurement of static and dynamic forces. Two sensors are used, corresponding to two electromagnetic standard force loading devices 1 respectively.
[0059] The standard force generation control module 3 is used to set the waveform, amplitude, frequency, and calibration mode parameters of the target loading force, and runs a closed-loop control algorithm to generate a PWM control signal to be sent to the power drive module 6. In this embodiment, the standard force generation control module 3 uses a high-performance floating-point digital signal processor as its core, supporting the output of various waveforms such as static force, step force, and sinusoidal force, realizing integrated calibration of the force testing equipment to be calibrated from static to dynamic. The system can achieve a standard force loading range of -2000 to 2000N, a dynamic calibration frequency of over 40Hz, and a steady-state loading error of less than 1%.
[0060] The power drive module 6 receives the PWM control signal output by the standard force generation control module 3, and after power amplification, provides a drive voltage with controllable amplitude and frequency for the electromagnetic standard force loading device 1. In this embodiment, the power drive module 6 adopts an IGBT-based full-bridge inverter topology, and integrates drive circuits, protection logic, and fiber optic communication interfaces. It has fault detection functions such as overcurrent, overvoltage, and overheating. When a fault is triggered, the drive signal is immediately blocked and an alarm message is sent.
[0061] The data acquisition module 4 is used to simultaneously acquire the actual applied force signal fed back by the standard force sensor 2 and the measured force signal output by the force testing device to be calibrated. In this embodiment, the data acquisition module 4 integrates a multi-channel synchronous sampling high-precision analog-to-digital converter with a maximum sampling rate of 200KHz, supporting multi-channel parallel acquisition. The acquired data is transmitted to the standard force generation control module 3 for closed-loop control and to the data processing unit 5 for subsequent analysis.
[0062] The data processing unit 5 is equipped with a data interface that communicates with the data acquisition module 4, used to receive synchronously acquired actual loading force signals and measured force signals. The data processing unit 5 integrates a calibration data processing program, which includes a calibration curve fitting module, a static performance analysis module, a dynamic characteristic analysis module, and an automatic report generation module. Specifically, the calibration curve fitting module generates a calibration curve including linear regression; the static performance analysis module calculates sensitivity coefficients, nonlinear errors, hysteresis errors, and repeatability errors; the dynamic characteristic analysis module performs frequency domain analysis on the amplitude ratio and phase difference under sinusoidal excitation to obtain amplitude-frequency and phase-frequency characteristics; and the automatic report generation module formats the analysis results into a structured electronic calibration report. In this embodiment, the data processing unit 5 is implemented by an industrial control computer, running dedicated calibration system monitoring software and providing a graphical human-machine interface.
[0063] Combination Figure 2 and Figure 3The solid rocket motor thrust test platform 7 is bolted to the engine thrust measurement test bench. The simulated engine 8 is connected to the thrust test platform via bolts. It receives the loading force and torque from the standard force loading device 1 and transmits the received static and dynamic force signals to the thrust test platform via bolts. Eight square grooves are provided at different heights of the simulated engine for fixing the connecting flange. The output push rod of the standard force loading device 1 is connected to the standard force sensor 2 via a connecting shaft. The standard force sensor 2 outputs standard electromagnetic force to the simulated engine 8 via the connecting flange. The support structure uses height-adjustable supports, allowing two of the standard force loading devices 1 to be flexibly positioned vertically. By adjusting their height, the system can quickly switch between "lateral force calibration mode" and "lateral torque calibration mode" without changing the hardware connections.
[0064] Combination Figure 2 In the lateral force calibration mode of the solid rocket motor thrust test platform 7, two standard force loading devices 1 are orthogonally arranged in the horizontal plane, pointing towards the X-axis and Y-axis of the thrust test platform 7, respectively. The output shafts of the standard force loading devices 1 are connected to the simulated engine 8 fixed on the thrust test platform 7 through their respective standard force sensors 2 and connecting flanges. During calibration, the standard force generation control module 3 sets the target force signal and drives the two standard force loading devices 1 to output the specified static or dynamic standard electromagnetic force through the power drive module 6, and the actual applied force value is measured by the standard force sensor 2. At the same time, the data acquisition module 4 acquires the output signals of the standard force sensor 2 and the four triaxial force sensors of the thrust test platform 7, and calculates the lateral force component measured by the platform. The data processing unit 5 completes the calibration of the static characteristics such as sensitivity and linearity of the lateral force measurement channel of the thrust test platform 7, as well as the analysis of the dynamic characteristics, by comparing the standard force measured by the standard force sensor 2 with the measured force of the thrust test platform 7.
[0065] Combination Figure 3 In the lateral torque calibration mode of the solid rocket motor thrust test platform 7, the support of one side of the standard force loading device is raised, so that the two standard force loading devices 1 act on different height points in the vertical direction of the simulated engine 8. The two standard force loading devices 1 output electromagnetic forces of equal magnitude and opposite direction, thus forming a standard static or dynamic torque load. The lateral torque on the thrust test platform 7 can be calculated based on the output signals of its four force measuring elements in the Z direction. By comparing the theoretically applied torque (standard force × lever arm) with the torque calculated by the thrust test platform, the calibration of its lateral torque measurement channel can be achieved. The lever arm of the standard torque output by the standard force loading device 1 is the distance between the centers of the grooves in the simulated engine 8. Taking the lateral torque in the X direction as an example, the actual measured torque of the thrust test platform 7... The calculation formula is as follows:
[0066] ,
[0067] In the formula, 'a' represents half the distance between the force measuring units of the solid rocket motor thrust test platform 7, and F... z1 F z2 F z3 F z4 These are the Z-direction force components measured by each force measuring unit.
[0068] In terms of static calibration, compared with traditional static calibration systems (such as weight-based or hydraulic calibration systems), the electromagnetic loading-based integrated static and dynamic calibration system of this invention uses an electromagnetic standard force loading device, which is compact and highly portable. It can perform in-situ calibration of large force testing equipment at the test site, solving the problems of force value dispersion and difficulty in large load calibration of traditional static calibration systems, as well as the problems of large size, complex oil circuits and seals, and difficulty in mobile deployment of hydraulic systems. In terms of dynamic calibration, compared with traditional dynamic calibration systems (such as pulse-based, step-based, or periodic calibration systems), the electromagnetic loading-based integrated static and dynamic calibration system of this invention can directly generate high-precision, continuously adjustable sine waves and other complex waveform standard forces, and has the characteristics of fast response speed, high loading accuracy, and strong waveform reproduction capability. The system has a compact structure and good portability, and can perform in-situ dynamic calibration of large force testing equipment at the test site, overcoming the limitations of traditional dynamic calibration systems that cannot be flexibly deployed. Meanwhile, the system supports wide-bandwidth and large-load dynamic loading, and exhibits high accuracy in dynamic amplitude and phase control. It can effectively evaluate the effective sensitivity and dynamic response characteristics of various force testing equipment at different frequencies, providing a more reliable and convenient calibration method for various force testing equipment.
[0069] In summary, this system integrates electromagnetic direct-drive loading, multi-physics collaborative design, precision mechanical structure, real-time closed-loop control, and digital signal processing to achieve integrated and highly repeatable calibration of the static and dynamic performance of force testing equipment.
[0070] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A static and dynamic integrated calibration system based on electromagnetic loading, characterized in that: It includes an electromagnetic standard force loading device (1), a standard force sensor (2), a standard force generation control module (3), a data acquisition module (4), a data processing unit (5), and a power drive module (6); the data acquisition module (4) is connected to the standard force sensor (2), the standard force generation control module (3), the data processing unit (5), the power drive module (6), and the force testing equipment to be calibrated, respectively; the standard force generation control module (3), the power drive module (6), the electromagnetic standard force loading device (1), the standard force sensor (2), and the force testing equipment to be calibrated are connected in sequence; The standard force sensor (2) is connected to the output end of the electromagnetic standard force loading device (1); The data acquisition module (4) is used to synchronously acquire the actual loading force signal fed back by the standard force sensor (2) and the measured force signal output by the force testing device to be calibrated; The standard force generation control module (3) is used to set the target loading force parameters and receive the actual loading force signal from the data acquisition module (4), and generate control commands by running a closed-loop control algorithm; The power drive module (6) is used to receive control commands from the standard force generation control module (3) and drive the electromagnetic standard force loading device (1) to output a precise and controllable standard electromagnetic force. The data processing unit (5) is used to receive and process the actual loading force signal and the measured force signal from the data acquisition module (4), generate a calibration curve, obtain sensitivity, perform error analysis, and generate a calibration report.
2. The static and dynamic integrated calibration system based on electromagnetic loading according to claim 1, characterized in that: The electromagnetic standard force loading device (1) includes an outer magnetic yoke (11), an inner magnetic yoke (12), a permanent magnet array (13), a coil frame (14), an electromagnetic coil (15), and an output push rod (16); The permanent magnet array (13) adopts a Halbach magnetic circuit structure. The array is composed of radially magnetized permanent magnets and axially magnetized permanent magnets arranged alternately and attached to the inner circumferential surface of the outer magnetic yoke (11) to form a high-intensity and uniformly distributed radial magnetic field in the air gap, while effectively reducing external magnetic leakage. The inner magnetic yoke (12) is coaxially fixed inside the outer magnetic yoke (11), and an annular working air gap is formed between the outer cylindrical surface of the inner magnetic yoke (12) and the inner surface of the permanent magnet array (13). The coil frame (14) is made of high-strength, low-conductivity titanium alloy material and is precision machined. It is placed in the working air gap and has multiple annular winding grooves on its outer surface. The electromagnetic coil (15) is wound in the winding grooves and the coil leads are connected to the power drive module (6) through the sealed interface at the end of the frame. One end of the output push rod (16) is rigidly connected to the end of the coil frame (14) by a thread, and the other end extends outward through the center hole of the end cap of the outer magnetic yoke (11) and is connected to the standard force sensor (2). When a controlled current is applied to the electromagnetic coil (15), it is subjected to an axial Lorentz force in the radial magnetic field of the air gap. The electromagnetic force is transmitted to the output push rod (16) through the coil frame, thereby outputting a high-precision standard electromagnetic force.
3. The static and dynamic integrated calibration system based on electromagnetic loading according to claim 2, characterized in that: In the electromagnetic standard force loading device (1), the permanent magnet array (13) makes the magnetic flux density in the working air gap region significantly higher than that in the non-working region, thereby improving the output efficiency and thrust density of the electromagnetic force. The connection between the coil frame (14) and the output push rod (16) is provided with a pre-tightening and anti-loosening structure to ensure reliable connection and no relative displacement during dynamic loading of large loads.
4. The static and dynamic integrated calibration system based on electromagnetic loading according to claim 1, characterized in that: The number of electromagnetic standard force loading devices (1) is at least one, used to calibrate the unidirectional force testing equipment to be calibrated; when the number of electromagnetic standard force loading devices (1) is two or more, different loading devices can work independently to calibrate the unidirectional force testing equipment, or work together to achieve the coupling calibration of the multi-directional force channels of the multi-dimensional force testing equipment through combined loading.
5. The static and dynamic integrated calibration system based on electromagnetic loading according to claim 4, characterized in that: The standard force generation control module (3) enables the electromagnetic standard force loading device (1) to output various waveform standard forces, including static force, step force, and sinusoidal force, through a closed-loop control algorithm, thereby realizing the integrated calibration of the static and dynamic characteristics of the force testing equipment to be calibrated.
6. The static and dynamic integrated calibration system based on electromagnetic loading according to claim 5, characterized in that, The system supports at least two calibration operating modes: Unidirectional force calibration mode: At least one electromagnetic standard force loading device (1) applies a static or dynamic standard force along a single measurement direction of the force testing equipment to be calibrated; Multidimensional force or torque composite calibration mode: Two electromagnetic standard force loading devices (1) work together to load, and by adjusting their relative positions and force directions, they simulate spatial vector force or composite torque to achieve calibration of different measurement channels of the multidimensional force testing equipment.
7. The static and dynamic integrated calibration system based on electromagnetic loading according to claim 1, characterized in that: The calibration report generated by the data processing unit (5) includes at least the following core performance parameters: sensitivity coefficient, nonlinear error, hysteresis error, repeatability error, uncertainty, and amplitude ratio and phase difference under dynamic calibration.
8. A calibration method for a force testing device based on the integrated static and dynamic calibration system based on electromagnetic loading as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1: Set the waveform, amplitude and frequency parameters of the target loading force through the standard force generation control module (3), and initialize the data acquisition module (4) and data processing unit (5); S2: The standard force generation control module (3) runs a closed-loop control algorithm to enable the electromagnetic standard force loading device (1) to output a high-precision standard force according to the set loading parameters. The data acquisition module (4) synchronously acquires the actual loading force signal fed back by the standard force sensor (2) and the output signal of the force testing equipment to be calibrated under the corresponding load. S3: Based on the actual loading force obtained by the data acquisition module (4) and the measured value of the test equipment to be calibrated, the data processing unit (5) automatically completes the calibration curve fitting, static performance index calculation, dynamic frequency response characteristic analysis, and generates a comprehensive calibration report including sensitivity, nonlinearity, repeatability and amplitude / phase error.
9. A calibration method for a force testing device based on the integrated static and dynamic calibration system based on electromagnetic loading as described in claim 8, characterized in that, In S2, the details are as follows: The closed-loop control algorithm is based on RBF neural network, adaptive PID controller and disturbance observer. RBF neural network is used to dynamically identify standard force loading device and obtain Jacobian information in real time. The adaptive PID controller dynamically adjusts the PID control parameters based on Jacobian information; the disturbance observer is used to observe and estimate unknown disturbances such as eddy current disturbances and time-varying parameters that the system is subjected to in real time, and introduces the estimated values as feedforward compensation signals into the control channel to achieve active suppression of disturbances. The target force signal is first input to the adaptive PID controller to generate initial control commands; The actual loading force signal acquired in real time by the data acquisition module (4) and the output control command of the adaptive PID controller are synchronously input to the RBF neural network for identification. The RBF neural network identifies the dynamic characteristics of the system online and outputs Jacobian information. The adaptive PID controller adjusts the PID control parameters in real time according to the Jacobian information and generates a corrected control command based on the target force and the actual loading force. The disturbance observer simultaneously receives the actual control command and the actual output force signal, estimates the external disturbances to the system, and adds the estimated value as a feedforward compensation to the control command. The final integrated control command is converted into the driving voltage of the standard force loading device (1) by the power drive module (6).