Six-component force resolution method and system for a prismatic force platform
By calibrating the signal channels of the frustum-shaped force measuring stage in groups and selecting the signal channels with normal combinations, the response signal matrix and calibration matrix are obtained. This solves the problem of recalibration required for abnormal signal channels in the prior art, realizes fault-tolerant measurement, and improves the reliability and measurement accuracy of the system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SUN YAT SEN UNIV
- Filing Date
- 2026-02-03
- Publication Date
- 2026-06-12
Smart Images
Figure CN122192600A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of force measuring table technology, and in particular to a six-component force analysis method and system for a frustum-shaped force measuring table. Background Technology
[0002] In related technologies, micro-vibration force measuring tables typically employ four triaxial force sensors arranged at four edge support points at the bottom of the mounting platform to achieve a 12-channel signal output matrix. By multiplying the calibration matrix by the signal output matrix, the six-component disturbance force at the center point of the mounting platform can be obtained.
[0003] When calibrating the force measuring table, a known standard load is applied to the force measuring table. The actual component force matrix of the standard load and the signal matrix output by the force measuring table are converted to obtain a 6×k calibration matrix, where k represents the number of signal channels.
[0004] The 12-channel micro-vibration force measuring table does not have redundancy and fault tolerance. All channels must participate in matrix operations. If the signal of one channel is abnormal, the micro-vibration force measuring table will be unable to measure the disturbance force.
[0005] Existing force stations increase the number of signal channels by incorporating more force sensors, thereby improving measurement tolerance. However, if data from one signal channel becomes abnormal, the force station needs to be calibrated to recalculate the calibration matrix. The more signal channels there are, the greater the potential risk of signal channel anomalies, necessitating calibration of the force station before each vibration experiment to prevent potential signal channel anomalies from affecting the measurement results. Summary of the Invention
[0006] The main objective of this application is to propose a six-component force analysis method and system for a frustum-shaped force measuring stage, which can perform six-component force analysis without recalibration, achieve fault-tolerant measurement, and improve system reliability.
[0007] To achieve the above objectives, this application proposes a six-component force analysis method for a frustum-shaped force measuring stage, comprising the following steps:
[0008] Several signal channel combinations are obtained, and the signal channel combinations are calibrated to determine the calibration matrix corresponding to each signal channel combination; the signal channel combinations are obtained by grouping the signal channels of the force measuring table. Select the signal channel combination with normal signal channels, and obtain the response signal matrix and the calibration matrix; The six-component forces are determined based on the response signal matrix and the calibration matrix.
[0009] In some embodiments, the calibration of the plurality of signal channel combinations to determine the calibration matrix corresponding to each signal channel combination specifically includes: A standard load is applied to several calibration points of the force measuring table to obtain the excitation signal matrix of the calibration points and the response signal matrix of each signal channel combination. The excitation signal matrix is transformed based on the spatial transformation relationship of the calibration points to obtain the true force components; Matrix transformation is performed on each of the response signal matrices based on the actual force components to obtain calibration matrices corresponding to several signal channel combinations.
[0010] In some embodiments, calibrating the plurality of signal channel combinations to determine the calibration matrix corresponding to each signal channel combination further includes: The response signal phase is determined based on the response signal matrix, and the excitation signal phase of each calibration point is determined based on the excitation signal matrix. The phase difference between each calibration point is determined based on the phase of the response signal and the phase of the excitation signal. It is then determined whether the phase difference is within a preset range. If yes, the calibration point is determined as a qualified calibration point; otherwise, the calibration point is determined as an abnormal calibration point. The signal data of the abnormal calibration points are removed.
[0011] In some embodiments, the calibration points include verification points; After performing matrix transformation on each of the response signal matrices based on the true force components to obtain calibration matrices corresponding to the combinations of several signal channels, the method further includes: The calibration matrix is verified, specifically including: The measured value is determined based on the response signal matrix and the calibration matrix; The actual value is determined based on the excitation signal matrix of the verification point; Based on the relative error between the measured value and the actual value, the matrix with the smallest relative error is selected as the optimal calibration matrix.
[0012] In some embodiments, the step of transforming the excitation signal matrix based on the spatial transformation relationship of the calibration points to obtain the true force components specifically includes: A spatial coordinate system is constructed with the center point of the force measuring platform, and the spatial force system transformation matrix is determined according to the spatial coordinates of the calibration point in the spatial coordinate system. The force component of the marker point is determined based on the excitation signal matrix of the calibrated point. The actual force components are calculated based on the force components at the identified points and the spatial force system transformation matrix.
[0013] In some embodiments, applying standard loads to a plurality of calibration points of the force measuring table specifically includes: Using signals of sinusoidal functions of multiple different frequencies as input, the exciter is driven to generate the standard load of multiple frequencies perpendicular to the plane where the calibration point is located.
[0014] To achieve the above objectives, embodiments of this application also provide a six-component force analysis system for a frustum-shaped force measuring stage, the system comprising: The acquisition module is used to acquire the response signal output by the force measuring table and the excitation signal of the calibration point on the force measuring table; The excitation module is used to apply a standard load to the calibration point. The parsing module is used to execute the six-component force parsing method described in the embodiments of this application.
[0015] In some embodiments, the excitation module includes: A vibrator is used to apply a standard load to the calibration point. A drive circuit is used to drive the exciter according to the signal input.
[0016] To achieve the above objectives, this application also provides a six-component force analysis system for a frustum-shaped force measuring stage. The system includes a processor and a memory, the memory storing executable code. When the executable code is executed by the processor, it implements the six-component force analysis method described in this application.
[0017] To achieve the above objectives, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the six-component force analysis method described in this application.
[0018] The embodiments of this application include at least the following beneficial effects: This application provides a six-component force analysis method and system for a frustum-shaped force measuring stage. The method involves grouping several signal channels of the force measuring stage, calibrating the resulting combinations of signal channels to obtain calibration matrices for each combination; selecting the signal channel combinations with normal signal channels to obtain a response signal matrix and the calibration matrix; and determining the six-component forces based on the calibrated response signal matrix and the calibration matrix. By grouping the signal channels of the force measuring stage and calibrating the calibration matrices for different signal channel combinations, the method allows for the selection of signal channel combinations with normal signal channels even when any single or multiple channels fail, enabling six-component force analysis without recalibration. This achieves fault-tolerant measurement and improves system reliability. Attached Figure Description
[0019] Figure 1This is an optional flowchart of the method shown in the embodiments of this application; Figure 2 This is a flowchart illustrating the calibration steps in the method shown in the embodiments of this application; Figure 3 This is a flowchart illustrating the abnormal calibration point identification step of the method shown in the embodiments of this application; Figure 4 This is a flowchart illustrating the calibration matrix verification step of the method shown in the embodiments of this application; Figure 5 This is a flowchart illustrating step 202 of the method shown in the embodiment of this application; Figure 6 This is a schematic diagram of the logical structure of the system shown in the embodiments of this application; Figure 7 This is a three-dimensional structural diagram of the system shown in the embodiments of this application; Figure 8 This is a three-dimensional structural diagram of the frustum-shaped force measuring table provided in the embodiments of this application; Figure 9 This is a three-dimensional structural diagram of the suspension device provided in the embodiments of this application. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application; they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.
[0021] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various concepts, but unless otherwise stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the words “if,” “when,” or “in response to a determination” as used herein may be interpreted as “when…” or “when…” or “in response to a determination.”
[0022] As used in this application, the terms "at least one", "multiple", "each", "any", etc., "at least one" includes one, two or more, "multiple" includes two or more, "each" refers to each of the corresponding multiples, and "any" refers to any one of the multiples.
[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.
[0024] In related technologies, micro-vibration force measuring tables typically employ four triaxial force sensors arranged at four edge support points at the bottom of the mounting platform to achieve a 12-channel signal output matrix. By multiplying the calibration matrix by the signal output matrix, the six-component disturbance force at the center point of the mounting platform can be obtained.
[0025] When calibrating the force measuring table, a known standard load is applied to the force measuring table. The actual component force matrix of the standard load and the signal matrix output by the force measuring table are converted to obtain a 6×k calibration matrix, where k represents the number of signal channels.
[0026] The 12-channel micro-vibration force measuring table does not have redundancy and fault tolerance. All channels must participate in matrix operations. If the signal of one channel is abnormal, the micro-vibration force measuring table will be unable to measure the disturbance force.
[0027] Existing force stations increase the number of signal channels by incorporating more force sensors, thereby improving measurement tolerance. However, if data from one signal channel becomes abnormal, the force station needs to be calibrated to recalculate the calibration matrix. The more signal channels there are, the greater the potential risk of signal channel anomalies, necessitating calibration of the force station before each vibration experiment to prevent potential signal channel anomalies from affecting the measurement results.
[0028] In view of this, embodiments of this application provide a six-component force analysis method and system for a frustum-shaped force measuring stage. This scheme groups the signal channels during calibration and calculates the calibration matrix of each channel combination separately, ensuring that if any single or multiple channels fail, the calibration matrix of the available channel combinations can be re-selected to measure the six-component force.
[0029] Figure 1 This is an optional flowchart of the six-component force analysis method for a frustum-shaped force measuring table provided in the embodiments of this application. Figure 1 The method may include, but is not limited to, steps 101 to 103; Step 101: Obtain several signal channel combinations, and calibrate the several signal channel combinations to determine the calibration matrix corresponding to each signal channel combination; the signal channel combinations are obtained by grouping the several signal channels of the force measuring table; Step 102: Select the signal channel combination with normal signal channels, and obtain the response signal matrix and the calibration matrix; Step 103: Determine the six-component forces based on the response signal matrix and the calibration matrix.
[0030] It is understood that the force measuring platform has K signal channels, and each combination of signal channels has at least 6 signal channels, where K is an integer greater than or equal to 6. If the force measuring platform is equipped with N force measuring rings, then it has... There are 1 signal channel, where N is an integer greater than or equal to 2. .
[0031] The response signal matrix is obtained by acquiring forces in three directions through each signal channel on the force measuring platform. The excitation signal at the calibration point is acquired by a unidirectional force sensor installed at the calibration point. The vibrator is connected to the force sensor via a push rod, and the force sensor is attached to the calibration point. When the force measuring platform is excited, the unidirectional force sensor can acquire the excitation signal at each calibration point.
[0032] In this embodiment, the signal channels of the force measuring stage are grouped, and calibration matrices for different combinations of signal channels are calibrated respectively. Even if any single or multiple channels fail, the system can still select the combination of signal channels with normal signal channels to perform six-component force analysis without recalibration, thus achieving fault-tolerant measurement and improving system reliability.
[0033] Figure 2 This is a flowchart illustrating the calibration steps in the method shown in the embodiments of this application.
[0034] See Figure 2 In some embodiments, the calibration of the plurality of signal channel combinations to determine the calibration matrix corresponding to each signal channel combination includes, but is not limited to: Step 201: Apply standard loads to several calibration points of the force measuring table, and obtain the excitation signal matrix of each calibration point and the response signal matrix of each signal channel combination; Step 202: Based on the spatial transformation relationship of the calibration points, transform the excitation signal matrix to obtain the true force components; Step 203: Perform matrix conversion on each of the response signal matrices according to the true force components to obtain calibration matrices corresponding to several signal channel combinations.
[0035] In this embodiment, during the calibration of the force measuring platform, several signal channels of the platform are grouped to obtain different signal channel combinations. When the force measuring platform is excited by a standard load, the signal channels respond to the excitation and output voltage signals, and output the response signal matrix corresponding to each combination according to the signal channel combination. Simultaneously, force sensors are installed at calibration points on the force measuring platform to collect the excitation output voltage signals at each of the marked points, obtaining an excitation signal matrix. Based on the spatial transformation relationship between the marked points and the center point of the test platform, the component force of the excitation signal matrix at the current marked point is calculated according to the excitation signal matrix, and the true force component at the center point in the force measuring platform reference frame is obtained. The response signal matrix is converted using the true force component to obtain calibration matrices for different signal channels. During force measuring, the combination of all normally functioning signal channels is selected to analyze and obtain six force components.
[0036] In some embodiments, the method further includes an abnormal calibration point identification step before step 202.
[0037] Figure 3 This is a flowchart illustrating the abnormal calibration point identification step of the method shown in the embodiments of this application.
[0038] See Figure 3 Anomaly identification includes, but is not limited to: 301. Determine the phase of the response signal based on the response signal matrix, and determine the phase of the excitation signal for each calibration point based on the excitation signal matrix; 302. Determine the phase difference of each calibration point based on the phase of the response signal and the phase of the excitation signal, and determine whether the phase difference is within a preset range. If yes, determine the calibration point as the qualified calibration point; if no, determine the calibration point as the abnormal calibration point. 303. Remove the signal data from the abnormal calibration points.
[0039] In this embodiment, non-compliant calibration points in the calibration system are excluded. For example, the standard load applied to the calibration point is F, and the voltage signal of the i-th channel is... Their phase difference is .
[0040] like If the voltage output by the signal channel of the force measuring table is in phase with the standard load, then the voltage output by the force measuring table is in phase with the standard load. like If the voltage output from the signal channel of the force measuring table is out of phase with the standard load, then the voltage output from one or more channels is out of phase with the standard load. It is not within these three intervals, and the voltage amplitude of this channel is... If the voltage amplitude of a point falls within the top 85% of the k channels, the data at that calibration point will be excluded and not used in subsequent calculations.
[0041] In some embodiments, after step 204, the calibration matrix is further verified.
[0042] Figure 4 This is a flowchart illustrating the calibration matrix verification steps of the method shown in the embodiments of this application.
[0043] See Figure 4 Verification of the calibration matrix specifically includes, but is not limited to, the following: 401. Determine the measured value based on the response signal matrix and the calibration matrix; 402. Determine the actual value based on the excitation signal matrix of the verification point; 403. Based on the relative error between the measured value and the actual value, select the matrix with the smallest relative error as the optimal calibration matrix.
[0044] In this embodiment, calibration point data with abnormal force and voltage phase differences are first eliminated. Then, the calibration matrices generated by all combinations under all channel number selections are filtered to obtain the calibration matrix with the smallest relative error for actual measurement, thereby minimizing measurement error. Simultaneously, parallel force loops can improve the sensitivity and signal-to-noise ratio of each channel, further enhancing measurement accuracy.
[0045] Figure 5 This is a flowchart illustrating step 202 of the method shown in the embodiment of this application.
[0046] See Figure 5 In some embodiments, step 202 may include, but is not limited to: 501. Construct a spatial coordinate system with the center point of the force measuring platform, and determine the spatial force system transformation matrix according to the spatial coordinates of the calibration point in the spatial coordinate system; 502. Determine the force component of the marker point based on the excitation signal matrix of the calibrated point; 503. Calculate the actual force components based on the force components at the identified points and the spatial force system transformation matrix.
[0047] The calibration process is achieved by applying known excitations to the calibration points of the platform and testing the output voltage signal of the signal channel combination. According to the principle of spatial force system simplification, transforming the calibration points to the equivalent center point requires multiplying by a transformation matrix.
[0048] Specifically, the force measuring platform is equipped with several force measuring rings, and each force measuring ring is equipped with a force sensor with several signal channels for outputting response signals. The signal channels are grouped in several ways, including spatial coordinate distribution combinations and parallel connections to form force measuring ring combinations before grouping.
[0049] In some embodiments, grouping the signal channels of the force measuring platform includes: grouping them according to the spatial coordinate distribution of the force measuring rings.
[0050] In some embodiments, the signal channels of several force-measuring rings on the same inclined surface of the force-measuring platform are connected in parallel to form a force-measuring ring combination.
[0051] In this embodiment, grouping the signal channels of the force measuring platform further includes grouping the force measuring ring combination to obtain the signal channel combination.
[0052] In some embodiments, applying standard loads to several calibration points of the force measuring table specifically includes: using signals of sinusoidal functions of multiple different frequencies as inputs to drive an exciter to generate standard loads of multiple frequencies perpendicular to the plane where the calibration points are located.
[0053] Figure 6 This is a schematic diagram of the logical structure of the system described in the embodiments of this application.
[0054] To achieve the above objectives, this application also provides a six-component force analysis system for a frustum-shaped force measuring stage, the system comprising: The acquisition module is used to acquire the response signal output by the force measuring table and the excitation signal of the calibration point on the force measuring table; The excitation module is used to apply a standard load to the calibration point. A parsing module is used in the methods described in the embodiments of this application.
[0055] In some embodiments, the excitation module includes: a vibrator for applying a standard load to the calibration point; and a drive circuit for driving the vibrator according to a signal input.
[0056] To achieve the above objectives, this application also provides a six-component force analysis system for a frustum-shaped force measuring stage. The system includes a processor and a memory, the memory storing executable code. When the executable code is executed by the processor, it implements the six-component force analysis method described in this application.
[0057] To achieve the above objectives, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the six-component force analysis method described in this application.
[0058] The method shown in the embodiments of this application will be described below with reference to a specific frustum-shaped force measuring table.
[0059] Figure 7 This is a three-dimensional structural diagram of the six-component force analysis system provided in the embodiments of this application; Figure 8 This is a three-dimensional structural diagram of the force measuring table provided in the embodiments of this application; Figure 9 This is a three-dimensional structural diagram of the suspension device provided in the embodiments of this application.
[0060] Attached diagram labels: 1. Frustum-shaped force measuring platform; 2. Center calibration plate; 3. Corner calibration block; 4. Force measuring ring; 5. Power amplifier; 6. High-performance target real-time machine; 7. Computer; 8. Charge amplifier; 9. Support suspension device; 10. Vibrator; 11. Top rod; 12. Force sensor; 901. Support rod; 902. Crossbar; 903. Slip ring; 904. Elastic rope.
[0061] See Figure 8 The load platform of the frustum-shaped force measuring table is frustum-shaped, including... Several force-measuring rings are evenly distributed in a ring shape on the load platform. On each of the inclined planes, install There are 10 force-measuring rings in total. One signal channel, of which , , The highly redundant signal channels provide the hardware foundation for the six-component force analysis method, effectively improving system reliability.
[0062] The following example uses a regular hexagonal frustum-shaped load platform. , k=48.
[0063] This application provides a six-component force analysis method, including the following steps: Step 1: As Figure 7 As shown, a distributed calibration fixture, including a central calibration plate and corner calibration blocks, is installed on the load platform of a frustum-shaped force measuring table. The calibration fixture is selected from... A calibration point for providing external incentives, and No less than indivual, and The number of direction calibration points is the same; Step 2: Select A coordinate system is established with the center of the upper surface of the load platform as the origin, using the selected calibration points as the reference points. Spatial coordinates of the calibration points to be measured ; Step 3: As Figure 6 As shown, a six-component force analysis system is constructed, which includes a charge amplifier, a high-performance target real-time machine, a computer, a power amplifier, an exciter, a push rod, a force sensor, and a support suspension device.
[0064] The computer is equipped with self-developed six-component force analysis software, which can be used to control and acquire the output and input signals of the high-performance target real-time machine. The force measuring table signal channel is connected to a charge amplifier, which in turn connects to the high-performance target real-time machine. The high-performance target real-time machine is then connected to the computer, thus forming the output signal acquisition circuit. The high-performance target real-time machine is connected to a power amplifier, which in turn connects to a vibrator. The vibrator is vertically suspended by a support suspension device. The output end of the vibrator is elastically connected to a force sensor via a push rod. The force sensor is attached to the center of the calibration point of the calibration fixture and transmits the force signal back to the high-performance target real-time machine, thus forming the input signal supply and acquisition circuit.
[0065] Step 4: Use the six-component force analysis system to sequentially apply multi-frequency sinusoidal unidirectional excitation to the several calibration points to be measured, and collect the input signals of the force sensor of the six-component force analysis system and the 48-channel voltage signals output by the force measuring table; Step 5: Eliminate unqualified calibration points: Specifically, the standard load excitation applied to the force measuring table by the facility is: , No. The voltage signal of each channel is Their phase difference is , like Then the voltage and force are in phase; like Then the voltage and force are out of phase; If one or more channels exist It is not within these three intervals, and the voltage amplitude of this channel is... In The first 85% of the voltage amplitude of each channel is excluded from the calibration point and not used in subsequent calculations. Step 6: Based on the spatial coordinates of the calibration point, convert the multi-frequency sinusoidal unidirectional excitation input by the six-component force analysis system for the qualified calibration point into six-component force amplitudes relative to the origin of the coordinate system.
[0066] Let the spatial coordinates of the j-th calibration point be... The applied force is Then the six-component force is transformed to the origin of the coordinate system. for:
[0067] in, This is the transformation matrix of the spatial force system.
[0068] Step 7: Solve for the optimal calibration matrix.
[0069] Specifically, based on the six-component force amplitudes relative to the origin and the output voltage amplitude of the force measuring platform after conversion, since there are 48 signal channels, the signal channels are grouped (each group has at least 6 channels) by taking advantage of the high redundancy of the signal channels. Then, the calibration matrix of each frequency (multi-frequency sinusoidal unidirectional excitation will cause the force measuring platform to generate multiple frequency responses) under each group is calculated through matrix operations. After verification, the calibration matrix with the highest accuracy for each frequency is selected, which is the optimal calibration matrix. Step 8: Load the optimal calibration matrix for each frequency from Step 7 into the six-component force analysis software on the computer for later use. Select the optimal calibration matrix with the same or close frequency as the vibration frequency of the disturbance source for real-time measurement. The selected optimal calibration matrix... and the output voltage of the force measuring table Calculate the six-component disturbance force generated by the object under test. The calculation formula is as follows:
[0070] Furthermore, such as Figure 8 As shown, the distributed calibration fixture in step 1 includes a central calibration plate and four corner calibration blocks, all designed as a stepped shape with multiple cubes. The central calibration plate is installed at the center of the force measuring table and has a total of 64 calibrable points. The corner calibration blocks are installed at the four corners of the force measuring table, each with 13 calibrable points, for a total of 52 calibrable points. The calibration fixture has a total of 116 calibrable points, which can be hammered by a force hammer or excited by a vibrator to obtain a series of system transfer functions.
[0071] Furthermore, such as Figure 9 As shown, the support suspension device in step 3 is used to precisely adjust the spatial position of the vibrator, and a locking device is used to position it when it is adjusted to the preset position.
[0072] Specifically, the support suspension device includes two support rods, one crossbar, one slip ring, and one elastic rope. The two support rods are symmetrically placed on both sides of the force measuring platform. The two ends of the crossbar are slidably connected to the top of the support rods to achieve translation in the X direction. The slip ring is fully slidably connected to the crossbar to achieve translation in the Y direction. The elastic rope is adjustable in length and connected to the slip ring to achieve translation in the Z direction. This device improves the convenience and accuracy of calibration.
[0073] Furthermore, in order to achieve the multi-frequency sinusoidal unidirectional excitation in step 4, firstly, a signal with multiple sinusoidal functions of different frequencies superimposed is set as input in the six-component force analysis software on the computer. The number of superimposed sinusoidal functions and their frequency values can be freely adjusted according to the requirements. Then, the signal is transmitted to the power amplifier through the high-performance target real-time machine, which finally drives the exciter to generate multi-frequency sinusoidal unidirectional excitation perpendicular to the plane where the calibration point is located.
[0074] The method provided in this application can calibrate multiple frequencies at once, improving calibration efficiency, and when there are enough frequencies, it can fit a more accurate frequency response curve.
[0075] Furthermore, in step 7, the verification of the calibration matrix is achieved by calculating the relative error between the measured value and the actual applied value. The formula for the relative error is:
[0076] in, For measured values, To apply the value, the matrix with the smallest relative error is selected as the optimal calibration matrix.
[0077] Taking the case of non-parallel force ring mode as an example, the specific calculation process is as follows: When the object under test is mounted on a load platform and is working, the micro-vibrations generated by the moving parts will have a six-component disturbance force / torque. The force is applied to the equivalent center point of the moving parts and the load platform. The sixteen triaxial force sensors of the force measuring table will output forty-eight voltage signals. The purpose of calibration is to determine the conversion relationship between the voltage and the six-component disturbance force / torque for all channel number selections (6, 9, 12, 15, ..., 48). This conversion relationship is a matrix called the calibration matrix W.
[0078] Assume the number of channels selected is a variable. The calibration matrix of the test platform was obtained. Then, 6 components of disturbance force / torque and Channel voltage signal The conversion relationship between them is as follows: (1) The calibration process involves applying a known six-component force / torque excitation to the equivalent center point of the load platform and then... ( This is achieved by testing 6, 9, 12, 15, ..., 48 output voltage signals.
[0079] Using a vibrator on the load platform and its distributed tooling Each calibration point and A multi-frequency sinusoidal unidirectional known force is applied to each verification point, denoted as follows: (Diagonal matrix) (Diagonal matrix).
[0080] According to the principle of simplification of spatial force systems, it can be seen that... Simplifying to the equivalent center point O requires multiplying by a transformation matrix. This matrix represents the m sets of unit forces and torques applied.
[0081] The simplified expression for the known 6-component force / moment F at the equivalent center point O is: (2) Similarly, we can conclude that: (3) Substituting equation (2) into equation (1), we get: (4) Multiply both sides of equation (4) by the matrix on the right. The conjugate transpose matrix We can obtain: (5) because Given a full-rank matrix, multiplying both sides of equation (5) by its inverse matrix on the right yields: (6) in, The calibration matrix for the test platform; matrix and Given a matrix; matrix This can be obtained through testing using a data acquisition system.
[0082] The calibration matrix for each frequency can be obtained using the above calibration method. , Choose 6, 9, 12, 15, ..., 48.
[0083] Subsequently, data from n verification points were used for verification, the relative error between the measured value and the applied value was calculated, and the calibration matrix with the smallest relative error was found. .
[0084] Calculation of measured values: using Channel voltage and Multiplication, that is .
[0085] Value calculation: using the transformation matrix of the verification point. Unidirectional known force applied to the verification point Multiplication, that is .
[0086] This leads to the formula for relative error:
[0087] Furthermore, the grouping of signal channels (at least 6 channels per group) includes direct grouping and grouping after parallel connection of force ring signal channels on the same inclined plane.
[0088] In the direct grouping method, 16 force measuring rings and 48 signal channels are used. The channels of the force measuring rings can be freely selected and combined, with multiple channel number options (6, 9, 12, ..., 48). Furthermore, depending on the different spatial positions of the force measuring rings, each channel number option has multiple combination methods.
[0089] In the method of grouping force-measuring ring signal channels after parallel connection on the same inclined plane, the three-directional signal channels of two force-measuring rings on the same inclined plane are connected in parallel using a tee, that is, two force-measuring rings on the same inclined plane are combined into one force-measuring ring group. At this time, the force-measuring platform has a total of 8 force-measuring ring groups and 24 signal channels. The force-measuring ring groups are connected to charge amplifiers, and the channels of the force-measuring ring groups can be freely selected for combination, with multiple channel number options (6, 9, 12, ..., 24). Furthermore, depending on the different spatial positions of the force-measuring ring groups, each channel number selection has multiple combination methods.
[0090] Setting too many force-measuring loops will reduce the force component that each loop can withstand, and result in an excessively high signal-to-noise ratio for the voltage signal output by the force-measuring loops. This application connects the force-measuring loops in parallel to improve the sensitivity and signal-to-noise ratio of each channel, thereby improving the accuracy of the six-component force analysis.
[0091] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.
[0092] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.
[0093] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.
[0094] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.
[0095] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0096] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.
[0097] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.
[0098] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.
[0099] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.
[0100] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0101] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.
Claims
1. A six-component force analytical method for a frustum-shaped force measuring table, characterized in that, The method includes the following steps: Several signal channel combinations are obtained, and the signal channel combinations are calibrated to determine the calibration matrix corresponding to each signal channel combination; the signal channel combinations are obtained by grouping the signal channels of the force measuring table. Select the signal channel combination with normal signal channels, and obtain the response signal matrix and the calibration matrix; The six-component forces are determined based on the response signal matrix and the calibration matrix.
2. The method as described in claim 1, characterized in that, The calibration of the plurality of signal channel combinations to determine the calibration matrix corresponding to each signal channel combination specifically includes: A standard load is applied to several calibration points of the force measuring table to obtain the excitation signal matrix of the calibration points and the response signal matrix of each signal channel combination. The excitation signal matrix is transformed based on the spatial transformation relationship of the calibration points to obtain the true force components; Matrix transformation is performed on each of the response signal matrices based on the actual force components to obtain calibration matrices corresponding to several signal channel combinations.
3. The method as described in claim 2, characterized in that, The step of calibrating the plurality of signal channel combinations to determine the calibration matrix corresponding to each signal channel combination further includes: The response signal phase is determined based on the response signal matrix, and the excitation signal phase of each calibration point is determined based on the excitation signal matrix. The phase difference between each calibration point is determined based on the phase of the response signal and the phase of the excitation signal. It is then determined whether the phase difference is within a preset range. If yes, the calibration point is determined as a qualified calibration point; otherwise, the calibration point is determined as an abnormal calibration point. The signal data of the abnormal calibration points are removed.
4. The method as described in claim 2, characterized in that, The calibration points include verification points; the step of performing matrix conversion on each of the response signal matrices based on the true force components to obtain calibration matrices corresponding to several signal channel combinations further includes: verifying the calibration matrices, specifically including: The measured value is determined based on the response signal matrix and the calibration matrix; The actual value is determined based on the excitation signal matrix of the verification point; Based on the relative error between the measured value and the actual value, the matrix with the smallest relative error is selected as the optimal calibration matrix.
5. The method as described in claim 2, characterized in that, The process of transforming the excitation signal matrix based on the spatial transformation relationship of the calibration points to obtain the true force components specifically includes: A spatial coordinate system is constructed with the center point of the force measuring platform, and the spatial force system transformation matrix is determined according to the spatial coordinates of the calibration point in the spatial coordinate system. The force component of the marker point is determined based on the excitation signal matrix of the calibrated point. The actual force components are calculated based on the force components at the identified points and the spatial force system transformation matrix.
6. The method as described in claim 2, characterized in that, Applying standard loads to several calibration points of the force measuring table specifically includes: Using signals of sinusoidal functions of multiple different frequencies as input, the exciter is driven to generate the standard load of multiple frequencies perpendicular to the plane where the calibration point is located.
7. A six-component force analysis system for a frustum-shaped force measuring stage, characterized in that, The system includes: The acquisition module is used to acquire the response signal output by the force measuring table and the excitation signal of the calibration point on the force measuring table; The excitation module is used to apply a standard load to the calibration point. A parsing module is used to execute the method described in any one of claims 1 to 6.
8. The system as described in claim 7, characterized in that, The excitation module includes: A vibrator is used to apply a standard load to the calibration point. A drive circuit is used to drive the exciter according to the signal input.
9. A six-component force analysis system for a frustum-shaped force measuring stage, characterized in that, The system includes a processor and a memory, the memory storing executable code that, when executed by the processor, implements the method according to any one of claims 1 to 6.
10. A computer program product, characterized in that, Includes a computer program that, when executed by a processor, implements the method of any one of claims 1 to 6.