Mass center measuring device and measuring method

Abstract

The invention relates to a mass center measuring device and a mass center measuring method. The device comprises a base, a plurality of weighing sensors, an adjustable platform, a motor, an articulated arm measurer and a data acquisition processor. The weighing sensor is fixed on the base and synchronously outputs vertical acting force of a measured object, the adjustable platform bears the measured object, the motor drives the measured object to rotate and change postures, the articulated arm measurer measures the postures of the measured object, and the data acquisition processor acquires force values and posture information under at least two postures. And three-dimensional centroid coordinates (X, Y, Z) of the measured object are calculated based on static balance. According to the device, three-dimensional measurement is realized through single-time clamping, repeated positioning errors are avoided, and efficiency and precision are improved; a weighing sensor and a simple structure are adopted, so that the cost is reduced; the whole process is automatic, human interference is reduced, and results are reliable. The method is suitable for the fields of weapons, aviation and the like and meets efficient and accurate mass center measurement requirements.

Description

Technical Field

[0001] This application belongs to the field of mechanical engineering and precision measurement technology, and specifically relates to a centroid measuring device and measuring method. Background Technology

[0002] In equipment applications requiring precise attitude and trajectory control, accurate mass measurement and precise characterization of the center of mass are of critical engineering significance. Center of mass measurement equipment, as a core tool supporting these needs, is widely used in important sectors of the national economy such as weaponry, aerospace, communication equipment, and automobile manufacturing. Its technological level and quantity directly affect the R&D efficiency and performance indicators of related products. In engineering practice, many pieces of equipment under test consist of cylindrical multi-section combinations, each requiring independent and accurate measurement of its mass and center of mass. This places higher demands on the versatility, measurement efficiency, and automation level of center of mass measurement equipment. However, current mainstream center of mass measurement equipment is mostly designed for specific applications, with generally low levels of automation, making it difficult to meet the high-efficiency and universal measurement needs arising from the rapid development of high-end equipment technology in my country, which has led to an increase in the weight and number of equipment types.

[0003] In existing technologies, methods for measuring the center of mass mainly include multi-point weighing, unbalanced torque method, multi-line pendulum method, and suspension method. Among these, multi-point weighing has become the mainstream technology for mass and center of mass measurement due to its simple measuring equipment structure, stable accuracy, high safety, and ability to simultaneously acquire mass and center of mass parameters. This method is based on the working mode of a measuring platform supported by multiple weighing sensors, and uses the principle of static torque balance to calculate the projected coordinates of the center of mass of the measured object in the coordinate system of the measuring platform. By rotating or tilting the measured object to another posture and repeating the measurement, the transformation relationship between the coordinate systems of the measuring platform and the measured object in the two measurements is combined to finally calculate the coordinates of the center of mass in the coordinate system of the measured object. However, this method relies on a mechanical positioning mechanism to determine the relative position of the object and the equipment, which is prone to introducing significant positioning errors and affecting the accuracy of the measurement.

[0004] Furthermore, in fields sensitive to center-of-gravity accuracy, such as aerospace, automotive manufacturing, weaponry, and precision instruments, deviations in the center-of-gravity of components or the entire machine directly determine the product's dynamic stability, operational reliability, and operational safety. Current mainstream center-of-gravity measurement methods are mostly limited to two-dimensional planar measurements—typically, the three-point support method can only obtain the horizontal coordinates (X, Y) of the center-of-gravity, while the height coordinate (Z) needs to be measured indirectly through workpiece flipping. These methods suffer from inefficiency due to multiple clamping operations, and the cumulative error between measurements at different orientations is easily amplified, making it difficult to meet high-precision measurement requirements. Although three-dimensional center-of-gravity measurement equipment has emerged, it often faces technical bottlenecks such as complex structure, high manufacturing costs, or stringent requirements for sensor calibration accuracy and data processing algorithms, making rapid deployment and convenient application in industrial settings difficult.

[0005] Although some centroid measurement devices and technologies have been developed, such as patent application "Centroid Measurement Device and System" (CN 114777998 A), utility model patent "Centroid Measurement Device" (CN 222719091U), patent application "A Centroid Measurement Method" (CN 104458124 A), patent application "A Centroid Measurement Equipment" (CN104458125 A), and patent application "A Centroid Measurement Instrument" (CN 110132489 A), these technologies and devices still have certain shortcomings in terms of versatility, operational efficiency, measurement accuracy, and engineering applicability, and cannot well meet the actual application needs.

[0006] In summary, given the shortcomings of existing centroid measurement technologies in terms of versatility, efficiency, accuracy, and engineering applicability, there is an urgent need to develop a new centroid measurement device that is relatively simple in structure, has high measurement accuracy, is easy to operate, and can complete three-dimensional centroid coordinate measurement in one go. This would break through the limitations of traditional methods and support the intelligent and efficient needs of high-end equipment research and development and production. Summary of the Invention

[0007] To address the aforementioned problems in the existing technology, this application proposes a new three-dimensional centroid measuring device and corresponding measuring method suitable for columnar parts, characterized by high integration, convenient measurement, and high measurement accuracy.

[0008] This application aims to improve measurement accuracy and operational efficiency. It applies non-contact measurement as an auxiliary method in the field of mass characteristic measurement. Through research on generalized platform design technology and high-precision measurement and processing technology, a universal device capable of integrated measurement of mass and centroid characteristic parameters has been developed. This device does not have strict requirements on the placement position and angle of the measured part, effectively avoiding the influence of positioning errors on the measurement results, resulting in high operational efficiency and measurement accuracy.

[0009] To achieve the above objectives, this application provides the following technical solution: The first aspect of this application provides a centroid measuring device, comprising: Base 1; At least three weighing sensors 2 fixed to the base 1 are used to synchronously output the reaction forces at each support point applied by the object under test 5; An adjustable platform 3 is positioned above the weighing sensor 2 to support the object being measured 5; The motor 4, which is electrically connected to the electric roller of the adjustable platform 3, is used to precisely control the rotation angle of the object being measured 5. The articulated arm measuring device 6, which is set above the adjustable platform 3, is used to accurately measure the measurement posture of the object 5. The data acquisition processor 7, which is connected to all the weighing sensors 2 and the articulated arm measuring device 6, is used to acquire real-time data from the weighing sensors 2 and the articulated arm measuring device 6, and calculate the three-dimensional centroid coordinates (X, Y, Z) of the object under test 5 based on the readings of each weighing sensor under at least two different poses, according to the built-in algorithm program.

[0010] Furthermore, in the device of this application, there are four weighing sensors 2 arranged in a rectangular shape; the adjustable platform 3 is floatingly supported above the four weighing sensors 2 by ball joints or flexible couplings to form a statically fixed four-point support structure.

[0011] Furthermore, the device of this application also includes a level or tilt sensor disposed above the base 1 for adjusting the height of the base 1 so that each weighing sensor 2 is always at the same horizontal plane.

[0012] Furthermore, in the device of this application, the operation process of the data acquisition processor 7 includes: (1) Collect the output values ​​of each weighing sensor 2 under at least two different poses; (2) Based on the principle of static equilibrium, establish a set of equations for the equilibrium of forces and moments; (3) Solve for the three-dimensional centroid coordinates of the measured object 5 in the measurement coordinate system. ; (4) Perform coordinate transformation to obtain the three-dimensional centroid coordinates in the product coordinate system. .

[0013] Furthermore, the operation process of the device in this application includes: The object to be tested 5 is fixed on the adjustable platform 3; In the initial pose, the total mass W of the measured object 5, W = F1a + F2a + F3a + F4a, and the projected coordinates of the center of mass in the horizontal plane are calculated from the readings F1a, F2a, F3a, and F4a of the four weighing sensors 2. ; Adjust the object to be measured 5 to an arbitrary tilt angle θ, and read the readings of each weighing sensor 2 again; The weight of the object being measured, 5, generates a new component force on the coordinate axis of the weighing sensor 2. By establishing a new torque balance equation and combining it with the data from the first measurement, the center of mass is calculated. coordinate.

[0014] Furthermore, in the device of this application, the algorithm program built into the data acquisition processor 7 is used to execute: In the first posture, the total mass of the object being measured is calculated based on the readings of each weighing sensor 2 as W = ΣFia, where Fia is the reading of each weighing sensor 2; Based on the torque balance equations: Σ(Fia·xi)=W·Xi, where xi is the distance from each weighing sensor to the X-axis of the measurement coordinate system; Σ(Fia·yi)=W·Yi, where yi is the distance from each weighing sensor to the Y-axis of the measurement coordinate system; Find the horizontal projection coordinates (Xi, Yi) of the centroid in the measurement coordinate system. Under the second attitude, obtain the new weighing sensor 2 reading Fi b and the corresponding attitude angle θ; Establish the spatial torque equilibrium equation: Σ(Fib·rib) = W·rc, where rib is the lever arm vector of the weighing sensor in the second posture, and rc is the radius vector of the centroid to be determined; Based on the pose changes during the two measurements and their relationship with the measurement coordinate system, the centroid height Z is calculated, and the three-dimensional centroid coordinates are finally output. .

[0015] Based on the relationship between the pose of the object under test 5 and the measurement coordinate system, the three-dimensional centroid coordinates in the measurement coordinate system are... Convert to 3D centroid coordinates in the product coordinate system .

[0016] A second aspect of this application provides a centroid measurement system, comprising: The lifting support module includes a base for supporting the entire center of mass measuring device; The weighing module includes four load cells, which are fixed to the base in a rectangular arrangement to synchronously measure the vertical force applied by the object being measured. The posture adjustment module includes an adjustable platform located above the weighing module for supporting the object to be measured. The adjustable platform drives the object to be measured to rotate via an electric roller to adjust the measurement posture. The data acquisition and processing system includes an articulated arm measuring device for acquiring the current posture of the object under test. The data acquisition and processing system is connected to all weighing sensor signals to acquire real-time data from each weighing sensor and calculates the three-dimensional centroid coordinates (X, Y, Z) of the object under test based on the readings of each weighing sensor under at least two different postures, according to the built-in algorithm program.

[0017] Furthermore, in the system of this application, the algorithm program built into the data acquisition and processing system is based on the principle of static equilibrium. By establishing a set of force and torque balance equations under different poses, the position of the center of mass relative to the measurement coordinate system is solved.

[0018] A third aspect of this application provides a method for measuring the centroid, the method being implemented using the aforementioned apparatus or system, comprising the following steps: S1. Initialization: Reset the adjustable platform 3 to the reference attitude and clear the balance sensor 2 to zero. S2, First posture measurement: Place the object to be measured 5 on the adjustable platform 3, and collect the output values ​​of each weighing sensor 2 and the first posture data output by the articulated arm measuring device 6; S3. Change posture: Motor 4 drives the electric roller on the adjustable platform 3 to rotate the object under test 5 around at least one axis by a set angle and lock it to obtain the second posture. S4. Second posture measurement: Collect the output values ​​of each weighing sensor 2 and the second posture data output by the articulated arm measuring device 6; S5. Data Processing: Based on the two output values ​​and attitude data, the data acquisition processor 7 establishes a set of static equilibrium equations and solves for the three-dimensional centroid coordinates (X, Y, Z) of the measured object 5. S6. Output results: Output the three-dimensional centroid coordinates and the total mass W of the measured object 5.

[0019] Furthermore, in the method of this application, the set of static equilibrium equations in step S5 includes: Total mass equation: W = ΣFi; In the formula, Fi is the output value of the i-th weighing sensor; Torque balance equation: Σ(Fi·ri) = W·rc; In the formula, ri is the spatial radius vector of the i-th weighing sensor support point in the corresponding posture, and rc is the radius vector of the measured material center in the measurement coordinate system. By simultaneously solving the equations under the two postures, and based on the pose transformation during the two measurements and the relationship with the measurement coordinate system, the least squares method or analytical method is used to solve for rc, thus obtaining the three-dimensional centroid coordinates (X, Y, Z) of the measured object 5. In summary, compared with existing technologies, this invention, through innovative structural design and system integration, achieves the following significant advantages in terms of centroid measurement efficiency, cost control, and automation level: (1) Achieving precise three-dimensional measurement with a single clamping, improving efficiency and accuracy: Traditional centroid measurement often relies on multiple clamping (such as flipping the workpiece) to obtain coordinates in different dimensions, which is prone to cumulative errors due to repeated positioning and is inefficient. This invention optimizes the measurement architecture and supports the in-situ determination of the three-dimensional centroid coordinates simultaneously after the measured object is fixed once, completely eliminating the positioning deviation introduced by repeated clamping, which not only shortens the measurement cycle, but also improves the overall measurement accuracy of the centroid coordinates to a higher level.

[0020] (2) Compact structure, controllable cost, and enhanced engineering applicability: This device adopts a modular integrated design, based on a weighing sensor array and a simple posture adjustment mechanism, to build a system architecture with three-dimensional measurement capabilities. Compared with similar high-precision measuring equipment, it avoids complex customized mechanical structure design and high-cost special component selection. While ensuring the integrity of the measurement function, it significantly reduces hardware manufacturing costs and maintenance complexity, making it more suitable for large-scale application needs in industrial sites.

[0021] (3) Full-process automation reduces human error interference: This device integrates a fully automatic data acquisition and processing module, which can acquire multi-sensor signals in real time and complete the calculation, verification and output of centroid coordinates based on preset algorithms. No manual intervention is required to adjust measurement parameters or manually process data throughout the process, avoiding the subjectivity and inconsistency of human operation in traditional methods. The stability, repeatability and reliability of measurement results are substantially improved.

[0022] In summary, this invention, through the synergistic innovation of "single-clamp multi-dimensional measurement," "low-cost compact structure," and "high level of automation," effectively overcomes the technical bottlenecks of low measurement efficiency, high cost, and human error interference in existing technologies, providing a better engineering solution for the measurement of the center of mass of high-end equipment.

[0023] Other features and advantages of this application will be set forth in detail in the following description, or will become apparent through the implementation of the relevant technical solutions of this application. The objectives and other advantages of this application can be achieved through the technical features and means explicitly pointed out in the description, claims, and drawings, and will be obtained through the implementation of these technical contents. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings involved in the description of the embodiments will be briefly introduced below. It should be noted that the accompanying drawings only show some embodiments of this application. For those skilled in the art, other related drawings can be derived from these drawings without creative effort.

[0025] Figure 1 A three-dimensional schematic diagram of the overall structure of the three-dimensional centroid measurement device provided in this application.

[0026] Figure 2 This is a schematic diagram illustrating the working principle of the device in the first orientation.

[0027] Figure 3 This is a schematic diagram illustrating the working principle of the device in the second pose.

[0028] Figure caption: 1-Base; 2-Weighing sensor; 3-Adjustable platform; 4-Motor; 5-Object under test; 6-Articulated arm measuring device; 7-Data acquisition processor. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be noted that the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0030] In this document, the term "comprising" and any variations thereof (such as "including," "including," etc.) are open-ended expressions and should be understood as "including but not limited to," meaning that the listed content is not exhaustive and may include other content not explicitly mentioned. The term "based on" should be understood as "at least partially based on," meaning that the basis or condition referred to may not be the only factor and may involve other relevant factors. The term "one embodiment" should be understood as "at least one embodiment," meaning that the described embodiment is not the only possible implementation, and other similar embodiments may exist.

[0031] In this application, the terms "a" and "a plurality of" are used to modify related elements or features, and their expression is illustrative rather than restrictive. Unless otherwise expressly stated in the context, "a" should be understood as "at least one," and "a plurality of" should be understood as "at least two." Those skilled in the art should reasonably interpret these terms based on the semantic and logical relationships of the context to ensure that they cover the possibility of "one or more."

[0032] Example: A high-precision three-dimensional centroid measurement device This device includes: a lifting support module, a weighing module, a posture adjustment module, and a data acquisition and processing system, wherein: The lifting support module serves as the support structure for the entire device.

[0033] The weighing module includes four high-precision load cells, which are fixed to the base in a rectangular arrangement to synchronously measure the vertical force applied to the object being measured.

[0034] The posture adjustment module includes an adjustable platform located above the weighing module, used to support the object being measured. This platform can rotate the object via an electric roller to adjust the measurement posture.

[0035] The data acquisition and processing system includes an articulated arm measuring device for acquiring the current posture of the object under test. The system is connected to all weighing sensor signals to acquire real-time data from each weighing sensor and has a built-in algorithm program to calculate the three-dimensional centroid coordinates (X, Y, Z) of the object under test based on the readings of each weighing sensor under at least two different postures.

[0036] In addition, the device may include a level or tilt sensor for adjusting the height of the base so that the four load cells of the weighing module are always on the same horizontal plane.

[0037] Furthermore, the calculation algorithm of the data acquisition and processing system is based on the principle of static equilibrium. By establishing a set of force and torque balance equations under different poses, the position of the center of mass relative to the measurement coordinate system is solved.

[0038] The working principle of this device is as follows: The object to be measured is fixed on an adjustable platform. First, in the initial position, the total mass W = F1a + F2a + F3a + F4a, and the projected coordinates (X, Y) of the center of mass in the horizontal plane are calculated from the readings F1a, F2a, F3a, and F4a of the four weighing sensors. Then, the object is adjusted to an arbitrary tilt angle θ, and the readings of each weighing sensor are read again. At this time, the gravity of the object generates new components of force on the coordinate axes of the weighing sensors. By establishing a new torque balance equation and combining it with the data from the first measurement, the Z-coordinate of the center of mass can be calculated.

[0039] To more clearly illustrate the technical solution of this application, the following will provide further explanation through specific scenario embodiments.

[0040] Figure 1 The overall structural perspective diagram of the three-dimensional centroid measuring device provided in this application is shown in the figure. This embodiment of the high-precision three-dimensional centroid measuring device includes a robust base 1. Four high-precision digital load cells 2 are rectangularly distributed and mounted on the base 1. A square adjustable platform 3 is mounted on the top measuring platform of the four load cells 2 via a coupling device. The electric roller (clamping roller) of the adjustable platform 3 is connected to a motor 4, which can precisely control the rotation angle of the object being measured 5. An articulated arm measuring device 6 can accurately measure the measurement posture of the object being measured. All four load cells 2 and the articulated arm measuring device 6 are connected to a data acquisition processor 7 via data cables.

[0041] Measurement process: 1. Initialization: The adjustable platform 3 is in a horizontal position, and the data acquisition processor 7 performs zeroing and calibration on each weighing sensor 2.

[0042] 2. First measurement (e.g.) Figure 2As shown): The object to be measured 5 is placed on the adjustable platform 3. The data acquisition processor 7 acquires and records the readings F1a, F2a, F3a, and F4a of the four weighing sensors 2 at this time, and the articulated arm measuring device 6 measures the current pose of the object to be measured 5.

[0043] 3. Change position: Control motor 4 to rotate the object under test 5 by a certain angle to keep it stable.

[0044] 4. Second measurement (e.g.) Figure 3 As shown): The data acquisition processor 7 acquires and records the readings F1b, F2b, F3b, and F4b of the four weighing sensors 2 in the new pose, and the articulated arm measuring device 6 measures the current pose of the object 5.

[0045] 5. Data Processing: The built-in algorithm program of the data acquisition processor 7 performs the following calculations: Calculate the total mass: W = F1a + F2a + F3a + F4a Calculate the centroid projection coordinates X and Y based on the initial pose data (based on the torque balance equation).

[0046] Establish a mechanical model under tilted orientation. Decompose the gravity W into two components: one perpendicular to the platform and one parallel to the platform. The component parallel to the platform generates an additional torque, which is reflected by the changes in the readings of the three sensors. Using the known tilt angle θ, sensor layout geometry, and the force values ​​measured twice, establish and solve an equation regarding the height of the center of mass Z.

[0047] 6. Output results: The total mass W and three-dimensional centroid coordinates (X, Y, Z) of the measured object 5 are output on the display screen of the data acquisition processor 7.

[0048] While the foregoing discussion contains several specific implementation details, these details should not be construed as limiting the scope of this application. The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of this application is not limited to technical solutions formed by specific combinations of the above-described technical features. Furthermore, this application should also cover other technical solutions formed by any combination of the above-described technical features or their equivalents without departing from the foregoing disclosed concept.

[0049] Those skilled in the art should also understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features, without departing from the spirit and scope of the technical solutions of the embodiments of this application. These modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the core spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A centroid measuring device, characterized in that, The device includes: Base (1); At least three weighing sensors (2) fixed to the base (1) are used to synchronously output the reaction forces at each support point applied by the object under test (5); An adjustable platform (3) is located above the weighing sensor (2) and is used to support the object to be measured (5). The motor (4) is electrically connected to the electric roller of the adjustable platform (3) and is used to precisely control the rotation angle of the object being measured (5); The articulated arm measuring device (6) is set above the adjustable platform (3) for accurately measuring the measurement pose of the object (5); The data acquisition processor (7) is connected to all the weighing sensors (2) and articulated arm measuring device (6) to acquire real-time data from the weighing sensors (2) and articulated arm measuring device (6), and calculates the three-dimensional centroid coordinates (X, Y, Z) of the object under test (5) based on the readings of each weighing sensor under at least two different poses according to the built-in algorithm program.

2. The apparatus according to claim 1, characterized in that, There are four weighing sensors (2) arranged in a rectangular shape; the adjustable platform (3) is floatingly supported above the four weighing sensors (2) by ball joints or flexible couplings to form a statically fixed four-point support structure.

3. The apparatus according to claim 1, characterized in that, The device also includes a level or tilt sensor disposed above the base (1) for adjusting the height of the base (1) so that each weighing sensor (2) is always on the same horizontal plane.

4. The apparatus according to claim 1, characterized in that, The working process of the data acquisition processor (7) includes: (1) Collect the output values ​​of each weighing sensor (2) under at least two different poses; (2) Based on the principle of static equilibrium, establish a set of equations for the equilibrium of forces and moments; (3) Solve for the three-dimensional centroid coordinates (X, Y, Z) of the object under test in the measurement coordinate system.

5. The apparatus according to claim 1, characterized in that, The operation process of the device includes: The object to be tested (5) is fixed on the adjustable platform (3); In the initial pose, the total mass W = F1a + F2a + F3a + F4a of the object being measured (5) and the projected coordinates (X, Y) of the center of mass in the horizontal plane are calculated by using the readings F1a, F2a, F3a and F4a of the four weighing sensors (2). Adjust the object to be measured (5) to an arbitrary tilt angle θ, and read the readings of each weighing sensor (2) again; The weight of the object being measured (5) generates a new component force on the coordinate axis of the weighing sensor (2). By establishing a new torque balance equation and combining the data from the first measurement, the Z coordinate of the center of mass is calculated.

6. The apparatus according to claim 1, characterized in that, The algorithm program built into the data acquisition processor (7) is used to execute: In the first posture, the total mass of the object being measured is calculated as W = ΣFia based on the readings of each weighing sensor (2), where Fia is the reading of each weighing sensor (2); Based on the torque balance equations: Σ(Fia·xi)=W·Xi, where xi is the distance from each weighing sensor to the X-axis of the measurement coordinate system; Σ(Fia·yi)=W·Yi, where yi is the distance from each weighing sensor to the Y-axis of the measurement coordinate system; Find the horizontal projection coordinates (Xi, Yi) of the centroid in the measurement coordinate system. Under the second attitude, the new weighing sensor (2) reading Fi b and the corresponding attitude angle θ are obtained; Establish the spatial torque equilibrium equation: Σ(Fib·rib) = W·rc, where rib is the lever arm vector of the weighing sensor in the second posture, and rc is the radius vector of the centroid to be determined; Based on the pose changes during the two measurements and the relationship with the measurement coordinate system, the centroid height Z is calculated, and the three-dimensional centroid coordinates (X, Y, Z) are finally output.

7. A centroid measurement system, characterized in that, The system includes: The lifting support module includes a base for supporting the entire center of mass measuring device; The weighing module includes four load cells, which are fixed to the base in a rectangular arrangement to synchronously measure the vertical force applied by the object being measured. The posture adjustment module includes an adjustable platform located above the weighing module for supporting the object to be measured. The adjustable platform drives the object to be measured to rotate via an electric roller to adjust the measurement posture. The data acquisition and processing system includes an articulated arm measuring device for acquiring the current posture of the object under test. The data acquisition and processing system is connected to all weighing sensor signals to acquire real-time data from each weighing sensor and calculates the three-dimensional centroid coordinates (X, Y, Z) of the object under test based on the readings of each weighing sensor under at least two different postures, according to the built-in algorithm program.

8. The system according to claim 7, characterized in that, The built-in algorithm of the data acquisition and processing system is based on the principle of static equilibrium. By establishing a set of force and torque balance equations under different poses, the position of the center of mass relative to the measurement coordinate system is solved.

9. A method for measuring the centroid, characterized in that, The method is implemented using the apparatus according to any one of claims 1-6, and includes the following steps: S1. Initialization: Reset the adjustable platform (3) to the reference attitude and clear the gravity sensor (2); S2, First posture measurement: Place the object to be measured (5) on the adjustable platform (3), and collect the output values ​​of each weighing sensor (2) and the first posture data output by the articulated arm measuring device (6); S3. Change posture: The motor (4) drives the electric roller on the adjustable platform (3) to rotate the object (5) around at least one axis by a set angle and lock it to obtain the second posture; S4. Second posture measurement: Collect the output values ​​of each weighing sensor (2) and the second posture data output by the articulated arm measuring device (6); S5. Data processing: The data acquisition processor (7) establishes a set of static equilibrium equations based on the two output values ​​and attitude data and solves the three-dimensional centroid coordinates (X, Y, Z) of the measured object (5). S6. Output results: Output the three-dimensional centroid coordinates and the total mass W of the measured object (5).

10. The method according to claim 9, characterized in that, The set of static equilibrium equations mentioned in step S5 includes: Total mass equation: W = ΣFi; In the formula, Fi is the output value of the i-th weighing sensor; Torque balance equation: Σ(Fi·ri) = W·rc; In the formula, ri is the spatial radius vector of the i-th weighing sensor support point in the corresponding posture, and rc is the radius vector of the measured material center in the measurement coordinate system. Based on the pose transformation during the two measurements and the relationship with the measurement coordinate system, the least squares method or analytical method is used to solve rc, and the three-dimensional centroid coordinates (X, Y, Z) of the measured object (5) are obtained.

Images