Digital accelerometer calibration tool
By designing digital accelerometer calibration tooling, simulating the rope vibration frequency and direction, and using actual measured data optimization algorithms, the problem of dependence on high-cost and high-precision external equipment in the existing technology is solved, and efficient and low-cost calibration effect is achieved.
Patent Information
- Application Number
- CN202422090085.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-27
- Publication Date
- 2025-08-22
- Estimated Expiration
- 2034-08-27
AI Technical Summary
In the prior art, the calibration of digital accelerometers relies on high-precision external equipment, which is costly and complex, making it difficult to meet the needs of large-scale installations in the railway and power industries.
Design a digital accelerometer calibration tool, including a rack, motor, crank rod, connecting rod, slider table and PCB board, and simulate the vibration frequency and direction of ropes, and use the measured data optimization algorithm to calibrate, reducing costs and improving accuracy.
It realizes efficient calibration of digital accelerometers in a simulated and real-life use environment, reduces costs, improves calibration accuracy and reliability, and can promptly detect safety hazards of cable and rope damage.
Smart Images
Figure CN223259750U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of testing, in particular to a digital accelerometer calibration tool. Background Art
[0002] With the increasing development of science and technology, the service life of ropes, contact cables, and power transmission cables in harsh environments in the fields of rail transportation and power transmission has become a safety hazard, which is crucial for ensuring the safe operation of trains and the safe transmission of electricity. Damage to cables and ropes generally occurs when their vibration amplitude exceeds the tension allowed by their design, causing them to break or their cross-section to be sharply reduced and unable to carry current. Railway transportation spans a vast area. In remote, unmanned sections of the line, the vibration amplitude of the contact wire increases dramatically when trains pass at high speeds. The vibration amplitude of the contact wire increases even more in windy mountain passes. In such environments, cables and ropes are prone to damage, leading to safety accidents. Therefore, it is necessary to monitor the vibration amplitude of these cables and ropes.
[0003] After cables and ropes are installed and fixed during use, their vibration amplitude generally has two states: one horizontal and one vertical. Vibration-related physical quantities include acceleration, velocity, and displacement. Measuring acceleration signals is convenient and economical, and is often used to measure vibration in engineering. Digital accelerometer sensors are used to measure acceleration in spatial systems, that is, to measure the speed of an object's velocity change in space. When cables and ropes swing, a certain electrical signal is generated internally by the digital accelerometer. After data processing, the speed, displacement, and angle of the cable or rope's swing can be calculated and transmitted wirelessly to the data center to monitor whether the cable status is abnormal.
[0004] Digital accelerometers are part of a monitoring product family. During use, they require zero-point calibration to ensure uniformity, accuracy, and reliability within a system. High-precision calibration methods for digital accelerometers rely primarily on high-precision external equipment, such as marble platforms, turntables, and vibration tables. These require specialized instrumentation for calibration and testing, and zero-point calibration is typically charged on a per-use basis. These instruments are often expensive. The railway and power industries have extensive installation spans and a vast number of monitoring devices, necessitating significant costs for calibrating digital accelerometers. Furthermore, the vibration amplitude accuracy of cables and ropes is typically between 5mm and 10mm, making the use of high-precision instrumentation for zero-point calibration of these digital accelerometers prohibitive.
[0005] In summary, the accelerometer measurement and calibration in the prior art has the problems of reliance on high-precision external equipment, a complex calibration process, and high costs. Utility Model Content
[0006] In order to solve the problems existing in the prior art, the utility model provides a digital accelerometer calibration tool. The utility model has good operability for sensor calibration before using a digital accelerometer to measure acceleration signals, can reduce calibration costs, better simulate the actual usage environment, and use measured data to optimize the algorithm to obtain higher accuracy and reliability.
[0007] To achieve the above objectives, the present invention provides the following technical solutions:
[0008] A digital accelerometer calibration fixture includes a frame, a motor, a crank rod, a connecting rod, a slider table, a PCB board and a slide table;
[0009] The motor is fixed on the frame; the output shaft of the motor is connected to a crank rod; the crank rod is rotatably connected to one end of the connecting rod; the other end of the connecting rod is rotatably connected to the slider table, and the slider table is slidably connected along a slide set on the frame to form a crank slider mechanism; the slider table is used to fix a PCB board containing a digital accelerometer.
[0010] Preferably, the sampling frequency of the digital accelerometer is 100 Hz.
[0011] Preferably, the motor is a stepper motor.
[0012] Preferably, the bottom of the slide is marked with a range.
[0013] Preferably, the stroke of the slide is 800 mm.
[0014] Preferably, the length of the crank rod is smaller than the length of the connecting rod.
[0015] Preferably, the crank rod and one end of the connecting rod are rotationally connected via a rotating shaft.
[0016] Preferably, the slider platform and the slide platform are hinged.
[0017] Compared with the prior art, the present invention has the following beneficial technical effects:
[0018] The utility model provides a digital accelerometer calibration fixture. By adjusting the rotation speed of the stepper motor of the fixture, different vibration frequencies of the rope can be simulated. By adjusting the installation length of the crank and the connecting rod, the vibration swing in the horizontal and vertical directions can be simulated. Adding a range mark on the frame can facilitate reading different strokes under multiple vibration frequencies. The digital accelerometer is calibrated by comparing the measured data with the acceleration measured by the accelerometer. The digital accelerometer calibrated by this fixture can be used to measure the vibration swing of cables, ropes, etc., monitor their position changes, and promptly detect damage to cables and ropes in harsh environments or unmanned environments, thereby resolving safety hazards. This fixture has good operability for sensor calibration before using a digital accelerometer to measure acceleration signals, can reduce calibration costs, better simulate the actual use environment, and optimize algorithms using measured data to obtain higher accuracy and reliability. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is a schematic diagram of the horizontal installation of a digital accelerometer calibration tooling of the present invention;
[0020] Figure 2 This is a schematic diagram of the vertical installation of a digital accelerometer calibration tooling of the present utility model;
[0021] Figure 3 for Figure 1 The view of the local A in the middle;
[0022] In the accompanying drawings: 1 is a frame; 2 is a motor; 3 is a crank rod; 4 is a rotating shaft; 5 is a connecting rod; 6 is a slider table; 7 is a PCB board; and 8 is a slide table. DETAILED DESCRIPTION
[0023] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be regarded as illustrative in nature and not restrictive.
[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present invention.
[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined.
[0026] In this utility model, unless otherwise expressly specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.
[0027] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is lower in level than the second feature.
[0028] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.
[0029] It should also be understood that the terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in this specification and the appended claims, the singular forms "a", "an" and "the" are intended to include plural forms unless the context clearly indicates otherwise.
[0030] It should be further understood that the term “and / or” used in the present specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.
[0031] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments disclosed herein. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes, relative sizes, and positional relationships of the various regions and layers shown in the figures are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.
[0032] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.
[0033] Example
[0034] like Figure 1 As shown, a digital accelerometer calibration tool of the present invention mainly includes: a frame 1, a motor 2, a crank rod 3, a rotating shaft 4, a connecting rod 5, a slider table 6, a PCB board 7 and a slide table 8.
[0035] The motor 2 is fixed on the frame 1; the output shaft of the motor 2 is connected to the crank rod 3; the crank rod 3 is rotatably connected to one end of the connecting rod 5; the other end of the connecting rod 5 is rotatably connected to the slider table 6, and the slider table 6 is slidably connected along the slide 8 set on the frame 1 to form a crank slider mechanism; the slider table 6 is used to fix the PCB board 7 containing the digital accelerometer.
[0036] In such Figure 1 and Figure 2 In the illustrated device, the crank length is adjusted to 100 mm and the connecting rod length to 300 mm to meet the requirements for forming a slider-crank mechanism. An ADXL346 digital accelerometer is selected and fixed to the slider platform 6. The length of the slider platform 8 can be selected based on the actual travel, which is related to the length of the crank rod 3 and the connecting rod mechanism. The slider length can be longer. For example, in the example, the crank and connecting rod are 400 mm, and a slider platform 8 travel of 800 mm can achieve continuous sliding.
[0037] The sampling frequency of the digital accelerometer in this embodiment is 100 Hz. By controlling the different rotation speeds of the stepper motor, acceleration and displacement data at different frequencies in the horizontal and vertical directions are obtained.
[0038] This embodiment also includes a processor, which averages the sampling values of the digital accelerometer, obtains acceleration, velocity and displacement curves after calibration and filtering, and compares them with the actual motion displacement on the slider table 6 to calibrate and optimize the digital accelerometer.
[0039] In this embodiment, measured data and acceleration measured by an accelerometer are processed and fitted using a Freescale solution that uses a three-axis acceleration-based displacement algorithm to optimize the accelerometer's solution. The calibrated accelerometer is then mounted on a vibrating rope through a structural component. When the rope vibrates, the algorithm can determine positional information such as the rope's displacement and angular change.
[0040] The utility model can simulate different vibration frequencies of the rope by adjusting the rotation speed of the stepper motor of this fixture, and can simulate the vibration amplitude in the horizontal and vertical directions by adjusting the installation length of the crank and the connecting rod. Adding a range mark on the frame can facilitate reading different strokes under multiple vibration frequencies. The displacement is obtained by fitting the measured data and the acceleration measured by the accelerometer after data processing and algorithm optimization, thereby optimizing the accelerometer solution algorithm. The digital accelerometer calibrated by this fixture can be used to measure the vibration amplitude of cables, ropes, etc., monitor their position changes, and promptly detect damage to cables and ropes in harsh environments and unmanned environments, thereby resolving safety hazards. This fixture has good operability for sensor calibration before using a digital accelerometer to measure acceleration signals, can reduce calibration costs, better simulate the actual use environment, and optimize the algorithm using measured data to obtain higher accuracy and reliability.
[0041] This utility model utilizes a digital accelerometer calibration fixture. By replacing cranks and connecting rods of varying specifications as needed (to meet the requirements for forming a crank-slider mechanism), and by setting the stepper motor at varying speeds, it simulates displacement at different vibration frequencies. This provides an experimental basis for optimizing the zero-point calibration algorithm for digital accelerometers used to measure the vibration amplitude of cables and ropes. The displacement test mentioned in this utility model can also utilize machine vision and optical imaging methods to accurately measure displacement.
[0042] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended that all changes that fall within the meaning and range of equivalents of the claims are included in the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.
[0043] In addition, it should be understood that although this specification describes the embodiments, not every embodiment contains only one independent technical solution. This description is for clarity only. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for the purpose of illustrating the technical concept of the present utility model and cannot be used to limit the scope of protection of the present utility model. Any changes made based on the technical solution in accordance with the technical concept proposed by the present utility model shall fall within the scope of protection of the claims of the present utility model.
Claims
1. A digital accelerometer calibration tool, characterized in that: It includes a frame (1), a motor (2), a crank rod (3), a connecting rod (5), a slider table (6), a PCB board (7) and a slide table (8); The motor (2) is fixed on the frame (1); the output shaft of the motor (2) is connected to a crank rod (3); the crank rod (3) is rotatably connected to one end of a connecting rod (5); the other end of the connecting rod (5) is rotatably connected to a slider table (6), and the slider table (6) is slidably connected along a slide table (8) provided on the frame (1) to form a crank slider mechanism; a PCB board (7) containing a digital accelerometer is fixed on the slider table (6).
2. The digital accelerometer calibration tool according to claim 1, characterized in that: The sampling frequency of the digital accelerometer is 100 Hz.
3. The digital accelerometer calibration tool according to claim 1, characterized in that: The motor (2) is a stepping motor.
4. The digital accelerometer calibration tool according to claim 1, characterized in that: The bottom of the slide (8) is marked with a measuring range.
5. The digital accelerometer calibration tool according to claim 1, characterized in that: The travel of the slide (8) is 800 mm.
6. The digital accelerometer calibration tool according to claim 1, characterized in that: The length of the crank rod (3) is smaller than the length of the connecting rod (5).
7. The digital accelerometer calibration tool according to claim 1, characterized in that: The crank rod (3) and one end of the connecting rod (5) are rotationally connected via a rotating shaft (4).
8. The digital accelerometer calibration tool according to claim 1, characterized in that: The slider platform (6) and the slide platform (8) are hinged.