Electronic scale calibration method based on laser scanner

Abstract

The invention discloses an electronic scale calibration method based on a laser scanner. The method comprises the following steps: (1) obtaining the weighing platform height of an electronic scale to be calibrated through a laser matrix array; (2) a servo motor is adopted to drive a workbench bearing the electronic scale, so that the workbench can ascend or descend; (3) transferring a mechanical arm and controlling the mechanical arm to clamp a weight, recording a clamping point of the weight, placing the weight on a weighing platform of the electronic scale, and recording a placing point of the weight; and (4) obtaining the real-time weight of the electronic scale, the real-time weight being the display weight of the electronic scale, and comparing the real-time weight with the actual weight of the weight to obtain an error value. According to the electronic scale calibration method based on the laser scanner, through cooperative work of various automatic devices such as the laser matrix array, the mechanical arm and the servo motor, full-automatic execution of the electronic scale calibration process is achieved, manual intervention is greatly reduced, and calibration efficiency and consistency are improved.

Description

Technical Field

[0001] This invention relates to the field of electronic scale technology, and more specifically to an electronic scale calibration method based on a laser scanner. Background Technology

[0002] During the production of electronic scales, calibration and verification are required to ensure their weighing accuracy and reliability. The calibration process typically involves using standard weights to technically adjust the scale's measurement accuracy and correct its output signal to ensure that the displayed weight matches the actual weight of the weights.

[0003] Traditional electronic scale calibration methods mainly rely on manually placing standard weights and reading the weighing results for comparison and adjustment. While this method is simple and intuitive, the process of manually placing standard weights is time-consuming and labor-intensive. Furthermore, data collection, recording, and calculation in this way often depend on manual input, making it prone to operational errors or recording mistakes. In modern manufacturing, traditional calibration methods are no longer compatible with efficient and automated workflows. Summary of the Invention

[0004] To overcome the above shortcomings, the purpose of this invention is to provide an electronic scale calibration method based on a laser scanner. By working together with various automated devices such as laser matrix arrays, robotic arms, and servo motors, the calibration process of electronic scales can be fully automated, greatly reducing manual intervention and improving calibration efficiency and consistency.

[0005] Technical solution: This invention discloses a calibration method for electronic scales based on a laser scanner, comprising the following steps:

[0006] (1) The platform height of the electronic scale to be calibrated is obtained by using a laser matrix array, thereby constructing a three-axis positioning coordinate system;

[0007] (2) A servo motor is used to drive the worktable that carries the electronic scale, so that the worktable can rise or fall. Based on the measurement data provided by the laser matrix array, the height of the electronic scale platform is adjusted to the reference working surface.

[0008] (3) Mobilize the robotic arm and control it to grip the weight, while recording the gripping point of the weight, place the weight on the scale platform of the electronic scale, while recording the placement point of the weight, connect the positions of multiple gripping points and placement points to form a complete working path, and generate a repeatable loop command.

[0009] (4) Obtain the real-time weight of the electronic scale, which is the displayed weight of the electronic scale. Compare the real-time weight with the actual weight of the weight to obtain the error value, wherein the error value = (real-time weight - actual weight) / actual weight × 100%.

[0010] If the error value is less than 1%, the detection is considered normal; if the error value is greater than 1%, the detection is considered abnormal.

[0011] Furthermore, the laser matrix array includes at least three sets of laser scanners, the laser scanners having a frequency of 100Hz and an accuracy of 0.01mm.

[0012] Furthermore, step (3) also includes zeroing the electronic scale and obtaining the AD value of the electronic scale when it is empty; when the electronic scale is weighing, obtaining the AD value of the electronic scale and storing the AD value in the electronic scale and transmitting it to the database.

[0013] Furthermore, step (3) also includes switching between multiple weights, the weights including at least 6kg, 15kg and 30kg of different specifications.

[0014] Furthermore, step (4) also includes transmitting the detection results that are determined to be abnormal to the monitoring platform.

[0015] Furthermore, the height of the electronic scale platform ranges from 150 to 450 mm, and the height of the reference working surface is 800 mm.

[0016] Furthermore, step (3) also includes the following: after the robotic arm completes the placement of the weight, the laser scanner continues to perform laser scanning on the placement position of the weight to determine whether the placement position of the weight has shifted, and when the shift value is greater than a preset threshold, the robotic arm is controlled to replace the weight.

[0017] Furthermore, the method also includes generating a calibration report for the electronic scale after completing the calibration of the preset weight of the weight. The calibration report includes: the error value of each weight point, the number of placements, the AD value of the empty scale, the AD value of the weighed scale, and the judgment result of whether it is qualified.

[0018] The beneficial effects of this invention are as follows:

[0019] (1) The present invention sets up at least three sets of laser scanners to form a laser matrix array, which can acquire the three-dimensional coordinate information of the scale platform to be calibrated in real time, quickly establish a three-axis coordinate system, realize accurate measurement and feedback of the height of the scale platform, and automatically adjust the platform to the height of the reference working surface with the servo motor, so as to ensure that the scales of different specifications can be calibrated at the same height of the reference working surface, thereby improving the consistency of the calibration results.

[0020] (2) This invention achieves automatic clamping and precise placement of weights by using a robotic arm, and combines laser matrix array to assist in identifying and positioning the placement of weights. This enables full automation of the entire process from zeroing the electronic scale, clamping, placing, weighing, error judgment to data recording. It solves the problems of low efficiency, large error and inconsistency in the traditional manual placement of weights, greatly reduces the dependence on manual labor, and at the same time reduces labor costs and human error.

[0021] (3) When calibrating the electronic scale, the present invention uses a multi-segment switching method to clamp weights of different specifications for calibration testing, and the path planning connects multiple clamping points and placement points to form a repeatable multi-segment working path. The robotic arm automatically clamps weights of different weights according to the working path and executes the cyclic calibration command, thereby realizing rapid testing of multiple weight points. Attached Figure Description

[0022] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and are not intended to specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can select various possible shapes and proportions to implement the invention according to specific circumstances. In the drawings:

[0023] Figure 1 This is a flowchart of the electronic scale calibration method based on a laser scanner according to the present invention. Detailed Implementation

[0024] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

[0025] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The embodiments of this invention will now be described according to its overall structure.

[0026] like Figure 1 As shown, this invention discloses a calibration method for electronic scales based on a laser scanner, comprising the following steps:

[0027] (1) The platform height of the electronic scale to be calibrated is obtained by using a laser matrix array, thereby constructing a three-axis positioning coordinate system;

[0028] (2) A servo motor is used to drive the worktable that carries the electronic scale, so that the worktable can rise or fall. Based on the measurement data provided by the laser matrix array, the height of the electronic scale platform is adjusted to the reference working surface.

[0029] (3) Mobilize the robotic arm and control it to grip the weight, while recording the gripping point of the weight, place the weight on the scale platform of the electronic scale, while recording the placement point of the weight, connect the positions of multiple gripping points and placement points to form a complete working path, and generate a repeatable loop command.

[0030] (4) Obtain the real-time weight of the electronic scale, which is the displayed weight of the electronic scale. Compare the real-time weight with the actual weight of the weight to obtain the error value, wherein the error value = (real-time weight - actual weight) / actual weight × 100%.

[0031] If the error value is less than 1%, the detection is considered normal; if the error value is greater than 1%, the detection is considered abnormal.

[0032] Using the above method, this invention measures the height of the electronic scale platform in real time using a laser matrix array to obtain its three-dimensional position information and thereby construct a stable three-axis positioning coordinate system. Combined with a servo motor, the lifting state of the electronic scale's worktable is automatically adjusted according to the measured platform height, ensuring that the platform surface is aligned with a set reference working surface, thus providing a unified operating plane for subsequent electronic scale weighing calibration.

[0033] Based on this, the world coordinate system is transformed into the coordinate system of the robotic arm through a laser matrix array with known spatial positions. The robotic arm is then used to grip standard weights and accurately record key point information during the gripping and placement process. This generates a serial operation path that can be executed repeatedly, effectively achieving precise automatic placement of the weights. This not only ensures the repeatability and consistency of actions between each calibration point but also reduces errors that may be caused by human operation, such as the weights being placed off-center from the preset position.

[0034] In this invention, the laser array matrix provides non-contact measurement with extremely high spatial accuracy for electronic scale calibration, optimizing the traditional manual measurement method. On the other hand, this invention constructs an automatic and intelligent calibration system by means of automated operation of a robotic arm and real-time error judgment mechanism, which not only significantly improves calibration efficiency but also reduces labor costs.

[0035] Furthermore, the laser matrix array includes at least three sets of laser scanners, each with a scanning frequency of 100Hz and a scanning accuracy of 0.01mm. Preferably, the three sets of laser scanners scan the electronic scale to be calibrated from different directions to obtain the height and relative position information of the scale platform in space. Compared with the traditional single-point contact measurement method, the present invention uses a high-frequency, high-precision laser scanner, which not only improves the stability of the measurement results but also is applicable to electronic scales of different specifications. Based on the different platform heights of the electronic scales, the rising or falling height of the worktable controlled by the servo motor is automatically adjusted to ensure that the platform plane of any electronic scale is located on the reference working surface.

[0036] Preferably, step (3) further includes zeroing the electronic scale and collecting and storing the AD value, i.e., analog-to-digital conversion data. Specifically, before placing the weights, first ensure that the electronic scale is in an empty state and zeroed. In this state, acquire and record the AD value of the electronic scale when it is empty. Then, after the weights are placed and the electronic scale is in the weighing state, collect the AD value in the weighing state again. Store the AD values ​​in the above states in the internal storage module of the electronic scale, and simultaneously upload them to the database for archiving.

[0037] Preferably, step (3) further includes multiple weight switching. Specifically, the weights have various weight specifications, including but not limited to standard weights of 6kg, 15kg, and 30kg. The scale can be equipped with standard weights matching its capacity, and different weight specifications can be selected according to a preset calibration process to perform segmented, multi-weight-point automatic calibration. During the calibration operation, the robotic arm sequentially picks up weights of different weights according to task instructions and places them on the scale platform. After each placement, the starting and ending points of the placement action are automatically recorded, i.e., the picking point and the placement point. Then, weighing data is collected and the error value is judged, followed by switching to the next weight segment. The multi-segment weight switching calibration operation allows the scale to be calibrated at multiple weight points, thereby covering the entire or key range of the scale and improving the weighing accuracy.

[0038] Furthermore, step (4) also includes transmitting the detection results judged as abnormal to the monitoring platform. After the weights are placed and weighed, the real-time weight of the electronic scale is compared with the actual weight of the placed weights to calculate the error value, where the error value = (real-time weight - actual weight) / actual weight × 100%, and the electronic scale is judged to meet the standard based on whether the preset error threshold is less than 1%. When the calculation result shows that the error value exceeds the allowable range, it is judged as an abnormality, and the system automatically transmits the abnormality information to the monitoring platform. The uploaded detection content includes, but is not limited to: electronic scale number, weight specifications, weighing value, error value, etc.

[0039] Furthermore, due to design differences between various specifications of electronic scales, their platform heights vary. Therefore, calibration under these inconsistent height conditions is highly susceptible to operational errors caused by vertical height differences. This is especially true when the robotic arm is gripping and placing standard weights; the inconsistent height can affect the gripping path, placement angle, and landing point, thus impacting the reliability of the calibration results. The platform height of electronic scales typically ranges from 150mm to 450mm, with a reference working surface height of 800mm. The reference working surface is usually higher than the platform height. A servo motor controls the lifting and lowering of the platform to ensure that the platform and reference working surface are at the same height. This allows for consistent measurement and accurate comparisons of various models and specifications of electronic scales during calibration, ensuring the platform is uniformly positioned on the reference working surface.

[0040] Furthermore, in step (3), after the robotic arm completes the placement of the weight, the laser scanner in the laser matrix array continues to perform laser scanning on the placement position of the weight to confirm whether the weight is accurately placed on the designated position of the electronic scale platform. The scanning process of the laser scanner will obtain the actual placement position coordinates of the weight and compare them with the preset placement point to calculate the offset of the weight placement position. If the actual offset value is less than the preset deviation threshold, it is considered to be placed accurately, and the subsequent weighing operation continues; if the offset value exceeds the preset threshold, it is automatically determined to be an abnormal placement offset, and the robotic arm re-grabs the weight and corrects the placement position until the weight is placed in a position that meets the accuracy requirements.

[0041] Preferably, the method of the present invention further includes automatically generating a calibration report for the electronic scale after the preset weight of the weights has been calibrated. Specifically, after completing steps such as weight placement, weighing, and error judgment at multiple weight points, the system will automatically summarize the data collected throughout the calibration process and generate an electronic scale calibration report. The calibration report includes at least the following:

[0042] For each calibrated weight point, the system calculates the percentage error between the electronic scale display value and the actual mass of the weight, records the value, and uses it as the basis for judgment.

[0043] The number of times the weights are placed is recorded, and the actual number of times each weight is placed during the calibration process is recorded, which helps to evaluate whether the scale platform is level and the stability and placement accuracy of the robotic arm.

[0044] The AD value of an empty scale is obtained by zeroing the electronic scale before each weighing and collecting the AD value when the scale is empty.

[0045] The AD value of the weighing sensor is collected when the weights are weighed at various weight points, and thus serves as the underlying data for the sensor's response to the load.

[0046] The system automatically determines whether the weighing results are qualified or not based on preset error values ​​for each weight point, and provides a qualified or unqualified conclusion for the calibration results of the entire electronic scale.

[0047] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A method for calibrating an electronic scale based on a laser scanner, characterized in that, Includes the following steps: (1) The platform height of the electronic scale to be calibrated is obtained by using a laser matrix array, thereby constructing a three-axis positioning coordinate system; (2) A servo motor is used to drive the worktable that carries the electronic scale, so that the worktable can rise or fall. Based on the measurement data provided by the laser matrix array, the height of the electronic scale platform is adjusted to the reference working surface. (3) Mobilize the robotic arm and control it to grip the weight, while recording the gripping point of the weight, place the weight on the scale platform of the electronic scale, while recording the placement point of the weight, connect the positions of multiple gripping points and placement points to form a complete working path, and generate a repeatable loop command. (4) Obtain the real-time weight of the electronic scale, which is the displayed weight of the electronic scale. Compare the real-time weight with the actual weight of the weight to obtain the error value, wherein the error value = (real-time weight - actual weight) / actual weight × 100%. If the error value is less than 1%, the detection is considered normal; if the error value is greater than 1%, the detection is considered abnormal.

2. The electronic scale calibration method based on a laser scanner according to claim 1, characterized in that, The laser matrix array includes at least three sets of laser scanners, each with a frequency of 100Hz and an accuracy of 0.01mm.

3. The electronic scale calibration method based on a laser scanner according to claim 1, characterized in that, Step (3) also includes zeroing the electronic scale and obtaining the AD value of the electronic scale when it is empty; when the electronic scale is weighing, obtaining the AD value of the electronic scale and storing the AD value in the electronic scale and transmitting it to the database.

4. The electronic scale calibration method based on a laser scanner according to claim 1, characterized in that, Step (3) also includes switching the weights in multiple segments, and the weights include at least 6kg, 15kg and 30kg of different specifications.

5. The electronic scale calibration method based on a laser scanner according to claim 1, characterized in that, Step (4) also includes transmitting the detection results that are determined to be abnormal to the monitoring platform.

6. The electronic scale calibration method based on a laser scanner according to claim 1, characterized in that, The height of the electronic scale platform ranges from 150 to 450 mm, and the height of the reference working surface is 800 mm.

7. The electronic scale calibration method based on a laser scanner according to claim 2, characterized in that, Step (3) further includes that after the robotic arm completes the placement of the weight, the laser scanner continues to perform laser scanning on the placement position of the weight to determine whether the placement position of the weight has shifted, and when the shift value is greater than a preset threshold, the robotic arm is controlled to replace the weight.

8. The electronic scale calibration method based on a laser scanner according to claim 1, characterized in that, The method further includes generating a calibration report for the electronic scale after completing the calibration of the preset weight of the weight. The calibration report includes: the error value of each weight point, the number of placements, the AD value of the empty scale, the AD value of the weighed scale, and the judgment result of whether it is qualified.

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