Tachometer calibration device

Abstract

The invention discloses a tachometer calibration device, and relates to the field of tachometer calibration. The tachometer calibration device comprises a camera shooting unit, a rotating speed detection unit, a control processing unit and a calibration unit. The camera unit is used for shooting a tachometer of the target motor to obtain a meter display value image of the tachometer; the rotating speed detection unit is used for detecting rotating speed of a target motor and generating rotating speed detection signals; the control processing unit is respectively connected with the camera unit and the rotating speed detection unit, and is used for determining a meter display rotating speed value displayed by the tachometer according to the meter display value image, determining a rotating speed detection value of the target motor according to the rotating speed detection signal, determining that the tachometer needs to be calibrated according to the rotating speed detection value and the meter display rotating speed value, and generating a calibration processing signal; and the calibration unit is used for carrying out calibration processing on the tachometer according to the calibration processing signal. According to the method, the motor tachometer can be automatically and accurately measured and calibrated, the reading accuracy of the motor tachometer is ensured, the error of manual operation is reduced, and the reliability of calibration precision is improved.

Description

Technical Field

[0001] The invention relates to the technical field of tachometer calibration, and in particular to a tachometer calibration device. Background Art

[0002] The motor's tachometer is an important monitoring tool used to measure and display the motor's rotational speed in real time. It is essential to ensure that mechanical equipment operates according to predetermined parameters, and can help operators monitor the working status of the motor and promptly adjust or deal with possible problems. The tachometer can prevent equipment damage caused by abnormal speed and ensure the continuity and efficiency of the production line. Tachometer calibration is performed to ensure the accuracy and reliability of its measurement data. Due to environmental changes, equipment aging or other factors, the tachometer readings may deviate. Regular calibration can eliminate these errors and ensure that the motor operates in optimal conditions.

[0003] In the related art, the tachometer calibration method is usually to connect the motor tachometer to a calibration device. By comparing the reading displayed by the tachometer with the known speed provided by the calibration device, the operator can adjust the tachometer so that its reading is consistent with the standard speed.

[0004] However, this manual calibration method relies heavily on the operator's experience and judgment. Human errors increase the uncertainty in the calibration process, resulting in unreliable calibration accuracy. Summary of the invention

[0005] In view of the above-mentioned technical problems and defects, the purpose of the present invention is to provide a tachometer calibration device that can automatically and accurately measure and calibrate the motor tachometer, ensure the accuracy of its readings, reduce errors caused by human operation, and improve the reliability of calibration accuracy.

[0006] To achieve the above-mentioned purpose, the present invention provides a tachometer calibration device, including a camera unit, a speed detection unit, a control processing unit and a calibration unit; the camera unit is used to shoot the tachometer of the target motor to obtain a display value image of the tachometer; the speed detection unit is used to detect the speed of the target motor and generate a speed detection signal; the control processing unit is respectively connected to the camera unit and the speed detection unit, and is used to determine the displayed speed value displayed by the tachometer according to the display value image, determine the speed detection value of the target motor according to the speed detection signal, determine that the tachometer needs to be calibrated according to the speed detection value and the displayed speed value, and generate a calibration processing signal; the calibration unit is respectively connected to the tachometer and the control processing unit, and is used to calibrate the tachometer according to the calibration processing signal.

[0007] The present invention realizes the high efficiency and accuracy of tachometer calibration through a precise automated process. First, the camera unit captures the real-time image of the tachometer and uses image recognition technology to extract the displayed speed value. This process avoids human reading errors and ensures the objectivity and consistency of the speed value reading. Secondly, the speed detection unit uses a high-precision sensor to directly measure the actual speed of the motor and generate an accurate speed detection signal, thereby providing a reliable reference benchmark. The control processing unit is the core, and compares and analyzes the displayed speed value obtained by the camera unit with the actual speed value measured by the speed detection unit, identifies the deviation between the two, and calculates the necessary calibration parameters; based on these calibration parameters, the control processing unit generates a calibration processing signal to drive the calibration unit to automatically and accurately adjust the tachometer. This automated calibration process not only reduces the errors caused by human factors, but also improves the speed and efficiency of calibration. In addition, through real-time monitoring and continuous calibration, the device can ensure that the tachometer can provide accurate speed readings under various working conditions, thereby improving the reliability and stability of the entire system.

[0008] In some embodiments, the control processing unit is specifically used to call a preset tachometer display value recognition model, perform recognition processing on the display value image, and obtain the display speed value.

[0009] By adopting the technical solution of the above embodiment, the recognition accuracy and processing speed of the tachometer display value image are significantly improved by introducing a preset tachometer display value recognition model. The model is specifically optimized for the display characteristics of the tachometer and can efficiently extract speed information from the image. By using a well-trained machine learning model, the device can adapt to different display value representation methods, whether it is pointer type or digital type, and can accurately recognize it. In addition, the preset nature of the model means that it can be deployed quickly, reducing on-site debugging time and improving overall calibration efficiency.

[0010] In some embodiments, the training process of the tachometer display value recognition model includes: obtaining multiple display value sample images, the display value sample images include pointer-type display value sample images and digital display value sample images; marking the true values ​​of the pointer-type display value sample images and the true values ​​of the digital display value sample images in the display value sample images to obtain a training data set; training the selected machine learning model with the training data set to obtain a trained tachometer display value recognition model.

[0011] By adopting the technical solution of the above embodiment, a training process of a tachometer display value recognition model is provided, and the generalization ability and robustness of the model are enhanced by using a variety of sample images, including pointer-type and digital tachometers, and images under different lighting and stain conditions. This training method ensures that the model can still accurately recognize the tachometer reading when facing the changing conditions in the actual environment. In this way, the tachometer calibration device can provide more reliable and consistent calibration results and reduce errors caused by environmental factors.

[0012] In some embodiments, the sample images of displayed values ​​further include images of the tachometer under different lighting environments, and images of the tachometer affected by stains.

[0013] The technical solution of the above embodiment is adopted to further improve the practicality and accuracy of the calibration device by including tachometer images under different lighting environments and with the influence of stains as samples. This comprehensive sample consideration ensures that the device can accurately perform the calibration task even under extreme or undesirable conditions. This not only improves the accuracy of the calibration results, but also expands the application range of the device, enabling it to work reliably in a variety of industrial environments.

[0014] In some embodiments, the tachometer calibration device also includes a reminder unit, which is connected to the control processing unit. The control processing unit is used to determine, based on the displayed value image, that the surface stain obstruction range of the tachometer exceeds a set standard range, and generate a cleaning prompt instruction. The reminder unit is used to issue a reminder signal that the tachometer needs to be cleaned according to the cleaning prompt instruction.

[0015] By adopting the technical solution of the above embodiment, the user interaction function is added by integrating the reminder unit, which improves the convenience of operation and the intelligence of the device. When the control processing unit detects that the stains on the surface of the tachometer exceed the preset standard, the reminder unit will actively notify the user to clean it, thereby avoiding recognition errors and calibration failures caused by stains. This active reminder mechanism ensures the smooth progress of the calibration process and reduces the risk of repeated calibration due to unclear display value images.

[0016] In some embodiments, the tachometer calibration device further includes a signal processing unit, which is connected between the speed detection unit and the control processing unit, and is used to perform enhancement processing on the speed detection signal.

[0017] By adopting the technical solution of the above embodiment, the quality of the speed detection signal is improved by adding a signal processing unit between the speed detection unit and the control processing unit. The signal processing unit performs enhancement processing such as filtering and amplification on the original speed signal, ensuring that the control processing unit can receive a clear and accurate signal even under conditions of high noise or weak signal. This not only improves the accuracy of speed detection, but also enhances the reliability and stability of the entire calibration device.

[0018] In some embodiments, the calibration unit is further used to return a calibration completion signal to the control processing unit after the calibration is completed, and the control processing unit is further used to generate a calibration record report of the tachometer according to the calibration completion signal.

[0019] By adopting the technical solution of the above embodiment, the calibration record report generation function is integrated into the control processing unit, and combined with the feedback mechanism of the calibration unit, the calibration process is fully automated and the record management is automated. After the calibration is completed, the calibration unit will send a calibration completion signal to the control processing unit, and the control processing unit will generate a detailed calibration record report accordingly. This automated record management not only improves the calibration efficiency, but also facilitates subsequent data analysis and quality control.

[0020] In some embodiments, the tachometer calibration device further includes a wireless communication unit, which is connected to the control processing unit and is used to send a calibration record report to a user terminal of a staff member.

[0021] By adopting the technical solution of the above embodiment, the wireless transmission of the calibration record report is realized by integrating the wireless communication unit in the tachometer calibration device, which greatly improves the convenience of the staff and the accessibility of the calibration data. The staff can remotely receive the calibration record report through the user terminal device and monitor the calibration status and results in real time. This wireless communication function is particularly suitable for large factories or multi-regional facilities, which improves the flexibility and response speed of calibration work.

[0022] In some embodiments, the control processing unit is connected to a motor control unit of the target motor and is configured to send a speed control instruction to the motor control unit so that the motor control unit controls the speed of the target motor according to the speed control instruction.

[0023] By adopting the technical solution of the above embodiment, direct control of the target motor speed is achieved by connecting the control processing unit to the motor control unit of the target motor. This direct control mechanism allows the calibration device to adjust the motor speed as needed to perform accurate calibration. This not only improves the accuracy of the calibration, but also makes the calibration process more flexible and efficient, especially when calibration is required at a specific speed.

[0024] In some embodiments, the tachometer calibration device further includes a metal casing, and the control processing unit is disposed in the metal casing.

[0025] By adopting the technical solution of the above embodiment, a metal shell is designed for the tachometer calibration device, providing additional physical protection and environmental isolation. The metal shell not only protects the internal components from mechanical damage such as impact and fall, but also helps to shield external electromagnetic interference and ensure the accuracy of signal processing and data calculation. In addition, the metal shell also has corrosion resistance and can resist the influence of harsh environment, thereby improving the durability and reliability of the device and making it adaptable to the challenges of various industrial environments.

[0026] One or more technical solutions provided by the present invention have at least the following technical effects or advantages: 1. The tachometer calibration device of the present invention realizes full automation of the tachometer calibration process by integrating a camera unit, a speed detection unit, a control processing unit, a calibration unit and a wireless communication unit. This automation not only reduces the errors and labor intensity of manual operation, but also improves the efficiency and accuracy of calibration. By automatically acquiring the tachometer display value image, automatically detecting the actual speed of the motor, automatically performing image recognition, automatically comparing and analyzing data, automatically performing calibration operations, and automatically generating and sending calibration record reports, the device significantly improves the intelligent level of motor control and maintenance in industrial environments.

[0027] 2. The high-precision speed detection unit and advanced image recognition technology ensure accurate measurement and calibration of the motor speed. The speed detection unit uses a non-contact sensor to directly measure the motor speed and generate an accurate speed detection signal; the control processing unit calls a fully trained tachometer display value recognition model to accurately identify the speed value in the image. In addition, the enhanced processing of the signal processing unit further improves the quality of the signal. The combination of these technologies enables the device to provide high-precision speed measurement and calibration results to meet the strict accuracy requirements in industrial applications.

[0028] 3. Possess environmental adaptability and friendly user interaction. The present invention is capable of processing images under different lighting conditions and can accurately identify the tachometer readings even when obscured by stains. In addition, through the integration of a reminder unit, the device can actively remind the user to clean the tachometer when stains are detected to ensure the smooth calibration process. The addition of a wireless communication unit enables the calibration record report to be remotely transmitted to the user end, improving the convenience of the staff. The protection of the metal casing further improves the durability and reliability of the device in harsh industrial environments. These designs enable the tachometer calibration device to work stably in various environments, while providing users with a convenient operating experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings herein are incorporated into and constitute a part of the specification, showing embodiments consistent with the present invention, and together with the specification, are used to explain the principles of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. In the drawings: Figure 1 It is a schematic diagram of the structure and organization of a tachometer calibration device according to an embodiment of the present invention; Figure 2 It is a schematic diagram of the architecture of a tachometer calibration device according to an embodiment of the present invention.

[0030] Description of reference numerals: 1. Camera unit; 2. Speed ​​detection unit; 3. Control processing unit; 4. Calibration unit; 5. Reminder unit; 6. Signal processing unit; 7. Wireless communication unit. DETAILED DESCRIPTION

[0031] The terms used in the following embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to be limiting of the present invention. As used in the specification of the present invention, the singular expressions "a", "a", "above", "the" and "this" are intended to also include plural expressions, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used in the present invention refers to any or all possible combinations comprising one or more of the listed items.

[0032] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood as implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0033] It should also be noted that, unless otherwise clearly specified and limited, in the embodiments of the present invention, the terms such as "setting" and "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two components; it can be a wired communication connection or a wireless communication connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The embodiments of the present invention are described in detail below.

[0034] The embodiment of the present invention provides a tachometer calibration device, such as Figure 1As shown, it includes a camera unit 1, a rotation speed detection unit 2, a control processing unit 3 and a calibration unit 4.

[0035] The camera unit 1 is used to photograph the tachometer of the target motor to obtain an image of the displayed value of the tachometer.

[0036] The camera unit 1 can be composed of a high-resolution industrial camera, an adapter lens, a stable bracket and an image acquisition card. The camera unit 1 is designed to stably capture the image of the target motor tachometer under various environmental conditions. The industrial camera has high sensitivity and fast capture capabilities, and different exposure times and shutter speeds can be set to adapt to different lighting environments. The adapter lens ensures the clarity and focus accuracy of the image, which can be adjusted manually or automatically to obtain the best image quality. The camera unit 1 is mounted on a stable bracket, which allows precise adjustment of the angle and distance of the camera to ensure that the displayed value of the tachometer is in the center of the camera's field of view. The image acquisition card is responsible for transmitting the image captured by the camera to the control processing unit 3 for further processing and analysis. Through these designs, the camera unit 1 can accurately capture the displayed value image of the tachometer and provide reliable visual data input for the tachometer calibration device.

[0037] The rotation speed detection unit 2 is used to detect the rotation speed of the target motor and generate a rotation speed detection signal.

[0038] The speed detection unit 2 may include one or more non-contact speed sensors, such as a photoelectric sensor, a Hall effect sensor, or a magnetoelectric sensor. These speed sensors use physical effects to detect the speed of the motor shaft. For example, the photoelectric sensor works by emitting light and detecting the light reflected by the rotating parts of the motor (such as a disk with a reflective mark); the Hall effect sensor uses the Hall effect to detect the change in the magnetic field caused by the rotating parts. The sensor is installed near the motor to ensure that its detection head is properly aligned with the rotating parts to accurately capture the speed information. The raw signal output by the speed sensor is usually a pulse sequence, and each pulse corresponds to a rotation cycle of the motor shaft. The electronic processing system inside the speed detection unit 2 counts and times these pulses to calculate the real-time speed of the motor.

[0039] Then, the speed detection unit 2 converts the calculation result into a corresponding speed detection signal, which can be an analog voltage, a digital value or serial data, and transmits it to the control processing unit 3 for comparison and analysis to determine whether the tachometer needs to be calibrated. This high-precision speed detection method provides a reliable reference benchmark to ensure the accuracy and reliability of the calibration process.

[0040] The control processing unit 3 is connected to the camera unit 1 and the speed detection unit 2 respectively, and is used to determine the displayed speed value displayed by the tachometer according to the displayed value image, determine the speed detection value of the target motor according to the speed detection signal, determine that the tachometer needs to be calibrated according to the speed detection value and the displayed speed value, and generate a calibration processing signal.

[0041] Specifically, the control processing unit 3 is the core of the tachometer calibration device, responsible for processing and analyzing the data from the camera unit 1 and the speed detection unit 2. First, the control processing unit 3 receives the displayed value image of the tachometer captured by the camera unit 1, and uses the built-in image processing algorithm to pre-process the image, such as denoising, contrast enhancement, etc., to improve the recognition accuracy of the displayed value. Then, through the optical character recognition (OCR) technology, the speed value in the image is converted into a digital signal, so as to determine the displayed speed value displayed by the tachometer.

[0042] Next, the control processing unit 3 receives the pulse speed detection signals generated by the speed detection unit 2, which are proportional to the physical speed of the target motor. By counting the number of pulses within a certain period of time and combining the specification parameters of the sensor, the control processing unit 3 calculates the actual speed of the motor and generates a speed detection value.

[0043] Finally, the control processing unit 3 compares the displayed speed value with the speed detection value. If there is a significant difference between the two, it indicates that the reading of the tachometer is inaccurate and needs to be calibrated.

[0044] Specifically, the control processing unit 3 compares the error value between the displayed speed value and the speed detection value, combines the performance parameters of the tachometer and the historical calibration data, and uses a mathematical model and a calibration strategy to calculate the amount that needs to be adjusted, that is, the calibration parameter.

[0045] For example, the mathematical model can use a linear regression model to determine the linear relationship between the displayed speed value and the actual speed detection value, thereby calculating the calibration parameters. If the error exhibits nonlinear characteristics, polynomial regression or other nonlinear models may be used to more accurately describe this relationship. In addition, the least squares method can also be used to find the best fit line by minimizing the sum of squares of the errors to determine the calibration parameters.

[0046] The calibration strategy involves how to apply these mathematical models to implement effective calibration. It may include selecting key calibration points that represent the performance of the tachometer over the entire range; determining the order of calibration, calibrating the high or low end of the range first, or using a step-by-step calibration method to gradually approach the ideal value; and calculating the calibration step value, that is, the amount of each adjustment, to avoid over-adjustment or under-adjustment. The calibration strategy may also include an iterative process, in which the control processing unit 3 updates the model parameters based on the results of each calibration until the preset accuracy requirements are met. In addition, an adaptive algorithm can be introduced to dynamically adjust the calibration strategy based on real-time feedback from the tachometer response to improve the accuracy and efficiency of the calibration.

[0047] The calibration parameters may include, but are not limited to: the magnitude of adjustment (such as the increase or decrease in the speed value), the step size of the adjustment, the rate of adjustment, and in some cases, it may be necessary to compensate for environmental factors (such as the effect of temperature and humidity on the tachometer reading). The calculated calibration parameters are packaged into a calibration processing signal, which clearly indicates in a certain format (which may be a digital quantity, an analog voltage or a serial data) how the calibration unit 4 should adjust the tachometer to eliminate the error.

[0048] The calibration processed signals are then transmitted to the calibration unit 4 which performs the actual calibration actions based on these signals, such as changing the mechanical pointer position of the tachometer by fine-tuning the adjustment mechanism driven by the motor, or correcting the counter threshold of the tachometer by electronic adjustment.

[0049] During the whole process, the control processing unit 3 may also monitor the calibration results in real time to ensure that the calibration operation achieves the expected accuracy. If the calibration results do not meet expectations, the control processing unit 3 will continue to adjust the calibration parameters based on feedback until the tachometer reading is consistent with the actual speed.

[0050] These calibration processing signals will be sent to the calibration unit 4 to instruct it to perform accurate calibration operations on the tachometer to eliminate errors and ensure that the reading of the tachometer is consistent with the actual speed of the motor. The whole process is highly automated, reducing human intervention and improving the efficiency and accuracy of calibration.

[0051] In this embodiment, the control processing unit may adopt various types of electronic devices, including but not limited to microcontrollers (MCU), digital signal processors (DSP), microprocessors (MPU), systems on chip (SoC), programmable logic controllers (PLC), single board computers (SBC), embedded computer modules, field programmable gate arrays (FPGA), and application specific integrated circuits (ASIC). The selection of these devices depends on the required processing power, power consumption, cost-effectiveness, software support, and specific application requirements. For example, an MCU may be selected for resource-constrained and cost-effective applications, while an MPU or SBC may be selected for applications that need to run complex algorithms and process large amounts of data.

[0052] The calibration unit 4 is connected to the tachometer and the control processing unit 3 respectively, and is used to calibrate the tachometer according to the calibration processing signal.

[0053] The calibration unit 4 is the part of the tachometer calibration device that is responsible for implementing the calibration operation, and is usually composed of a precise fine-tuning mechanism and an actuator. When the control processing unit 3 determines that the tachometer needs to be calibrated, it will send a detailed calibration processing signal to the calibration unit 4. These calibration processing signals include specific parameters and adjustment amounts required for calibration. These signals may also include specific types of calibration, such as whether it is an adjustment for mechanical deviation or correction of electronic display, and the amplitude of the adjustment, that is, the specific value or range that needs to be changed.

[0054] After receiving these signals, the calibration unit 4 first performs signal analysis to clarify the specific requirements of the calibration. After the analysis is completed, the fine-tuning mechanism begins to perform the calibration task. The fine-tuning mechanism may include one or more micro-motors, which drive adjustment screws through precise control to fine-tune the mechanical parts of the tachometer, such as gears or pointer positions. This mechanical adjustment can very accurately eliminate mechanical deviations and ensure the correct alignment of the pointer or reading.

[0055] At the same time, the calibration unit 4 may also use piezoelectric ceramic elements for fine adjustment. This technology is based on the piezoelectric effect, that is, by applying voltage to cause the ceramic element to produce a slight deformation, thereby achieving fine adjustment of the tachometer reading. This adjustment method is particularly suitable for digital tachometers and can accurately correct electronic display deviations.

[0056] Whether it is through the adjustment screw driven by the micro motor or the piezoelectric ceramic element, the calibration unit 4 can achieve precise adjustment of the tachometer to ensure that its reading is consistent with the actual speed of the motor, thereby meeting the requirements of high-precision calibration.

[0057] During the adjustment process, the calibration unit 4 may monitor the output of the tachometer in real time to ensure that the adjustment achieves the desired effect. If necessary, it can also perform multiple fine-tuning and checks to ensure that the tachometer reading accurately matches the actual speed of the motor. Once the calibration is completed and the tachometer display value is consistent with the actual speed value provided by the control processing unit 3, the calibration unit 4 will stop adjusting and may send a confirmation signal back to the control processing unit 3, indicating that the calibration process has been successfully completed.

[0058] This automated calibration process ensures precision and repeatability of the operation, greatly improving the efficiency and accuracy of calibration.

[0059] The tachometer calibration device of the present invention realizes the high efficiency and accuracy of tachometer calibration through a precise automated process. First, the camera unit 1 captures the real-time image of the tachometer and uses image recognition technology to extract the displayed speed value. This process avoids human reading errors and ensures the objectivity and consistency of the speed value reading. Secondly, the speed detection unit 2 uses a high-precision sensor to directly measure the actual speed of the motor and generate an accurate speed detection signal, thereby providing a reliable reference benchmark. The control processing unit 3 is the core, and compares and analyzes the displayed speed value obtained by the camera unit 1 with the actual speed value measured by the speed detection unit 2, identifies the deviation between the two, and calculates the necessary calibration parameters; based on these calibration parameters, the control processing unit 3 generates a calibration processing signal and drives the calibration unit 4 to automatically and accurately adjust the tachometer. This automated calibration process not only reduces the errors caused by human factors, but also improves the speed and efficiency of calibration. In addition, through real-time monitoring and continuous calibration, the device can ensure that the tachometer can provide accurate speed readings under various working conditions, thereby improving the reliability and stability of the entire system.

[0060] In some embodiments, the control processing unit 3 is specifically used to call a preset tachometer display value recognition model, perform recognition processing on the display value image, and obtain the display speed value.

[0061] The tachometer display value recognition model is usually constructed based on machine vision and image processing technology. This model is specially designed to accurately extract the displayed speed value from the tachometer image captured by the camera unit 1.

[0062] For pointer-type tachometers, the tachometer display value recognition model uses image preprocessing steps such as grayscale and filtering to clearly identify the tachometer pointer and scale. It then uses edge detection technology to determine the exact position of the pointer and determines the speed value based on the relative position of the pointer and scale. For a digital tachometer, the model might use optical character recognition (OCR) technology to learn the characteristics of different digits through a training dataset to achieve high-accuracy recognition.

[0063] In addition, the tachometer display value recognition model may also include a correction mechanism to handle distortion or tilt in the image to ensure the robustness of the recognition process. The performance of the model is improved through continuous training and optimization to adapt to different tachometer types, sizes and environmental conditions. Finally, the model converts the display value in the image into a digital format for further analysis and calibration by the control processing unit 3.

[0064] Specifically, the training process of the tachometer display value recognition model includes: First, a plurality of meter display value sample images are obtained, wherein the meter display value sample images include pointer-type meter display value sample images and digital meter display value sample images.

[0065] Specifically, image data can be collected from a variety of analog and digital tachometers. To ensure that the model can handle a variety of different display scenarios, these images should be captured under a variety of environmental conditions, including different lighting, angles, backgrounds, and tachometer specifications. Specialized camera equipment can be used to aim at the tachometer and record images at different speeds of the motor to ensure that the sample images cover the full range of the tachometer.

[0066] Then, the true values ​​of the pointer-type display value sample images and the true values ​​of the digital display value sample images are marked in the display value sample images to obtain a training data set.

[0067] Among them, for the sample images of pointer-type meter display values, the pointer position of the tachometer can be identified and marked by experts, and corresponded to the specific speed value; while for the sample images of digital meter display values, it is necessary to identify each digit displayed on the tachometer, and concatenate these digits into actual speed values.

[0068] Finally, the selected machine learning model is trained using the training data set to obtain a trained tachometer display value recognition model.

[0069] For digital meter display value sample images, a convolutional neural network (CNN) may be used to identify and classify the numbers in the image; for pointer meter display value sample images, a regression model may be used to predict the speed value pointed by the pointer. During the training process, the model will continuously adjust its own parameters to reduce the difference between the predicted value and the actual labeled value. Through repeated training and verification, the final model will be able to accurately identify the display value of the tachometer on new, unseen images.

[0070] In this embodiment, the selected machine learning model is trained using a training data set. This process includes adjusting model parameters, using techniques such as cross-validation to evaluate the performance of the model, and selecting the best model structure and hyperparameters.

[0071] After that, the accuracy and robustness of the model need to be tested on an independent validation dataset. Based on the test results, the model is adjusted and optimized to improve its predictive performance on unknown data.

[0072] Once the model performs well in the validation phase, it can be deployed to an actual tachometer calibration setup for real-time tachometer display value recognition.

[0073] In some embodiments, the sample images of displayed values ​​further include images of the tachometer under different lighting environments, and images of the tachometer affected by stains.

[0074] This allows for diversity in the sample images. During the training of the tachometer display value recognition model, in order to ensure that the model is highly adaptable and accurate in practical applications, the sample images need to be diverse. This includes collecting tachometer images under different lighting environments, as well as tachometer images affected by stains. For the lighting environment, the sample images should cover a variety of lighting conditions from strong light to dim light, including direct sunlight, indoor lighting, and cloudy days. The purpose of this is to allow the model to learn to accurately identify the tachometer display value under various lighting conditions, and to improve its robustness in different time periods and locations.

[0075] At the same time, considering that the tachometer may accumulate dust, oil or other stains during use, making image recognition difficult, it is also critical to collect and include these affected sample images in the training process. These images contain tachometer readings that are obscured by stains, blurred or partially displayed, allowing the model to learn how to accurately recognize tachometer values ​​in the presence of stains or damage that are common in real environments.

[0076] By training on these diverse sample images, the tachometer display value recognition model can be better generalized to various practical scenarios, improving its recognition accuracy and reliability in complex environments.

[0077] In some embodiments, the camera unit 1 may be affected by the vibration of the motor when acquiring the tachometer image, resulting in blurred images and affecting the accurate recognition of the tachometer display value. In order to solve this problem, the camera unit 1 usually integrates image stabilization technology, which reduces the impact of vibration on image clarity through software algorithms or hardware devices. Software algorithms may include multi-frame fusion, motion compensation and other technologies, which synthesize a stable image by comparing the differences between consecutive frames, predicting vibration trends and adjusting image data accordingly. In terms of hardware, an optical stabilization system or a mechanical anti-shake device may be used, such as using a gyroscope to detect the vibration of the camera and drive the compensation mechanism to move in the opposite direction to offset the vibration. Through these image stabilization measures, the camera unit 1 can provide a clear and stable tachometer image, providing high-quality visual input for the tachometer display value recognition model, thereby improving the recognition accuracy of the tachometer and the reliability of the entire calibration system.

[0078] In some embodiments, Figure 2 As shown, the tachometer calibration device further includes one or more of a reminder unit 5 , a signal processing unit 6 , and a wireless communication unit 7 .

[0079] The reminder unit 5 is connected to the control processing unit 3. The control processing unit 3 is used to determine that the surface stain obstruction range of the tachometer exceeds the set standard range based on the display value image, and generate a cleaning reminder instruction. The reminder unit 5 is used to issue a reminder signal that the tachometer needs to be cleaned according to the cleaning reminder instruction.

[0080] Specifically, when the control processing unit 3 analyzes the displayed value image captured by the camera unit 1, it will evaluate whether there are stains or other visual obstacles in the display area of ​​the tachometer in the image, and determine whether these stains have reached the preset standard range that affects the recognition accuracy. If the stain obstruction range exceeds this range, the control processing unit 3 will generate a cleaning prompt instruction, which clearly indicates that the tachometer needs to be cleaned. Subsequently, the control processing unit 3 passes this instruction to the reminder unit 5, and the reminder unit 5 immediately sends a reminder signal to the operator in a visual or audio manner, such as a flashing warning light or a buzzer, to remind the operator that there is obvious stain obstruction on the surface of the tachometer, and cleaning is required to ensure the accuracy of image recognition and calibration. This process ensures that the surface of the tachometer is clean before calibration, thereby avoiding misreading or calibration failure due to stains.

[0081] The signal processing unit 6 is connected between the rotation speed detection unit 2 and the control processing unit 3 , and is used for performing enhancement processing on the rotation speed detection signal.

[0082] The signal processing unit 6 is mainly responsible for processing and optimizing the original speed detection signal output by the speed detection unit 2. The signal processing unit 6 uses a series of signal processing techniques, such as filtering, amplification and digital processing, to improve the quality of the signal. Specifically, it may include a bandpass filter to remove high-frequency noise or low-frequency drift generated when the motor is running, so that only the useful signal part containing the speed information is retained. In addition, the signal processing unit 6 may also include an amplifier to enhance the strength of the signal to ensure that the control processing unit 3 can accurately receive and analyze these signals even in the case of weak signals. Finally, the enhanced analog signal is converted into a digital signal through an analog-to-digital converter (ADC) for further data analysis and processing by the control processing unit 3. Through these enhanced processes, the accuracy and reliability of the speed detection signal have been significantly improved, providing a solid foundation for the precise calibration of the tachometer.

[0083] The calibration unit 4 is further used to return a calibration completion signal to the control processing unit 3 after the calibration is completed. The control processing unit 3 is further used to generate a calibration record report of the tachometer according to the calibration completion signal.

[0084] Specifically, after completing the calibration process of the tachometer, the calibration unit 4 sends a calibration completion signal to the control processing unit 3, which is a key feedback mechanism to inform the control processing unit 3 that the calibration process has ended. After receiving this signal, the control processing unit 3 will perform the final processing steps, including verifying whether the calibration result meets the preset accuracy standard and generating a detailed tachometer calibration record report.

[0085] The calibration record report usually contains the calibration date, time, motor information, initial error value, calibration parameters, calibration results and any other diagnostic information. The calibration record report not only provides the operator with detailed calibration results, but also facilitates future maintenance and audit work.

[0086] In addition, the control processing unit 3 may also store the report in a database, or send it to a host computer or other management system through an interface to facilitate remote monitoring and long-term data tracking. This process ensures the transparency and traceability of the calibration activities and enhances the quality and efficiency of the entire calibration process.

[0087] The tachometer calibration device further includes a wireless communication unit 7, which is connected to the control processing unit 3 and is used to send a calibration record report to a user terminal of a staff member.

[0088] In this embodiment, the tachometer calibration device enhances its functionality and flexibility by integrating a wireless communication unit 7, which is connected to the control processing unit 3 and is mainly responsible for wirelessly transmitting the calibration record report generated during the calibration process to the user-end device of the staff. The wireless communication unit 7 may use common wireless communication protocols and technologies, such as Wi-Fi, Bluetooth, cellular networks (4G / 5G), etc., to achieve real-time remote transmission of data. In this way, the staff can remotely monitor the calibration status of the tachometer and receive the calibration results in time without having to check on site in person, which greatly improves work efficiency.

[0089] Furthermore, the wireless communication unit 7 can also support cloud storage and remote access of data, so that calibration record reports can be shared and analyzed by multiple authorized users, facilitating centralized management and maintenance. This wireless communication function is particularly suitable for large factories or distributed facilities, where tachometers may be installed in different locations and staff need to flexibly monitor and manage from a central control room or on mobile devices.

[0090] In some embodiments, the control processing unit 3 is connected to a motor control unit of the target motor, and is used to send a speed control instruction to the motor control unit, so that the motor control unit controls the speed of the target motor according to the speed control instruction.

[0091] The control processing unit 3 is connected to the motor control unit of the target motor to achieve direct control of the motor speed. During the tachometer calibration process, the control processing unit 3 generates accurate speed control instructions according to the preset calibration program or the operator's input. These instructions are sent to the motor control unit through the communication interface, and the motor control unit then interprets these instructions and adjusts the operating state of the motor accordingly, such as adjusting the power supply, changing the drive current or modifying the drive frequency, so as to achieve accurate control of the target motor speed.

[0092] In this way, the control processing unit 3 can ensure that the motor runs at a specific speed point according to the requirements of the calibration procedure, thereby providing a stable and known speed reference for the tachometer. This not only improves the automation of the calibration process, but also ensures the accuracy and reliability of the calibration results. In addition, this connection also allows the tachometer calibration device to control the motor in real time when necessary to adapt to different calibration requirements and scenarios, thereby enhancing the flexibility and practicality of the entire system.

[0093] In some embodiments, the tachometer calibration device further includes a metal casing, and the control processing unit 3 is disposed in the metal casing.

[0094] The metal housing of the tachometer calibration device is designed to protect the internal control processing unit 3 and possible other sensitive electronic components. This sturdy metal housing not only provides physical protection to prevent the device from being hit, dropped, and other forms of mechanical damage, but also helps to shield external electromagnetic interference and ensure the accuracy of signal processing and data calculation of the control processing unit 3.

[0095] The metal housing is usually made of corrosion-resistant materials and can withstand the influence of harsh environments such as humidity, dust, oil and chemicals, thereby improving the durability and reliability of the device. In addition, the design of the metal housing also takes into account the heat dissipation performance, ensuring that the control processing unit 3 can maintain a suitable temperature even after long-term operation to avoid performance degradation or damage caused by overheating. By integrating key components such as the control processing unit 3 into the metal housing, the tachometer calibration device can operate stably in various industrial environments and meet the needs of long-term and frequent use.

[0096] The tachometer calibration device of this embodiment adopts a precise and automated process to ensure the accuracy and reliability of the motor tachometer. The following is a detailed workflow: 1. Start the device: Turn on the power supply to start the tachometer calibration device, including the control processing unit 3, the camera unit 1, the speed detection unit 2 and the wireless communication unit 7.

[0097] 2. Image capture: The camera unit 1 is aimed at the tachometer of the target motor and takes images of the tachometer. These images include pointer or digital meter display values ​​and may be acquired under different lighting conditions and environmental conditions.

[0098] 3. Image stabilization: The camera unit 1 uses image stabilization technology to cope with image blur caused by motor vibration and ensure image clarity.

[0099] 4. Speed ​​detection: The speed detection unit 2 detects the actual speed of the target motor using a corresponding sensor and generates a speed detection signal.

[0100] 5. Signal processing: The signal processing unit 6 performs enhancement processing on the speed detection signal to ensure the quality and accuracy of the signal.

[0101] 6. Image recognition: The control processing unit 3 calls the tachometer display value recognition model to perform recognition processing on the display value image captured by the camera unit 1 to obtain the display speed value.

[0102] 7. Comparative analysis: The control processing unit 3 compares the displayed speed value with the speed detection value to determine whether there is a difference and whether calibration is required.

[0103] 8. Calibration processing: If calibration is required, the control processing unit 3 calculates the calibration parameters and generates a calibration processing signal, which is sent to the calibration unit 4 for the actual calibration operation.

[0104] 9. Feedback signal: After completing the calibration, the calibration unit 4 returns a calibration completion signal to the control processing unit 3.

[0105] 10. Record report: The control processing unit 3 generates a calibration record report of the tachometer and can send it to the user end of the staff through the wireless communication unit 7.

[0106] 11. Controlling the motor speed: When necessary, the control processing unit 3 sends a speed control instruction to the motor control unit of the target motor to adjust the motor speed to a specific value required for calibration.

[0107] 12. Reminder for cleaning: If it is found during the image recognition process that the tachometer surface is blocked by dirt beyond the set standard, the control processing unit 3 will generate a cleaning reminder instruction, and the reminder unit 5 will send a cleaning reminder signal.

[0108] 13. End of calibration: After completing the calibration process, the tachometer calibration device can continue to monitor the motor speed, or wait for the next calibration instruction.

[0109] The entire workflow is automated, reducing human intervention and improving the efficiency and accuracy of calibration. At the same time, through the wireless communication unit 7, the staff can remotely monitor the calibration process and results, improving the convenience of work.

[0110] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A tachometer calibration device, characterized in that: include: A camera unit, used for photographing the tachometer of the target motor to obtain an image of the displayed value of the tachometer; A rotation speed detection unit, used to detect the rotation speed of the target motor and generate a rotation speed detection signal; a control processing unit, connected to the camera unit and the speed detection unit, respectively, for determining a displayed speed value displayed by the tachometer according to the displayed value image, determining a speed detection value of the target motor according to the speed detection signal, determining that the tachometer needs calibration processing according to the speed detection value and the displayed speed value, and generating a calibration processing signal; The calibration unit is connected to the tachometer and the control processing unit respectively, and is used to calibrate the tachometer according to the calibration processing signal.

2. The tachometer calibration device according to claim 1, characterized in that: The control processing unit is specifically used to call a preset tachometer display value recognition model, perform recognition processing on the display value image, and obtain the display speed value.

3. The tachometer calibration device according to claim 2, characterized in that: The training process of the tachometer display value recognition model includes: Acquire a plurality of meter display value sample images, wherein the meter display value sample images include pointer-type meter display value sample images and digital meter display value sample images; Marking the true value of the pointer-type meter display value sample image and the true value of the digital meter display value sample image in the meter display value sample image to obtain a training data set; The selected machine learning model is trained using the training data set to obtain a trained tachometer display value recognition model.

4. The tachometer calibration device according to claim 3, characterized in that: The sample images of displayed values ​​also include images of the tachometer under different lighting environments and images of the tachometer affected by stains.

5. The tachometer calibration device according to any one of claims 1 to 4, characterized in that: It also includes a reminder unit, which is connected to the control processing unit. The control processing unit is used to determine, based on the display value image, that the surface stain obstruction range of the tachometer exceeds a set standard range, and generate a cleaning reminder instruction. The reminder unit is used to issue a reminder signal that the tachometer needs to be cleaned according to the cleaning reminder instruction.

6. The tachometer calibration device according to claim 1, characterized in that: It also includes a signal processing unit, which is connected between the rotation speed detection unit and the control processing unit, and is used for enhancing the rotation speed detection signal.

7. The tachometer calibration device according to claim 1, characterized in that: The calibration unit is further used to return a calibration completion signal to the control processing unit after the calibration is completed, and the control processing unit is further used to generate a calibration record report of the tachometer according to the calibration completion signal.

8. The tachometer calibration device according to claim 7, characterized in that: It also includes a wireless communication unit, which is connected to the control processing unit and is used to send the calibration record report to a user terminal of a staff member.

9. The tachometer calibration device according to claim 1, characterized in that: The control processing unit is connected to the motor control unit of the target motor and is used to send a speed control instruction to the motor control unit so that the motor control unit controls the speed of the target motor according to the speed control instruction.

10. The tachometer calibration device according to claim 1, characterized in that: It also includes a metal shell, in which the control processing unit is arranged.

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