Motor vehicle license plate angle measuring instrument

Abstract

The utility model discloses a motor vehicle license plate angle measuring instrument which comprises a horizontal ruler rod and an attaching rod, and one end of the horizontal ruler rod is hinged to one end of the attaching rod. A gradienter is arranged in the horizontal ruler rod to determine a horizontal reference surface; the attaching rod is a curve shape taking rod or a magnetic attraction rod, and the contact end of the attaching rod is provided with a deformable attaching layer or a magnetic attraction material so as to be tightly attached to the plane of the number plate. A digital angle sensor and a display unit are arranged at the hinged position of the horizontal ruler rod and the attaching rod, the angle sensor is electrically connected with the display unit, and the display unit can display included angle data measured by the digital angle sensor in real time. According to the method, data distortion caused by poor fitting is avoided, the problem that a traditional rigid tool cannot be fitted with a complex surface is solved, man-made misjudgment is reduced, and the accuracy and authority of the law enforcement and inspection process are ensured.

Description

A motor vehicle license plate angle measuring instrument Technical Field

[0001] This application relates to license plate angle measuring equipment, specifically to a motor vehicle license plate angle measuring instrument. Background Technology

[0002] High-precision adaptive license plate angle measurement refers to the real-time and accurate detection and correction of the license plate posture under different tilt angles, lighting conditions, and complex backgrounds in scenarios such as vehicle recognition and traffic monitoring, through image processing and computer vision technology. This improves the robustness and recognition rate of the license plate recognition system. Its core lies in combining edge detection, feature matching, and deep learning algorithms to achieve automatic recognition and compensation of the license plate angle, thereby providing high-quality image input for subsequent character recognition.

[0003] Overcoming the problem that existing measuring tools cannot stably adhere to license plates under complex surface conditions, resulting in large errors in longitudinal angle measurement; and realizing the intelligent recognition function of the equipment so that it can automatically determine whether the license plate meets the angle requirements in the standard, thereby improving detection efficiency and accuracy, are the technical problems that urgently need to be solved. Summary of the Invention

[0004] In view of this, the present application aims to provide a motor vehicle license plate angle measuring instrument to at least solve the above-mentioned technical problems.

[0005] To achieve the above objectives, the technical solution of this application is implemented as follows:

[0006] This application provides a motor vehicle license plate angle measuring instrument, which includes a horizontal ruler and a fitting rod, with one end of the horizontal ruler and the fitting rod respectively hinged together.

[0007] The horizontal ruler rod has a built-in level to determine the horizontal reference plane; the bonding rod is a curved shaping rod or a magnetic rod, and its contact end is provided with a deformable bonding layer or magnetic material to tightly fit the plate plane.

[0008] A digital angle sensor and a display unit are provided at the hinge joint between the horizontal ruler and the fitting rod. The angle sensor and the display unit are electrically connected, and the display unit can display the included angle data measured by the digital angle sensor in real time.

[0009] In the above scheme, the curve shaping rod includes a multi-segment rod structure, each segment of the rod structure is provided with size scale information, and the multi-segment rod structure is movably connected to form a ruler-shaped structure.

[0010] In the above scheme, the contact end of the curved forming rod is made of flexible material, and at least one surface of the curved forming rod is covered with an anti-slip rubber layer.

[0011] In the above scheme, a permanent magnet block is embedded in the contact end of the magnetic suction rod.

[0012] In the above scheme, both the horizontal ruler and the fitting rod are made of aluminum alloy, and the surface of the aluminum alloy has been anodized.

[0013] In the above scheme, the length of the horizontal ruler and the fitting rod are both 200mm to 300mm, and the overall weight is less than or equal to 500g.

[0014] In the above scheme, the angle measuring instrument also includes an angle locking mechanism, which can fix the relative position between the horizontal ruler and the fitting rod during the measurement process.

[0015] The vehicle license plate angle measuring instrument of this application adopts a high-precision digital angle sensor (±0.1°) and an electronic level sensor (±0.05°) to replace the traditional manual visual reading method, effectively solving the problem of measurement errors as high as ±1° to ±5° in the prior art, and ensuring that it meets the accurate detection requirements of the GA36-2018 standard for 15° and 30° thresholds. Through two bonding methods—flexible curve forming rod and magnetic suction rod—it can flexibly adapt to non-planar structures such as motorcycle license plate openings and new energy vehicle curved license plates, as well as metal surfaces, avoiding data distortion caused by poor bonding and solving the problem that traditional rigid tools cannot bond to complex surfaces. Integrating a digital measurement system and an intelligent display module, it realizes automatic angle calculation, real-time display, three-color backlight prompts, and standard threshold comparison functions, eliminating the need for manual calculation and shortening the single measurement time to less than 10 seconds, greatly improving work efficiency in batch inspection scenarios. The measuring instrument has a built-in GA36-2018 standard dynamic comparison bar, which can directly determine whether the license plate installation is compliant, reducing human error and ensuring the accuracy and authority of the law enforcement and inspection process. Attached Figure Description

[0016] Figure 1 is a schematic diagram of the structural composition of the motor vehicle license plate angle measuring instrument according to an embodiment of this application. Detailed Implementation

[0017] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] The specific technical features described in the various embodiments in the detailed implementation can be combined in various ways without contradiction. For example, different implementation methods can be formed by combining different specific technical features. In order to avoid unnecessary repetition, the various possible combinations of the specific technical features in this application will not be described separately.

[0019] It should be noted that the terms "first," "second," and "third" used in the embodiments of this application are merely to distinguish similar objects and do not represent a specific order of objects. It is understood that "first," "second," and "third" can be interchanged in a specific order or sequence where permitted. It should be understood that the objects distinguished by "first," "second," and "third" can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in an order other than those illustrated or described herein.

[0020] This application describes a vehicle license plate angle measuring instrument, aiming to solve the problems of insufficient measurement accuracy, poor adaptability to curved surfaces, and low operating efficiency in the prior art. The device adopts an integrated design, combining a high-precision sensor with an adaptive bonding structure to achieve rapid and accurate measurement of the installation angle of vehicle license plates. The vehicle license plate angle measuring instrument of this application adopts a hinged double-rod structure, consisting of a horizontal ruler rod 10 and a bonding rod 20 hinged together by a high-precision shaft pin 30, forming a measuring arm that can rotate from 0° to 360°, ensuring a wide and flexible measurement range.

[0021] Figure 1 is a schematic diagram of the structure of the motor vehicle license plate angle measuring instrument according to an embodiment of this application. As shown in Figure 1, the angle measuring instrument according to an embodiment of this application includes a horizontal ruler 10 and a fitting rod 20. One end of the horizontal ruler 10 and the fitting rod 20 are hinged together by a high-precision shaft pin 30. The horizontal ruler 10 has a built-in level 11 to determine the horizontal reference plane. The fitting rod 20 is a curved shaping rod or a magnetic rod, and its contact end is provided with a deformable fitting layer or magnetic material to tightly fit the license plate plane. A digital angle sensor and a display unit 40 are provided at the hinge of the horizontal ruler 10 and the fitting rod 20. The angle sensor and the display unit are electrically connected, and the display unit 40 can display the included angle data measured by the digital angle sensor in real time.

[0022] In this embodiment, the curved forming rod comprises a multi-segment structure, each segment having dimensional scale information. The multi-segment structure is movably connected to form a ruler-shaped structure. The contact end of the curved forming rod is made of a flexible material, and at least one surface of the curved forming rod is covered with an anti-slip rubber layer. A permanent magnet is embedded in the contact end of the magnetic rod.

[0023] In this embodiment, both the horizontal ruler 10 and the fitting rod 20 are made of aluminum alloy, and the surface of the aluminum alloy has undergone anodizing treatment. The length of both the horizontal ruler 10 and the fitting rod 20 is 200mm to 300mm, and their overall weight is less than or equal to 500g.

[0024] The angle measuring instrument in this application embodiment also includes an angle locking mechanism, which can fix the relative position between the horizontal ruler and the fitting rod during the measurement process.

[0025] The level rod 10 in this embodiment incorporates a dual level calibration device, including a mechanical bubble level 11 and an electronic level sensor 12, with accuracies of ±0.5° and ±0.05° respectively, providing a reliable reference for measurement. The fitting rod 20 offers two adaptive fitting methods: a flexible curve forming rod and a magnetic suction rod. The contact end of the flexible curve forming rod uses an anti-slip rubber layer with a surface friction coefficient ≥0.8 and incorporates a multi-section movable ruler-shaped structure, allowing it to fit non-planar structures such as motorcycle license plate nozzles. The magnetic suction rod embeds a permanent magnet with an attraction force ≥5N, capable of penetrating paint layers below 0.5mm, suitable for stable adhesion to metal surfaces. A high-precision digital angle sensor is integrated at the hinge, with a measurement range of 0°~360°, a resolution of 0.01°, an accuracy of ±0.1°, and a response time ≤0.5 seconds, significantly improving measurement accuracy and speed. The intelligent display and processing module uses an OLED LCD screen with an integrated STM32F4 processor, featuring real-time angle display, three-color backlight indication, standard threshold comparison, and data storage functions, meeting the requirements of the GA36-2018 standard for longitudinal angle. Furthermore, the angle locking mechanism in this embodiment employs an eccentric wheel locking structure, ensuring angle drift of ≤±0.05° after locking, further guaranteeing measurement stability and repeatability.

[0026] In summary, the angle measuring instrument of this application embodiment achieves efficient and accurate detection of vehicle license plate angles through the integration of structural innovation and high-precision sensing technology, and is suitable for various scenarios such as vehicle inspection, testing, and traffic enforcement. In terms of data acquisition and processing, the measuring equipment involved in this application embodiment uses an embedded system for real-time data acquisition, processing, and display. Its core data comes from a high-precision digital angle sensor and an electronic level sensor 12, and is combined with an STM32F4 processor for data fusion and logical judgment. Data Source and Acquisition Method: High-precision digital angle sensor: This sensor is connected to the fitting rod 20 via a rotating shaft pin 30 and is used to detect the angle θ between the level rod 10 and the fitting rod 20. Its output is an analog voltage signal, which is converted into a digital signal by an ADC module and then input to the STM32F4 processor. Electronic level sensor 12: Based on MEMS technology, it outputs triaxial acceleration data to correct the overall attitude of the equipment and ensure the accuracy of the measurement reference. Data Format and Preprocessing Steps: Data Format: All sensor output data is stored in 16-bit signed integer form, representing angle values ​​or acceleration components. Data cleaning: The raw data is filtered using a low-pass filter (cutoff frequency of 5Hz) to remove high-frequency noise and prevent misreading caused by external vibrations. Normalization: Angle data is normalized to the range of 0° to 360°, and gravity compensation is applied to acceleration data to eliminate the influence of gravity. Dimensionality reduction: Multi-source data (angle and acceleration) are fused using a Kalman filter algorithm to improve measurement stability and reliability. These preprocessing steps effectively improve data quality, providing a reliable basis for subsequent angle calculations and compliance assessments.

[0027] The digital measurement architecture of this application embodiment can adopt an embedded system architecture, consisting of a hardware layer, a data processing layer, and an application layer, realizing a complete process from data acquisition to result display. The hardware layer includes a high-precision digital angle sensor 30: model ADXL345, supporting I... 2 The device uses the C communication protocol and has a measurement accuracy of ±0.1° with a response time of ≤0.5 seconds. The electronic level sensor 12 uses an MPU6050 module, integrating a three-axis accelerometer and gyroscope, and supports the SPI communication protocol. The OLED LCD display 40 uses an SSD1306 driver chip, with a resolution of 128×64 pixels and supports RGB three-color backlight control. The STM32F4 processor has a main frequency of 180MHz and integrates ADC, DAC, timer, and I / O. 2The system uses a C / SPI interface and supports real-time operating system (RTOS) operation. The data processing layer includes a data acquisition module responsible for acquiring raw data from various sensors and performing preliminary filtering and normalization. A data fusion module uses a Kalman filter algorithm to fuse angle and attitude data, improving measurement accuracy. A logic judgment module sets thresholds according to the GA36-2018 standard (longitudinal angle ≤15°, motorcycle ≤30°) to judge the compliance of measurement results. The application layer user interaction module displays the current angle θ, calculated angle φ, three-color backlight prompts, and a dynamic comparison bar in real time on an OLED screen. The data storage module supports storing 1000 sets of timestamped measurement data, using Flash memory for non-volatile storage. The communication module supports Bluetooth or Wi-Fi communication for easy data upload to the backend management system. This system architecture is rationally designed, with all modules working collaboratively to achieve efficient and accurate measurement functions.

[0028] The core algorithm of this application embodiment includes angle calculation, data fusion, and compliance judgment. Let θ be the included angle between the horizontal ruler 10 and the fitting rod 20, and its calculation formula is as follows:

[0029]

[0030] Among them, a x Let g be the acceleration component of the electronic level sensor 12 in the X-axis direction, and g be the acceleration due to gravity (9.8 m / s²). 2 This formula, based on the principle of gravity vector projection, is used to calculate the tilt angle of the device relative to the horizontal plane. Kalman filtering is used to fuse data from the high-precision digital angle sensor 30 and the electronic level sensor 12; its state equation is as follows:

[0031] x k =Ax k-1 +Bu k +w k

[0032] z k =Hx k +v k

[0033] Where: x k A is the state vector, containing the current angle and prediction error; B is the state transition matrix; C is the control input matrix; D is the state vector. k For control input; w k For process noise; z k V represents the observed values; H represents the observation matrix; v kTo reduce noise, Kalman filtering effectively reduces noise interference and improves the stability and accuracy of angle measurements through iterative updates. According to the GA36-2018 standard, the threshold judgment logic is set as follows: - If θ ≤ 15 degrees, it is judged as "compliant" (green light prompt); 15 degrees < θ ≤ 30 degrees, it is judged as "critical" (yellow light prompt); if θ > 30 degrees, it is judged as "exceeding the standard" (red light prompt). This logic is implemented through conditional statements in the STM32F4 processor, which has high execution efficiency.

[0034] The specific implementation of this application embodiment is as follows: 1. Device initialization: After starting the device, the STM32F4 processor automatically initializes each sensor module and completes self-test and calibration. 2. Bonding operation: According to the surface characteristics of the license plate being tested, a flexible curve forming rod or a magnetic suction rod is selected for bonding. If it is a curved surface structure, a flexible curve forming rod is used, and its anti-slip rubber layer (friction coefficient ≥0.8) at the contact end ensures stable bonding; if it is a metal surface, a magnetic suction rod is used, whose embedded permanent magnet has an adsorption force ≥5N and can penetrate a paint layer of less than 0.5mm to achieve stable adsorption. 3. Angle measurement: The bonding rod 20 and the level rod 10 are adjusted to be parallel to the plane of the license plate. At this time, the high-precision digital angle sensor at the hinge point begins to collect data. The STM32F4 processor performs data fusion processing through the Kalman filter algorithm to obtain the current included angle θ. 4. Horizontal calibration: The electronic level sensor 12 detects the overall posture of the device. If there is a tilt, the mechanical bubble level 11 is used to assist in correction to ensure accurate measurement benchmark. 5. Result Display: The OLED LCD screen (display unit 40) displays the current included angle θ, calculated angle φ, three-color backlight prompts, and dynamic comparison bars in real time, intuitively reflecting whether the measurement results meet the GA36-2018 standard. 6. Data Storage: After each measurement, the system automatically records the current timestamp and measurement result, and stores them in the Flash memory, which can store up to 1000 sets of data. 7. Locking and Reset: To maintain the current measurement angle, it can be locked using the eccentric wheel locking structure of the angle locking mechanism. After locking, the angle drift is ≤±0.05°, ensuring consistency in repeated measurements. In this embodiment, a Bluetooth or Wi-Fi module can be added to the device to achieve remote transmission and cloud storage of measurement data, suitable for large-scale vehicle inspection scenarios. This embodiment can independently encapsulate each functional module (such as sensors, processors, and display modules) for easy maintenance and upgrades.

[0035] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A motor vehicle license plate angle measuring instrument, characterized in that, The angle measuring instrument includes a horizontal ruler and a bonding rod, each hinged at one end. The horizontal ruler has a built-in level to determine the horizontal reference plane. The bonding rod is a curved forming rod or a magnetic rod, with a deformable bonding layer or magnetic material at its contact end to tightly adhere to the license plate plane. A digital angle sensor and a display unit are installed at the hinge point between the horizontal ruler and the bonding rod. The angle sensor and the display unit are electrically connected, and the display unit can display the included angle data measured by the digital angle sensor in real time.

2. The angle measuring instrument according to claim 1, characterized in that, The curve shaping rod includes a multi-segment rod structure, each segment of which is provided with size scale information. The multi-segment rod structure is movably connected to form a ruler-shaped structure.

3. The angle measuring instrument according to claim 2, characterized in that, The contact end of the curved forming rod is made of a flexible material, and at least one surface of the curved forming rod is covered with an anti-slip rubber layer.

4. The angle measuring instrument according to claim 1, characterized in that, The contact end of the magnetic rod has a permanent magnet embedded in it.

5. The angle measuring instrument according to claim 1, characterized in that, Both the leveling rod and the fitting rod are made of aluminum alloy, and the surface of the aluminum alloy has been anodized.

6. The angle measuring instrument according to claim 5, characterized in that, The length of both the horizontal ruler and the fitting rod is 200mm to 300mm, and their overall weight is less than or equal to 500g.

7. The angle measuring instrument according to claim 1, characterized in that, The angle measuring instrument also includes an angle locking mechanism, which can fix the relative position between the horizontal ruler and the fitting rod during the measurement process.

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