Vehicle VIN code character size measurement method and device

Abstract

The invention provides a vehicle VIN code character size measurement method and device, and relates to the technical field of size measurement. The method comprises the steps that three-dimensional contour sequence data of VIN code characters of a vehicle are scanned and collected in real time, and a character contour data sequence is obtained through recognition; extracting starting position information and ending position information of character data points in the current character contour data sequence to obtain height information; the scanning count value and the scanning precision of the character contour are obtained in real time, and width information is obtained; and continuously acquiring three-dimensional contour sequence data and scanning count values along the scanning direction, continuously updating height information and width information, and outputting the character size of each character. The problems that an existing measurement method is low in measurement precision and efficiency and cannot be applied to an automatic production line in a large scale are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of dimension measurement, and particularly to a method and device for measuring the dimensions of vehicle VIN code characters. Background Art

[0002] The vehicle VIN code (Vehicle Identification Number, also known as the frame number) is the unique identification information of a vehicle, which contains many important information such as the vehicle manufacturer, production year, vehicle model, body type and code, engine code, and assembly location, etc.; the dimensions of VIN code characters include the character width and character height of each character, which is one of the important indicators for inspecting whether the VIN code is qualified.

[0003] Currently, the measurement of vehicle VIN code character dimensions is obtained by processing two-dimensional images based on image processing technology; or first converting three-dimensional point cloud data into a two-dimensional image, and then using image processing technology to segment and measure the two-dimensional image, and finally obtaining the width and height of the vehicle VIN code characters. However, due to the data type conversion process in this measurement method, on the one hand, it will cause data precision loss and cannot guarantee the measurement precision; on the other hand, the measurement method based on image processing technology needs to wait for the VIN code data scanning to be completed before data conversion and measurement calculation can be performed, which will lead to long data analysis time and low overall measurement efficiency. It is difficult to ensure precision, speed, and stability in automated measurement, restricting large-scale applications in automated production lines. Summary of the Invention

[0004] Based on this, it is necessary to provide a method and device for measuring the dimensions of vehicle VIN code characters to solve the problems of low measurement precision, low efficiency, and inability to be widely applied in automated production lines in the existing measurement methods.

[0005] In a first aspect, the present invention provides a method for measuring the dimensions of vehicle VIN code characters, the method comprising: Real-time scanning and collecting three-dimensional contour sequence data of vehicle VIN code characters, and identifying to obtain a character contour data sequence; Extracting the start position information and end position information of character data points in the current character contour data sequence to obtain height information; Real-time obtaining the scan count value and scan precision of the character contour to obtain width information; Continuously obtaining the three-dimensional contour sequence data and the scan count value along the scan direction, continuously updating the height information and width information, and outputting the character dimensions of each character.

[0006] Further, obtaining the height information includes: comparing the starting position points and ending position points of all character data points in the current character contour data sequence to obtain the highest starting position information and the lowest ending position information; calculating the difference between the highest starting position information and the lowest ending position information to obtain the height information.

[0007] Further, the calculation formula for the height information is: ; Where, represents the height information obtained from the th extraction of position information; represents the starting position information extracted for the th time; represents the ending position information extracted for the th time; represents the position sequence set of the character contour data sequence extracted for the th time; represents the highest starting position information in the position sequence set; represents the lowest ending position information in the position sequence set.

[0008] Further, the calculation methods for the highest starting position information and the lowest starting position information are: Sort the position sequence set to obtain the position information set ; Set the counting threshold and the position difference threshold , and traverse the position information set from the beginning; When the position difference between two consecutive position information in the position information set is less than , and the consecutive count is not less than , the first position information that meets this condition is recorded as the lowest ending position, and the last position information that meets this condition is recorded as the highest starting position.

[0009] Further, the width information is the product of the scan count value and the scan accuracy.

[0010] Further, the calculation method for the width information is: ; Where, represents the width information obtained when extracting the character contour data for the th time; represents the scan count value; represents the scan accuracy, , represents the moving speed along the scan direction, Indicates the scanning frequency.

[0011] Furthermore, the method for obtaining the scanning count value of the character contour is as follows: when the character contour data is recognized, the scanning count value is incremented by one, and continuous scanning is performed along the scanning direction until the base material contour data is recognized, indicating that the character scanning is completed, and the scanning count value is obtained.

[0012] Furthermore, the method for recognizing the character contour data sequence is as follows: by calculating the residual value between two adjacent data points on the contour data to identify whether it is character contour data; if there is a residual value greater than or equal to the preset minimum character depth value, the current contour data is character contour data and is included in the character contour data sequence, otherwise it is base material contour data.

[0013] Furthermore, the residual value is calculated as follows: ; wherein, represents the depth value of the th data point; represents the depth value of the th data point.

[0014] In a second aspect, the present invention provides a vehicle VIN code character size measuring device, including a memory, a processor, and a computer program stored on the memory, and the processor executes the computer program to implement the steps of the method described in any one of the above.

[0015] Generally speaking, the present invention provides a vehicle VIN code character size measuring method and device, which can achieve the following beneficial effects compared with the prior art: (1) While the present invention collects three-dimensional contour sequence data in real time, it quickly recognizes the character contour data sequence and statistically analyzes the position information of the character data points in the character contour data sequence, and then calculates the height and width of each character. On the one hand, it avoids converting the three-dimensional contour sequence data into a two-dimensional image, and the whole process does not involve data type conversion, so there will be no loss of data accuracy, effectively improving the measurement accuracy and efficiency; on the other hand, it does not need to wait until all data scanning and collection are completed before performing data analysis and processing, but outputs the measurement results while collecting data, and the character size results of the measurement are output at the same time as the data collection is completed, effectively improving the data processing speed.

[0016] (2) The present invention is applicable to all 3D profiler character detection systems and can be easily integrated into various character detection systems without adding other additional hardware or actions. It has high integration, a fast and accurate measurement process, and features such as high measurement accuracy, fast measurement efficiency, high automation, and simple integration. To a great extent, it improves the accuracy and efficiency of the automatic measurement of vehicle VIN code character sizes, which is conducive to the large-scale application of vehicle VIN code detection on the automatic production line.

[0017] (3) The residual method proposed by the present invention for identifying character contours and base material contours can quickly and accurately segment different characters, accurately locate the character data points in the character contours, and then achieve the accurate measurement of the width and height of each character, improving the measurement accuracy and efficiency. Brief Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a schematic flowchart of the method for measuring vehicle VIN code character sizes and the device provided by the present invention; Figure 2 It is a schematic diagram of the character size measurement principle of the method for measuring vehicle VIN code character sizes and the device provided by the present invention; Figure 3 It is a schematic diagram of the character contour data and base material contour data of the method for measuring vehicle VIN code character sizes and the device provided by the present invention; Figure 4 It is a schematic diagram of the height calculation principle of the current character contour data of the method for measuring vehicle VIN code character sizes and the device provided by the present invention. Detailed Embodiments

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention in combination with the drawings and embodiments in the present invention. Obviously, the described embodiments are some, rather than all, of the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0021] It should be noted that in the description of the embodiments of the present invention, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a method, step or system including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or elements inherent to such method, step or system. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the method, step or system including the said element.

[0022] In order to achieve automatic high-precision measurement of the width and height of vehicle VIN code characters, the present invention proposes a method for measuring the size of vehicle VIN code characters. While acquiring and analyzing the three-dimensional contour sequence data of vehicle VIN code characters in real time, this method can quickly identify character contour data and base material contour data, extract the position information of character data points in the character contour data and the scan count value of the character contour, and then calculate the width size and height size of each character. While completing data scanning, it synchronously realizes different character segmentation and character size measurement, featuring high measurement accuracy, fast measurement efficiency and high automation.

[0023] Specifically, as Figure 1 shown, the method includes: Step 101: Scan and collect the three-dimensional contour sequence data of vehicle VIN code characters in real time, and identify the character contour data sequence.

[0024] As Figure 2 shown, longitudinally scan the vehicle VIN code characters multiple times in real time along the transverse scanning direction to collect the three-dimensional contour sequence data , obtain the character contour data of each scan , and judge whether the contour data is character contour data or base material contour data. Only when the contour data is character contour data will it be included in the character contour data sequence. and are positive integers, representing the number of scans.

[0025] For example, continuously scan 50 times along the scanning direction. When scanning for the 10th time, identify the contour data as character contour data, and continue scanning until when scanning for the 40th time, identify the contour data as base material contour data. Then, the identified character contour data sequence will be successively included in the character contour data sequence to obtain the character contour data sequence .

[0026] Successively include the identified character contour data to obtain the character contour data sequence , so as to achieve the segmentation between different character contours without converting the three-dimensional contour sequence data into a two-dimensional image and then using image processing, effectively improving the measurement accuracy and efficiency.

[0027] It should be noted that, as Figure 3 shown, there are obvious differences between the character contour data and the base material contour data. As an embodiment, the method for identifying the character contour data sequence is as follows: Identify whether the contour data is character contour data by calculating the residual value between two adjacent data points on the contour data; if there is a residual value greater than or equal to the preset minimum character depth value, the current contour data is character contour data and is included in the character contour data sequence, otherwise it is base material contour data.

[0028] Furthermore, the calculation method of the residual value is: ; wherein, represents the depth value of the th data point; represents the depth value of the th data point.

[0029] For example, the preset minimum character depth value is , if , it means that there is a depth difference between two adjacent data points, and a stamped character is scanned, and this contour data is character contour data, as Figure 3 shown in (a); conversely, if , it means that there is no depth difference between two adjacent data points, and no stamped character is scanned, and this contour data is base material contour data, as Figure 3 shown in (b).

[0030] Step 102: Extract the start position information and end position information of the character data points in the character contour data sequence to obtain the height information.

[0031] That is to say, when the character contour data is identified, the start position and end position of the character data points in the current character contour data sequence are synchronously extracted. As Figure 4 shown, for the th extraction of the start position and end position of the character data points in the character contour data sequence, the height of the current character contour data is: .

[0032] As an example, obtaining the height information includes: comparing the starting position points and ending position points of all character data points in the current character contour data sequence to obtain the highest starting position information and the lowest ending position information; calculating the difference between the highest starting position information and the lowest ending position information to obtain the height information.

[0033] More specifically, the calculation formula for the height information is: ; Where represents the height information obtained by extracting the position information for the th time; represents the starting position information extracted for the th time; represents the ending position information extracted for the th time; represents the position sequence set of the character contour data sequence extracted for the th time; represents the highest starting position information in the position sequence set; represents the lowest ending position information in the position sequence set.

[0034] Furthermore, to minimize the influence of noise on the calculation accuracy of the character height information, the calculation methods for the highest starting position information and the lowest starting position information are as follows: Sort the position sequence set to obtain the position information set ; Set a counting threshold and a position difference threshold , and traverse the position information set from the beginning; When the position difference between two consecutive position information in the position information set is less than , and the consecutive count is not less than , the first position information that meets this condition is recorded as the lowest ending position, and the last position information that meets this condition is recorded as the highest starting position.

[0035] Step 103: Obtain the scanning count value and scanning accuracy of the character contour in real time to obtain the width information.

[0036] As an example, the width information can be the product of the scanning count value and the scanning accuracy.

[0037] Specifically, the calculation method for the width information is: ; Where represents the width information obtained when extracting the position information from the character contour data sequence for the th time; Indicates the scanning count value; Indicates the scanning accuracy, , Indicates the moving speed along the scanning direction, such as Figure 2 The y-axis direction shown, Indicates the scanning frequency, such as Figure 2 The positive or negative direction of the x-axis shown.

[0038] It should be noted that the scanning count value represents the number of times the character contour is scanned, that is, the number of character contour data obtained by recognition. In other words, the scanning count value is equal to the number of character contour data in the character contour data sequence.

[0039] Furthermore, the method for obtaining the scanning count value of the character contour is as follows: When the character contour data is obtained by recognition, the scanning count value is incremented by one, and continuously scanned along the scanning direction until the base material contour data is obtained by recognition, indicating that the character scanning is completed, and the scanning count value is obtained.

[0040] Such as Figure 2 Shown, the character contour data is obtained by scanning recognition , the character contour data sequence is , the scanning count value ; Continue scanning, and the character contour data is obtained by recognition, the character contour data sequence is , the scanning count value ; And so on, until the th time of scanning and recognition to obtain the base material contour data, which indicates that the character scanning is completed, the next one is a new character, and the scanning count value is obtained, the th time of recognition to obtain the character contour number , the character contour data sequence is , the scanning count value , is a positive integer.

[0041] Step 104: Continuously obtain the three-dimensional contour sequence data and the scanning count value along the scanning direction, continuously update the height information and width information, and output the character size of each character.

[0042] For example, the character contour data is obtained by the first scanning recognition, then the character contour data sequence is , the starting position extracted is , the ending position is , and the height information after the first scanning is output, denoted as . At this time, the scanning count value of the character contour is and the scanning accuracy , the width information is obtained . Furthermore, the character size is output .

[0043] Continue scanning, and the character contour data is obtained through the second scan , then the character contour data sequence is , and the extracted starting positions are respectively and , and the ending positions are respectively and ; At this time, it is necessary to compare the two starting position points and the two ending position points to obtain the highest starting position information and the lowest ending position information, and thereby obtain the distance difference between the two, which is also the height information after the second scan, denoted as .

[0044] If the starting position point is the same as the starting position point , and the ending position point is lower than the ending position point , then the output height information is denoted as or ; If the starting position point is higher than the starting position point , and the ending position point is lower than the ending position point , then the output height information is denoted as . That is to say, compare the starting position points and ending position points of all character data points in the current character contour data sequence to obtain the highest starting position information and the lowest ending position information; calculate the distance difference between the highest starting position information and the lowest ending position information, and output the height information.

[0045] At this time, the scan count value of the character contour is and the scan accuracy , the width information is obtained . Furthermore, the character size is output .

[0046] In this way, the height information is continuously updated according to the highest starting position information and the lowest ending position information, and the width information is continuously updated according to the scan count value, and then the character size of the current character is output in real time.

[0047] In summary, while the present invention is collecting three-dimensional contour sequence data in real time, it quickly identifies the character contour data sequence and counts the position information of the character data points in the character contour data sequence, and then calculates the height and width of each character. On the one hand, it avoids converting the three-dimensional contour sequence data into a two-dimensional image. The whole process does not involve data type conversion and will not cause data precision loss, effectively improving the measurement accuracy and efficiency. On the other hand, it does not need to wait until all data scanning and collection are completed before performing data analysis and processing. Instead, it outputs the measurement results while collecting data. When the data collection is completed, the measurement results of the character sizes are also output, effectively improving the data processing speed.

[0048] In a second aspect, the present invention provides a vehicle VIN code character size measuring device, including a memory, a processor, and a computer program stored on the memory. The processor executes the computer program to implement the steps of the method described in any one of the above. The technical solution of the device is consistent with the technical solution of the method, and will not be elaborated here.

[0049] It should be noted that for the foregoing various embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present invention is not limited by the described action sequence. According to the present invention, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0050] In the above embodiments, the descriptions of the various embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments. In the several embodiments provided by the present invention, it should be understood that the disclosed method or system can be implemented in other ways. For example, the above-described embodiments are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0051] The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0052] In addition, in each embodiment of the present invention, each functional unit can be integrated into a processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0053] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present invention.

[0054] Those of ordinary skill in the art can understand that all or part of each circuit in the above embodiments can be completed by instructing relevant hardware through a program. This program can be stored in a computer-readable memory, and the memory can include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disc, etc.

[0055] The above are only exemplary embodiments of the present disclosure, and the scope of the present disclosure cannot be limited thereby. That is, any equivalent changes and modifications made in accordance with the teachings of the present disclosure still fall within the scope covered by the present disclosure. After considering the specification and practicing the present disclosure herein, those skilled in the art will readily think of other embodiments of the present disclosure. The present invention aims to cover any variations, uses, or adaptive changes of the present disclosure, and these variations, uses, or adaptive changes follow the general principles of the present disclosure and include common general knowledge or conventional technical means in the technical field not described in the present disclosure. The specification and embodiments are only regarded as exemplary, and the scope and spirit of the present disclosure are defined by the claims.

[0056] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. As long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0057] Those skilled in the art can easily understand that the above are only preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for measuring the character size of a vehicle VIN code, characterized in that: The method comprises: Scan and collect the three-dimensional contour sequence data of the vehicle VIN code characters in real time, and identify and obtain the character contour data sequence; Extracting the starting position information and the ending position information of the character data points in the current character outline data sequence to obtain the height information; Obtain the scanning count value and scanning accuracy of the character outline in real time to obtain width information; The three-dimensional contour sequence data and the scanning count value are continuously acquired along the scanning direction, the height information and the width information are continuously updated, and the character size of each character is output.

2. A vehicle VIN code character size measurement method according to claim 1, characterized in that: The height information is obtained by: comparing the starting position points and the ending position points of all character data points in the current character outline data sequence to obtain the highest starting position information and the lowest ending position information; calculating the difference between the highest starting position information and the lowest ending position information to obtain the height information.

3. A vehicle VIN code character size measurement method according to claim 2, characterized in that: The calculation formula of the height information is: ； in, Indicates The height information obtained by extracting the position information; Indicates The starting position information of the extraction; Indicates The end position information of the extraction; Indicates Extract the position sequence set of the character outline data sequence; Indicates the highest starting position information in the position sequence set; Indicates the lowest ending position information in a position sequence set.

4. A vehicle VIN code character size measurement method according to claim 2 or 3, characterized in that: The highest starting position information and the lowest starting position information are calculated as follows: For a set of position sequences Sort and get the location information set ; Setting the count threshold and position difference threshold , traverse the location information set from the beginning; When the position difference between two consecutive position information in the position information set is less than , and the continuous count is not less than When , the first position information that meets the condition is recorded as the lowest end position, and the last position information that meets the condition is recorded as the highest start position.

5. The method for measuring the character size of a vehicle VIN code according to claim 1, characterized in that: The width information is the product of the scan count value and the scan accuracy.

6. A vehicle VIN code character size measurement method according to claim 5, characterized in that: The width information is calculated as follows: ； in, Indicates The width information obtained when extracting the character outline data for the first time; Indicates the scan count value; Indicates the scanning accuracy. , represents the moving speed along the scanning direction, Indicates the scanning frequency.

7. A vehicle VIN code character size measurement method according to claim 5, characterized in that: The scanning count value of the character contour is obtained as follows: when the character contour data is recognized, the scanning count value is increased by one, and scanning is continuously performed along the scanning direction until the parent material contour data is recognized, indicating that the character scanning is completed and the scanning count value is obtained.

8. The method for measuring the character size of a vehicle VIN code according to claim 1, characterized in that: The method for identifying the character contour data sequence is: by calculating the residual value of two adjacent data points on the contour data to identify whether it is character contour data; if there is a residual value greater than or equal to the preset minimum character depth value, then the current contour data is character contour data and is included in the character contour data sequence, otherwise it is parent material contour data.

9. A vehicle VIN code character size measurement method according to claim 8, characterized in that: The residual value The calculation method is: ； in, Indicates The depth value of each data point; Indicates The depth value of each data point.

10. A device for measuring the character size of a vehicle VIN code, comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes a computer program to implement the steps of the method according to any one of claims 1 to 9.

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