Winding angle deviation detection and correction method and system for thermal sensor

Abstract

The invention relates to a winding angle deviation detection and correction method and system for a thermal sensor, and belongs to the technical field of thermal sensor production and detection.The method comprises the steps that S1, a winding image of a capillary tube in the winding process is obtained; s2, selecting an interested area of the winding image, wherein the interested area is an area where a capillary tube and a wire guide needle are located; s3, identifying a winding angle formed by winding each winding wire on the capillary tube in the region of interest; s4, whether deviation exists in the winding angle or not is judged, and if deviation exists in the winding angle, the deviation angle of a wire guide needle for conveying a wire is adjusted so that the winding angle can be changed; and if the winding angle has no deviation, continuously detecting until the winding of the capillary tube is finished, thereby obtaining the thermal sensor. According to the invention, whether the winding angle of the capillary tube has deviation or not can be effectively detected, the deviation is adjusted, and the yield of the thermal sensor can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal sensor production and detection, and in particular to a method and system for detecting and correcting winding angle deviation of thermal sensors. Background Art

[0002] Thermal sensors are widely used in industry and scientific research. Their performance and accuracy directly affect the accuracy and reliability of the measurement results. Winding is one of the key steps in the manufacturing process of thermal sensors. The quality and accuracy of winding are directly related to the performance of the sensor. During the winding process, the angular deviation of each winding wire on the capillary is a common problem, which will cause the performance of the sensor to deteriorate or even fail to work properly.

[0003] In order to prevent the thermal sensor from angular deviation during the winding process, the traditional manual adjustment method relies on the operator's experience, which is inefficient and difficult to ensure accuracy. With the development of industrial automation and machine vision, image-based adaptive control is widely used, and modern means are needed to solve the angular deviation problem of thermal sensors during the winding process. Summary of the invention

[0004] To this end, the technical problem to be solved by the present invention is to overcome the problem in the prior art that manually judging whether a thermal sensor generates an angle deviation during the winding process is inefficient and difficult to ensure accuracy.

[0005] In order to solve the above technical problems, the present invention provides a method for detecting and correcting winding angle deviation of a thermal sensor, comprising: Step S1: acquiring a winding image of the capillary during the winding process; Step S2: selecting a region of interest of the winding image, wherein the region of interest is the region where the capillary and the guide wire needle of the guide wire are located; Step S3: identifying the winding angle formed by each winding wire in the region of interest when it is wound on the capillary; Step S4: Determine whether there is a deviation in the winding angle. If there is a deviation in the winding angle, adjust the offset angle of the wire needle of the conveying wire to change the winding angle; if there is no deviation in the winding angle, continue to detect until the capillary winding is completed to obtain a thermal sensor.

[0006] In one embodiment of the present invention, the method of selecting the region of interest of the winding image in step S2 comprises: Assume the coordinate area of ​​the winding image is , , , , is the coordinate value of the boundary of the winding image and satisfies and ; Define the central region of interest ROI_A in the winding image, expressed as ,satisfy ,in, is a range parameter and , is the capillary radius, is the wire diameter, , is the shortest distance from the wire needle to the capillary, is the wire needle length; The variable region ROI_B is divided from the central region of interest ROI_A, and the variable region ROI_B is used as the region of interest, which is expressed as , where the horizontal position of the wire needle is , and its horizontal movement range is ; When the guide needle moves horizontally, the horizontal coordinate of the variable area ROI_B moves accordingly and satisfies the expression , ,in, For the wire needle The horizontal displacement at the moment, , are the initial horizontal coordinates of the variable region ROI_B, and satisfy .

[0007] In one embodiment of the present invention, the variable region ROI_B is optimized, and the method includes: The horizontal length of the variable region ROI_B is optimized to prevent and The interval between them is greater than the first length or less than the second length, and the formula is: ,in, is the horizontal length of the optimized variable region ROI_B, is the maximum horizontal motion range of the guide needle and , is the recognition time of unit image area; is the adjustment factor.

[0008] In one embodiment of the present invention, the adjustment coefficient satisfy: .

[0009] In one embodiment of the present invention, the method of identifying the winding angle formed by each winding wire in the region of interest wound on the capillary in step S3 includes: Perform grayscale processing on the image corresponding to the region of interest to obtain a grayscale image; The grayscale image is smoothed by Gaussian filtering to reduce noise interference; Binarize the image after Gaussian filtering to obtain a binary image; The region ROI_C containing the wire needle in the binary image is intercepted and expressed as ,in, ; Perform Hough line detection on the intercepted area ROI_C and record the length of the line; Select the two longest straight lines, corresponding to the left and right sides of the wire outlet of the wire needle, and define them as the left and right edges of the wire needle; Suppose the sum of the angles between the left and right edges of the wire needle is , select a straight line with the same ordinate and the largest abscissa from the left and right edges of the conductor needle, which corresponds to the right straight line of the conductor needle outlet for the conductor to be used for outlet, and is defined as ,exist Take two points and ,in, like , , then the angle between the right edge of the wire needle and the horizontal direction is , the angle between the conductor at the conductor pin outlet and the horizontal direction is ; like , , then the angle between the right edge of the wire needle and the horizontal direction is , the angle between the conductor at the conductor pin outlet and the horizontal direction is ; The angle between the wire at the wire needle outlet and the horizontal direction is used as the winding angle formed by each winding wire on the capillary.

[0010] In one embodiment of the present invention, if there is a deviation in the winding angle in step S4, the method of adjusting the offset angle of the guidewire needle of the conveying guidewire to change the winding angle includes: If there is a deviation in the winding angle, the PWM signal frequency of the motor connected to the wire needle is adjusted, thereby changing the horizontal movement direction of the wire needle to correct the winding angle.

[0011] In one embodiment of the present invention, the method for adjusting the PWM signal frequency of the motor connected to the wire needle includes: A correction model based on angle deviation is constructed, and the PWM signal frequency of the motor is adjusted by the correction model. The correction model formula is: ; in, is the frequency of the motor's PWM signal; is the currently measured angle deviation; for exist The frequency of the PWM signal corresponding to the ideal state; is the sensitivity parameter and .

[0012] In order to solve the above technical problems, the present invention provides a winding angle deviation detection and correction system for a thermal sensor, using the above winding angle deviation detection and correction method for a thermal sensor, comprising: Acquisition module: used to acquire the winding image of the capillary during the winding process; A selection module: used for selecting a region of interest of the winding image, wherein the region of interest is a region where the capillary and the guide wire needle of the conveying guide wire are located; An identification module is used to identify the winding angle formed by each winding wire on the capillary in the region of interest; Judgment and correction module: used to judge whether there is a deviation in the winding angle. If there is a deviation in the winding angle, the offset angle of the wire needle of the conveying wire is adjusted to change the winding angle; if there is no deviation in the winding angle, the detection is continued until the capillary winding is completed to obtain a thermal sensor.

[0013] In order to solve the above technical problems, the present invention provides a thermal sensor winding detection device, including a memory, a processor and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, the steps of the winding angle deviation detection and correction method for thermal sensors as described above are implemented.

[0014] In order to solve the above technical problems, the present invention provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned winding angle deviation detection and correction method for thermal sensors are implemented.

[0015] The above technical solution of the present invention has the following advantages compared with the prior art:

[0016] The winding angle deviation detection and correction method for thermal sensors of the present invention can detect whether the winding angle is offset during the winding process, and can also perform adaptive correction if the winding angle is offset, thereby ensuring that the winding quality can meet industrial production requirements;

[0017] The present invention extracts a region of interest from a winding image, and obtains a region of interest with the smallest area. This processing method can not only quickly locate the positions of the capillary and the guide needle, but also accelerate the calculation time to meet the real-time detection requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0019] Figure 1 is a flow chart of the method of the present invention;

[0020] Figure 2 It is a schematic diagram of the positions of the central region of interest ROI_A, the variable region ROI_B, and the intercepted region ROI_C according to an embodiment of the present invention;

[0021] Figure 3 is a schematic diagram of a guide wire needle according to an embodiment of the present invention;

[0022] Figure 4 It is a schematic diagram of two points on the right edge of the wire outlet of the wire needle in the embodiment of the present invention;

[0023] Figure 5 It is a schematic diagram of the angle between the wire needle and the horizontal direction in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0025] Embodiment 1

[0026] Reference Figure 1 As shown, the present invention relates to a winding angle deviation detection and correction method for a thermal sensor, comprising: Step S1: obtaining a winding image of the capillary during the winding process, wherein the capillary winding is completed to obtain a thermal sensor; Step S2: selecting a region of interest of the winding image, wherein the region of interest is the region where the capillary and the guide wire needle of the guide wire are located; Step S3: identifying the winding angle formed by each winding wire in the region of interest when it is wound on the capillary; Step S4: Determine whether there is a deviation in the winding angle. If there is a deviation in the winding angle, adjust the offset angle of the wire needle of the conveying wire to change the winding angle; if there is no deviation in the winding angle, continue to detect until the capillary winding is completed to obtain a thermal sensor.

[0027] The following is a detailed description of this embodiment: In the detection process, in order to effectively reduce the amount of calculation and reasoning time, this embodiment provides a ROI (region of interest) selection method, please refer to Figure 2 , select a part of the area of ​​the captured winding image for recognition, specifically including the following steps: (1) Assume that the coordinate region of the winding image is , , , , is the coordinate value of the boundary of the winding image, satisfying and ; (2) Define the central region of interest ROI_A in the winding image, expressed as ,satisfy ,in, is a range parameter and Available, is the capillary radius, is the wire diameter, , is the shortest distance from the wire needle to the capillary, is the wire needle length; (3) The central region of interest ROI_A is further divided into a variable region ROI_B, and the variable region ROI_B is taken as the region of interest, which is expressed as , where the horizontal position of the wire needle is , , and its horizontal movement range is ; When the wire needle moves horizontally (the wire outlet direction of the wire needle is normally perpendicular to the radial direction of the capillary), the horizontal coordinate of the variable area ROI_B moves accordingly and satisfies the following expression: ; ; When the wire needle moves in the positive direction of the x-axis, , when the wire needle moves in the negative direction of the x-axis, subtract ; is the horizontal displacement of the wire needle, , are the initial horizontal coordinates of the variable region ROI_B, satisfying .

[0028] Furthermore, this embodiment also optimizes the variable region ROI_B, specifically as follows: , When the interval is too large (greater than the first length), the variable area ROI_B to be identified each time is too large, which will increase the amount of calculation and reasoning time; , When the interval is too small (less than the second length), the number of identifications required will increase. For example, if the initial variable region ROI_B is only 1 / 2 the length of the current ROI_B, then identifying the current variable region ROI_B is equivalent to identifying the initial variable region ROI_B three times), that is, the variable region ROI_B is identified by multiple identifications.

[0029] In view of this, this embodiment constructs a region length optimization formula for the variable region ROI_B: ; in, is the length of the optimized variable region ROI_B in the horizontal direction (i.e., x direction), is the maximum horizontal motion range of the guide needle and , that is, the total length of the current winding range; is the recognition time of a unit image area (each image area is composed of several unit image areas); is the adjustment factor and .

[0030] This embodiment also identifies the winding angle, and the method includes: (1) Perform grayscale processing on the image corresponding to the region of interest (i.e., the image corresponding to the variable region ROI_B) to obtain a grayscale image to reduce the amount of processed data; (2) Smoothing the grayscale image through Gaussian filtering to reduce noise interference caused by dust or reflection; (3) The maximum inter-class variance method (OTSU) is used to binarize the Gaussian filtered image to obtain a binary image; (4) Since the positions of the camera and the wire needle used to shoot the winding image are relatively fixed, the wire needle is fixed in the lower area of ​​the binary image. The area ROI_C containing the wire needle below the entire binary image is captured. ,in, ; (5) Perform Hough line detection on the intercepted area ROI_C and record the lengths of all lines (i.e., identify the edges of the lines on the left and right sides of the guide needle); (6) Select the two longest straight lines, corresponding to the left and right sides of the wire outlet of the wire needle, and define them as the left and right edges of the wire needle; Please note that Figure 3The wire needle is usually triangular in shape, and the wire outlet of the wire needle is an acute angle. Ideally, the wire passing through the outlet is usually perpendicular to the capillary. In short, in theory, the angle between each winding wire on the capillary and the capillary should be 90 degrees; (7) In this embodiment, the sum of the angles between the left and right edges of the guide pin is , select a straight line with the same ordinate and the largest abscissa from the left and right edges of the conductor needle, which corresponds to the right straight line of the conductor needle outlet for the conductor to be used for outlet, and is defined as ,exist Take two points and , see Figure 4 and Figure 5 ,in, like , , then the angle between the right edge of the wire needle and the horizontal direction (i.e. the radial direction of the capillary) is , the angle between the wire at the wire needle outlet and the horizontal direction (i.e. the radial direction of the capillary) is ; like , , then the angle between the right edge of the wire needle and the horizontal direction (i.e. the radial direction of the capillary) is , the angle between the wire at the wire needle outlet and the horizontal direction (i.e. the radial direction of the capillary) is .

[0031] It should be noted that when the angle of the wire needle is offset, the angle of the wire output by the wire needle will also change, that is, Changes, in theory for , at the current moment in the winding process, as long as Not for , it means that there is a deviation in the current winding angle on the capillary.

[0032] In this embodiment, the angle between the wire at the wire needle outlet and the horizontal direction is used as the winding angle formed by each winding wire on the capillary. If the angle between the wire at the wire needle outlet and the horizontal direction changes, the winding angle formed by each winding wire on the capillary will inevitably change.

[0033] The reason why the region of interest of the winding image is extracted in this embodiment is that the position of the capillary can be quickly located and the calculation time can be accelerated to meet the real-time detection requirements.

[0034] It is worth mentioning that when there is a deviation in the winding angle in step S4, the offset angle of the wire needle of the conveying wire is adjusted, including: if there is a deviation in the winding angle, the PWM signal frequency of the motor connected to the wire needle is adjusted, thereby changing the horizontal movement direction of the wire needle to correct the winding angle.

[0035] Specifically, this embodiment constructs a method based on angle deviation correction. If there is a deviation in the winding angle in step S4, the PWM signal frequency of the motor is adjusted. By constructing a correction model based on angle deviation, the correction model is used to adjust the PWM signal frequency of the motor, thereby changing the horizontal movement direction of the wire needle to complete the angle deviation correction.

[0036] The correction model formula of this embodiment is: ; in, is the frequency of the motor's PWM signal; is the currently measured angle deviation value; for exist The frequency of the PWM signal corresponding to the ideal state is preset as the frequency threshold of the motor control system; is the sensitivity parameter and , which can be adjusted according to the actual motor characteristics.

[0037] Embodiment 2

[0038] This embodiment provides a winding angle deviation detection and correction system for a thermal sensor, using the winding angle deviation detection and correction method for a thermal sensor described in Embodiment 1, including: Acquisition module: used to acquire the winding image of the capillary during the winding process; A selection module: used for selecting a region of interest of the winding image, wherein the region of interest is a region where the capillary and the guide wire needle of the conveying guide wire are located; An identification module is used to identify the winding angle formed by each winding wire on the capillary in the region of interest; Judgment and correction module: used to judge whether there is a deviation in the winding angle. If there is a deviation in the winding angle, the offset angle of the wire needle of the conveying wire is adjusted to change the winding angle; if there is no deviation in the winding angle, the detection is continued until the capillary winding is completed to obtain a thermal sensor.

[0039] Embodiment 3

[0040] The present embodiment provides a thermal sensor winding detection device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the winding angle deviation detection and correction method for the thermal sensor described in the first embodiment are implemented.

[0041] Embodiment 4

[0042] This embodiment provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the winding angle deviation detection and correction method for a thermal sensor described in the first embodiment are implemented.

[0043] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present application may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0044] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0045] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0046] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0047] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0048] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A method for detecting and correcting winding angle deviation of a thermal sensor, characterized in that: include: Step S1: acquiring a winding image of the capillary during the winding process; Step S2: selecting a region of interest of the winding image, wherein the region of interest is the region where the capillary and the guide wire needle of the guide wire are located; Step S3: identifying the winding angle formed by each winding wire in the region of interest when it is wound on the capillary; Step S4: Determine whether there is a deviation in the winding angle. If there is a deviation in the winding angle, adjust the offset angle of the wire needle of the conveying wire to change the winding angle; if there is no deviation in the winding angle, continue to detect until the capillary winding is completed to obtain a thermal sensor.

2. The method for detecting and correcting winding angle deviation of a thermal sensor according to claim 1, characterized in that: The method for selecting the region of interest of the winding image in step S2 comprises: Assume the coordinate area of ​​the winding image is , , , , is the coordinate value of the boundary of the winding image and satisfies and ; Define the central region of interest ROI_A in the winding image, expressed as ,satisfy ,in, is a range parameter and , is the capillary radius, is the wire diameter, , is the shortest distance from the wire needle to the capillary, is the length of the wire needle; The variable region ROI_B is divided from the central region of interest ROI_A, and the variable region ROI_B is used as the region of interest, which is expressed as , where the horizontal position of the wire needle is , and its horizontal movement range is ; When the guide needle moves horizontally, the horizontal coordinate of the variable area ROI_B moves accordingly and satisfies the expression , ,in, For the wire needle The horizontal displacement at the moment, , are the initial horizontal coordinates of the variable region ROI_B, and satisfy .

3. The method for detecting and correcting winding angle deviation of a thermal sensor according to claim 2, characterized in that: The variable region ROI_B is optimized, and the method includes: The horizontal length of the variable region ROI_B is optimized to prevent and The interval between them is greater than the first length or less than the second length, and the formula is: ,in, is the horizontal length of the optimized variable region ROI_B, is the maximum horizontal motion range of the guide needle and , is the recognition time of unit image area; is the adjustment factor.

4. The method for detecting and correcting winding angle deviation of a thermal sensor according to claim 3, characterized in that: The adjustment factor satisfy: 。 5. The method for detecting and correcting winding angle deviation of a thermal sensor according to claim 2, characterized in that: The method for identifying the winding angle formed by each winding wire in the region of interest wound on the capillary in step S3 includes: Perform grayscale processing on the image corresponding to the region of interest to obtain a grayscale image; The grayscale image is smoothed by Gaussian filtering to reduce noise interference; Binarize the image after Gaussian filtering to obtain a binary image; The region ROI_C containing the wire needle in the binary image is intercepted and expressed as ,in, ; Perform Hough line detection on the intercepted area ROI_C and record the length of the line; Select the two longest straight lines, corresponding to the left and right sides of the wire outlet of the wire needle, and define them as the left and right edges of the wire needle; Suppose the sum of the angles between the left and right edges of the wire needle is , select a straight line with the same ordinate and the largest abscissa from the left and right edges of the conductor needle, which corresponds to the right straight line of the conductor needle outlet for the conductor to be used for outlet, and is defined as ,exist Take two points and ,in, like , , then the angle between the right edge of the wire needle and the horizontal direction is , the angle between the conductor at the conductor pin outlet and the horizontal direction is ; like , , then the angle between the right edge of the wire needle and the horizontal direction is , the angle between the conductor at the conductor pin outlet and the horizontal direction is ; The angle between the wire at the wire needle outlet and the horizontal direction is used as the winding angle formed by each winding wire on the capillary.

6. The method for detecting and correcting winding angle deviation of a thermal sensor according to claim 1, characterized in that: If there is a deviation in the winding angle in step S4, the method of adjusting the deviation angle of the guide wire needle of the conveying guide wire to change the winding angle includes: If there is a deviation in the winding angle, the PWM signal frequency of the motor connected to the wire needle is adjusted, thereby changing the horizontal movement direction of the wire needle to correct the winding angle.

7. The method for detecting and correcting winding angle deviation of a thermal sensor according to claim 6, characterized in that: The method for adjusting the PWM signal frequency of the motor connected to the wire needle includes: A correction model based on angle deviation is constructed, and the PWM signal frequency of the motor is adjusted by the correction model. The correction model formula is: ； in, is the frequency of the motor's PWM signal; is the currently measured angle deviation; for exist The frequency of the PWM signal corresponding to the ideal state; is the sensitivity parameter and .

8. A winding angle deviation detection and correction system for a thermal sensor, using the winding angle deviation detection and correction method for a thermal sensor as claimed in claim 1, characterized in that: include: Acquisition module: used to acquire the winding image of the capillary during the winding process; A selection module: used for selecting a region of interest of the winding image, wherein the region of interest is a region where the capillary and the guide wire needle of the conveying guide wire are located; An identification module is used to identify the winding angle formed by each winding wire on the capillary in the region of interest; Judgment and correction module: used to judge whether there is a deviation in the winding angle. If there is a deviation in the winding angle, the offset angle of the wire needle of the conveying wire is adjusted to change the winding angle; if there is no deviation in the winding angle, the detection is continued until the capillary winding is completed to obtain a thermal sensor.

9. A thermal sensor winding detection device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the winding angle deviation detection and correction method for a thermal sensor as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the winding angle deviation detection and correction method for a thermal sensor as claimed in any one of claims 1 to 7 are implemented.

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