A method for measuring the angle of a cylindrical part bevel and an angle measuring device thereof

Abstract

The invention discloses a method for measuring the bevel angle of a cylindrical part and an angle measuring device thereof. The detection method comprises: a contour map collecting step: collecting the projection contour map of the oblique section of a cylindrical element; a parameter marking step: marking the parameters of the drawn projection contour map; an angle calculation step: calculating the bevel angle of the cylindrical part by a formula; when the cylindrical element is placed horizontally along the axis, full-posture online wedge angle calculation can be realized under the conditions of axial 360° rotation and circumferential 360° rotation; the design and application of a detection system based on the algorithm can quickly and simultaneously detect multiple elements, simplify the detection steps, realize detection automation, and improve the detection efficiency; the application of the detection method does not require a special fixture to place the element for detection, thereby reducing errors caused by eccentricity of the element clamping, and coaxiality of the light source and the element; the invention provides an algorithm for detecting the bevel angle of a cylindrical element, and also provides the design of a detection system based on the algorithm.

Description

Technical Field

[0001] The invention relates to the field of detection algorithms, and in particular to a method for measuring the angle of a cylindrical part bevel and an angle measuring device thereof. Background Art

[0002] like Figure 6 As shown, the horizontally emitted laser beam irradiates a horizontally placed product with a certain polished wedge angle. The reflected beam will form an angle twice the wedge angle with the horizontal axis. According to the relationship of plane trigonometric geometry, the line deviation of the reflected beam at a fixed distance is converted into an angle. The calculation formula is L=D·tan(2α). The angle value is then marked as a group of concentric circles on the receiving screen, so that intuitive measurement results can be obtained.

[0003] Testing process:

[0004] 1. Calibrate the optical path: first replace the product with a standard 90-degree angle block, place it in the V-groove of the loading platform, adjust the knobs on the five-dimensional adjustment frame to move the reflected light spot horizontally and vertically, and finally make the horizontal and vertical movement trajectories of the reflected light spot coincide with the corresponding horizontal and vertical lines on the receiving screen, and the light beam returns along the original path;

[0005] 2. Place the component in the V-groove. The light beam should be in the center of the measured surface or completely cover the measured surface.

[0006] 3. Use tweezers to gently move the outer cylindrical surface of the component under test so that the reflected light spot is located in the middle of the receiving screen and read the value to obtain the test result.

[0007] Problems with this technique:

[0008] 1. The light beam needs to be adjusted to emit horizontally;

[0009] 2. The axis of the measured component must be coaxial with the axis of the light source, which is difficult to achieve;

[0010] 3. Clamping requires special fixtures, and the placement process is cumbersome;

[0011] 4. After the inspection, the items must be picked up one by one and then put back one by one; the inspection efficiency is low;

[0012] 5. It is difficult to achieve automation level with traditional detection methods. Summary of the invention

[0013] The object of the present invention is to overcome the above-mentioned shortcomings and provide a method for measuring the angle of the inclined surface of a cylindrical part and an angle measuring device thereof.

[0014] According to the present invention, a method for measuring the angle of a cylindrical part bevel is provided, the method comprising:

[0015] Contour map collection step: collect the oblique cross-section projection contour map of the cylindrical component;

[0016] Parameter marking step: marking the parameters of the drawn projection contour map;

[0017] Angle calculation steps: By formula: Calculate the bevel angle of cylindrical parts;

[0018] Where a' is the projection length of the short axis of the wedge angle profile projection on the projection surface when the wedge angle elliptical profile is placed vertically in the axis direction of the cylindrical element to collect the wedge angle elliptical profile;

[0019] Where b' is the projection length of the major axis of the wedge angle profile projection on the projection surface when the wedge angle elliptical profile is placed perpendicular to the axis of the cylindrical element;

[0020] Where φ is the diameter of the circular cross section of the cylinder perpendicular to the axis.

[0021] Preferably, the collection device in the contour map collection step is a CCD camera.

[0022] Preferably, the CCD camera is placed perpendicular to the axis direction of the cylindrical element to collect the elliptical contour projection image.

[0023] Preferably, the parameter marking step includes:

[0024] a, mark the minor axis of the ellipse outline as a;

[0025] b, mark the major axis of the ellipse outline as b;

[0026] c. Mark the diameter of the cylinder's vertical axis section circle as φ.

[0027] An angle measuring device for use in the above-mentioned method for measuring the angle of an inclined surface of a cylindrical part, the angle measuring device comprising:

[0028] Contour map acquisition module: collects the oblique cross-section projection contour map of cylindrical components;

[0029] Parameter marking module: mark the parameters of the drawn projection contour map;

[0030] Angle calculation module: calculate the angle of the inclined surface of cylindrical parts;

[0031] The parameter marker is connected to the angle calculation module.

[0032] Preferably, the profile map acquisition module includes:

[0033] Projection module: Project the oblique section of cylindrical components;

[0034] Receiving module: Receive and display the oblique cross-section projection contour of the cylindrical component.

[0035] Preferably, the parameter marking module includes:

[0036] Minor axis marking module: marks the minor axis of the ellipse contour;

[0037] Long axis marking module: mark the long axis of the ellipse contour;

[0038] The short axis marking module is connected to the long axis marking module.

[0039] Preferably, the angle calculation module includes:

[0040] Data collection module: collects data required for angle calculation;

[0041] Calculation processing module: Substitute the collected data into the angle calculation formula for calculation;

[0042] The data collection module is connected to the calculation processing module.

[0043] By adopting the above technical solution, the beneficial effects of the present invention are: 1. Through the algorithm of the bevel angle of the cylindrical element, when the cylindrical element is placed horizontally along the axis, full-attitude online wedge angle calculation can be achieved under the conditions of axial 360° rotation and circumferential 360° rotation.

[0044] 2. The design and application of the detection system based on this algorithm can quickly and simultaneously detect multiple components, simplify the detection steps, realize detection automation, and improve detection efficiency;

[0045] 3. The application of this measuring device does not require a special fixture to place the component for testing, which reduces the errors caused by the non-concentricity of the component clamping, the non-coaxiality of the light source and the component;

[0046] 4. The invention provides an algorithm for detecting the bevel angle of a cylindrical component, and also provides the design of a detection system based on this algorithm. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 Schematic diagram of the process of the angle measurement method of the present invention;

[0048] Figure 2 This is an axial schematic diagram of the C-Lens in Comparative Example 1 of the present invention;

[0049] Figure 3 This is a schematic diagram of the C-Lens wedge angle projection in Comparative Example 1 of the present invention;

[0050] Figure 4 Schematic diagram of wedge angle in Example 1 of the present invention;

[0051] Figure 5 This is a schematic diagram of derivation of the wedge angle function in Example 1 of the present invention;

[0052] Figure 6 It is a schematic diagram of a C-Lens angle measurement device of the prior art of the present invention;

[0053] Figure 7 It is a structural schematic diagram of the angle measuring device of the present invention;

[0054] Figure 8 This is a schematic diagram of the oblique cross-section projection structure of a cylindrical element in Example 1 of the present invention. DETAILED DESCRIPTION

[0055] The present invention is further described below with reference to the accompanying drawings and specific embodiments.

[0056] Comparative Example 1

[0057] This design uses a high-definition CCD camera to measure the geometric dimensions of the component. The algorithm derived by the present invention directly calculates the size of the bevel angle of the component being measured, and can simultaneously detect multiple components online through digital image processing technology, thereby improving production efficiency. This design greatly improves the efficiency and measurement accuracy of wedge angle measurement. The image processing technology algorithm can also be used to display the bevel angle parameters of the component being measured on the display screen; the preset error size can be used to intuitively determine whether the component being measured is qualified. The specific design of this system is as follows:

[0058] 1. Obtain the parameters a' and φ of the cylindrical component oblique section projection contour (the projection is either an ellipse or a straight line)

[0059] This algorithm needs to be used in conjunction with the CCD acquisition system. First, the axis of the cylinder to be measured is placed horizontally, and the CCD camera is used to extract the contour of the horizontal projection of the oblique section of the cylinder. The projection contour is analyzed using software to obtain the contour parameters a' and φ:

[0060] 2. Use spatial geometry and mathematical modeling methods to construct a mathematical model for wedge angle detection;

[0061] The calculation of the angle α of the oblique section of a cylindrical element is as follows: Figure 2 Shown It can be seen that by measuring a and φ, the definite value of α can be obtained. However, to directly detect the value of a, the section plane of the cylinder needs to be completely parallel to the imaging plane of the CCD camera, which is difficult to achieve. At this time, if the cylindrical component is placed horizontally along the axis with the long end at the bottom (due to gravity, most components will present this posture) and the imaging optical axis of the added CCD camera is perpendicular to the optical axis of the measured component, the section plane contour image is a deformed ellipse, such as Figure 3 Wedge angle: At this time, it is easy to measure a' and φ. Substitute The oblique section angle α of the cylindrical element can be directly calculated.

[0062] However, the placement of the cylindrical element requires a special calculation formula for the wedge angle α. The cylindrical element can rotate 360° in both the axial and circumferential directions.

[0063] Example 1

[0064] like Figure 1 As shown in the figure, the major axis a of the real ellipse can be expressed by measuring the basic parameters a' and φ of the projected ellipse using mathematical functions; Figure 8 As shown, the oblique cross section of the cylindrical element is projected by the projection module (CCD camera); and the projection contour of the oblique cross section of the cylindrical element is received and displayed by the receiving module. Figure 4 As shown, the wedge angle plane is in the shape of an ellipse, and the short axis of the ellipse is marked as a and the long axis is marked as b through the short axis marking module and the long axis marking module. The component to be tested is placed horizontally along the axis, and the projection module (CCD camera) is placed perpendicular to the axis of the ellipse to collect the projection image of the ellipse outline. Figure 5 As shown. We observe that the minor axis of the ellipse is a, and the major axis b is projected on the cross-section surface (projection surface) of the cylinder as a' and b' respectively. Figure 4 When the major axis b of the ellipse rotates along the central axis, the curved surface swept is the one with the cylinder diameter φ as the base circle diameter.

[0065] Two opposite conical surfaces, and the minor axis a forms a circle with the cone vertex as the center and the cylinder diameter φ as the diameter.

[0066] We assume that the axis of the cylindrical part to be measured is placed horizontally, and the long end of the part is at the lowest position as the standard position, at which time the minor axis a is parallel to the horizontal plane. When the measured part rotates by an angle β around the axis, the minor axis and major axis of the ellipse also rotate by an angle β relative to the original mid-section (projection plane). At this time, the projection lengths of the major axis and minor axis are respectively:

[0067] b'=φcosβ,(a') 2 =(acosα) 2 +(asinα·sinβ) 2 ;

[0068] ( a ') 2 =( ac osα) 2 +( as inα·sinβ) 2

[0069] ( a ') 2 =a 2 (s in 2 αsin 2 β+cos 2 α)

[0070] according to

[0071] have to:

[0072] Depend on: have to:

[0073]

[0074] And because: so: like Figure 7 As shown, finally, the parameter data values ​​are collected to the calculation processing module through the data collection module, and the calculation processing module substitutes them into the above formula to calculate the bevel angle of the cylindrical part.

[0075] The existing C-Lens wedge angle detection process needs to be completed manually. After the C-Lens is cleaned, it needs to be clamped and placed once. For optical detection, it needs to be clamped and placed once, and after the detection is completed, it needs to be clamped and placed back again. Through the new detection method, direct detection can be achieved after cleaning, without multiple clamping and placement, the process of wedge angle detection can be completed, and at least 20 C-Lens can be detected at a time. Detecting 1 C-Lens reduces 2 clamping and placement work. The clamping and placement time required for a single C-Lens is calculated as 1 second (the placement of the detection link only takes 3 seconds to complete), and the wedge angle detection time of each C-Lens will be shortened by 2 seconds. If 20 C-Lens are detected at the same time, the original detection method takes 60 seconds. Using the new wedge angle algorithm, it is estimated that it takes about 5 seconds to take 20 components and complete the detection at the same time (a special stage can be designed to quickly place C-Lens, and the computer detection speed is high). Calculated based on a medium-sized factory that produces 1 million pieces per month and 10 million pieces per year, the traditional testing method requires 3×10 million / 3600=8333 hours, and 1042 working days based on 8 working hours per day. Calculated based on 251 working days per year, 4.2 employees are required to do testing for one year. Using the new testing method: the enterprise needs 10 million / (20×3600)=139 hours, which will reduce 8194 hours for the enterprise. Calculated based on 8 working hours per day, it only takes 17 working days to complete the testing. Calculated at 20 yuan / hour for each testing employee, the enterprise can save 8194×20=163,800 yuan. There are many C-Lens processing enterprises in the province, and the cost savings of large C-Lens processing enterprises can be deduced by analogy. The economic benefits brought are considerable. Calculated based on an annual total output of 1 billion pieces, it will save domestic C-Lens enterprises about 16.38 million yuan / year. And it provides effective guarantee for enterprises to increase their production scale. If other parameter tests of C-Lens are added in the future, it is possible to further double the production efficiency, which can save more costs for the enterprise.

[0076] In summary, through the algorithm and measurement device of the bevel angle of a cylindrical component, when the cylindrical component is placed horizontally along the axis, full-posture online wedge angle calculation can be achieved under the conditions of axial 360° rotation and circumferential 360° rotation; the design and application of the detection system based on the algorithm can quickly and simultaneously detect multiple components, simplify the detection steps, realize detection automation, and improve detection efficiency; the application of the measuring device does not require a special fixture to place the component for detection, reducing errors caused by eccentric component clamping, and coaxiality between the light source and the component; the invention provides an algorithm for detecting the bevel angle of a cylindrical component, and also provides a design of a detection system based on this algorithm.

[0077] The above-mentioned are only preferred embodiments of the present invention and cannot limit the scope of the present invention. All equivalent changes and decorations made according to the scope of the patent application of the present invention should still fall within the scope of the present invention.

Claims

1. A method for measuring the angle of a cylindrical part, characterized in that: The measurement method includes: Contour map collection step: collect the oblique cross-section projection contour map of the cylindrical component; Parameter marking step: marking the parameters of the drawn projection contour map; Angle calculation steps: By formula: Calculate the bevel angle of cylindrical parts; Where a' is the projection length of the minor axis of the wedge angle ellipse profile on the projection surface when the collection device collects the wedge angle ellipse profile in the direction perpendicular to the axis of the cylindrical element; Wherein b' is the projection length of the major axis of the wedge angle ellipse profile on the projection surface when the collection device collects the wedge angle ellipse profile in the direction perpendicular to the axis of the cylindrical element; Where φ is the diameter of the circular cross section of the cylinder perpendicular to the axis.

2. A method for measuring the angle of a cylindrical part according to claim 1, characterized in that: The acquisition device in the contour map acquisition step is a CCD camera.

3. A method for measuring the angle of a cylindrical part according to claim 1, characterized in that: The parameter marking step comprises: a, mark the minor axis of the ellipse outline as a; b, mark the major axis of the ellipse outline as b; c. Mark the diameter of the cylinder's vertical axis section circle as φ.

4. An angle measuring device for use in a method for measuring the angle of a cylindrical part bevel according to any one of claims 1 to 3, the angle measuring device comprising: Contour map acquisition module: collects the oblique cross-section projection contour map of cylindrical components; Parameter marking module: mark the parameters of the drawn projection contour map; Angle calculation module: calculate the angle of the inclined surface of cylindrical parts; The parameter marking module is connected to the angle calculation module.

5. An angle measuring device according to claim 4, characterized in that: The profile map acquisition module comprises: Projection module: Project the oblique section of cylindrical components; Receiving module: Receive and display the oblique cross-section projection contour of the cylindrical component.

6. An angle measuring device according to claim 4, characterized in that: The parameter marking module includes: Minor axis marking module: marks the minor axis of the ellipse contour; Long axis marking module: mark the long axis of the ellipse contour; The short axis marking module is connected to the long axis marking module.

7. An angle measuring device according to claim 4, characterized in that: The angle calculation module comprises: Data collection module: collects data required for angle calculation; Calculation processing module: Substitute the collected data into the angle calculation formula for calculation; The data collection module is connected to the calculation processing module.

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