Method, device, and system for testing static contact angle of reagent asphalt

Patent metadata

Field	Value
Publication number	US-12181397-B2
Application number	US-202217862902-A
Country	US
Kind code	B2
Filing date	Jul 12, 2022
Priority date	Sep 30, 2020
Publication date	Dec 31, 2024
Grant date	Dec 31, 2024

Abstract

Disclosed is a method, device, and system for testing the static contact angle of reagent asphalt, the method includes the following steps: acquiring a side image of a stable droplet formed by a test reagent on asphalt surface, and determining the position of a baseline in the side image; cropping the side image to obtain a droplet image, and extracting droplet contour points in the droplet image; screening out effective contour points corresponding to contours of the two sides of the droplet from the droplet contour points; performing cubic polynomial fitting on the effective contour points to obtain curve function of contour curves on both sides; calculating contact angle value from the curve function and the position of the baseline. The beneficial effects of this disclosure are: this disclosure reduces the difficulty of fitting of the droplet contour and thus improves the calculation precision of the contact angle.

First claim

What is claimed is:

1. A method for testing static contact angle of reagent asphalt, comprising the following steps:
acquiring a side image of a stable droplet formed by a test reagent on asphalt surface, and determining a position of a baseline in the side image, wherein a height direction of the droplet is defined as a y axis coordinate direction, and a vertical direction of the droplet is defined as an x axis coordinate direction, the baseline represents a contact surface between the reagent droplet and the asphalt, a y-coordinate value of the baseline is defined as J;
cropping the side image to obtain a droplet image, and extracting droplet contour points in the droplet image, wherein the extracted contour points comprise a complete droplet contour, an aperture at a center of the droplet, and noise points, extracting droplet contour points in the droplet image comprising:
extracting horizontal and vertical coordinates of all points with a pixel value of 1 in the droplet image to form a contour image, and
assigning the horizontal and vertical coordinates of the points to variables x and y respectively as x and y coordinate values of the contour points;

screening out effective contour points corresponding to contours of two sides of the droplet from the droplet contour points, comprising:
exchanging x and y coordinate values of the contour image of the contour points by rotating the contour image 90° counterclockwise;
selecting the contour points whose x-coordinate values are less than J;
filtering out the contour points of the aperture and the noise points to maintain the complete droplet contour;

performing cubic polynomial fitting on the effective contour points to obtain curve function of contour curves on both sides;
calculating contact angle value from the curve function and the position of the baseline.

2. The method for testing static contact angle of reagent asphalt according to claim 1 , cropping the side image to obtain a droplet image, specifically including the following steps:
taking the height direction of the droplet as a longitudinal direction, and taking the vertical direction of the height direction of the droplet as a horizontal direction;
setting a ratio of the droplet diameter to a lateral length of the droplet image, and setting a ratio of the droplet height to the vertical height of the droplet image;
cropping the side image according to a set ratio to obtain the droplet image.

3. The method for testing static contact angle of reagent asphalt according to claim 1 , extracting droplet contour points in the droplet image, specifically further including the following steps:
converting the droplet image to a grayscale image, and increasing the pixel values of all pixels in the grayscale image;
performing median filtering on the grayscale image;
using Canny operator to extract all the contour points in the grayscale image;
deleting noise contour points in the contour points according to the size and shape of the droplet to obtain the droplet contour points.

4. The method for testing static contact angle of reagent asphalt according to claim 1 , screening out effective contour points corresponding to contours of the two sides of the droplet from the droplet contour points, specifically:
sorting the droplet contour points according to the y-coordinate values of the droplet contour points, and selecting the droplet contour points whose y-coordinate values are greater than a set threshold to obtain the effective contour points corresponding to the contours on both sides.

5. The method for testing static contact angle of reagent asphalt according to claim 1 , calculating contact angle value from the curve function and the position of the baseline, specifically:
calculating intersection points of the baseline and the contour curves on both sides according to the curve function and the position of the baseline;
drawing a tangent to the corresponding side contour curve through the intersection point; calculating a slope of the tangent;
calculating the contact angle value of the corresponding side contour curve from the slope; and
taking an average value of the contact angle of the contours on both sides as the final contact angle value.

6. The method for testing static contact angle of reagent asphalt according to claim 1 , wherein the method also includes the following step:
selecting a variety of test reagents;
acquiring multiple droplet images for each test reagent;
calculating a contact angle value from each droplet image; and
calculating an average value of the contact angle corresponding to the multiple droplet images of each test reagent to obtain the contact angle value of the corresponding type of test reagent.

7. The method for testing static contact angle of reagent asphalt according to claim 1 , wherein the method also includes the following step:
calculating a surface energy parameter of the asphalt from the contact angle value.

8. A device for testing static contact angle of reagent asphalt, comprising a processor and a memory, the memory stores a computer program, and when the computer program is executed by the processor, the method for testing static contact angle of reagent asphalt according to claim 1 is implemented.

9. A system for testing static contact angle of reagent asphalt, comprising the device for testing static contact angle of reagent asphalt as claimed in claim 8 , the system also comprises an optical contact angle meter;
the optical contact angle meter is used for titration of the test reagent and photographing of the side image, and the side image is sent to the device for testing static contact angle of reagent asphalt.

10. A non-transitory computer storage medium, on which a computer program is stored, when the computer program is executed by a processor, the method for testing static contact angle of reagent asphalt as claimed in claim 1 is realized.

11. The method for testing static contact angle of reagent asphalt according to claim 1 , wherein the x-coordinate value of the aperture is between 80 and 160, and the y-coordinate value of the aperture is between 100 and 250.

12. The method for testing static contact angle of reagent asphalt according to claim 4 , further comprising:
arranging the contour points in ascending order of y-coordinate values; and
taking part of the contour points on both sides of the droplet contour that account for ¼ of the total contour as the effective contour points.

Assignees

• Univ Wuhan Tech

Inventors

• Luo Rong
• Niu Longchang
• Luo Jing
• Tu Chongzhi
• Huang Tingting
• Wang Xiang
• Miao Qiang

Classifications

• G01N2013/0208

  by measuring contact angle · CPC title

• G01N13/02 Primary

  Investigating surface tension of liquids · CPC title

• G01N13/00 Primary

  Investigating surface or boundary effects, e.g. wetting power; Investigating diffusion effects; Analysing materials by determining surface, boundary, or diffusion effects (scanning-probe techniques or apparatus G01Q) · CPC title