A static droplet contact angle measurement method based on morphological characteristics

Abstract

The present invention relates to the field of contact angle measurement technology, and specifically to a static droplet contact angle measurement method based on morphological features, a computer-readable storage medium, and a computer program product. The static droplet contact angle measurement method based on morphological features provided by the present invention includes the following steps: obtaining a side view image of a droplet in contact with a target surface at a collection time node, and extracting the morphological features of the droplet from the side view image; based on the morphological features of the droplet, matching a target curve fitting model from a curve fitting model library, wherein the curve fitting model library stores a number of curve fitting models; using the target curve fitting model, fitting the geometric shape of the droplet, and based on the geometric shape of the droplet, calculating the contact angle between the droplet and the target surface in the side view image. The present invention breaks through the limitations of traditional methods that rely on fixed models to fit the droplet boundary, making the contact angle measurement process more flexible and more in line with the actual droplet morphological features.

Description

Technical Field

[0001] The present invention relates to the technical field of contact angle measurement, and in particular to a static droplet contact angle measurement method based on morphological characteristics, a computer-readable storage medium and a computer program product. Background Art

[0002] The contact angle of a liquid droplet is an important physical quantity that measures the interaction between a liquid and a solid surface. It is widely used in coatings, surface treatment, microfluidic systems, materials science, environmental engineering, and life sciences.

[0003] In practical applications, the morphology of droplets often changes dynamically due to surface characteristics (such as roughness, curvature and chemical properties) and changes in the external environment (such as temperature and humidity). Especially on porous, irregular or high-curvature surfaces, the complexity of droplet morphology is more significant. Existing contact angle measurement methods usually fit the boundary curve of the droplet based on a fixed boundary fitting model (such as a circle or ellipse). The measurement accuracy and applicability are limited in complex or dynamic scenes, and it is difficult to meet the needs of accurate measurement of the contact angle between the droplet and the surface with changing behavior in complex or dynamic scenes. Summary of the invention

[0004] In view of the limitations of the prior art, the present invention proposes a static droplet contact angle measurement method based on morphological features, a computer-readable storage medium and a computer program product, aiming to solve the problem of contact angle measurement between droplets and surfaces in complex or dynamic scenarios.

[0005] In one embodiment provided by the present invention, the static droplet contact angle measurement method based on morphological characteristics comprises the following steps:

[0006] Acquire a side view image of a droplet in contact with a target surface at a collection time node, and extract morphological features of the droplet from the side view image;

[0007] Based on the morphological characteristics of the droplet, matching a target curve fitting model from a curve fitting model library, wherein the curve fitting model library stores a plurality of curve fitting models;

[0008] The target curve fitting model is used to fit the geometric shape of the droplet, and based on the geometric shape of the droplet, the contact angle between the droplet and the target surface in the side view image is calculated.

[0009] In this embodiment or other embodiments, the morphological characteristics of the droplet are characterized by a droplet contour curve.

[0010] In this embodiment or other embodiments, matching a target curve fitting model from a curve fitting model library based on the morphological characteristics of the droplet includes the following steps:

[0011] Based on a curve fitting model, an optimal parameter set for fitting a droplet profile curve is obtained;

[0012] Using the optimal parameter set of the curve fitting model, the minimum error amount of the curve fitting model fitting the droplet profile curve is obtained;

[0013] Based on the comparison between the minimum error amount of the droplet profile curve fitted by the current curve fitting model and the minimum error amount of the droplet profile curve fitted by other curve fitting models, it is determined whether the current curve fitting model is the target curve fitting model.

[0014] In this embodiment or other embodiments, the optimal parameter set of any curve fitting model is solved by the objective function: ;

[0015] Among them, i, j, and k are serial numbers, n is the number of sample points representing the droplet profile curve, and m represents the curve fitting model. The number of parameters in is the i-th sample point representing the droplet profile curve, Represents a parameter set based Curve fitting model , using the horizontal coordinate of the i-th sample point of the droplet profile curve The ordinate of the i-th sample point of the fitting, is the regularization coefficient, Represents a parameter set based Curve fitting model For parameter sets The kth parameter in The partial derivative of .

[0016] In this embodiment or other embodiments, the minimum error amount of any curve fitting model for fitting the droplet profile curve is calculated by the following model: ;

[0017] Among them, i, j, and k are serial numbers, n is the number of sample points representing the droplet profile curve, and m represents the curve fitting model. The number of parameters in is the i-th sample point representing the droplet profile curve, Represents the optimal parameter set Curve fitting model , using the horizontal coordinate of the i-th sample point of the droplet profile curve The ordinate of the i-th sample point of the fitting, is the regularization coefficient, Represents the optimal parameter set Curve fitting model For the optimal parameter set The kth parameter in The partial derivative of .

[0018] In this embodiment or other embodiments, whether any curve fitting model is a target curve fitting model is determined by the following model: ;

[0019] in, Represents a curve fitting model is the target curve fitting model, Represents a curve fitting model Non-targeted curve fitting models, is the serial number, , Indicates that there is a curve fitting model , the minimum error of the fitting droplet profile curve Less than the curve fitting model Minimum error of fitting droplet profile curve .

[0020] In this embodiment or other embodiments, the contact angle at any contact point between the fitted geometric shape and the target surface satisfies the following calculation model: ;

[0021] in, represents the contact angle, The geometric shape F The horizontal coordinate of the contact point with the target surface, Represents the geometric shape F The partial derivative at the contact point.

[0022] In this embodiment or other embodiments, based on the above-mentioned static droplet contact angle measurement method based on morphological features, a computer-readable storage medium is also provided, and the computer-readable storage medium includes a stored program, wherein when the program is running, the device where the computer-readable storage medium is located is controlled to execute the static droplet contact angle measurement method based on morphological features.

[0023] In this embodiment or other embodiments, based on the above-mentioned static droplet contact angle measurement method based on morphological features, a computer program product is also provided, including a computer program, which implements the steps of the static droplet contact angle measurement method based on morphological features when executed by a processor.

[0024] The static droplet contact angle measurement method based on morphological features, computer-readable storage medium and computer program product provided by the present invention have the following benefits:

[0025] The present invention significantly improves the accuracy and applicability of contact angle measurement by extracting morphological features from the side view image of the droplet and dynamically matching the curve fitting model, breaking through the limitation of the traditional method of relying on a fixed model to fit the droplet boundary, making the measurement process more flexible and more in line with the actual droplet morphological features;

[0026] Furthermore, the present invention constructs a structured curve fitting model library that can meet the needs of fitting various droplet morphological characteristics, and can ensure that the measurement results have high accuracy and reliability under complex surface conditions by dynamically matching the optimal model and combining the principle of minimizing fitting errors;

[0027] Furthermore, the static droplet contact angle measurement method based on morphological characteristics of the present invention also realizes the automation and systematization of the measurement method by designing corresponding computer-readable storage media and computer program products, so that the measurement method of the present invention can be efficiently operated in a variety of devices or measurement systems, meeting the multi-scenario application requirements of industry and scientific research, and significantly reducing deployment costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A flow chart of a method for measuring static droplet contact angle based on morphological features provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0029] In the following description, for the purpose of explanation rather than limitation, specific details such as specific system structures and technologies are provided to facilitate a thorough understanding of the embodiments of the present application.

[0030] However, it should be clear to those skilled in the art that the present application can be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obstructing the description of the present application with unnecessary details.

[0031] In the contact angle measurement process, the boundary curve of the droplet is usually fitted and the contact angle is calculated based on a fixed boundary fitting model, which limits the measurement accuracy and applicability in complex or dynamic scenarios (where the state of the droplet changes over time).

[0032] In one embodiment provided by the present invention, for the measurement of the contact angle between the droplet and the target surface at any acquisition time node, the following is provided: Figure 1 The static droplet contact angle measurement method based on morphological characteristics shown in the figure specifically comprises the following steps:

[0033] S01. Acquire a side view image of a liquid droplet in contact with a target surface at a collection time node, and extract morphological features of the liquid droplet from the side view image.

[0034] It can be understood that at any acquisition time node, the contact angle between the droplet and the target surface is static and unchanged; further, the present invention can be implemented in a dynamic scene, that is, the dynamic scene is divided into continuous static scenes, and in each static scene, the static droplet contact angle measurement method based on morphological features provided in this embodiment is used to calculate the contact angle between the droplet and the target surface.

[0035] Furthermore, the side view image of the droplet in contact with the target surface at any acquisition time point can be obtained by shooting with a high-resolution camera or optical equipment from a perspective parallel to the target surface.

[0036] Furthermore, the morphological features of the droplet in any side view image are characterized by a contour curve of the droplet cross section; specifically, the contour curve of the droplet in any side view image can be extracted by existing image technology, such as the Canny algorithm to extract the droplet edge points to connect them into an edge contour curve.

[0037] S02. Based on the morphological characteristics of the droplet, a target curve fitting model is matched from a curve fitting model library, wherein the curve fitting model library stores a plurality of curve fitting models.

[0038] Furthermore, the curve fitting model library proposed in the present invention is a structured data repository, which stores a number of curve fitting models, such as a circular curve fitting model, an elliptical curve fitting model, a polynomial fitting model, a Bézier curve fitting model, a spline function fitting model, etc.

[0039] Furthermore, the matching of any curve fitting model with the droplet profile curve is achieved through the following steps and calculation models:

[0040] S021. Based on a curve fitting model, obtain an optimal parameter set for fitting the droplet profile curve.

[0041] In this embodiment, the optimal parameter set of any curve fitting model can be obtained by using optimization methods such as gradient descent, least squares method, genetic algorithm, etc. to obtain the optimal solution of the following objective function:

[0042] , where i, j, and K are serial numbers, n is the number of sample points representing the droplet profile curve, and m represents the curve fitting model The number of parameters in is the i-th sample point representing the droplet profile curve, Represents a parameter set based Curve fitting model , using the horizontal coordinate of the i-th sample point of the droplet profile curve The ordinate of the i-th sample point of the fitting, is the regularization coefficient, which usually ranges from to , Represents a parameter set based Curve fitting model For parameter sets The kth parameter in The partial derivative of .

[0043] S022. Using the optimal parameter set of the curve fitting model, obtain the minimum error amount of the curve fitting model in fitting the droplet profile curve.

[0044] In this embodiment, the minimum error amount of any curve fitting model for fitting the droplet profile curve is calculated by the following model:

[0045] ,in, Represents the optimal parameter set Curve fitting model , using the horizontal coordinate of the i-th sample point of the droplet profile curve The ordinate of the i-th sample point of the fitting, Represents the optimal parameter set Curve fitting model For the optimal parameter set The kth parameter in The partial derivative of .

[0046] S023. Determine whether the current curve fitting model is the target curve fitting model based on a comparison of the minimum error of the current curve fitting model in fitting the droplet profile curve with the minimum error of the other curve fitting models in fitting the droplet profile curve.

[0047] In this embodiment, whether any curve fitting model is a target curve fitting model is determined by the following model:

[0048] ,in, Represents a curve fitting model is the target curve fitting model, Represents a curve fitting model Non-targeted curve fitting models, is the serial number, , Indicates that there is a curve fitting model , the minimum error of the fitting droplet profile curve Less than the curve fitting model Minimum error of fitting droplet profile curve .

[0049] S03. Fitting the geometric shape of the liquid droplet using the target curve fitting model, and calculating the contact angle between the liquid droplet and the target surface in the side view image based on the geometric shape of the liquid droplet.

[0050] Furthermore, based on the target curve fitting model F matched in step S02, the geometric shape of the droplet fitted can be expressed as F .

[0051] Furthermore, based on the droplet geometry F , any contact point between it and the target surface , F The contact angle , satisfying the following calculation model:

[0052] ,in, The geometric shape F The horizontal coordinate of the contact point with the target surface, Represents the geometric shape F The partial derivative at the contact point.

[0053] In this embodiment and other embodiments, in relation to the static droplet contact angle measurement method based on morphological features provided in the above-mentioned embodiments, a computer-readable storage medium is also provided, which includes a stored program; when the program is running, the device where the computer-readable storage medium is located controls some or all of the steps in the above-mentioned static droplet contact angle measurement method based on morphological features.

[0054] In this embodiment and other embodiments, a computer program product is also provided for the static droplet contact angle measurement method based on morphological features provided in the above embodiments, which includes a computer program; when the computer program is executed by a processor, it implements some or all of the steps in the above-mentioned static droplet contact angle measurement method based on morphological features.

[0055] Finally, it should be noted that the aforementioned embodiments are only used to illustrate the technical solution of the present invention rather than to limit it, and the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, please refer to the relevant description of other embodiments. Although the aforementioned embodiments have described the present invention in detail, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents.

Claims

1. A static droplet contact angle measurement method based on morphological characteristics, characterized in that: The steps include: Divide the dynamic scene into continuous static scenes, obtain a side view image of the droplet contacting the target surface at a collection time node corresponding to each static scene, and extract a droplet profile curve of the droplet from the side view image; Based on a curve fitting model, an optimal parameter set for fitting a droplet profile curve is obtained, and the minimum error of the curve fitting model for fitting the droplet profile curve is obtained by using the optimal parameter set of the curve fitting model. The optimal parameter set is solved by the following objective function: , minimum error , where i, j, and k are serial numbers, n is the number of sample points representing the droplet profile curve, and m represents the curve fitting model The number of parameters in is the i-th sample point representing the droplet profile curve, Represents a parameter set based Curve fitting model , using the horizontal coordinate of the i-th sample point of the droplet profile curve The ordinate of the i-th sample point of the fitting, is the regularization coefficient, Represents a parameter set based Curve fitting model For parameter sets The kth parameter in The partial derivative of Based on the comparison of the minimum error of the droplet contour curve fitted by the current curve fitting model and the minimum error of the droplet contour curve fitted by other curve fitting models, it is determined whether the current curve fitting model is the target curve fitting model; the geometric shape of the droplet is fitted using the target curve fitting model, and based on the geometric shape of the droplet, the contact angle between the droplet and the target surface in the side view image is calculated.

2. The static droplet contact angle measurement method based on morphological characteristics according to claim 1 is characterized in that: Whether any curve fitting model is the target curve fitting model is determined by the following model: ;in, Represents a curve fitting model is the target curve fitting model, Represents a curve fitting model is a non-target curve fitting model, is the serial number, , Indicates that there is a curve fitting model , the minimum error of the fitting droplet profile curve Less than the curve fitting model Minimum error of fitting droplet profile curve .

3. The static droplet contact angle measurement method based on morphological characteristics according to claim 1 is characterized in that: The contact angle at any contact point between the fitted geometric shape and the target surface satisfies the following calculation model: ;in, represents the contact angle, The geometric shape F The horizontal coordinate of the contact point with the target surface, Represents the geometric shape F The partial derivative at the contact point.

4. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute the static droplet contact angle measurement method based on morphological features according to any one of claims 1 to 3.

5. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the static droplet contact angle measurement method based on morphological features according to any one of claims 1 to 3 is implemented.

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