Liner coating defect detection method, device and equipment and storage medium

Abstract

The invention discloses an inner container coating defect detection method, device and equipment and a storage medium. The inner container coating defect detection method comprises the steps that an oil film layer is formed on the surface of a coating of a kitchen ware inner container; the kitchen ware is controlled to be heated to a first preset temperature, so that the oil film layer serves as a developing medium, and carbonized black spots are formed at the defect position of the coating; and determining a defect area and a defect type of the coating based on analysis of the carbonized black spots. According to the inner container coating defect detection method, device and equipment and the storage medium disclosed by the invention, the problems that a detection mode is low in intelligent degree and needs to consume more manpower and material resources are solved, oil serves as a dielectric layer, and an oil product at the defect position is actively induced to be carbonized by utilizing power-on self-heating so as to form carbonized black spots; invisible defects on the surface of the coating are converted into visible mark signals, optical / infrared equipment and manual detection are not needed, passive detection is changed into active development, defect development detection can be achieved through a heating element of a product, and the detection quality of the coating is ensured.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the field of household appliance self-detection, and in particular to a liner coating defect detection method, device, equipment and storage medium. BACKGROUND

[0002] In the field of household appliances, the inner liner of kitchenware (such as electric chafing dish) is often provided with a coating. The inner liner coating is extremely important for kitchenware, and the quality of the inner liner coating is directly related to the use experience, cooking effect and durability of the kitchenware, as well as the cleaning convenience and food safety of the user.

[0003] In some technologies, for coating inspection, the appearance is currently judged by manual operation whether it is pitted, concave, loss of luster, fading, cracking, exposed bottom, scratch and the like. However, the detection quality of the coating is not uniform for long-time manual operation, which leads to a large fluctuation in the quality of the product. Moreover, the above detection method has low intelligence degree and needs to consume more manpower and resources. SUMMARY

[0004] The purpose of the present application is to at least provide a liner coating defect detection method, device, equipment and storage medium, which can at least solve the technical problems that the detection quality of the coating is not uniform for long-time manual operation, which leads to a large fluctuation in the quality of the product; and the above detection method has low intelligence degree and needs to consume more manpower and resources, and at least achieve the technical effects that oil is used as a medium layer, the oil product at the defect is carbonized to form carbonized black spots by using active induction, the invisible defects on the coating surface are converted into visible mark signals, the detection does not need optical / infrared equipment and manual detection, the "passive detection" is changed into "active development", the defect development detection can be realized by using the heating element of the product itself, and the detection quality of the coating is ensured.

[0005] To solve the above technical problems, at least one embodiment of the present application provides a liner coating defect detection method, comprising: forming an oil film layer on the coating surface of the inner liner of the kitchenware; controlling the kitchenware to heat to a first preset temperature, so that the oil film layer serves as a development medium and forms carbonized black spots at the defects of the coating; based on analyzing the carbonized black spots, determining the defect area and defect type of the coating.

[0006] At least one embodiment of the present application also provides a liner coating defect detection device, comprising a temperature sensor, a PID controller and a control unit. The control unit is used to form an oil film layer on the coating surface of the inner liner of the cookware; control the cookware to heat to a first preset temperature, acquire temperature change information through the temperature sensor during the heating process of the cookware, and control the PID controller to adjust the heating power of the cookware; so that the oil film layer acts as a developing medium to form carbonized black spots at the defects of the coating; and determine the defect area and defect type of the coating based on the analysis of the carbonized black spots.

[0007] At least one embodiment of this application also provides a device for detecting defects in the inner liner coating, comprising: The first control module is used to form an oil film layer on the coating surface of the inner liner of the kitchen utensil; The second control module is used to control the kitchenware to heat up to a first preset temperature so that the oil film layer acts as a developing medium to form carbonized black spots at the defects of the coating. The analysis module is used to determine the defect area and defect type of the coating based on the analysis of the carbonized black spots.

[0008] At least one embodiment of this application also provides an electronic device, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the above-described method for detecting defects in the inner liner coating.

[0009] At least one embodiment of this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for detecting defects in the inner liner coating.

[0010] The embodiments of this application provide a method, apparatus, device, and storage medium for detecting defects in the inner liner coating of a kitchen utensil. An oil film layer is formed on the coating surface of the utensil's inner liner. The utensil is heated to a first preset temperature, causing the oil film layer to act as a developing medium, forming carbonized black spots at the defects in the coating. Then, based on the analysis of the carbonized black spots, the defect area and defect type at the coating defect are determined. Thus, by using oil as a medium layer and actively inducing carbonization of the oil at the defect location through self-heating via electricity, carbonized black spots are formed, converting invisible defects on the coating surface into visible marker signals. This eliminates the need for optical / infrared equipment and manual inspection, transforming "passive detection" into "active development." Defect development and detection can be achieved using the product's own heating element, ensuring the quality of coating detection.

[0011] In some optional embodiments, the oil film layer is formed by pouring edible oil onto the coating surface of the inner liner; wherein the first preset temperature is the oil decomposition temperature of the edible oil, the edible oil is a vegetable oil with a smoke point lower than a second preset temperature, and the second preset temperature is lower than the oil decomposition temperature.

[0012] In this way, edible oils are more readily available and less expensive, reducing the manpower and material costs required for coating testing. By selecting edible oils with low smoke points, a buffer period is provided for testing personnel between the appearance of smoke and the formation of carbonization. When smoke appears, the focus can be placed on the formation of carbonized black spots on the coating surface, preventing the oil temperature from rising too quickly to the oil's decomposition temperature and causing carbonized black spots to form on the coating surface.

[0013] In some optional embodiments, after controlling the cookware to heat to a first preset temperature so that the oil film layer acts as a developing medium to form carbonized black spots at defects in the coating, the method further includes: The temperature of the carbonized black spot and the temperature of the intact area in the coating other than the carbonized black spot are obtained; The edge sharpness of the carbonized black spot is determined based on the temperature of the carbonized black spot, the temperature of the intact area, and the distance between the boundary of the carbonized black spot and the intact area. The step of determining the defect areas of the coating based on the analysis of the carbonized black spots includes: Based on the edge sharpness of the carbonized black spots, the geometric center and defect boundary of the defect area of ​​the coating are determined.

[0014] In this way, the gradient value of the temperature gradient reflects the edge sharpness of the carbonized black spot, so as to better highlight the defect area and accurately lock the geometric center of the defect, effectively avoiding the positioning deviation caused by the spread of the black spot.

[0015] In some optional embodiments, determining the defect type of the coating based on analysis of the carbonized black spots includes: Based on the development characteristics of the carbonized black spots, the defect type of the defect area is determined; the defect type includes microcracks, bubbles, and coating peeling.

[0016] Thus, based on the development characteristics of carbonized black spots, the defect type at the coating defect can be determined, and the defect type can be distinguished in a short time by the development characteristics of carbonized black spots.

[0017] In some optional embodiments, the method further includes: Temperature change information is acquired during the heating process of the kitchen utensils; Based on the temperature change information, the heat capacity of the coating, and the preset heat conduction model, the heat flux density transferred to the substrate of the inner liner is calculated. Based on the comparison between the heat flux density and the preset defect development heat flux density, the PID controller adjusts the heating power of the kitchenware.

[0018] In this way, uneven heating or overheating caused by power supply voltage fluctuations, ambient temperature changes, and differences in pot material can be avoided. This ensures that only the oil temperature at the defective area can exceed the oil decomposition temperature, while the edible oil in the intact area will never carbonize, thus fundamentally eliminating the risk of misjudging defects.

[0019] In some optional embodiments, determining the defect type of the coating based on analysis of the carbonized black spots includes: Determine the distribution characteristics of the heat flux density of the carbonized black spots; The defect type of the coating is determined by judging the development characteristics of the carbonized black spots and the distribution characteristics of the heat flux density of the carbonized black spots.

[0020] Thus, in addition to relying on the image morphology of carbonized black spots (i.e. development features), heat flux density distribution features are also introduced as a key criterion to form a two-factor verification to determine the defect type, which greatly improves the accuracy of coating defect identification. Attached Figure Description

[0021] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, and these illustrative descriptions do not constitute a limitation on the embodiments.

[0022] Figure 1 This is a schematic flowchart of a method for detecting defects in the inner liner coating provided in one embodiment of this application; Figure 2 This is a schematic flowchart of an inner liner coating defect detection device provided in one embodiment of this application; Figure 3 This is a schematic diagram of the structure of an electronic device provided in another embodiment of this application; Figure 4 This is a flowchart illustrating a method for detecting defects in the inner liner coating provided in one embodiment of this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this application to help readers better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments. The division of the various embodiments below is for the convenience of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0024] To facilitate understanding of the embodiments of this application, the relevant content regarding the method for detecting defects in the inner liner coating will be introduced first.

[0025] In the home appliance industry, the inner pot of cookware (such as electric hot pot) is often coated. The inner pot coating is extremely important for cookware, as its quality directly affects the user experience, cooking effect and durability, as well as the user's ease of cleaning and food safety.

[0026] In some technologies, coating inspection currently relies on manual judgment to check for defects such as bumps, dents, loss of gloss, fading, cracking, exposed substrate, and scratches. However, long-term manual operation results in inconsistent coating inspection quality, leading to significant fluctuations in product output quality. Furthermore, the aforementioned inspection methods have low levels of automation and require substantial manpower and resources.

[0027] To address the issues of inconsistent coating quality resulting from prolonged manual operation, which significantly impacts product output quality, and the low level of automation in these methods, requiring substantial manpower and resources, this invention proposes a method for detecting defects in the inner liner coating. The implementation details of this method are described below. These details are provided for ease of understanding and are not essential for implementing this solution.

[0028] Example 1: The defect detection method for the inner liner coating in this embodiment can be applied to electronic devices with communication, computing, and data storage capabilities. The specific process can be as follows: Figure 1 As shown, it includes: Step 101: Form an oil film layer on the coating surface of the inner liner of the kitchen utensil.

[0029] Specifically, the kitchenware is the product to be tested to detect defects on the coating surface of the inner liner. In this embodiment, a pre-placed medium layer is used. Oil is poured onto the coating surface of the cleaned inner liner, allowing the oil to flow naturally and level on the coating surface. The mixture is then left to stand for a period of time (e.g., 1 minute) to allow the oil film to evenly cover the coating surface, forming an oil film layer (i.e., the medium layer). In some examples, the oil film thickness is 0.3 ± 0.05 mm.

[0030] Step 102: Control the kitchenware to heat to a first preset temperature so that the oil film layer acts as a developing medium to form carbonized black spots at the defects of the coating.

[0031] Specifically, the coating is applied to the metal substrate of the cookware's inner liner, forming an oil film on the coating surface. The heating element inside the cookware is then energized and self-heated until it reaches a first preset temperature. At this point, the oil film acts as a developing medium, forming carbonized black spots at defects in the coating. It can be understood that when the coating surface has defects, the coating is damaged at the defects, causing the inner liner to leak out of the metal substrate. The metal directly conducts heat, causing the oil temperature at the defective area to exceed the first preset temperature, leading to oil decomposition and the formation of carbonized black spots at the coating defects. In contrast, in intact areas of the coating surface, the intact coating acts as insulation, resulting in an oil temperature below the first preset temperature, keeping the oil liquid and preventing the formation of carbonized black spots. In some examples, the cookware's heating parameters include power, heating time, and heating voltage. For instance, the power is 2000W (full power), the heating time is 90 seconds (until the oil temperature reaches the first preset temperature), and the heating voltage is 220V (standard AC power).

[0032] Step 103: Based on the analysis of carbonized black spots, determine the defect areas and defect types of the coating.

[0033] Specifically, since the location of carbonized black spots does not necessarily indicate a defect in the coating, it is highly likely that false positive carbonization will occur due to proximity to the first preset temperature. Therefore, in this application, after carbonized black spots are formed on the coating surface, the carbonized black spots are analyzed to determine the defect area of ​​the coating defect based on their location, and the defect type of the coating defect is obtained based on the image morphology of the carbonized black spots.

[0034] In this embodiment, an oil film layer is formed on the coating surface of the inner liner of the kitchen appliance. The kitchen appliance is heated to a first preset temperature, so that the oil film layer acts as a developing medium, forming carbonized black spots at the defects in the coating. Then, based on the analysis of the carbonized black spots, the defect area and defect type at the coating defect are determined. In this way, by using oil as a medium layer, the carbonization of the oil at the defect is actively induced by electric self-heating, thereby forming carbonized black spots. The invisible defects on the coating surface are transformed into visible marking signals. There is no need for optical / infrared equipment for detection, and no need for manual inspection. "Passive detection" is transformed into "active development". Defect development and detection can be achieved using the product's own heating element, and the detection quality of the coating is ensured.

[0035] In some embodiments, the oil film layer is formed by pouring edible oil onto the coating surface of the inner liner; wherein, the first preset temperature is the oil decomposition temperature of the edible oil, the edible oil is a vegetable oil with a smoke point lower than a second preset temperature, and the second preset temperature is lower than the oil decomposition temperature.

[0036] Specifically, since edible oil is more readily available and less expensive, reducing the manpower and resources required for coating inspection, the oil film layer is composed of edible oil, which is formed by pouring edible oil onto the coating surface of the inner liner. When the cookware is heated to a first preset temperature, which is the decomposition temperature of the edible oil, the edible oil carbonizes upon reaching this temperature, resulting in carbonized black spots.

[0037] In this embodiment, the edible oil is a vegetable oil with a low smoke point, such as rapeseed oil or sunflower oil. The smoke point of the edible oil must be lower than a second preset temperature, which is lower than the oil decomposition temperature. The smoke point of edible oil is its smoking temperature. Oil decomposition only occurs when the oil temperature reaches the smoke point and continues to be heated; that is, the smoke point (smoking temperature) is a precursor to oil decomposition. Furthermore, selecting a low smoke point edible oil (such as rapeseed oil with a smoke point of 205°C) allows for staged development: because the metal at the defect directly conducts heat, the oil temperature at the defect is higher. After the oil temperature reaches the smoke point, the edible oil smokes. Until the oil temperature at the defect reaches the oil decomposition temperature, the edible oil carbonizes, thus forming carbonized black spots at the defect. The time between the appearance of smoke and the formation of carbonization provides a buffer period for testing personnel. When smoke appears, they can focus on the formation of carbonized black spots on the coating surface to avoid the oil temperature from rising too quickly to the oil's decomposition temperature, which would cause carbonized black spots to form on the coating surface. At this time, carbonized black spots do not indicate a defect in the coating surface, because when the oil temperature rises to the oil's decomposition temperature, the edible oil will carbonize.

[0038] In this embodiment, the intact areas of the coating surface, excluding the defective areas, have a heat-insulating effect due to the intact coating, resulting in a different oil temperature in the intact areas compared to the defective areas. When the oil reaches its smoke point, the cooking oil smokes, but because the oil temperature in the intact areas is lower than the first preset temperature, the oil remains liquid and does not form carbonized black spots. Therefore, this does not interfere with the determination of coating defects.

[0039] In this embodiment, low smoke point vegetable oils are preferred when selecting edible oils. This is because if high smoke point oils (such as refined peanut oil with a smoke point of 230°C) are used, the intact areas of the coating may approach the oil's decomposition temperature during heating, leading to false positive carbonization. This results in the intact areas of the coating being misjudged as defects during testing. In some examples, rapeseed oil is used as the developing medium. Rapeseed oil has a smoke point of 205°C, a second preset temperature of 230°C, and a decomposition temperature of 280°C. When controlling the heating of the cookware, the heating element uniformly heats the metal substrate. The heat transfer efficiency differs between the intact and defective areas of the coating. Specifically, in the intact area: the coating is heat-insulating (low thermal conductivity), the oil temperature is <280°C (actually measured at approximately 250°C), and the oil only smokes without carbonizing; in the defective area: the metal substrate directly contacts the oil film (fast heat conduction), and the local oil temperature exceeds 300°C, triggering carbonization. When the cookware is powered on and self-heating, the oil temperature at the defective area first reaches 205℃ (smoke point), causing the cooking oil to smoke. The temperature then gradually rises until it reaches 280℃ (oil decomposition temperature), at which point carbonized black spots form. Meanwhile, in the intact area, due to the complete coating, the oil temperature is below 280℃, preventing the formation of carbonized black spots. Furthermore, because the smoke point is less than 230℃, the oil temperature in the intact coating area is below the oil decomposition temperature, thus avoiding misjudgment of defects.

[0040] In some embodiments, after controlling the cookware to heat to a first preset temperature so that the oil film layer acts as a developing medium to form carbonized black spots at defects in the coating, the method further includes: The temperature of the carbonized black spots and the temperature of the intact areas in the coating, excluding the carbonized black spots, were obtained. The edge sharpness of the carbonized black spot is determined based on the temperature of the carbonized black spot, the temperature of the intact area, and the distance between the boundary of the carbonized black spot and the intact area. Based on the analysis of carbonized black spots, the defect areas of the coating were identified, including: Based on the edge sharpness of the carbonized black spots, the geometric center and defect boundary of the defect area of ​​the coating are determined.

[0041] Specifically, because the metal at the coating defects conducts heat directly, the oil temperature at the defects is higher, while the intact areas, due to the intact coating, act as insulation, resulting in a different oil temperature in the intact areas compared to the defects. In this application, a kitchen appliance is powered on and self-heats, using the oil film layer as a developing medium. After carbonized black spots are formed at the coating defects, the oil temperature of the carbonized black spots and the oil temperature of the intact areas of the coating (excluding the carbonized black spots) are obtained. Based on the temperature of the carbonized black spots, the temperature of the intact areas, and the distance between the boundary of the carbonized black spots and the intact areas, a temperature gradient is calculated. The temperature gradient describes the thermal abrupt change at the defect boundary, representing the temperature difference per unit distance, reflecting the edge sharpness of the carbonized black spots. The temperature gradient of the carbonized black spots is calculated using the following formula: ΔT / Δx = (T_defect - T_intact) / d; In the formula, ΔT / Δx is the temperature gradient, which represents the temperature difference per unit distance; T_defect is the oil temperature of the carbonized black spot; T_intact is the oil temperature of the intact area; and d is the distance from the boundary of the carbonized black spot to the intact area.

[0042] In this embodiment, the gradient value of the temperature gradient reflects the edge sharpness of the carbonized black spot, thus better highlighting the defect area. The temperature gradient formula serves as a physical criterion for preventing misjudgment. Its specific function is to accurately locate the geometric center of the defect, effectively avoiding positioning deviations caused by the spread of the black spot. In some cases, when the temperature gradient is high, the boundary of the carbonized black spot is clear (such as a linear crack), allowing for accurate defect location; however, when the temperature gradient is low, the carbonized black spot may spread, increasing the risk of misjudgment. For example, if the oil temperature of the carbonized black spot is 320℃ and the oil temperature of the intact area is 250℃, and the boundary distance between them is d=1mm, then ΔT / Δx=70℃ / mm. This indicates that the carbonized outline of the black spot is sharp and the carbonized boundary is clear, enabling precise location of the geometric center of the defect and effectively avoiding positioning deviations caused by the spread of the black spot.

[0043] In some embodiments, the defect type of the coating is determined based on the analysis of carbonized black spots, including: Based on the development characteristics of carbonized black spots, the defect type of the defect area is determined; the defect types include microcracks, bubbles, and coating peeling.

[0044] Specifically, when the kitchen appliance is powered on and self-heats, carbonized black spots spontaneously form at the defective area within 90 seconds. At the defective area of ​​the coating, the oil temperature is too high, leading to pyrolysis and carbonization, forming carbonized black spots. Based on the development characteristics of these carbonized black spots, the defect type at the coating defective area can be determined. The defect type can be distinguished in a short time by the development characteristics of the carbonized black spots. The specific correspondence between defect type, development characteristics, and development time can be determined using the table below.

[0045] Table 1 Defect Type Correspondence Table

[0046] In some embodiments, the method further includes: Acquire temperature change information during the heating process of kitchen utensils; Based on temperature change information, the heat capacity of the coating, and a preset heat conduction model, the heat flux density transferred to the substrate of the inner liner is calculated. Based on the comparison between the heat flux density and the preset defect development heat flux density, the PID controller adjusts the heating power of the kitchenware.

[0047] Specifically, a temperature sensor can be pre-installed on the outer wall of the inner pot or near the heating element of the cookware. This sensor acquires temperature change information in real-time or periodically during the heating process, allowing for the determination of the temperature rise curve. Then, based on the temperature rise curve, the thermal melting of the coating material, and a pre-defined heat conduction model, the heat flux density transferred to the metal substrate of the inner pot is calculated in real-time. The heat flux density can be calculated using the following formula: q" = k_metal × ΔT / δ; In the formula, q" is the heat flux density; k_metal is the thermal conductivity of the metal substrate; ΔT is the temperature difference between the oil temperature of the carbonized black spot and the oil temperature of the intact area; and δ is the coating thickness.

[0048] In this embodiment, in the intact area, heat flows through the coating (δ thickness, low k_metal value), resulting in a low heat flux density q"_intact in the oil film layer. However, in the defective area, due to the lack of coating (δ≈0), heat is directly transferred from the metal (high k_metal), leading to a high heat flux density q"_defect in the oil film layer, sometimes increasing by more than five times. This dramatic increase in heat flux density at the defective area causes the oil temperature to rapidly exceed the oil's pyrolysis temperature, resulting in a much faster carbonization rate than in the intact area. Therefore, it ensures that only carbonized black spots at the defective area are developed within 90 seconds, supporting a high-efficiency detection rate of 30 pieces / minute.

[0049] In this embodiment, the PID controller is electrically connected to the kitchen appliance. The real-time calculated heat flux density is compared with the defect development heat flux density in a preset defect development heat flux density curve to obtain a comparison result. Based on the comparison result, the PID controller is then used to adjust the heating power of the kitchen appliance, ensuring that the heat flux density of the metal substrate remains within the optimal development window (e.g., 4.5 - 5.5 kW / m²) throughout the entire heating process. 2This method avoids uneven heating or overheating caused by power supply voltage fluctuations, ambient temperature changes, and differences in pot material. It ensures that only the oil temperature at the defective area exceeds the oil's decomposition temperature, while the oil in the intact area will never carbonize, fundamentally eliminating the risk of misjudging defects.

[0050] In some embodiments, the defect type of the coating is determined based on the analysis of carbonized black spots, including: Determine the distribution characteristics of heat flux density in carbonized black spots; The defect type of the coating is determined by judging the development characteristics of carbonized black spots and the distribution characteristics of the heat flux density of carbonized black spots.

[0051] Specifically, the determination of defect type does not rely solely on the image morphology of carbonized black spots (i.e., development characteristics), but also introduces heat flux density distribution characteristics as a key criterion, forming a two-factor verification, which greatly improves the accuracy of coating defect identification. In this embodiment, after determining the heat flux density distribution characteristics of carbonized black spots, the defect type of the coating is determined based on the development characteristics of carbonized black spots and the heat flux density distribution characteristics of carbonized black spots.

[0052] In some cases, the heat flux density distribution is characterized by a high-gradient, highly continuous linear peak band (q>7kW / m) along the crack path. 2 And gradient > 8kW / m 2 When the heat flux density distribution is / mm, if the linear black lines identified at the coating defect do not exhibit the aforementioned heat flux density distribution characteristics, the defect type at the coating defect is determined to be a scratch or impurity. When the heat flux density distribution characteristics are such that the heat flux density at the bubble under the coating exhibits a standard concentric circular decay distribution with the bubble center as the origin (conforming to the 1 / r law), a machine learning algorithm can fit the heat flux density distribution at the defect. If the goodness of fit R... 2 If the value is greater than 0.95, the defect type at the coating defect location is determined to be a bubble defect. When the heat flux density distribution characteristics are such that the heat flux density of a large-area peeling area presents a high q" plateau region with sharp boundaries and uniform internal structure, the standard deviation of the q" value in this region is calculated (e.g., if <0.3kW / m). 2 ) and compare the q" value with the surrounding intact areas with a sudden jump (e.g., difference > 4kW / m). 2 By accurately locating the area of ​​detachment and calculating its area, the defect type at the coating defect can be determined as coating detachment.

[0053] Example 2: The inner liner coating defect detection device in this embodiment includes: a temperature sensor, a PID controller, and a control unit; The control unit is used to form an oil film layer on the coating surface of the inner liner of the cookware; control the cookware to heat to a first preset temperature, acquire temperature change information through a temperature sensor during the heating process of the cookware, and control the PID controller to adjust the heating power of the cookware; so that the oil film layer acts as a developing medium to form carbonized black spots at the defects of the coating; and determine the defect area and defect type of the coating based on the analysis of the carbonized black spots.

[0054] In this embodiment, a coating is applied to the metal substrate of the inner liner of the kitchen appliance, forming an oil film layer on the coating surface. The heating element inside the kitchen appliance is energized and self-heated until it reaches a first preset temperature. At this point, the oil film layer acts as a developing medium, forming carbonized black spots at the defects in the coating. After the carbonized black spots form on the coating surface, they are analyzed. Based on the location of the carbonized black spots, the defect area at the coating defect is determined, and based on the image morphology of the carbonized black spots, the defect type at the coating defect is obtained.

[0055] In this embodiment, the oil film layer is formed by pouring edible oil onto the coating surface of the inner liner. The first preset temperature is the oil decomposition temperature of the edible oil, and the edible oil is a vegetable oil with a smoke point lower than a second preset temperature, which is also lower than the oil decomposition temperature. The intact areas of the coating surface, excluding defects, act as insulation due to the intact coating, resulting in a different oil temperature in the intact areas compared to the defective areas. When the oil reaches its smoke point, it smokes, but because the oil temperature in the intact areas is lower than the first preset temperature, the oil remains liquid and does not form carbonized black spots. Therefore, this does not interfere with the identification of coating defects.

[0056] In this embodiment, the kitchen appliance is powered on and self-heats, so that the oil film layer acts as a developing medium. After carbonized black spots are formed at the defects of the coating, the oil temperature of the carbonized black spots and the oil temperature of the intact area of ​​the coating (excluding the carbonized black spots) are obtained. Based on the temperature of the carbonized black spots, the temperature of the intact area, and the distance between the boundary of the carbonized black spots and the intact area, the temperature gradient is calculated. The temperature gradient is used to describe the thermal abrupt change at the defect boundary. It represents the temperature difference per unit distance to reflect the edge sharpness of the carbonized black spots. This can accurately lock the geometric center of the defect and effectively avoid positioning deviation caused by the spread of black spots.

[0057] In this embodiment, a temperature sensor is used to acquire temperature change information in real time or periodically during the heating process of the cookware, and its temperature rise curve can be determined based on the temperature change information. Then, based on the temperature rise curve, the thermal melting of the coating material, and a preset heat conduction model, the heat flux density transferred to the metal substrate of the inner liner is calculated in real time. A PID controller is electrically connected to the cookware. The real-time calculated heat flux density is compared with the defect development heat flux density in the preset defect development heat flux density curve to obtain the comparison result; then, based on the comparison result, the PID controller is used to adjust the heating power of the cookware so that the heat flux density of the metal substrate is always maintained at the optimal development window throughout the entire heating process of the cookware.

[0058] Furthermore, after determining the distribution characteristics of the heat flux density of the carbonized black spots, the defect type of the coating is determined based on the development characteristics and heat flux density distribution characteristics of the carbonized black spots. Thus, the determination of the defect type does not rely solely on the image morphology of the carbonized black spots (i.e., development characteristics), but also introduces the heat flux density distribution characteristics as a key criterion, forming a two-factor verification, which greatly improves the accuracy of coating defect identification.

[0059] Example 3: like Figure 4 As shown, this embodiment provides exemplary content for Embodiment 1 and Embodiment 2, that is, an exemplary process for a method and device for detecting defects in the inner liner coating, specifically including: 1. Pre-filled medium layer: After cleaning, pour edible vegetable oil (rapeseed oil / soybean oil) into the inner liner. Oil film thickness: 0.3±0.05mm (naturally leveled). Standing time: 1 minute (oil film evenly covered). 2. Power-on self-heating: Connect the electric hot pot to its own heating element. Heating parameters: Power: 2000W (full power), Time: 90 seconds (oil temperature reaches 280-300℃), Voltage: 220V (standard mains power). 3. Defect visualization mechanism: Area A with intact coating --> provides heat insulation; oil temperature <280℃ B-coating defect area --> direct heat conduction by metal, oil temperature > 300℃, oil cracking, carbonization black spots, defect location.

[0060] 4. Judgment criteria:

[0061] The following is the specific implementation method: An edible oil film (0.2-0.5mm thick) is formed on the surface of the inner pot. The electric hot pot's own heating element is used to heat the oil to its decomposition temperature. Defects are determined based on the morphology of the carbonized black spots. The power is 2000W, and the heating time is 80-100 seconds. The oil used is vegetable oil (rapeseed oil / sunflower oil) with a smoke point ≤220℃. Defect quantification: when the length of linear carbonization is >3mm, it is judged as a crack; when the temperature difference between the carbonized area and the non-carbonized area is >15℃, it is judged as peeling.

[0062] It features: a double critical temperature effect: in the intact oil film region, T < smoke point (220℃), the edible oil remains liquid; in the defect region, T > cracking point (280℃), the edible oil carbonizes and develops at the defect location; Temperature gradient formula: ΔT / Δx = (T_defect - T_intact) / d; In the formula, ΔT / Δx is the temperature gradient, which represents the temperature difference per unit distance; T_defect is the oil temperature of the carbonized black spot; T_intact is the oil temperature of the intact area; and d is the distance from the boundary of the carbonized black spot to the intact area.

[0063] Temperature gradients are used to describe thermal abrupt changes at defect boundaries. They represent the temperature difference per unit distance to reflect the edge sharpness of carbonized black spots.

[0064] In this embodiment, the gradient value of the temperature gradient reflects the edge sharpness of the carbonized black spot, thus better highlighting the defect area. The temperature gradient formula serves as a physical criterion for preventing misjudgment. Its specific function is to accurately locate the geometric center of the defect, effectively avoiding positioning deviations caused by the spread of the black spot. In some cases, when the temperature gradient is high, the boundary of the carbonized black spot is clear (such as a linear crack), allowing for accurate defect location; however, when the temperature gradient is low, the carbonized black spot may spread, increasing the risk of misjudgment. For example, if the oil temperature of the carbonized black spot is 320℃ and the oil temperature of the intact area is 250℃, and the boundary distance between them is d=1mm, then ΔT / Δx=70℃ / mm. This indicates that the carbonized outline of the black spot is sharp and the carbonized boundary is clear, enabling precise location of the geometric center of the defect and effectively avoiding positioning deviations caused by the spread of the black spot.

[0065] Heat flux density at defects is amplified: the heat flux density in the area with missing coating is more than 5 times that in the intact area; Heat flux density can be calculated using the following formula: q" = k_metal × ΔT / δ; In the formula, q" is the heat flux density; k_metal is the thermal conductivity of the metal substrate; ΔT is the temperature difference between the oil temperature of the carbonized black spot and the oil temperature of the intact area; and δ is the coating thickness.

[0066] In this embodiment, in the intact area, heat flows through the coating (δ thickness, low k_metal value), resulting in a low heat flux density q"_intact in the oil film layer. However, in the defective area, due to the lack of coating (δ≈0), heat is directly transferred from the metal (high k_metal), leading to a high heat flux density q"_defect in the oil film layer, sometimes increasing by more than five times. This dramatic increase in heat flux density at the defective area causes the oil temperature to rapidly exceed the oil's pyrolysis temperature, resulting in a much faster carbonization rate than in the intact area. Therefore, it ensures that only carbonized black spots at the defective area are developed within 90 seconds, supporting a high-efficiency detection rate of 30 pieces / minute.

[0067] Furthermore, this embodiment utilizes precise control based on real-time inverted heat flux density values ​​to avoid uneven heating or overheating caused by power supply voltage fluctuations, ambient temperature changes, and differences in pot material. This ensures that only defective areas exceed the pyrolysis temperature, while intact areas never carbonize, fundamentally eliminating defect misjudgment. Specifically, temperature sensors pre-placed near the heating element or on the outer wall of the inner liner monitor the temperature rise curve in real time. Based on the heat capacity and heat transfer model of the coating material, the heat flux density q" transferred to the inner liner substrate is calculated in real time. The real-time heat flux density is compared with the preset ideal defect development heat flux density curve, and the heating power is dynamically adjusted by a PID controller to ensure that the heat flux density of the substrate remains within the optimal development window (e.g., 4.5 - 5.5 kW / m²) throughout the entire heating process. 2 )Inside.

[0068] In this embodiment, the determination of defect type does not rely solely on the image morphology of the black spot, but also introduces heat flux density distribution characteristics as a key criterion, forming a two-factor verification, which greatly improves the recognition accuracy. Specifically: 1. Microcrack identification: A true microcrack defect will have a high-gradient, highly continuous linear peak band of heat flux density along the crack path (q>7kW / m). 2 And gradient > 8kW / m 2 / mm). If the linear black lines identified by the image do not have this heat flow characteristic, they are judged as scratches or impurities.

[0069] 2. Bubble Identification: The heat flux density at the bubble location under the coating exhibits a standard concentric circle decay distribution with the bubble center as the origin (following the 1 / r law). Machine learning algorithms will fit the q" distribution in this region; if the goodness of fit R... 2 If the value is greater than 0.95, it is confirmed as a bubble defect.

[0070] 3. Coating Delamination Identification: Large-area delamination will exhibit a high q" plateau region with sharp boundaries and uniform internal structure. This can be identified by calculating the standard deviation of the q" value within this region (if <0.3kW / m²). 2 ) and compare the q" value with the surrounding intact area (difference > 4kW / m)2 This allows for precise location of the detached area and calculation of its area.

[0071] In this embodiment, after the defect is located, the carbonization residue can be 100% removed by the existing cleaning agent on the production line after cooling. It has the following effects: 1. Truly zero new equipment: utilizing only the existing power supply and cleaning stations on the production line; 2. Intrinsically safe: Uses food-grade vegetable oil (compliant with GB 2716-2018) 3. Anti-false judgment design: Automatic oil film thickness homogenization (surface tension control), carbonization pattern corresponds 1:1 with real defects; this solution transforms the electric hot pot from "the object being tested" to "the testing equipment itself", creating a new path for self-diagnosis of home appliances.

[0072] Example 4: Another embodiment of this application relates to a liner coating defect detection device. The implementation details of this embodiment's liner coating defect detection device are described below. The following implementation details are provided for ease of understanding and are not essential for implementing this solution. A schematic diagram of the liner coating defect detection device in this embodiment can be seen as follows: Figure 2 As shown, it includes: The first control module 201 is used to form an oil film layer on the coating surface of the inner liner of the kitchen utensil; The second control module 202 is used to control the kitchenware to heat to a first preset temperature so that the oil film layer acts as a developing medium to form carbonized black spots at the defects of the coating. Analysis module 203 is used to determine the defect area and defect type of the coating based on the analysis of carbonized black spots.

[0073] In some embodiments, the oil film layer is formed by pouring edible oil onto the coating surface of the inner liner; wherein, the first preset temperature is the oil decomposition temperature of the edible oil, the edible oil is a vegetable oil with a smoke point lower than a second preset temperature, and the second preset temperature is lower than the oil decomposition temperature.

[0074] In some embodiments, the inner liner coating defect detection device includes: The first acquisition module is used to acquire the temperature of the carbonized black spots and the temperature of the intact areas in the coating other than the carbonized black spots; The determination module is used to determine the edge sharpness of carbonized black spots based on the temperature of the carbonized black spots, the temperature of the intact area, and the distance between the boundary of the carbonized black spots and the intact area.

[0075] In some embodiments, the analysis module 203 includes: The region determination unit is used to determine the geometric center and defect boundary of the defect region of the coating based on the edge sharpness of the carbonized black spots.

[0076] In some embodiments, the analysis module 203 further includes: The first type determination unit is used to determine the defect type of the defect area based on the development characteristics of carbonized black spots; the defect types include microcracks, bubbles, and coating peeling.

[0077] In some embodiments, the inner liner coating defect detection device includes: The second acquisition module is used to acquire temperature change information during the heating process of kitchen utensils; The calculation module is used to calculate the heat flux density transferred to the substrate of the inner liner based on temperature change information, the heat capacity of the coating and the preset heat conduction model. The control module is used to control the PID controller to adjust the heating power of the kitchenware based on the comparison result between the heat flux density and the preset defect development heat flux density.

[0078] In some embodiments, the analysis module 203 further includes: A defining unit is used to determine the distribution characteristics of the heat flux density of carbonized black spots; The second type determination unit is used to determine the defect type of the coating based on the development characteristics of the carbonized black spots and the distribution characteristics of the heat flux density of the carbonized black spots.

[0079] It is worth mentioning that all modules involved in this embodiment are logical modules. In practical applications, a logical unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. Furthermore, to highlight the innovative aspects of this application, this embodiment does not introduce units that are not closely related to solving the technical problems proposed in this application; however, this does not mean that other units are absent in this embodiment.

[0080] Example 5: Another embodiment of this application relates to an electronic device, such as... Figure 3 As shown, it includes: at least one processor 901; and a memory 902 communicatively connected to the at least one processor 901; wherein the memory 902 stores instructions executable by the at least one processor 901, the instructions being executed by the at least one processor 901 to enable the at least one processor 901 to perform the inner liner coating defect detection method in the above embodiments.

[0081] The memory and processor are connected via a bus, which can include any number of interconnecting buses and bridges, connecting various circuits of one or more processors and memories. The bus can also connect various other circuits, such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and will not be described further herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be a single element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by the processor is transmitted over the wireless medium via an antenna, which further receives data and transmits it to the processor.

[0082] The processor manages the bus and general processing, and also provides various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory is used to store data used by the processor during operation.

[0083] Example 6: Another embodiment of this application relates to a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the method embodiments described above.

[0084] That is, those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0085] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. A method for detecting defects in the inner liner coating, characterized in that, include: An oil film layer is formed on the coating surface of the inner liner of the kitchenware; The kitchen utensils are heated to a first preset temperature so that the oil film layer acts as a developing medium to form carbonized black spots at the defects of the coating. Based on the analysis of the carbonized black spots, the defect areas and defect types of the coating are determined.

2. The method for detecting defects in the inner liner coating according to claim 1, characterized in that, The oil film layer is formed by pouring edible oil onto the coating surface of the inner liner; wherein, the first preset temperature is the oil decomposition temperature of the edible oil, the edible oil is a vegetable oil with a smoke point lower than the second preset temperature, and the second preset temperature is lower than the oil decomposition temperature.

3. The method for detecting defects in the inner liner coating according to claim 1, characterized in that, After controlling the kitchenware to heat to a first preset temperature so that the oil film layer acts as a developing medium to form carbonized black spots at defects in the coating, the method further includes: The temperature of the carbonized black spot and the temperature of the intact area in the coating other than the carbonized black spot are obtained; The edge sharpness of the carbonized black spot is determined based on the temperature of the carbonized black spot, the temperature of the intact area, and the distance between the boundary of the carbonized black spot and the intact area. The step of determining the defect areas of the coating based on the analysis of the carbonized black spots includes: Based on the edge sharpness of the carbonized black spots, the geometric center and defect boundary of the defect area of ​​the coating are determined.

4. The method for detecting defects in the inner liner coating according to any one of claims 1-3, characterized in that, The determination of the defect type of the coating based on the analysis of the carbonized black spots includes: Based on the development characteristics of the carbonized black spots, the defect type of the defect area is determined; the defect type includes microcracks, bubbles, and coating peeling.

5. The method for detecting defects in the inner liner coating according to claim 1, characterized in that, The method further includes: Temperature change information is acquired during the heating process of the kitchen utensils; Based on the temperature change information, the heat capacity of the coating, and the preset heat conduction model, the heat flux density transferred to the substrate of the inner liner is calculated. Based on the comparison between the heat flux density and the preset defect development heat flux density, the PID controller adjusts the heating power of the kitchenware.

6. The method for detecting defects in the inner liner coating according to claim 5, characterized in that, The determination of the defect type of the coating based on the analysis of the carbonized black spots includes: Determine the distribution characteristics of the heat flux density of the carbonized black spots; The defect type of the coating is determined by judging the development characteristics of the carbonized black spots and the distribution characteristics of the heat flux density of the carbonized black spots.

7. A device for detecting defects in the inner liner coating, characterized in that, include: Temperature sensor, PID controller and control unit; The control unit is used to form an oil film layer on the coating surface of the inner liner of the cookware; control the cookware to heat to a first preset temperature; during the heating process of the cookware, acquire temperature change information through the temperature sensor and control the PID controller to adjust the heating power of the cookware; so that the oil film layer acts as a developing medium to form carbonized black spots at the defects of the coating. Based on the analysis of the carbonized black spots, the defect areas and defect types of the coating are determined.

8. A device for detecting defects in the inner liner coating, characterized in that, include: The first control module is used to form an oil film layer on the coating surface of the inner liner of the kitchen utensil; The second control module is used to control the kitchenware to heat up to a first preset temperature so that the oil film layer acts as a developing medium to form carbonized black spots at the defects of the coating. The analysis module is used to determine the defect area and defect type of the coating based on the analysis of the carbonized black spots.

9. An electronic device, characterized in that, include: At least one processor; as well as, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the inner liner coating defect detection method as described in any one of claims 1 to 6.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the method for detecting defects in the inner liner coating as described in any one of claims 1 to 6.

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