Method and device for accurately controlling temperature of hair straightener based on power regulation

Abstract

The invention discloses a hair straightener temperature accurate control method and device based on power regulation, and relates to the technical field of temperature control. After the heating plate detects the switch instruction, the heating plate is heated to the preset working temperature at the preset working power; working residual temperature of the heating plate in the service cycle is obtained, a temperature decline curve is obtained according to fitting of the preset working temperature and the working residual temperature, and the curve slope of the temperature decline curve is determined; determining the hair quality of the user according to the curve slope after the first period, and adjusting the working power of the hair straightener according to the hair quality of the user; the temperature is automatically adjusted according to the hair quality of the user, and the problem that the user experience is reduced due to manual adjustment is solved. By intelligently detecting the working residual temperature of the heating plate and fitting the temperature drop curve, the hair quality of the user is automatically judged, and then the working power of the hair straightener is adaptively adjusted, so that the personalized and intelligent heating experience is realized, and the use convenience and satisfaction of the user are greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of temperature control, and in particular relates to a method and device for accurately controlling the temperature of a hair straightener based on power regulation. Background Art

[0002] As a modern personal hairdressing tool, hair straighteners have evolved from professional hair salons to the home market, demonstrating technological innovation and design diversity. Modern hair straighteners not only pursue efficient and convenient hair straightening effects, but also incorporate hair care technology to reduce heat damage and meet the needs of different consumers. With technological advances, hair straighteners will continue to develop in the direction of intelligence and personalization.

[0003] The working principle of a hair straightener is based on heat conduction and shaping technology. It quickly heats up to the set working temperature through a built-in heating module, usually using high-efficiency heating elements such as ceramics, PTC or MCH. The user places the hair between the heating plates, and the heat quickly penetrates the surface of the hair, softening the keratin structure in the hair, making it soft and easy to shape; some high-end hair straighteners also use negative ion technology to release negative ions to neutralize the positive charge on the surface of the hair, reduce static electricity, protect the hair from heat damage, and add gloss and smoothness during the straightening process. Users can adjust the temperature according to their personal needs and achieve the ideal hairstyle effect through simple hand operations such as straightening and curling. The working principle of a hair straightener combines efficient heating technology with hair care technology to bring users a convenient and efficient hairdressing experience.

[0004] Although the above-mentioned hair straightener solves the problem of personalized adjustment of the temperature of the hair straightener, there are still some problems. For example, the hair straightener cannot adaptively adjust the temperature of the hair straightener according to the hair quality of the user, and manual operation is required, which reduces the user experience. Summary of the invention

[0005] The purpose of the present invention is to solve the problem that the hair straightener cannot adaptively adjust the temperature of the hair straightener according to the hair quality of the user, and to propose a method and device for accurately controlling the temperature of the hair straightener based on power regulation.

[0006] In a first aspect of the present invention, a method for accurately controlling the temperature of a hair straightener based on power regulation is first proposed, the method comprising: After the heating plate detects the switch command, the heating plate is heated to a preset working temperature with a preset working power; Obtaining the working residual temperature of the heating plate during the use cycle, fitting a temperature drop curve according to the preset working temperature and the working residual temperature, and determining the slope of the temperature drop curve; the temperature corresponding to each moment in the use cycle is the working residual temperature; After the first cycle, the hair quality of the user is determined according to the slope of the curve, and the working power of the hair straightener is adjusted according to the hair quality of the user.

[0007] Optionally, determining the slope of the temperature drop curve includes: Real-time sampling is performed on the heating plate during its use period to obtain a key point set, and the key points in the key point set are arranged in time series and fitted to obtain a temperature drop curve; The temperature drop curve is divided into a curve segment set according to a preset interval, and the absolute mean value of the curve slope is calculated according to the curve segment set to obtain the curve slope.

[0008] Optionally, calculating the absolute mean value of the curve slope according to the curve segment set to obtain the curve slope includes: Acquire line segment data in the curve segment set, and calculate the line segment data using a judgment formula to obtain a curve slope;

[0009] Among them, F is the slope of the curve, j is the number of line segment data in the curve segment set, is the slope of the line segment data in the curve segment set.

[0010] Optionally, determining the hair quality of the user according to the slope of the curve includes: judging the user's hair quality according to the slope of the curve; If the slope of the curve is greater than the upper threshold of the judgment interval, the user is judged to have fine and soft hair; If the slope of the curve is within the judgment interval, it is judged that the user has normal hair quality; If the slope of the curve is less than the lower threshold of the judgment interval, it is determined that the user has coarse and hard hair.

[0011] Optionally, adjusting the working power of the hair straightener according to the hair quality of the user includes: If the user has coarse and hard hair, the operating frequency and the operating power of the heating plate are reduced and the working cycle time of the heating plate is increased so that the temperature of the heating plate is maintained at the preset working temperature during the working cycle; If the user has normal hair quality, the operating frequency, operating power and operating cycle time of the heating plate are maintained so that the operating temperature of the heating plate is at the preset operating temperature; If the user has fine and soft hair, the operating frequency and the operating power of the heating plate are increased and the working cycle time of the heating plate is reduced so that the temperature of the heating plate is maintained at the preset working temperature during the working cycle.

[0012] In a second aspect of the present invention, a device for precise temperature control of a hair straightener based on power regulation is provided, comprising: the device comprises: an instruction sending module, a slope calculation module and a temperature control module: The instruction sending module is used to heat the heating plate to a preset working temperature with a preset working power after the heating plate detects a switch instruction; The slope acquisition module is used to acquire the working residual temperature of the heating plate during the use cycle, obtain a temperature drop curve according to the preset working temperature and the working residual temperature, and determine the slope of the temperature drop curve; the temperature corresponding to each moment in the use cycle is the working residual temperature; The temperature control module is used to determine the hair quality of the user according to the slope of the curve after the first cycle, and adjust the working power of the hair straightener according to the hair quality of the user.

[0013] Optionally, the slope acquisition module includes: a curve fitting module and a slope division module: The curve fitting module is used to obtain a key point set by real-time sampling of the heating plate during its use period, arrange the key points in the key point set in a time series and perform fitting to obtain a temperature drop curve; The slope division module is used to divide the temperature drop curve into a set of curve segments according to preset intervals, and calculate the absolute mean value of the curve slope according to the set of curve segments to obtain the curve slope.

[0014] Optionally, the slope division module further includes: a slope calculation module: The slope calculation module is used to obtain line segment data in the curve segment set, and calculate the line segment data through a judgment formula to obtain the curve slope;

[0015] Among them, F is the slope of the temperature drop curve, j is the number of line segment data in the curve segment concentration, is the slope of the line segment data in the curve segment set.

[0016] Optionally, the temperature control module includes: a hair quality determination module, a first hair quality module, a second hair quality module and a third hair quality module: The hair quality judgment module is used to judge the hair quality of the user according to the slope of the curve; The first hair quality module is used to determine that the user has fine and soft hair if the slope of the curve is greater than an upper threshold of the judgment interval; The second hair quality module is used to determine that the user has normal hair quality if the slope of the curve is within the judgment interval; The third hair quality module is used to determine that the user has coarse and hard hair if the slope of the curve is less than a lower threshold of the judgment interval.

[0017] Optionally, the temperature control module further includes: a first control module, a second control module and a third control module: The first control module is used for reducing the working frequency and working power of the heating plate and increasing the working cycle time of the heating plate if the user has coarse and hard hair, so that the temperature of the heating plate is maintained at the preset working temperature during the working cycle; The second control module is used for maintaining the working frequency, working power and working cycle time of the heating plate if the user has normal hair quality, so that the working temperature of the heating plate is at the preset working temperature; The third control module is used to increase the working frequency and working power of the heating plate and reduce the working cycle time of the heating plate if the user has fine and soft hair, so that the temperature of the heating plate is maintained at the preset working temperature during the working cycle.

[0018] Beneficial effects of the present invention: The present invention proposes a precise temperature control method for a hair straightener based on power regulation, wherein after the heating plate detects a switch command, the heating plate heats to a preset working temperature with a preset working power; the working residual temperature of the heating plate in the first cycle is obtained, and a temperature drop curve is obtained by fitting the preset working temperature and the working residual temperature, and the slope of the temperature drop curve is determined; after the first cycle, the hair quality of the user is determined according to the slope of the curve, and the working power of the hair straightener is adjusted according to the hair quality of the user; the temperature is automatically adjusted according to the hair quality of the user, thereby reducing the problem of reducing the user experience due to manual adjustment. By intelligently detecting the working residual temperature of the heating plate and fitting the temperature drop curve, the hair quality of the user is automatically determined, and the working power of the hair straightener is adaptively adjusted, a personalized and intelligent heating experience is achieved, and the convenience and satisfaction of the user are greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the accompanying drawings.

[0020] Figure 1 A flow chart of a method for precise temperature control of a hair straightener based on power regulation is provided for an embodiment of the present invention; Figure 2 A schematic structural diagram of a device for precisely controlling the temperature of a hair straightener based on power regulation is provided for an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The term "and / or" herein is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the present invention, the description of "first", "second", etc. is only used for descriptive purposes, and cannot be understood as indicating or implying its relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0022] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0023] The embodiment of the present invention provides a method for accurately controlling the temperature of a hair straightener based on power regulation. Figure 1 , Figure 1 A flow chart of a method for accurately controlling the temperature of a hair straightener based on power regulation provided by an embodiment of the present invention. The method comprises the following steps: S101, after the heating plate detects a switch command, the heating plate heats to a preset working temperature with a preset working power.

[0024] S102, obtaining the working residual temperature of the heating plate during the use cycle, fitting a temperature drop curve according to the preset working temperature and the working residual temperature, and determining the slope of the temperature drop curve.

[0025] S103, after the first cycle, determining the hair quality of the user according to the slope of the curve, and adjusting the working power of the hair straightener according to the hair quality of the user.

[0026] The temperature corresponding to each moment in the use cycle is the working residual temperature.

[0027] A hair straightener temperature precision control method based on power adjustment provided by an embodiment of the present invention automatically adjusts the temperature according to the user's hair quality, reducing the problem of manual adjustment that reduces the user experience. By intelligently detecting the residual temperature of the heating plate and fitting the temperature drop curve, the user's hair quality is automatically judged, and then the working power of the hair straightener is adaptively adjusted, realizing a personalized and intelligent heating experience, greatly improving the convenience and satisfaction of users.

[0028] In one implementation, the heating plate receives a switch command, which means that the user presses a start button of the hair straightener, so that the heating plate receives a heating command and starts working, and the heating plate is heated to a preset working temperature, for example: the preset working temperature may be 180 degrees Celsius; the straightening action refers to the action of the user straightening his hair using a hair straightener.

[0029] In one implementation, each cycle includes a heating cycle and a use cycle. The heating cycle is a cycle corresponding to a preset working temperature at a preset working power after the heating plate detects a switch command. The use cycle is a complete cycle of the residual working temperature of the hair straightener: the moment when the hair straightener is heated to the preset working temperature is taken as the starting moment. When the hair straightener detects that it is not clamping hair through a pressure sensor, it is determined that the first cycle ends. At this time, the moment when the first cycle ends is the end moment of the residual working temperature of the hair straightener, wherein the temperature at each moment in the use cycle is referred to as the residual working temperature. The residual working temperature of the heating plate in the use cycle is obtained. After the first cycle, the user will make a hair quality judgment when using the hair straightener, but will not make a judgment in subsequent cycles. When all cycles are completed, that is, the user will use the hair straightener again and the hair quality judgment will be made again.

[0030] In one implementation, fine and soft hair has a small diameter, soft texture, and relatively loose hair scales, which causes the fine and soft hair to absorb heat relatively quickly. When using a hair straightener, the fine and soft hair will take away the heat from the hair straightener faster; coarse and hard hair has a large diameter, hard texture, and tight hair scales, which causes the coarse and hard hair to absorb heat relatively slowly. Because its larger diameter and tight hair scale structure make it more difficult for heat to penetrate into the hair, the temperature of the hair straightener is therefore lost more slowly; normal hair has a moderate diameter, healthy texture, and neatly arranged hair scales, and absorbs heat relatively evenly, being neither too sensitive nor too slow.

[0031] In one embodiment, step S102 includes: Real-time sampling is performed on the heating plate during its use cycle to obtain a key point set, and the key points in the key point set are arranged in time series and fitted to obtain a temperature drop curve.

[0032] The temperature drop curve is divided into a curve segment set according to a preset interval, and the absolute mean value of the curve slope is calculated according to the curve segment set to obtain the curve slope.

[0033] In one implementation, real-time sampling, for example: if the time from the beginning to the end of ironing by a user using a hair straightener is twenty seconds, real-time sampling is to collect temperature data every one second; the temperature drop curve is divided according to a preset interval to obtain a curve segment set, for example: the temperature drop curve is segmented according to a preset interval, that is, it is segmented once per second, and the segment interval can also be adjusted according to the actual length of the temperature drop curve; the method of taking the average slope of the segments improves the accuracy and robustness of data processing by dividing the curve into multiple small segments, and calculating the slope on each segment and then taking the average value, so that the result can better reflect the overall change trend of the curve, while facilitating subsequent analysis and being able to flexibly adapt to the needs of different accuracy.

[0034] In one implementation, the slope of the curve is obtained by calculating the absolute mean of the slope of the curve based on the set of curve segments, where the absolute mean means, for example: in the set (-1, -2, -3), firstly converting each element in the set to an absolute value, that is, taking the opposite of the negative number, to obtain the set (1, 2, 3), and then taking the average of each element in the set (1, 2, 3) to obtain the average value 2.

[0035] In one embodiment, step S102 further includes: Get the line segment data in the curve segment set, and calculate the line segment data through the judgment formula to get the curve slope.

[0036]

[0037] Among them, F is the slope of the temperature drop curve, j is the number of line segment data in the curve segment concentration, is the slope of the line segment data in the curve segment set.

[0038] In one implementation, the temperature absorption rate of hair varies depending on the hair quality, resulting in different heat losses of the heating plate. Therefore, the slope of the temperature drop curve can well reflect the actual hair quality of the user, which is helpful in laying the foundation for subsequent analysis or operations.

[0039] In one embodiment, step S103 includes: Determine the user's hair quality based on the slope of the curve.

[0040] If the slope of the curve is greater than the upper threshold of the judgment interval, the user is judged to have fine and soft hair.

[0041] If the slope of the curve is within the judgment interval, it is judged that the user has normal hair quality.

[0042] If the slope of the curve is less than the lower threshold of the judgment interval, the user is judged to have coarse and hard hair.

[0043] In one implementation, a judgment interval, for example, interval [3, 5], if the curve slope is within the judgment interval, it means that the curve slope can be 3 or 5. In the interval [3, 5], both are within the judgment interval. If the curve slope is greater than the upper threshold, it means that the curve slope is greater than 5 and not equal to 5. Similarly, if the curve slope is less than the lower threshold, it means that the curve slope is less than 3 and not equal to 3.

[0044] In one embodiment, step S103 further includes: If the user has coarse and hard hair, the operating frequency and the operating power of the heating plate are reduced and the working cycle time of the heating plate is increased so that the temperature of the heating plate is maintained at the preset working temperature during the working cycle.

[0045] If the user has normal hair, the operating frequency, operating power and operating cycle time of the heating plate are maintained so that the operating temperature of the heating plate is at a preset operating temperature.

[0046] If the user has fine and soft hair, the operating frequency and operating power of the heating plate are increased and the operating cycle time of the heating plate is reduced so that the temperature of the heating plate is maintained at a preset operating temperature during the operating cycle.

[0047] In one implementation, the operation of the heating plate can be divided into multiple working cycles, each cycle includes a complete straightening action. The working cycle of the heating plate refers to: the time period from the user starting to straighten the hair to the first let down is a working cycle. Due to different hair qualities, the speed of temperature loss of the heating plate is different, so the working cycle time is also different. It is necessary to dynamically adjust the corresponding working cycle time and redetermine the working frequency accordingly; the working power reflects the amount of heat output by the heating plate per unit time, and the working frequency reflects the number of times the heating plate is heated per unit time. For example: the normal power of the heating plate is 25 watts, and increasing the power is to increase the power of the heating plate to 40 watts.

[0048] In one implementation, the preset working temperature of the hair straightener can be manually modified. The hair straightener also includes a monitoring module. When the user does not use it for a long time, the power of the heating plate will be reduced until it is completely turned off. When the heating plate is in an idle state, that is, the user's idle period, for example: the user is changing the area where the hair needs to be straightened, the heating plate will not immediately work and heat to the preset working temperature. It will only heat in real time when the hair is being straightened. The hair straightener also has overheating protection to prevent the temperature from being too high.

[0049] Based on the same inventive concept, the present invention also provides a device for accurately controlling the temperature of a hair straightener based on power regulation. Figure 2 , Figure 2A schematic diagram of a structure of a hair straightener temperature precision control device based on power regulation provided by an embodiment of the present invention, comprising: a command sending module, a slope calculation module and a temperature control module: The instruction sending module is used to heat the heating plate to a preset working temperature with a preset working power after the heating plate detects a switch instruction.

[0050] The slope acquisition module is used to obtain the working residual temperature of the heating plate during the use cycle, obtain the temperature drop curve according to the preset working temperature and the working residual temperature, and determine the slope of the temperature drop curve; the temperature corresponding to each moment in the use cycle is the working residual temperature.

[0051] The temperature control module is used to determine the user's hair quality according to the slope of the curve after the first cycle, and adjust the working power of the hair straightener according to the user's hair quality.

[0052] In one embodiment, the slope acquisition module includes: a curve fitting module and a slope division module: The curve fitting module is used to obtain a key point set by real-time sampling of the heating plate during its use cycle, arrange the key points in the key point set in time series and fit them to obtain a temperature drop curve.

[0053] The slope division module is used to divide the temperature drop curve into a set of curve segments according to a preset interval, and calculate the absolute mean value of the curve slope according to the curve segment set to obtain the curve slope.

[0054] In one embodiment, the slope division module further includes: a slope calculation module: The slope calculation module is used to obtain the line segment data in the curve segment set, and calculate the line segment data through a judgment formula to obtain the slope of the curve.

[0055]

[0056] Among them, F is the slope of the temperature drop curve, j is the number of line segment data in the curve segment concentration, is the slope of the line segment data in the curve segment set.

[0057] In one embodiment, the temperature control module includes: a hair quality determination module, a first hair quality module, a second hair quality module and a third hair quality module: The hair quality judgment module is used to judge the user's hair quality based on the slope of the curve.

[0058] The first hair quality module is used to determine that the user has fine and soft hair if the slope of the curve is greater than the upper threshold of the judgment interval.

[0059] The second hair quality module is used to determine that the user has normal hair quality if the slope of the curve is within the judgment interval.

[0060] The third hair quality module is used to determine that the user has coarse and hard hair if the slope of the curve is less than the lower limit threshold of the judgment interval.

[0061] In one embodiment, the temperature control module further includes: a first control module, a second control module and a third control module: The first control module is used to reduce the working frequency and working power of the heating plate and increase the working cycle time of the heating plate if the user has coarse and hard hair, so that the temperature of the heating plate is maintained at a preset working temperature during the working cycle.

[0062] The second control module is used to maintain the working frequency, working power and working cycle time of the heating plate if the user has normal hair quality, so that the working temperature of the heating plate is at a preset working temperature.

[0063] The third control module is used to increase the working frequency and working power of the heating plate and reduce the working cycle time of the heating plate if the user has fine and soft hair, so that the temperature of the heating plate is maintained at a preset working temperature during the working cycle.

[0064] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for precise temperature control of a hair straightener based on power regulation, characterized in that: The operation of the heating plate can be divided into multiple working cycles, each cycle includes a complete clamping straightening action, and each cycle includes a heating cycle and a use cycle. The method includes: After the heating plate detects the switch command, the heating plate is heated to a preset working temperature with a preset working power; Obtaining the working residual temperature of the heating plate during the use cycle, fitting a temperature drop curve according to the preset working temperature and the working residual temperature, and determining the slope of the temperature drop curve; the temperature corresponding to each moment in the use cycle is the working residual temperature; After the first cycle, the hair quality of the user is determined according to the slope of the curve, and the working power of the hair straightener is adjusted according to the hair quality of the user.

2. A hair straightener temperature precision control method based on power regulation according to claim 1, characterized in that: Determining the slope of the temperature drop curve includes: Real-time sampling is performed on the heating plate during its use period to obtain a key point set, and the key points in the key point set are arranged in time series and fitted to obtain a temperature drop curve; The temperature drop curve is divided into a curve segment set according to a preset interval, and the absolute mean value of the curve slope is calculated according to the curve segment set to obtain the curve slope.

3. A hair straightener temperature precision control method based on power regulation according to claim 2, characterized in that: The absolute mean value of the curve slope is calculated according to the curve segment set to obtain the curve slope, which includes: Acquire line segment data in the curve segment set, and calculate the line segment data using a judgment formula to obtain a curve slope; Among them, F is the slope of the curve, j is the number of line segment data in the curve segment set, is the slope of the line segment data in the curve segment set.

4. The method for precise temperature control of a hair straightener based on power regulation according to claim 1, characterized in that: Determining the hair quality of the user according to the slope of the curve includes: judging the user's hair quality according to the slope of the curve; If the slope of the curve is greater than the upper threshold of the judgment interval, the user is judged to have fine and soft hair; If the slope of the curve is within the judgment interval, it is judged that the user has normal hair quality; If the slope of the curve is less than the lower threshold of the judgment interval, it is determined that the user has coarse and hard hair.

5. The method for precise temperature control of a hair straightener based on power regulation according to claim 1, characterized in that: Adjusting the working power of the hair straightener according to the hair quality of the user comprises: If the user has coarse and hard hair, the operating frequency and the operating power of the heating plate are reduced and the working cycle time of the heating plate is increased so that the temperature of the heating plate is maintained at the preset working temperature during the working cycle; If the user has normal hair quality, the operating frequency, operating power and operating cycle time of the heating plate are maintained so that the operating temperature of the heating plate is at the preset operating temperature; If the user has fine and soft hair, the operating frequency and the operating power of the heating plate are increased and the working cycle time of the heating plate is reduced so that the temperature of the heating plate is maintained at the preset working temperature during the working cycle.

6. A device for accurately controlling the temperature of a hair straightener based on power regulation, characterized in that: The device comprises: an instruction sending module, a slope calculation module and a temperature control module: The instruction sending module is used to heat the heating plate to a preset working temperature with a preset working power after the heating plate detects a switch instruction; The slope acquisition module is used to acquire the working residual temperature of the heating plate during the use cycle, obtain a temperature drop curve according to the preset working temperature and the working residual temperature, and determine the slope of the temperature drop curve; the temperature corresponding to each moment in the use cycle is the working residual temperature; The temperature control module is used to determine the hair quality of the user according to the slope of the curve after the first cycle, and adjust the working power of the hair straightener according to the hair quality of the user.

7. The device for precise temperature control of a hair straightener based on power regulation according to claim 6, characterized in that: The slope acquisition module includes: a curve fitting module and a slope division module: The curve fitting module is used to obtain a key point set by real-time sampling of the heating plate during its use period, arrange the key points in the key point set in a time series and perform fitting to obtain a temperature drop curve; The slope division module is used to divide the temperature drop curve into a set of curve segments according to preset intervals, and calculate the absolute mean value of the curve slope according to the set of curve segments to obtain the curve slope.

8. The device for precise temperature control of a hair straightener based on power regulation according to claim 7, characterized in that: The slope division module also includes: a slope calculation module: The slope calculation module is used to obtain line segment data in the curve segment set, and calculate the line segment data through a judgment formula to obtain the curve slope; Among them, F is the slope of the temperature drop curve, j is the number of line segment data in the curve segment concentration, is the slope of the line segment data in the curve segment set.

9. The device for precise temperature control of a hair straightener based on power regulation according to claim 6, characterized in that: The temperature control module includes: a hair quality judgment module, a first hair quality module, a second hair quality module and a third hair quality module: The hair quality judgment module is used to judge the hair quality of the user according to the slope of the curve; The first hair quality module is used to determine that the user has fine and soft hair if the slope of the curve is greater than an upper threshold of the judgment interval; The second hair quality module is used to determine that the user has normal hair quality if the slope of the curve is within the judgment interval; The third hair quality module is used to determine that the user has coarse and hard hair if the slope of the curve is less than a lower threshold of the judgment interval.

10. The device for precise temperature control of a hair straightener based on power regulation according to claim 6, characterized in that: The temperature control module further includes: a first control module, a second control module and a third control module: The first control module is used for reducing the working frequency and working power of the heating plate and increasing the working cycle time of the heating plate if the user has coarse and hard hair, so that the temperature of the heating plate is maintained at the preset working temperature during the working cycle; The second control module is used for maintaining the working frequency, working power and working cycle time of the heating plate if the user has normal hair quality, so that the working temperature of the heating plate is at the preset working temperature; The third control module is used to increase the working frequency and working power of the heating plate and reduce the working cycle time of the heating plate if the user has fine and soft hair, so that the temperature of the heating plate is maintained at the preset working temperature during the working cycle.

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