Aerosol generating device and control method therefor

Abstract

An aerosol generating device and a control method therefor. An embodiment comprises: entering a preheating operational stage after receiving an initiate heating instruction (S11), wherein the preheating operational stage sequentially comprises a heat-up stage, a heat transfer sustaining stage, and a heat retention stage; during the heat-up stage, providing power to raise the temperature of a heater (103) (S12); during the heat transfer sustaining stage, providing power to maintain the heat transfer rate between the heater (103) and an aerosol forming substrate (S13); and during the heat retention stage, providing power to maintain the temperature of the heater (103) (S14), wherein the power provided to the heater (103) during the heat transfer sustaining stage is less than the power provided to the heater (103) during the heating stage, the problem of insufficient energy being absorbed by the aerosol forming substrate is prevented, and the smoking experience of the user is improved.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Chinese Patent Application No. 202211488305.2, filed with the China National Intellectual Property Administration on November 25, 2022 and entitled "AEROSOL GENERATING DEVICE AND CONTROL METHOD THEREFOR", which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] This application relates to the field of electronic atomization technologies, and in particular, to an aerosol generating device and a control method therefor.BACKGROUND

[0003] During the use of objects such as cigarettes or cigars, tobaccos are burnt to generate tobacco vapor. Attempts have been made to provide substitutes for these tobacco-burning objects by producing products that release compounds without burning. An example of such products is a heat-not-burn product, also referred to a tobacco heating product or a tobacco heating apparatus. The product or apparatus releases compounds by heating materials rather than burning materials. For example, the materials may be tobaccos or other non-tobacco products or combinations, for example, a blended mixture that may contain or not contain nicotine.

[0004] Existing aerosol generating devices require a temperature sensor of a heater to monitor a real-time temperature of the heater and perform power control according to a preset temperature curve during a preheating operational stage. During rapid heat-up of the heater, once the temperature reaches a preset maximum temperature, output power to the heater is immediately stopped to prevent temperature overshoot, thereby ensuring that the temperature of the heater conforms to a preheating temperature curve.SUMMARY

[0005] An aspect of this application provides a control method for an aerosol generating device. The aerosol generating device includes a heater configured to heat an aerosol forming substrate to generate an aerosol and a power source providing energy to the heater. The method includes: entering a preheating operational stage after receiving a heating initiation instruction, where the preheating operational stage sequentially includes a heat-up stage, a heat transfer sustaining stage, and a heat retention stage; providing power during the heat-up stage to significantly raise a temperature of the heater; providing power during the heat transfer sustaining stage to maintain a heat transfer rate between the heater and the aerosol forming substrate; and providing power during the heat retention stage to maintain the temperature of the heater, where the power provided to the heater during the heat transfer sustaining stage is less than the power provided to the heater during the heat-up stage.

[0006] Another aspect of this application provides a control method for an aerosol generating device. The aerosol generating device includes a heater configured to heat an aerosol forming substrate to generate an aerosol and a power source providing energy to the heater. The method includes: entering a preheating operational stage after receiving a heating initiation instruction, where the preheating operational stage includes a continuous output stage and an intermittent output stage; providing power during the continuous output stage to significantly raise a temperature of the heater; providing power during the intermittent output stage to maintain the temperature of the heater, where the power provided to the heater is decreased at least once within a time period of the continuous output stage.

[0007] Another aspect of this application provides an aerosol generating device, including: a heater, configured to heat an aerosol forming substrate to generate an aerosol; a power source, configured to provide energy to the heater; and a controller, configured to: in a preheating operational stage that sequentially includes a heat-up stage, a heat transfer sustaining stage, and a heat retention stage, provide power during the heat-up stage to significantly raise a temperature of the heater; provide power during the heat transfer sustaining stage to maintain a heat transfer rate between the heater and the aerosol forming substrate; and provide power during the heat retention stage to maintain the temperature of the heater, where the power provided to the heater during the heat transfer sustaining stage is less than the power provided to the heater during the heat-up stage.

[0008] Another aspect of this application provides an aerosol generating device, including: a heater, configured to heat an aerosol forming substrate to generate an aerosol; a power source, configured to provide energy to the heater; and a controller, configured to: in a preheating operational stage including a continuous output stage and an intermittent output stage, provide power during the continuous output stage to significantly raise a temperature of the heater, and provide power during the intermittent output stage to maintain the temperature of the heater, where the power provided to the heater is decreased at least once during the continuous output stage.

[0009] In the aerosol generating device and the control method therefor provided in this application, during the preheating operational stage, the heat-up stage, the heat transfer sustaining stage, and the heat retention stage are sequentially set, especially, the heat transfer sustaining stage is added after the heat-up stage, and a high-power output in the heat-up stage is immediately followed by a low-power output in the heat transfer sustaining stage, thereby facilitating the absorption of sufficient heat by the aerosol forming substrate in the preheating stage and optimizing the taste of the first puff of vapor.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] One or more embodiments are exemplarily described with reference to the corresponding figures in the accompanying drawings, and the descriptions do not constitute a limitation to the embodiments. Components in the accompanying drawings that have same reference numerals are represented as similar components, and unless otherwise particularly stated, the figures in the accompanying drawings are not drawn to scale. FIG. 1 is a schematic structural diagram of an aerosol generating article according to an embodiment of this application; FIG. 2 is a schematic structural diagram of an aerosol generating device according to an embodiment of this application; FIG. 3 is a schematic diagram of a control method for an aerosol generating device according to an embodiment of this application; FIG. 4 is a schematic diagram of a control method for an aerosol generating device according to an embodiment of this application; FIG. 5 is a schematic diagram of a supply voltage curve of a heater according to an embodiment of this application; FIG. 6 is a schematic diagram of a supply voltage curve of a heater according to an embodiment of this application; FIG. 7 is a schematic diagram of a supply voltage curve of a heater according to an embodiment of this application; FIG. 8 is a schematic diagram of a supply voltage curve of a heater according to an embodiment of this application; and FIG. 9 is a schematic diagram of a real-time temperature curve of a heater according to an embodiment of this application. DETAILED DESCRIPTION

[0011] For ease of understanding of this application, this application is described in further detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, when an element is expressed as "being fixed to" another element, the element may be directly on the another element, or one or more intermediate elements may exist between the element and the another element. When an element is expressed as "being connected to" another element, the element may be directly connected to the another element, or one or more intermediate elements may exist between the element and the another element. The terms "upper", "lower", "left", "right", "inside", "outside" and similar expressions used in this specification are merely used for an illustrative purpose.

[0012] Unless otherwise defined, meanings of all technical and scientific terms used in this specification are the same as those usually understood by a person skilled in art of this application. Terms used in this specification of this application are merely intended to describe objectives of the specific embodiments, and are not intended to limit this application. The term "and / or" used in this specification includes any or all combinations of one or more related listed items.

[0013] The accompanying drawings may only show elements related to this embodiment. A person skilled in the art should understand that the accompanying drawings may further include other common elements in addition to elements shown in the accompanying drawings.

[0014] FIG. 1 is a schematic structural diagram of an aerosol generating article according to an embodiment of this application.

[0015] As shown in FIG. 1, an aerosol generating article 20 includes a filter segment 21 and a substrate segment 22.

[0016] The substrate segment 22 includes an aerosol forming substrate. The aerosol forming substrate is a substrate that can release volatile compounds forming aerosols, and the volatile compounds can be released by heating the aerosol forming substrate.

[0017] The aerosol forming substrate may be a solid aerosol forming substrate. Alternatively, the solid aerosol forming substrate may include solid and liquid components. The aerosol forming substrate may include a tobacco-containing material, which contains volatile tobacco-flavor compounds that are released from the aerosol-forming substrate when the aerosol-forming substrate is heated. Alternatively, the aerosol forming substrate may include a non-tobacco material. The aerosol forming substrate may further include an aerosol forming substance. An example of an appropriate aerosol forming substance is glycerin and propanediol.

[0018] An aerosol generated by heating the substrate segment 22 is conveyed to a user through the filter segment 21. The filter segment 21 may be a cellulose acetate filter. A flavoring liquid may be sprayed on the filter segment 21 to provide a flavor or separate fiber coated with a flavoring liquid may be inserted into the filter segment 21, thereby enhancing the persistence of the taste conveyed to the user. The filter segment 21 may be further provided with a spherical or cylindrical capsule. The capsule may hold a core containing a flavorant.

[0019] The aerosol generating article 20 may further include a cooling segment 23 that is disposed between the substrate segment 22 and the filter segment 21 and configured to cool the aerosol generated when the substrate segment 22 is heated, to allow the user to inhale the aerosol that is cooled to an optimal temperature.

[0020] FIG. 2 is a schematic structural diagram of an aerosol generating device according to an embodiment of this application.

[0021] As shown in FIG. 1 and FIG. 2, the aerosol generating device 10 includes a battery cell 101, a controller 102, and a heater 103. In addition, the aerosol generating device 10 is provided with an internal space defined by a housing. The aerosol generating article 20 may be inserted into the internal space of the aerosol generating device 10.

[0022] The battery cell 101, i.e., a power source, is configured to provide electric power for operating the aerosol generating device 10. For example, the battery cell 101 may provide electric power to heat the heater 103, and may provide electric power required for operating the controller 102. In addition, the battery cell 101 may provide electric power required for operating a display device, a sensor, a motor, and the like provided in the aerosol generating device 10.

[0023] The battery cell 101 may be, but is not limited to, a lithium iron phosphate (LiFePO 4 ) battery. For example, the battery cell 101 may be alternatively a lithium cobaltate (LiCoO 2 ) battery or a lithium titanate battery. The battery cell 101 may be alternatively a rechargeable battery or a disposable battery.

[0024] When the aerosol generating article 20 is inserted inside the aerosol generating device 10, through the electric power provided by the battery cell 101, the aerosol generating device 10 may heat the heater 103. The heater 103 enables the temperature of the aerosol forming substrate in the aerosol generating article 20 to generate an aerosol. The generated aerosol is transferred to the user through the filter segment 21 of the aerosol generating article 20 for vaping.

[0025] The heater 103 and the aerosol forming substrate may use various heating coupling configurations. For example, the heater 103 may use a center-heating type. The heater 103 has configurations such as a needle, a sheet, and a pin, and is inserted inside the aerosol forming substrate to enable a periphery of the heater 103 be in contact with or in immediate proximity to (as close as practicable to) the aerosol forming substrate, thereby implementing the transfer of heat. The heater 103 may use a peripheral-heating type. The heater 103 is usually a hollow cylinder, and the aerosol forming substrate is disposed inside the hollow cylinder of the heater 103 to enable an inner wall of the heater 103 to be in contact with or in immediate proximity to (as close as practicable to) a circumference of the aerosol forming substrate, thereby implementing the transfer of heat.

[0026] The heater 103 may use various heating manners. For example, the aerosol forming substrate is heated in one or more manners of resistive heating, electromagnetic induction, chemical reaction, infrared radiation, resonance, photoelectric conversion, photothermal conversion, and air heating.

[0027] The controller 102 may control the operation of main components in the aerosol generating device 10. Specifically, the controller 102 may control the operation of the battery cell 101 and the heater 103, and may further control the operation of other components in the aerosol generating device 10.

[0028] The controller 102 is further configured to perform a control method for the aerosol generating device 10.

[0029] The controller 102 includes at least one processor. The controller 102 may include a logic gate array, or may include a combination of a general-purpose microprocessor and a memory that stores programs executable in the microprocessor.

[0030] For example, the controller 102 controls the operation of the heater 103. The controller 102 may control an amount of electric power provided to the heater 103, a period of continuously providing electric power to the heater 103, and stop providing power to the heater 103. In addition, the controller 102 may further monitor the status (e.g., the remaining battery capacity of the battery cell 101) of the battery cell 101, and / or monitor the operating status (e.g., a resistance change of the heater 103) of the heater 103, and may generate a notification signal if necessary to notify the user.

[0031] In addition to the battery cell 101, the controller 102, and the heater 103, the aerosol generating device 10 may further include other general-purpose components. For example, the aerosol generating device 10 may include a display device configured to output visual information. The display device may be visual display components such as a display, a touchscreen, a lighting assembly, or the like. The controller 102 may send, to the user, information (e.g., whether the aerosol generating device 10 is available for use) about the status of the aerosol generating device 10, information (e.g., preheating started, preheating in progress, or preheating completed) about the heater 103, information (e.g., the remaining battery capacity of the battery cell 101 and whether the battery cell 101 is available for use) about the battery cell 101, information (e.g., reset timing, reset in progress, or reset completed) about reset of the aerosol generating device 10, information (e.g., cleaning time, cleaning required, cleaning in progress, or cleaning completed) about cleaning of the aerosol generating device 10, information (e.g., charging required, charging in progress, or charging completed) about charging of the aerosol generating device 10, information (e.g., a vaping count and a vaping termination notice) about vaping, and information (e.g., use time) about safety. For example, the aerosol generating device 10 may further include a vibration motor configured to output haptic feedback information. The controller 102 may generate a vibration feedback signal by using the vibration motor and send the information to the user. For example, the aerosol generating device 10 further includes an airflow sensor configured to detect whether the user is vaping and / or the intensity of vaping. For example, the aerosol generating device 10 may include at least one input apparatus to control the functions of the aerosol generating device 10. Specifically, the input apparatus may include buttons, a touchscreen, or the like. The user may perform various functions by using the input apparatus. For example, the number of times (e.g., once or twice) that the user presses the input apparatus or the time (e.g., 0.1 seconds or 0.2 seconds) for which the user presses the input apparatus is adjusted to perform a desired function among multiple functions of the aerosol generating device 10. In addition, the user may use the input apparatus to perform the function of heating by the heater 103, the function of adjusting the temperature of the heater 103, the function of cleaning the space for inserting the aerosol generating article 20, the function of checking whether the aerosol generating device 10 is operable, the function of displaying the remaining battery capacity (available electric power) of the battery cell 101, or the function of resetting the aerosol generating device 10. However, the functions of the aerosol generating device 10 are not limited thereto.

[0032] In some embodiments, the aerosol generating device 10 further includes the voltage regulation circuit coupled between the heater 103 and the battery cell 101. The voltage regulation circuit includes a boost circuit and / or a buck circuit, for example, a BUCK-BOOST converter circuit shown in FIG. 5. It should be understood that the voltage regulation circuit is not limited to a BUCK-BOOST converter circuit, and may be alternatively at least one of a BOOST converter circuit, a BUCK converter circuit, a CUK converter circuit, a ZETA converter circuit, and a SEPIC converter circuit.

[0033] In some embodiments, the temperature of the heater 103 may be measured by arranging a temperature sensor on or near the heater 103 or directly set. For example, a thermal couple, a thermistor, or a phase-change material is used for temperature measurement. Alternatively, in some embodiments, the temperature of the heater 103 may be directly measured or set by measuring and setting the resistance of the heater 103. For example, a TCR temperature measurement is used.

[0034] FIG. 3 is a flowchart of a control method for an aerosol generating device according to an embodiment of this application. As shown in FIG. 3, the controller 102 is configured to perform a control method for the aerosol generating device 10. The method includes the following steps.

[0035] Step S11: After a heating initiation instruction is received, enter a preheating operational stage.

[0036] The heating initiation instruction may be a signal generated by the user operating an input element, or may be obtained relying on a detection signal of a sensor. For example, an engagement trigger signal is generated upon the insertion of the aerosol generating article 20 into the aerosol generating device 10 detected via a pressure sensor, an electrical parameter sensor, or the like, or a signal for initiation through vaping by the user is detected via the airflow sensor.

[0037] The preheating operational stage is an operational stage in which the temperature of the aerosol forming substrate is increased to a point at which a satisfying amount of aerosol is generated. The aerosol may be generated in this stage, but is usually not very likely to be sucked outside the aerosol generating device 10 by the user. When the preheating operational stage ends, the aerosol forming substrate may already reach a temperature at which volatile components that the aerosol forming substrate contains are released.

[0038] In the field of aerosol heating, the time of the first puff is a critical factor, as consumers generally do not wish to wait too long after device activation before taking the first puff. Therefore, there is a desire to minimize the duration of the preheating operational stage. However, the sensory experience of the first puff is also a critical factor, as consumers expect fully-developed flavor profiles without any "raw" taste, necessitating ensuring absorption of sufficient heat by the aerosol forming substrate to reach the temperature required for releasing volatile compounds that the aerosol forming substrate contains. Accordingly, this application aims to ensure absorption of sufficient heat by the aerosol forming substrate without extending the duration of the preheating operational stage.

[0039] Chronologically, the heat transfer sustaining stage is sequentially divided into three stages, namely, a heat-up stage, a heat transfer sustaining stage, and a heat retention stage. Step S12 to Step S14 are sequentially described below in the order of providing power by the controller 102.

[0040] Step S12: Provide power during the heat-up stage to significantly raise a temperature of the heater 103.

[0041] During the heat-up stage, the purpose of providing high power to the heater 103 by the controller 102 is to enable the heater 103 to heat up as quickly as possible from an initial temperature (typically 25°C in a cold state, i.e., ambient temperature) to a maximum temperature threshold T1. Supplied energy / power by the controller 102 during the heat-up stage is far greater than that during the heat transfer sustaining stage and that during the heat retention stage. The high power that can be provided in the heat-up stage is typically limited by factors such as maximum power that the power source and electronic elements can provide and the capacity of the power source. The "significantly" here may be understood as a temperature difference exceeding 100°C, preferably, exceeding 200°C. For example, the maximum temperature threshold approximately ranges from 260°C to 270°C.

[0042] In some embodiments, the power provided by the controller 102 may be a maximum real-time voltage U 0 that the battery cell 101 can provide. However, as the capacity of the battery cell attenuates, the real-time voltage supplied by the battery cell 101 to the heater 103 also decreases accordingly. In some embodiments, the power provided by the controller 102 may be alternatively stable power outputted through a voltage regulation circuit.

[0043] In some embodiments, the controller 102 may preset a supply amount of energy (referred to as set energy hereinafter) in the first power output stage. For example, an output voltage and a power supply period may further be set to reflect set energy. For example, the set energy may be indirectly reflected by only setting the power supply period in a case of stable output power. For example, only energy may be set, and both the output power and the power supply period are variable. In the heat-up stage, the controller 102 performs power output only based on set energy Q1 of the heat-up stage. When determining that the supplied energy meets the set energy Q1, the controller 102 stops the power output in the heat-up stage and simultaneously enters the heat transfer sustaining stage. A real-time temperature of the heater 103 does not need to be considered in the control of the entire heat-up stage. In some embodiments, the power output in the heat-up stage may be stopped and the heat transfer sustaining stage may be simultaneously entered by quantifying the power supply period in the heat-up stage and determining whether the power supply period meets a preset time threshold.

[0044] In some embodiments, the controller 102 may detect the real-time temperature of the heater 103 using the temperature sensor. During the heat-up stage, the controller 102 performs power output based on the maximum real-time voltage or a set stable voltage, during the power output, the real-time temperature of the heater 103 is monitored. When the real-time temperature reaches the preset maximum temperature threshold T1, the power output in the heat-up stage is stopped and the heat transfer sustaining stage is simultaneously entered.

[0045] In some embodiments, during the heat-up stage, a process in which the controller 102 provides power may be an uninterrupted continuous output. In this way, the requirement of rapid heat-up of the heater 103 can be met. In some embodiments, when providing power, the controller 102 can avoid temperature overshoot of the heater 103 during the heat-up stage by adjusting the duty cycle in at least part of the time.

[0046] Step S13: Provide power during the heat transfer sustaining stage to maintain a heat transfer rate between the heater 103 and the aerosol forming substrate.

[0047] The heat transfer rate herein may be understood as an amount of heat transferred through a thermal conduction cross-section between the heater 103 and the aerosol forming substrate per unit time. According to Fourier's Law, during heat conduction, an amount of heat transferred through a given cross-section per unit time is directly proportional to both a temperature gradient in a direction perpendicular to the cross-section and the area of the cross-section, whereas the direction of heat transfer is opposite to the direction of temperature increase. It can be concluded that the heat transfer rate is directly proportional to the temperature gradient when the area of the thermal conduction cross-section remains constant.

[0048] Generally, when the heater 103 reaches a maximum temperature, in this case, a temperature difference between the interior of the aerosol forming substrate and the heater 103 reaches its maximum, and the heat transfer rate between the aerosol forming substrate and the heater 103 reaches its maximum. If energy supply is stopped at this point, the real-time temperature of the heater 103 drops immediately, the temperature difference between the aerosol forming substrate and the heater 103 decreased, and the heat transfer rate between the heater 103 and the aerosol forming substrate also drops correspondingly. As a result, the rate at which the aerosol forming substrate absorbs heat is effected, leading to a "raw" taste in the first puff of vapor, or extending the preheating operational stage.

[0049] Therefore, in the embodiments of this application, the heat transfer sustaining stage is added after the heat-up stage, and a low-power output is provided in the heat transfer sustaining stage, so that the temperature difference between the heater 103 and the aerosol forming substrate is still maintained, and the aerosol forming substrate can absorb heat from the heater 103 at a high rate. If high power continues to be provided to the heater 103 in the heat transfer sustaining stage, the aerosol forming substrate may be overheated to cause a burnt state. Therefore, the power provided to the heater 103 during the heat transfer sustaining stage is less than the power provided to the heater 103 during the heat-up stage. For example, the power provided to the heater 103 during the heat-up stage is higher than 25 W, and preferably, higher than 30 W, whereas the power provided to the heater 103 during the heat transfer sustaining stage is approximately 8 W.

[0050] In some embodiments, when entering the heat transfer sustaining stage from the heat-up stage, the controller 102 controls the power source to uninterruptedly switch from the high power during the heat-up stage to low power for supply to the heater 103. It should also be understood that the transition between the heat-up stage and the heat transfer sustaining stage is an uninterrupted continuous output with no time gap.

[0051] As shown in FIG. 5 to FIG. 8, during the heat transfer sustaining stage, the power output of the controller 102 to the heater 103 may be a continuous output. Specifically, the power outputted by the controller 102 may be implemented in various manners.

[0052] For example, as shown in FIG. 5, the input voltage of the heater 103 decreases stepwise a plurality of times over time. The duration and / or decrease amplitude of each step voltage may be adjusted according to an actual requirement.

[0053] For example, as shown in FIG. 6, the input voltage of the heater 103 remains constant after decreasing once with respect to the input voltage in the heat-up stage.

[0054] For example, as shown in FIG. 7, the input voltage of the heater 103 decreases linearly, and may decrease with a constant slope, or decrease with a varying slope.

[0055] For example, as shown in FIG. 8, the input voltage of the heater 103 varies in a wave-like pattern over time. In other words, the input voltage of the heater 103 rises and drops during the heat transfer sustaining stage.

[0056] In some embodiments, the input voltage of the heater 103 may alternatively use a discrete pulse output. At least one of duration of a pulse and duration between pulses is variable. For example, the controller 102 may further adjust output power in the heat transfer sustaining stage by adjusting the duty cycle. An interval between a trigger time of an initial discrete pulse and an end time of the heat-up stage shall not exceed 3 s.

[0057] Duration (t 1 to t 11 ) of the heat transfer sustaining stage ranges from 2 s to 3 s. The duration is measured based on a heat transfer flux and transfer efficiency between the heater 103 and the aerosol forming substrate. This facilitates sufficient absorption of heat by the aerosol forming substrate.

[0058] In some embodiments, the controller 102 may preset a supply amount of energy (referred to as set energy hereinafter) in the heat transfer sustaining stage. For example, an output voltage and a power supply period may further be set to represent set energy. For example, as shown in FIG. 6, the set energy may be represented by only setting a voltage supply period in a case of a stable output voltage. For example, only energy may be set, and both the output power and the power supply period are variable. In the heat transfer sustaining stage, the controller 102 performs power output only based on set energy Q2 of the heat transfer sustaining stage. When determining that the supplied energy meets the set energy Q2, the controller 102 stops the power output and simultaneously enters the heat retention stage. The real-time temperature of the heater 103 does not need to be considered in the control of the entire heat transfer sustaining stage. In some embodiments, the controller 102 may quantify duration of the heat transfer sustaining stage, and when the duration meets a preset time threshold, stop the power output, end the heat transfer sustaining stage, and enter the heat retention stage.

[0059] In some embodiments, the controller 102 may detect the real-time temperature of the heater 103 using the temperature sensor. In the heat transfer sustaining stage, the real-time temperature of the heater 103 is monitored. When the real-time temperature reaches a preset temperature threshold (a target low-temperature threshold of the heater 103 in this stage), the power output is stopped, and the heat retention stage is simultaneously entered. When the real-time temperature reaches the preset temperature threshold (a target low-temperature threshold of the heater 103 in a different stage), the power supplied to the heater 103 may be changed. For example, in FIG. 8, the supply voltage fluctuates.

[0060] Step S14: Provide power during the heat retention stage to maintain the temperature of the heater 103.

[0061] In the heat retention stage, the purpose of providing power to the heater 103 by the controller 102 is to ensure that the aerosol forming substrate has enough time to continue to maintain heat transfer, thereby fully absorbing heat from the heater 103. However, in this stage, the heater 103 and the aerosol forming substrate also keep dissipating heat outside, causing heat losses. In this case, it is only necessary to compensate for the heat losses in a targeted manner to enable the heat transfer between the heater 103 and the aerosol forming substrate to continue instead of being interrupted. As seen from the temperature of the heater 103, the temperature in this stage may essentially remain constant, or fluctuate within a small temperature interval (approximately 2°C to 5°C), or uniformly drop within a small temperature interval (approximately 2°C to 5°C).

[0062] In some embodiments, the heat retention stage may be divided into a plurality of power output stages (intermittent outputs) for energy supply, thereby compensating for the heat loss of the heater 103. In each power output stage, the controller 102 outputs power to the heater 103 and maintains the output for a particular period (a power supply period). In this case, the temperature of the heater 103 slightly rises (less than 3°C), for example, t 21-1 in FIG. 9. When supplied energy (the output power*the power supply period) reaches a set value Q3, the controller 102 stops the power output. In addition, after the heater 103 naturally cools for a period of time, power output of a next power output stage is initiated. In this case, the temperature of the heater 103 slightly decreases (less than 3°C), for example, t 21-2 in FIG. 9. A power supply period of each power output stage is greater than or equal to 500 milliseconds (ms), and preferably, greater than 1 s, or the frequency is less than or equal to 2 Hz, and is different from PWM output control (the frequency is approximately 100 Hz), which is a high-frequency output.

[0063] Regarding when to end the natural cooldown period and initiate a power output of a next power output stage, this application provides several ideas. First, the real-time temperature of the heater 103 may be detected within the natural cooldown period, and when it is detected that the real-time temperature of the heater 103 reaches a set low temperature threshold, a next second power output stage is initiated. Second, duration of the natural cooldown period is quantified, and when the duration of the natural cooldown period meets a preset time threshold, a next power output stage is initiated. In the first manner, the reliance on the real-time temperature of the heater 103 is reduced, and it is only necessary to monitor the real-time temperature to ensure that the real-time temperature does not exceed the low-temperature threshold to implement control, and in the second manner, control can be implemented without monitoring the real-time temperature of the heater 103, thereby avoiding the impact on the precision of the temperature sensor. As seen from the changes in the real-time temperature of the heater 103, in the heat retention stage, the temperature of the heater 103 fluctuates. As seen from changes in the output power, the output is intermittent outputs.

[0064] A heater 103 with thick-film resistive heating in a circumferential configuration is used as an example. Because a thick-film resistive heater has characteristics of quick heat-up and weak heat retention performance, in the heat retention stage, the controller 102 sequentially initiates 3 to 5 power output stages. For each power output stage, output power is approximately 6 W, a power supply period is approximately 1 s (which may change based on real-time power), and a natural cooldown period is approximately 3 s.

[0065] A heater 103 with infrared heating in a circumferential configuration is used as an example. Because an infrared heater has characteristics of slow heat-up and good heat retention performance, in the heat retention stage, the controller 102 sequentially initiates 3 to 5 power output stages. For each power output stage, output power is approximately 6 W, a power supply period is approximately 1 s, and a natural cooldown period approximately ranges from 5 s to 8 s.

[0066] In some embodiments, a target temperature interval of the heater 103 in the heat retention stage may be preset, and it is determined, based on the target temperature interval, whether to provide power to the heater 103. For example, it is set that a target temperature range of the heater 103 in the heat retention stage is T1 to T2. When the real-time temperature of the heater 103 is less than the low-temperature threshold T2, power is outputted to the heater 103. When the real-time temperature of the heater 103 meets the low-temperature threshold T1, power output is stopped, and natural cooldown is entered. The real-time temperature of the heater 103 in this manner also demonstrates a fluctuating pattern within the target temperature range. However, the precision of temperature measurement of the heater 103 is relatively high.

[0067] In some embodiments, a target temperature of the heater 103 in the heat retention stage may be preset, and a voltage is supplied from the power source to the heater 103 in a discrete pulse manner. At least one of duration of a pulse and duration between pulses is variable. That is, the controller 102 may adjust the output power of the heater 103 by adjusting the duty cycle of the output voltage, to enable the heater 103 in the heat retention stage maintain the target temperature. The duration of the pulse may range from 500 microseconds (µs) to 1 milliseconds (ms), which is a high-frequency output.

[0068] FIG. 4 is a flowchart of a control method for an aerosol generating device according to an embodiment of this application. As shown in FIG. 4, the controller 102 is configured to perform a control method for the aerosol generating device 10. The method includes the following steps.

[0069] Step S21: After a heating initiation instruction is received, enter a preheating operational stage.

[0070] As divided from the form of the output power, the preheating operational stage may be sequentially divided into two stages, which are a continuous output stage and an intermittent output stage.

[0071] Step S22: Provide power during the continuous output stage to significantly raise the temperature of the heater 103, where output power in the continuous output stage is decreased at least once

[0072] The continuous output stage includes the heat-up stage and the heat transfer sustaining stage described above. The purpose of the output power of the continuous output stage is to enable the heater 103 to significantly rise from the initial temperature to the target maximum temperature threshold, for example, rise from 25°C in a cold state to more than 260°C. The "significantly" here may be understood as a temperature difference exceeding 100°C, preferably, exceeding 200°C. For example, the maximum temperature threshold approximately ranges from 260°C to 270°C. The continuous output of power facilitates as quick heat-up as possible of the heater 103. For example, a resistive circumferential heater 103 can implement significant heat-up within 10 s. For example, an infrared circumferential heater 103 can implement the foregoing significant heat-up within 17 s.

[0073] In this stage, in addition to considering significant heat-up, when the heater 103 reaches or approaches the target maximum temperature threshold, a high-power output further needs to be switched to a low-power output, and the output is an uninterrupted output. This facilitates maintenance of the heat transfer rate between the heater 103 and the aerosol forming substrate, so that the aerosol forming substrate can use this the heat transfer rate to absorb heat more quickly. For example, duration of the low-power output approximately ranges from 2 s to 3 s.

[0074] High power may be reduced to high power in various manners, for example, decrease stepwise once and remain constant; for example, decrease stepwise a plurality of times; for example, decrease linearly with a single slope; for example, decrease linearly with a varying slope; and for example, decrease in a fluctuating manner.

[0075] Step S23: Provide power during the intermittent output stage to maintain the temperature of the heater 103.

[0076] In the late phase of the preheating operational stage, in this case, it is only necessary to keep the temperature of the heater 103, and it is only necessary to compensate for the heat loss of the heater 103 in an intermittent manner to keep the heat transfer between the heater 103 and the aerosol forming substrate from being interrupted. Duration of the intermittent output stage approximately ranges from 4 s to 8 s.

[0077] In some embodiments, the intermittent output stage may be implemented in a regular output manner of constant energy in the foregoing embodiments, so that the reliance on the real-time temperature of the heater 103 can be reduced or omitted. In this way, the problem of insufficient heat absorption of the aerosol forming substrate caused by the setting or precision degree of the temperature sensor can be avoided. For this manner of intermittently outputting power with constant energy, each power output period is greater than or equal to 500 ms, and an output is a low-frequency output.

[0078] In some embodiments, in the intermittent output stage, a voltage may be supplied from the power source to the heater 103 in a discrete pulse manner. The duration of the pulse may range from 500 µs to 1 ms, which is a high-frequency output.

[0079] In some embodiments, a controller 102 is provided, including a memory and a processor. The memory stores a computer program. The processor, when executing the computer program, implements the steps of the control method for an aerosol generating device in any foregoing method embodiment.

[0080] In some embodiments, a computer-readable storage medium is provided, having a computer program stored thereon. The computer program, when executed by a processor, implements all or some of the procedures in the control method for an aerosol generating device of the foregoing embodiments. The procedures may be implemented, by a computer program instructing relevant hardware. The computer program may be stored in a non-volatile computer-readable storage medium. The computer program is executed to perform the procedures in the foregoing embodiments of the methods. Any usage of a memory, storage, a database or another medium in the embodiments provided in this application may include at least one of non-volatile and volatile memories. The non-volatile memory may include a read-only memory (ROM), a magnetic tape, a floppy disk, a flash memory, an optical memory, or the like. The volatile memory may include a random access memory (RAM) or an external cache. By way of illustration and not limitation, the RAM may take various forms such as a static random access memory (SRAM) or a dynamic random access memory (DRAM).

[0081] It should be noted that the specification of this application and the accompanying drawings thereof illustrate preferred embodiments of this application. However, this application may be implemented in various different forms, and is not limited to the embodiments described in this specification. These embodiments are not intended to be an additional limitation on the content of this application, and are described for the purpose of providing a more thorough and comprehensive understanding of the content disclosed in this application. Moreover, the above technical features may further be combined to form various embodiments not listed above, and all such embodiments shall be construed as falling within the scope of the specification of this application. Further, a person of ordinary skill in the art may make improvements and variations according to the above descriptions, and such improvements and variations shall all fall within the protection scope of the appended claims of this application.

Claims

1. A control method for an aerosol generating device, the aerosol generating device comprising a heater configured to heat an aerosol forming substrate to generate an aerosol and a power source providing energy to the heater, wherein the method comprises: entering a preheating operational stage after receiving a heating initiation instruction, wherein the preheating operational stage sequentially comprises a heat-up stage, a heat transfer sustaining stage, and a heat retention stage; providing power during the heat-up stage to significantly raise a temperature of the heater; providing power during the heat transfer sustaining stage to maintain a heat transfer rate between the heater and the aerosol forming substrate; and providing power during the heat retention stage to maintain the temperature of the heater, wherein the power provided to the heater during the heat transfer sustaining stage is less than the power provided to the heater during the heat-up stage.

2. The control method according to claim 1, wherein power is uninterruptedly provided between the heat-up stage and the heat transfer sustaining stage.

3. The control method according to claim 2, wherein during the heat transfer sustaining stage, a voltage provided by the power source to the heater is controlled to change based on at least one of the following cases: decreasing stepwise over time; decreasing linearly over time; and varying in a wave-like pattern over time.

4. The control method according to claim 1, wherein the providing power during the heat transfer sustaining stage comprises: providing the power in a pulsed manner during the heat transfer sustaining stage, wherein an interval between a trigger time of an initial pulse and an end time of the heat-up stage does not exceed 3 s.

5. The control method according to any one of claims 1 to 4, wherein duration of the heat transfer sustaining stage ranges from 2 s to 3 s.

6. The control method according to claim 1, wherein before the providing power during the heat transfer sustaining stage to maintain a heat transfer rate between the heater and the aerosol forming substrate, the method comprises: detecting a real-time temperature of the heater; and when it is detected that the real-time temperature of the heater reaches a set maximum temperature threshold, entering the heat transfer sustaining stage.

7. The control method according to claim 1, wherein before the providing power during the heat transfer sustaining stage to maintain a heat transfer rate between the heater and the aerosol forming substrate, the method comprises: quantifying duration of the heat-up stage; and when the duration reaches a set threshold, entering the heat transfer sustaining stage.

8. A control method for an aerosol generating device, the aerosol generating device comprising a heater configured to heat an aerosol forming substrate to generate an aerosol and a power source providing energy to the heater, wherein the method comprises: entering a preheating operational stage after receiving a heating initiation instruction, wherein the preheating operational stage comprises a continuous output stage and an intermittent output stage; providing power during the continuous output stage to significantly raise a temperature of the heater; providing power during the intermittent output stage to maintain the temperature of the heater, wherein the power provided to the heater is decreased at least once within a time period of the continuous output stage.

9. The control method according to claim 8, wherein a supply amount of energy provided by the power source to the heater in the continuous output stage accounts for more than 80% of a supply sum of energy provided by the power source to the heater in the preheating operational stage.

10. The control method according to claim 8, wherein duration between the end of the continuous output stage and the end of the preheating operational stage ranges from 4 s to 10 s.

11. The control method according to claim 8, wherein during the intermittent output stage, the temperature of the heater fluctuates at a constant frequency; and / or during the intermittent output stage, the temperature of the heater fluctuates at a variable frequency.

12. The control method according to claim 8, wherein the intermittent output stage comprises a plurality of power output stages, and duration of each power output stage is greater than 500 ms.

13. The control method according to claim 8, wherein the providing power during the intermittent output stage to maintain the temperature of the heater further comprises: controlling the power source to initiate energy supply to the heater in a first power output stage; determining a supply amount of energy in the first power output stage; if the supply amount of energy supplied by the power source reaches set energy corresponding to the first power output stage, controlling the power source to stop the energy supply in the first power output stage; completing a natural cooldown period set for the first power output stage; and ending the first power output stage, and controlling the power source to initiate energy supply to the heater in a second power output stage.

14. The control method according to claim 13, wherein the completing a natural cooldown period set for the first power output stage comprises: detecting a real-time temperature of the heater within the natural cooldown period, and when it is detected that the real-time temperature of the heater reaches a set low temperature threshold, entering the second power output stage; or quantifying the natural cooldown period, and when the natural cooldown period meets a preset time threshold, entering the second power output stage.

15. An aerosol generating device, comprising: a heater, configured to heat an aerosol forming substrate to generate an aerosol; a power source, configured to provide energy to the heater; and a controller, configured to: in a preheating operational stage that sequentially comprises a heat-up stage, a heat transfer sustaining stage, and a heat retention stage, provide power during the heat-up stage to significantly raise a temperature of the heater; provide power during the heat transfer sustaining stage to maintain a heat transfer rate between the heater and the aerosol forming substrate; and provide power during the heat retention stage to maintain the temperature of the heater, wherein the power provided to the heater during the heat transfer sustaining stage is less than the power provided to the heater during the heat-up stage.

16. An aerosol generating device, comprising: a heater, configured to heat an aerosol forming substrate to generate an aerosol; a power source, configured to provide energy to the heater; and a controller, configured to: in a preheating operational stage comprising a continuous output stage and an intermittent output stage, provide power during the continuous output stage to significantly raise a temperature of the heater, and provide power during the intermittent output stage to maintain the temperature of the heater, wherein the power provided to the heater is decreased at least once during the continuous output stage.

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