An aerosol generating device

Abstract

There is provided an aerosol generating device (1) comprising: a consumable article (100) adapted to be inserted in the aerosol generating device by a user, the consumable article comprising a capacitor (160), the capacitor comprising an electrolyte which when heated generates an aerosol for inhalation by the user; a sensor (40) configured to detect pressure change in the aerosol generating device, and a control unit (10) configured to set a voltage for charging and / or discharging the capacitor to thereby control the heating of the electrolyte, wherein in response to the sensor detecting that the pressure change exceeds a first threshold, the control unit is configured to set the voltage at a first value, and in response to the sensor detecting that the pressure change exceeds a second threshold, the second threshold being higher than the first threshold, the control unit is configured to set the voltage at a second value.

Description

[0001] AN AEROSOL GENERATING DEVICE

[0002] TECHNICAL FIELD

[0003] The present invention relates to the field of aerosol generating device and in particular relates to an aerosol generating device adapted to receive a consumable article inserted in the aerosol generating device by a user .

[0004] BACKGROUND

[0005] In the recent years devices which heat rather than burn or cause combustion of a substance to generate a vapour or aerosol for inhalation by a user have become increasingly popular .

[0006] Such device which heat rather than burn or cause a combustion o f a substance may be tobacco-based device also known as heated tobacco products . These devices normally contain tobacco and / or other suitable substance that is heated but not burned to create an inhalable aerosol . The tobacco and / or the other suitable substance may in general also be called an aerosol generating substance and the device in general may be called an aerosol generating device .

[0007] Normally, the aerosol generating substance is placed in a container, also called a stick or a tobacco stick, that can be inserted in and removed from the aerosol generating device by the user . Therefore , the stick or the tobacco stick is also called a consumable article .

[0008] For heating the aerosol generating substance , the aerosol generating device uses a heating arrangement that may apply one or more di f ferent approaches to provide heat to the aerosol generating substance . The aerosol generating device normally comprises a battery for providing power to the heating arrangement . An aerosol generating device tends to resemble a conventional cigarette in many di f ferent aspects , for example , in the shape of the aerosol generating device and / or the shape of the consumable article and in one or more aspects of user experience when the user draws on the aerosol generating device .

[0009] In a conventional cigarette , the user is able to control the amount of vapour generated by controlling the strength of suction on the conventional cigarette .

[0010] This is an intuitive way that is natural for all smokers of conventional cigarettes .

[0011] There is a need for emulating this user experience associated to smoking of conventional cigarettes in an aerosol generating device .

[0012] SUMMARY

[0013] The mentioned problems and obj ects are met by the sub ect-matter of the independent claims . Advantageous embodiments are defined in the dependent claims .

[0014] According to an aspect of the present invention there is provided an aerosol generating device comprising : a consumable article adapted to be inserted in the aerosol generating device by a user, the consumable article comprising a capacitor, the capacitor comprising an electrolyte which when heated generates an aerosol for inhalation by the user ; a pressure change identi fication means for identi fying pressure change in the aerosol generating device , and a control unit configured to set a voltage for charging and / or discharging the capacitor to thereby control the heating of the electrolyte , wherein in response to the pressure change identi fication means identi fying that the pressure change exceeds a first threshold, the control unit is configured to set the voltage at a first value , and in response to the pressure change identi fication means identi fying that the pressure change exceeds a second threshold, the second threshold being higher than the first threshold, the control unit is configured to set the voltage at a second value .

[0015] BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Embodiments of the present invention which are presented for better understanding the inventive concept of the present invention, but which are not to be seen as limiting the present invention, will now be described with reference to the figures in which :

[0017] Figs . 1A and IB show a schematic view of the aerosol generating device according to the embodiment of the present invention;

[0018] Fig . 1C shows a schematic view of the consumable article to be used with the aerosol generating device according to the embodiment of the present invention;

[0019] Fig . 2A shows a schematic view of the consumable article to be used with the aerosol generating device according to the embodiment of the present invention;

[0020] Fig . 2B shows schematically the consumable article to be inserted in the aerosol generating device according to the embodiment of the present invention;

[0021] Figs . 3A, 3B and 3C show schematically a part of the consumable article to be used with the aerosol generating device according to the embodiment of the present invention;

[0022] Fig . 4 shows schematically the functional units of the aerosol generating device of the embodiment of the present invention; Fig . 5 shows schematically the functional blocks of the control unit of the aerosol generating device according to the embodiment of the present invention;

[0023] Fig . 6 shows schematically the temperature profile during a vaping session;

[0024] Fig . 7 shows schematically another temperature profile during a vaping session;

[0025] Fig . 8 shows schematically the internal resistance of the consumable article during a vaping session;

[0026] Fig . 9 shows schematically the temperature profile and control of the voltage during a vaping session;

[0027] Figs . 10A and 10B shows examples of look-up tables stored in the memory of the aerosol generating device according to an embodiment of the present invention;

[0028] Fig . 11 show schematically a relation between the current and the voltage during operation of the aerosol generating device according to an embodiment of the present invention;

[0029] Fig . 12 shows schematically a relation between the current and the temperature during operation of the aerosol generating device according to an embodiment of the present invention;

[0030] Fig . 13 shows schematically the control unit of the aerosol generating device according to an embodiment of the present invention; DETAILED DESCRIPTION

[0031] Figure 1A shows a schematic view of the aerosol generating device 1 according to the embodiment of the present invention .

[0032] The aerosol generating device 1 is a handheld device that may have a pebble-like shape and normal ly comprises an access portion 4 and a housing portion 2 . The access portion 4 is in the top part of the aerosol generating device 1 and may comprise means for opening and closing an opening 3 to a cavity of the aerosol generating device 1 . In the cavity, a user may place at least one consumable article 100 comprising an aerosol generating substance . The access portion 4 may comprise for example a lid that can at least partly be removed from the housing portion 2 ( for example along the direction shown with the double pointing arrow in figure 1A) . In other embodiment shown in figure IB the access portion 4 may comprise for example a slider . The slider may be moved between two positions ( along the direction shown with the double pointing arrow in figure IB ) such as opened position and closed position for opening and closing the opening 3 to the cavity .

[0033] The aerosol generating device 1 may comprise on the outer side of the housing portion 2 one or more input means (not shown in the figure ) . The input means may comprise , for example , one or more buttons for controlling, for example turning on or of f the aerosol generating device 1 . The aerosol generating device 1 may comprise on the outer side of the housing portion one or more output means (not shown in the figure ) . The one or more output means may comprise one or more light emitting devices or a display for conveying an information to the user . The information may be related to operation of the aerosol generating device 1 and / or related to the consumable article 100 .

[0034] The housing portion 2 of the aerosol generating device 1 may have a smooth outer surface which together with the pebble-like shape provides a physical ergonomic advantage for the user . The housing portion 2 houses at least the mentioned cavity and houses further components of the aerosol generating device 1 as elaborated below .

[0035] In other embodiment of the present invention, the aerosol generating device 1 may have a cylindrical form . A cylindrical form resembles more closely the shape of a conventional cigarette .

[0036] The user can place a consumable article 100 containing an aerosol generating substance into the cavity of the aerosol generating device 1 via the opening 3 .

[0037] Figure 1C shows a schematic view of the consumable article 100 according to the embodiment of the present invention to be inserted in the aerosol generative device 1 according to the embodiment of the present invention . The consumable article 100 may be a stick or a tobacco stick comprising tobacco and / or other suitable substance that is heated but not burned in the cavity to create an inhalable aerosol . The consumable article 100 may further comprise a flavour adding substance . The consumable article 100 may have an elongated form, for example a cylindrical form as shown in figure 1C . The consumable article 100 may be partitioned in two parts : in the first part 110 the aerosol generating substance is placed while the second part 120 is the part on which the user draws on the consumable article 100 . The second part 120 may be a mouthpiece or a filter portion or a combination of both .

[0038] The cavity of the aerosol generating device 1 mentioned above may be such that the user can place one consumable article 100 in the aerosol generating device 1 or the user may place more than one consumable article 100 in the aerosol generating device . The cavity may also have a cylindrical form as the consumable article 100 . The form of the consumable article 100 and the form of the cavity are not to be seen as limiting to the concept o f the present invention . There is shown in figure 2A a consumable article 100 according to the embodiment of the present invention .

[0039] The consumable article 100 according to the embodiment of the present invention comprises a capacitor 160 . The capacitor 160 comprises an electrolyte which when heated generates an aerosol for inhalation by the user .

[0040] The capacitor 160 may be surrounded by a layer 110 . The layer 110 may be a paper wrap . The paper wrap may be coated with metal or polymer coating to thereby form the outer casing of the consumable article 100 . Alternatively, the capacitor 160 surrounded by the layer 110 may be inserted in an outer casing of the consumable article 100 .

[0041] The capacitor 160 may be an electrochemical double-layer capacitor . The capacitor 160 may have a spiral wound ( j elly roll ) construction . The capacitor 160 may have a cylindrical construction, as shown in figure 3A that shows the ( circular ) cross-section of the capacitor 160 . However, a capacitor 160 having the same spiral wound may be flattened so that it has more cuboid shape , as shown in figure 3B that shows the ( rectangular ) cross-section of the capacitor . Such shape may be more preferable for a flat- formed consumable article 100 .

[0042] There is shown in figure 3C the structure of the capacitor 160 . The capacitor 160 normally includes a positive electrode 260 and a negative electrode 360 . The electrodes 260 , 360 are separated by a pair of porous separators 460a, 460b . The positive electrode 260 includes a positive current collector 262 . The material of the positive current collector 262 may be an aluminium, for example in a form of an aluminium foil . Each side of the positive current collector 262 is provided with a porous carbon-based electrode layer 261 such as a layer of porous charcoal material or activated carbon, for example .

[0043] The negative electrode 360 includes a negative current collector 362 . Each side of the negative current collector 362 is provided with a porous carbon-based electrode layer 361 such as a layer of porous charcoal material or activated carbon, for example . The material of the positive current collector 362 may be an aluminium, for example in a form of an aluminium foil .

[0044] The separators 460a, 460b may be formed from a tobacco material such as a porous tobacco sheet which releases volatile compounds when it is heated . The separators may also be formed from other material , for example plant-based material .

[0045] The electrodes 260 , 360 and the separators 460a, 460b are immersed in an electrolyte which permits cation and anion migration when the capacitor 160 is charged or discharged, and generates an aerosol for inhalation by the user when it is heated . The electrolyte may comprise sodium chloride and glycerol , and optionally polyvinyl alcohol as a gelling agent . The electrolyte is soaked into the separators 460a, 460b, for example the porous tobacco sheet .

[0046] Additionally, or alternatively other food-grade electrolytes may also be used . The thickness of the separators defines the final and total electrical resistance of the consumable article 100 .

[0047] There is shown in figure 2A that the consumable article 100 includes a positive capacitor terminal 150 . The positive capacitor terminal 150 is electrically connected to the positive electrode 260 , i . e . , to the positive current collector 262 at one or more locations . The consumable article 100 includes further a negative capacitor terminal 140 . The negative capacitor terminal 140 is electrically connected to the negative electrode 360 , i . e . , to the negative current collector 362 , at one or more locations . The capacitor terminals 140 , 150 may be located inside the outer casing of the consumable article 100 or inside the layer 110 so that they are not accessible to the user .

[0048] There is shown in figure 2A that the consumable article 100 may comprise a member 130 being arranged above (when viewed as shown in the figure 2A) the positive capacitor terminal 150 and being a layer of insulating material to avoid short-circuiting outside of the aerosol generating device 1 when the consumable article 100 is inserted in the aerosol generating device 1 . This may be particularly relevant for cases when the housing portion 2 of the aerosol generating device 1 is made of a conducting material , for example aluminium .

[0049] Figure 2B shows the aerosol generating device 1 adapted to receive the consumable article 100 in the above-mentioned cavity . As elaborated above , the consumable article 100 is inserted in the cavity of the aerosol generating device 1 via the opening 3 .

[0050] The aerosol generating device 1 may include a pair of means (not shown in the figure ) , for example rupturing means that are adapted to rupture the consumable article 100 when it is inserted into the cavity and has taken the intended location in the cavity such that each of the rapturing device makes an electrical connection with the respective one of the positive capacitor terminal 150 and the negative capacitor terminal 140 . Via the respective lines 141 , 151 an electrical connection is established between the capacitor terminals 140 , 150 via a switching unit 20 to a power source 30 ( for example a battery) of the aerosol generating device 1 . The rupturing means are not limiting to the aerosol generating device and other ways of ensuring a reliable electrical connection between the capacitor terminals 140 , 150 and the power source 30 via the switching unit 20 may be applied .

[0051] Figure 4 shows schematically functional units of the aerosol generating device 1 . It is to be understood that the shown functional units are not limiting to the aerosol generating device 1 . There is shown in figure 4 that the aerosol generating device 1 may comprise a control unit 10 , a switching unit 20 , a power source 30 , a sensor unit 40 and a memory 50 . The control unit 10 is any suitable unit or comprises any suitable unit such as computer processing unit that can perform computer processing . The control unit 10 ( also called controller ) may be for example a microprocessor unit (MCU) or a microcontroller unit (MCU) . The control unit 10 is configured to set a voltage for charging and / or discharging the capacitor 160 to thereby control the heating of the electrolyte . Details are elaborated further below .

[0052] The switching unit 20 may include the above-mentioned rupturing device which function as positive and negative terminals and are electrically connected to the positive and negative capacitor terminals 140 , 150 when the consumable article 100 is properly received in the cavity of the aerosol generating device 1 . The switching unit 20 may comprise one or more switches for example . The switches may be semiconductor switching devices , e . g . , field ef fect transistors . The switching unit 20 may be functionally or logically divided into a switching unit for controlling the discharging of the capacitor 160 and a switching unit for controlling the charging of the capacitor 160 . However, this is not limiting, and the skilled person can provide the switching unit 20 appropriate for operating the consumable article 100 by carrying out discharging and charging of the capacitor 160 .

[0053] The power source 30 may be a battery or other energy storage device . The battery may be a rechargeable battery .

[0054] The sensor unit 40 may comprise one or more sensors or means , for example a sensor for measuring pressure change in the aerosol generating device 1 , a temperature sensor for measuring the temperature on the positive capacitor terminal 150 , a current sensor and similar . Other sensors may also be provided . Di f ferent sensors of the sensor unit 40 and their function in the aerosol generating device according to the embodiment of the present invention will be described further below .

[0055] The memory 50 may store di f ferent information needed for the processing by the control unit 10 . Further, the memory may store computer program ( code ) comprising instructions which, when the program is executed by the control unit 10 , cause the control unit 10 to carry out the process ing of the embodiment of the present invention as will be elaborated further below .

[0056] In one or more embodiments of the present invention, the aerosol generating device 1 may comprise a heater (not shown in the figure ) . Such heater in respect to the consumable article 100 may be called external heater . The heater may be a thin film metal to provide resistance heating . However, a heater is entirely optional .

[0057] In the consumable article 100 , the capacitor 160 is normally pre-charged during the manufacturing process and is packaged and sold to the user in a pre-charged state .

[0058] After the consumable article 100 has been properly inserted into the cavity of the aerosol generating device 1 ( as elaborated above , an electrical connection has been established between the capacitor terminals 140 , 150 and the power source 30 via the switching unit 20 ) and the aerosol generating device 1 has been activated by the user ( for example by way of the user pressing a button on the input means described above , or by way of the user drawing on the consumable article 100 ) , the capacitor 160 may be discharged by controlling the switching unit 20 by the control unit 10 to provide a continuous or switched short circuit path between the positive and negative capacitor terminals 140 , 150 of the capacitor 160 of the consumable article 100 , and hence between the positive and negative electrodes 260 , 360 of the capacitor 160 . The short circuit path between the positive and negative terminals 140 , 150 is formed via the switching unit 20 .

[0059] Additionally, the switching unit 20 may comprise a resistor to prevent over-discharge current or an electrical load to enable constant current discharge .

[0060] Discharging the capacitor 160 through the switching unit 20 dissipates heat in the electrodes 260 , 360 . This heats the electrolyte of the capacitor 160 and generates an aerosol that may be inhaled by the user through the second part 120 of the consumable article 100 . It is to be understood that in the consumable article 100 a path may be provided for delivering the generated aerosol in the capacitor 160 to the second part 120 of the consumable article 100 .

[0061] The above-mentioned temperature sensor of the sensor unit 40 may measure the temperature on the positive capacitor terminal 150 since the aluminium foil normally used as a positive current collector 262 is a good thermal conductor . Based on the measured temperature , the short-circuiting via the switching unit 20 can be controlled according to pulsed width modulation ( PWM) scheme and constant power for charging and discharging can be achieved for avoiding overheating . Normally, the cycling between charging and discharging of the capacitor 160 ( the cycling being described here below) is interrupted when the temperature exceeds a particular predetermined temperature .

[0062] Pre-charging the capacitor 160 reduces the amount of energy that is required from the power source 30 of the aerosol generating device 1 for heating . This may lead to a reduction in the overall si ze and weight of the aerosol generating device 1 . In particular, the si ze and weight o f the power source 30 may be reduced . This is signi ficant because the power source is often the largest and heaviest component of the device 30 .

[0063] After the capacitor 160 gets discharged, it may be ( re ) charged

[0064] The capacitor 160 may be charged from the power source 30 by controlling the switching unit 20 by the control unit 10 . Charging the capacitor 160 also dis sipates heat in the electrodes 260 , 360 , which heats the electrolyte in the capacitor 160 and generates an aerosol that may be inhaled by the user .

[0065] Heat for heating the electrolyte may therefore be generated by repeatedly discharging the capacitor 160 and subsequently charging the capacitor 160 from the power source 30 , and hence by cycling between discharging and charging of the capacitor 160 .

[0066] The cycling between discharging and charging of the capacitor 160 may continue until the vaping session ends . The vaping session may end by way of the user ending the vaping session, for example by way of pressing a button on the above-described input means to thereby turn-of f the aerosol generating device 1 or by way of the electrolyte being fully vapori zed or by way of the user not drawing on the consumable article 100 for a predetermined amount of time . When the electrolyte is fully vapori zed, the current will not flow since the electrical contact between the capacitor terminals 140 , 150 is lost , and hence the vaping session ends . The vaping session may also end i f a particular number of draws by the user on the consumable article 100 is reached .

[0067] Figure 5 shows schematically the functional blocks of the control unit 10 of the aerosol generating device .

[0068] Referring to figure 5 , the switching unit 20 is controlled by the controller 12 of the control unit 10 . The controller may include a closed loop controller . The closed-loop controller 12 may be a RID controller (proportional-integral-derivative controller ) . Temperature measurements T of the temperature of the positive capacitor terminal 150 by the temperature sensor of the sensor unit 40 are provided to a temperature estimation block 13 . The temperature estimation block 13 may also receive values of an electrical parameter EL of the capacitor 160 such as internal resistance or capacitance , which may be estimated or determined using current and voltage measurements . The temperature estimation block 13 may output an estimated internal temperature EST of the capacitor 160 to a comparator block 11 . The temperature estimator block 13 may estimate the internal temperature EST based on the temperature measurements T and / or the values of the electrical parameter EL of the capacitor 160 ( for example the internal resistance ) . The error E between the estimated internal temperature of the capacitor EST and a temperature profile TP is calculated by the comparator unit 11 and is provided to the closed loop controller 12 which controls the switching unit 20 . The temperature profile TP may be a pre-defined temperature profile .

[0069] The closed loop controller 12 may be a PID controller, as mentioned above , with a proportional constant Kp, an integral constant Ki and a derivative constant Kd . The controller constants may be varied by an auto-tuning block 14 based on the values of the electrical parameter EL of the capacitor 160 ( for example the internal resistance ) provided by the temperature estimation block 13 to the auto-tuning block 14 , and the temperature measurements T of the temperature of the positive capacitor terminal by the temperature sensor provided also by the temperature estimation block 13 to the auto-tuning block 14 .

[0070] Varying the controller constants allows the discharging and / or charging of the capacitor 160 to be adj usted i f the electrical parameter EL ( for example the internal resistance ) of the capacitor 160 changes during a vaping session as a result of heating and / or the reduction in the amount of electrolyte as it is inhaled as an aerosol by the user . This allows the control unit 10 to provide robust and accurate heating control over the whole of the vaping session .

[0071] The auto-tuning block 14 may use a neural network or any other sort of adaptive control or learning process , or a model-based process , for example for varying the controller constants Kp, Ki , Kd . The auto-tuning block 14 may also use a look-up table that relates the electrical parameter EL or temperature T to a particular controller constant , for example . By way of example , the auto-tuning block 14 may use pre-programmed sets of parameters for each internal resistance of the capacitor 160 . In a di f ferent example , the auto-tuning could be based on a plant model , which is continuously updated . For this , a plant unit 15 may be provided . The plant model involves plant identi fication and model-based control . Other known tuning models may also be used .

[0072] The auto-tuning block 14 provides the updated controller constants (Kp, Ki , Kd) to the closed-loop controller 12 that determines the constant power for charging and discharging of the capacitor 160 and sets the voltage for charging and discharging of the capacitor based on the determined constant power for charging and discharging to thereby control the heating of the electrolyte . Setting the voltage may involve setting the maximum voltage for charging and discharging of the capacitor 160 .

[0073] Figure 6 is representative example of a vaping session that includes a pre-heating phase PHP and a heating or vaping phase VP and shows the development of the temperature of the electrolyte with time . It is to be understood that the preheating phase PHP, as described here below, is not mandatory . It is to be understood that pre-heating may also be performed by way of using the external heater mentioned above .

[0074] Before the start of the pre-heating phase PHP, for example , when the consumable article 100 is inserted into the device 1 , an identi fication step ( indicated by " ( 0 ) " ) may be carried out to determine an operating parameter and status of the capacitor 160 and check the authenticity of the consumable article 100 . During the identi fication step, the pre-charged capacitor 160 is discharged a plurality of times ( e . g . , five times ) . Each discharge is only for a very short period of time ( e . g . , about 10- 100 ms ) . An average value of an electrical parameter EL of the capacitor 160 such as internal resistance , capacitance , discharging rate , SOC, or SOH of the capacitor is determined using at least one of current , voltage and time measurements taken during each discharge . The average value of the electrical parameter EL may be used to detect i f the consumable article 100 is damaged or faulty . The average value of the electrical parameter of the capacitor 160 may also be used to adj ust operating characteristics of the aerosol generating device 1 . Authenticity of the consumable article 100 may be established i f , for example , the average value of the electrical parameter EL is within a predefined range or is above or below a predefined threshold . I f the consumable article 100 is not authentic, further operation of the aerosol generating device 1 may be stopped . It is to be understood that the identi fication step is optional .

[0075] During the vaping session VP, the heating of the electrolyte is controlled by controlling the discharging and charging of the capacitor 160 based on an estimated or determined temperature of the capacitor 160 and the above-mentioned temperature profile TP . The discharging and charging of the capacitor 160 are controlled based on comparison between the estimated temperature EST and a target temperature of the temperature profile TP, as elaborated above with respect to figure 5 .

[0076] The discharging and charging power may be adj usted after every temperature estimation .

[0077] During the pre-heating phase PHP, the capacitor 160 is repeatedly cycled between discharging and charging to continuously heat the capacitor ( indicated by " ( 1 ) " ) • The capacitor 160 is discharged and charged at a particular discharging and charging power that can provide rapid heating of the capacitor 160 towards a target temperature .

[0078] During the vaping phase VP, the discharging and charging of the capacitor 160 is controlled to vary the temperature of the capacitor 160 according to the temperature profile TP to provide desired heating of the electrolyte . For example , i f the capacitor 160 is to be maintained at a particular temperature to provide substantially constant heating of the electrolyte , the capacitor 160 may be discharged and charged at a particular discharging and charging power ( indicated by " ( 2 ) " ) , where the discharging and charging power may be seen to be lower than the discharging and charging power during the pre-heating phase PHP where more rapid heating is needed . I f the capacitor temperature needs to decrease, the switching unit 20 may be disabled so that the capacitor 160 is neither discharged nor charged and no heating is provided (indicated by " (3)") . If the capacitor 160 temperature needs to increase to provide additional heating of the electrolyte, the capacitor 160 may be discharged and charged at a particular discharging and charging power (indicated by " (1)") , where the discharging and charging power may be seen to be higher than the discharging and charging power for maintaining the capacitor's 160 temperature (indicated by " (2)") and then the temperature may be maintained by applying the charging and discharging power as indicated with " (2)".

[0079] Figure 6 therefore shows how the heating of the electrolyte may be varied by controlling the discharging and charging power of the capacitor 160 in order to control the amount of heat that is dissipated in the electrodes of the capacitor 160.

[0080] The capacitor 160 is discharged and charged between pre-defined upper and lower limits. This is shown in the right panel of figure 6. In figure 6 the upper and lower limits are expressed in terms of state of charge (SOC) and the upper limit is about 50-80% and the lower limit is about 20-40%. SOC is here defined as the available capacity (in Ah) of the capacitor 160 and is expressed as a percentage of its rated capacity. It will be understood that other pre-defined upper and lower limits may be selected and that they may be expressed in different terms such as voltage, for example. Since an output voltage V of the capacitor 160 corresponds to the SOC of the capacitor, the output voltage V of the capacitor 160 may be used instead of SOC. In particular, the state of charge SOC with respect to time is shown in figure 6 for each of the periods indicated as (1) , (2) and (3) above. As evident, for the state labelled with " (1)" more rapid cycling between discharging and charging is carried out than for the state labelled as " (2)". For the state labelled as " (3)" there is neither charging nor discharging.

[0081] As elaborated above, in the consumable article 100, the capacitor 160 is normally pre-charged during the manufacturing process and is packaged and sold to the user in a pre-charged state . In the time period from pre-charging the capacitor during the manufacturing process to the user actually inserting the consumable article 100 in the aerosol generating device for usage , the capacitor 160 may discharge ( due to sel f-discharge ) either entirely or down to a particular voltage or SOC . Therefore , in the control algorithm for discharging and charging, the control algorithm starting with discharging in each of the pre-heating phase PHP and the vaping phase VP, the pre-defined lower limit will either be reached already due to this possible ( sel f- ) discharging of the capacitor 160 or will be reached very fast in the first discharging and the control algorithm will switch to charging in the repeated cycling between discharging and charging of the capacitor 160 .

[0082] The control algorithm starting with discharging in each of the pre-heating phase PHP and the vaping phase VP increases the robustness of the control algorithm to the capacitor 160 being possibly discharged fully or discharged to a particular voltage or SOC when the consumable article 100 is inserted in the aerosol generating device 1 for usage .

[0083] It is to be understood that regarding the repeated cycling, in the present disclosure ( repeated) cycling between discharging and charging and ( repeated) cycling between charging and discharging are interchangeably used .

[0084] Figure 7 is representative of an alternative vaping session that includes a pre-heating phase PHP and a heating or vaping phase VP and shows the development of the temperature of the electrolyte with time .

[0085] Before the start of the pre-heating phase PHP, for example , when the consumable article 1 is inserted into the device 100 , an identi fication step ( indicated with arrow and " ( 0 ) " ) may be carried out to determine an operating parameter and status of the capacitor 160 , and check the authenticity of the consumable article 100 , as elaborated above . At the start of the pre-heating phase PHP, the capacitor 160 is repeatedly cycled between discharging and charging until a threshold temperature Tth is reached . Once the threshold temperature Tth is reached ( shown with the circle ) , the capacitor 160 is not discharged or charged and the capacitor 160 is heated by the external heater mentioned above . The threshold temperature Tth may be about 180-230 ° C, for example . The heating provided by the one or more external heaters , mentioned above , may heat the capacitor 160 to a target temperature of about 280 ° C .

[0086] When the capacitor 160 is being heated by the external heater, temperature estimation steps are carried out . In each temperature estimation step, the capacitor 160 is charged and discharged a plurality of time ( e . g . , three times ) shown with the State of Charge / Voltage vs time graph . An average value of an electrical parameter EL of the capacitor 160 is determined using at least one of current and voltage taken each time the capacitor 160 is discharged and / or charged . The average value of the electrical parameter EL is then used to estimate the temperature of the capacitor 160 . The electrical parameter may be the internal resistance or capacitance of the capacitor 6 , as elaborated above , for example , which is directly proportional to the temperature of the capacitor 160 .

[0087] In some embodiments of the present invention, the heating of the electrolyte of the capacitor 160 during the vaping session VP may also be a combination of cycling between discharging and charging as shown with reference to figure 6 and heating by the external heater, as shown with reference to figure 7 .

[0088] There is shown in figure 8 the internal resistance of the capacitor 160 , as an example of the electrical parameter EL with time . The internal resistance may be measured directly at the beginning of each discharge part of the charging / discharging cycle (<100 ms part of the cycle ) . During the time period denoted with the rectangle I the temperature of the capacitor 160 increases and the internal resistance drops . The circle denotes the time point from where closed loop control , for example by way of using the closed-loop controller as elaborated above with reference to figure 5 is needed . During the time period denoted with the rectangle I I signi ficant vapori zation occurs , the internal resistance increases due to reduction of the active surface area ( due to progress of the electrolysis ) .

[0089] During the vaping session VP, the user normally performs draws that are very similar in the drawing strength . Such draws reflect the " standard" drawing behaviour of the user . However, occasionally, during the vaping session, the user may draw stronger on the consumable article 100 and may want , as in conventional cigarette , that during such strong draw to have a higher amount of aerosol available for inhalation . This may increase the taste satis faction of the user as well as the versatility of the aerosol generating device 1 .

[0090] The embodiment of the aerosol generating device 1 of the present invention enables that a higher amount of aerosol is generated when the user draws stronger on the consumable article 100 ( as it is the case for conventional cigarettes ) . It is to be noted that the words "vapour" and "aerosol" are interchangeably used .

[0091] This concept is elaborated based on figure 9 which shows the temperature profile during the vaping session, VP, shown in figure 6 . By way of example , the user may want to have a larger amount of aerosol during a draw that is undertaken in the time period indicated with the dashed circle . This time period falls within the time period denoted as "2" in figure 6 during which the control unit 10 is configured to control repeated discharging and charging of the capacitor 160 to thereby control the heating of the electrolyte for maintaining the temperature of the electrolyte .

[0092] In the embodiment of the present invention, the aerosol generating device 1 comprises a pressure change identi fication means for identi fying pressure change in the aerosol generating device 1 . The pressure change identi fication means may be or may comprise a sensor . For example , the pressure change identi fication means may be or may comprise the sensor for measuring pressure change in the aerosol generating device 1 of the sensing unit 40 described above . The pressure change identi fication means may be or may comprise more than one sensor . It is to be understood that the pressure change may be defined with respect to a reference value . An example of a reference value may be the pressure in the aerosol generating device when the user is not drawing on the consumable article 100 ( this pressure may also be called ambient pressure ) .

[0093] In general , the pressure change identi fication means may perform direct identi fication of pressure change , via, for example , a direct measurement or direct sensing of the pressure change , or indirect , via, for example , one or more parameters directly or indirectly related to the pressure change . The pressure change identi fication means identi fying pressure change may also be understood as the pressure change identi fication means determining or detecting pressure change in the aerosol generating device 1 . Further, the pressure change identi fication means may comprise one or more sensors as described above and one or more processing units for evaluating the data regarding pressure change collected by the one or more sensors . Alternatively, or additionally, the control unit 10 may evaluate the data regarding pressure change collected by the one or more sensors . For example , the one or more sensors may measure the pressure in the aerosol generating device 1 and the one or more processing units or the control unit 10 may determine the pressure change based on the measured values for the pressure .

[0094] By way of an example , in an embodiment of the present invention, the pressure change identi fication means may be the sensor for measuring pressure change in the aerosol generating device 1 of the sensing unit 40 described above . This sensor may be a flow sensor, a thermocouple or pressure sensor arranged to measure the pressure in the aerosol generating device 1 . For example , the sensor may detect the air stream passing through the aerosol generating device 1 for identi fying ( or detecting) pressure change in the aerosol generating device . The sensor may perform measurements at a particular time interval , for example each 100 ms . The sensor may send the measured pressure values to the control unit 10 or other processing unit . The control unit 10 or other processing unit may be configured to evaluate and hence to identi fy or determine the pressure change based on the received measured values by the sensor . At least two thresholds may be set for the pressure change : a first threshold and a second threshold . Each of the first threshold and the second threshold may be pre-defined .

[0095] For each of these thresholds , the aerosol generating device 1 can operate the capacitor 160 o f the consumable article 100 di f ferently, that is , the aerosol generating device 1 can operate the capacitor 160 of the consumable article 100 in a " standard" mode of operation ( first mode of operation) or in a mode for generation of extra aerosol ( second mode of operation) .

[0096] The first threshold may be seen as a threshold for operation of the consumable article 100 in the " standard" mode . The first threshold may be set at a low value in order to account for di f ferent smoking behaviours of di f ferent users . This may require in turn setting a larger di f ference between the first threshold and the second threshold for detecting stronger puf fs ( draws ) . In some embodiments , the first threshold may be set during the manufacturing of the aerosol generating device 1 , by way of studying the drawing (puf fing) behaviour of a particular number of users . In some embodiments , the user of the aerosol generating device 1 may set the first threshold, after the user has acquired the aerosol generating device 1 , for example during a learning phase in which the user may train the acquired aerosol generating device 1 . Training of the aerosol generating device 1 may be seen as introducing settings in the aerosol generating device 1 based on the user' s preferences . For example , the user may draw several times on the aerosol generating device 1 in a way to correspond to the " standard" way for drawing by the user , and the first thresholds may be set based on the pressure change resulting from these draws .

[0097] It is to be understood that the present invention is not limited to a speci fic way of identi fying a pressure change nor to the speci fic unit ( for example the speci fic structural element ) that carries out identi fication ( or determination) of the pressure change . The skilled person understands that the pressure change is an information which may be obtained with suitable means for identi fying the pressure change in the aerosol generating device 1 , based on which information the aerosol generating device 1 can operate the capacitor 160 of the consumable article 100 in the " standard" mode of operation ( first mode of operation) or in the mode for generation of extra aerosol ( second mode of operation) as elaborated here .

[0098] Figure 6 above may be seen as showing a vaping session during the " standard" mode . In figure 9 the described " standard" mode may extend until time tl . By way of example , the time tl is a time point in the time period in which the discharging and charging power indicated with " ( 2 ) " in figure 6 for maintaining the temperature is applied . The control by the control unit 10 may be performed as elaborated above with respect to figure 5 .

[0099] In response to the pressure change identi fication means identi fying that the pressure change exceeds the first threshold, the control unit 10 is configured to set the voltage at a first value (Vx in figure 9 ) . The control unit 10 is configured, to control based on the voltage set at the first value , repeated discharging and charging of the capacitor 160 to thereby control the heating of the electrolyte , for maintaining the temperature of the electrolyte .

[0100] The second threshold may be seen as a threshold for generating extra aerosol from the capacitor of the consumable article 100 or in other words for operating the capacitor of the consumable article 100 in the mode for generation of extra aerosol ( second mode of operation) . In response to the pressure change identi fication means identi fying that the pressure change exceeds the second threshold ( at time point tl ) , the second threshold being higher than the first threshold, the control unit 10 is configured to set the voltage at a second value V2.

[0101] The second value V2is higher than the first value V2.

[0102] In one embodiment of the present invention, based on the voltage set at the second value V2, the control unit 10 is configured to control repeated charging and discharging of the capacitor 160 to thereby control the heating of the electrolyte .

[0103] In other embodiment of the present invention, based on the voltage set at the second value V2, the control unit is configured to control charging of the capacitor 160 in a constant voltage mode .

[0104] This control based on the voltage set at the second value V2may be carried out for a pre-determined period of time ( in figure 9 until a time point t2 ) , for example for 2 s . The period of time may also be pre-set to reflect the duration of a stronger draw by the user .

[0105] The voltage during the operation in the mode for extra aerosol generation is shown in the dashed line rectangle A in figure 9 . In other words , there is shown in the dashed line rectangle A cycling between charging and discharging with the voltage set at the second value V2which is higher than the first voltage value Vi .

[0106] The dashed line rectangles B shows the voltage during the " standard" mode of operation during which cycling of charging and discharging of the capacitor 160 for maintaining the heating profile is carried out based on the voltage set at the first value Vi . As indicated above , the setting of the voltage at the second value V2in the time period denoted with the dashed line rectangle A may also be carried out as constant charging of the capacitor 160 . This is shown in the figure with the straight dashed line C .

[0107] Cycling between charging and discharging of the capacitor 160 with higher voltage ( that is based on the voltage set at the second value V2) corresponds to charging and discharging with higher charging and discharging power compared to the cycling between charging and discharging in the " standard" mode of operation . This promotes faster vapori zation of the electrolyte since the higher voltage enhances the electrolyses , which increases the amount of heat generated, which in turn enables that a larger amount of electrolyte is vapori zed .

[0108] In this case , the current that is provided from the power source 30 is a sum of the current required for charging the capacitor 160 and the current for electrolysis of the electrolyte . The current for electrolysis of the electrolyte is the current that is consumed for the extra vapour generation .

[0109] In one or more embodiments of the present invention, the control unit 10 may be configured to determine the second value of the voltage based on the identi fied pressure change amount by the pressure change identi fication means and one or more associations of one or more parameters .

[0110] For this , the one or more associations of one or more parameters may be stored in the memory 50 , mentioned above .

[0111] In one or more embodiments of the present invention, the one or more associations of one or more parameters may pre-defined and may be stored in the memory 50 as at least one look-up table . It is to be understood that a look-up table is not mandatory and the one or more associations of one or more parameters may be stored in the memory 50 as mathematical relations ( functions ) . Figure 10A shows schematically a general look up table that may be employed in embodiments of the present invention. In the lookup table, each parameter (P_l, P_2...P_n) may have several values (v_l, v_n) assigned. Figure 10B shows a plurality of look up tables, each look up table corresponding to one parameter P_l, P_2,...P_n. The value v_l of one parameter P_1 may be associated with the value v_2 of another parameter P_2 and so on.

[0112] In one or more embodiments of the present invention, one parameter is an amount of aerosol. The amount of aerosol may be defined as the difference amount of aerosol between the amount of aerosol generated when the voltage is set at the first value to the amount of aerosol generated when the voltage is set at the second value.

[0113] In one or more embodiments, the difference amount of aerosol may be the difference amount of aerosol in a predetermined time period, for example Is, or 2s, or 3 s . The time period may be determined based on the duration of a stronger draw by the user. This may be done already at the manufacturing stage of the device, or the user may configure the aerosol generating device 1 during the learning phase when the user trains the aerosol generating device 1.

[0114] The one or more associations of the one or more parameters may be based on several relations described here below.

[0115] The first relation is establishing an association between the difference amount of aerosol and the pressure change amount. In other words, the difference amount of aerosol is a function of the pressure change amount.

[0116] For this, the memory, for example in the look-up table, may store a plurality of difference amounts of aerosol and a plurality of pressure change amounts. In the memory, for example in the lookup table, each of the plurality of difference amounts of aerosol is stored in association with one of the plurality of pressure change amounts. The association between each of the plurality of difference amounts of aerosol with the corresponding one of the plurality of pressure change amounts may be based on pre-defined user preferences. By way of example, when the user acquires the aerosol generating device 1, the user may train the aerosol generating device 1 by way of drawing with different strength on the aerosol generating device 1 during the learning phase. For each draw for which the pressure change exceeds the second threshold, the user may set a value (using for example the above- mentioned input means) regarding a desired difference amount of aerosol. In the memory 50, the information regarding the pressure change may be stored and the corresponding association with a corresponding difference amount of aerosol may be set and stored.

[0117] For example, for a draw that effects a pressure change of approximately 25% above the first threshold a difference amount of aerosol (also called extra amount of aerosol) of Img may be set. For a draw that effects a pressure change of approximately 50% above the first threshold, a difference amount of aerosol of 2mg may be set.

[0118] Another relation establishes a relation between the difference amount of aerosol and a target current value for charging and / or discharging the capacitor 160. In other words, the target current value is a function of the difference amount of aerosol in mg. This is a proportional relation based on electrolysis law. This relation depends strongly on the amount of salt in the electrolyte. For this, the target current value may be considered as a parameter and the memory may store, for the example in the mentioned look-up table, a plurality of target current values, wherein in memory, for example in the look-up table, each of the difference amounts of aerosol is stored in association with one of the target current values.

[0119] A further relation establishes an association between the target voltage (that is the second voltage value) , the current target value and the temperature of the electrolyte. The target voltage may be seen as the maximum voltage for discharging and charging the capacitor 160 . For this , the memory, for example in the lookup table , may store a plurality of second voltage values , wherein each of the plurality of second voltage values is stored in association with one of the target current values .

[0120] Further, the memory, for example in the look-up table , may store a plurality of temperatures of the electrolyte . In the memory, for example in the look-up table , each of the plurality of target current values may be stored in an association with one of the temperatures of the electrolyte .

[0121] Based on these associations , the control unit 10 may be configured to select or determine the second value , for example from the look-up table , based on the identi fied pressure change amount by the pressure change amount identi fication means , the temperature of the electrolyte and the target current value associated to the temperature of the electrolyte .

[0122] For the association between the current target value and the temperature of the electrolyte , few relations are needed to be saved in the memory . This is relevant , since , to maintain the dimensions of the aerosol generating device 1 within limits that enable the aerosol generating device 1 to be held in the hand of the user, it is required that the si ze of the components and that is also the si ze of the memory 50 is small . The number of saved relations depends on the number of temperature steps . The temperature steps may also be called temperature profiles . The higher the temperature , the lower voltage is needed to generate the same amount of aerosol .

[0123] There is shown in figure 11 the relation between the target current and the voltage for two di f ferent electrolytes with di f ferent amount of salt . The circles represent an electrolyte with 1 % of salt and the rectangles represent an electrolyte with 30% of salt . The dotted lines are the corresponding polynomial curves . There is shown in the figure with the arrow that doubling of the current can be achieved by increasing the voltage by around 7V .

[0124] There is shown in figure 12 the relation between the current and the temperature of the electrolyte at a particular voltage . The amount of salt in the electrolyte is 1 % , the particular voltage is 5V . Since the electrolyte is brought to high temperature ( according to heating temperature profiles usually used in heated tobacco products ) it exhibits high conductivity and therefore , a voltage higher than safe contact level is not necessary (polynomial 2 order temperature relationship ) .

[0125] It is to be noted that the above has been explained based on the temperature profile shown in figure 6 . However, the same can be applied also to embodiments in which the heating of the electrolyte of the capacitor 160 during the vaping session VP is a combination of cycling between charging and discharging as shown with reference to figure 6 and heating by the external heater, as shown with reference to figure 7 .

[0126] In the following, an example of setting the voltage at the second value in an embodiment of the present invention is described . Here , the one or more associations of the one or more parameters may be stored as mathematical relations ( functions ) in the memory 50 .

[0127] For this example , it is assumed that the pressure change is such that it is associated with an extra amount of aerosol ( di f ference amount of aerosol ) of Img to be delivered during 2 s .

[0128] The product of glycerol electrolysis is formic acid and the number of electrons is 3 . This is given with the following equation :

[0129] C3H8O3— 8e~ + 8OH~ — 5H2O = 3CH2O2. ( 1 )

[0130] In this equation, CaHgOa is the chemical formula of glycerol and CH2O2 is the chemical formula of formic acid . The molar mass of glycerol is 92.09382 g / mol and its Faraday constant is 96485.33 As / mol.

[0131] Further, the following equation is applied:

[0132] Mass=Qvapour -Molar mass / (number of electrons • Faraday constant) (2)

[0133] Here, Mass denotes the difference amount of aerosol in mg (the above mentioned 1 mg) and Qvapour denotes the amount of electric charge (expressed in Coulombs or Ampere-seconds) consumed by electrolysis reaction (outcome of this reaction is mass of electrolyte mass that is vaporized) .

[0134] Form equation (2) it follows that:

[0135] Q aPour=Mass • number of electrons • Faraday constant / Molar mass (3)

[0136] Qvapour can be expressed as:

[0137] QvaPour=Current • vaporization time > (4)

[0138] As indicated above, the vaporization time in this example is 2 ms .

[0139] From the above, it follows that:

[0140] Current=Mass • number of electrons • Faraday constant / (Molar mass • vaporization time)... (5)

[0141] Introducing the above given values in equation (5) it follows that :

[0142] Current=l • 3 • 96485.33 / ( 93.09382 • 2 ) =1.571A. This is the current target value . In a next step a voltage ( second voltage value ) needs to be found to give this target current value .

[0143] I f at 260 ° C, the current at 5V is 0 . 744 A, the voltage would have to be increased by around 7V to 12V . It is to be understood that the amount the voltage would need to be increased may be calibrated for each consumable article 100 . This voltage refers to constant voltage charging . For cycling between charging and discharging, the maximum voltage would have to be increased even more . Still , considered voltage levels can be easily reali zed using commercially available boost converters , and the voltage does not need to go above the safe contact threshold . Therefore , the requirements for safety of the aerosol generating device 1 are also satis fied .

[0144] In one or more embodiments of the present invention, the association between each of the plurality of current target values with one of the plurality of temperatures of the electrolyte is a pre-determined association . The pre-determined association may be set at the manufacturing stage of the aerosol generating device 1 and / or during the learning phase when the user trains the aerosol generating device 1 .

[0145] In one or more other embodiments of the present invention, the association between each of the plurality of current target values with one of the plurality of temperatures of the electrolyte may be determined based on identi fication of the consumable article 100 . In case of particular manufacturing tolerances , or measurement errors or di f ferent age between consumable articles and / or the age of the aerosol generating device 1 as well as conditions af fecting the consumable article and / or the aerosol generating device , for example storing / holding conditions or environmental conditions during use ( for example low environment temperature when the aerosol generating device is used in winter conditions ) , the stored associations may not be accurate anymore . For this, the aerosol generating device 1 may comprise a current sensor. The current sensor may be one of the sensors of the sensor unit 40. The current sensor may be configured to measure the current during charging of the capacitor 160. The control unit 10 may be configured to obtain the measured current value and to adjust the selected second value based on the obtained measured current value.

[0146] For this, the control unit 10 may be configured to perform a closed loop control with one or more control loop parameters to adjust the selected second value based on the obtained measured current value.

[0147] Therefore, the control unit 10 may comprise an additional controller, for example a PID controller (a proportional- integral-derivative controller) that controls the output voltage (in a given voltage range) for obtaining the target current value. The initial output voltage value would be according to pre-determined or pre-defined calibration. The controller would just do the necessary adjustments to achieve the current setpoint .

[0148] There is shown in figure 13 the functional blocks of the control unit for performing this control. In the figure, r(t) is a current setpoint (e.g. 1A) , which is being obtained from the known relations between pressure change and current, as elaborated above. The process variable, y(t) , is actual measured current (e.g. 0.95A) . The u(t) is the output of the PID controller 16, which is the voltage e.g. 5V. The Kp, Ki and Kd are parameters of the controller that a skilled person in the art would set to achieve desired control loop dynamics. This controller 16 would be only activated once the second threshold is reached.

[0149] The control unit 10 may be configured to compare the measured current value y(t) with the target current value r(t) in the comparator block 17 and to adjust the selected second value based on the di f ference between the measured current value and the target current value .

[0150] It is also possible that during a particular number of operational cycles of the aerosol generating device the prestored associations are used, while after the particular number of operational cycles is exceeded, the above adj ustment is used .

[0151] Although detailed embodiments have been described, these only serve to provide a better understanding of the invention defined by the appended claims and are not be seen as limiting .

Claims

CLAIMS :1 . An aerosol generating device comprising : a consumable article adapted to be inserted in the aerosol generating device by a user, the consumable article comprising a capacitor, the capacitor comprising an electrolyte which when heated generates an aerosol for inhalation by the user ; a pressure change identi fication means for identi fying pressure change in the aerosol generating device , and a control unit configured to set a voltage for charging and / or discharging the capacitor to thereby control the heating of the electrolyte , wherein in response to the pressure change identi fication means identi fying that the pressure change exceeds a first threshold, the control unit is configured to set the voltage at a first value , and in response to the pressure change identi fication means identi fying that the pressure change exceeds a second threshold, the second threshold being higher than the first threshold, the control unit is configured to set the voltage at a second value .2 . The aerosol generating device according to claim 1 , wherein the second value is higher than the first value .3 . The aerosol generating device according to claim 1 or 2 , wherein in response to the pressure change identi fication means identi fying that the pressure change exceeds the first threshold, the control unit is configured to control , based on the voltage set at the first value , repeated chargingand discharging of the capacitor to thereby control the heating of the electrolyte.

4. The aerosol generating device according to any one of claims 1 to 3, wherein in response to the pressure change identification means identifying that the pressure change exceeds the second threshold, the control unit is configured to control, based on the voltage set at the second value, one of charging of the capacitor and repeated charging and discharging of the capacitor to thereby control the heating of the electrolyte.

5. The aerosol generating device according to any one of claims 1 to 4, wherein the control unit is configured to determine the second value based on the identified pressure change amount by the pressure change identification means and one or more associations of one or more parameters.

6. The aerosol generating device according to claim 5 further comprising a memory, the memory storing the one or more associations of the one or more parameters.

7. The aerosol generating device according to any one of claims 5 and 6, wherein one parameter is an amount of aerosol.

8. The aerosol generating device according to claim 7, wherein the amount of aerosol is the difference amount of aerosol between the amount of aerosol generated when the voltage is set at the first value to the amount of aerosol generated when the voltage is set at the second value.

9. The aerosol generating device according to claim 8, wherein the difference amount of aerosol is the difference amount of aerosol in a predetermined time period.

10. The aerosol generating device according to claim 8, wherein the memory stores a plurality of difference amounts of aerosol and a plurality of pressure change amounts, whereinin the memory each of the plurality of di f ference amounts of aerosol is stored in association with one of the plurality of pressure change amounts .11 . The aerosol generating device according to claim 10 , wherein the association between each of the plurality of di f ference amounts of aerosol with the corresponding one of the plurality of pressure change amounts is based on user preferences .12 . The aerosol generating device according to any one of claims 10 and 11 , wherein one parameter i s a target current value for charging and / or discharging the capacitor, wherein the memory stores a plurality of target current values , wherein in the memory each of the di f ference amounts of aerosol is stored in association with one of the target current values .13 . The aerosol generating device according to claim 12 , wherein the memory stores a plurality of second values , wherein each of the plurality of second values is stored in association with one of the target current values .14 . The aerosol generating device according to claim 13 , wherein the memory stores a plurality of temperatures of the electrolyte , wherein in memory each of the plurality of target current values is stored in an association with one of the temperatures of the electrolyte .15 . The aerosol generating device according to claim 14 , wherein the control unit is configured to select the second value from the memory based on identi fied pressure change amount by the pressure change identi fication means , the temperature of the electrolyte and the target current value associated to the temperature of the electrolyte .16 . The aerosol generating device according to claim 14 or 15 , wherein the association between each of the plurality of current target values with one of the plurality o ftemperatures of the electrolyte is a pre-determined association or is determined based on identi fication of the consumable article .17 . The aerosol generating device according to any one of claims 15 and 16 , further comprising a current sensor, the current sensor being configured to measure the current during charging of the capacitor, wherein the control unit i s configured to obtain the measured current value and to adj ust the selected second value based on the obtained measured current value .18 . The aerosol generating device according to claim 17 , wherein the control unit is configured to perform a closed loop control with one or more control loop parameters to adj ust the selected second value based on the obtained measured current value .19 . The aerosol generating device according to claim 18 , wherein the control unit is configured to compare the measured current value with the target current value and to adj ust the selected second value based on the di f ference between the measured current value and the target current value .

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