Aerosol Generation Device

TECHNICAL FIELD

Example aspects herein relate to aerosol generation from a consumable, and in particular to an aerosol generation device, a method for controlling an aerosol generation device and a computer program.

BACKGROUND

There are known devices used to heat or warm aerosolisable substances, in order to generate an aerosol. For example, aerosol generation devices, with known types such as atomizers, vaporizers, electronic cigarettes, e-cigarettes, cigalikes, etc. are used to heat aerosolisable substances as a reduced-risk or modified-risk device from conventional tobacco products.

A commonly available reduced-risk or modified-risk device is the heated substrate aerosol generation device or heat-not-burn device. Devices of this type generate an aerosol or vapor by heating an aerosol substrate that typically comprises moist leaf tobacco or other suitable aerosolisable material. Heating an aerosol substrate, but not combusting or burning it, releases an aerosol that comprises the components sought by the user but not the toxic and carcinogenic by-products of combustion and burning.

Typically, the aerosolisable substance is provided in an aerosol substrate which is included in consumable, and when the consumable is coupled to the device, the device can heat or warm the substrate to generate the aerosol.

SUMMARY OF THE DISCLOSURE

Consumables adapted for such aerosol generation devices are generally designed for a specific amount of use, e.g. until the aerosol substrate is depleted. Tobacco sticks are an example of consumables designed to have a limited or single use, meaning the tobacco stick should be discarded after it has been heated once.

Past the intended use, the consumable's structural integrity can no longer be guaranteed, due at least in part to a weakening as the moisture content of the aerosol substrate being reduced, and the consumable risks breaking down. This may disable the aerosol generation device or cause safety issues for example if the broken down consumable causes an electrical short or a flame (e.g. if it meets a heating element in the device).

Additionally, for tobacco sticks, the tobacco (which is the aerosol substrate) will have dried out, leading to the taste to be poor. A similar problem occurs for aerosol substrate not containing tobacco.

There is therefore a need to prevent the use of an already used consumable, thereby preventing the consumable from breaking whilst coupled to the device and degrade user experience, to improve the safety and reliability of aerosol generation devices.

According to a first example aspect disclosed herein, there is provided an aerosol generation device comprising: a receptacle for receiving a consumable comprising an aerosol substrate; a heating arrangement for heating the aerosol substrate; and a controller, the controller comprising: a monitoring unit for monitoring an observable indicative of a moisture content of the aerosol substrate during a heating of the aerosol substrate; a detection unit for detecting, based on the monitored observable, an indication that the moisture content is different from a predetermined moisture content; and a signaling unit for generating, based on the detected indication, a control signal for interrupting an operation of the device.

Accordingly, the aerosol generation device can recognize whether a consumable is a new consumable or a used consumable, based on the moisture content inferred from the observable, and the operation of the device can be interrupted if the consumable is not considered to be new, thereby improving safety and usability of the device.

Preferably, the monitoring unit is arranged for monitoring the observable by obtaining values of the observable at each of a plurality of time instants during the heating of the aerosol substrate.

Preferably, the aerosol generation device further comprises a temperature sensor for measuring a temperature of the heating arrangement, and the monitoring unit is arranged for obtaining from the temperature sensor a signal indicative of the temperature of the heating arrangement.

Preferably, the detection unit is arranged for detecting the indication based on a deviation of the observable from a corresponding predetermined profile; and the observable comprises at least one of a thermal profile of the device, a moisture profile related to the aerosol substrate and an electrical energy profile of the device, corresponding to a predetermined thermal profile, a predetermined moisture profile, and a predetermined electrical energy profile, respectively (i.e. the detection unit is arranged for detecting the indication based on: a deviation of the thermal profile of the device from the predetermined thermal profile, a deviation of the moisture profile related to the aerosol substrate from the predetermined moisture profile, and/or a deviation of the electrical energy profile of the device from the predetermined electrical energy profile).

Preferably, the observable comprises the thermal profile of the device, the predetermined thermal profile includes information regarding a temperature change for the heating of the aerosol substrate, from a first predetermined value to a second predetermined value over a first predetermined length of time; and the detection unit is arranged for detecting the indication if at least one of: the monitored thermal profile differs from the predetermined thermal profile by a predetermined thermal threshold or more; and the monitored thermal profile changes from the first predetermined value to the second predetermined value in less than a reference length of time (which may be predetermined), the reference length of time being less than or equal to the first predetermined length of time.

Preferably, the first predetermined value is one of an ambient temperature, an initial temperature of the aerosol substrate, and an initial temperature of the heating arrangement; and the second predetermined value is a temperature of the device at which an aerosol or vapor is generated from the aerosol substrate.

Preferably, the monitoring unit is arranged for monitoring the thermal profile by obtaining temperature values that are indicative of a temperature associated with one of the device and the aerosol substrate at each of a plurality of time instants during the heating of the aerosol substrate, and the detection unit is arranged for detecting the indication if at least one of the temperature values differs from a corresponding one of reference values by the predetermined thermal threshold or more, the reference values being determined based on the information of the temperature change.

Preferably, the monitoring unit is arranged for obtaining, for each temperature value, an associated measure of time between a time at which the heating of the aerosol substrate is initiated and a time at which the temperature indicated by the temperature value is reached; and the detection unit is arranged for determining, for each temperature value, a point in the first predetermined length of time based on the associated measure of time, and determining the reference value as the temperature specified by the information regarding the temperature change at the determined point.

Preferably, the monitoring unit is arranged for: measuring a value indicative of an electrical power in the device during the heating of the aerosol substrate and monitoring the electrical energy profile by accumulating the value indicative of the electrical power during the heating of the aerosol substrate. The predetermined electrical energy profile includes information indicative of a predetermined accumulated power value; and the detection unit is arranged for detecting the indication if the accumulated value indicative of the electrical power differs from the predetermined accumulated power value, by a predetermined electrical energy threshold or more.

Preferably, the monitoring unit is arranged for measuring the value indicative of the electrical power based on at least one of a current output from a battery coupled to or in the device, and a current provided to the heating arrangement.

Preferably, the aerosol generation device is arranged for controlling a temperature of the heating arrangement by controlling at least one switching element using a pulse width modulation, and the monitoring unit is arranged for monitoring the electrical energy profile by calculating an amount of electrical energy used for the heating of the aerosol substrate based on lengths of time during which the pulse width modulation cause the at least one switching element to be on.

Preferably, the monitoring unit is arranged for calculating a cumulative length of time during which the at least one switching element is on, and to calculate the amount of electrical energy based on the cumulative length of time.

According to a second example aspect disclosed herein, there is provided method for controlling an aerosol generation device comprising a receptacle for receiving a consumable, the consumable comprising an aerosol substrate, and a heating arrangement for heating the aerosol substrate, the method comprising: monitoring an observable indicative of a moisture content of the aerosol substrate during a heating of the aerosol substrate; detecting, based on the monitored observable, an indication that the moisture content is different from a predetermined moisture content; and generating, based on the detected indication, a control signal for interrupting an operation of the device.

According to a third example aspect herein, there is provided a computer program comprising instructions which, when executed by one or more processors, cause the one or more processors to perform a method according to the second example aspect above.

According to a further example aspect herein, there is provided a non-transitory storage medium storing the computer program of the third example aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG. 1 is a schematic view showing an example of an aerosol generation device and a consumable;

FIG. 2 is a block diagram showing an example of electrical components of an aerosol generation device;

FIG. 3 shows an example of a monitored thermal profile of the device and a predetermined thermal profile during the heating of the aerosol substrate;

FIG. 4A shows an example of a predetermined moisture profile during the heating of the aerosol substrate and a subsequent use of the consumable;

FIG. 4B shows an example of a predetermined electrical energy profile during the heating of the aerosol substrate;

FIG. 4C shows an example of predetermined profiles during the heating of the aerosol substrate;

FIGS. 5A and 5B show examples of monitored thermal profile and predetermined thermal profile during the heating of the aerosol substrate;

FIG. 6 is a block diagram showing an example of electrical components of an aerosol generation device;

FIG. 7 shows an example of a duty cycle of a signal used to control switching element(s) and a temperature of a heating arrangement during the heating of the aerosol substrate; and

FIG. 8 shows a method for controlling an aerosol generation device.

DETAILED DESCRIPTION

Although example embodiments will be described below, it will be evident that various modifications may be made to these example embodiments without departing from the broader spirit and scope of the invention. Accordingly, the following description and the accompanying drawings are to be regarded as illustrative rather than restrictive.

In the following description and in the accompanying figures, numerous details are set forth in order to provide an understanding of various example embodiments. However, it will be evident to those skilled in the art that embodiments may be practiced without these details.

FIG. 1 is a schematic diagram showing an example of an aerosol generation device 100 according to an example embodiment, and a consumable 10 for use with the aerosol generation device 100. The consumable 10 comprises an aerosol substrate 12. The aerosol generation device 100 includes a receptacle 110 for receiving the consumable 10, a heating arrangement 120 for heating the aerosol substrate 12, and a controller 130.

The consumable 10 is designed for a single use (i.e. that should only be heated once to generate aerosol substrate). In the example shown on FIG. 1, the consumable 10 is a tobacco stick forming a tubular region with an aerosol substrate 12 and an outer layer of material, such as paper, foil or other flexible planar material, which may be used to provide additional structural integrity to the hold the aerosol substrate in place. As such, the consumable 10 may broadly resemble a cigarette.

However, the consumable 10 is not limited to any particular form, and any form allowing the consumable 10 to be received by the receptacle 110 may be used. Additionally, the consumable 10 need not have the outer layer of material, for example when the aerosol substrate 12 may have sufficient structural integrity to be used on its own, or if a material embedded in the aerosol substrate 12 provides the required level of structural integrity. In some designs, filters, vapor collection regions, cooling regions, and other structure may also be included in the consumable 10.

The aerosol substrate 12 may be provided as a solid or paste type material in shredded, pelletized, powdered, granulated, strip or sheet form, optionally a combination of these. Equally, the aerosol substrate may include a fluid (e.g. liquid or gel). The aerosol substrate may include tobacco, for example in dried or cured form, in some cases with additional ingredients for flavoring or producing a smoother or otherwise more pleasurable experience. Depending on the materials included in the aerosol substrate, the consumable may be defined as a tobacco stick, or the aerosol substrate may be defined as a flavor release medium. In some examples, the aerosol substrate 12 such as tobacco may be treated with a vaporizing agent. The vaporizing agent may improve the generation of vapor from the aerosol substrate. The vaporizing agent may include, for example, a polyol such as glycerol, or a glycol such as propylene glycol. In some cases, the aerosol substrate may contain no tobacco, or even no nicotine, but instead may contain naturally or artificially derived ingredients for flavoring, volatilization, improving smoothness, and/or providing other pleasurable effects. The aerosol substrate 12 such as tobacco may comprise one or more humectants to retain moisture, such as glycol(s).

Before use, the aerosol substrate 12 has predetermined moisture content, which may depend on its design, shape, packaging, type, flavor, etc. As used herein, the moisture content refers to the amount of water and any other humectants that may be present in the aerosol substrate 12, and may be defined by mass (e.g. a gravimetric water content), by volume (e.g. a volumetric water content) or any other measurable physical quantity of the aerosol substrate. It would be understood that in practice, the moisture content may vary slightly from the predetermined value, and therefore the expression “a predetermined value” may instead be understood to indicate a range, which may be defined about the predetermined value (e.g. ±2% around the predetermined value) or with a lower and an upper limit. Typically, the moisture content of a tobacco stick before use (i.e. the predetermined moisture content) is a value in or around the range of 13%-14.3%. After use, the moisture content of the tobacco stick typically decreases to a value in or around the range of 6%-8%. However, the present invention is not limited in this aspect, and the predetermined moisture content may be a value higher than 14.3%, or a value lower than 13%.

The receptacle 110 receives the consumable 10 to be used (i.e. the consumable 10 is placed in/on/near the receptacle 110, in a predetermined position/orientation relative to the aerosol generation device 100).

The heating arrangement 120 is arranged for heating the consumable 10 when it is received in the receptacle 110.

In the example shown on FIG. 1, the heating arrangement 120 comprises a heating chamber 122 (e.g. an oven) forming a space, the receptacle 110 providing an aperture into the heating chamber 122 through which the consumable 10 is inserted. The receptacle 110 further includes securing means (not shown) for releasably securing the consumable 10 in position, although it would be understood that separate securing means may not be necessary, for example if the heating chamber and/or the heater are arranged for securing the consumable when in use.

However, the receptacle 110 is not limited to this form, and the receptacle 110 may be of any other shape capable of receiving the consumable and holding the consumable in place whilst the aerosol substrate is heated. For example, the receptacle 110 and the consumable 10 may comprise corresponding connectors (e.g. plug and socket type of mechanical connectors, magnets of opposite polarity located in the receptacle 110 and the consumable 10, etc.).

The heating arrangement 120 is arranged for heating the aerosol substrate 12, e.g. by using a heating element in contact with or in proximity to the aerosol substrate, by heating a thermally conductive element (e.g. a wick) in contact with or in proximity to the aerosol substrate, by induction heating of a coil or other electrically conducting object in the consumable 10 which is in contact with or which can radiate thermal energy to the aerosol substrate 12, etc. The heating arrangement 120 is not limited to these examples, and any means to heat the aerosol substrate 12 can be used.

In the example shown on FIG. 1, the heating arrangement 120 includes a heater 124 comprising a coil which is provided on the surface of the heating chamber 122 for heating the heating chamber, thereby heating the aerosol substrate 12 of the consumable 10 received within the heating chamber 122. However, it should be understood that other types of heating arrangement may be used, and the heater may be of any other configuration.

It would be further understood that the generated aerosol can be used by being directed towards an output, such as mouthpiece (not shown), from which a user of the aerosol generating device can inhale the aerosol. By way of non-limiting examples, the consumable 10 may include a region acting as the mouthpiece and which may protrude from the receptacle 110 when the consumable 10 is received by the receptacle 110. Alternatively, the aerosol generation device 100 may include a separate mouthpiece coupled to the heating chamber 122 such that the aerosol may be directed towards the mouthpiece (e.g. by inhalation of the user or by action of a ventilation device in the aerosol generation device).

The controller 130 comprises a monitoring unit 132, a detection unit 134 and a signaling unit 136.

The monitoring unit 132, the detection unit 134 and the signaling unit 136 may be implemented as software, hardware, or a combination thereof. Specifically, in some examples, the controller 130 may comprise one or more processor (e.g. a single/multiple core CPU, a microprocessor etc.), one or more working memories (e.g. random-access memory, RAM, flash memory etc.) and one or more non-volatile instructions stores (e.g. read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), flash memory, etc.) storing computer-readable instructions, whereby the processor(s) executing the computer-readable instructions in the instruction store(s) function as the monitoring unit 132, the detection unit 134 and the signaling unit 136. In other examples, the monitoring unit 132, the detection unit 134 and the signaling unit 136 may be implemented as hardware components each including separate circuitry, such as integrated circuitry (IC), in which case data obtained by each unit may be transmitted to other unit(s) by way of communication channels (e.g. dedicated signal lines or bus), by storing data in memory accessible to other units.

In the example shown on FIG. 1, the controller 130 is a microcontroller (MCU), functioning as the monitoring unit 132, the detection unit 134 and the signaling unit 136.

The monitoring unit 132 is for monitoring an observable indicative of a moisture content of the aerosol substrate during a heating of the aerosol substrate. Here, the observable is a physical property that may be sensed/detected via one or more sensors (or derived based on data obtained by the sensor(s)) and which indicates the moisture content of the aerosol substrate.

By way of non-limiting examples, the observable may be a moisture level that is measured in the heating chamber 122 using a moisture sensor, a dielectric constant measured across a section of the aerosol substrate 12, a temperature of the aerosol substrate at a given time instant during the heating, a rate of temperature change of the aerosol substrate during the heating, an amount of energy used to for heating the aerosol substrate, an apparent load perceived by an induction heating coil in the heating arrangement 120 when the consumable is received by the receptacle, or any other observable which is indicative of the moisture content in the aerosol substrate 12. In some examples, the observable may be a plurality of physical properties (for example a combination of the above-explained examples) that can be monitored.

In the example shown on FIG. 1, the observable comprises a temperature of the heating arrangement 120. Specifically, the heating arrangement 120 comprises a temperature sensor 126 (e.g. a thermistor, thermocouples, resistance-based temperature detectors, etc.) which is communicatively coupled to the controller 130, and the monitoring unit 132 is configured to obtain a temperature from the temperature sensor 126, at one or more time instants during the heating of the aerosol substrate. The temperature sensor 126 may also be used to control the temperature of the heater 124, as explained further below. For example, the monitoring unit 132 may obtain a value of the temperature at the beginning of the heating of the aerosol substrate 12, and periodically obtain a value of the temperature (e.g. every second) during the heating of the aerosol substrate 12. As another example, the monitoring unit 132 may obtain a value of the temperature at a single time instant relative to the beginning of the heating of the aerosol substrate 12 (e.g. 7 seconds).

However, it would be understood that in other examples, the temperature sensor 126 may be omitted. For example, a resistance of the heater may be determined (e.g. with voltage and current sensor), and a temperature of the heater may be determined based on a known relationship between the resistance and the temperature of the heater. For brevity, methods for determining the resistance of the heater, or for determining a temperature of the heater based on its resistance which will be known to the skilled person will not be described here.

The detection unit 134 is for detecting, based on the monitored observable, an indication that the moisture content is different from a predetermined moisture content. In other words, the detection unit 134 obtains value(s) of the observable monitored by the monitoring unit 132 and detects the indication based on the value(s) of the monitored observable.

The detection unit 134 may, for example, detect that the moisture content is different from the predetermined moisture content if the value of the monitored observable falls outside a predetermined range for the value of the monitored observable (e.g. the value is lower than a first predetermined threshold, the value is not between the first predetermined threshold and a second predetermined threshold, or the value is higher than the second predetermined threshold). In such examples, it would be understood that the predetermined range may be defined by a single threshold (i.e. a lower threshold defining the predetermined range as all values equal to or higher than a threshold, or a higher threshold defining the predetermined range as all values equal to or lower than the threshold) or by a lower and a higher threshold.

In the example shown on FIG. 1, the detection unit 134 is arranged for detecting the indication that the moisture content of the aerosol substrate is different from the predetermined moisture content if a temperature value obtained by the monitoring unit 132 at a time instant less than 13 seconds from the beginning of the heating of the aerosol substrate 12 is equal to or higher than 120° C. As explained in more detail with reference to FIG. 3 below, this indicates that the moisture content of the aerosol substrate 12 is different than (in this case, less) the predetermined moisture content.

However, it will be understood that this is merely an example of the detection of the indication, and the present invention is not limited to this example. The present example embodiment may be used with any other detection described herein or derivable from the present disclosure, and in particular those described in connection with FIGS. 4A, 4B, 4C, 5A and 5B below.

The signaling unit 136 is for generating, based on the detected indication, a control signal for interrupting an operation of the aerosol generation device 100. In other words, the signaling unit 136 obtains a notification when the detection unit 134 detects the indication that the moisture content of the aerosol substrate 12 is different from the predetermined moisture content, and the notification causes the signaling unit to generate the control signal.

For example, the generated control signal may be transmitted to the heating arrangement 120 to indicate that the heating of the aerosol substrate 12 is to be interrupted, a signal to disable the heating arrangement 120, a signal to the electrical power source 140 to interrupt a supply of electrical power to the heating arrangement 120, or a signal to the electrical power source 140 to disable the supply of electrical power to the aerosol generation device 100 entirely, etc. The control signal may interrupt the operation, for example, by causing a circuit breaker to trip, or power to be diverted away from a component to be disabled (e.g. by shorting a component). Although the term control signal is used in the singular form, this should be understood to be a reference to at least one control signal that may control the operation of various components in the aerosol generation device.

In each of these cases, the generation of the control signal cause the heating of the aerosol substrate to be interrupted.

In the example shown on FIG. 1, the signaling unit generates a first control signal to disconnect the heater 124, thereby stopping the heater 124 from heating the aerosol substrate 12. In cases where the aerosol generation device includes a display screen, the signaling unit may generate a second control signal to control the display screen to display a message notifying the user of the aerosol generation device that the consumable does not have the required moisture content. However, it would be understood that other means of notifying the user, such as haptic feedback, may be used instead or in addition to the display of the message.

Accordingly, the heating of a consumable having an inadequate moisture content is prevented, and the safety/reliability of the aerosol generation device is improved.

Although not shown on FIG. 1, it would be understood that the aerosol generation device 100 may comprise additional components such as an electrical power source integral to the aerosol generation device or a connection to an external electrical power source, control circuitry to control the supply of electrical power from the electrical power source to the controller 130 and/or the heating arrangement 120, a frame to hold the various components together, a display screen to notify a user of the aerosol generation device with information relating to the device or the consumable, buttons or other controls enabling the user to turn on/off or control the aerosol generation device etc.

An example of electrical components of the aerosol generation device 100 according to the present example embodiment will be described, with reference to FIG. 2.

In the example shown on FIG. 2, the aerosol generation device 100 comprises the heating arrangement 120, the controller 130 (e.g. an MCU), an electrical power source 140, and a charging arrangement 150.

The electrical power source 140 supplies electrical power to other components of the aerosol generation device 100, including the controller 130 and the heating arrangement 120.

In the example shown on FIG. 2, the electrical power source 140 comprises a battery 142 (e.g. a secondary battery such as a lithium-ion, nickel-metal hybrid or a non-rechargeable battery) and a battery protection circuit 144. However, it would be understood that the battery protection circuit 144 may be omitted in some cases (for example with batteries not requiring a protection circuit), or the electrical power source 140 may instead be a connector couplable to an electrical power source external to the aerosol generation device 100 (e.g. a mains electricity power, a DC 5V electrical power source etc.), and which transfers the electrical power from the external source to the components of the aerosol generation device 100.

The charging arrangement 150 is for supplying electrical power to re-charge the battery 142, from an electrical power source that is electrically coupled to the aerosol generation device. However, it would be understood that, in cases where the electrical power source 140 does not include a rechargeable element (e.g. the battery 142 is not rechargeable or is omitted), the charging arrangement 150 may be omitted.

In the example shown on FIG. 2, the charging arrangement 150 comprises a connector 152 couplable to an external electrical power source and a charging IC 154 for controlling the supply of power from the external electrical power source to the battery 142, optionally comprising a transformer for transforming the voltage/current characteristics of the electrical power supplied by the external power source.

In the example shown on FIG. 2, the heating arrangement 120 comprises a converter 128, the heater 124, the temperature sensor 126 and a switching element 129.

The converter 128 is arranged for converting the electrical power received from the electrical power source 140 into an electrical power suitable to heat the aerosol substrate. For example, the converter may be a booster circuit for increasing the voltage of the electrical power received from the electrical power source 140 to a higher level voltage. However, it would be understood that in some cases, the electrical power output by the electrical power source need not be converted to heat the aerosol substrate, in which case the converter 128 may be omitted.

In the example shown on FIG. 2, the converter 128 is a booster increasing a 3.3V voltage output by the electrical power source 140 to a voltage in the range of 3.8 to 4.3V, which is controllable by the user of the aerosol generation device 100 via buttons. As shown on FIG. 2, the booster may be enabled or disabled by the controller 130, to controllably provide the boosted electrical power to the heater 124 (when enabled). It would be understood however, that the voltage level or range described here are exemplary, and the booster is not limited in respect of the voltage received from the electrical power source 140 or the voltage/range of voltage output by the booster (converter 128).

The heater 124 is arranged for heating the heating chamber (not shown). In the example shown on FIG. 2, the heater 124 is a coil. However, it would be understood that the heater is not limited to this form and may be any other type of heater, whether conduction-based (e.g. coil-and-wick combination), or convection-based.

The temperature sensor 126 provides a temperature of the heating chamber 122 to the controller 130, as explained above with reference to FIG. 1.

The switching element 129 allows the controller 130 to control the temperature in the heating chamber. The switching element 129 may be a transistor, such as Field-effect transistors (FET) (e.g. Si MOSFETS, GaN MOSFETs, SiC MOSFETs, etc.), a Bipolar Junction Transistor (BJT), insulated-gate bipolar transistor (IGBT), thyristors, or other known types of switching element. Although the switching element 129 is referred to as a single switching element, it may comprise more than one switching element arranged in series and/or cascade, and reference to the switching element 129 should therefore be interpreted as a reference to at least one switching element.

In the example shown on FIG. 2, the switching element 129 is a MOSFET arranged in series between the heater and a terminal of the electrical power source, so that an electrical power loop may be controllably formed between the electrical power source and the heater (and including other components of the heating arrangement 120, such as the converter 128), by controlling the state of the MOSFET. Specifically, in the example shown on FIG. 2, the controller 130 obtains the temperature from the temperature sensor 126. The sensed temperature is input into a PID (Proportional, Integral, Derivative) control loop implemented on the controller 130, and the PID control loop outputs a value based on the difference between the sensed temperature and the desired temperature, the output of the PID control loop being compared to a pulse signal and converted into a pulse-width modulation (PWM) signal for controlling the state of the MOSFET 129 (i.e. the PWM signal is applied to the gate of the MOSFET 129).

For brevity, further details of the control loop and the control of the switching element 129 that would be known to the skilled person are omitted. However, it should be understood that the controller is not limited to the use of a PID control loop and/or controlling the switching element with a PWM signal, and any other known type of control loop, including PI− or P− control loop or signal to control the switching element may be implemented instead.

FIG. 3 shows an exemplary temperature of the heating arrangement 120, and in particular of the heating chamber 122 during a heating of the aerosol substrate. On FIG. 3, the heating of an aerosol substrate having the predetermined moisture content (e.g. a new consumable) is shown with a solid line, and heating of an aerosol substrate having no or little moisture content (e.g. a previously used consumable) is shown with a dashed line.

The heating arrangement 120 is arranged for heating the aerosol substrate 12 from an initial (e.g. an ambient) temperature to a higher temperature typically in the range 150° C. to 300° C. During the heating of the aerosol substrate, there is normally no substantial release of aerosol until the higher temperature is reached.

The heating of the aerosol substrate to that higher temperature causes the release of an aerosol as a result of the volatilizing, atomizing and/or vaporizing particles in the substrate. In the example shown on FIG. 3, the aerosol substrate is heated to a temperature around 230° C., although this is a non-limiting example and any temperature allowing the aerosol to be generated from the substrate can be used instead.

Once heated, the aerosol substrate may be maintained at or around a desired temperature if the generation of the aerosol is to continue. In some cases, this second phase may last for an amount of time that may be predetermined (e.g. until a predetermined amount of time is reached, such as 5 seconds), or an amount of time ending upon occurrence of an event (e.g. until the user stops using the aerosol generation device, the aerosol substrate is depleted, etc.). However, the aerosol substrate need not be maintained at this higher temperature, such as when only a small amount of aerosol is desired.

FIG. 3 only shows the heating of the aerosol substrate and the beginning of the use of the consumable (which can also be called a session) during which the user may inhale the generated aerosol. Although not shown on FIG. 3, it would be understood that once heated, the consumable may be maintained at the higher temperature for a few minutes (e.g. 4-5 minutes). Typically, towards the end of a session (e.g. 270 seconds from the start of heating of the aerosol substrate) the heater is turned off, and the session ends shortly after (e.g. 290 seconds from the start of heating of the aerosol substrate). At the end of the session, the consumable can be uncoupled from the aerosol generation device and discarded.

As apparent from FIG. 3, the level of water in the new consumable leads to a period of time when the temperature reaches about 100° C. during which the temperature does not substantially increase while the water evaporates (e.g. a “plateau”). Therefore, the consumable having lower moisture content will not have the same plateau and reach a temperature above 100° C. faster. Although the example of water is shown on FIG. 3, it should be understood that the detection unit 134 is not limited to detecting the absence of water. For example, in cases where the aerosol substrate 12 comprises humectants or other evaporable substances, the heating of the aerosol substrate 12 would lead to additional periods where the temperature does not substantially increase around the boiling point of the humectant/evaporable substance (e.g. in cases where the aerosol substrate 12 comprises propylene glycol, the temperature would briefly remain around 188° C., the boiling point of propylene glycol), and the reduced level or the absence of the humectant/evaporable substance can be detected based on the difference rate of increase of temperature, or the length of time required for the temperature to increase by a specific amount.

Thus, whether a consumable is new or used may be detected based on measured information indicating the moisture content of the aerosol substrate during the heating of the aerosol substrate.

In an example embodiment, the observable comprises at least one of a thermal profile of the device, a moisture profile related to the aerosol substrate and an electrical energy profile of the device. The monitoring unit 132 is arranged for monitoring at least one of the thermal profile, the moisture profile and the electrical energy profile of the device, during the heating of the aerosol substrate. In other words, the thermal profile, the moisture profile and the electrical energy profile of the device are profiles for the heating of the aerosol substrate.

As used herein, the term profile includes a value of the observable at one or more time instants during the heating of the aerosol substrate. The time may be defined relative to a start of the heating of the aerosol substrate, or relative to a time where the observable has reached a specific value (e.g. the heating arrangement 120 or aerosol substrate 12 has reached as specific temperature). Accordingly, a profile that includes a value of the observable at two or more time instants defines a change in the value of the observable over a time period between two of the time instants. A profile may, in some cases, define a function of the temperature over time during the heating of the aerosol substrate.

For example, the thermal profile may include a temperature value related to the aerosol substrate 12 obtained at one or more time instants during the heating of the aerosol substrate 12, such as a temperature of the aerosol substrate 12 itself, or a temperature of a component of the aerosol generation device 100 indicating the temperature of the aerosol substrate (e.g. the temperature of the heating chamber 122, as described above with reference to FIGS. 1 and 3).

The moisture profile includes a value indicating a moisture obtained (e.g. using a moisture or humidity sensor) from the aerosol generation device 100 (e.g. a moisture level in the heating chamber 122) or from the aerosol substrate 12, at one or more time instants during the heating of the aerosol substrate 12.

The electrical energy profile of the device includes a value indicating an electrical energy used during the heating the aerosol substrate 12 obtained at one or more time instants during the heating of the aerosol substrate 12. This may represent, for example, the electrical energy used by the heating arrangement 120 or by the heater 124 to heat the aerosol substrate, or it may alternatively represent the electrical energy used by more, or all, components of the device during the heating of the aerosol substrate. The value be obtained my measuring the energy output from the electrical power source 140 (or an external power source), or the energy provided to the heater 124 may be measured (e.g. by way of a shunt resistor in series with the heater 124 and a current measuring circuit in parallel with the shunt resistor). The value obtained by the monitoring unit 132 may indicate the electrical energy used at that time instant (e.g. the instantaneous energy) or may indicate a cumulative amount of electrical energy used over a period of time (e.g. from the beginning of the heating of the aerosol substrate 12 up to the time instant).

The detection unit 134 is arranged for detecting the indication based on a deviation of the observable from a corresponding predetermined profile. A predetermined profile may define a predetermined value of the observable for one or more time instants during a heating of the aerosol substrate 12, that is expected when the aerosol substrate 12 has substantially the predetermined moisture content. The predetermined profile may be defined for example as a function of the observable over time. The predetermined profile may be stored, for example, in a memory on the aerosol generation device 100 that is accessible to the detection unit 134.

The detection unit 134 is arranged for detecting the indication based on a comparison of the value of the observable obtained by the monitoring unit 132, and a value of the observable derived from the predetermined profile.

For example, the detection unit 134 may be arranged to detect the indication if a difference between the value(s) obtained by the monitoring unit 132 and the corresponding value(s) in the predetermined profile is equal to or greater than a predetermined threshold, which may be the same for all time instants, or may be set differently for each time instant.

With reference to FIGS. 3, 4A, 4B and 4C, examples of predetermined profiles according to the present example embodiment will be explained.

The solid line shown on FIG. 3 is an example of a predetermined thermal profile, defining the change in temperature of the heating chamber 122 during the heating of the aerosol substrate 12. However, it would be understood that the predetermined thermal profile is not limited to this as it may be any temperature that is indicative of the temperature of the aerosol substrate 12, such as the temperature of the aerosol substrate 12 itself, the temperature of the consumable 10, or another component of the heating arrangement 120 or the aerosol generation device 100.

FIG. 4A shows an example of a predetermined moisture profile which defines a predetermined moisture level in the heating chamber 122 during the heating of the aerosol substrate 12 and during the subsequent use of the consumable. However, the present invention is not limited to a predetermined moisture profile defining the moisture level in the heating chamber. Instead, the predetermined moisture profile could define a moisture level in the aerosol substrate 12 itself (corresponding to the moisture level expected to be measured, for example, by a moisture sensor in contact with the aerosol substrate 12 when the consumable is received by the receptacle 110).

As shown on FIG. 4A, the moisture level is predetermined to start at an initial value (e.g. around 13%) and to decrease during the heating of the aerosol substrate to a lower value (e.g. 10%) as the water and any humectants and other substances in the aerosol substrate 12 evaporate. After the aerosol substrate 12 is heated to the higher temperature at which the aerosol is generated, the moisture level continues to reduce during the use of the consumable.

FIG. 4B shows an example of a predetermined electrical energy profile, which defines a cumulative amount of energy used during the heating of the aerosol substrate 12. In the example shown on FIG. 4B, the cumulative amount of energy output from the electrical power source 140 is predetermined to increase with a substantially constant rate for the first 10 seconds of the heating to a value of about 180 Joules, to and to increase with a relatively lower rate thereafter. As explained above, the predetermined electrical energy profile is not limited to define the cumulative electrical energy output from the electrical power source 140, and may instead be an instantaneous energy provided to the heater 124 at different time instants, etc.

In the present example embodiment, the monitoring unit 132 may be arranged for monitoring one or more of the thermal profile such as the one shown on FIG. 3, the moisture profile such as the one shown on FIG. 4A, and the electrical energy profile such as the one shown on FIG. 4B. The detection unit 134 is arranged for detecting the indication based on a deviation that is present in one of these profiles from a corresponding predetermined profile, or it may be arranged for detecting the indication if a respective deviation is present in two or all of the monitored profiles, the deviations detected in each profile indicating that the moisture content in the aerosol substrate is different from a predetermined moisture content.

For example, if the monitoring unit 132 is arranged for monitoring the thermal profile shown on FIG. 3, it may detect an indication if the monitored temperature at t=100 s is substantially higher than 130° C., if the monitoring unit 132 is arranged for monitoring the moisture profile shown on FIG. 4A, it may detect an indication if the monitored moisture content at t=0 s is lower than 10%, and/or if the monitoring unit 132 is arranged for monitoring the electrical energy profile shown on FIG. 4B, it may detect an indication if the monitored cumulative energy at t=10 s is lower than 160 J (indicating that no/less energy will have been used to evaporate water and/or other humectants in the aerosol substrate 12).

Alternatively, the predetermined profile may instead comprise one or more associations, where each association is between a time instant and a predetermined value of the observable at that time instant, for example as shown on FIG. 4C.

In these cases, the detection unit 134 is arranged to compare the values obtained by the monitoring unit 132 at each time instant with the associated predetermined value.

Although FIG. 4C shows the predetermined profiles in a table form, it would be understood that the table form is for illustrative purposes, and the associations may be in any other suitable form.

In the example shown on FIG. 4C, the predetermined temperature profile defines a first association between a time instant t=5 s and the predetermined value of 100° C. for the temperature, a second association between the time instant t=8 s and the predetermined value of 150° C., a third association between the time instant t=13 s and the predetermined value of 230° C., and so on for the time instants t=100 s, 150 s, 200 s, 270 s and 290 s, each associated with the predetermined value of 230° C. Similarly, the predetermined moisture profile defines associations between time instants and predetermined values for the moisture level (time instant t=0 s and 13%; time instant t=5 s and 12%; time instant t=8 s and 11%; time instant t=13 s and 10%; time instant t=100 s and 9%; time instant t=150 s and 8%; time instant t=200 s and 7%; time instant t=270 s and 6%; and time instant t=290 s and 6%;). The predetermined electrical energy profile defines associations between time instants and a predetermined value for the electrical energy (time instant t=0 s and 0 J; time instant t=5 s and 90 J; time instant t=8 s and 150 J; time instant t=13 s and 185 J; time instant t=100 s and 405 J; time instant t=150 s and 530 J; time instant t=200 s and 660 J; time instant t=270 s and 840 J; and time instant t=290 s and 840 J).

Although each predetermined profile in the example shown on FIG. 4C defines a plurality of associations, it would be understood that one or more of the predetermined profile may instead include only one association. For example, the predetermined electrical energy profile may define a single association between a time instant and a predetermined value for the electrical energy, such as t=13 s and 185 J. In addition, although two or more of the predetermined profiles may define associations for the same time instants, as in the example shown on FIG. 4C, each of the predetermined profile may instead define one or more associations with mutually exclusive time instant(s) (e.g. a first predetermined profile may define an association using a time instant t=t1, and a second predetermined profile may define an association using a second time instant t=t2, where t2 is different from t1).

The exemplary predetermined profiles shown on FIG. 4C include associations for time instants during the heating of the aerosol substrate, and during the subsequent use of the consumable (during which the aerosol substrate is maintained at the temperature at which the aerosol substrate is generated). However, it would be understood that the predetermined profiles need not include any association for time instants past the moment where the aerosol substrate reaches the higher temperature. For example, as the aerosol substrate is expected to reach the temperature of 230° C. at t=13 s, the associations defined in the predetermined profiles for the time instants t=100 s, 150 s, 200 s, 270 s and 290 s may be omitted.

Optionally, the detection unit 134 may be arranged to determine, when the monitoring unit 132 obtains a value for a time instant that does not have an associated predetermined value, a corresponding value based on the associations defined in the predetermined profile, such as by way of a regression analysis (e.g. interpolation/extrapolation), curve fitting, etc.

Accordingly, the indication that the aerosol substrate 12 does not have the predetermined moisture content may be more accurately detected whilst reducing the resources required for keeping the predetermined profile.

In an example embodiment the observable comprises the thermal profile of the device. Thus, the monitoring unit 132 is arranged for monitoring a thermal profile of the device. The observable may, optionally, also comprise the moisture profile and/or the electrical energy profile described herein.

In the present example embodiment, the predetermined thermal profile includes information regarding a temperature change for the heating of the aerosol substrate, from a first predetermined value to a second predetermined value over a first predetermined length of time. The first predetermined value may be, for example, the first predetermined value is one of an ambient temperature (i.e. a temperature of the environment around the aerosol generation device 100), an initial temperature of the aerosol substrate, or an initial temperature of the heating arrangement 120 (e.g. of the heating chamber 122 or the heater 124). The second predetermined value may be, for example, a temperature at which an aerosol or vapor is generated from the aerosol substrate. Alternatively, the first predetermined value may be a value that is higher than typical ambient temperature (e.g. 50° C.), therefore reducing effects of variations due to different ambient/initial temperatures of the aerosol substrate. Similarly, the second predetermined value may be a value that is lower than the temperature at which an aerosol or vapor is generated from the aerosol substrate (e.g. 170° C.), therefore reducing risks that the consumable 10 loses its structural integrity due to heating.

In the present example embodiment, the detection unit 134 is arranged for detecting the indication if: the monitored thermal profile differs from the predetermined thermal profile by a predetermined thermal threshold or more; and/or, if the monitored thermal profile changes from the first predetermined value to the second predetermined value in less than a predetermined reference length of time, the predetermined reference length of time being less than or equal to the first predetermined length of time.

In other words, if a difference between one or more of the values obtained by the monitoring unit 132 and the corresponding value(s) defined in the predetermined profile is greater than the predetermined thermal threshold, the detection unit 134 detects the indication. Here, the predetermined threshold may be a number of degrees (e.g. 2° C., 3.5° C., 5° C., etc.) or a percentage of the predetermined value (e.g. 1.0%, 3%, 5.5%).

However, it would be apparent that the detection unit 134 may be arranged to detect the indication if at least two or more of the values obtained in the monitored thermal profile differ from corresponding values derived from the predetermined thermal profile. By relying on more comparisons, risks of an incorrect detection that the aerosol substrate 12 does not contain the predetermined moisture content may be reduced. Similarly, requiring that both individual value(s) in the monitored thermal profile differ substantially from their corresponding values in the predetermined thermal profile (i.e. by the predetermined thermal threshold or more), and that a change in the monitored thermal profile occurs substantially faster than in the predetermined threshold profile (i.e. in less than the corresponding reference length of time) may avoid an incorrect detection that the aerosol substrate 12 does not contain the predetermined moisture content.

Additionally or alternatively, if the monitoring unit 132 determines that a difference between a value of the temperature obtained at a first time instant and a value of the temperature obtained at a second time instant is equal to or greater than the difference between the second predetermined value and the first predetermined value, and the length of time between the first time instant and the second time instant is equal to or less than the predetermined reference length of time, the detection unit 134 detects the indication that the aerosol substrate 12 does not have the predetermined moisture content.

An example of the predetermined thermal profile and the monitored thermal profile (that is based on values obtained by the monitoring unit 132) according to the present example embodiment will now be described with reference to FIG. 5A.

In the example shown on FIG. 5A, the predetermined thermal profile defines four associations: t=0 s and 20° C.; t=6 s and 100° C.; t=9 s and 102° C.; and t=18 s and 230° C. Additionally, the predetermined thermal profile defines a reference length of time of 15.5 s, for the interval of 0 to 18 s defined by the first and last time instants in the predetermined thermal profile.

However, the number of association and the time instants/values defined in the predetermined thermal profile are exemplary, and the predetermined thermal profile may define any number of associations (e.g. one, three, ten, or more). Additionally, instead of a single reference length of time being defined for the entire interval that is spanned in the predetermined thermal profile, the predetermined thermal profile may instead define a respective predetermined reference length of time for one or more sub-intervals defined by pairs of time instants having an associated value in the predetermined thermal profile. For example the following reference lengths of time could be defined instead: a reference length of time of 7 seconds for the interval 0-9 s, a reference length of time of 2 seconds for the interval 6-9 s, and a reference length of time of 10 seconds for the interval 6-18 s.

In the example of FIG. 5A, the predetermined thermal profile includes information regarding a temperature change for the heating of the aerosol substrate from the predetermined value of 20° C. to the predetermined value of 90° C. over a predetermined length of time of 7 seconds. Additionally, the predetermined thermal profile shown on FIG. 5A also includes information regarding a temperature change for the heating of the aerosol substrate from the predetermined value of 20° C. to the predetermined value of 230° C. over a predetermined length of time of 18 seconds. In the second example, the first predetermined value (20° C.) is a predetermined initial temperature of the heating chamber 122, and the second predetermined value (230° C.) is a temperature of the device when an aerosol or vapor is generated from the aerosol substrate.

Although not shown on FIG. 5A, the predetermined threshold is set in this example to 5.5° C.

The rightmost column on FIG. 5A shows exemplary temperature values obtained by the monitoring unit 132 at intervals of 3 seconds from the beginning of the heating of the aerosol substrate 12.

Accordingly, in the example of FIG. 5A, the detection unit 134 detect an indication that the moisture content in the aerosol substrate 12 is different from the predetermined moisture content because:

- i) the obtained value is 135° C. at t=9 s, which differs from the predetermined value of 102° C. by more than the predetermined thermal threshold of 5° C., and/or
- ii) the monitored thermal profile changes from the value of 20° C. to the value of 230° C. (it is in fact a greater change, from 19° C. to 230° C.) in less than the reference length of time of 15.5 s (the difference between the time instants being only 15 seconds).

The detection unit 134 thus notifies the signaling unit 136, which generates the control signal for interrupting the operation of the aerosol generation device 100.

Although in the description above, the same threshold (of 5° C.) is used for all time instants, one or more of the predetermined values may have a respective predetermined thermal threshold. Additionally, lower and upper threshold values may be set differently for one or more of the predetermined values to define a range of allowable values (i.e. the threshold values define a minimum and maximum around the predetermined value).

An example of the thresholds defined in a predetermined thermal profile and a monitored thermal profile according to the modification will now be described with reference to FIG. 5B.

As shown on FIG. 5B, a threshold of 10° C. is set for the time instant t=0 s, with a minimum and maximum temperature values of 10° C. to 30° C. A minimum of 88° C. and a maximum of 93° C. are set for the time instant t=7 s (note this is equivalent to setting a threshold of −2° C. and +3° C. relative to the value of 90° C.). Similarly, minimums/maximums of 125° C./135° C. for the time instant t=12 s and 228° C./135° C. for the time instant t=17 s are set.

Accordingly, in the example of FIG. 5B, the detection unit 134 detect the indication if the value obtained by the monitoring unit 132 at t=7 is less than 88° C. or more than 93° C.

Thus, the detection may be more accurately made

It would be understood that, when a minimum and maximum value is set, the corresponding predetermined temperature value (20° C., 90° C., 130° C. and 230° C. shown in the second column) may be omitted, as the detection unit 134 determines whether the monitored value falls within the range defined by the minimum and maximum value.

In an example embodiment, the monitoring unit 132 is arranged for monitoring the thermal profile by obtaining temperature values that are indicative of a temperature associated with one of the aerosol generation device 100 and the aerosol substrate 12 at each of a plurality of time instants during the heating of the aerosol substrate 12.

The detection unit 134 is arranged for detecting the indication if at least one of the temperature values differs from a corresponding one of reference values by the predetermined thermal threshold or more, the reference values being determined based on the information of the temperature change.

More specifically, the detection unit 134 is arranged for determining, for one or more of the temperature values obtained by the monitoring unit 132, a respective reference value based on the information regarding the temperature change included in the predetermined threshold profile. The reference value may be determined for any time instants at which the monitoring unit 132 obtained a value, and for which the predetermined thermal profile does not define a predetermined value. The reference value may be determined, for example by using regression analysis or curve fitting.

Then, the detection unit 134 is arranged for comparing each value obtained by the monitoring unit 132 and the corresponding reference value that is determined. If the difference between the compared value is equal to or greater than the predetermined thermal threshold for any of the value obtained by the monitoring unit 132, the detection detects the indication that the moisture content in the aerosol substrate 12 is different from the predetermined moisture content.

The detection unit 134 may be arranged to only detect the indication when more than one of the values obtained in the monitored thermal profile differ from the corresponding reference values, as described above. This may reduce risks of incorrect detections. Additionally, or alternatively, predetermined thermal thresholds need not be set the same for all time instants, as described above.

Accordingly, the detection may be more accurately made whilst reducing the required resources to keep the predetermined profile(s).

An example of the present example embodiment will now be described, with reference to FIG. 5A.

In this example, the monitoring unit 132 obtains a value of 50° C. for the time instant t=3 s, 175° C. for the time instant t=12 s and 230° C. for the time instant t=15 s. As the predetermined thermal threshold does not define a predetermined value for these time instants, the detection unit 134 determines reference values for the time instants t=3 s, 12 s and 15 s.

The detection unit 134 determines the reference value using a linear regression of the predetermined values for the time instants t=0 s and t=6 s, namely the time instants before and after the time instant t=3 s for which a predetermined value is defined.

Accordingly, the detection unit 134 determines a reference value of: (3 s−0 s)/(6 s−0 s)*(98° C.−20° C.)+20° C.=59° C. Accordingly, the detection unit 134 detects the indication if the value of 50° C. in the monitored thermal profile differs from the reference value of 59° C. by more than the predetermined thermal threshold set of the time instant t=3 s.

For the time instants t=12 s and 15 s, the detection unit 134 is arranged for obtaining the reference values using a quadratic interpolation based on the predetermined values at the time instants t=6 s, 9 s and 18 s, which results in the equation T=148−14.778·t+1.074·t²(where t is the time instant and T is the reference value for the temperature). Accordingly, the detection unit 134 determines for the time instant t=12 s a reference value of: 148−14.77778*12+1.074074*12{circumflex over ( )}2=125.33° C. and for the time instant t=15 s a reference value of 168° C. The detection unit 134 then detects the indication if the value of 175° C. in the monitored thermal profile differs from the reference value of 125.33° C. by more than the predetermined thermal threshold set of the time instant t=12 s and/or if the value of 230° C. in the monitored thermal profile differs from the reference value of 168° C. by more than the predetermined thermal threshold set of the time instant t=15 s.

It would be understood that the detection unit 134 need not determine a reference value corresponding to each value obtained by the monitoring unit 132. Some of the values obtained by the monitoring unit 132 may not be compared to a reference value, although they may still be used to determine whether a change in the monitored thermal profile occurs substantially faster than in the predetermined thermal profile. For example, continuing with the example described above, the reference value for the time instant t=15 s need not be determined, as it is indicating that a change in the monitored thermal profile from 20° C. to 230° C. occurred significantly faster than in the predetermined thermal profile, which may on its own trigger the detection of the indication.

In an example embodiment, the monitoring unit 132 is arranged for obtaining, for each temperature value (i.e. for one or more temperature values), an associated measure of time between a time at which the heating of the aerosol substrate is initiated and a time at which the temperature indicated by the temperature value is reached.

In other words, when the monitoring unit 132 obtains a value of the temperature, the monitoring unit 132 is arranged for also obtaining a measure of the time elapsed since the heating of the aerosol substrate was initiated, and to associate this measure of time to the obtained value of the temperature.

As a first example, the monitoring unit 132 may be arranged for initiating a timer when the heating of the aerosol substrate 12 is initiated, and for obtaining an elapsed time indicated by the timer as the measure of time to be associated each time a temperature value is obtained.

As a second example, the monitoring unit 132 may be arranged for obtaining a temperature value at regular intervals (e.g. each 0.5 s) starting when the heating of the aerosol substrate 12 is initiated. In this case, the monitoring unit 132 obtains, for the first temperature value obtained when the heating of the aerosol substrate is initiated to be 0.

Then, for each subsequent temperature value, the monitoring unit 132 obtains the associated measure of time by incrementing the value by 0.5 s.

In the present example embodiment, the detection unit 134 is arranged for determining, for each temperature value, a point in the first predetermined length of time based on the associated measure of time, and for determining the reference value as the temperature specified by the information regarding the temperature change at the determined point.

For the exemplary predetermined thermal profile shown with a solid line on FIG. 3, the detection unit 134 may be arranged to determine, for a measure of time obtained by the monitoring unit 132, a temperature value on the predetermined thermal profile corresponding to the measure of time as the reference value.

For example, if the monitoring unit 132 obtains a temperature value of 105° C. and an associated measure of time of 8 seconds, the detection unit 134 determines the temperature value corresponding to 8 seconds on the predetermined thermal profile is 102° C., as the reference value. Although the example of FIG. 3 showing the predetermined thermal profile as a continuous function has been described, it should be understood that the detection unit 134 may instead use a predetermined thermal profile having a number of discrete values, for example as the associations described above.

In an example embodiment, the monitoring unit 132 is arranged for measuring a value indicative of an electrical power in the aerosol generation device 100 during the heating of the aerosol substrate.

For example, the monitoring unit 132 may be arranged for measuring, via one or more sensors, a value of an instantaneous power output by a power source, a value of an electrical current flowing through the aerosol generation device 100, a value of an electrical current provided to a specific component of the aerosol generation device (e.g. the heating arrangement 120).

In the present example embodiment, the monitoring unit 132 is arranged for monitoring the electrical energy profile by accumulating the value indicative of the electrical power during the heating of the aerosol substrate 12.

In other words, the monitoring unit 132 is arranged for summing the value indicative of the electrical power that is obtained at multiple time instants during the heating of the aerosol substrate, to obtain an accumulated power value (that is, a value indicating an amount of electrical power that has been generated or used from the instant at which the first value indicative of the electrical power is obtained, e.g. the start of the heating of the aerosol substrate 12).

In the present example embodiment, the predetermined electrical energy profile includes information indicative of a predetermined accumulated power value, and the detection unit 134 is arranged for detecting the indication if the accumulated value indicative of the electrical power differs from the predetermined accumulated power value, by a predetermined electrical energy threshold or more.

An example of electrical components of the aerosol generation device 100 according to the present example embodiment will be described, with reference to FIG. 6.

For brevity, description of the electrical components 120 to 150, will be omitted here, as these have already described in connection with FIG. 2.

In the example shown on FIG. 6, the aerosol generation device 100 includes a current measuring arrangement 160 for measuring an electrical current provided to the heating arrangement 120. The current measuring arrangement 160 comprises a shunt resistor 162 placed in series with the heating arrangement 120 (specifically, between a node B coupled to the positive terminal of the battery 142 and the controller 130, and the converter 128). The current measuring arrangement 160 also comprises a current measurement element 164 in parallel with the shunt resistor 162, the current measurement element 164 being arranged for detecting a value of the current flowing through the shunt resistor 162. Specifically, the current measurement element 164 is arranged for measuring a voltage across the terminals of the shunt resistor 162.

In the example shown on FIG. 6, the monitoring unit 132 is arranged for obtaining a value of the voltage measured across the shunt resistor 162 by the current measurement element 164, for deriving the value of the current flowing through the shunt resistor 162 based on the resistance value of the shunt resistor 162. Then, based on the value of the current flowing through the shunt resistor 162, the monitoring unit 132 is arranged for obtaining a value indicative of the electrical power that is provided to the heating arrangement 120. For example, the monitoring unit 132 may use a value of an equivalent resistance of the heating arrangement 120, or an equivalent resistance of the heater 124 that is predetermined, and to calculate the power provided to the heating arrangement 120 accordingly.

The monitoring unit 132 is arranged for accumulating the value indicative of the electrical power, during the heating of the aerosol substrate 12. For example, the monitoring unit 132 may obtain a first value at the beginning of the heating of the aerosol substrate 12, and to obtain a second value afterwards, during the heating of the aerosol substrate. The monitoring unit 132 may add the first and the second value as an accumulated power value indicating the electrical power provided to the heating arrangement 120 between the time instant when the first value is obtained and the time instant when the second value is obtained. Then, each time the monitoring unit 132 obtains a new value, the monitoring unit 132 adds the new value to the accumulated power value.

Still in the example shown on FIG. 6, the detection unit 134 obtains the accumulated power value from the monitoring unit 132. The detection unit 134 determines a corresponding predetermined accumulated power value based on the information included in the predetermined electrical energy profile, and compares the accumulated power value and the predetermined accumulated power value. If the compared values are different (e.g. different by a predetermined threshold or more), the detection unit 134 detect an indication that the moisture content in the aerosol substrate 12 is different from the predetermined moisture content.

Although a specific configuration of the aerosol generation device 100 with a current measuring arrangement has been described above, it would be understood that the present invention is not limited to this specific arrangement, and different configurations of the current measurement arrangement 160 and/or different placement of the current measuring arrangement 160 in the circuit shown on FIG. 6 are possible. For example, the current measurement arrangement (with the same or a different configuration) may be placed in series with the electrical power source 140, such that it may measure the current output from the electrical power source 140, or between the nodes labelled A and B on FIG. 6, such that it can measure the current provided to both the controller 130 and the heating arrangement 120. It would be understood that other locations for the current measuring arrangement 160 allowing the monitoring unit 132 to obtain a value indicative of the electrical power generated and/or used in the aerosol generation device 100 during the heating of the aerosol substrate 12 are possible.

Additionally, more than one current measurement arrangement (of the same or different configurations) may be provided in the aerosol generation device 100, and the present invention is not limited in this aspect. For example, a first arrangement may be provided for measuring a current output from a battery coupled to or in the device, and second arrangement may be provided for measuring a current provided to the heating arrangement 120.

In an example embodiment, the controller is arranged for controlling a temperature of the heating arrangement by controlling at least one switching element using a pulse width modulation.

For example, the controller 130 may be arranged to determine, based on a current temperature of the heating arrangement (which may be obtained via one or more temperature sensors such as the temperature sensor 126 described in connection with FIG. 1, or from a resistance of the heater 124) and a desired temperature of the heating arrangement, whether the temperature of the heating arrangement should be increased, decreased, or maintained at the current level. Based on the determination, the controller 130 can determine a duty cycle of the at least one switching element to increase, decrease or maintain the temperature of the heating arrangement, and generate one or more control signals using a pulse-width modulation scheme to control the respective state of the at least one switching element.

When the at least one switching element are controlled to be on, electrical current is allowed to flow through the heating arrangement, and when the at least one switching element are controlled to be off, the electrical current is prevented from flowing through the heating arrangement. Accordingly, when the at least one switching element are controlled to be off, no electrical energy is provided to the heating arrangement 120. Thus, the state of the at least one switching element can be used to determine the amount of electrical energy used during the heating of the aerosol substrate. In other words, the duty cycle of the control signal(s) used to control the switching element(s) is proportional to the electrical energy used to heat the aerosol substrate.

Each switching element may be of any known type of switching element (for example the types described in connection with FIG. 2 above) as the present invention is not limited in this aspect.

The controller may be arranged to control the temperature using any type of control such as those described in connection with FIG. 2 (e.g. PID, PI or P control loops) as the present invention is not limited in this aspect.

In the present example embodiment, the monitoring unit 132 is arranged for monitoring the electrical energy profile by calculating an amount of electrical energy used for the heating of the aerosol substrate based on lengths of time during which the pulse width modulation cause the at least one switching element to be on.

For example, the monitoring unit 132 may obtain the control signal(s) generated to control the state of the at least one switching element, and determine the amount of electrical energy that will be used by the heating arrangement during a part of the cycle where the at least one switching element is on. Then, an amount of electrical energy used during the heating of the aerosol substrate 12 (e.g. during the entire duration of the heating or part thereof) can be obtained by accumulating the determined amount of electrical energy during each cycle.

Accordingly, the controller in the present example embodiment can detect the indication that the moisture content of the aerosol substrate is different from a predetermined moisture content and generate the signal to interrupt the operation of the aerosol generation device, without requiring additional sensing/measuring components such as the current measuring arrangement 160.

An example of the aerosol generation device 100 according to the present example embodiment will now be described with reference to FIGS. 2 and 7.

As shown on FIG. 2, the heating arrangement 120 comprises a switching element 129, which in the present example is a MOSFET, although it would be understood that more than one switching element may be provided, as this may improve safety in case a switching element fails, and that the type of switching element described here is exemplary, as switching element(s) of various types can be provided instead.

In the present example embodiment, the controller 130 generates a pulse-width modulated control signal that is provided to the gate of the MOSFET 129. The control signal is controlled to vary between a high voltage level for causing the MOSFET 129 to allow current to flow between the drain and source of the MOSFET 129, and a low voltage level for causing the MOSFET 129 to interrupt current from flowing between the drain and the source of the MOSFET 129. For brevity, a detailed description of the control of the state of the MOSFET 129, which will be familiar to those skilled in the art, is omitted for the sake of clarity.

As the MOSFET 129 is connected in series with the heater 124 (specifically the drain and source terminals of the MOSFET 129 are connected in series with the heater 124), the controller 130 can control whether to allow current to flow through the heater 124 or not, by controlling the state of the MOSFET 129.

FIG. 7 shows an example of the duty cycle determined by the controller 130, which is used to generate the control signal to control the state of the MOSFET 129, and a temperature of the heater 124 during a heating of the aerosol substrate 12.

As shown on FIG. 7, in order to begin heating the aerosol substrate 12, the MOSFET 129 is controlled to be on, with a duty cycle of around 100%, in order to increase the temperature of the heater 124 to the desired temperature (e.g. in the range of 200-230° C.). As the temperature of the heater approaches around 150° C., the controller 130 determines the rate at which the temperature of the heater increases should be reduced, and thus reduces the duty cycle accordingly. As a result, as shown on FIG. 7, the duty cycle is lowered after 9 seconds, and the temperature of the heater increases at a lower rate. The controller 130 then regulates the temperature of the heater by controlling the duty cycle of the MOSFET 129 to be in the desired range allowing the aerosol or vapor to be generated.

Accordingly, if for example the moisture content of the aerosol substrate 12 is lower than the predetermined moisture content, less electrical energy will be needed to heat the aerosol substrate (e.g. if the content of water or another humectant is lower than the predetermined amount). This difference in electrical energy used to heat the aerosol substrate 12 can be detected as an indication that the moisture content in the aerosol substrate is lower than the predetermined moisture content.

Although the controller 130 has been described to be controlling the at least one switching element to control the temperature of the heating arrangement 120, alternatively, a second controller (not shown on FIG. 6) that is separate from the controller 130 may be arranged for controlling the temperature of the heating arrangement 120 instead. In these cases, the monitoring unit 132 may be arranged to obtain a value indicative of the temperature of the heating arrangement 120, a value indicative of a duty cycle determined for the control of the at least one switching element, or a value indicative of the control signal(s) generated by the second controller to control the state of the switching element(s).

Thus, the aerosol generation device 100 may comprise a second controller arranged for controlling a temperature of the heating arrangement by controlling at least one switching element using a pulse width modulation, and the monitoring unit may be arranged for monitoring the electrical energy profile by calculating an amount of electrical energy used for the heating of the aerosol substrate based on lengths of time during which the pulse width modulation used by the second controller to control the at least one switching element to be on.

Although the monitoring unit has been described to be arranged for calculating a cumulative length of time during which the at least one switching element is on, and to calculate the amount of electrical energy based on the cumulative length of time, alternatively, the monitoring unit may be arranged for calculating an average (arithmetic mean, weighted average, etc.) amount of electrical energy used for the heating of the aerosol substrate, and determine that the moisture content of the aerosol substrate is different than the predetermined moisture content if the calculated average amount is different from a predetermined average amount. Other combinations of values indicating the duty cycle of the control signal used to control the state of the switching element may be calculated instead of the average, such as a combination including a product of two or more of the values, a ratio of two or more of the values, etc.

It will be appreciated from the description above that certain example embodiments perform a method for controlling an aerosol generation device which comprises a receptacle for receiving a consumable comprising an aerosol substrate and a heating arrangement for heating the aerosol substrate.

Referring to FIG. 8, at step 802, the aerosol generation device monitors an observable indicative of a moisture content of the aerosol substrate during a heating of the aerosol substrate.

At step 804, the aerosol generation device detects, based on the monitored observable, an indication that the moisture content is different from a predetermined moisture content.

At step 806, the aerosol generation device generates, based on the detected indication, a control signal for interrupting an operation of the device.

Variations

Many modifications and variations can be made to the example embodiments described above.

In above-described example embodiments, the monitoring unit 132 monitors the observable from the start of a heating of the aerosol substrate 12. However, the monitoring unit 132 may also obtain a value of the observable (e.g. a moisture level, a temperature, an instantaneous electrical power or any other type of observable) before a consumable is received by the receptacle, or before a heating of the aerosol substrate is initiated. For example, the monitoring unit 132 may be arranged to obtain a value of the observable when a predetermined event occurs before heating of the aerosol substrate 12, such as the detection that a consumable is inserted or that the aerosol substrate should be heated.

This value of the observable may then be used as a reference value representative of the environment of the aerosol generation device 100. The detection unit 134 may obtain this environmental reference value and adapt the predetermined profile based on the environmental reference value, e.g. by increasing or reducing the value of the observable that is expected during the heating of the aerosol substrate, by changing a time instant associated with a value of an observable, etc.

For example, if the monitoring unit 132 detects that an ambient temperature is 30° C. whereas a predetermined thermal profile stores a value of 20° C. as an initial value and a value of 50° C. in association with a measure of time of 3 seconds after the start of the heating of the aerosol substrate 12, the detection unit 134 may increase the value of 50° C. (e.g. to 55° C.) and/or may decrease the associated measure of time (e.g. to 2.7 s), thereby taking into account that the environment is different from that indicated by the predetermined thermal profile. Similarly, a moisture level in the receptacle 110 before a consumable is received may be obtained as an environmental reference value, and/or an instantaneous power used in the device before heating the aerosol substrate may be obtained. It would be understood that the same obtention and use of an environmental reference value may be used for any other type of observable.

In above described example embodiments, the monitoring unit 132 obtains a value of the observable at one or more time instants during the heating of the aerosol substrate, and the detection unit 134 obtains each value of the observable from the monitoring unit 132. However, the monitoring unit 132 may alternatively be arranged to only provide values to the detection unit 134 that indicate the observable has changed by more than a specific amount, which may be absolute or relative to the previously output value (e.g. a change of at least 2% of the previously output value). Accordingly, the detection unit 134 may assume that the value of the observable has substantially not changed until a new value is output, thereby reducing the processing in the detection unit 134.

A person skilled in the art will, of course, recognize that modifications other than those described above can be made.

In particular, it would be understood that example embodiments described above may be combined.

In the foregoing description, example aspects are described with reference to several example embodiments. Accordingly, the specification should be regarded as illustrative, rather than restrictive. Similarly, the figures illustrated in the drawings, which highlight the functionality and advantages of the example embodiments, are presented for example purposes only. The architecture of the example embodiments is sufficiently flexible and configurable, such that it may be utilized in ways other than those shown in the accompanying figures.

Software embodiments of the examples presented herein may be provided as, a computer program, or software, such as one or more programs having instructions or sequences of instructions, included or stored in an article of manufacture such as a machine-accessible or machine-readable medium, an instruction store, or computer-readable storage device, each of which can be non-transitory, in one example embodiment. The program or instructions on the non-transitory machine-accessible medium, machine-readable medium, instruction store, or computer-readable storage device, may be used to program a computer system or other electronic device. The techniques described herein are not limited to any software configuration. They may find applicability in any computing or processing environment. The terms “computer-readable”, “machine-accessible medium”, “machine-readable medium”, “instruction store”, and “computer-readable storage device” used herein shall include any medium that is capable of storing, encoding, or transmitting instructions or a sequence of instructions for execution by the machine, computer, or computer processor and that causes the machine/computer/computer processor to perform any one of the methods described herein. Furthermore, it is common in the art to speak of software, in one form or another (e.g., program, procedure, process, application, module, unit, logic, and so on), as taking an action or causing a result. Such expressions are merely a shorthand way of stating that the execution of the software by a processing system causes the processor to perform an action to produce a result.

Some embodiments may also be implemented by the preparation of application-specific integrated circuits, field-programmable gate arrays, or by interconnecting an appropriate network of conventional component circuits.

Some embodiments include a computer program product. The computer program product may be a storage medium or media, instruction store(s), or storage device(s), having instructions stored thereon or therein which can be used to control, or cause, a computer or computer processor to perform any of the procedures of the example embodiments described herein. The storage medium/instruction store/storage device may include, by example and without limitation, an optical disc, a ROM, a RAM, an EPROM, an EEPROM, a DRAM, a VRAM, a flash memory, a flash card, a magnetic card, an optical card, nanosystems, a molecular memory integrated circuit, a RAID, remote data storage/archive/warehousing, and/or any other type of device suitable for storing instructions and/or data.

Stored on any one of the computer-readable medium or media, instruction store(s), or storage device(s), some implementations include software for controlling both the hardware of the aerosol generation device and for enabling the aerosol generation device or microprocessor to operate in accordance with the example embodiments described herein. Such software may include without limitation device drivers, operating systems, and user applications. Ultimately, such computer-readable media or storage device(s) further include software for performing example aspects of the invention, as described above.

Included in the programming and/or software of the aerosol generation device are software modules for implementing the procedures described herein. In some example embodiments herein, a module includes software, although in other example embodiments herein, a module includes hardware, or a combination of hardware and software.

While various example embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art(s) that various changes in form and detail can be made therein. Thus, the present invention should not be limited by any of the above described example embodiments, but should be defined only in accordance with the following claims and their equivalents.

Further, the purpose of the Abstract is to enable the Patent Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The Abstract is not intended to be limiting as to the scope of the example embodiments presented herein in any way. It is also to be understood that any procedures recited in the claims need not be performed in the order presented.

While this specification contains many specific embodiment details, these should not be construed as limitations on the scope of any inventions or of what may be claimed, but rather as descriptions of features specific to particular embodiments described herein. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.

In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various components in the embodiments described above should not be understood as requiring such separation in all embodiments.

Having now described some illustrative embodiments and embodiments, it is apparent that the foregoing is illustrative and not limiting, having been presented by way of example. In particular, although many of the examples presented herein involve specific combinations of apparatus or software elements, those elements may be combined in other ways to accomplish the same objectives. Acts, elements and features discussed only in connection with one embodiment are not intended to be excluded from a similar role in other embodiments or embodiments.

The apparatuses described herein may be embodied in other specific forms without departing from the characteristics thereof. Scope of the apparatuses described herein is thus indicated by the appended claims, rather than the foregoing description, and changes that come within the meaning and range of equivalence of the claims are embraced therein.

LIST OF REFERENCE SIGNS

- 10: consumable
- 12: aerosol substrate
- 100: aerosol generation device
- 110: receptacle
- 120: heating arrangement
- 122: heating chamber
- 124: heater (e.g. coil)
- 126: temperature sensor
- 128: converter
- 129: switching element(s) (e.g. MOSFET)
- 130: controller (e.g. MCU)
- 132: monitoring unit
- 134: detecting unit
- 136: signaling unit
- 140: electrical power source
- 142: battery
- 144: battery protection circuit
- 150: charging arrangement
- 152: connector (e.g. USB connector)
- 154: charging IC
- 160: current measuring arrangement
- 162: shunt resistor
- 164: current measurement element

Aerosol Generation Device

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