Aerosol-generating device and method with puff detection
A method of operating an aerosol-generating device is provided, the device including a power supply to supply power to generate the aerosol, and a controller, the method including: monitoring a parameter indicative of aerosol generation during operation of the device; and analysing the monitored parameter to identify a user puff defined by a puff start and end, the analysing including calculating first and second characteristics of the monitored parameter, and analysing the first and the second characteristics to determine the puff start and end, the parameter indicative of aerosol generation representing power supplied by the power supply, the first and the second characteristics respectively being a first and a second moving average value of the monitored parameter computed on a first and a second time window having a first and a second time window duration, the second time window duration being different from the first time window duration.
1 . An aerosol-generating device for generating an aerosol from an aerosol-forming substrate, the aerosol-generating device comprising;
a power supply configured to supply power to generate the aerosol; and
a controller configured to monitor a parameter indicative of aerosol generation during operation of the aerosol-generating device, and to analyse a first characteristic of the monitored parameter and a second characteristic of the monitored parameter to identify a user puff, the user puff defined by a puff start and a puff end,
wherein the parameter indicative of aerosol generation is a parameter representative of power supplied by the power supply,
wherein the first characteristic is a first moving average value of the monitored parameter computed on a first time window having a first time window duration,
wherein the second characteristic is a second moving average value of the monitored parameter computed on a second time window having a second time window duration, the second time window duration being different from the first time window duration, and
wherein the puff start is determined when the first moving average value and the second moving average value meet a predetermined relationship with respect to each other.
2 . The aerosol-generating device according to claim 1 , the aerosol-generating device being configured to perform a method comprising:
monitoring a parameter indicative of aerosol generation during operation of the aerosol-generating device; and
analysing the monitored parameter to identify a user puff, the user puff defined by a puff start and a puff end,
wherein the step of analysing the monitored parameter comprises steps of calculating a first characteristic of the monitored parameter, calculating a second characteristic of the monitored parameter, and analysing both the first characteristic and the second characteristic to determine the puff start and the puff end.
3 . The aerosol-generating device according to claim 1 , further comprising a heater, and wherein the monitored parameter is, or is representative of, power supplied to the heater during operation of the aerosol-generating device.
4 . The aerosol-generating device according to claim 1 , the aerosol-generating device being configured to receive an aerosol-generating article comprising the aerosol-forming substrate.
5 . The aerosol-generating device according to claim 3 , wherein the heater is an induction heater and the monitored parameter is representative of energy absorbed by a susceptor.
6 . The aerosol-generating device according to claim 3 , wherein the heater is a resistance heater and the monitored parameter is representative of energy supplied to the resistance heater.
7 . The aerosol-generating device according to claim 1 , wherein the aerosol-generating device is configured to analyse the monitored parameter to identify a plurality of user puffs performed during operation of the device, each of the plurality of user puffs having a puff start and a puff end determined by analysing the monitored parameter.
8 . The aerosol-generating device according to claim 1 , wherein the aerosol-generating device is configured to:
generate the aerosol during a usage session,
determine a start of the usage session, and
analyse the monitored parameter to identify the user puff performed during operation of the device.
9 . The aerosol-generating device according to claim 1 , wherein the puff start is determined when the first characteristic and the second characteristic satisfy one or more predetermined conditions.
10 . The aerosol-generating device according to claim 1 , wherein the puff end is determined when the first characteristic and the second characteristic satisfy one or more predetermined conditions.
11 . The aerosol-generating device according to claim 1 , wherein the first time window duration is shorter than the second time window duration and the puff start is determined when the first moving average increases with respect to the second moving average and reaches a puff start value in which the first moving average equals the second moving average plus a first predetermined puff start constant.
12 . The aerosol-generating device according to claim 11 , wherein the puff end is determined when the first moving average decreases with respect to the second moving average, after the detection of the puff start, and reaches the puff end value in which the first moving average is greater than the second moving average minus a first predetermined puff end constant, and the second moving average is lesser than the value of the second moving average at puff start plus a second predetermined puff end constant.
13 . The aerosol-generating device according to claim 1 , wherein the aerosol-generating device is configured to:
analyse the monitored parameter during the user puff to calculate a puff volume, the puff volume being a volume of aerosol generated during the user puff, and
use the puff volume as a parameter for controlling operation of the device.
14 . The aerosol-generating device according to claim 13 , wherein the aerosol-generating device is configured to:
generate the aerosol during a usage session,
determine a start of the usage session,
monitor the parameter indicative of aerosol generation during the usage session, and
use the puff volume as a parameter for determining the end of the usage session.
15 . The aerosol-generating device according to claim 1 , wherein the aerosol-generating device is configured to:
analyse the monitored parameter to identify a plurality of user puffs performed during operation of the device, each of the plurality of user puffs having a puff start and a puff end determined by analysing the monitored parameter,
analyse the monitored parameter during each of the plurality of identified user puffs to calculate a puff volume for each of the plurality of user puffs,
determine a cumulative puff volume of aerosol generated during each of the plurality of identified user puffs, and
use the cumulative puff volume as a parameter for controlling operation of the device.
16 . The aerosol-generating device according to claim 15 , wherein the aerosol-generating device is configured to:
generate the aerosol during a usage session,
determine a start of the usage session,
monitor the parameter indicative of aerosol generation during the usage session, and
use the cumulative puff volume as a parameter for determining the end of the usage session.
17 . The aerosol-generating device according to claim 14 , wherein the controller ends the usage session if a time elapsed from the start of the usage session reaches a predetermined threshold.
18 . The aerosol-generating device according to claim 16 , wherein the controller ends the usage session if a time elapsed from the start of the usage session reaches a predetermined threshold.
19 . The aerosol-generating device according to claim 14 , wherein the controller ends the usage session if the puff volume generated from the start of the usage session reaches a predetermined threshold.