FIELD OF THE INVENTION
[0001] The subject-matter of the present disclosure relates to personal care appliances
and indicating when an operational head of a personal care appliance requires replacing,
plus transitory, or non-transitory, computer-readable media.
BACKGROUND OF THE INVENTION
[0002] Personal care appliances, such as hair cutting devices, often include a cutter. The
cutter, when first installed to the personal care appliance, is sharp and cuts or
shaves hair well. However, over time, the cutter or shaving device becomes blunter
and requires replacing.
[0003] Generating a replacing signal for a user can be difficult because different users
have different hair types. For example, one user may have a dense beard with thick
hair. Another use may have a sparse beard with finer hair. The former will blunt the
cutter more than the latter.
[0004] It is an aim of the subject-matter of the present disclosure to improve on the prior
art.
SUMMARY OF THE INVENTION
[0005] According to a first aspect of the present invention, there is provided a computer-implemented
method of indicating when an operational head of a personal care appliance needs to
be replaced. The computer-implemented method comprises monitoring, using a sensor
of the personal care appliance, an operational parameter associated with operating
the operational head, constructing a distribution of values of the operational parameter,
monitoring changes in the distribution over time, and sending a signal that the operational
head needs replacing based on the changes in the distribution.
[0006] In an example, changes in the distribution over time include a change in a value
of the operational parameter associated with an nth percentile.
[0007] In an example, sending the signal that the operational head needs replacing based
on the changes in the distribution comprises comparing the value of the operational
parameter associated with the nth percentile to a signal threshold, sending the signal
that the operational head needs replacing when value of the operational parameter
associated with the nth percentile is greater than the signal threshold, not sending
the signal that the operational head needs replacing when operational parameter associated
with the nth percentile is less than or equal to the signal threshold.
[0008] In an example, the constructing the distribution of values of the operational parameter
comprises continually updating the distribution over time.
[0009] In an example, the constructing a distribution of values of the operational parameter
comprises comparing individually sensed instances of the operational parameter to
an operational parameter threshold, discarding any instances below the operational
parameter threshold, retaining any instances at or above the operational parameter
threshold, and using the retained instances of the operational parameter as values
for the distribution.
[0010] In an example, the method further comprises obtaining a standard deviation of instances
of the operational parameter, and setting the operational parameter threshold as the
standard deviation multiplied by a factor greater than 1, for example 6.
[0011] In an example, sending the signal that the operational head needs replacing based
on the changes in the distribution comprises sending the signal to a display device
to display a notification to the user to replace the operational head.
[0012] In an example, the display device is on the personal care appliance. In another example,
the display device is a remote display device.
[0013] In an example monitoring the operational parameter sensed by a sensor of the personal
care appliance comprises measuring, using the sensor, real time values of the operational
parameter, and subtracting the real time values of the operational parameter from
a free-running value of the operational parameter.
[0014] In an example, subtracting the real time values of the operational parameter from
the free-running value of the operational parameter comprises monitoring a real time
free-running value of the operational parameter, and subtracting the real time value
of the operational parameter from the real time free-running value of the operational
parameter over time.
[0015] In an example monitoring the real time free-running value of the operational parameter
comprises determining the real time free-running value of the operational parameter
by using a low-pass filter on the real time values of the operational parameter to
discard values above a filter threshold, and/or calculating a moving minimum value
from the real time values of the operational parameter, and/or calculating a moving
nth percentile value from the real time values of the operational parameter.
[0016] In an example, the personal care appliance is a hair cutting device and the operational
head is a cutter, wherein optionally the hair cutting device is a trimmer.
[0017] According to a second aspect of the invention, there is provided a transitory, or
non-transitory, computer-readable medium, having instructions stored thereon, that
when executed by one or more processors, cause the one or more processors to perform
the aforementioned computer-implemented method.
[0018] According to a third aspect of the invention, there is provided a personal care appliance,
comprising a handle, an attachment for attaching an operational head to the handle,
a sensor coupled to the handle, and a controller including a processor and storage,
wherein the storage includes instructions that, when executed by the processor, cause
the processor to perform the aforementioned computer-implemented method.
[0019] These and other aspects of the present invention will be apparent from and elucidated
with reference to the embodiment(s) described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The embodiments of the present inventions may be best understood with reference to
the accompanying figures, in which:
Fig. 1 shows a block diagram of a personal care appliance according to one or more
embodiments;
Fig. 2 shows a series of parameter values captured over time for respective new and
worn operational heads of the personal care appliance;
Fig. 3 shows a graph for use in determining real time values of an operational parameter
minus real time free running values of the operational parameter, according to one
or more embodiments;
Fig. 4A shows a time series plot of the real time values when using the personal care
appliance;
Fig. 4B shows the time series plot from Fig. 4A of real time values above a threshold;
Fig. 4C shows the time series plot from Fig. 4B after values below the threshold have
been discarded and only values greater than or equal to the threshold have been retained;
Fig. 5 shows the distribution of operational parameter values using the time series
plot from Fig. 4C; and
Fig. 6 shows a flow chart summarising a computer-implemented method of indicating
when an operational head of a personal care appliance needs to be replaced.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0021] At least some of the example embodiments described herein may be constructed, partially
or wholly, using dedicated special-purpose hardware. Terms such as 'component', 'module'
or 'unit' used herein may include, but are not limited to, a hardware device, such
as circuitry in the form of discrete or integrated components, a Field Programmable
Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC), which performs
certain tasks or provides the associated functionality. In some embodiments, the described
elements may be configured to reside on a tangible, persistent, addressable storage
medium and may be configured to execute on one or more processors. These functional
elements may in some embodiments include, by way of example, components, such as software
components, object-oriented software components, class components and task components,
processes, functions, attributes, procedures, subroutines, segments of program code,
drivers, firmware, microcode, circuitry, data, databases, data structures, tables,
arrays, and variables. Although the example embodiments have been described with reference
to the components, modules and units discussed herein, such functional elements may
be combined into fewer elements or separated into additional elements. Various combinations
of optional features have been described herein, and it will be appreciated that described
features may be combined in any suitable combination. In particular, the features
of any one example embodiment may be combined with features of any other embodiment,
as appropriate, except where such combinations are mutually exclusive. Throughout
this specification, the term "comprising" or "comprises" means including the component(s)
specified but not to the exclusion of the presence of others.
[0022] With reference to Fig. 1, a personal care appliance 100 according to one or more
embodiments includes a handle 102, an attachment 104, an operational head 106, a power
source 108, a controller 110, a motor 112, a sensor 114, and a display 116.
[0023] The personal care appliance 100 may be a hair removal appliance such as a trimmer
or a shaver, for example. The operational head 106 is a device that performs an operation,
e.g. hair removal. The operational head may be a cutting element. The cutting element
includes a guard and a cutter. The cutter and the guard each comprise teeth which
cut hair therebetween to when the cutter moves reciprocally over the guard.
[0024] The attachment 104 attaches the operational head 106 to the handle 102.
[0025] The power source 108 may be a battery, e.g. a secondary, or rechargeable, battery.
[0026] The controller 110 may include storage and one or more processors. The storage includes
electronic data in the form of instructions. The instructions, when executed by the
one or more processors, may cause the one or more processors to perform the computer-implemented
methods described herein. In this way, the storage may be non-transitory computer
readable media. The instructions may also be provided as transitory computer-readable
media when provided as a download to be stored on the storage.
[0027] The motor 112 may consume energy from the power source 108 when operating. This energy
may be sensed by the sensor 114. The sensor sensed an operational parameter associated
with operating the operational head. The operational parameter being current or power.
The sensor 114 may be coupled to the handle 102.
[0028] The display 116 may be mounted to an exterior surface of the handle 102 and communicatively
linked to the controller so as to display indications generated by the controller.
[0029] With reference to Fig. 2, both graphs show operational parameter values cycling between
values associated with cutting hair and values associated with a free-running motor.
The values of a free-running motor are associated with the troughs 202 and the values
of cutting hair are associated with the peaks 204. Also shown on each graph is an
average value line 206, a value plus 10% of the average value 208, and a value minus
10% of the average value 210. The upper figure is associated with a brand-new cutter.
The lower figure is associated with a worn cutter. It can be seen that the amplitude
between values associated with cutting hair and values associated with a free-running
motor is larger for the worn cutting element, and therefore the +10% lines 208, 210,
are farther apart.
[0030] Therefore, it can be seen that the operational parameter values can be used for determining
when the operational head needs replacing since there are differences between worn
and brand-new cutters.
[0031] Embodiments provide computer-implemented method of indicating when an operational
head 106 of a personal care appliance 100 needs to be replaced. The computer-implemented
method comprises: monitoring, using a sensor of the personal care appliance, an operational
parameter associated with operating the operational head; constructing a distribution
of values of the operational parameter; monitor changes in the distribution over time;
and sending a signal that the operational head needs replacing based on the changes
in the distribution.
[0032] With reference to Fig. 3, the monitoring the operational parameter sensed by a sensor
of the personal care appliance may comprise measuring, using the sensor, real time
values 304 of the operational parameter; and subtracting the real time values of the
operational parameter from a free-running value 302 of the operational parameter.
[0033] Subtracting the real time values of the operational parameter from the free-running
value of the operational parameter comprises: monitoring a real time free-running
value 302 of the operational parameter; and subtracting the real time value 304 of
the operational parameter from the real time free-running value of the operational
parameter over time. The result of the subtraction is the real time values 306. Using
this method to obtain values of the operational parameter is more accurate because
the free-running values are in real-time, i.e. they are continually updated rather
than, for example, the free-running values being assumed to be constant.
[0034] It is possible to obtain the real-time free running value 302 in various ways. For
instance, it is possible to determine the real time free-running value of the operational
parameter by using a low-pass filter on the real time values 304 of the operational
parameter to discard values above a threshold. The threshold may be set at what is
known to be a free-running value of a motor for example. Another way is to calculate
a moving minimum value from the real time values of the operational parameter. The
moving minimum uses a time window which moves with time. A minimum real time value
304 in the window is obtained and is used as the real-time free running value 302.
Another way is to calculate a moving n
th percentile value from the real time values of the operational parameter. The n
th percentile may be a 1st, 2nd or even a 3rd percentile, for example, although other
percentiles may be used too. Another way is to obtain a standard deviation of instances
of the operational parameter and calculate the threshold as a multiplication of the
standard deviation by a factor greater than 1, for example 6.
[0035] With reference to Fig. 4A, a time series plot 402 of values of the operational parameter
is obtained for a use of the personal care appliance by monitoring the operational
parameter.
[0036] With reference to Fig. 4B, the time series plot 404 is shown where the values are
compared to an operational parameter threshold 406. Any values of the operational
parameter below the operational parameter threshold 406 are discarded. Any values
of the operational parameter greater than or equal to the threshold are retained.
[0037] With reference to Fig. 4C, the time series plot 408 is condensed. In other words,
the time series plot only shows values that are at or above the threshold with no
gaps between them.
[0038] With reference to Fig. 5, the retained instances of the operational parameter are
used as values for the distribution 502. To construct the distribution, a number of
instances, N, of each current value is obtained. The number of instances, N, are arranged
in descending order. A distribution is fitted to the ordered instances.
[0039] The distribution is updated, or changed, with each use. More specifically, the number
of instances, N, or values of the operational parameter, are continually updated,
or aggregated, with each use such that the number of instances changes over time.
[0040] A value of the operational parameter associated with the n
th percentile is determined. The n
th percentile 504 may be, for example, 75
th percentile, 90
th percentile, 99
th percentile, or 99.9
th percentile. Other values may also be used. As the cutter becomes more worn, the more
current will be drawn when using it. Therefore, the distribution will change such
that the value of the operational parameter associated with the n
th percentile will shift. The shift will be an increase in the value of the operational
parameter.
[0041] In this way, the change in the distribution that is monitored over time may include
a change in a value of the operational parameter associated with the nth percentile.
[0042] In order to send the signal that the operational head needs replacing based on the
changes in the distribution comprises: comparing the value of the operational parameter
associated with the n
th percentile to a signal threshold; sending the signal that the operational head needs
replacing when value of the operational parameter associated with the nth percentile
is greater than the signal threshold; and not sending the signal that the operational
head needs replacing when operational parameter associated with the nth percentile
is less than or equal to the signal threshold.
[0043] The distribution may be continually updated over time. This may be done in real time
or after each use.
[0044] The signal may be a signal to a display device to display a notification to the user
to replace the operational head.
[0045] With reference to Fig. 1, the display device 116 may be on the personal care appliance
100. In other embodiments, the display device 116 may be a remote display device.
[0046] With reference to Fig. 6, a computer-implemented method of indicating when an operational
head 106 of a personal care appliance 100 needs to be replaced, the computer-implemented
method comprising: monitoring 600, using a sensor 114 of the personal care appliance,
an operational parameter associated with operating the operational head; constructing
602 a distribution of values of the operational parameter; monitor 604 changes in
the distribution over time; and sending 606 a signal that the operational head needs
replacing based on the changes in the distribution.
[0047] While the invention has been illustrated and described in detail in the drawings
and foregoing description, such illustration and description are to be considered
illustrative or exemplary and not restrictive; the invention is not limited to the
disclosed embodiments.
[0048] Other variations to the disclosed embodiments can be understood and effected by those
skilled in the art in practicing the claimed invention, from a study of the drawings,
the disclosure, and the appended claims. In the claims, the word "comprising" does
not exclude other elements or steps, and the indefinite article "a" or "an" does not
exclude a plurality. A single processor or other unit may fulfil the functions of
several items recited in the claims. The mere fact that certain measures are recited
in mutually different dependent claims does not indicate that a combination of these
measured cannot be used to advantage. Any reference signs in the claims should not
be construed as limiting the scope.
1. A computer-implemented method of indicating when an operational head (106) of a personal
care appliance (100) needs to be replaced, the computer-implemented method comprising:
monitoring (600), using a sensor (114) of the personal care appliance, an operational
parameter associated with operating the operational head;
constructing (602) a distribution of values of the operational parameter;
monitor (604) changes in the distribution over time; and
sending (606) a signal that the operational head needs replacing based on the changes
in the distribution.
2. The computer-implemented method of Claim 1, wherein changes in the distribution over
time include a change in a value of the operational parameter associated with an nth percentile.
3. The computer-implemented method of Claim 2, wherein the sending the signal that the
operational head needs replacing based on the changes in the distribution comprises:
comparing the value of the operational parameter associated with the nth percentile to a signal threshold;
sending the signal that the operational head needs replacing when value of the operational
parameter associated with the nth percentile is greater than the signal threshold; and
not sending the signal that the operational head needs replacing when operational
parameter associated with the nth percentile is less than or equal to the signal threshold.
4. The computer-implemented method of any preceding claim, wherein the constructing the
distribution of values of the operational parameter comprises:
continually updating the distribution over time.
5. The computer-implemented method of any preceding claim, wherein the constructing a
distribution of values of the operational parameter comprises:
comparing individually sensed instances of the operational parameter to an operational
parameter threshold;
discarding any instances below the operational parameter threshold;
retaining any instances at or above the operational parameter threshold; and
using the retained instances of the operational parameter as values for the distribution.
6. The computer-implemented method of Claim 5, further comprising:
obtaining a standard deviation of instances of the operational parameter,
wherein the operational parameter threshold is the standard deviation multiplied by
a factor greater than 1, for example 6.
7. The computer-implemented method of any preceding claim, wherein the sending the signal
that the operational head needs replacing based on the changes in the distribution
comprises:
sending the signal to a display device (116) to display a notification to the user
to replace the operational head.
8. The computer-implemented method of Claim 7, wherein the display device is on the personal
care appliance.
9. The computer-implemented method of Claim 7, wherein the display device is a remote
display device.
10. The computer-implemented method of any preceding claim, wherein the monitoring the
operational parameter sensed by a sensor of the personal care appliance may comprises:
measuring, using the sensor, real time values (304) of the operational parameter;
and
subtracting the real time values of the operational parameter from a free-running
value (302) of the operational parameter.
11. The computer-implemented method of Claim 10, wherein the subtracting the real time
values of the operational parameter from the free-running value of the operational
parameter comprises:
monitoring a real time free-running value of the operational parameter; and
subtracting the real time value of the operational parameter from the real time free-running
value of the operational parameter over time.
12. The computer-implemented method of Claim 11, wherein the monitoring the real time
free-running value of the operational parameter comprises determining the real time
free-running value of the operational parameter by:
using a low-pass filter on the real time values of the operational parameter to discard
values above a filter threshold; and/or
calculating a moving minimum value from the real time values of the operational parameter;
and/or
calculating a moving nth percentile value from the real time values of the operational
parameter.
13. The computer-implemented method of any preceding claim, wherein the personal care
appliance is a hair cutting device and the operational head is a cutter, wherein optionally
the hair cutting device is a trimmer.
14. A transitory, or non-transitory, computer-readable medium, having instructions stored
thereon, that when executed by one or more processors, cause the one or more processors
to perform the computer-implemented method of any preceding claim.
15. A personal care appliance, comprising:
a handle (102);
an attachment (104) for attaching an operational head (106) to the handle;
a sensor (114) coupled to the handle; and
a controller (110) including a processor and storage, wherein the storage includes
instructions that, when executed by the processor, cause the processor to perform
the computer-implemented method of any of Claims 1 to 13.