EP4229235B1

EP4229235B1 - Garment care device with valve system

Info

Publication number: EP4229235B1
Application number: EP21836346.3A
Authority: EP
Inventors: Lee POH CHOON; Mehendale ADITYA; Henricus Antonius Verspaget; Jia Jiunn KHNG; Zhibin Ye
Original assignee: Koninklijke Philips NV
Current assignee: Versuni Holding BV
Priority date: 2020-12-04
Filing date: 2021-12-01
Publication date: 2024-02-14
Anticipated expiration: 2041-12-01
Also published as: EP4008832A1; EP4229235A1; WO2022117688A1; CN116670355A

Description

FIELD OF THE INVENTION

The invention relates to a garment care device, and in particular controlling steam delivery from the garment care device.
The invention may be used in the field of garment care.

BACKGROUND OF THE INVENTION

Garment care devices, such as garment steamers and steam irons, are commonly used for de-wrinkling fabrics and garments. Wrinkles in such fabrics and garments can vary in terms of their responsiveness to de-wrinkling treatment by such a garment care device.
For example, a particularly stubborn wrinkle can require repeated ironing strokes over the relatively small area in which the wrinkle is located.
Garment care devices are known which have a so-called "steam boost" feature. The steam boost corresponds to an increase in the steam rate and is used, for example, for assisting in removing particularly stubborn wrinkles. In some cases, the steam boost can expedite removal of such wrinkles.
However, the user is required to manually trigger the steam boost during operation of the garment care device in order to increase the steam rate, and this can make the device less convenient to use.
EP 3 447 187 A1 discloses a garment care device comprising a sensor for generating an output signal characterizing a movement of the garment care device, and a control unit coupled to the sensor. The control unit is adapted to identify and compare characteristics of the output signal to characteristics of a predefined displacement pattern, and to adjust at least one operating parameter of the garment care device based on the result of the comparison between characteristics of the output signal and characteristics of the predefined displacement pattern.
DE 20 2006 001242 U1 discloses a garment care system comprising a steam generator with a steam outlet.

OBJECT AND SUMMARY OF THE INVENTION

It is an object of the invention to propose a garment care device that avoids or mitigates the above-mentioned problems.
The invention is defined by the independent claims. The dependent claims define advantageous embodiments.
To this end, the garment care device according to the invention comprises

a steam generator for generating steam, the steam generator comprising a steam outlet,
a soleplate comprising steam vents being in fluid communication with the steam generator,
a valve system arranged between the steam outlet and the steam vents for regulating the flow of steam between the steam outlet and the steam vents,
a sensor for measuring the velocity of the garment care device,
a processing unit for controlling the valve system as follows:
1. a) if the velocity is in a first range of velocity, the processing unit is adapted to control the valve system so that the flow of steam is in a first range of steam rate,
2. b) if the velocity is in a second range of velocity, the processing unit is adapted to control the valve system so that the flow of steam is in a second range of steam rate, wherein the first range of velocity and the second range of velocity do not overlap with each other and are both strictly larger than 0, and wherein the first range of steam rate and the second range of steam rate do not overlap with each other and are both strictly larger than 0.

In this manner, steam is delivered at different steam rates according to the velocity of the garment care device. By the steam rate being responsive to this velocity, manual adjustment of the steam rate may be obviated. Thus, user convenience of the garment care device is improved.
In a non-limiting example, the second range of velocity is higher than the first range of velocity, and the second range of steam rate is higher than the first range of steam rate. In this case, a higher velocity movement of the garment care device can indicate that more steam is required to treat the fabric, e.g. to remove a stubborn wrinkle.
]] For instance, the first range of velocity is [15;135] cm/second, and the first range of steam rate is [30;99] g/minute. In this example, the second range of velocity is ] 135;200] cm/second, and the second range of steam rate is ]99; 170] g/minute.
In a non-limiting example, the garment care device may have more than one operating mode for example Normal mode and Max mode. It should be understood that the first range of steam rate and the second range of steam rate could have different range of values when the garment care device is in a given operating mode.
For example:

when the garment care device is in Normal mode, the first range of steam rate is [30;99] g/minute and the second range of steam rate is ]99; 170] g/min.
when the garment care device is in Max mode, the first range of steam rate is [100; 160] g/minute and the second range of steam rate is ]160; 170] g/min.

Preferably, the first range of velocity comprises a first sub-range of velocity and a second sub-range of velocity, which sub-ranges do not overlap with each other, and wherein:

if the velocity is in the first sub-range of velocity, the processing unit is adapted to control the valve system so that the flow of steam is in a first sub-range of steam rate,
if the velocity is in the second sub-range of velocity, the processing unit is adapted to control the valve system so that the flow of steam is in a second sub-range of steam rate.

This provides further control over the steam rate in accordance with the velocity of the garment care device.
For example, the first sub-range of velocity is [15;70] cm/second, and the first sub-range of steam rate is [30;50] g/minute. In this example, the second sub-range of velocity is ]70;135] cm/second, and the second sub-range of steam rate is ]50;99] g/minute.
Likewise, it should be understood that the first sub-range of steam rate and the second sub-range of velocity as described in the above paragraphs can also have different ranges of values when the garment care device is in different operating mode.
Preferably, the valve system comprises a first controllable valve and a second controllable valve fluidly arranged in parallel, the first controllable valve and the second controllable valve each having both an open state to let steam pass therethrough and a closed state to block the steam.
Such a valve system enables control over the steam rate in a particularly convenient manner, since the steam rate can be adjusted via the four selectable open/closed permutations of the first and second controllable valves.
Preferably, the first controllable valve and the second controllable valve have internal orifices with different diameters.
Such a design enables the valve system to deliver steam with various steam rates according to the respective range, or in some examples sub-range, of velocity fulfilled by the measured velocity of the garment care device.
Alternatively, the first controllable valve and the second controllable valve have internal orifices with the same diameter.
Preferably, the sensor is adapted to measure the velocity in a horizontal plane.
If the soleplate is not horizontal, a velocity determination algorithm can process one or more horizontal components of the movement. In some non-limiting examples, the measured velocity is neglected or the velocity processing is halted when the soleplate is not horizontal.
The sensor is preferably adapted to measure the velocity along a longitudinal axis of the soleplate.
The velocity along the longitudinal axis of the soleplate may correspond to the velocity in a direction of interest upon which steam rate control is usefully based.
The horizontal plane comprises an x-direction and a y-direction, and the velocity is preferably in the x-direction, or in the y-direction, or the velocity is a vector combination of a velocity component in the x-direction and a velocity component in the y-direction.
In an embodiment, the garment care device comprises:

a handle,
a presence sensor arranged in the handle for detecting whether the user is holding the handle,

This assists to improve the safety of the garment care device. Wastage of steam and energy is also minimised or prevented because the steam supply is halted when the user is detected by the presence sensor to not be holding the handle, for instance in order to adjust a garment or to change a steamed garment for a garment which is yet to be steamed.
Preferably, the presence sensor is a capacitive sensor. Such a capacitive sensor may be particularly suitable for detecting holding or touching of the handle by the user.
Preferably, the sensor is an acceleration sensor.
When the sensor comprises, or is defined by an acceleration sensor, e.g. an accelerometer, the measured acceleration is converted to the velocity. Such a conversion is implementable with, for example, a central processing unit which is integral to or separate from the sensor. In some examples, at least part of the computing implementing the conversion can take place in the processing unit.
The processing unit is preferably further configured to control the temperature of the soleplate and/or the steam generator based on the velocity measured by the sensor.
Controlling the temperature of the steam generator provides a further way of controlling the steam rate, in addition to the control provided via the valve system. Controlling the temperature of the soleplate in this manner means that the heat to which the garment is exposed is based on the velocity with which the garment care device is moved. This can assist to provide enhanced de-wrinkling conditions.
Preferably, the garment care device comprises a hand unit, the hand unit comprising the soleplate and the sensor.
According to the invention, there is provided a method of controlling steam generation in a garment care device comprising

a steam generator for generating steam, the steam generator comprising a steam outlet,
a soleplate comprising steam vents being in fluid communication with the steam generator,
a valve system arranged between the steam outlet and the steam vents for regulating the flow of steam between the steam outlet and the steam vents,
a sensor for measuring the velocity of the garment care device,
the method comprising the step of controlling the valve system as follows:
1. a) if the velocity is in a first range of velocity, controlling the valve system so that the flow of steam is in a first range of steam rate,
2. b) if the velocity is in a second range of velocity, controlling the valve system so that the flow of steam is in a second range of steam rate, wherein the first range of velocity and the second range of velocity do not overlap with each other and are both strictly larger than 0, and wherein the first range of steam rate and the second range of steam rate do not overlap with each other and are both strictly larger than 0.

Detailed explanations and other aspects of the invention will be given below.

BRIEF DESCRIPTION OF THE DRAWINGS

Particular aspects of the invention will now be explained with reference to the embodiments described hereinafter and considered in connection with the accompanying drawings, in which identical parts or sub-steps are designated in the same manner:

Fig. 1 depicts a garment care device according to an example,
Fig.2 depicts part of an exemplary garment care device, which part includes a steam generator and a valve system,
Fig.3 depicts a hand unit of an exemplary garment care device,
Fig.4 provides a diagram of processing of speed and direction of movement of at least part of an exemplary garment care device,
Fig.5 provides a flowchart of control logic for controlling an exemplary garment care device, and
Fig.6 schematically depicts a two dimensional coordinate transformation for evaluating velocity in a direction of interest.

DETAILED DESCRIPTION OF THE INVENTION

Provided is a garment care device comprising a steam generator for generating steam. The steam generator comprises a steam outlet. A soleplate comprises steam vents which are in fluid communication with the steam generator. A valve system is arranged between the steam outlet and the steam vents for regulating the flow of steam between the steam outlet and the steam vents. A sensor measures a parameter relating to movement of at least part of the garment care device, and a processing unit controls the valve system and/or the steam generator such as to control delivery of steam based on the measured parameter.
Fig.1 depicts a garment care device 100 according to an example. The garment care device 100 comprises a water tank 102 for containing water. A steam generator 104 for generating steam is in fluid communication with the water tank 102.
The steam generator 104 comprises a steam outlet 105. Steam exits the steam generator 104 via the steam outlet 105.
As shown in Fig.1, water is pumped from the water tank 102 to the steam generator 104 by a pump 106. Steam is generated in the steam generator 104 from the water pumped thereto by the pump 106. To this end, the steam generator 104 includes a heating element (not visible), such as a resistive heating element, arranged to heat the water therein to generate the steam.
The garment care device 100 further comprises a soleplate 108. The soleplate 108 has, or may be regarded as defining, a surface for treating fabrics.
As shown in Fig.1, the soleplate 108 delimits a plurality of steam vents 110. The steam vents 110 are fluidly communicable with the steam generator 104, as will be explained in more detail herein below. Fluid communication between the steam generator 104 and the steam vents 110 permits the steam generated in the steam generator 104 to be supplied to a fabric adjacent, e.g. contacting, the soleplate 108.
The steam vents 110 may, for example, be arranged in such a way as to distribute the steam to different portions of the fabric.
Whilst Fig.1 shows a garment care device 100 having three steam vents, this is merely for the purpose of illustration, and any suitable alternative number of steam vents 110 may be considered, such as two, four, five, six, seven, eight, nine, ten, eleven, twelve, or more.
In the non-limiting example shown in Fig.1, the garment care device 100 comprises a deaerator arrangement 109 between the pump 106 and the steam generator 104. The deaerator arrangement 109 comprises a check valve 109A for preventing backflow from the steam generator 104 towards the water tank 102, and a valve 109B for regulating flow of water around a loop back to the water tank 102, as shown.
The exemplary garment care device 100 depicted in Fig.1 comprises a base 112 and a hand unit 114. The base 112 comprises the water tank 102, the steam generator 104, and the pump 106. The hand unit 114 comprises the soleplate 108, as shown.
A hose cord 116 includes a steam tube (not visible) for carrying steam from the steam generator 104 towards the steam vents 110. The hose cord 116 is preferably flexible in order to facilitate movement of the hand unit 114 whilst maintaining supply of steam from the steam generator 104 to the steam vents 110.
Moreover, the garment care device 100 need not comprise the base 112 and hand unit 114 components shown in Fig.1. In other examples, the components of the garment care device 100 are included in the hand unit 114, and no separate base is required.
More generally, the garment care device 100 comprises a valve system V arranged between the steam outlet 105 and the steam vents 110. The valve system V regulates the flow of steam between the steam outlet 105 and the steam vents 110.
The valve system V preferably comprises a first controllable valve V1 and a second controllable valve V2 fluidly arranged in parallel. The first controllable valve V1 and the second controllable valve V2 each have both an open state to permit the steam to pass therethrough and a closed state to block the steam.
Such a valve system V enables control over the steam rate in a particularly convenient manner, since the steam rate can be adjusted via the four selectable open/closed permutations of the first and second controllable valves V1, V2. This exemplary valve system V will be discussed in more detail herein below with reference to Fig.2.
At this point it is noted that the valve system V is included in the base 112 in the example shown in Fig.1. However, this should not be regarded as being limiting. At least part of the valve system V, e.g. the first controllable valve V1 and the second controllable valve V2, can be positioned elsewhere in the garment care device 100.
More generally, the garment care device 100 comprises a sensor 120 for measuring the velocity of the garment care device 100, in other words the velocity of at least part of the garment care device 100, e.g. the hand unit 114.
The sensor 120 can include any suitable motion sensor for measuring the velocity of the at least part of the garment care device 100. For example, the sensor 120 comprises an accelerometer, such as a micro electromechanical system (MEMS) accelerometer.
When the sensor 120 comprises, or is defined by an accelerometer, e.g. a MEMS accelerometer, the measured acceleration is converted to the velocity. Such a conversion is implementable with, for example, a central processing unit which is integral to or separate from the sensor 120. In some examples, at least part of the computing for the conversion can take place in the processing unit 122. The use of such an accelerometer to measure the velocity of the at least part of the garment care device 100, e.g. the hand unit 114 comprising the soleplate 108, will be described in more detail herein below with reference to Figs.4 to 8 and 10.
The processing unit 122 included in the garment care device 100 is configured to control the valve system V as follows:

a) if the velocity is in a first range of velocity, the processing unit 122 is adapted to control the valve system V so that the flow of steam is in a first range of steam rate,
b) if the velocity is in a second range of velocity, the processing unit 122 is adapted to control the valve system V so that the flow of steam is in a second range of steam rate.

The first range of velocity and the second range of velocity do not overlap with each other and are both strictly larger than 0, and the first range of steam rate and the second range of steam rate do not overlap with each other and are both strictly larger than 0.
In this manner, the steam is delivered at different steam rates according to the velocity of the at least part of the garment care device 100.
In a non-limiting example, the second range of velocity is higher than the first range of velocity, and the second range of steam rate is higher than the first range of steam rate. In this case, a higher velocity movement of the garment care device 100 can indicate that more steam is required to treat the fabric, e.g. to remove a stubborn wrinkle.
]] For instance, the first range of velocity is [15;135] cm/second, and the first range of steam rate is [30;99] g/minute. In this example, the second range of velocity is ] 135;200] cm/second, and the second range of steam rate is ]99;170] g/minute.
In a non-limiting example, the garment care device may have more than one operating mode for example Normal mode and Max mode. It should be understood that the first range of steam rate and the second range of steam rate could have different range of values when the garment care device is in a given operating mode.
For example:

when the garment care device is in Normal mode, the first range of steam rate is [30;99] g/minute and the second range of steam rate is ]99;170] g/min.
when the garment care device is in Max mode, the first range of steam rate is [100; 160] g/minute and the second range of steam rate is ]160;170] g/min.

The first range of velocity preferably comprises a first sub-range of velocity and a second sub-range of velocity, which sub-ranges do not overlap with each other, and

if the velocity is in the first sub-range of velocity, the processing unit 122 is adapted to control the valve system V so that the flow of steam is in a first sub-range of steam rate,
if the velocity is in the second sub-range of velocity, the processing unit 122 is adapted to control the valve system V so that the flow of steam is in a second sub-range of steam rate.

This provides further control over the steam rate in accordance with the velocity of the at least part of the garment care device 100.
For example, the first sub-range of velocity is [15;70] cm/second, and the first sub-range of steam rate is [30;50] g/minute. In this example, the second sub-range of velocity is ]70;135] cm/second, and the second sub-range of steam rate is ]50;99] g/minute.
Controlling the flow of steam by the processing unit 122 sending control signals to the valve system V provides an effective way of regulating the steam rate. In particular, the valve system V may cause the steam delivery of the garment care device 100 to respond relatively rapidly to the velocity of the at least part of the garment care device 100.
The processing unit 122 can be implemented in numerous ways, with software and/or hardware, to perform the various required functions. A processor is one example of a processing unit 122 which employs one or more microprocessors that can be programmed using software (e.g. microcode) to perform the functions. The processing unit 122 may, however, be implemented with or without employing a processor, and also may be implemented as a combination of dedicated hardware to perform some functions and a processor, e.g. one or more programmed microprocessors and associated circuitry, to perform other functions.
Examples of controller components that may be employed in various embodiments of the present disclosure include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASICs), and field-programmable gate arrays (FPGAs).
In some examples, the processing unit 122 is associated with one or more storage media such as volatile and non-volatile computer memory such as RAM, PROM, EPROM, and EEPROM. The storage media can be encoded with one or more programs that, when executed on one or more processors and/or controllers, perform the required functions. Various storage media may be fixed within the processing unit 122 or may be transportable, such that the one or more programs stored thereon can be loaded into the processing unit 122.
In the exemplary garment care device 100 shown in Fig.1, the processing unit 122 is included in the base 112, although other suitable locations for the processing unit 122, such as in the hand unit 114, can be considered.
When the processing unit 122 is included in the base 112, the sensor 120 can be connected with the processing unit 122 in any suitable manner, e.g. via wiring (not visible) included in the hose cord 116.
Preferably, the garment care device 100 comprises a handle 124 for grasping by the user in order to assist the user to move the soleplate 108 relative to the fabric to be treated. The handle 124 may thus be included in the hand unit 114.
The garment care device 100 preferably comprises, in addition to the sensor 120, a presence sensor 126 arranged in the handle 124 for detecting whether the user is holding the handle 124. In this case, the processing unit 122 is adapted, if the presence sensor 126 detects that the user is not holding the handle 124, to control the valve system V so that the flow of steam is 0 g/minute.
This assists to improve the safety of the garment care device 100. Wastage of steam and energy is also minimised or prevented because the steam supply is halted when the user is detected by the presence sensor 126 to not be holding the handle 124, for instance in order to adjust a garment or to change a steamed garment for a garment which is yet to be steamed.
The presence sensor 126 may have any suitable design or may be of any suitable type that is capable of detecting whether or not the user is holding the handle 124. For example, the presence sensor 126 comprises, or is defined by, a touch sensor configured to detect holding of the handle 124 by the user.
Preferably, the presence sensor 126 comprises or is a capacitive sensor. Such a capacitive sensor may be particularly suitable for detecting holding or touching of the handle 124 by the user.
The presence sensor 126 is preferably provided in, on or proximal to the handle 124, as shown in Fig.1. The presence sensor 126 is, for example, arranged on an underside of the handle 124 such that the holding is detected when the user's hand and/or digits reach around to the underside when grasping the handle 124. Alternatively, the presence sensor 126 is arranged such as to detect contact being made with the upper side of the handle 124.
In examples in which the valve system V comprises the first controllable valve V1 and the second controllable valve V2, the processing unit 122 is adapted to control both the first controllable valve V1 and the second controllable valve V2 to be closed in order to limit the flow of steam to 0 g/minute.

The control over the steam rate based on the velocity can be regarded as an "auto mode" of the garment care device 100. The presence sensor 126, e.g. capacitive sensor, can be regarded as enabling steam on/off control. The combination of the inputs from the sensor 120 and the presence sensor 126 can, for example, be used to enhance steam stop performance in the auto mode. An example of this is provided in the following Table 1.

Table 1:

System	State of presence sensor 126	Control Usage
Pressurized steam generator ironing system with valve system V, e.g. comprising the first and second controllable valves V1, V2	True (hand touch on handle)	During auto mode, enables the steam control; steam output will depend on the velocity measured by the sensor 120
	False (hand away from handle)	During auto mode, stops the steam/steam control; steam output will stop immediately regardless of the velocity measured by the sensor 120

Fig.2 depicts the steam generator 104 and the valve system V of an exemplary garment care device 100. In this non-limiting example, the valve system V comprises, or can be regarded as being defined by, the first controllable valve V1 and the second controllable valve V2 fluidly arranged in parallel. The first controllable valve V1 and the second controllable valve V2 each have both an open state to permit the steam to pass therethrough and a closed state to block the steam, as briefly described above in relation to Fig.1.
The arrow in Fig.2 points in the downstream direction towards the steam vents 110.
The first and second controllable valves V1, V2, e.g. electro-valves, such as Combi AC electro-valves, are, for example, built into a common valve housing VH, and are thereby provided in a discrete component of the garment care device 100.
The first controllable valve V1 has a first internal orifice, and the second controllable valve V2 has a second internal orifice. In a first example, the diameter of the first internal orifice is different from the diameter of the second internal orifice.
Such a design enables the valve system V to conveniently deliver steam with various steam rates according to the respective range, or in some examples sub-range, of velocity fulfilled by the measured velocity of the garment care device 100.

For example, the diameter of the first internal orifice is 3 mm, and the diameter of the second internal orifice is 2 mm. The various steam rates which are deliverable in such an example are presented in the following Table 2.

Table 2:

		First controllable valve V1
		3 mm diameter orifice
		On (Open)	Off (Close)
Second controllable valve V2 2 mm diameter orifice	On (Open)	"High Steam"	"Low Steam"
		Normal mode: 100 g/min	Normal mode: 45 g/min
		Max mode: 170 g/min	Max mode: 145 g/min
	Off (Close)	"Medium Steam"	No Steam (0 g/min)
		Normal mode: 90 g/min
		Max mode: 160 g/min

A as shown in above table 2, in a non-limiting example, when the device is operated in Normal mode, the "Low Steam" and the "Medium Steam" correspond to values in the first sub-range of steam rate and the second sub-range of steam rate described previously, respectively, when the velocity is in the first sub-range of velocity and the second sub-range of velocity, respectively.
As well as controlling the configuration of the first and second controllable valves V1, V2, the steam rate can also be set according to, for example, the selected temperature of the steam generator 104.
A higher steam generator 104 temperature can be set for the Max mode, and a lower steam generator 104 temperature can be set for the Normal mode. Such Max and Normal modes can be user-selectable, e.g. via a user interface included in the garment care device 100.
More generally, the processing unit 122 is, in at least some examples, configured to control the heating element included in the steam generator 104. Such control over the heating element by the processing unit 122 is, for instance, in response to movement, e.g. velocity, measured by the sensor 120 of the at least part of the garment care device 100 and/or in response to a user selection entered via a user interface included in the garment care device 100.
Alternatively, the first controllable valve V1 and the second controllable valve V2 each have internal orifices with the same diameter. For example, the diameter of both the first and second internal orifices is 2 mm or 3 mm.
This makes for a simpler steam rate control system, albeit with fewer selectable steam rates than the scenario in which the first internal orifice of the first controllable valve V1 is different from the diameter of the second internal orifice of the second controllable valve V2.
Fig.3 provides a perspective view of a hand unit 114 of a garment care device 100. In this non-limiting example, the sensor 120 and the presence sensor 126 are assembled into the handle 124 of the hand unit 114.
More generally, by locating the sensor 120 and/or the presence sensor 126, if the presence sensor 126 is included in the garment care device 100, in the handle 126, the risk of damaging such components, for example by heat from the steam generator 104, or as a result of water leaking from the water tank 102, may be reduced.
A printed circuit board assembly 128 comprising the sensor 120, e.g. MEMS accelerometer, is mounted in the handle 124 within a first housing part 130.
The printed circuit board assembly 128 further comprises electronics included in the presence sensor 126. In this example, the presence sensor 126 comprises a capacitive sensor. A capacitive flex 132 of the capacitive sensor is built inside the top cover 137 of the handle 124. The capacitive flex 132 is disposed on top of a second housing part 134 which, together with the first housing part 130, encloses the printed circuit board assembly 128. An elastomeric or rubber material 136 is also included to fill up the air gap which would otherwise be present within the top cover 137 of the handle 124.
Fig.4 provides a diagram of processing of speed and direction of movement of the at least part of the garment care device 100. In this non-limiting example, the sensor 120 comprises, or is defined by, an accelerometer, and in particular a MEMS accelerometer. In this non-limiting example, the raw data from the MEMS accelerometer is processed via firmware.
The raw data from the MEMS accelerometer in this example, as represented in Fig.4 by the arrow 146, is 3-axis digital linear accelerometer output. The firmware retrieves the newly acquired acceleration raw data from the MEMS accelerometer, typically with a sampling interval of 10 milliseconds.
Box 148 in Fig.4 represents smoothing of the raw data via a moving average of a number of samples, e.g. 8 samples. The moving average data is used as input data for further processing. In particular, the moving average data is transferred, as represented by arrow 150, to an algorithm for speed detection and ironing stroke direction detection in box 152.
The arrow 154 represents the speed detection output. The arrow 156 represents the ironing stroke direction detection output.
The algorithm for detecting the velocity will now be explained. The following should be regarded as a non-limiting example, and it is emphasised that the velocity may be determined from the data gathered by the sensor 120 in any suitable manner.
In this non-limiting example, the moving average data is discrete-time-integrated to velocity, which in turn is further integrated to position. Discrete numerical integration works simply as: $New velocity = previous velocity + acceleration * time step$
where the time step corresponds to the take-time at which the firmware retrieves and processes the newly acquired data, typically 10 milliseconds.
The accelerometer may report values as milli g, where g is the earth's gravitational acceleration ~9.8 m/s². The numerical values for velocity and position in the firmware have units of cm/second and cm. Such use of non-S.I. units in this case facilitates the use of integer arithmetic.
The firmware can estimate the approximate tilt of the hand unit 114 based on the acceleration seen in the z-direction. This is used to disable the integrator, in other words to stop the counting and reset its values, when the data indicate that the hand unit 114 is not horizontal. This assists to prevent relatively large integrated values accumulating due to the relatively large acceleration due to gravity and tilt. Whereas the acceleration due to the earth's gravity is ~9.8 m/s², the typical acceleration due to the user's ironing strokes while vigorously ironing is merely ~2 m/s². Thus, any portion of gravitational acceleration that cannot be filtered out, either with tilt detection or with filtering, can be detrimental to accurate velocity estimation.
Hence, more generally, the sensor is preferably adapted to measure the velocity in a horizontal plane.
If the soleplate 108 is not horizontal, the velocity algorithm can work on one or more horizontal components of the movement. In some non-limiting examples, the measured velocity is neglected or the velocity processing is halted when the soleplate 108 is not horizontal.
The approach may, for example, employ one or more additional decision trees to reduce or eliminate the effect of gravitational acceleration.

Returning to the exemplary velocity algorithm, the firmware can model the accelerometer/tracker as a unit mass, with a "spring" that applies a restoring force to "track" or "follow" the accelerometer's position. The Eigen frequency of this mass-spring system (2πf = √(k/m), where f is the Eigen frequency, m is the mass, and k is the spring constant) decides the sluggishness with which the mass follows the accelerometer (in model space). The sloppier the spring, the less aggressive the tracking. Some advantages and disadvantages associated with selection of the model spring are summarised in the following Table 3.

Table 3:

Choice	Effect	Resulting advantage	Resulting disadvantage
Sloppy spring	Lower Eigen frequency	Faithful reproduction of actual velocity, even for gentle ironing strokes; smaller return overshoot in the event of a single-direction stroke	Needs longer to recover from a tilt error; more error due to centripetal acceleration from arc-shaped strokes
Stiff spring	Higher Eigen frequency	Quicker return to zero after tilt events, better immunity against integrator drift	Inability to correctly estimate velocity of gentle ironing strokes, larger return overshoot

In a particular non-limiting example, the Eigen frequency is selected to be 0.1 Hz. This can provide a reasonable trade-off between the advantages and disadvantages summarised in Table 3 in respect of typical movements made when carrying out ironing. It may be possible to fine tune this parameter, e.g. to reach a different Eigen frequency.
A damper can also be included in the model. Such a damper assists to prevent the model's own dynamics from influencing the estimated velocity. For example, a damping ratio of 0.707 can assist to prevent peaking at the resonant frequency of the tracker without slowing the tracker significantly:
r = 1.414 * √(m.k); [here 2ζ = 2 * 0.707 = 1.414, where ζ is the damping ratio]
This way of calculation of the damper, r, preserves the damping ratio independently of the chosen Eigen frequency (which may change depending on the selected stiffness/sloppiness of the spring).

Non-limiting examples of results from the algorithm for velocity measurement are provided in the following Table 4.

Table 4:

Parameter	Value Type	Setting Range for High/Medium/Low Set Threshold	Examples
Velocity	Di screte integer; range value: [-32768, +32767]	High Speed:	Firmware checks for set threshold of High Speed only.
		velocity in the second range of velocity: >135 cm/second to 200 cm/second;	Delivers high steam when ironing speed is greater than set threshold of High Speed; or velocity is in the second range of velocity.
		Medium Speed: velocity in the second sub-range of velocity: >70 cm/second to 135 cm/second;	Delivers low steam when ironing speed is lower than set threshold of High Speed; or velocity is in the first sub-range of velocity.
			Firmware checks for set threshold of High Speed, and Low Speed.
		Low Speed: velocity in the first sub-range of 15 cm/second to 70 cm/second	Delivers high steam when ironing speed is greater than set threshold of High Speed; or velocity is in the second range of velocity.
			Delivers low steam when ironing speed is lower than set threshold of Low Speed; or velocity is in the first sub-range of velocity.
			Other case: delivers normal steam when in between High Speed and Low Speed; or velocity is in the second sub-range of velocity.

The processing unit 122 is configured to adjust the steam rate based on the measured velocity, as previously described. A non-limiting example of this is provided in the following Table 5, which details applications of the velocity detection in terms of regulating the steam rate.

Table 5:

Garment care device	Status of Set-Threshold Checking	Control Usage	Steam output / Pump flow rate	Set Temperatur e
Pressurized steam generator ironing system (with valve system V, e.g. comprising the first and second controllable valves V1, V2)	Ironing speed faster than set threshold, e.g. 135 cm/s; or in the second range of velocity, e.g. >135 cm/second to 200 cm/second	Trigger higher steam output via valve system V, e.g. V1 and V2 opened.	100 g/minute; or in the second range of steam rate, e.g. >100 g/minute to 160 g/minute	145°C to 160°C
				When continuous steam set to 164°C
	Ironing speed lower than set threshold, e.g. 135 cm/second; or in the first range of velocity, e.g. 15 cm/second to 135 cm/second	Low steam output via valve system V control, e.g. V2 (e.g. 2 mm diameter orifice) opened only; V1 is closed.	70 g/minute; or in the first range of steam rate, e.g. 30 g/minute to 100 g/minute	When continuous steam set to 164°C

In the case of the pressurized steam generator ironing system, it is reiterated that, as well as using the valve system V comprising the first controllable valve V1 and the second controllable valve V2, the steam rate can be controlled to increase or decrease via the set temperature of the steam generator 104.
Fig.5 provides a flowchart of at least part of an exemplary method of controlling steam generation in the garment care device 100. Box 200 of the control logic depicted in Fig.5 corresponds to the sensor 120, e.g. the MEMS accelerometer described above, detecting the movement of the garment care device 100, and processing the data to provide an estimate of the velocity.
Box 202 corresponds to the presence sensor 126, e.g. capacitive sensor, detecting whether the user is holding the handle 124. Box 202 can include processing of raw data gathered from, for instance, the capacitive sensor.
The decision box 204 corresponds to whether or not the user is holding or touching the handle 124, as detected by the presence sensor 126. If the answer to decision box 204 is "N" (i.e. no), the steam output is stopped in box 206. If the answer to decision box 204 is "Y" (i.e. yes), the steam rate is controlled in box 206 according to the measured/estimated velocity, as previously described.

The following Table 6 provides an overview of control logic of steam output based on different states according to another non-limiting example.

Table 6:

Iron movement	Detected Motion State	Detected Velocity	Holding/touching State	Steam Output
Static	REST	< 5 cm/second	No touch	No steam
Static	REST	< 5 cm/second	Touched	No steam
Moving	MEDIUM_STROKE	< 135 cm/second (less than set threshold of High Speed)	No touch	No steam
		< 135 cm/second (less than set threshold of High Speed)	Touched	Low steam (70 g/minute)
		> 135 cm/second (greater than set threshold of High Speed)	No touch	No steam
		> 135 cm/second (greater than set threshold of High Speed)	Touched	High steam (100 g/minute)

In this example, the control logic operates as follows:

1. The user moves the iron.
2. Firmware processes, in box 200, raw data from the sensor 120, e.g. MEMS accelerometer, using a function to check for the motion detection state. The Steam Output state is either REST in which case no steam is produced, SHORT_STROKE in which case the steam rate is set to Low Steam, MEDIUM_STROKE in which case the steam rate is set to Normal Steam, and LONG_STROKE in which case the steam rate is set to High Steam.
3. Firmware processes, in box 202, raw data from the presence sensor 126, e.g. capacitive sensor, using a function to check holding or touching of the handle 124. If the handle 124 is detected as being held/touched, the control logic will continue flow down to subsequent processing of steam generator 104 control and/or steam rate output control in box 206. If no touch is detected, the detected motion state will be reset to REST so that no steam is produced, and flow down to subsequent processing in box 206.
4. Firmware processes, in box 206, boiler control and steam rate output control based on the result of 3.

When a transition in the detected motion state occurs, a delay is preferably added, e.g. in the order of 1 to 2 seconds, in which the current state is held. This assists to prevent overly frequent switching between the set threshold values.
More generally, the velocity is preferably in the x-direction, or in the y-direction, or the velocity is a vector combination of a velocity component in the x-direction and a velocity component in the y-direction.
The absolute velocity can, in at least some examples, be used as the velocity. The absolute velocity is, for example, calculable as a Pythagorean sum.
Components in the x-direction and y-direction can be calculated by integrating and filtering the raw values from the sensor 120, e.g. the accelerometer.
Combining the components in the x-direction and the y-direction can render it possible, depending on the use case, to rotate the coordinate axis to obtain any combination of x and y.
The same principle can also be used for combining with the component in the z-direction, although the movement of the hand unit 114 will tend to be in the horizontal plane, such that calculations can be simplified by aligning the z-axis of the sensor to the z-axis of the soleplate, and then neglecting it for the velocity estimation calculations, as previously described.
The estimated velocity is along the x- (v_x) and y-directions (v_y), as reported by the sensor 120, e.g. the accelerometer. Any direction on the x-y plane can be assigned as the direction of interest, e.g. for the purpose of steam rate control, by a two dimensional coordinate transformation.
The evaluation of the velocity along the direction of interest (v_i), and directions orthogonal to the direction of interest (v_o) is then: $v_{i} = v_{x} \cos (α) + v_{y} \sin (α)$
$v_{o} = - v_{x} \sin (α) + v_{y} \cos (α)$
Where α is the angle between v_i and v_x, as shown in Fig.6.
The sine and cosine coefficients can be evaluated up front, for example during compile time, as opposed to run time, to carry out this coordinate transformation.
Adaptive thresholding rules can subsequently be applied to the calculated direction of interest, instead of the pure x- or y-directions.

Some cases of this coordinate-transformation are listed in the following Table 7.

Table 7:

α = 0°	"normal" front-direction trigger	sin(α) = 0	v_i = v_x
	"normal" front-direction trigger	cos(α) = 1	v_o = v_y
α = 90°	"sideways" left-direction trigger	sin(α) = 1	v_i = v_y
	"sideways" left-direction trigger	cos(α) = 0	v_o = -v_x
α = 45°	Diagonal right-front	sin(α) = 0.7	v_i = 0.7v_x + 0.7v_y
	Diagonal right-front	cos(α) = 0.7	v₀ = -0.7v_x+ 0.7v_y
α = 135°	Diagonal left-front	sin(α) = 0.7	v_i = -0.7v_x + 0.7v_y
	Diagonal left-front	cos(α) = -0.7	v_o = -0.7v_x - 0.7v_y
α = 180°	"normal" back-direction trigger	sin(α) = 0	v_i = -v_x
	"normal" back-direction trigger	cos(α) = -1	v_o = -v_y
...			etc.

The above embodiments as described are only illustrative, and not intended to limit the technique approaches of the present invention. Although the present invention is described in details referring to the preferable embodiments, those skilled in the art will understand that the technique approaches of the present invention can be modified or equally displaced without departing from the protective scope of the claims of the present invention. In particular, although the invention has been described based on a garment care device, it can be applied to any household device having a steam generator, such as a steaming vacuum cleaner. 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. Any reference signs in the claims should not be construed as limiting the scope.

Claims

A garment care device (100) comprising:
- a steam generator (104) for generating steam, the steam generator comprising a steam outlet (105),

- a soleplate (108) comprising steam vents (110) being in fluid communication with said steam generator,

- a valve system (V) arranged between said steam outlet and said steam vents for regulating the flow of steam between said steam outlet and said steam vents,

- a sensor (120) for measuring the velocity of the garment care device,

- a processing unit (122), characterized in that the processing unit is configured to control said valve system as follows:
a) if the velocity is in a first range of velocity, said processing unit is adapted to control the valve system so that the flow of steam is in a first range of steam rate,

b) if the velocity is in a second range of velocity, said processing unit is adapted to control the valve system so that the flow of steam is in a second range of steam rate, wherein said first range of velocity and said second range of velocity do not overlap with each other and are both strictly larger than 0, and wherein said first range of steam rate and said second range of steam rate do not overlap with each other and are both strictly larger than 0.
Garment care device (100) as claimed in claim 1, wherein said first range of velocity comprises a first sub-range of velocity and a second sub-range of velocity, which sub-ranges do not overlap with each other, and wherein:
- if the velocity is in the first sub-range of velocity, said processing unit (122) is adapted to control the valve system (V) so that the flow of steam is in a first sub-range of steam rate,

- if the velocity is in the second sub-range of velocity, said processing unit (122) is adapted to control the valve system (V) so that the flow of steam is in a second sub-range of steam rate.
Garment care device (100) as claimed in any one of the preceding claims, wherein said valve system (V) comprises a first controllable valve (V1) and a second controllable valve (V2) fluidly arranged in parallel, said first controllable valve and said second controllable valve each having both an open state to let steam pass therethrough and a closed state to block the steam.
Garment care device (100) as claimed in claim 3, wherein said first controllable valve (V1) and said second controllable valve (V2) have internal orifices with different diameters.
Garment care device (100) as claimed in claim 4, wherein:
- only said first controllable valve (V1) is in open state if the velocity is in the first range of velocity, or

- only said second controllable valve (V2) is in open state if the velocity is in the first range of velocity, or

- both said first controllable valve (V1) and said second controllable valve (V2) are in open state if the velocity is in the second range of velocity.
Garment care device (100) as claimed in claim 3, wherein said first controllable valve (V1) and said second controllable valve (V2) have internal orifices with the same diameter.
Garment care device (100) as claimed in any one of the preceding claims, wherein said sensor (120) is adapted to measure the velocity in a horizontal plane.
Garment care device (100) as claimed in claim 7, wherein said sensor (120) is adapted to measure the velocity along a longitudinal axis of said soleplate (108).
Garment care device (100) as claimed in claim 7 or claim 8, wherein said horizontal plane comprises an x-direction and a y-direction, said velocity being in the x-direction, or in the y-direction, or the velocity is a vector combination of a velocity component in the x-direction and a velocity component in the y-direction.
Garment care device (100) as claimed in any one of the preceding claims, wherein said garment care device comprises:
- a handle (124),

- a presence sensor (126) arranged in said handle for detecting whether said user is holding said handle,
said processing unit (122) being adapted, if the presence sensor detects that said user is not holding said handle, to control the valve system (V) so that the flow of steam is 0 g/minute.
Garment care device (100) as claimed in claim 10, wherein said presence sensor (126) is a capacitive sensor.
Garment care device (100) as claimed in any one of the preceding claims, wherein said sensor (120) is an acceleration sensor.
Garment care device (100) as claimed in any one of the preceding claims, wherein the processing unit (122) is configured to control the temperature of the soleplate (108) and/or the steam generator (104) based on the velocity measured by the sensor (120).
Garment care device (100) as claimed in any one of the preceding claims, wherein the garment care device comprises a hand unit (114), the hand unit comprising the soleplate (108) and the sensor (120).
A method of controlling steam generation in a garment care device (100) comprising
- a steam generator (104) for generating steam, the steam generator comprising a steam outlet (105),

- a soleplate (108) comprising steam vents (110) being in fluid communication with said steam generator,

- a valve system (V) arranged between said steam outlet and said steam vents for regulating the flow of steam between said steam outlet and said steam vents,

- a sensor (120) for measuring the velocity of the garment care device, characterized in that said method comprises the step of controlling said valve system as follows:
a) if the velocity is in a first range of velocity, controlling the valve system so that the flow of steam is in a first range of steam rate,

b) if the velocity is in a second range of velocity, controlling the valve system so that the flow of steam is in a second range of steam rate, wherein said first range of velocity and said second range of velocity do not overlap with each other and are both strictly larger than 0, and wherein said first range of steam rate and said second range of steam rate do not overlap with each other and are both strictly larger than 0.