GB2625147A

GB2625147A - A cleaning appliance

Info

Publication number: GB2625147A
Application number: GB2218528.4A
Authority: GB
Inventors: Hristov Popov Emil; John Bateman Christopher; John Dennis Spillman Andrew
Original assignee: Dyson Technology Ltd
Current assignee: Dyson Technology Ltd
Priority date: 2022-12-09
Filing date: 2022-12-09
Publication date: 2024-06-12
Also published as: WO2024121717A1; GB202218528D0

Abstract

The present invention relates to a cleaning appliance 2 and particularly to a cleaning appliance comprising a main body 6 and a cleaner head 4, the cleaning appliance comprising an improved system for controlling and communicating with a cleaner head. In particular, the present invention provides a cleaning appliance wherein the main body is configured to supply power to the cleaner head via a plurality of conductors, and wherein: the main body comprises a first controller configured to modulate the supply of power to the cleaner head, and the cleaner head comprises a second controller configured to detect a modulation in the supply of power and, responsive to the modulation, control a component of the cleaner head. The first controller may be configured to modulate the power supply by: pausing the supply of power, adjusting the pulse-width modulation (PWM) frequency of the supply of power and/ or adjusting a PWM pulse width of the supply of power.

Description

I

A CLEANING APPLIANCE

Field of the Invention

The present invention relates to a cleaning appliance and particularly, although not exclusively, to a cleaning appliance comprising a main body and a cleaner head, the cleaning appliance comprising an improved system for controlling and/or communicating with a cleaner head.

Background

Certain types of vacuum cleaner appliances comprise a main body which is connectable to a cleaner head. For example, they may be a "stick-vac" type vacuum cleaner comprising a handheld vacuum cleaner which is attached to an elongate, rigid wand and which is fluidly connected to a cleaner head provided at the end of the wand. In such vacuum cleaners, a cleaner head may be connected directly to the main body or, in some arrangements, may be connected to the main body via a rigid wand. An example of such a vacuum cleaner may be found in US 8347455 B2 or US 9301665 B2.

In some examples of such vacuum cleaners, power may be delivered from the main body to the cleaner head, for example to power a motor which is present in the cleaner head. However, it can be difficult to control additional components present within the cleaner head. In particular, it is difficult and expensive to implement a communications channel between the main body and the cleaner head which can be used to control any additional components.

The present invention has been devised in light of the above considerations.

Summary of the Invention

According to a first aspect of the present invention, there is provided a cleaning appliance, for example a vacuum cleaner, comprising a main body and a cleaner head, wherein the main body is configured to supply power to the cleaner head via a plurality of conductors, wherein: the main body comprises a first controller configured to modulate the supply of power to the cleaner head, and the cleaner head comprises a second controller configured to detect a modulation in the supply of power and, responsive to the modulation, control a component of the cleaner head. By being provided in this way, a component of the cleaner head may be controlled from the main body of the cleaning appliance without requiring the complication and cost which may be associated with providing an additional communications channel between the main body and a cleaner head. Instead, control of a component within the cleaner head is carried out based on a modulation in a power signal between the main body and the cleaner head (for example, power which is delivered to a motor within the cleaner head). That is, control of a component within the cleaner head is achieved by utilising the plurality of conductors used to supply power to also provide a communications functionality, which is concurrent or parallel with the supply of power, with communications being based on modulating the supply of power.

In embodiments, the cleaner head may comprise a motor in addition to the component, wherein the main body is configured to supply and control power to the motor, and the first controller may be configured to modulate the supply of power to the motor, the modulation being detectable by the second controller for controlling the component which is separate of the motor. For example, the motor may be provided to drive a brush bar or the like located at the cleaner head. In such arrangements, the modulation in the power supply to the motor may be configured such that operation of the motor is not unduly impacted, as explained herein.

Optionally, the plurality of conductors may comprise three conductors. Implementing the plurality of conductors as three conductors may provide a relatively simple to engineer arrangement, for example where the three conductors are to be passed along a wand of a "stick-vac" type vacuum cleaner, and may allow a relatively cheap and simple three-pin electrical connection between the main body and the cleaner head. However, it will be appreciated that in some embodiments only two conductors may be present. The conductors may be wires, for example The plurality of conductors may be at least partly included in a wand of the cleaning appliance that connects the main body to the cleaner head Optionally, the main body may comprise a three-phase inverter for driving a motor in the cleaner head. By being provided in this way, the cleaning appliance may be more ergonomic, as the weight of a three-phase inverter for driving a BLDG motor in a cleaner head is provided in the main body, and not in the cleaner head itself as in known arrangements. In particular, for "stick-vac" type vacuum cleaners, the main body is held by a user (e.g. with a handle), whereas the cleaner head is at a distance from the main body, and so by concentrating more weight in the main body the cleaning appliance is easier to hold and manipulate. In addition, by providing the three-phase inverter in the main body, the cleaner head itself may be simpler and less expensive to manufacture. In particular, in such arrangements it can be difficult and expensive to implement an additional communications channel between the main body and the cleaner head, and so utilising modulations in the power supply as a channel for controlling a component in the cleaner head may be particularly advantageous.

Optionally, the second controller may comprise either a hardware circuit (e.g., comprising an operational amplifier), or a microcontroller (e.g., an M3P430 microcontroller from Texas Instruments).

Modulating the supply of power may comprise or mean adjusting or changing or altering the supply of power. For example, the modulation may comprise or mean adjusting or changing or altering the supply of power along any one or more of the plurality of conductors.

The modulation may be a temporary modulation, for example a modulation that is applied for a predetermined period of time.

Optionally, the first controller may be configured to modulate the power supply by at least one of pausing the supply of power; adjusting a pulse-width modulation (PVVM) frequency of the supply of power; and/or adjusting a PWM pulse width of the supply of power. These may be referred to herein as different types of modulation. Modulating the supply of power to the cleaner head preferably does not adversely interfere with control or operation of a motor, and the modulation may be selected (e.g., the type of modulation) and configured (e.g., the duration of the modulation) based on hardware limitations (e.g., the max transfer rate achievable by the first controller and/or the second controller, the motor architecture). For example, pausing the supply of power may comprise turning the power supply off for a brief period (a predetermined period of time), then turning the power supply back on. In some examples, pausing the supply of power may comprise pausing the supply of power along one or more of the plurality of conductors. The brief period (or predetermined period of time) may be short enough not to interfere with motor control where appropriate, and long enough to be perceivable by the second controller. Such a time period may be less than 10 ms, for example, such as 3 ms or 4 ms. In particular, pausing the supply of power for a brief period in this way may provide more reliable control of the motor and reduce the risk of undesirable side effects such as a user hearing the modulation in the power supply (i.e., a user perceiving that power to a motor within the cleaner head has been paused). Adjusting a PVVM frequency may comprising changing the PVVM frequency from a nominal operational frequency (under which the controller and motor may operate most of the time) to another frequency (which may be higher or lower than the nominal operational frequency) within the motor's hardware and control performance limits and which also does not lead to detrimental performance of the motor. For example, a first frequency, the nominal operational frequency, may be a low frequency (e.g., 30KHz), and a second frequency may be a high frequency (e.g., 60 KHz) for example. Modulating the power signals in these ways may be advantageous as they may be readily detectable by the second controller due to the high differentiation between the power signal states (e.g., an off state vs an on state for a pause in the power supply; or a first frequency state (the nominal operational frequency) vs a second frequency state for a change in PVVN1frequency). In addition, such modulations may not unduly impact the performance of a motor (e.g., a BLDG motor) in the cleaner head to which power may be supplied).

In embodiments wherein the first controller is configured to modulate the supply of power by pausing the supply of power (e.g., pausing the supply of power along one or more of the plurality of conductors), the second controller may be configured to communicate with the first controller (e.g., by generating or sending a communication signal) during the pause in the supply of power. In this way, the cleaner head may be configured to communicate with the main body. For example, the second controller may be configured to communicate with the first controller by at least one of creating a short circuit between two of the plurality of conductors; and creating an open circuit on one of the plurality of conductors. In particular, such an arrangement may work by encoding the communication signal in back electromotive force (BEMF) from a motor in the cleaner head, where the BEMF is generated by the motor acting as a generator while it spins (while active or, more particularly in this case, as it spins in periods when no power is delivered to the motor). The BEMF is typically predictable, and so deviation from an expected pattern (i.e., the signal/message generated by the cleaner head) may be detected at the main body.

In some embodiments the first controller may be configured to cause a single modulation to the supply of power to the cleaner head, and second controller may be configured to control the component responsive to the single modulation.

In certain embodiments, the first controller may be configured to modulate the supply of power to form a sequence of the modulations (in particular, wherein the modulations are a pause in the supply of power and/or the modulation is an adjustment of the PWM frequency of the supply of power as described above), and the second controller may be configured to detect the sequence of the modulations. In some examples, the sequence of modulations may be spaced at regular time intervals, and so the sequence of modulations may thereby provide a 'heartbeat' having a specific period and/or frequency which is detectable by the second controller. By being provided in this way, the risk of mis-triggering control of the component of the cleaner head may be reduced as a sequence of modulations provides a lower risk of misidentification when compared with a single modulation.

In certain embodiments, the cleaner head may comprise a first component and a second component, and the second controller may be configured to control the first component responsive to detecting that the modulation is a first modulation type (e.g., a pause in the supply of power); and control the second component responsive to detecting that the modulation is a second modulation type (e.g., an adjustment of the PVVM frequency of the supply of power). In this way, multiple components of the cleaner head may be controlled from the main body using modulations of the power supply to the cleaner head as a communications channel, without requiring the implementation of a dedicated communications channel between the main body and the cleaner head which would introduce additional cost and complexity to the cleaning appliance.

Optionally, the first controller may be configured to modulate the supply of power to the cleaner head to encode a message, and the second controller may be configured to decode the message from the modulation. By being provided in this way, the power supply may also be used to provide unidirectional communications from the main body to the cleaner head. For example, such unidirectional communications may be used to control more complex functionality of the cleaner head, and/or control a number of additional components within the cleaner head independently.

Optionally, the component of the cleaner head may be any one or more of a light-emitting diode (LED); a laser; and/or a mechanical actuator. For example, a LED may illuminate a dark area being cleaned, a laser may illuminate dust and other large particles in order to better target areas to be cleaned, and/or a mechanical actuator may be used to move a portion of the cleaner head, such as a cover or closure over an aperture in the cleaner head which may be opened to allow large particles to be picked up by the cleaning appliance in use. The components may derive power from the supply of power to the cleaner head (e.g., to a motor within the cleaner head), for example. In some embodiments, the cleaner head may comprise a parasitic power supply for this purpose.

According to a second aspect of the present invention there is provided a method of operating a cleaning appliance, the cleaning appliance comprising a main body and a cleaner head, wherein the main body is configured to supply power to the cleaner head via a plurality of conductors; wherein the method comprises: modulating, at the main body, a supply of power to the cleaner head; detecting, at the cleaner head, a modulation in the supply of power; and, responsive to the detection, controlling a component of the cleaner head. By being provided in this way, a component of the cleaner head may be controlled from the main body of the cleaning appliance without requiring the complication and cost which may be associated with providing an additional communications channel between the main body and a cleaner head. Instead, control of a component within the cleaner head is carried out based on a modulation in a power signal between the main body and the cleaner head (e.g., power which is delivered to a motor within the cleaner head). That is, control of a component within the cleaner head is achieved by utilising the plurality of conductors used to supply power to also provide a communications functionality, which is concurrent or parallel with the supply of power, with communications being based on modulating the supply of power.

The cleaning appliance in the second aspect of the present invention may have any one or more of the features of the cleaning appliance of the first aspect of the present invention, unless incompatible with the features of the second aspect of the present invention.

In embodiments, the cleaner head may comprise a motor in addition to the component, wherein the main body is configured to supply power to the motor, a modulation in the supply of power delivered to the motor being detectable by the second controller for controlling the component which is separate of the motor. For example, the motor may be provided to drive a brush bar or the like located at the cleaner head. In such arrangements, the modulation in the power supply to the motor may be configured such that operation of the motor is not unduly impacted, as explained herein.

Optionally, modulating a supply of power to the cleaner head may comprise at least one of pausing the supply of power, for example for a brief period or predetermined period, adjusting a pulse-width modulation (PM) frequency of the supply of power; and/or adjusting a PVVIV1 pulse width of the supply of power. These may be referred to herein as different type of modulation. Modulating the supply of power to the cleaner head preferably does not adversely interfere with control or operation of a motor, and the modulation may be selected (e.g., a type of modulation) and configured (e.g., a duration of the modulation) based on hardware limitations (e.g., the max transfer rate achievable by the first controller and/or the second controller, motor architecture). For example, pausing the supply of power may comprise turning the power supply off for a brief period, then turning the power supply back on. In some examples, pausing the supply of power may comprise pausing the supply of power along one or more of the plurality of conductors. The brief period may be short enough not to interfere with motor control, and long enough to be perceivable by the second controller. Such a time period may be less than 10 ms, for example, such as 3 ms or 4 ms. In particular, pausing the supply of power for a brief period in this way may provide more reliable control of a motor and reduce the risk of undesirable side effects such as a user hearing the modulation in the power supply (i.e., a user perceiving that power to a motor within the cleaner head has been paused). Adjusting a PWM frequency may comprising changing the PVVM frequency from a nominal operational frequency (under which the controller and motor may operate most of the time) to another frequency (which may be higher or lower than the nominal operational frequency) within the motor's hardware and control performance limits and which also does not lead to detrimental performance of the motor. For example, a first frequency, the nominal operational frequency, may be a low frequency (e.g., 30KHz), and a second frequency may be a high frequency (e.g., 60 KHz) for example. Modulating the power signals in these ways may be advantageous as they may be readily detectable by the second controller due to the high differentiation between the power signal states (e.g., an off state vs an on state for a pause in the power supply; or a first frequency state (the nominal operational frequency) vs a second frequency state for a change in PWM frequency). In addition, such modulations may not unduly impact the performance of a motor (e.g., a BLDC motor) in the cleaner head to which power may be supplied).

In embodiments wherein the modulating the supply of power to the cleaner head comprises pausing the supply of power (e.g., pausing the supply of power along one or more of the plurality of conductors), the method may further comprise generating a signal to the main body by the cleaner head (e.g., to send a communication signal to the main body from the cleaner head) during the pause in the supply of power. In this way, the cleaner head may be configured to communicate with the main body. For example, generating a signal may comprise at least one of creating a short circuit between two of the plurality of conductors; and creating an open circuit on one of the plurality of conductors. In particular, such an arrangement may work by encoding the communication signal in back electromotive force (BEMF) from a motor in the cleaner head, where the BEMF is generated by the motor acting as a generator while it spins (while active or, more particularly in this case, as it spins in periods when no power is delivered to the motor). The BEMF is typically predictable, and so deviation from an expected pattern (i.e., the signal/message generated by the cleaner head) may be detected at the main body.

In certain embodiments, modulating the supply of power to the cleaner head may comprise forming a sequence of the modulations (in particular, wherein the modulations are a pause in the supply of power and/or adjusting a PVVM frequency of the supply of power as described above), such that the sequence is detectable at the cleaner head. In some examples, the sequence of modulations may be spaced at regular time intervals, and so the sequence of modulations may thereby provide a 'heartbeat' which is detectable by the second controller. By being provided in this way, the risk of mis-triggering control of the component of the cleaner head may be reduced as a sequence of modulations provides a lower risk of misidentification when compared with a single modulation.

In certain embodiments, the cleaner head may comprise a first component and a second component, and the method may further comprise determining, at the cleaner head, a type of the modulation in the supply of power; and, either: responsive to determining that the modulation is first type of modulation (e.g., a pause in the supply of power), controlling the first component; or responsive to determining that the modulation is a second type of modulation (e.g, an adjustment of the PVVM frequency of the supply of power), controlling the second component. In this way, multiple components of the cleaner head may be controlled from the main body using modulations of the power supply to the cleaner head as a communications channel, without requiring the implementation of a dedicated communications channel between the main body and the cleaner head which would introduce additional cost and complexity to the cleaning appliance.

Optionally, the modulating may comprise modulating the supply of power to the cleaner head to encode a message, and the method may further comprise decoding, at the cleaner head, the message from the modulation. In this way, the method of the second aspect of the invention may also be used to provide unidirectional communications from the main body to the cleaner head. For example, such messaging may be used to control more complex functionality of the cleaner head, and/or control a number of additional components within the cleaner head independently.

According to a third aspect of the present invention; there is provided a cleaning appliance according to the first aspect, further comprising a memory device storing instructions which, when executed, cause the first controller and the second controller to perform a method according to the second aspect of the present invention.

The invention includes the combination of the aspects and preferred features described except where such a combination is clearly impermissible or expressly avoided.

Summary of the Figures

Embodiments and experiments illustrating the principles of the invention will now be discussed with reference to the accompanying figures in which: Fig. 1 is a perspective view showing a cleaning appliance according to an embodiment of the present invention, Fig. 2 is a schematic diagram of a cleaning appliance according to an embodiment of the present invention; Fig. 3 is a flow chart showing a first method according to an embodiment of the present invention; Fig. 4 is a flow chart showing a second method according to an embodiment of the present invention; Fig 5 shows a first example of power modulation and associated control of a component; Fig. 6 shows a second example of power modulation and associated control of a component; Fig 7 shows a third example of power modulation and associated control of a component; Fig. 8 shows a fourth example of power modulation, associated control of a component, and bidirectional communication; and Fig. 9 shows example circuit diagrams enabling communication signals from a cleaner head to a main body.

Detailed Description of the Invention

Aspects and embodiments of the present invention will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned in this text are incorporated herein by reference.

Fig. 1 shows a perspective view of a cleaning appliance according to an embodiment of the present invention. In particular, the cleaning appliance is a vacuum cleaner 2. The vacuum cleaner 2 of this embodiment is a "stick-vac" type vacuum cleaner. That is, it has a cleaner head 4 which can be connected to a main body 6 by a generally tubular elongate wand 8. The cleaner head 4 is also connectable directly to the main body 6 to transform the vacuum cleaner 2 into a handheld vacuum cleaner.

The main body 6 comprises a dirt separator 10 which in this case is a cyclonic separator. The cyclonic separator has a first cyclone stage 12 comprising a single cyclone, and a second cyclone stage 14 comprising a plurality of cyclones 16 arranged in parallel. The main body 6 also has a removable filter assembly 18 provided with vents 20 through which air can be exhausted from the vacuum cleaner 2.

In this case the main body 6 of the vacuum cleaner 2 has a pistol grip 22 positioned to be held by the user. At an upper end of the pistol grip 22 is an on/off switch in the form of a trigger (not visible) which must be held (i.e. 'pulled') in order to keep the vacuum cleaner turned on. As soon as the user releases the trigger, the vacuum cleaner is turned off Positioned beneath a lower end of the pistol grip 22 is a battery pack 26 which comprises a plurality of rechargeable cells (not visible). A controller in the form of a PCB (not visible), and a vacuum motor (not visible) comprising a fan driven by an electric motor are provided in the main body 6 behind the dirt separator 10.

It will be appreciated that a number of different cleaner heads may be connected to the main body 6, either directly or via the wand 8. Each cleaner head may comprise different components (e.g., motors, lights), some of which may need to be powered and controlled from the main body. The vacuum cleaner 2 is therefore configured to allow control of components of the cleaner head 4 based on modulation in a power signal between the main body 6 and the cleaner head 4 as set out below. In particular, as set out below, the main body 6 is configured to supply power to a motor within the cleaner head 4 (e.g., a motor for driving a brush bar or the like), and modulations in the supply of power to the motor may be used to control another component of the cleaner head (i.e. other than the motor).

Fig. 2 shows a schematic diagram of a cleaning appliance 100 according to an embodiment of the present invention. The cleaner appliance 100 may be a vacuum cleaner, for example as described above with respect to Fig. 1.

The cleaning appliance 100 comprises a main body 110 and a cleaner head 120, wherein the main body 110 is configured to supply power to the cleaner head 120 via a plurality of conductors 130. In particular, as shown in Fig. 2, the plurality of conductors 130 comprises three conductors, and they may be in the form of wires, for example. However, it will be appreciated that according to certain embodiments of the present invention, the plurality of conductors 130 may comprise only two conductors (e.g., where a motor in the cleaner head 120 is a brushed motor), and so one of the conductors 130 is shown as a dotted line to emphasise that embodiments of the present invention may comprise any suitable number of conductors 130.

The main body 110 comprises a first controller 111, for example comprising a PCBA, which may be a main controller for the cleaning appliance 100 such that it is responsible for other operations of the cleaning appliance 100 (e.g., controlling a vacuum motor within the main body 110) as well as communications over the plurality of conductors 130 as described herein. The main body 110 also comprises a power PCBA 112, which may derive power from a battery pack, for example. The power PCBA 112 supplies power to a three-phase inverter 113 for driving a brushless DC (BLDC) motor 121 which is located in the cleaner head 120, with power being delivered to the BLDC motor 121 from the inverter 113 using the plurality of conductors 130. The first controller 111 is configured to send instructions to the power PCBA 112 for controlling the BLDG motor 121 to modulate the power supply for controlling a component 124 of the cleaner head 120, as described in more detail below. For example, the cleaning appliance 100 may comprise a memory device (e.g., on the same PCBA as the first controller 111) storing instructions which, when executed, cause the first controller 111 to perform a control method as described below.

The cleaner head 120 comprises a BLDC motor 121 which receives power from the main body 110 via the plurality of conductors 130. The three-phase inverter 113 in the main body 110 is configured to drive the BLDG motor 121. However, as outlined above, it will be appreciated that in certain embodiments of the invention the motor in the cleaner head 120 may be a brushed motor, requiring only two conductors to pass between the main body 110 and the cleaner head 120.

The cleaner head comprises a component 124, which may be any additional component which is advantageously controllable from the main body 110 (e.g, controllable by a user of the cleaning appliance 100). For example, the component 124 may be a light-emitting diode (e.g., to illuminate a dark area being cleaned), a laser (e.g., to illuminate dust and other large particles in order to better target areas to be cleaned), or an actuator (e.g., a mechanical actuator may be used to move a portion of the cleaner head 120, such as a cover or closure over an aperture in the cleaner head 120 which may be opened to allow large particles to be picked up by the cleaning appliance 100 in use). For example, in response to a detected modulation, the second controller 123 may control a LED or laser to be switched on, or switched off, or may operate an actuator (e.g., to open or close an aperture in the cleaner head 120).

The cleaner head 120 comprises a second controller 123 which is configured to detect modulations in the supply of power from the main body 110 and, responsive to such detection, control the component 124. For example, the second controller 123 may be implemented as either a hardware circuit or as a microcontroller. In some embodiments, the cleaner head may comprise more than one component, each of which may be controlled by the second controller 123 responsive to a different detected modulation in the supply of power. Additionally or alternatively, the second controller 123 may be configured to decode a message which the first controller 111 has encoded in modulations in the supply of power. For example, such messages may be used to determine which of a plurality of components in the cleaner head 120 is to be controlled by the second controller 123.

In order to power the second controller 123 and the component 124, the cleaner head 120 comprises a parasitic power supply 122 which is connected to derive power from the plurality of conductors 130.

Fig. 3 is a flow chart showing a method 200 of operating a cleaning appliance, according to an embodiment of the present invention. For example, the method 200 may be applicable to a cleaning appliance 100 as described above with respect to Fig. 2. In particular, the method 200 is usable in a cleaning device (such as a vacuum cleaner) which comprises a main body and a cleaner head, wherein the main body is configured to supply power to the cleaner head via a plurality of conductors.

In a first step 201, a supply of power to the cleaner head from the main body is modulated. For example, a first controller in the main body may controller the power supply to be modulated. Modulating the supply of power may comprise pausing the supply of power for a predetermined period or brief period (e.g., 3-4 ms), adjusting a PWM frequency of the supply of power, and/or adjusting a PWM pulse width of the supply of power. In some examples, modulating the supply of power may comprise forming a sequence of modulations, as described in more detail below.

At a second step 202, the modulation in the supply of power is detected at the cleaner head. For example, a second controller in the cleaner head may detect the modulation.

In a third step 203, the type of modulation is determined. For example, it is determined whether the modulation in the supply of power is first modulation type (e.g., a pause in the supply of power) or second type (e.g., an adjustment in the PWM frequency in the supply of power). For example, the second controller in the cleaner head determines the type of modulation.

Finally, at step 204, responsive to the detection of the modulation, and a determination of the type of modulation, a component of the cleaner head is controlled (e.g., controlled by the second controller of the cleaner head). For example, the component which is controlled may be dependent on the type of modulation. For example, responsive to determining that the modulation is first type (e.g., a pause in the supply of power), a first component may be controlled or, responsive to determining that the modulation is a second type (e.g., an adjustment of the PWM frequency of the supply of power), a second component may be controlled.

Fig. 4 is a flow chart showing a further method 300 of operating a cleaning appliance, according to an embodiment of the present invention. For example, the method 300 may be applicable to a cleaning appliance 100 as described above with respect to Fig. 2. In particular, the method 300 is usable in a cleaning device (such as a vacuum cleaner) which comprises a main body and a cleaner head, wherein the main body is configured to supply power to the cleaner head via a plurality of conductors.

In a first step 301, a supply of power to the cleaner head from the main body is modulated to encode a message. For example, a first controller in the main body may controller the power supply to be modulated. Modulating the supply of power to encode a message may comprise pausing the supply of power for a predetermined period or brief period (e.g., 3-4 ms), adjusting a PWM frequency of the supply of power, and/or adjusting a PVVM pulse width of the supply of power, wherein the arrangement of such modulations may encode a message (as described in more detail below).

At a second step 302, the modulation in the supply of power is detected at the cleaner head. For example, a second controller in the cleaner head may detect the modulation.

In a third step 303, the message is decoded from the demodulation at the cleaner head. For example, the second controller in the cleaner head may decode the message.

Finally, at step 304, responsive to the detection of the modulation and in accordance with the decoded message, a component of the cleaner head is controlled (e.g., controlled by the second controller of the cleaner head). For example, the cleaner head may comprise multiple components, and a component which is controlled may be determined by the contents of the decoded message. In other examples, the type of control which is carried out (e.g., switching on or oft or adjusting a power level) may be determined according to the contents of the decoded message.

Fig. 5 shows an example of power modulation and associated control of a component in a cleaner head of a cleaning appliance, which may be used in embodiments of the present invention. A first graph 410 shows the supply of power to a cleaner head with time, and a second graph 420 shows the state of a component of the cleaner head, which is controlled by a second controller. In this example, the component of the cleaner head may be 'on' or 'off, but it will be appreciated that other control operations or operational modes may be present, and may depend on the component which is controlled, for example. In this example, the component which is controlled may be a laser or a light, for example, which may be turned on or off by the second controller. For example, such control may be derived from a user input, for example an input at the main body of the cleaning appliance.

In the cleaning appliance, a main body comprises a first controller which is configured to modulate the supply of power to the cleaner head, As shown in graph 410, the supply of power to the cleaner head (e.g., to a BLDC motor within a cleaner head) comprises two modulations 411a, 411b. For example, each modulation 411a, 411b may be a pause in the supply of power, an adjustment in the PWM frequency of the supply of power (e.g., a change in the frequency from 30 KHz in normal operation to 60 KHz during each modulation 411a, 411b), or an adjustment in a PVVM pulse width of the supply of power. These modulations are triggered by the first controller, for example responsive to a user input, in order to control the component of the cleaner head.

Prior to the first modulation 411a, the second controller operates the component such that it is on, as shown in graph 420. However, when the first modulation 411a is detected by the second controller, the second controller controls the component to switch to the off state. The off state of the component is maintained until the second modulation 411b is detected, whereupon the second controller controls the component to switch to the on state.

As shown in Fig. 5, the second controller may detect the end of the modulation, for example a time at which the normal power supply is resumed after a pause in the power supply, or a time at which the normal PVVM frequency is resumed after an adjustment in the PVVM frequency, and the component is operated based on this detection. Of course, in other embodiments the second controller may detect the start of the modulation, or another time point in the modulation.

Fig. 6 shows a second example of power modulation and associated control of a component in a cleaner head, which may be used in embodiments of the present invention. A first graph 510 shows the supply of power to a cleaner head with time, and a second graph 520 shows the state of a component of the cleaner head, which is controlled by a second controller, with time. In this example, the component of the cleaner head may be 'on' or 'off, but it will be appreciated that other control operations or operational modes may be present, and may depend on the component which is controlled, for example. In this example, the component which is controlled may be a laser or a light, for example, which may be turned on or off by the second controller. For example, such control may be derived from a user input, for example an input at the main body of the cleaning appliance. The main body comprises a first controller which is configured to modulate the supply of power to the cleaner head.

As shown in graph 510, in this example the first controller modulates the supply of power to form a sequence of modulations 511a, 511b... 511n. For example, each modulation 511a, 511b... 511n may be a pause in the supply of power, or an adjustment in the PVVM frequency of the supply of power (e.g., a change in the frequency from 30 KHz in normal operation to 60 KHz during each modulation 511a, 511b... 511n), or an adjustment in the PVVM pulse width of the supply of power. The sequence of modulations may last for a predetermined period of time, or the duration of the sequence of modulations may be controlled based on a user input, for example. The sequence of modulations 511a, 511b... 511n may be spaced at regular time intervals and/or at a regular frequency to aid detection by the second controller of the cleaner head. In this way, the regular spacing of the sequence of modulations 511a, 511b... 511n may be said to form a 'heartbeat' which is detectable by the second controller.

Prior to detection of the sequence of modulations 511a, 511b... 511n, the second controller operates the component such that is off, as shown in graph 520. However, when the sequence of modulations 511a, 511b... 511n is detected by the second controller, the second controller controls the component to switch to the on state (e.g., turns on a laser or a light). The on state is maintained until the second controller no longer detects the sequence of modulations 511a, 511b... 511n, whereupon the second controller controls the component to switch to the off state.

Fig. 7 shows a third example of power modulation and associated control of a component in a cleaner head, which may be used in embodiments of the present invention. In particular, the third example demonstrates how modulations in the supply of power may be used for unidirectional communications from a main body to a cleaner head of a cleaning appliance. A first graph 610 shows the supply of power to a cleaner head with time, wherein modulations in the supply of power encode a message, and a second graph 620 shows how modulations in the supply of power may be decoded (e.g., by a second controller) in order to obtain a message.

In this example the first controller modulates the supply of power to encode a message, as shown in graph 610. For example, a modulation in the supply of power may be detected by the second controller and decoded as a 10', and a period in the supply of power may be detected by the second controller and decoded as a '1'. In this way, unidirectional communication may take place from the main body to the cleaner head.

For example, to encode a first message (MSG1), the first controller may encode '0100' in the supply of power by providing a first modulation 611a of a predetermined length, followed by a period 611b without a modulation having the same length, and a second modulation 611c of twice the predetermined length.

This is detected by the second controller, which decodes the message to output '0100', as shown in graph 620. For example, the first message may be an instruction to control a first component of the cleaner head, or perform some particular control operation.

Similarly, to encode a second message (MSG2), the first controller may encode '0101' in the supply of power by providing a first modulation 611d of a predetermined length, followed by a period 611e without a modulation having the same length, and a second modulation 611f of the same predetermined length, and a final period without a modulation 611g. This is detected by the second controller, which decodes the message to output '0101', as shown in graph 620. For example, the second message may be an instruction to control a second component of the cleaner head, or perform some particular control operation.

Fig. 8 shows a fourth example of power modulation and associated control of a component in a cleaner head, which may be used in embodiments of the present invention. In particular, the fourth example demonstrates how bidirectional communications may be implemented between a main body and a cleaner head. In particular, in this example, a cleaner head communicates with the main body (e.g., by generating and sending a communication signal to the main body) during periods when the power supply to the motor is switched off (e.g., during a pause in the supply of power).

In this fourth example, the first controller modulates the supply of power to encode a message in much the same way as described above with respect to Fig. 7, in particular an embodiment of Fig. 7 wherein the modulations in the supply of power are brief pauses. Description of these features is therefore not repeated, and like reference numerals are used to indicate like features. Generally, however, the first graph 610 shows the supply of power to a cleaner head with time, wherein the modulations in the supply of power (wherein these modulations are brief pauses in the supply of power) encode a message from the main body to the cleaner head, and a second graph 620 shows how the modulations in the supply of power may be decoded (e.g., by a second controller) in order to obtain a message. A third graph 710 shows communication signals 711, 712 from the cleaner head to the main body, where the communication signals may be decoded (e.g., by a first controller). The communication signals 711, 712 may be used as feedback, for example to enhance the control of the cleaner head from the main body (e.g., by the first controller). For example, the cleaner head may comprise one or more sensors (e.g., temperature or pressure sensors), and the second controller may use the bidirectional communication capability to notify the main body of hardware critical operation (e.g., a cleaner head blockage or hardware within the cleaner head being above a predetermined temperature). The communication signals 711, 712 may comprise a pulse (e.g., a pulse having a variable length) or a plurality of pulses, for example. In embodiments, each pulse may be a pulse of power along the plurality of conductors. Another example of how such communication signals 711, 712 may be implemented is described below with respect to Fig. 9.

During the brief pauses in the supply of power to the cleaner head, the main body (e.g., the first controller) may be configured to observe the status of the motor in the cleaner head. This is typically performed by monitoring the back electromotive force (BEMF). The second controller may therefore send a communication signal 711, 712 by modifying the BEMF. For example, the second controller may perform what is known as "motor active breaking" by creating a short circuit between two of the plurality of conductors. In another example, the second controller may create an open circuit on one of plurality of conductors to show an open circuit on one of the motor phases, such that the BEMF is not detectable by the main body. Fig. 9 shows example circuit diagrams (of part of a circuit within a cleaner head, such as cleaner head 120 as described above) of how such communication signals may be generated by the second controller.

Fig. 9a shows a circuit diagram wherein a second controller 123 is configured to control a switch 801 which is arranged to create a short circuit between two of the plurality of conductors 130 when the switch 801 is closed. In this way, the second controller 123 may send a communication signal, which is detectable by a first controller in a main body as a break in the back electromotive force (BEMF) which is normally sensed by the first controller. For example, the switch 801 may be a bidirectional power switch, or any other suitable controllable switch.

Fig. 9b shows a circuit diagram wherein a second controller 123 is configured to control a switch 802 which is arranged to create an open circuit on one of the plurality of conductors 130 when the switch 802 is open. In this way, the second controller 123 may send a communication signal, which is detectable by a first controller in a main body as a break in the BEMF which is normally sensed by the first controller.

For example, the switch 802 may be a bidirectional power switch, or any other suitable controllable switch.

The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purposes of improving the understanding of a reader. The inventors do not wish to be bound by any of these theoretical explanations.

Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

Throughout this specification, including the claims which follow, unless the context requires otherwise, the word "comprise" and "include", and variations such as "comprises", "comprising", and "including" will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

It must be noted that, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" one particular value, and/or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent "about," it will be understood that the particular value forms another embodiment. The term "about" in relation to a numerical value is optional and means for example +/-10%.

Claims

Claims: 1. A cleaning appliance comprising a main body and a cleaner head, wherein the main body is configured to supply power to the cleaner head via a plurality of conductors, wherein: the main body comprises a first controller configured to modulate the supply of power to the cleaner head, and the cleaner head comprises a second controller configured to detect a modulation in the supply of power and, responsive to the modulation, control a component of the cleaner head.
2. A cleaning appliance according to claim 1, wherein the plurality of conductors comprises three conductors.
3. A cleaning appliance according to claim 1 or claim 2, wherein the main body comprises a three-phase inverter for driving a motor in the cleaner head.
4. A cleaning appliance according to any one of the preceding claims, wherein the second controller comprises either: a hardware circuit; or a microcontroller.
5. A cleaning appliance according to any one of the preceding claims, wherein the first controller is configured to modulate the power supply by at least one of: pausing the supply of power; adjusting a pulse-width modulation, P1NM, frequency of the supply of power; and/or adjusting a PWM pulse width of the supply of power.
6. A cleaning appliance according to claims, wherein the first controller is configured to modulate the supply of power by pausing the supply of power, and wherein the second controller is configured to communicate with the first controller during the pause in the supply of power.
7. A cleaning appliance according to claim 6, wherein the second controller is configured to communicate with the first controller by at least one of: creating a short circuit between two of the plurality of conductors; and creating an open circuit on one of the plurality of conductors.
8. A cleaning appliance according to any one of claims 5 to 7, wherein the first controller is configured to modulate the supply of power to form a sequence of the modulations, and wherein the second controller is configured to detect the sequence of the modulations.
9. A cleaning appliance according to any one of claims 5 to 7, wherein the cleaner head comprises a first component and a second component, and wherein the second controller is configured to: control the first component responsive to detecting that the modulation is a first modulation type; and control the second component responsive to detecting that the modulation is a second modulation type.
10. A cleaning appliance according to any one of the preceding claims, wherein the first controller is configured to modulate the supply of power to the cleaner head to encode a message; and wherein the second controller is configured to decode the message from the modulation
11. A cleaning appliance according to any one of the preceding claims, wherein the component of the cleaner head is any one or more of: a light-emitting diode; a laser; and/or a mechanical actuator.
12. A method of operating a cleaning appliance, the cleaning appliance comprising a main body and a cleaner head, wherein the main body is configured to supply power to the cleaner head via a plurality of conductors; wherein the method comprises: modulating, at the main body, a supply of power to the cleaner head; detecting, at the cleaner head, a modulation in the supply of power; and responsive to the detection, controlling a component of the cleaner head.
13. A method of operating a cleaning appliance according to claim 12, wherein modulating a supply of power to the cleaner head comprises at least one of: pausing the supply of power; adjusting a pulse-width modulation, PVVM, frequency of the supply of power; and/or adjusting a PWM pulse width of the supply of power.
14. A method of operating a cleaning appliance according to claim 11, wherein the modulating a supply of power to the cleaner head comprises pausing the supply of power, and wherein the method further comprises generating a signal to the main body by the cleaner head during the pause in the supply of power.
15. A method of operating a cleaning appliance according to claim 14, wherein generating a signal comprises at least one of creating a short circuit between two of the plurality of conductors; and creating an open circuit on one of the plurality of conductors.
16. A method of operating a cleaning appliance according to any one of claims 13 to 15, wherein modulating the supply of power to the cleaner head comprises forming a sequence of the modulations, such that the sequence of the modulations is detectable at the cleaner head.
17. A method of operating a cleaning appliance according to any one of claims 13 to 15, wherein the cleaner head comprises a first component and a second component, and wherein the method further comprises: determining, at the cleaner head, a type of the modulation in the supply of power; and, either: responsive to determining that the modulation is a first type of modulation, controlling the first component; or responsive to determining that the modulation is aa second type of modulation, controlling the second component
18. A method of operating a cleaning appliance according to any one of claims 12 to 17, wherein the modulating comprises modulating the supply of power to the cleaner head to encode a message, and wherein the method further comprises decoding, at the cleaner head, the message from the modulation.
19. A cleaning appliance according to any one of claims 1 to 11, wherein the cleaning appliance comprises a memory device storing instructions which, when executed, cause the first controller and the second controller to perform a control method according to any one of claims 12 to 18.