WO2025036690A1

WO2025036690A1 - Detection of a user touching a device based on changes in rf signal strength

Info

Publication number: WO2025036690A1
Application number: PCT/EP2024/071453
Authority: WO
Inventors: Bartel Marinus Van De Sluis; Harry Broers; Leendert Teunis Rozendaal; Samantha Tina PEETERS; Matthias Wendt
Original assignee: Signify Holding B.V.
Priority date: 2023-08-15
Filing date: 2024-07-29
Publication date: 2025-02-20

Abstract

A system (40) for detecting a user touching a device (41) is configured to obtain signal characteristics of one or more received radiofrequency signals which are received or transmitted by the device via an antenna (48) comprised in the device, detect current temporary distortions of the one or more received radiofrequency signals based on the obtained signal characteristics, and detect whether the user is touching the device based on a result of the detection.

Description

Detection of a user touching a device based on changes in RF signal strength

FIELD OF THE INVENTION

The invention relates to a system for detecting a user touching a device.

The invention further relates to a method of detecting a user touching a device. The invention also relates to a computer program product enabling a computer system to perform such a method.

BACKGROUND OF THE INVENTION

Many types of devices can be controlled with buttons or a touch screen on the device itself, e.g. TVs, monitors, refrigerators, thermostats. However, certain types of devices have no control elements on the device itself, e.g. light bulbs and certain connected luminaires, or have limited control elements on the device itself, e.g. certain types of smart speakers and certain luminaires. A control element on devices that are within reach of the user (e.g. a portable light, a table lamp, a desk lamp) is often appreciated by users, but devices may lack this functionality due to cost. For example, many connected lamps lack this functionality due to cost, or due lack of space for such control element.

Control elements on devices normally comprise one or more mechanical input elements and/or one or more touch input elements and/or one or more tap input elements. KR 10-2014-0073619 describes an example of a lighting device with a touch input element. This lighting device comprises a sensing unit detecting a change in capacitance caused by a touch. A user may therewith turn on/off the lighting device or adjust the brightness of the light by using a finger or an input device. Although this lighting device detects touch by using an antenna that is needed for another purpose anyway, this lighting device also comprises a conductive layer and a conductive film, which may be too costly for certain types of devices or require additional space.

SUMMARY OF THE INVENTION

It is a first object of the invention to provide a system, which is able to detect a user touching a device in a relatively cheap and/or space-efficient manner. It is a second object of the invention to provide a method, which can be used for detecting a user touching a device in a relatively cheap and/or space-efficient manner.

In a first aspect of the invention, the object is achieved by a system for detecting a user touching a device, wherein said device is a lighting device, said system comprising: at least one receiver; and at least one processor configured to:

- obtain signal characteristics of one or more received radiofrequency signals via said at least one receiver, said one or more radiofrequency signals being received or transmitted by said device via an antenna comprised in said device,

- detect current temporary distortions of said one or more received radiofrequency signals based on said obtained signal characteristics, and

- detect whether said user is touching said device based on a result of said detection,

- determine a duration of a touch action and/or a quantity of touch actions based on characteristics of the current temporary distortions,

- identify a kind of touch action based on the duration of the touch action and/or the quantity of touch actions determined,

- select a control action from a plurality of control actions based on the kind of touch action, and

- control said device according to said control action upon detecting said user touching said device.

With more and more devices becoming wirelessly controllable, RF sensing will quickly become a mature sensing technology and a commodity in many applications, e.g. lighting applications. As a result, many RF device processors will continuously or frequently monitor RF signals. Even without RF sensing will certain types of devices, e.g. radar sensors and Wi-Fi devices, continuously or frequently monitor RF signals. This makes it possible to detect touch in a relative cheap and space-efficient manner, by monitoring changes in signal characteristics of the RF signal(s), if the (RF) antenna of the device extends to the inside or the outside of a surface of the device such that it can double as a touch sensor. Said device may be a lighting device, for example. Said device may use RF sensing to detect presence, for example.

Said antenna of said device may be exposed at said surface of said device or covered by a conductive finishing on said surface of said device or mounted directly below a housing of said device. For example, a metal antenna may be completely exposed at the surface of the device, or may be covered by a (thin) conductive finishing surface, or may be mounted underneath the normal (plastic) enclosure, e.g. for galvanic isolation (lamp without isolating transformer).

A visual indication may be provided on the outside of a surface of said device, said visual indication indicating where said user should touch said device. This increases the probability that the user touching the device is detected. A part of the surface to which the antenna extends may be visually marked, for example.

Said at least one processor may be configured to distinguish between a first area of a housing of said device being touched and a second area of said housing of said device being touched based on said result of said detection. For example, said first area of said housing may be closer to said antenna of said device than said second area of said housing. A first control action may be performed when the user touches the first area and a second control action or no control action may be performed when the user touches the second area.

Said at least one processor may be configured to distinguish between different kinds of touch actions. This makes it possible for the user to select from a plurality of control actions by performing a certain kind of touch action. For example, said at least one processor may be configured to determine a duration of a touch action and/or a quantity of touch actions based on characteristics of said current temporary distortions, and distinguish between said different kinds of touch actions based on said duration of said touch action and/or said quantity of touch actions. This may be used to distinguish, for example, between short tap (e.g. 200-500ms), long tap (e.g. 500-1800ms) and double tap (e.g. two signal drops in 800ms).

Said at least one processor may be configured to compare said signal characteristics of said one or more received radiofrequency signals with stored characteristics of temporary distortions, and detect said current temporary distortions based on a result of said comparison. The stored characteristics may comprise characteristics of one or more received reference radiofrequency signals, but this is not required; the stored characteristics may comprise a simple pre-defined threshold for example. The stored characteristics may comprise reference changes in channel state and/or received signal strength, for example.

Comparing one or more changes in signal strength of said one or more received radiofrequency signals with one or more reference changes in signal strength may comprise comparing an amount of drop in signal strength or a steepness of drop in signal strength, e.g. in order to distinguish a user touching the device from RF sensing events. For example, the system may detect the user touching the device if it sees an instant 20-35% drop in signal strength. Since RF sensing is for objects in the room which are further away than a user touching the device, the drop will be larger if the user touches the device. Furthermore, a hand close by will cause a steep drop, while a human walking into an RF sensing area will cause a gradual drop.

Said at least one processor may be configured to ask said user or a different user to touch said device in a designated area in a certain period, obtain signal characteristics of one or more received reference radiofrequency signals via said at least one receiver, said one or more reference radiofrequency signals being received or transmitted by said device via said antenna in said certain period, store said characteristics of said one or more received reference radiofrequency signals in a memory as said stored characteristics of temporary distortions, compare said characteristics of said one or more received radiofrequency signals with said stored characteristics of temporary distortions, and detect said current temporary distortions based on a result of said comparison. This training may use characteristics like the amount of drop in signal strength and/or the steepness of drop in signal strength to learn to distinguish touching from (other) RF disturbances related to RF sensing. Other characteristics, e.g. variations in the channel state, may also be used.

By letting one or more users train the system which signal characteristics, e.g. reference changes in signal strength, correspond to touch actions, the probability that the user touching the device is detected may be increased. Alternatively or additionally, the stored characteristics of temporary distortions may have been determined and provided by the manufacturer of the device. For example, a manufacturer reference level may be used as default but may be adjusted by the user if the user wants to optimize the system.

Alternatively, current temporary distortions of said one or more received radiofrequency signals may be detected by performing anomaly detection, e.g. on signal strength and/or channel state data. The channel state may be determined from channel state information (CSI), i.e. the measured channel properties of a wireless communication link. Anomaly detection involves the identification of observations and patterns that deviate drastically from the expected data. These anomalies, often referred to as anomalies, outliers, discordant observations, exceptions are a minority. Unsupervised anomaly detection algorithms (like isolation forest and autoencoders) learn a representation of normal data to detect rare deviations. Next to learning these representations on existing data, these representations can also be learned online on the incoming sensor data stream. Said one or more radiofrequency signals may comprise multiple radiofrequency signals, an average duration of intervals between consecutive ones of said multiple radiofrequency signals being at most one second. When at least one radiofrequency signal is received each second, good touch detection results may be achieved. A lower rate may be sufficient for other RF sensing applications, even when the user is near the device, or may be sufficient when RF sensing is (temporarily) disabled. The radiofrequency signals may be transmitted with a fixed or variable message spacing. When one or more users are able to train the system which signal characteristics, e.g. reference changes in signal strength, correspond to touch actions, pattern of messages being transmitted/received may be changed (e.g. more messages) during the training session for optimal detection and training.

Said one or more radiofrequency signals may comprise multiple radiofrequency signals and said at least one processor may be configured to detect a user within a predetermined distance of said device, and increase a rate at which said multiple radiofrequency signals are transmitted while said user is detected within said predetermined distance of said device. This allows more accurate tap detection when the user is near without wasting the additional RF bandwidth for (accurate) tap detection when no one is (detected to be) near.

Said at least one processor may be configured to identify said user, obtain a user profile associated with said user, select a control action based on said user profile, and perform said control action upon detecting said user touching said device. This makes it possible to personalize the control action performed when a user touches the device.

In a second aspect of the invention, the object is achieved by a method of detecting a user touching a device, wherein said device is a lighting device, said method comprising:

- obtaining signal characteristics of one or more received radiofrequency signals, said one or more radiofrequency signals being received or transmitted by said device via an antenna comprised in said device,

- detecting current temporary distortions of said one or more received radiofrequency signals based on said obtained signal characteristics,

- detecting whether said user is touching said device based on a result of said detection,

- determining a duration of a touch action and/or a quantity of touch actions based on characteristics of the current temporary distortions, - identifying a kind of touch action based on the duration of the touch action and/or the quantity of touch actions determined,

- selecting a control action from a plurality of control actions based on the kind of touch action, and

- controlling said device according to said control action upon detecting said user touching said device.

Moreover, a computer program for carrying out the methods described herein, as well as a non-transitory computer readable storage-medium storing the computer program are provided. A computer program may, for example, be downloaded by or uploaded to an existing device or be stored upon manufacturing of these systems.

A non-transitory computer-readable storage medium stores at least one software code portion, the software code portion, when executed or processed by a computer, being configured to perform executable operations for detecting a user touching a device.

The executable operations comprise obtaining signal characteristics of one or more received radiofrequency signals, said one or more radiofrequency signals being received or transmitted by said device via an antenna comprised in said device, detecting current temporary distortions of said one or more received radiofrequency signals based on said obtained signal characteristics, and detecting whether said user is touching said device based on a result of said detection.

As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a device, a method or a computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, microcode, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a "circuit", "module" or "system." Functions described in this disclosure may be implemented as an algorithm executed by a processor/microprocessor of a computer. Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied, e.g., stored, thereon.

Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a computer readable storage medium may include, but are not limited to, the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of the present invention, a computer readable storage medium may be any tangible medium that can contain, or store, a program for use by or in connection with an instruction execution system, apparatus, or device.

A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber, cable, RF, etc., or any suitable combination of the foregoing. Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java(TM), Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer, or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).

Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor, in particular a microprocessor or a central processing unit (CPU), of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer, other programmable data processing apparatus, or other devices create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.

The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of devices, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the blocks may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

BRIEF DESCRIPTION OF THE DRAWINGS These and other aspects of the invention are apparent from and will be further elucidated, by way of example, with reference to the drawings, in which:

Fig. 1 is a block diagram of a first embodiment of the system;

Fig. 2 is a block diagram of a second embodiment of the system;

Fig. 3 shows a third embodiment of the device;

Fig. 4 shows a fourth embodiment of the device;

Fig. 5 shows a fifth embodiment of the device;

Fig. 6 is a flow diagram of a first embodiment of the method;

Fig. 7 is a flow diagram of a second embodiment of the method;

Fig. 8 is a flow diagram of a third embodiment of the method;

Fig. 9 is a flow diagram of a fourth embodiment of the method;

Fig. 10 is a flow diagram of a fifth embodiment of the method; and

Fig. 11 is a block diagram of an exemplary data processing system for performing the method of the invention.

Corresponding elements in the drawings are denoted by the same reference numeral.

DETAILED DESCRIPTION

Fig. 1 shows a first embodiment of the system for detecting a user touching a device. In the first embodiment of Fig. 1, the system is a lighting system 10 which comprises a bridge 1, e.g. a Philips Hue bridge, and lighting devices 11-13. The bridge 1 detects whether a user is touching lighting device 11. The lighting device 11 comprises an antenna 48.

The bridge 1 communicates with lighting devices 11-13, e.g. using Zigbee technology. Lighting devices 11-13 may be Hue lamps, for example. The bridge 1 is connected to the wireless LAN access point 25, e.g. via Ethernet or Wi-Fi. In the example of Fig. 1, a mobile device 21 is also connected to the wireless LAN access point 25, e.g. via WiFi. Mobile device 21 can be used to control the lighting devices 11-13.

The bridge 1 comprises a receiver 3, a transmitter 4, a processor 5, and a memory 7. The processor 5 is configured to obtain signal characteristics, e.g. signal strengths, of one or more received radiofrequency signals via the receiver 3. The one or more radiofrequency signals are received or transmitted by the lighting device 11 via the antenna 48 comprised in the lighting device 11. The one or more radiofrequency signals may comprise RF signals received by the lighting device 11 from the bridge 1 and/or RF signals received by the lighting device 11 from the lighting devices 12 and 13 and/or RF signals transmitted by the lighting device 11 to the bridge 1 and/or RF signals transmitted by the lighting device 11 to the lighting devices 12 and 13, for example.

The processor 5 is further configured to detect current temporary distortions of the one or more received radiofrequency signals based on the obtained signal characteristics and detect whether the user is touching the lighting device 11 based on a result of the comparison detection.

Since the antenna 48 of the lighting device 11 extends to the inside or the outside of a surface of the lighting device 11, the user touching the lighting device 11 near the spot at which the antenna 48 extends to the inside or the outside of the surface causes a change in RF signal characteristics, e.g. a reduction in signal strengths, of the one or more radiofrequency signals received or transmitted by the lighting device 11 via the antenna 48. This makes it possible for the bridge 1 to detect whether the user is touching the lighting device 11 based on the changes in RF signal characteristics, e.g. signal strengths. This is especially beneficial for luminaires which are within reach of a user, such as a table lamp, a desk lamp, a bedside lamp, or a floor lamp.

The antenna 48 of the lighting device 11 extends all the way to the inside or the outside of the surface of the lighting device 11 or extends towards near the inside or the outside of the surface of the lighting device 11. The antenna 48 may be exposed at the surface of the lighting device 11 or covered by a conductive finishing on the surface of the lighting device 11, for example. For instance, the housing of the lighting device may have a small cavity through which the (end of the) antenna reaches the luminaire surface or connects to a small conductive area. Alternatively, the antenna 48 may be mounted directly below the (e.g. plastic) surface of the lighting device 11, e.g. for galvanic isolation (lamp without isolating transformer), for example.

The processor 5 may be configured to compare the signal characteristics of the one or more received radiofrequency signals with stored characteristics of temporary distortions and detect the current temporary distortions based on a result of the comparison. The stored characteristics may comprise characteristics of one or more received reference radiofrequency signals, but this is not required; the stored characteristics may comprise a simple pre-defined threshold for example. The stored characteristics may comprise reference changes in channel state and/or received signal strength, for example. Alternatively, the processor 5 may be configured to detect the current temporary distortions of the one or more received radiofrequency signals by performing anomaly detection. In the embodiment of Fig. 1, a visual indication 49 is provided on the outside of a surface of the lighting device 11. The visual indication 49 indicates where the user should touch the lighting device 11. Some lights already have an indication where the antenna is. For example, the Hue GU10 lamp has a metal can with a plastic inset which was designed to function as an optimal way to get the RF signal out of the metal can. This plastic inset may function as a natural “touch me here” point and as a touch area, since blocking that area with a hand will significantly impact the RF performance.

If the one or more radiofrequency signals comprise RF signals received by the lighting device 11, the characteristics of these RF signals may be reported by the lighting device 11 to the bridge 1. If the one or more radiofrequency signals comprise RF signals received by lighting device 12 and/or 13 from lighting device 11, the characteristics of these RF signals may be reported by lighting device 12 and/or 13 to the bridge 1.

The processor 5 is configured to distinguish changes in RF signal characteristics that are the result of touch actions from other changes in RF signal characteristics. For instance, a touch action may cause a temporary instant drop in signal strength of about 20-35% which lasts at most a few seconds after which the signal instantly improves again back to its original strength.

The one or more radiofrequency signals may comprise multiple radiofrequency signals which are transmitted such that an average duration of intervals between consecutive ones of the multiple radiofrequency signals is at most one second. The radiofrequency signals may be transmitted with a fixed or variable message spacing. When at least one radiofrequency signal is received each five seconds, good touch detection results may be achieved. Every Zigbee device transmits an identifier every 15 seconds, the so-called “Zigbee Link Status message”. Each Zigbee device will receive the Link Status messages from the other Zigbee devices (which are randomly spread over time), so with 15 Zigbee devices within RF range (in the example of Fig.1, only further lighting devices 12 and 13 are present), the lighting device 11 would (on average) receive one such message every second. This may be sufficient to detect a first touch, although it is likely not sufficient to detect the kind of touch.

Devices involved in RF sensing will transmit and receive messages at a much higher rate (e.g. at least one message every 400 milliseconds) so the interval between messages is much shorter and this allows short presses to be detected, for example. A Zigbee device may be requested to repeatedly transmit a short message in order to obtain more RF signals. It is beneficial to select a Zigbee device with mains supply in order not to drain any battery supply. The rate at which the messages are transmitted may be increased upon detecting a first touch to check for long touch and double touch actions.

The rate at which the messages are transmitted may optionally be determined in dependence on whether a user is detected within a predetermined distance of the lighting device 11. If the rate at which the messages are transmitted is determined per device, this message rate may be determined based on the number of devices transmitting radiofrequency signals which are usable for touch detection. The user touching the lighting device 11 may not only be detected based on changes in the signal strengths of Link Status and RF sensing messages, but also based on changes in signal strengths of other messages being transmitted in the lighting system 10, such as light control or sensor data reporting.

The processor 5 may be configured to distinguish between a first area of a housing of the device being touched and a second area of the housing of the device being touched based on the result of the comparison, e.g. if first area of the housing is closer to the antenna 48 than the second area of the housing. For example, the first area may be the area of the housing covered by the visual indication 49 and the second area may be the area of the housing not covered by the visual indication 49.

The processor 5 may be configured to distinguish between the first area of the housing being touched on one hand and the second area of the housing or no part of the device being touched on the other hand or may be configured to distinguish between the first area of the housing being touched, the second area of the housing being touched, and no part of the device being touched. The lighting device 11 may be configured to give visual feedback on the device when the user touches the lighting device 11.

The user may be allowed to activate and deactivate the touch sensing function (e.g. via a configuration menu in a lighting control app) in order to avoid undesired lighting control triggers (e.g. when picking up a portable light) or because of unreliable RF connectivity causing detection of false positive touch events. Alternatively or additionally, the touch sensing function may only be activated automatically in the commissioning phase of lamps. In this case, the rate at which the wireless messages are transmitted may be increased while the touch sensing function is activated to improve the responsiveness of the system.

In the embodiment of the bridge 1 shown in Fig. 1, the bridge 1 comprises one processor 5. In an alternative embodiment, the bridge 1 comprises multiple processors. The processor 5 of the bridge 1 may be a general-purpose processor, e.g. ARM-based, or an application-specific processor. The processor 5 of the bridge 1 may run a Unix-based operating system for example. The memory 7 may comprise one or more memory units. The memory 7 may comprise one or more hard disks and/or solid-state memory, for example. The memory 7 may be used to store a table of connected lights, for example.

The receiver 3 and the transmitter 4 may use one or more wired and/or wireless communication technologies, e.g. Ethernet and/or Wi-Fi (IEEE 802.11), for communicating with the wireless LAN access point 25, for example. In an alternative embodiment, multiple receivers and/or multiple transmitters are used instead of a single receiver and a single transmitter. In the embodiment shown in Fig. 1, a separate receiver and a separate transmitter are used. In an alternative embodiment, the receiver 3 and the transmitter 4 are combined into a transceiver. The bridge 1 may comprise other components typical for a network device such as a power connector. The invention may be implemented using a computer program running on one or more processors.

Fig. 2 shows a second embodiment of the system for detecting a user touching a device. In the second embodiment of Fig. 2, the system is a system 40 which comprises only a lighting device 41. The lighting device 41 detects whether a user is touching lighting device 41. A bridge 27 communicates with lighting devices 41,12-13, e.g. using Zigbee technology. The bridge 27 is connected to the wireless LAN access point 25, e.g. via Ethernet or Wi-Fi.

The lighting device 41 comprises a housing 42, a LED module 43, and an antenna 48. The LED module comprises a plurality of LEDs (not shown in Fig. 2), a processor 45, a transceiver 46, and a memory 47. The processor 45 is configured to obtain signal strengths of one or more received radiofrequency signals via the transceiver 46. The one or more radiofrequency signals are received or transmitted by the lighting device 41 via the antenna 48 comprised in the lighting device 41. The one or more radiofrequency signals may comprise RF signals received by the lighting device 41 from the bridge 27 and/or RF signals received by the lighting device 41 from the lighting devices 12 and 13 and/or RF signals transmitted by the lighting device 41 to the bridge 27 and/or RF signals transmitted by the lighting device 41 to the lighting devices 12 and 13, for example.

The processor 45 is further configured to detect current temporary distortions of the one or more received radiofrequency signals based on the obtained signal characteristics and detect whether the user is touching the lighting device 41 based on a result of the detection.

Since the antenna 48 of the lighting device 41 extends to the inside or the outside of a surface of the lighting device 41, the user touching the lighting device 41 near the spot at which the antenna 48 extends to the inside or the outside of the surface causes a change in RF signal characteristics, e.g. reduction in signal strengths, of the one or more radiofrequency signals received or transmitted by the lighting device 41 via the antenna 48. This makes it possible for the lighting device 41 to detect whether the user is touching the lighting device 41 based on changes in RF signal characteristics, e.g. signal strengths.

If the one or more radiofrequency signals comprise RF signals transmitted by the lighting device 41, the characteristics of these RF signals may be reported to the lighting device 41 by the bridge 27 and/or by the lighting devices 12 and 13. The antenna 48 may be exposed at the surface of the lighting device 41 or covered by a conductive finishing on the surface of the lighting device 41 or mounted directly below the housing 42 of the lighting device. In the embodiment of Fig. 2, a visual indication 49 is provided on the outside of a surface of the lighting device 41. The visual indication 49 indicates where the user should touch the lighting device 41. The lighting device 41 may be configured to give visual feedback on the device when the user touches the lighting device 41.

In the embodiment of the lighting device 41 shown in Fig. 2, the lighting device 41 comprises one processor 45. In an alternative embodiment, the lighting device 41 comprises multiple processors. The processor 45 of the lighting device 41 may be a general- purpose processor, e.g. ARM-based, or an application-specific processor. The transceiver 46 may use one or more wireless communication technologies, e.g. Zigbee, for communicating with the bridge 27, for example.

In the embodiment of Fig. 2, a receiver and a transmitter have been combined into a transceiver. In an alternative embodiment, the receiver and the transmitter may be separate components. In the embodiment of Fig. 2, the lighting device 41 comprises a single transceiver. In an alternative embodiment, the lighting device 41 comprises multiple transceivers. The lighting device 41 may comprise other components typical for a connected lighting device such as a power connector and/or a battery. The invention may be implemented using a computer program running on one or more processors.

In the embodiment of Fig. 2, lighting devices 41,12-13 can be controlled by the mobile device 21 via the bridge 27. In an alternative embodiment, one or more of the lighting devices 41,12-13 can be controlled by the mobile device 21 without a bridge, e.g. directly via Bluetooth or via a cloud server.

An advantage of the embodiment of Fig. 2 over the embodiment of Fig. 1 is that there is a shorter delay between the user touching the lighting device and the light being adjusted, as the lighting device performs the processing/detection itself. In the embodiment of Fig. 1, after the bridge has performed the processing/detection, it still has to transmit a control message to the lighting device. If the lighting device gives visual feedback on the device when the user touches the device, there is also a shorter delay between the user touching the lighting device and the visual feedback.

Fig. 3 and Fig. 4 show a third and a fourth embodiment of the device, respectively. Typically, if the device is a lighting device, the RF transceiver and its antenna will be integrated as part of the device’s light module. However, a touch sensor position close to the module may not always be the best position. In the lighting devices 61 and 71, the antenna 48 is moved or extended towards a different part of the lighting device (different than the lampshade), where it is brought forward towards the surface.

This may enable a more suitable touch sensor position while on the same hand improving the RF signal quality by increasing the dimensions of the antenna. In turn, this improved RF signal quality will improve the touch sensing reliability. In the lighting device 61 of Fig. 3, the antenna 48 is moved or extended towards the lamp body. In the lighting device 71 of Fig. 4, the antenna 48 is moved or extended towards the lamp base. In a more advanced solution, the lighting device could have multiple or longer antenna segments to enable multiple touch buttons (e.g. each representing a light setting) or a touch slider.

While Figs. 1-4 show examples in which the device is a table lamp, Fig. 5 shows an example in which the device is a light bulb 81. The antenna (not shown in Fig. 5) is extended towards the inside or the outside of the surface of the light bulb in the part of the bulb 81 that does not emit light and that is not inserted into a socket. The visual indication 49 indicates where the user should touch the light bulb 81.

In an alternative embodiment, the touch area is in the area that emits light. For example, a GU10, MR16, or PAR36 light bulb may have the antenna under the light exit window. In the case of a light bulb, the touch sensing function may be used during the installation or configuration process, because at that moment the user is nearby and touching the light bulb already anyway.

If a luminaire comprises multiple RF light bulbs close to each other, e.g. multiple light bulbs 81, the system may detect the user touching the luminaire based on RF signals received or transmitted by any of the light bulbs or based on RF signals received or transmitted by a selected one of the light bulbs. As an example of the latter, the light bulb whose transmitted or received RF signal(s) experienced the largest change in signal strength may be selected. In the embodiments of Figs. 1-5, the system detects whether a user is touching a lighting device. In an alternative embodiment, the system detects whether a user is touching a different kind of device, e.g. a smart speaker.

A first embodiment of the method of detecting a user touching a device is shown in Fig. 6. The device may be a lighting device, for example. The method may be performed by the system 10 of Fig. 1 or the system 40 of Fig. 2, for example.

A step 101 comprises obtaining signal characteristics, e.g. signal strengths, of one or more received radiofrequency signals. The one or more radiofrequency signals are received or transmitted by the device via an antenna comprised in the device. The one or more radiofrequency signals may comprise, for example, multiple radiofrequency signals transmitted such that an average duration of intervals between consecutive ones of the multiple radiofrequency signals is at most one second.

A step 102 comprises detecting current temporary distortions of the one or more received radiofrequency signals based on the signal characteristics obtained in step 101. Step 102 may, for example, comprise steps 103 and 105. Step 103 comprises comparing the signal characteristics of the one or more received radiofrequency signals, as obtained in step 101, with stored characteristics of temporary distortions. Step 105 comprises detecting the current temporary distortions based on a result of the comparison of step 103. Alternatively, step 102 may comprise performing anomaly detection

A step 107 comprises detecting whether the user is touching the device based on a result of the detection of step 102. For example, a touch action may be detected if the comparison shows an instant 20-35% drop in signal strength. Additionally, one or more steps of one or more of the embodiments of Figs. 7-10 may be added to the embodiment of Fig. 6.

A second embodiment of the method of detecting a user touching a device is shown in Fig. 7. The embodiment of Fig. 7 is an extension of the embodiment of Fig. 6. In the embodiment of Fig. 7, step 107 of Fig. 6 comprises a step 121 and steps 122 and 123 are performed after step 107.

Step 121 comprises distinguishing between a first area of a housing of the device being touched and a second area of the housing of the device being touched based on the result of the comparison of step 105. Step 121 may comprise distinguishing between the first area of the housing being touched on one hand and the second area of the housing or no part of the device being touched on the other hand or distinguishing between the first area of the housing being touched, the second area of the housing being touched, and no part of the device being touched. Step 122 comprises determining whether the user was detected to be touching the device in step 107. If not, step 101 is repeated, and the method then proceeds as shown in Fig. 7. Step 123 is performed if the user was detected to be touching the device in step 107. Step 123 comprises performing a control action. Step 101 is repeated after step 123, and the method then proceeds as shown in Fig. 7. Additionally, one or more steps of one or more of the embodiments of Figs. 8-10 may be added to the embodiment of Fig. 7.

A third embodiment of the method of detecting a user touching a device is shown in Fig. 8. The embodiment of Fig. 8 is an extension of the embodiment of Fig. 6. In the embodiment of Fig. 8, steps 122, 131, 133, 135, and 123 are performed after step 107 of Fig. 6.

Step 122 comprises determining whether the user was detected to be touching the device in step 107. If not, step 101 is repeated, and the method then proceeds as shown in Fig. 8. Step 131 is performed if the user was detected to be touching the device in step 107. Step 131 comprises determining a duration of a touch action and/or a quantity of touch actions based on characteristics of the current temporary distortions detected in step 102.

Step 133 comprises distinguishing between the different kinds of touch actions based on the duration of the touch action and/or the quantity of touch actions determined in step 131. For example, step 133 may comprise distinguishing between a short tap (e.g. 200- 500ms), a long tap (e.g. 500-1800ms), and a double tap (e.g. two signal drops in 800ms).

Step 135 comprises selecting a control action from a plurality of control actions based on the kind of touch action identified in step 133. Step 123 comprises performing the control action selected in step 135. Step 101 is repeated after step 123, and the method then proceeds as shown in Fig. 8. Additionally, one or more steps of one or more of the embodiments of Figs. 7, 9-10 may be added to the embodiment of Fig. 8.

A fourth embodiment of the method of detecting a user touching a device is shown in Fig. 9. The method may be performed by the system 10 of Fig. 1 or the system 40 of Fig. 2, for example. The method of Fig. 9 may be used to finetune or calibrate the exact touch sensing settings to environmental and user characteristics.

A step 151 comprises asking the user or a different user to touch the device in a designated area (e.g. indicated by a visual marking) in a certain period, e.g. via an app on the user’s mobile device. A step 153 comprises obtaining signal characteristics of one or more received reference radiofrequency signals. The one or more reference radiofrequency signals are received or transmitted by the device via an antenna comprised in the device in the certain period. A step 155 comprises storing the characteristics of the one or more received reference radiofrequency signals, as obtained in step 153, in a memory, as stored characteristics of temporary distortions. Steps 151-155 may be performed multiple times.

Step 101 comprises obtaining signal characteristics of one or more received radiofrequency signals. The one or more radiofrequency signals are received or transmitted by the device via the antenna comprised in the device.

Step 102 comprises detecting current temporary distortions of the one or more received radiofrequency signals based on the signal characteristics obtained in step 101. Step 102 comprises steps 103 and 105. Step 103 comprises comparing the signal characteristics of the one or more received radiofrequency signals, as obtained in step 101, with the characteristics of temporary distortions stored in step 155. Step 103 also comprises retrieving the stored characteristics of temporary distortions from the memory before performing the comparison. Step 105 comprises detecting the current temporary distortions based on a result of the comparison of step 103.

Step 107 comprises detecting whether the user is touching the device based on a result of the detection of step 105. Additionally, one or more steps of one or more of the embodiments of Figs. 7-8,10 may be added to the embodiment of Fig. 9. Step 101 is repeated after step 107, and the method then proceeds as shown in Fig. 9. If multiple users are asked finetune or calibrate the exact touch sensing settings in this way, the system could learn to differentiate between touches of different users, e.g. to render personalized light effects based on who is touching the device. Multiple users may also be asked finetune or calibrate the exact touch sensing settings in this way even if there is no need to differentiate between touches of different users, e.g. in order to render the same light effect whenever any of these users touches the device.

The method of Fig. 9 may be performed when the user commissions the device or the system. In this case, an app could ask the user to touch the device several times in different manners to train it and map specific actions to different touches. The method of Fig. 9 may be extended to train the system when a user intentionally touches the device or accidentally touches the device or carries the device (e.g. a Hue Go lamp) to a different location. For example, the user or the different user may be asked to briefly touch the device with another body part than a fingertip, or to carry the device, and the system may then set or finetune one or more thresholds based on the determined changes in signal characteristics, e.g. signal strengths.

A fifth embodiment of the method of detecting a user touching a device is shown in Fig. 10. The embodiment of Fig. 10 is an extension of the embodiment of Fig. 6. In the embodiment of Fig. 10, steps 122, 171, 173, 175, and 123 are performed after step 107. Step 122 comprises determining whether the user was detected to be touching the device in step 107. If not, step 101 is repeated, and the method then proceeds as shown in Fig. 10. Step 171 is performed if the user was detected to be touching the device in step 107.

Step 171 comprises identifying the user. The user may be identified based on information collected while one or more of steps 101 to 107 were performed. Presence of the user may be detected before the user has tapped the device, e.g. by using RF sensing. Users may be identified based on their (e.g. Bluetooth) personal device identifiers. The identifier of the personal device that is closest to the device may be used as identifier of the user or may be used to lookup the identifier of the user, for example.

Step 173 comprises obtaining a user profile associated with the user identified in step 171. Step 175 comprises selecting a control action based on the user profile obtained in step 173. Step 123 comprises performing the control action selected in step 175. Additionally, one or more steps of one or more of the embodiments of Figs. 7-9 may be added to the embodiment of Fig. 10. Step 101 is repeated after step 123, and the method then proceeds as shown in Fig. 10.

Fig. 11 depicts a block diagram illustrating an exemplary data processing system that may perform the method as described with reference to Figs. 6 to 10.

As shown in Fig. 11, the data processing system 300 may include at least one processor 302 coupled to memory elements 304 through a system bus 306. As such, the data processing system may store program code within memory elements 304. Further, the processor 302 may execute the program code accessed from the memory elements 304 via a system bus 306. In one aspect, the data processing system may be implemented as a computer that is suitable for storing and/or executing program code. It should be appreciated, however, that the data processing system 300 may be implemented in the form of any system including a processor and a memory that is capable of performing the functions described within this specification.

The memory elements 304 may include one or more physical memory devices such as, for example, local memory 308 and one or more bulk storage devices 310. The local memory may refer to random access memory or other non-persistent memory device(s) generally used during actual execution of the program code. A bulk storage device may be implemented as a hard drive or other persistent data storage device. The processing system 300 may also include one or more cache memories (not shown) that provide temporary storage of at least some program code in order to reduce the quantity of times program code must be retrieved from the bulk storage device 310 during execution. The processing system 300 may also be able to use memory elements of another processing system, e.g. if the processing system 300 is part of a cloud-computing platform.

Input/output (I/O) devices depicted as an input device 312 and an output device 314 optionally can be coupled to the data processing system. Examples of input devices may include, but are not limited to, a keyboard, a pointing device such as a mouse, a microphone (e.g., for voice and/or speech recognition), or the like. Examples of output devices may include, but are not limited to, a monitor or a display, speakers, or the like. Input and/or output devices may be coupled to the data processing system either directly or through intervening I/O controllers.

In an embodiment, the input and the output devices may be implemented as a combined input/output device (illustrated in Fig. 11 with a dashed line surrounding the input device 312 and the output device 314). An example of such a combined device is a touch sensitive display, also sometimes referred to as a “touch screen display” or simply “touch screen”. In such an embodiment, input to the device may be provided by a movement of a physical object, such as e.g. a stylus or a finger of a user, on or near the touch screen display.

A network adapter 316 may also be coupled to the data processing system to enable it to become coupled to other systems, computer systems, remote network devices, and/or remote storage devices through intervening private or public networks. The network adapter may comprise a data receiver for receiving data that is transmitted by said systems, devices and/or networks to the data processing system 300, and a data transmitter for transmitting data from the data processing system 300 to said systems, devices and/or networks. Modems, cable modems, and Ethernet cards are examples of different types of network adapter that may be used with the data processing system 300.

As pictured in Fig. 11, the memory elements 304 may store an application 318. In various embodiments, the application 318 may be stored in the local memory 308, the one or more bulk storage devices 310, or separate from the local memory and the bulk storage devices. It should be appreciated that the data processing system 300 may further execute an operating system (not shown in Fig. 11) that can facilitate execution of the application 318. The application 318, being implemented in the form of executable program code, can be executed by the data processing system 300, e.g., by the processor 302. Responsive to executing the application, the data processing system 300 may be configured to perform one or more operations or method steps described herein. Various embodiments of the invention may be implemented as a program product for use with a computer system, where the program(s) of the program product define functions of the embodiments (including the methods described herein). In one embodiment, the program(s) can be contained on a variety of non-transitory computer-readable storage media, where, as used herein, the expression “non-transitory computer readable storage media” comprises all computer-readable media, with the sole exception being a transitory, propagating signal. In another embodiment, the program(s) can be contained on a variety of transitory computer-readable storage media. Illustrative computer-readable storage media include, but are not limited to: (i) non-writable storage media (e.g., read-only memory devices within a computer such as CD-ROM disks readable by a CD-ROM drive, ROM chips or any type of solid-state non-volatile semiconductor memory) on which information is permanently stored; and (ii) writable storage media (e.g., flash memory, floppy disks within a diskette drive or hard-disk drive or any type of solid-state random-access semiconductor memory) on which alterable information is stored. The computer program may be run on the processor 302 described herein.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of embodiments of the present invention has been presented for purposes of illustration, but is not intended to be exhaustive or limited to the implementations in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the present invention. The embodiments were chosen and described in order to best explain the principles and some practical applications of the present invention, and to enable others of ordinary skill in the art to understand the present invention for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

CLAIMS:

1. A system (10,40) for detecting a user touching a device (11,41,61,71,81), wherein said device (11,41,61,71,81) is a lighting device, said system (10,40) comprising: at least one receiver (3,46); and at least one processor (5,45) configured to:

- obtain signal characteristics of one or more received radiofrequency signals via said at least one receiver (3,46), said one or more radiofrequency signals being received or transmitted by said device (11,41,61,71,81) via an antenna (48) comprised in said device (11,41,61,71,81), - detect current temporary distortions of said one or more received radiofrequency signals based on said obtained signal characteristics,

- detect whether said user is touching said device (11,41,61,71,81) based on a result of said detection,

- control said device according to said control action upon detecting said user touching said device (11,41,61,71,81).

2. A system (10,40) as claimed in claim 1, wherein said system (10,40) comprises said device (11,41,61,71,81).

3. A system (10,40) as claimed in claim 2, wherein a visual indication (49) is provided on the outside of a surface of said device (11,41,61,71,81), said visual indication (49) indicating where said user should touch said device (11,41,61,71,81).

4. A system (10,40) as claimed in claim 2 or 3, wherein said antenna (48) of said device (11,41,61,71,81) extends to the inside or the outside of a surface of the housing of said device (11,41,61,71,81).

5. A system (10,40) as claimed in claim 4, wherein said antenna (48) of said device (11,41,61,71,81) is exposed at said surface of said device (11,41,61,71,81) or covered by a conductive finishing on said surface of said device (11,41,61,71,81) or mounted directly below a housing of said device (11,41,61,71,81).

6. A system (10,40) as claimed in any one of the preceding claims, wherein said at least one processor (5,45) is configured to:

- determine a duration of a touch action and/or a quantity of touch actions based on characteristics of said current temporary distortions, and

- distinguish between different kinds of touch actions based on said duration of said touch action and/or said quantity of touch actions.

7. A system (10,40) as claimed in any one of the preceding claims, wherein said at least one processor (5,45) is configured to:

- compare said signal characteristics of said one or more received radiofrequency signals with stored characteristics of temporary distortions, and

- detect said current temporary distortions based on a result of said comparison.

8. A system (10,40) as claimed in claim 7, wherein said at least one processor (5,45) is configured to distinguish between a first area of a housing of said device

(11,41,61,71,81) being touched and a second area of said housing of said device

(11,41,61,71,81) being touched based on said result of said comparison, said first area of said housing being closer to said antenna (48) of said device (11,41,61,71,81) than said second area of said housing.

9. A system (10,40) as claimed in claim 7 or 8, wherein said at least one processor (5,45) is configured to:

- ask said user or a different user to touch said device (11,41,61,71,81) in a designated area in a certain period, - obtain signal characteristics of one or more received reference radiofrequency signals via said at least one receiver (3,46), said one or more reference radiofrequency signals being received or transmitted by said device (11,41,61,71,81) via said antenna (48) in said certain period,

- store said characteristics of said one or more received reference radiofrequency signals in a memory (7,47) as said stored characteristics of temporary distortions,

- compare said characteristics of said one or more received radiofrequency signals with said stored characteristics of temporary distortions, and

10. A system (10,40) as claimed in any one of the preceding claims, wherein said one or more radiofrequency signals comprise multiple radiofrequency signals, an average duration of intervals between consecutive ones of said multiple radiofrequency signals being at most one second.

11. A system (10,40) as claimed in any one of the preceding claims, wherein said at least one processor (5,45) is configured to:

- identify said user,

- obtain a user profile associated with said user,

- select said control action further based on said user profile, and

- perform said control action upon detecting said user touching said device (11,41,61,71,81).

12. A method of detecting a user touching a device, wherein said device is a lighting device, said method comprising:

- obtaining (101) signal characteristics of one or more received radiofrequency signals, said one or more radiofrequency signals being received or transmitted by said device via an antenna comprised in said device,

- detecting (102) current temporary distortions of said one or more received radiofrequency signals based on said obtained signal characteristics,

- detecting (107) whether said user is touching said device based on a result of said detection, - determining a duration of a touch action and/or a quantity of touch actions based on characteristics of the current temporary distortions,

- identifying a kind of touch action based on the duration of the touch action and/or the quantity of touch actions determined, - selecting a control action from a plurality of control actions based on the kind of touch action, and

13. A computer program product for a computing device, the computer program product comprising computer program code to perform the method of claim 12 when the computer program product is run on a processing unit of the computing device.