Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B47/00—Circuit arrangements for operating light sources in general, i.e. where the type of light source is not relevant
  • H05B47/10—Controlling the light source
  • H05B47/105—Controlling the light source in response to determined parameters
  • H05B47/115—Controlling the light source in response to determined parameters by determining the presence or movement of objects or living beings
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
  • G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
  • G01S15/04—Systems determining presence of a target
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B47/00—Circuit arrangements for operating light sources in general, i.e. where the type of light source is not relevant
  • H05B47/10—Controlling the light source
  • H05B47/105—Controlling the light source in response to determined parameters
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B47/00—Circuit arrangements for operating light sources in general, i.e. where the type of light source is not relevant
  • H05B47/10—Controlling the light source
  • H05B47/175—Controlling the light source by remote control
  • H05B47/19—Controlling the light source by remote control via wireless transmission
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S15/00—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems
  • G01S15/02—Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems using reflection of acoustic waves
  • G01S15/50—Systems of measurement, based on relative movement of the target
  • G01S15/52—Discriminating between fixed and moving objects or between objects moving at different speeds
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
  • Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection

Definitions

• the present invention generally relates to the field of control systems, and in particular to a control system comprising a first active sensor and a second active sensor and methods corresponding thereto.
• Office lighting constitutes almost 30% of the electrical consumption in buildings.
• LED light-emitting-diode
• they are becoming viable alternatives for fluorescent lamps, further offering the advantage of color control.
• lighting control strategies based on occupant presence information are very effective in reducing energy consumption. For example, in unoccupied areas the illumination may be dimmed or extinguished.
• the design of green buildings may benefit from presence-adaptive lighting control systems.
• active sensors such as ultrasound based sensors
• passive infrared sensors provide better detection than passive infrared sensors in large volumetric spaces.
• active sensors are more sensitive than passive infrared sensors generally.
• An ultrasonic array sensor has been described in WO 2005/069698 for reliable presence sensing that, when interfaced with a lighting control system, provides reliable illumination rendering.
• a light source illuminates a local area with light that is modulated to identify the local area.
• a wearable occupancy detector located in the local area radiates a signal identifying the local area.
• the radiated signal is received by a control unit that is in communication with the light source and is capable of controlling a lighting function of the light source. Occupancy detection in accordance with WO 2005/069698 does not depend on motion.
• a control system comprising a first active sensor comprising a transmitter arranged to transmit a first probe signal; and a second active sensor comprising a transmitter arranged to transmit a second probe signal, and a receiver sensor array arranged to receive the first probe signal and an echo of the second probe signal; wherein the first probe signal is possibly different from the second probe signal such that interference at the receiving sensor array between the first probe signal and the second probe signal is avoided.
• the disclosed system may thus advantageously be used in situations wherein users employ devices comprising the first active sensor to assist a fixed infrastructure comprising the second active sensor to determine locations of the user.
• the disclosed first active sensor needs only to be capable of transmitting a signal (and hence not to receive any signals).
• the disclosed first active sensor does not even need to be synchronized with the fixed infrastructure. Since the signal of the local device is distinct from the fixed infrastructure as represented by the second active sensor.
• control system further comprises a light source and a processing unit, wherein the processing unit is arranged to predictively estimate a location of the first active sensor based on the received first probe signal, and to control a lighting function of the light source in accordance with the predictively estimated location of the first active sensor.
• the control system thereby enables improved lighting control functionalities.
• the first active sensor can be localized by using a direction of arrival algorithm.
• the first probe signal originating from the first active sensor may be detected by correlation.
• the signal transmitted by the local device is an in band signal. This requires no adaptation of the receiver sensor array. Alternatively the signal can be sent out of band. This may allow for a cheaper transmitter of the first active sensor.
• an out of band transmission could require a wideband receiver sensor array in the second sensor, one advantage of out of band signaling is avoiding interference with the signal sent from the second active sensor.
• the first active sensor further comprises a receiver.
• the first probe signal is then preferably transmitted in response to reception of the second probe signal by the receiver.
• the control system may be synchronized.
• a receiver element in the first sensor provides a better accuracy in the localization. If the first sensor does not have a receiver element, an estimation of the location of the occupant can only be obtained based on angular information.
• the first active sensor comprises an array of receiver elements. Thereby improved localization of the first active sensor may be achieved.
• the synchronization is preferably performed with respect to the signal coming from a predefined angle, i.e. corresponding to the second sensor.
• the objective is achieved by a method in a control system comprising a first active sensor and a second active sensor, comprising transmitting, by a transmitter of the first active sensor, a first probe signal;
• Fig. 1 illustrates a control system according to embodiments
• Figs. 2-7 schematically illustrate waveforms of probe signals according to embodiments.
• Fig. 8 is a flowchart of a method according to embodiments.
• Embodiments of the present invention may be applied to improvements of localized lighting rendering in a location with a fixed sensor infrastructure.
• portable sensor devices one of which below is referred to as a first active sensor
• WO2005/069698 describes a wearable occupancy detector that is based on the use of a uniquely-modulated signal (e.g., radio frequent (RF), infrared (IR) or visible light), which is used to indicate presence in certain local areas so that the certain local areas can be appropriately illuminated.
• RF radio frequent
• IR infrared
• visible light e.g., visible light
• a light source illuminates a local area with light that is modulated to identify the local area.
• a wearable occupancy detector located in the local area radiates a signal identifying the local area.
• the wearable detectors are reactive, i.e. they transmit only after receiving a signal from the light sources.
• embodiments of the present invention are based on a system already comprising an infrastructure ultrasonic array sensor that performs presence detection.
• a portable sensor system that can coexist with the infrastructure sensor, thereby realizing new control functionalities.
• the portable sensor system is independent from the infrastructure sensor in the sense that it is not activated or otherwise controlled by the infrastructure sensor, as is the case in WO2005/069698.
• Embodiments of the present invention will be disclosed with respect to an ultrasonic sensor modality, although the embodiments may likewise be applied to other active sensors, such as radars. It is further assumed that an ultrasound array sensor (referred below to as a second active sensor) is fixed in the lighting infrastructure of a room. However, as the skilled person understands, the ultrasound array sensor may be separated from the lighting infrastructure.
• Fig. 1 schematically illustrates a control system 1 according to the present invention.
• the control system 1 is according to the schematic example of Fig. 1 placed in a room 10.
• the room 10 is a room of a building.
• the control system 1 comprises a first active sensor 2 and a second active sensor 3.
• the first active sensor 2 is preferably a portable sensor.
• the second active sensor 3 is preferably a fixed infrastructure sensor.
• the first active sensor 2 comprises a transmitter 4 and optionally a receiver 5.
• the second active sensor 3 comprises a transmitter 6, a receiver 7 and optionally a processing unit 8.
• the control system 1 may further comprise at least one light source 9.
• the second active sensor 3 and at least one of the at least one light sources 9 are part of the same device, for example a luminaire.
• the light source 9 may be said to comprise the second active sensor 3.
• the transmitter 6 of the second active sensor 3 is, in a step S04, arranged to transmit a second probe signal 11a as represented by the waveform illustrated in Fig. 2 over an area defined by the directivity of the transmitter 6.
• the parameter T defines a length over which the waveform is non-zero in each pulse repetition interval (PRI) and is chosen as per the spatial resolution required.
• the PRI is chosen to accommodate the largest expected range in time before an echo l ib of the transmitted second probe signal 11a is expected to be received by the receiver 7.
• the receiver 7 of the second active sensor 3 is preferably a receiver sensor array and thus preferably comprises one or more receiver elements in an array.
• received signals are processed in order to determine presence sensing information.
• an echo 1 lb of the second probe signal 1 la is received by the receiver 7, step S06.
• a difference signal is obtained by taking the difference of echo signals corresponding to two PRIs.
• a static object results in a corresponding (almost) zero difference signal component at the related time-of-flight, whereas a moving object results in a non-zero signal component at the related time-of-flight.
• the power in the difference signal at different time-of-flight windows can thus be used to, by means of the second probe signal 11a and its echo l ib, detect human presence in the room 10.
• the transmitter 4 of the first active sensor 2 is arranged to transmit a first probe signal 12, step S02.
• the first active sensor 2 is carried by a user.
• the transmitter 4 of the first active sensor 2 is activated, for example by means of receiving user input from the user, to transmit the first probe signal 12.
• the first probe signal 12 is received by the receiver 7 of the second active sensor 3, step S06.
• the waveform of the first probe signal 12 is preferably different from the waveform of the second probe signal 11a such that interference at the receiving sensor array between the first probe signal 11 and the second probe signal 12a is avoided, or at least minimized. This will be further disclosed below with references to Figs. 5-7.
• Fig. 3 schematically illustrates received (echoes of) probe signals at a particular receiver element of the receiver 7.
• the received signals correspond to echoes l ib of two transmitted second probe signals 11a transmitted by the second active sensor 3 and one transmission of a first probe signal 12 transmitted by the first active sensor 2.
• the solid and dashed waveforms in Fig. 3 correspond to echoes from a moving and a static source, respectively, and the dotted waveform corresponds to the received first probe signal transmitted by the transmitter 4 of the first active sensor 2.
• the signal received at the second active sensor 3 and which originates from the first active sensor 2 is not an echo from the first active sensor 2 but a direct transmission from the first active sensor 2 to the second active sensor 3.
• the waveform of the first probe signal 12 from the first active sensor 3 is preferably chosen to be uncorrected to the waveform of the second probe signal 11a (and the echo l ib thereof) transmitted by the second active sensor 3.
• the first probe signal 12 preferably comprises only a single waveform burst.
• the first probe signal 12 advantageously comprises only a single waveform burst in order to avoid the elimination of the first probe signal 12 during signal processing at the receiver 7, for example when determining a difference between pulses in two consecutive PRIs.
• This process is illustrated in Fig. 5.
• a second probe signal (solid lines) is in the first and second PRIs transmitted by the transmitter 6 of the second active sensor 3.
• echoes of the second probe signal are in the first and second PRIs received by the receiver 7 of the second active sensor 3 at time ⁇ 1 after transmission of the same.
• a first probe signal (dotted lines) is transmitted by the first active sensor 2.
• the first probe signal is received by the second active sensor 3 at time ⁇ 2 after transmission of the same.
• the first probe signal 12 is received at the receiver 7 at an arbitrary time delay from its transmission by the transmitter 4.
• the time delay ⁇ 2 is, in the most general case, unknown at the receiver 7 because the first active sensor 2 and the second active sensor 3 are not necessarily synchronized.
• the difference between the collected signals received in the first and the second PRIs is taken and since there is only one version of the first probe signal (where the first probe signal is preferably different from the second probe signal), the first probe signal is not affected by the subtraction (or at least it is not fully eliminated).
• Subtraction preferably involves time shift and/or scaling of the signal in the two PRIs.
• the control system 1 would be sufficiently robust if the first active sensor 2 transmits the first probe signal 12 more than once.
• the first probe signal 12 can be transmitted every n:th PRI, where n > 2.
• the first probe signal 12 is preferably not transmitted in every second PRI, because the first probe signal 12 would then be eliminated when the difference is obtained at the receiver 7.
• the (transmitter 4 of the) first active sensor 2 may be arranged to transmit at most one first probe signal 12 for every three transmissions of the second probe signal 11a.
• the first probe signal 12 is an in-band transmitted signal with respect to the receiver 7 of the second active sensor 3.
• An in-band transmitted waveform refers to a waveform with centre frequency within the bandwidth of the receiver 7.
• the first probe signal 12 is an out-of-band signal with respect to the receiver 7 of the second active sensor 3.
• Such an out-of-band signal may inter alia be transmitted at acoustic frequencies or other ultrasonic frequencies within the bandwidth of the receiver 7. It is possible to use such an out-of-band signal given the wideband frequency response of the receiver elements of the second active sensor 3. If the received power exceeds a pre-defined threshold upon correlation at the designated frequencies of transmission, then the direction-of-arrival (see below) is determined based on which localization is achieved.
• control system 1 may further comprise a processing unit 8 which preferably is part of the second active sensor 3.
• the processing unit 8 is preferably arranged to predictively estimate a location of the first active sensor 2 based on the received first probe signal 12.
• a version of the first probe signal 12 may be accessible by the second active sensor 3. For example, a local copy of the waveform transmitted by the first active sensor 2 is maintained and correlated with the received signal. If the first active sensor 2 is to be uniquely determined, then a pre-configuration step may be required where a specific waveform is associated with the first active sensor 2 and a local copy thereof is stored at the second active sensor 3.
• the local copy preferably is an exact copy of the first probe signal 12. If unique identification of the first active sensor 2 is not required, then a general predefined waveform (preferably still different from the waveform of the second probe signal 11a as transmitted by the second active sensor 3, but not unique with respect to different first active sensors) can be used which has been previously store in (or being accessible by) the second active sensor 3 (inter alia via programming or commissioning). If the differential signal at the second active sensor 3 is correlated with the local copy of the waveform from the first active sensor 2, then at (vii) a high correlation would be observed at the instant when the direct first probe signal is received by the second active sensor 3. If the correlation is higher than a threshold 'C then it may be determined that a signal equal to the local waveform was received at that instant of time.
• a threshold 'C it may be determined that a signal equal to the local waveform was received at that instant of time.
• the phase differences of the signals at different receiver elements of the receiver 7 may be used to determine the direction-of-arrival (DoA) based on which the first active sensor 2 (equivalently, the user of the first active sensor 2) is localized.
• DoA direction-of-arrival
• the DoA may be compared with a DoA that is determined (inter alia based on reflections due to the user of the) first active sensor 2 using the received signals at the second active sensor 3 based on which even the range of the user with respect to the second active sensor 3 may be determined.
• Signal components excepting the correlated signal component may be used to determine presence and enhanced presence information as described in WO2005/069698.
• the processing unit 8 may then, based on the estimated location of the first active sensor 2, control a lighting function of the light source 9.
• the lighting function preferably relates to illumination of the location determined for the first active sensor 2.
• the waveform of the first probe signal 12 is different from the waveform of the second probe signal 11a and the echo 1 lb thereof as received by the receiver 7 of the second active sensor 3.
• Fig. 7. illustrates a situation where the waveform of the first probe signal 12 is identical to the waveform of the second probe signal 11a but where the arrival time at the receiver 7 differs.
• the time delay for said one signal in the second PRI is ⁇ 3. Since only one signal is received in the second PRI it may be assumed that no direct transmission is received in the second PRI.
• the time delay •3 may then be used to set the threshold C.
• the threshold C will have a slope.
• the slope generally depends on ⁇ 3.
• the threshold C is thus in fact not a fixed constant but a threshold function.
• the threshold function C is determined, based on ⁇ 3, such that a signal in the first PRI corresponding to the signal received in the second PRI at time delay ⁇ 3 is not identified as a direct transmission.
• the two peaks have the same height but by means of the threshold function C only one peak is identified as being representative of a direct transmission from the first active senor 2. Thereby the direct transmission of the first probe signal 12 can be identified even though both waveform and amplitude are the same as for the second probe signal 11a.
• the transmitted power of the second probe signal 11a is known, then the maximum received power of any echo at a given range can be determined.
• the first probe signal 12 of the first active sensor 2 is only attenuated by distance and the power is the same after the differential processing. It could further be assumed that for a given range, any signal with a power higher than a threshold originates from the first active sensor. This procedure may have a higher rate of misdetection and may require several retransmission from the first active sensor 3 to ensure the detection of the first probe signal 12. Furthermore, it may require a larger transmission power of the transmitter 4 of the first active sensor 3.
• the first active sensor 2 also comprises a receiver
• the first probe signal 12 is then preferably transmitted (in-band or out-of-band) just after the receiver 5 detects the second probe signal 12a transmitted by the second active sensor 3.
• the transmitter 4 of the first active sensor 2 may be arranged to transmit the firs probe signal 11 in response to reception of the second probe signal 12a by the receiver 5.
• the time duration (time-of-flight) for a one-way transmission of a (first and/or second) probe signal between the first active sensor 2 and the second active sensor 3 is ⁇ .
• the first probe signal 12 is then received at the receiver 7 at a time delay, -2 ⁇ , that is related to the distance between the first active sensor 2 and the second active sensor 3, as depicted in Fig 4.
• the location of the portable sensor may then be obtained using the DoA as determined above and the time-of-flight of the signal.
• the receiver 5 of the first active sensor 2 is an array sensor which comprises an array of receiver elements.
• the first active sensor 2 may be arranged to activate its array sensor to a listening mode.
• the received signals at the array sensor obtained due to transmission of second probe signals 11a from the second active sensor 3 may then be used to determine DoA and localization of the first active sensor 2 with respect to the second active sensor 3.
• This information may then be signaled back to a lighting controller.
• the signaling may be done using different modalities, inter alia, infrared red, modulated light emitted by LEDs etc.
• the probe signals have a carrier frequency of approximately 30-50 kHz, preferably 25-45 kHz, even more preferably 40 kHz and a bandwidth of approximately 1-5 kHz, preferably 1-3 kHz, even more preferably 2 kHz.
• a commercial off- the-shelf transmitter with a carrier frequency of 40 kHz having a typical bandwidth of 2 kHz may be used.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Radar, Positioning & Navigation (AREA)
• Remote Sensing (AREA)
• Computer Networks & Wireless Communication (AREA)
• Acoustics & Sound (AREA)
• General Physics & Mathematics (AREA)
• Circuit Arrangement For Electric Light Sources In General (AREA)
• Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
• Radar Systems Or Details Thereof (AREA)
• Arrangements For Transmission Of Measured Signals (AREA)

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• 2013
  • 2013-05-10 ES ES13735415T patent/ES2753074T3/es active Active
  • 2013-05-10 CN CN201380025287.7A patent/CN104303076B/zh active Active
  • 2013-05-10 JP JP2015512174A patent/JP6207595B2/ja active Active
  • 2013-05-10 EP EP13735415.5A patent/EP2850453B1/en active Active
  • 2013-05-10 RU RU2014150541A patent/RU2632248C2/ru active
  • 2013-05-10 WO PCT/IB2013/053802 patent/WO2013171645A2/en not_active Ceased
  • 2013-05-10 US US14/394,879 patent/US9301374B2/en active Active

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