Methods and apparatus for light-based positioning and navigation

Systems, methods, mobile computing devices and computer-readable media are described herein relating to light-based positioning. In various embodiments, light sources (106) may be commissioned to selectively energize one or more LEDs to emit light carrying a coded light signal. The coded light signal may convey information about a location of a lighting effect (102) projected by the one or more LEDs onto a surface (104). In various embodiments, mobile computing devices (100) such as smart phones or tablets may detect these coded light signals from the lighting effects and/or from the light sources, extract the location information, and utilize it to determine their locations within an environment.

TECHNICAL FIELD

The present invention is directed generally to light-based positioning and navigation. More particularly, various inventive methods and apparatus disclosed herein relate to light sources commissioned and configured to emit coded signals carrying information about locations of lighting effects they produce, as well as the use of this information by mobile computing devices to determine a location of a mobile computing device within an environment.

BACKGROUND

Digital lighting technologies, i.e. illumination based on semiconductor light sources, such as light-emitting diodes (LEDs), offer a viable alternative to traditional fluorescent, HID, and incandescent lamps. Functional advantages and benefits of LEDs include high energy conversion and optical efficiency, durability, lower operating costs, and many others. Recent advances in LED technology have provided efficient and robust full-spectrum lighting sources that enable a variety of lighting effects in many applications. Some of the fixtures embodying these sources feature a lighting module, including one or more LEDs capable of producing different colors, e.g. red, green, and blue, as well as a processor for independently controlling the output of the LEDs in order to generate a variety of colors and color-changing lighting effects.

Coded light (CL) systems generally comprise a plurality of lights within each of which is embedded a unique identifier or code. The invisible identifier or code can be embedded in light sources such as LEDs, as well as incandescent, halogen, fluorescent, and high-intensity discharge lamps. The identifier is based on modulation of visible light of the light source or by placing an additional infrared source in or with the light source and modulating that light emitted by this infrared source. LEDs are particularly well-suited for CL systems since they allow for high modulation bandwidth and frequency.

The unique identifier or code emitted by the light source can be utilized by a wide variety of tools and applications, including the identification of one or more specific light sources in the presence of numerous light sources, which in turn enables applications such as lighting manipulation and modification schemes. Further, information about the spatiotemporal location of the identified light source can either be separately associated with the identified light source's identifier, or can be directly embedded into the code transmitted by the coded light source. Coded light systems can be established in any location where a receiver capable of detecting coded light can be used, including but not limited to shopping malls, homes, office buildings, tunnels, subways, parking garages, and other locations.

As urbanization continues, more and larger indoor and/or underground environments will be built for shopping, parking, traffic, living, and so forth. Many such environments may alter, weaken and/or block global positioning system (GPS) signals, making navigation with mobile computing devices such as smart phones difficult. Those same environments may lack natural sunlight, and therefore may be lit with artificial lighting. Technology exists that enables sources of that artificial light to emit locational information that may be used by mobile computing devices for navigational purposes. However, a local network connection (e.g., Wi-Fi) may be required for the mobile computing device to associate a particular light source with a particular location. Further, such systems may not provide sufficient information for a mobile computing device to determine its precise location with sufficient accuracy.

Thus, there is a need in the art for light-based navigation and positioning technology that does not require a mobile computing device to connect to a local (e.g., wireless) network, and that is more accurate than existing approaches.

SUMMARY

The present disclosure is directed to inventive methods and apparatus for light-based positioning. For example, light sources may be configured, e.g., using commissioning computing devices, to emit coded light signals that carry information about a position of lighting effects projected by the light sources. Mobile computing devices such as smart phones and/or tablet computers may utilize this information to determine their locations within an environment.

Generally, in one aspect, the invention relates to a computer-implemented method for calculating a location of a mobile computing device within an environment that includes: receiving, at the mobile computing device, a coded light signal originating from a light source; extracting, by the mobile computing device from the coded light signal, information about a location of a lighting effect projected by the light source onto a surface; determining, by the mobile computing device, an orientation of the mobile computing device relative to the surface; and calculating, by the mobile computing device, the location of the mobile computing device within the environment based at least in part on the location of the lighting effect and the orientation of the mobile computing device.

In various embodiments, the calculating step may include calculating a distance of the mobile computing device from a center of the lighting effect. In various versions, the method may further include calculating, by the mobile computing device, an angle between a first vector extending from a focal point of a camera lens of the mobile computing device to the surface along a central axis of the camera lens, and a second vector extending from the focal point to the center of the lighting effect, wherein calculating the location is further based on the angle. In various versions, calculating the angle may be based at least in part on a distance between a rendition of the lighting effect on a display of the mobile computing device and a center of the display. In various versions, calculating the location may be further based on an estimated reference distance of the mobile device from the surface.

In various embodiments, the calculating step may include calculating a distance of the mobile computing device from the light source. In various versions, the method may further include calculating, by the mobile computing device, an angle between a first vector that is normal to the surface and a second vector that extends from the light source to the mobile computing device. In various versions, calculating the angle may be based at least in part on a distance between a rendition of the light source on a display of the mobile computing device and a center of the display.

In various embodiments, the method may include extracting, by the mobile computing device from the coded light signal, a reference distance of the light source from the surface, wherein calculating the distance of the mobile computing device from the light source is based on the reference distance. In various embodiments, the method may further include determining, by the mobile computing device, an angle between a first vector that extends along the surface from the mobile computing device to a position on the surface opposite the light source, and a second reference vector that is predefined relative to a magnetic pole, wherein calculating the distance of the mobile computing device from the light source is based on the extracted angle.

In another aspect, the invention relates to a light source that includes one or more light-emitting diodes (LEDs); and a controller operably coupled with the one or more LEDs. The controller may be configured to selectively energize the one or more LEDs to emit light carrying a coded light signal, wherein the coded light signal conveys information about a location of a lighting effect projected by the one or more LEDs onto a surface. In various versions, the information about the location of the lighting effect includes a location of a center of the lighting effect.

In various embodiments, the coded light signal may further convey a reference distance between the light source and the surface. In various embodiments, the controller may be further configured to derive the information about the location of the lighting effect based on a direction of a light beam produced by the one or more LEDs.

In various embodiments, the controller may be further configured to derive the information about the location of the lighting effect based on a width of a light beam produced by the one or more LEDs. In various embodiments, a global positioning system (GPS) unit may be operably coupled with the controller, and the controller may be further configured to derive the information about the location of the lighting effect based on data received from the GPS unit and a direction of the emitted light beam.

In another aspect, the invention relates to a computer-implemented method for commissioning a light source, including: placing a commissioning device in a lighting effect projected by the light source onto a surface; determining, by the commissioning device, a location of the commissioning device within an environment; and transmitting, by the commissioning device to the light source, a location of the lighting effect within the environment, wherein the location of the light effect is based at least in part on the determined location of the commissioning device.

In various embodiments, the transmitting may include transmitting a reference distance between the light source and the surface. In various embodiments, the transmitting may include transmitting an angle between a first vector that is normal to the surface and extends from a center of the lighting effect, and a second vector from the commissioning device to the light source. In various versions, the method may further include calculating, by the commissioning device, the angle based at least in part on a distance between a rendition of the lighting effect on a display of the commissioning device and a center of the display.

In various embodiments, the transmitting may include transmitting an angle between a first vector that extends along the surface from a center of the lighting effect to a position on the surface opposite the light source, and a second reference vector that is predefined relative to a magnetic pole. In various embodiments, the method may include calculating, by the mobile computing device, the angle based at least in part on an orientation of the mobile computing device relative to the magnetic pole.

As used herein for purposes of the present disclosure, the term “LED” should be understood to include any electroluminescent diode or other type of carrier injection/junction-based system that is capable of generating radiation in response to an electric signal. Thus, the term LED includes, but is not limited to, various semiconductor-based structures that emit light in response to current, light emitting polymers, organic light emitting diodes (OLEDs), electroluminescent strips, and the like. In particular, the term LED refers to light emitting diodes of all types (including semi-conductor and organic light emitting diodes) that may be configured to generate radiation in one or more of the infrared spectrum, ultraviolet spectrum, and various portions of the visible spectrum (generally including radiation wavelengths from approximately 400 nanometers to approximately 700 nanometers). Some examples of LEDs include, but are not limited to, various types of infrared LEDs, ultraviolet LEDs, red LEDs, blue LEDs, green LEDs, yellow LEDs, amber LEDs, orange LEDs, and white LEDs (discussed further below). It also should be appreciated that LEDs may be configured and/or controlled to generate radiation having various bandwidths (e.g., full widths at half maximum, or FWHM) for a given spectrum (e.g., narrow bandwidth, broad bandwidth), and a variety of dominant wavelengths within a given general color categorization.

For example, one implementation of an LED configured to generate essentially white light (e.g., a white LED) may include a number of dies which respectively emit different spectra of electroluminescence that, in combination, mix to form essentially white light. In another implementation, a white light LED may be associated with a phosphor material that converts electroluminescence having a first spectrum to a different second spectrum. In one example of this implementation, electroluminescence having a relatively short wavelength and narrow bandwidth spectrum “pumps” the phosphor material, which in turn radiates longer wavelength radiation having a somewhat broader spectrum.

It should also be understood that the term LED does not limit the physical and/or electrical package type of an LED. For example, as discussed above, an LED may refer to a single light emitting device having multiple dies that are configured to respectively emit different spectra of radiation (e.g., that may or may not be individually controllable). Also, an LED may be associated with a phosphor that is considered as an integral part of the LED (e.g., some types of white LEDs). In general, the term LED may refer to packaged LEDs, non-packaged LEDs, surface mount LEDs, chip-on-board LEDs, T-package mount LEDs, radial package LEDs, power package LEDs, LEDs including some type of encasement and/or optical element (e.g., a diffusing lens), etc.

The term “light source” should be understood to refer to any one or more of a variety of radiation sources, including, but not limited to, LED-based sources (including one or more LEDs as defined above).

A given light source may be configured to generate electromagnetic radiation within the visible spectrum, outside the visible spectrum, or a combination of both. Hence, the terms “light” and “radiation” are used interchangeably herein. Additionally, a light source may include as an integral component one or more filters (e.g., color filters), lenses, or other optical components. Also, it should be understood that light sources may be configured for a variety of applications, including, but not limited to, indication, display, and/or illumination. An “illumination source” is a light source that is particularly configured to generate radiation having a sufficient intensity to effectively illuminate an interior or exterior space. In this context, “sufficient intensity” refers to sufficient radiant power in the visible spectrum generated in the space or environment (the unit “lumens” often is employed to represent the total light output from a light source in all directions, in terms of radiant power or “luminous flux”) to provide ambient illumination (i.e., light that may be perceived indirectly and that may be, for example, reflected off of one or more of a variety of intervening surfaces before being perceived in whole or in part).

The term “spectrum” should be understood to refer to any one or more frequencies (or wavelengths) of radiation produced by one or more light sources. Accordingly, the term “spectrum” refers to frequencies (or wavelengths) not only in the visible range, but also frequencies (or wavelengths) in the infrared, ultraviolet, and other areas of the overall electromagnetic spectrum. Also, a given spectrum may have a relatively narrow bandwidth (e.g., a FWHM having essentially few frequency or wavelength components) or a relatively wide bandwidth (several frequency or wavelength components having various relative strengths). It should also be appreciated that a given spectrum may be the result of a mixing of two or more other spectra (e.g., mixing radiation respectively emitted from multiple light sources).

The term “lighting fixture” is used herein to refer to an implementation or arrangement of one or more lighting units in a particular form factor, assembly, or package. The term “lighting unit” is used herein to refer to an apparatus including one or more light sources of same or different types. A given lighting unit may have any one of a variety of mounting arrangements for the light source(s), enclosure/housing arrangements and shapes, and/or electrical and mechanical connection configurations. Additionally, a given lighting unit optionally may be associated with (e.g., include, be coupled to and/or packaged together with) various other components (e.g., control circuitry) relating to the operation of the light source(s). An “LED-based lighting unit” refers to a lighting unit that includes one or more LED-based light sources as discussed above, alone or in combination with other non LED-based light sources. A “multi-channel” lighting unit refers to an LED-based or non LED-based lighting unit that includes at least two light sources configured to respectively generate different spectrums of radiation, wherein each different source spectrum may be referred to as a “channel” of the multi-channel lighting unit.

The term “addressable” is used herein to refer to a device (e.g., a light source in general, a lighting unit or fixture, a controller or processor associated with one or more light sources or lighting units, other non-lighting related devices, etc.) that is configured to receive information (e.g., data) intended for multiple devices, including itself, and to selectively respond to particular information intended for it. The term “addressable” often is used in connection with a networked environment (or a “network,” discussed further below), in which multiple devices are coupled together via some communications medium or media.

In one network implementation, one or more devices coupled to a network may serve as a controller for one or more other devices coupled to the network (e.g., in a master/slave relationship). In another implementation, a networked environment may include one or more dedicated controllers that are configured to control one or more of the devices coupled to the network. Generally, multiple devices coupled to the network each may have access to data that is present on the communications medium or media; however, a given device may be “addressable” in that it is configured to selectively exchange data with (i.e., receive data from and/or transmit data to) the network, based, for example, on one or more particular identifiers (e.g., “addresses”) assigned to it.

The term “network” as used herein refers to any interconnection of two or more devices (including controllers or processors) that facilitates the transport of information (e.g. for device control, data storage, data exchange, etc.) between any two or more devices and/or among multiple devices coupled to the network. As should be readily appreciated, various implementations of networks suitable for interconnecting multiple devices may include any of a variety of network topologies and employ any of a variety of communication protocols. Additionally, in various networks according to the present disclosure, any one connection between two devices may represent a dedicated connection between the two systems, or alternatively a non-dedicated connection. In addition to carrying information intended for the two devices, such a non-dedicated connection may carry information not necessarily intended for either of the two devices (e.g., an open network connection). Furthermore, it should be readily appreciated that various networks of devices as discussed herein may employ one or more wireless, wire/cable, and/or fiber optic links to facilitate information transport throughout the network.

DETAILED DESCRIPTION

More and larger indoor and/or underground environments are being built for shopping, parking, traffic, living, and so forth. Many such environments may interfere with or even block GPS signals, making conventional GPS-based navigation with mobile computing devices difficult. Those same environments may lack natural sunlight, and therefore may be lit with artificial lighting. Technology exists that enables sources of that artificial light to emit locational information that may be used by mobile computing devices for positioning and/or navigational purposes. However, a local network connection (e.g., Wi-Fi) may be required for the mobile computing device to associate a particular light source with a particular location, and such systems may not provide sufficient information for a mobile computing device to determine its location with sufficient accuracy.

Accordingly, Applicants have recognized and appreciated that it would be beneficial to utilize lighting infrastructure to facilitate location determination and navigation by mobile computing devices within an enclosed environment, without requiring a network connection by the mobile computing devices. Applicants further recognized and appreciated that it would be beneficial to provide light-based navigation and positioning to facilitate calculation of a mobile computing device's location within an environment with a higher degree of accuracy than has been possible in the past.

In view of the foregoing, various embodiments and implementations of the present invention are directed to light-based navigation and positioning. In various embodiments, light sources may be selectively energized to project lighting effects on surfaces. Those lighting effects may carry coded light signals that convey various types of information about a location of the lighting effect. Mobile computing devices such as smart phones and tablet computers may be equipped with cameras configured to utilize rolling shutter techniques to capture these coded light signals. The mobile computing devices may then extract and use the location information for navigation and positioning.

In some embodiments, the coded light signals may simply convey geographic coordinates. For instance, in some embodiments, the coded light signals carried in the lighting effects may convey location data formatted using a version of the World Geodetic System. In such embodiments, a location on Earth may be expressed using latitude, longitude and height. In other embodiments, the coded light signals may convey more literal data, such as “northwest corner of first floor,” “women's shoes,” “southeast corner of garage floor A2,” “floor5,” and so forth. In yet other embodiments, the coded light signals carried in the lighting effects may convey location data that is pertinent in a particular environment such as an underground parking lot or shopping mall. For example, the location data may include Cartesian coordinates defined relative to a predefined origin within the environment. While many of the following examples describe transmission of Cartesian coordinates in coded light signals, this is not meant to be limiting, and other coordinate systems, such as Polar coordinates, may be used instead.

Referring toFIG. 1, in one embodiment, a mobile computing device in the form of a smart phone100may be configured to calculate its location in an environment (e.g., garage, store, mall, airport, etc.) by determining a distance to the center of a lighting effect102projected onto a surface104by a light source106. In various embodiments, smart phone100may be equipped with a camera having a lens108, and may be configured to utilize rolling shutter to detect a coded light signal carried in the lighting effect.

Assume lighting effect102is located at point (X1, Y1, Z1), and that smart phone100is located at point (X2, Y2, Z2). In various embodiments, light source106may be configured to emit light that carries a coded light signal. In various embodiments, the coded light signal may carry information about a location of lighting effect102projected onto surface104. For example, the coded light signal may carry the location of the center of the lighting effect, (X1, Y1, Z1).

In various embodiments, smart phone100may have stored in memory a reference height of smart phone, hphone, which may be an estimate of a distance between smart phone100and surface104when smart phone100is carried in a typical manner. For example, if a user of smart phone100indicates that her age is 10, then smart phone100may assume an average height of a smart phone when carried by a typical ten-year-old girl. In other embodiments, hphonemay be conveyed by the coded light signal emitted by light source106.

In various embodiments, smart phone100may determine its orientation relative to surface104. For instance, in various embodiments, smart phone100may determine the angle δ between a vector represented by the line hphoneinFIG. 1and a first vector110extending from a focal point of a camera lens108of smart phone100to surface104along a central axis of the camera lens. To determine δ, smart phone100may utilize one or more of an accelerometer and/or a gyroscope.

In various embodiments, smart phone100may determine an angle ε between first vector110and a second vector112extending from the focal point to the center of lighting effect102. If camera lens108is pointed directly at the center of lighting effect102, ε may be zero. In various embodiments, the angle ε may be calculated based on a distance between a rendition of lighting effect102on a display of smart phone100and a center of the display. An example of this is shown inFIG. 2, where a rendition of lighting effect102is rendered on a display114of smart phone100. A distance116between a center of the rendition of lighting effect102and a center of display114may be proportionate to, or otherwise related to, the angle ε ofFIG. 1.

Once the angles δ, ε and the reference height hphoneare known, smart phone100may be configured to calculate various distances between smart phone100and a center of lighting effect102. For instance, smart phone may calculate ΔY using the following equation:
ΔY=hphone×tan(δ+ε).  (1)

FIGS. 1 and 2demonstrate a simple example of a mobile computing device (i.e. smart phone100) determining its location in an environment primarily in two dimensions, using a lighting effect. However, disclosed techniques are equally applicable in three dimensions. Further, if a mobile computing device detects more than one lighting effect102(or more than one light source106as described below), in various embodiments, the mobile computing device may calculate its location within the environment using information conveyed in a coded light signal carried by the brightest observed lighting effect102(or light source106).

FIG. 3depicts a three-dimensional example of how a mobile computing device such as smart phone100may determine its location within an environment. In this example, smart phone100may determine its location on the X/Y plane, (X1, Y1), based on its distance from light source106and a distance between light source106and the lighting effect102it projects. Assume that light source106projects a lighting effect102on a surface104that is the X/Y plane. In some embodiments, Z1may be based on hphoneinFIG. 1because it may represent an estimated height of smart phone100when held by a user. Assume also that light source106is located at point (X2, Y2, hlight), and that lighting effect102is projected onto surface104at point (X3, Y3, Z3).

Light source106may be commissioned in a process described below to emit a coded light signal. The coded light signal may convey various information about a location of lighting effect102in the environment. For example, the coded light signal may convey a reference distance hlightbetween light source106and surface104. Smart phone100may extract this information from the coded light signal and use it to perform various calculations to determine its location within the environment.

In various embodiments, smart phone100may calculate an angle ε2between a first vector, e.g., nphoneinFIG. 3, that is normal to surface104, and a second vector, r2, that extends from light source106to smart phone100. In various embodiments, and similarly as described above with reference toFIG. 2, this calculation may be based on an orientation of smart phone100as detected by a gravity sensor, as well as a distance116between a rendition of the light source106on display114of smart phone100and a center of display114.

In various embodiments, a distance between smart phone100and light source106along the X/Y plane, r2x,y, may be calculated based on hlightand ε2, using an equation such as one of the following:
r2x,y=hlight/tan(90°−ε2)  (2)
r2x,y=hlight×tan(ε2)  (3)
These equations and others described above and below are not meant to be limiting, and it should be understood that other equations may be performed in other orders without departing from the present disclosure.

In various embodiments, smart phone100may calculate an angle φ2between r2x,yand a reference vector. In various embodiments, the reference vector may be transmitted in the coded light signal emitted by light source106or preprogrammed into smart phone100. In some embodiments, the reference vector may be predefined relative to a magnetic pole (including parallel to the pole). For instance, inFIG. 3, the Y-axis is the reference vector, and is aligned with magnetic north/south. Smart phone100may be equipped with a sensor such as a compass to detect the magnetic pole, the reference vector, its own orientation relative to the reference vector, and ultimately, angle φ2. Once angle φ2is known, ΔX2and ΔY2may be calculated using equations such as the following:
ΔX2=r2x,y×sin(φ2)  (4)
ΔY2=r2x,y×cos(φ2)  (5)

In some embodiments, once ΔX2and ΔY2are known, smart phone100may determine its location within the environment further based on a location of lighting effect102. For instance, the coded light signal emitted by light source106may convey, in addition to hlight, the coordinates (X3, Y3, Z3) of lighting effect102as well as an angle ε3between a vector nI.ethat is normal to surface104and that extends from a center of lighting effect102, and a vector r3from light source106to the center of lighting effect102. Once ε3is known, a distance r3x,yof light source106from lighting effect102along surface104may be calculated based on hlightand ε3, using an equation such as one of the following:
r3x,y=hlight/tan(90°−ε3)  (6)
r3x,y=hlight×tan(ε3)  (7)

In various embodiments, the coded light signal emitted by light source106may convey an angle φ3between r3x,yand the Y-axis (which as mentioned above is aligned with magnetic north). Once r3x,yand φ3are known, ΔX3and ΔY3may be calculated, e.g., by smart phone100, using equations such as the following:
ΔX3=r3x,y×sin(φ3)  (8)
ΔY3=r3x,y×cos(φ3)  (9)

Once ΔX2, ΔX3, ΔY2and ΔY3are known, smart phone100may calculate its location (X1, Y1) on the X/Y plane relative to the location of the center of lighting effect, (X3, Y3), using an equation such as the following:
(X1, Y1)=(X3+ΔX2+ΔX3, Y3+ΔY2+ΔY3)  (10)
Z3may simply be hphone, unless lighting effect102is projected onto a different surface than the user holding smart phone100. In such case, Z3may be a difference in height between the two surfaces.

In some embodiments, light source106may be commissioned to emit a coded light signal that carries its own location, in addition to or instead of the location of the center of lighting effect102. In such embodiments, it may be possible for smart phone100to calculate its position using equations such as (2)-(5), without performing equations (6)-(9).

It should be noted that, in the simplest case where smart phone100is placed directly in the light beam emitted by light source106, e.g., on top of or near the center of lighting effect102, smart phone100may calculate its position as simply the position of lighting effect, (X3, Y3, Z3).

In some scenarios, the mobile computing device may move through an environment quickly. For example, a mobile computing device associated with a vehicle (e.g., a GPS navigation unit) may move through a tunnel, where GPS is unavailable, at a high rate of speed. Light sources in the tunnel may emit coded light signals conveying location information. Because the vehicle is moving quickly, a light sensor matrix may be installed on the vehicle. To compensate for short exposure time, in various embodiments, multiple light sources in the tunnel may emit coded light signals conveying the same location information, e.g., in a synchronized manner to create a longer beam.

As mentioned previously, in order for light source106to emit a coded light signal conveying information such as hlight, the location of the center of lighting effect (X3, Y3, Z3), φ3or ε3, it may first be commissioned with this data. In some embodiments, each light source106may be commissioned manually, e.g., by the manufacturer or by someone installing light source106in an environment. In some embodiments, light source106may be commissioned using a commissioning device. A commissioning device may in some embodiments be a portable computing device designed specifically for commissioning light sources. For instance, an autonomous robotic commissioning device may be configured to autonomously travel around an environment to multiple lighting effects102, where it commissions the corresponding light sources106. In other embodiments, the commissioning device may be a general purpose mobile computing device, such as a smart phone or tablet, that may be placed into a lighting effect102.

FIG. 4depicts one example of how an example commissioning device418may be used to commission light source106so that other mobile computing devices (e.g., smart phone100) are able to calculate their locations within an environment. As was the case withFIG. 3, assume that a center of lighting effect102is located at point (X3, Y3, Z3), and the light source106is located at point (X2, Y2, hlight). In some embodiments, light source106may emit a coded light signal identifying itself. In other embodiments, an identifier of light source106may be input into commissioning device418manually.

Commissioning device418may be positioned, or may position itself if autonomous, at the center of light effect102, i.e. at point (X3, Y3, Z3). Assume that commissioning device418knows its location, e.g., using GPS or by tracking wheel rotations and turns from a known starting point. Once commissioning device418is so positioned, it may commission light source106by transmitting information about the location of lighting effect102to light source106, e.g., using various communication technologies such as Wi-Fi, Bluetooth, NFC, RFID, coded light, and so forth.

For instance, commissioning device418may transmit its location (which is at the center of lighting effect102) to light source106. Commissioning device418may also transmit to light source106a reference height hlightof light source106. In some embodiments, commissioning device418may calculate and transmit to light source106various angles, such as angles φ3or ε3.

In various embodiments, commissioning device418may calculate the angle ε3between r3and the normal vector nI.e. In various embodiments, the angle ε3may be calculated using techniques similar to those used to calculate the angle ε inFIGS. 1 and 2. For instance, commissioning device418may know an orientation of its camera (or other light sensor), similar to the first vector110ofFIG. 1. Commissioning device418may then calculate ε3based on a difference between a center of a display (or a memory buffer containing two-dimensional data representing a captured image) and a rendition of light source106on the display (or the memory buffer).

In some embodiments, commissioning device418may additionally or alternatively calculate the angle φ3between r3x,yand a reference vector that is predefined relative to a magnetic pole. For instance, inFIG. 4, the reference vector is the Y-axis, which is predefined along the magnetic pole. Commissioning device418may be equipped with a sensor such as a compass to detect the magnetic pole, its own orientation relative to the magnetic pole, and ultimately, angle φ3. The commissioning device may then transmit this angle φ3to light source106.

In some embodiments, commissioning device418may transmit to light source106the location of light source106, although this is not required when using the techniques demonstrated inFIG. 3. For instance, based on the reference height hlightand the angle ε3, commissioning device418may calculate r3x,y. Once r3x,yis known, it can be used with the angle φ3to calculate ΔX3and ΔY3. These values may be added to the position of commissioning device418on the X/Y plane, (X3, Y3), to determine the position of light source106on the X/Y plane.

FIG. 5schematically depicts components of an example light source106, in accordance with various embodiments. Light source106may include one or more light-emitting diodes (LEDs)520and a controller522operably coupled with the one or more LEDs520and configured to selectively energize the one or more LEDs520to emit light carrying a coded light signal. As noted above, in various embodiments, the coded light signal may convey various information about a location of lighting effect102projected by the one or more LEDs onto surface104. For example, in some embodiments, the information about the location of lighting effect102includes a location of a center of lighting effect102. In some embodiments, the coded light signal also conveys a reference distance (e.g., hlight) between light source106and surface104.

In some embodiments, controller522may be configured to derive the information about the location of lighting effect102based on a direction of a light beam produced by the one or more LEDs520. For instance, light source106may be aware of its location, either by being commissioned by a commissioning device or via a GPS unit524. Light source106may also have stored in memory a distance (e.g., hlight) between light source106and surface104onto which it projects a lighting effect102. Using these values, as well as a direction of a light beam emitted by light source, light source106, e.g., by way of controller522, may be configured to calculate a location of lighting effect102. In other embodiments, controller522may be configured to derive the information about the location of the lighting effect based on a width of a light beam produced by the one or more LEDs520.

Although in examples described herein, lighting effect102has been projected on a horizontal surface, this is not meant to be limiting. Lighting effect102may be projected onto surfaces of any orientation, including horizontal, vertical, and anything in between. Moreover, surfaces104are not necessarily limited to floors. In some cases, the surfaces104may be raised surfaces of tables or other furniture. In such case, the Z-coordinate of lighting effect102and/or a reference distance between light source106and surface104(e.g., hlight) may reflect the raised surface.

FIG. 6depicts an example method600that may be implemented by a mobile computing device such as smart phone100to calculate its position within an environment, in accordance with various embodiments. At block602, a coded light signal may be received, e.g., by smart phone100from light source106. At block604, smart phone may extract a location of a lighting effect102produced by light source106on a surface104.

At block606, smart phone100may determine a reference distance. If a camera of smart phone100is pointed at lighting effect102, then the reference distance may be an estimated distance between smart phone100and surface104, e.g., hphoneinFIG. 1. If the camera of smart phone100is pointed at light source106, on the other hand, then the reference distance may by a distance between light source106and the surface104on which light source106projects its lighting effect102, e.g., hlightinFIGS. 3 and 4. In some cases, hphonemay be subtracted from hlightto reflect a true distance in a direction of the Z-axis between smart phone100and light source106.

At block608, smart phone100may determine its orientation relative to a magnetic pole, e.g., using a compass. For example, inFIG. 3, smart phone100determined the angle φ2. At block610, smart phone100may determine its orientation relative to surface104, e.g., using one or more accelerometers and/or gyroscopes. For example, smart phone100inFIG. 1determined the angle δ. At block612, smart phone100may determine an incident angle between a central axis of its camera and a vector from light source106or a center of lighting effect102to the camera's focal point. For instance, smart phone100inFIG. 1determined the angle ε as demonstrated inFIG. 2by determining a distance116between a center of display114and a rendition of lighting effect102on display114.

At block614, smart phone100may calculate a distance between itself and lighting effect102and/or light source106. For example, inFIG. 1, smart phone100used the sum of the two angles δ and ε inFIG. 1, in addition to the reference distance hphone, to calculate ΔY. Similar techniques were implemented by smart phone100inFIG. 3to determine r2x,yand r3x,y.

At block616, based on the distance between smart phone100and lighting effect102and/or light source106, as well as the location of lighting effect102(as conveyed by the coded light signal emitted by light source106), smart phone100may calculate its location in environment.

FIG. 7depicts an example method700that may be implemented using commissioning device418, in accordance with various embodiments. At block702, commissioning device418may be placed in lighting effect102, e.g., at its center. At block704, commissioning device418may determine its location, e.g., using GPS or by tracking turns and rotations of its wheels.

At block706, commissioning device418may determine its orientation relative to a magnetic pole, e.g., using a compass. For example, inFIG. 4, the commissioning device determined the angle φ3. At block708, commissioning device418may determine its orientation relative to surface104. For example, inFIG. 4, commissioning device418determined the angle ε3based at least in part on an orientation of its camera or light sensor.

At block710, commissioning device418may transmit the information determined at block704-708to light source106, e.g., using various communication technologies such as Wi-Fi, Bluetooth, coded light, NFC, RFID, and so forth.

Reference numerals appearing in the claims, if any, are provided merely for convenience and should not be construed as limiting the claims in any way.