Abstract: A controller dynamically identifies a switching frequency based power converter output load condition, input voltage, and/or temperature. The controller updates the operating switching frequency to the identified target switching frequency when the identified switching frequency is sufficiently different than a current operating switching frequency of the power converter. In this respect, switching frequency may be dynamically controlled to strike a balance between avoiding saturation of inductive elements and efficient operation of a power converter. A controller may also dynamically control switching frequency by having a thermo resistor incorporated into circuitry that determines switching frequency such that an increase in temperature beyond the threshold temperature directly causes a decrease in switching frequency.

Abstract: A method of Light-based Communication (LCom) using camera frame-rate based light modulation is provided. The method includes receiving light having modulated light properties that vary at a first frequency from a LCom-enabled luminaire by an image capture device using a global shutter image capture process, comparing light properties received at the image capture device over sequential image capture instances, and determining, from the compared light properties, data encoded by the modulated light.

Abstract: Techniques are disclosed for augmenting light-based communication (LCom) receiver positioning using, for example, an inertial navigation system (INS). An LCom receiver INS may utilize one or more on-board accelerometers and gyroscopic sensors to calculate, via dead reckoning, the position, orientation, and velocity of the receiver. In this manner, the receiver can calculate its relative position using the INS based on a reference point or location. In some cases, the receiver may also or alternatively determine its location or position using a global positioning system (GPS), Wi-Fi-based positioning system (WPS), or some other suitable positioning system. When no LCom signals are in the FOV of the receiver and/or the link is lost to other positioning systems, the receiver INS may be used to augment the receiver positioning. In some cases, the INS mode may run parallel to other positioning techniques to continuously calculate the relative position of the receiver.

Abstract: Techniques are disclosed for measuring an amount of flicker produced by a light source. In one embodiment, a flicker measuring device includes a photo sensor to measure the amount of light produced by the light source, a dedicated processor to receive and process data from the photo sensor, a memory bus coupled to an analog-to-digital converter (ADC) and to a first memory, and a direct memory access (DMA) bus coupled to the ADC and to a second memory. In another embodiment, a flicker measuring system uses a light sensor, an associated circuit and a portable computing device (PCD), such as a smart phone, to measure an amount of flicker produced by a light source by sending an electrical signal from the light source and associated circuit via an audio output to an audio sub-system of the PCD, so that the PCD may calculate the flicker value.

Abstract: Various embodiments disclosed herein include a method for determining the position of a computing device. The method may include obtaining, by the computing device, an image of a subset of luminaries from a plurality of luminaires located in an indoor environment, in which each subset grouping of luminaires in the plurality of luminaires is uniquely identifiable. The computing device may then compare the subset of luminaires to a database storing each uniquely identifiable subset grouping of luminaires in the plurality of luminaires, in which the database includes position information for each luminaire in the plurality of luminaires, and determine the position of the computing device based on the comparison of the subset of luminaries to the database.

Abstract: Techniques and architecture are disclosed for mobile transport systems configured to determine vehicle positions within an area using light-based communication signals. The system includes a plurality of luminaires located in an area and configured to transmit luminaire position data recognizable by a sensor disposed on a vehicle. The sensor receives an image of a luminaire including a light-based communication signal encoded with luminaire position data. Luminaire position data can be combined with luminaire layout information to determine a known location of the luminaire. A vehicle position relative to the known luminaire location can be determined based on mathematical relationships. Vehicle orientation relative to the area can be determined based an asymmetric fiducial pattern or multiple known luminaire locations. The system can combine a vehicle position relative to a known luminaire location with vehicle orientation relative to the area to determine a vehicle position relative to the area.

Abstract: A light guide arrangement for a mobile communications device for optical data transmission by an optoelectronic interface component of the communications device is provided. The light guide arrangement includes a light guide body with a greatest extent in the principal light guiding direction, a first optical coupling member for coupling the optoelectronic interface component to the light guide body, a second optical coupling member with a first lens element that has a first optical axis transverse to the principal light guiding direction and with a first optical deflection element arranged along the first optical axis, and a third optical coupling member with a second lens element that has a second optical axis transverse to the principal light guiding direction and with a second optical deflection element arranged along the second optical axis. The second optical axis differs from the first optical axis.

Abstract: Techniques are disclosed for projecting visible cues to assist with light-based communication (LCom), the visible cues referred to herein as visual hotspots. The visual hotspots can be projected, for example, using a luminaire that may be LCom-enabled. The visual hotspots may be projected onto the floor of an area including an LCom system. The visual hotspots can be used for numerous benefits, including alerting a potential user that LCom is available, educating the user about LCom technology, and assisting the user in using the LCom signals available in the area. The visual hotspots may include images, symbols, cues, characters (e.g., letters, words, numbers, etc.), indicators, logos, or any other suitable content. In some cases, the visual hotspots may be interactive, such that a user can scan the hotspot to cause an action to occur (e.g., launch an application or website).

Abstract: Techniques are disclosed for emitting position information from luminaires. Luminaire position information may be emitted via a light-based communication (LCom) signal that comprises data including the position information. The data may include relative and/or absolute position information for the luminaire and may indicate the physical location of the luminaire. Relative position information for the luminaire may include coordinates relative to a point of origin within the environment. Absolute position information for the luminaire may include global coordinates for the luminaire. In some cases, the absolute position information for a luminaire may be calculated using position information for the luminaire relative to a point of origin and the absolute position of the point of origin. The data may also include an environment identifier, which may indicate a map to use for the interpretation of position information for the luminaire. The techniques can be used for both stationary and mobile luminaires.

Abstract: Techniques are disclosed for augmenting global positioning system (GPS)-based navigation via light-based communication (LCom). In accordance with some embodiments, a light-sensing device, such as a camera or an ambient light sensor configured as described herein, may be used to detect an LCom signal transmitted by a local LCom-enabled solid-state luminaire. The LCom signal may include data about the location of the transmitting luminaire, and in some cases that location data may be used, for example, in computing the amount of time that it would take to navigate indoors to the luminaire's location. In some instances, GPS data also may be considered to calculate the total trip duration for an entire trip, including time spent indoors and outdoors. In some other cases, the location data and, if available, GPS data may be used, for example, in computing an automotive navigation route.

Abstract: Techniques are disclosed for projecting visible cues to assist with light-based communication (LCom), the visible cues referred to herein as visual hotspots. The visual hotspots can be projected, for example, using a luminaire that may be LCom-enabled. The visual hotspots may be projected onto the floor of an area including an LCom system. The visual hotspots can be used for numerous benefits, including alerting a potential user that LCom is available, educating the user about LCom technology, and assisting the user in using the LCom signals available in the area. The visual hotspots may include images, symbols, cues, characters (e.g., letters, words, numbers, etc.), indicators, logos, or any other suitable content. In some cases, the visual hotspots may be interactive, such that a user can scan the hotspot to cause an action to occur (e.g., launch an application or website).

Abstract: Techniques are disclosed for assessing the conditions of LEDs and power supplies of solid state lighting systems. The techniques can be used, for example, to measure the capacitance of an output capacitor C in a switch-mode power supply (SMPS), and to measure the condition of the LEDs being driven by that power supply. In some cases, this assessment can be implemented in a lighting controller that controls the lighting system, which may be configured to simultaneously determine C and the conditions of LEDs. In one example case, the techniques can be implemented, for instance, in a micro-controller operating the lighting system. A lighting system implementing the techniques can be periodically assessed so as to provide real-time diagnostic capability. Numerous example embodiments of SMPS LED lighting systems will be apparent in light of this disclosure.

Abstract: Techniques are disclosed for enhancing indoor navigation using light-based communication (LCom). In some embodiments, an LCom-enabled luminaire configured as described herein may include or have access to a sensor configured to detect a hazardous condition. In response to detection of a hazard, the LCom-enabled luminaire may adjust its light output, transmit an LCom signal, or both, in accordance with some embodiments. A given LCom signal may include data that may be utilized by a recipient computing device, for example, in providing emergency evacuation routing or other indoor navigation with hazard avoidance, emergency assistance, or both. In a network of such luminaires, data distribution via inter-luminaire communication may be provided, in accordance with some embodiments, via an optical interface or other wired or wireless communication means. In some cases, the network may include a luminaire that is not LCom-enabled yet still configured for inter-luminaire communication.

Abstract: Techniques for supplying auxiliary power to lighting driver circuitry are disclosed. An auxiliary power supply can be used, for example, to provide auxiliary power to a current source that drives an LED string. In some embodiments, the LED string is effectively used as a series resistor to charge a capacitor that provides the auxiliary voltage Vaux. As soon as the capacitor is charged to a given threshold, the LED string can be disconnected from the capacitor and the current through the LED string bypasses the auxiliary supply circuit. Thus, the current source provides a current through the LED string, which in turn may be selectively fed to the auxiliary power supply to provide auxiliary power back to the current source or to provide auxiliary power to other circuitry.

Abstract: Techniques are disclosed for providing light-based communication (LCom) between a receiver device and one or more transmitting LCom-enabled luminaires. In accordance with some embodiments, LCom data to be transmitted may be allocated over multiple colors of light output by multiple LCom-enabled luminaires and transmitted in parallel across the multiple colors of light using a time division multiple access (TDMA) scheme. In some cases, the disclosed techniques can be used, for example, to allow for multiple LCom-enabled luminaires to communicate simultaneously over multiple active LCom channels with a single receiver device. In some instances, the disclosed techniques may be used, for example, to provide channel redundancy that facilitates successful completion of LCom data transmission when an LCom channel is broken. In some instances, the disclosed techniques may be used, for example, to provide more accurate positioning for indoor navigation.

Abstract: Techniques are disclosed for coding light-based communication (LCom) data in a manner that allows for detection thereof, for example, via a standard low-speed (e.g., 30 frames per second) smartphone camera. In accordance with some embodiments, the disclosed techniques can be used, for example, in encoding and decoding LCom data in a manner that: (1) prevents or otherwise minimizes perceivable flicker of the light output by a transmitting LCom-enabled luminaire; and/or (2) avoids or otherwise reduces a need for additional, specialized receiver hardware at the receiver computing device including the camera. In some cases, the disclosed techniques can be used, for example, to enhance the baud rate between a transmitting LCom-enabled luminaire and a receiver device.

Abstract: Techniques are disclosed for spatially resolving received light-based communication (LCom) signals. In an example case where one or more LCom signals are in the field of view (FOV) of an LCom receiver, the image representing the FOV may be captured and segmented into non-overlapping cells, such as hexagonal, triangular, rectangular, or circular shaped cells. Each LCom signal may be interpreted as a unique pixel cluster comprising one or more of the cells. In some cases, the LCom signals in the FOV may be received from multiple LCom-enabled luminaires and/or a single LCom-enabled luminaire having multiple light panels. The benefits of being able to spatially resolve received LCom signals may include establishing a link with multiple LCom signals within the FOV of a receiver without conflict and/or determining the location of those LCom signals, improving signal to noise ratio, augmenting position information, enhancing sampling frequency, and improving communication speed.

Abstract: Techniques are disclosed for programming a luminaire with location information, referred to herein as commissioning. Location information may include relative location information (e.g., the position of the luminaire relative to a reference point) and/or absolute location information (e.g., global coordinates for the luminaire). A commissioned luminaire can be configured to emit its location information via light-based communication (LCom). In some cases, the luminaire can be commissioned manually, by hard coding the luminaire with its location either at the luminaire itself or using a device (e.g., a smartphone, tablet, or a dedicated luminaire commissioning device) to program the luminaire with location information. In some cases, the luminaire can be commissioned automatically. In some cases, the luminaire may be configured to provide visual, aural, or tactile feedback to indicate that the luminaire has not received location data or that the luminaire has been moved.

Abstract: Techniques are disclosed for enhancing indoor navigation using light-based communication (LCom). In some embodiments, an LCom-enabled luminaire configured as described herein may include or have access to a sensor configured to detect a hazardous condition. In response to detection of a hazard, the LCom-enabled luminaire may adjust its light output, transmit an LCom signal, or both, in accordance with some embodiments. A given LCom signal may include data that may be utilized by a recipient computing device, for example, in providing emergency evacuation routing or other indoor navigation with hazard avoidance, emergency assistance, or both. In a network of such luminaires, data distribution via inter-luminaire communication may be provided, in accordance with some embodiments, via an optical interface or other wired or wireless communication means. In some cases, the network may include a luminaire that is not LCom-enabled yet still configured for inter-luminaire communication.

Abstract: Techniques are disclosed for projecting visible cues to assist with light-based communication (LCom), the visible cues referred to herein as visual hotspots. The visual hotspots can be projected, for example, using a luminaire that may be LCom-enabled. The visual hotspots may be projected onto the floor of an area including an LCom system. The visual hotspots can be used for numerous benefits, including alerting a potential user that LCom is available, educating the user about LCom technology, and assisting the user in using the LCom signals available in the area. The visual hotspots may include images, symbols, cues, characters (e.g., letters, words, numbers, etc.), indicators, logos, or any other suitable content. In some cases, the visual hotspots may be interactive, such that a user can scan the hotspot to cause an action to occur (e.g., launch an application or website).