FIELD OF THE DISCLOSURE

The present disclosure is directed generally to optimizing lighting timeout by fusing data captured by sensor bundles.

BACKGROUND

Automatic control of a light in a space fundamentally involves two decisions. First, a control mechanism must decide when to activate a light (the “onset”). Typical lighting systems are required to activate a light within 750 milliseconds of an occupant entering the space. Second, the control mechanism must decide when to deactivate the light when the occupant leaves the space (the “timeout”). Typical lighting systems are required to operate for at least 8,000 hours in between deactivations due to false positives, i.e., timeout when the space is occupied.

Traditionally, both onset and timeout decisions were made using passive infrared (PIR) sensors. PIR sensors detect motion of heat-emitting objects, including human bodies. PIR sensors can detect motion very quickly and are therefore ideally configured for onset detection. However, PIR sensors are poorly configured for presence detection. If an occupant does desk work involving very little motion, a PIR sensor may accordingly fail to detect the motion, causing the controller to turn off the light. The time between the last detected motion and the deactivation of the light is called the timeout interval. While the timeout interval may be improved using heuristics, the interval is typically not optimized, leading to the lights turning off when occupants are working in a relatively still position. The occupants often must move their hands or even get-up and walk around for the light to turn back on again. Accordingly, a more accurate sensor system to optimize timeout of a light is needed.

SUMMARY OF THE DISCLOSURE

The present disclosure is directed to inventive systems and methods for optimizing timeout of a lighting control in an environment, such as an office, by fusing data captured by two sensor modalities of a sensor bundle. The systems and methods analyze data collected by a presence sensor, such as a single pixel thermopile (SPT), and a motion sensor, such as a passive infrared (PIR) sensor. Analyzing data collected by these two types of sensors provides greater precision in occupancy determination, especially in cases where occupants are sitting relatively still for prolonged periods of time. In particular, the presence sensor is configured to detect the sustained presence of an occupant.

Generally, in one aspect, a lighting system for optimizing timeout of a luminaire in an environment is provided. The lighting system may include a motion sensor. The motion sensor may be configured to generate a motion signal. The motion sensor may be a PIR sensor.

The lighting system may include a presence sensor. The presence sensor may be configured to generate a presence signal. The presence sensor may be an SPT.

The lighting system may include a controller. The controller may be in communication with the luminaire, the motion sensor, and the presence sensor. The controller may be configured to determine if a timeout event has occurred based on the motion signal and a timeout detector. The timeout detector may include a motion threshold. The timeout detector may include an analysis period.

The controller may be further configured to determine if one or more persons are present in the environment based on the presence signal and a presence detector. In one example, the presence detector may include a step analysis module configured to determine if one or more persons are present in the environment.

The controller may be further configured to power off the luminaire if the timeout event has occurred and one or more persons are not present in the environment.

In one example, the controller may be further configured to update the timeout detector if the timeout event has occurred and one or more persons are present in the environment. The controller may be further configured to update the timeout detector by increasing an analysis period. The controller may be further configured to update the timeout detector by decreasing a motion threshold.

In one example, the controller may be further configured to determine if a power on event has occurred based on the motion signal and a power on detector. The controller may be further configured to power on the luminaire if the power on event has occurred.

Generally, in another aspect, a method for optimizing timeout of a luminaire in an environment is provided. The method may include generating, via a motion sensor, a motion signal. The method may further include generating, via a presence sensor, a presence signal. The method may further include determining, via a controller, if a timeout event has occurred based on the motion signal and a timeout detector. The method may further include determining, via the controller, if one or more persons are present in the environment based on the presence signal and a presence detector. The method may further include powering off the luminaire, via the controller, if the timeout event has occurred and one or more persons are not present in the environment.

In one example, the method may further include updating, via the controller, the timeout detector stored in the memory based on the motion signal if the timeout event has occurred and one or more persons are present in the environment. The updating may include increasing an analysis period of the timeout detector and/or decreasing a motion threshold of the timeout detector.

In one example, the method may further include performing, via the controller, a step analysis of the presence signal to determine if one or more persons are present in the environment.

In various implementations, a processor or controller may be associated with one or more storage media (generically referred to herein as “memory,” e.g., volatile and non-volatile computer memory such as RAM, PROM, EPROM, and EEPROM, floppy disks, compact disks, optical disks, magnetic tape, etc.). In some implementations, the storage media may be encoded with one or more programs that, when executed on one or more processors and/or controllers, perform at least some of the functions discussed herein.

Various storage media may be fixed within a processor or controller or may be transportable, such that the one or more programs stored thereon can be loaded into a processor or controller so as to implement various aspects as discussed herein. The terms “program” or “computer program” are used herein in a generic sense to refer to any type of computer code (e.g., software or microcode) that can be employed to program one or more processors or controllers.

It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. It should also be appreciated that terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein. These and other aspects of the various embodiments will be apparent from and elucidated with reference to the embodiment s) described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the various embodiments.

FIG. l is a schematic of a system for lighting control timeout optimization, in accordance with an example.

FIG. 2 is a further schematic of a system for lighting control timeout optimization, in accordance with an example.

FIGS. 3A to 3D are example presence signals undergoing signal processing.

FIG. 4 is a flowchart of a method for lighting control timeout optimization, in accordance with an example.

DETAILED DESCRIPTION OF EMBODIMENTS

The present disclosure is directed to inventive systems and methods for optimizing timeout of a lighting control in an environment, such as an office. The systems and methods analyze data collected by a presence sensor, such as a single pixel thermopile (SPT), and a motion sensor, such as a passive infrared (PIR) sensor. Analyzing data collected by these two types of sensors provides greater precision in occupancy determination, especially in cases where occupants are sitting relatively still for prolonged periods of time. The systems and methods may be configured to activate a luminaire when a PIR detects motion and an SPT detects presence. The systems and methods may be further configured to deactivate a luminaire when a PIR fails to detect motion and an SPT fails to detect presence. If, while a luminaire is activated, the PIR fails to detect motion and the SPT detects presence, the luminaire will remain activated, and the system may adjust the motion detection process.

With reference to FIGS. 1 and 2, in one aspect, a lighting system 100 for optimizing timeout of a luminaire 110 in an environment 120 is provided. The environment 120 may be an indoor or outdoor area for which it would be advantageous to activate and deactivate lights based on the occupancy. In one example, the environment 120 may be an individual office in an office building.

The lighting system 100 may include a motion sensor 130. The motion sensor 130 may be configured to generate a motion signal 160. The motion signal 160 may be an electronic representation of the movement within a field of view of the motion sensor 130. The motion sensor 130 may be a PIR sensor. In other examples, the motion sensor 130 may be any sensor or plurality of sensors, passive or active, capable of detecting motion. In some examples, the motion sensor 130 will be positioned in an office to detect motion of one or more persons 200 within the office. The motion signal 130 may include data designating each detected motion as a “minor”, “medium”, or “major” motion.

The lighting system 100 may include a presence sensor 140. The presence sensor 140 may be configured to generate a presence signal 170. The presence signal 170 may be an electronic representation of presence within a field of view of the presence sensor 170. The presence sensor 170 may be an SPT. An SPT generates a presence signal 170 in terms of temperature. Example presence signals 170 captured by an SPT are shown in FIGS.

3 A and 3B. In these example signals, the measured temperature noticeably increases, or “steps up” in the presence of one or more persons 200. In other examples, the presence sensor 140 may be any sensor or plurality of sensors, passive or active, capable of detecting presence. In some examples, the presence sensor 170 will be positioned in an office to detect motion of one or more persons 200 within the office. In some examples, the motion sensor 130 and the presence sensor 140 may be packaged together in a sensor bundle.

The lighting system 100 may include a controller 150. The controller 150 may include a memory 270. The controller 150 may be in communication with the luminaire 110, the motion sensor 130, and the presence sensor 140. The communication may be wired and/or wireless, depending on the application. In a preferred example, the motion sensor 130 provides a motion signal 160 to the controller 150 for analysis. Similarly, in another preferred example, the presence sensor 140 provides a presence signal 170 to the controller 150.

The controller 150 may be configured to determine if a timeout event 180 has occurred based on the motion signal 160 and a timeout detector 190. The timeout detector 190 comprises criteria, such as algorithms and variables, used by the controller 150 to analyze the motion signal 160. In one example, the controller 150 may analyze the motion signal 160 for criteria defined by the timeout detector 180 indicative of a lack of motion, and therefore, an unoccupied environment 120.

The timeout detector 190 may include a motion threshold 220. In one example, if the amplitude of the motion signal 160 exceeds the motion threshold 220, the environment 120 is presumed to be occupied by one or more persons 200. If the amplitude of the motion signal 160 fails to exceed the motion threshold 220, the environment 120 is presumed to be unoccupied. The motion threshold 220 may be optimized according to the environment 120.

The timeout detector 190 may include an analysis period 230. The analysis period 230 is the length of the time the controller 150 will analyze the motion signal 160 to determine if a timeout event 180 has occurred. In one example, if the motion signal 160 fails to exceed the motion threshold 220 during the analysis period 230, the controller 150 may determine the timeout event 180 has occurred.

The timeout detector 190 may include any other algorithms, values, or variables useful to analyze the motion signal 160 for human motion.

The controller 150 may be further configured to determine if one or more persons 200 are present in the environment 120 based on the presence signal 170 and a presence detector 210. The presence detector 210 comprises criteria, such as algorithms and variables, used by the controller 150 to analyze the presence signal 170. In one example, the controller 150 may analyze the presence signal 170 for criteria defined by the presence detector 210 indicative of a lack of presence, and therefore, an unoccupied environment 120.

In one example, the presence detector 210 may include a step analysis module 260 configured to determine if one or more persons 200 are present in the environment 120. The step analysis module 260 may be configured to analyze the presence signal 170 for one or more “steps up” and “steps down” in temperature. A “step up” in temperature is likely indicative of a person 200 entering the environment 120, while a “step down” is likely indicative of a person 200 leaving. Example presence signals 170 are shown in FIGS. 3A and 3B. In these example signals, the measured temperature noticeably increases, or “steps up” when one or more persons 200 are in the field of view of the presence sensor 140.

With reference to FIG. 3C, the step analysis module 260 may be configured to convolve the presence signal 170 with a step function. The convolved signal is shown in FIG. 3D. As shown in FIGS. 3C and 3D, the convolved signal will peak if the shape of the presence signal 170 corresponds to the step function. More specifically, the convolved signal will peak (or crest) to a maximum value during a “step up”, and fall (or trough) to a minimum value during a “step down”. By further processing the convolved signal for peak detection, the controller 150 may determine if a “step up” or “step down” has occurred, and then further determine if a person 200 has entered or left the field of view of the presence sensor 140.

The controller 150 may be further configured to power off the luminaire 110 if the timeout event 180 has occurred and one or more persons 200 are not present in the environment 120. Analyzing data captured by both a motion sensor 130 and a presence sensor 140 prevents the controller 150 from inconveniently deactivating the luminaire 110 when the one or more persons 200 sit still for a prolonged period.

In one example, the controller 150 may be further configured to update the timeout detector 190 if the timeout event 180 has occurred and one or more persons 200 are present in the environment 120. This updating can be used to optimize the timeout detector 190 to prevent the detection of a timeout event 180 when one or more persons 200 are present in the environment 120. In an example, the controller 150 may be further configured to update the timeout detector 190 by increasing an analysis period 230. In another example, the controller 150 may be configured to update the timeout detector 190 by decreasing a motion threshold 220.

In a specific example of repeated occurrences of a timeout event 180 while persons 200 are present in the environment 120, the analysis period 230 may be successively increased at a pre-determined rate. The pre-determined rate may be dynamically adjusted based on a variety of factors, including the number of successive false positive timeout events 180. In an example, in response to a first false positive timeout event 180, the controller 150 may double the analysis period 230. If the first false positive timeout event 180 is closely followed by a second, the controller may again double the analysis period 230. This successive doubling results in an exponential increase of the analysis period 230. This exponential increase may continue until false positive timeout events 180 no longer occur.

Exponentially increasing the analysis period 230 may result in energy inefficiencies due to the luminaire 110 remaining activated during a long analysis period 230 in which no persons 200 are present in the environment 120. Accordingly, the controller 150 may increase the analysis period 230 in a manner other than simple doubling. In one example, after doubling the analysis period 230 a certain number of times, the analysis period 230 may be multiplied by a factor slightly less than 2.00, such as 1.90 or 1.95 when a false positive timeout event 180 occurs.

Further, if the controller 150 detects a succession of non-false positive timeout events 180, the controller 150 may optimize the responsiveness of the lighting system 100 by decreasing the analysis period 230 by a pre-determined rate.

In another specific example, stored data captured by the presence sensor 140 may be mined to optimize the timeout detector 190. The stored data may include presence signals 170 previously captured by the presence sensor 140. A high degree of variability in the stored data over time may be indicative of frequent motion activity. Accordingly, if the controller 150 determines the stored data exhibits a high degree of variability, the controller 150 may decrease the analysis period 230 by a pre-determined rate. Similarly, a low degree of variability may be indicative of infrequent motion activity. Accordingly, if the controller 150 determines the stored data exhibits a low degree of variability, the controller 150 may increase the analysis period 230 by a pre-determined rate.

In one example, the controller 150 may be further configured to determine if a power on event 240 has occurred based on the motion signal 160 and a power on detector 250. PIR sensors are specifically preferred to determine a power on event due to their rapid data capture and processing rates. The controller 150 may be further configured to power on the luminaire 110 if the power on event 240 has occurred. In other embodiments, the controller 150 may be configured to determine the occurrence of a power on event 240 based on the presence signal 170.

With reference to FIG. 4, in another aspect, a method 500 for optimizing timeout of a luminaire in an environment is provided. The method 500 may include generating 510, via a motion sensor, a motion signal. The method 500 may further include generating 520, via a presence sensor, a presence signal. The method 500 may further include determining 530, via a controller, if a timeout event has occurred based on the motion signal and a timeout detector. The method 500 may further include determining 540, via the controller, if one or more persons are present in the environment based on the presence signal and a presence detector. The method 500 may further include powering off 550 the luminaire, via the controller, if the timeout event has occurred and one or more persons are not present in the environment.

In one example, the method 500 may further include updating 560, via the controller, the timeout detector stored in the memory based on the motion signal if the timeout event has occurred and one or more persons are present in the environment. The updating 560 may include increasing 580 an analysis period of the timeout detector and/or decreasing 590 a motion threshold of the timeout detector.

In one example, the method 500 may further include performing 570, via the controller, a step analysis of the presence signal to determine if one or more persons are present in the environment.

All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms. The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified.

As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.”

As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified.

It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.

In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively.

While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.