Identifying problematic light sources

Abstract

A mechanism for identifying any light source, in a plurality of light sources, that undergoes power cycling when activated. Any such light source is identified by processing power information and activation information. The power information indicates power up and power down times of each light source. The activation information indicates times at which a control arrangement requests activation of each light source.

Description

[0001] 2024PF80381

[0002] 1

[0003] Identifying problematic light sources

[0004] FIELD OF THE INVENTION

[0005] The present invention relates to the field of light installations, and in particular to the identification of problematic light sources in a light installation.

[0006] BACKGROUND OF THE INVENTION

[0007] Artificial lighting products and systems, such as light sources, are increasing in popularity as a solution for lighting or illuminating an environment. One example environment is in a light installation for civil infrastructure, in which light sources are used to illuminate streets, roads, pathways and / or outdoor areas.

[0008] US2009222223 Al relates to system and method for streetlight monitoring diagnostics. Example diagnostics can determine a status such as a fixture malfunction, a cycling condition, a miswiring configuration, or another condition. The determined status can be wirelessly transmitted from the intelligent luminaire manager or other radio frequency device to a network server via a network. The network may be a network of intelligent luminaire managers and / or RF devices.

[0009] There is a demand for such light installations to be reliable, and for misbehaving light sources to be accurately identified. One form of problematic light source is a light source that does not reliably activate (i. e. , turn on) when requested by a control arrangement for the light installation.

[0010] There is therefore an ongoing desire to facilitate accurate identification of misbehaving light sources.

[0011] SUMMARY OF THE INVENTION

[0012] The invention is defined by the claims.

[0013] In accordance with a proposed approach, there is provided a computer-implemented method for identifying any first light sources amongst a plurality of light sources.

[0014] The method comprises obtaining power information indicating, for each of the plurality of light sources, any first power change times at which there is a decrease in power2024PF80381

[0015] 2

[0016] provided to said light source, and any second power change times at which there is an increase in power provided to said light source. The method further comprises obtaining activation information indicating, for each of the plurality of light sources, any activation times at which a control arrangement requests said light source to change from a deactivated state, in which the light source draws no or negligible power, to an activated state in which the light source draws power. The method then processes the power information and the activation information to identify any first light sources in the plurality of light sources.

[0017] A first light source is a light source for which the power information indicates that a set of one or more first power change times for said light source each occurs no more than a first predetermined period of time after any activation time for said light source, and the power information indicates that at least one second power change time for said light source occurs approximately a second predetermined period of time after any of the set of one or more first power change times.

[0018] The present disclosure provides a mechanism for identifying first light sources that are predicted to undergo (undesirable) power cycling responsive to a request to activate the light source. In particular, it is recognized that there is a probability (but not a guarantee) that a supply power to a driver arrangement for a light source will become volatile if many light sources are requested to be activated at a same time. It is recognized that this volatility materializes as a power cycling of the light source, as the driver arrangements resets in a protective mode (e.g., to reduce a risk of damage to the driver arrangement due to overvoltage or over-current conditions).

[0019] This proposed approach thereby provides efficient and effective identification of light sources within a larger group by analyzing their power status in relation to activation requests. In particular, light sources that undergo undesirable power cycles, due to volatile characteristics of a power supply, responsive to an activation request can be identified.

[0020] In some embodiments, for each light source, the second predetermined period of time is an expected time taken for a driver arrangement for powering said light source to restart. This approach recognizes that the delay between a power down and power up of a light source, due to power supply volatility when an activation request is made, is dependent upon the reset time for a driver arrangement of the light source.

[0021] In particular, the second predetermined period of time may be an expected time for the driver arrangement to restart in a protective mode responsive to voltage volatility, voltage oscillation, unusual or unexpected voltage shape, an overvoltage or overcurrent condition of the driver arrangement or shortage of voltage and / or current. In2024PF80381

[0022] 3

[0023] particular, the second predetermined period of time may be an expected time for the driver arrangement to undergo a protective restart, examples of which are well known in the art.

[0024] In some embodiments, for each light source, at least one second power change time occurs approximately the second predetermined period of time after any first power change time when the difference between at least one second power change time and any first power change time is within a predetermined error margin of the second predetermined period of time. This approach introduces flexibility in the identification process, accommodating slight variations in timing that may occur due to real-world factors. It improves the robustness of the method, reducing false negatives in identification of any first light sources.

[0025] In some embodiments, the predetermined error margin is no more than 10% of the second predetermined period of time. By setting a specific error margin, it is possible to balance or compromise precision with practicality in light source identification. More particularly, this embodiment helps maintain high accuracy in identifying any first light source while allowing for (minor or negligible) timing discrepancies that may occur.

[0026] In some embodiments, the power information comprises a plurality of data entries, each data entry identifying: an identity of one of the plurality of light sources; a power change time for the identified light source; and information indicating whether the power change for the identified light source increases or decreases a power provided to the light source.

[0027] In some embodiments, the step of obtaining power information comprises obtaining initial power information indicating, for each of the plurality of light sources, any first power change times and any second power change times, and producing the power information by filtering the initial power information to remove reference to any first power change time and second power change time that meets one or more predetermined criteria.

[0028] Filtering the initial power information helps to focus or direct the processing or identification of the first light sources on light sources that are more likely to exhibit or demonstrate the desired characteristic to be identified (i.e., power cycling after a request to activate).

[0029] In some embodiments, the one or more predetermined criteria includes a first predetermined criterion that the first power change time or second power change time is a power change time for a light source associated with power change times distributed across a predetermined window of time. This criterion helps identify and exclude light sources with erratic or continuous power fluctuations, i.e., faulty light sources. This reduces an amount of2024PF80381

[0030] 4

[0031] data needed to be processed in subsequent steps, thereby improving an efficiency of the identification process.

[0032] In some embodiments, the first predetermined criterion is that the first power change time or second power change time is a power change time for a light source having more than a predetermined number of first and / or second power change times within the predetermined window of time. This provides a technique for identifying light sources that are likely to be faulty, rather than those that demonstrate the target error.

[0033] In some embodiments, the one or more predetermined criteria includes a second predetermined criterion that a first power change time for a light source occurs no earlier than a third predetermined period of time before a second power change time for the same light source, and the third predetermined period of time is less than the second predetermined period of time. This criterion helps identify rapid power fluctuations that may not be relevant to the primary identification task. In particular, such fluctuations may result from the driver arrangement for the light source undergoing an expected “watchdog” reset and / or software reset. This allows the first light source identification portion of the method to focus on power changes that are more likely to be associated with the specific behavior of interest.

[0034] In some embodiments, the third predetermined period of time is no greater than 5 seconds. By specifying a short time frame, this feature helps eliminate very brief power fluctuations from consideration. It focuses the analysis on more significant and sustained power changes that are more likely to be indicative of the light source power cycling resultant from a power supply fluctuation after an activation request.

[0035] In some embodiments, the third predetermined period of time is a time required for a driver arrangement of the light source to perform a software-defined reboot. Typically, this time period is extremely short, e.g., less than 5 seconds.

[0036] In some embodiments, the one or more predetermined criteria includes a third predetermined criterion that a second power change time for a light source occurs no later than the third predetermined period of time after a first power change time for the same light source.

[0037] In some embodiments, the one or more predetermined criteria includes a fourth predetermined criterion that a first power change time for a light source occurs between a fourth predetermined period of time and a fifth predetermined period of time before a second power change time for the same light source; the one or more predetermined criteria includes a fifth predetermined criterion that a second power change time for a light2024PF80381

[0038] 5

[0039] source occurs between the fourth predetermined period of time and the fifth predetermined period of time after a first power change time for the same light source; the fourth predetermined period of time is less than the second predetermined period of time; and the fifth predetermined period of time is less than the second predetermined period of time.

[0040] In some embodiments, the method further comprises defining a future activation time for each first light source, wherein a separation between future activation times of first light sources is no less than an expected time for a driver arrangement for powering each first light source to restart following an abnormal voltage or current supply condition.

[0041] By way of working example, the separation between future activation times of first light source may be no less than 3 minutes. This approach aims to reduce a risk of future activation(s) of the first light sources resulting in the first light sources power cycling. In particular, by staggering the activation of the first light sources for future activations, there is a reduced risk that the attempted activation of the first light source(s) will result in inrush current and / or voltage volatility of the power supply.

[0042] In accordance with another proposed approach, there is provided a computer program product comprising computer program code means which, when executed on a computing device having a processing system, cause the processing system to perform all of the steps of the method according to any one of the previously described embodiments.

[0043] There is also provided a processing system configured to identify any first light sources amongst a plurality of light sources.

[0044] The processing system is configured to obtain power information indicating, for each of the plurality of light sources, any first power change times at which there is a decrease in power provided to said light source, and any second power change times at which there is an increase in power provided to said light source. The processing system is further configured to obtain activation information indicating, for each of the plurality of light sources, any activation times at which a control arrangement requests said light source to change from a deactivated state, in which the light source draws no or negligible power, to an activated state in which the light source draws power. The processing system is then configured to process the power information and the activation information to identify any first light sources in the plurality of light sources.

[0045] A first light source is a light source for which the power information indicates that a set of one or more first power change times for said light source each occurs no more than a first predetermined period of time after any activation time for said light source, and2024PF80381

[0046] 6

[0047] the power information indicates that at least one second power change time for said light source occurs approximately a second predetermined period of time after any of the set of one or more first power change times.

[0048] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.

[0049] BRIEF DESCRIPTION OF THE DRAWINGS

[0050] For a better understanding of the invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:

[0051] Fig. 1 illustrates an environment in which embodiments may be employed; Fig. 2 illustrates a proposed method;

[0052] Fig. 3 illustrates a step for use in a proposed method;

[0053] Fig. 4 illustrates another proposed method; and

[0054] Fig. 5 illustrates a further proposed method.

[0055] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0056] The invention will be described with reference to the Figures.

[0057] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, systems and methods of the present invention will become better understood from the following description, appended claims, and accompanying drawings. It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.

[0058] The invention provides a mechanism for identifying any light source, in a plurality of light sources, that undergoes power cycling when activated. Any such light source is identified by processing power information and activation information. The power information indicates power up and power down times of each light source. The activation information indicates times at which a control arrangement requests activation of each light source.2024PF80381

[0059] 7

[0060] Figure 1 illustrates an environment 100 in which a proposed approach may be employed. The environment 100 is embodied as an outdoor environment comprising a light installation formed of a plurality of luminaires.

[0061] Each luminaire 101, 102, 103, 104 comprises a respective light source and drive arrangement. The drive arrangement is configured to define the power provided to the light source. More particularly, each drive arrangement is connected to a mains power supply and converts the main power supply into a drive power for driving the light source. The light source emits light responsive to the drive power.

[0062] Example light sources (e.g., LED arrangements, halogen bulb arrangements and so on) and example drive arrangements (e.g., AC -DC converters) are well known in the art, and are not described in detail for the sake of conciseness.

[0063] The light installation further comprises a control arrangement 110. The control arrangement is configured to communicate with each luminaire to define an operation of at least the drive arrangement.

[0064] In particular, for each light source, the control arrangement is configured to control at least whether or not the drive arrangement is to provide power to the light source. In this way, the control arrangement is able to control at least whether the light source is to be activated (i.e. , emitting light) or deactivated (i. e. , not emitting light). Put another way, the control arrangement is able to at least request a light source to be activated or to be deactivated. Appropriate mechanisms for making such requests are well known to the skilled person, e.g., using control signals, wired / wireless communications and so on.

[0065] In some examples, the control arrangement may further control, for each light source, an intensity of the light emitted by the light source, e.g., by defining an amount of power that the drive arrangement is to provide to the light source. Appropriate control techniques are well known to the skilled person.

[0066] For a light installation in an outdoor environment, the control arrangement 110 may control the light sources according to a predefined schedule. In particular, the control arrangement may be configured to, for each light source, activate the light source at a first time of day (e.g., sunset or a time defined with respect to sunset) and / or deactivate the light source at a second time of day (e.g., sunrise, dawn or a time defined with respect to sunrise).

[0067] The present disclosure recognizes that a first type of misbehaving light source is a light source that, after the control arrangement requests that the light source be activated, undergoes one or more power cycles (i.e., deactivates before activating again) until reaching2024PF80381

[0068] 8

[0069] a stable activation state. A misbehaving light source of the first type may be labelled a first light source.

[0070] It has been recognized that one cause of such misbehavior occurs when there is an inrush current and / or voltage volatility from a mains supply to a driver arrangement of such a light source (i. e. , a supply volatility). This inrush current and / or voltage volatility will cause the driver arrangement to temporarily shut down and then restart. One cause of such an inrush current and / or voltage volatility is when multiple lights sources are activated simultaneously.

[0071] However, not all driver arrangements that are turned on at or near the same time will result in a misbehaving light source. This may, for instance, be due to variations in the local power supply conditions and / or the particular design or configuration(s) of the driver arrangements. Given these complexities, there is a demand for a method to identify and characterize problematic light sources in a light installation, as the behavior of individual light sources may not always be consistent or predictable based solely on their activation timing.

[0072] The present disclosure proposes to process power information and activation information to identify any misbehaving light sources of the first type (i.e., first light sources).

[0073] The power information indicates, for each of a plurality of light sources (e.g., of a light installation), any first or second power change times. A first power change time is a time at which there is a decrease in power provided to said light source (i.e., a change in the drive power), and therefore a decrease in intensity of light output. A second power change time is a time at which there is an increase in power provided to said light source (i.e., a change in the drive power), and therefore an increase in intensity of light output.

[0074] As a working example, the power information may comprise a plurality of data entries. For instance, the power information may be structured as a table in which each data entry represents a different row. Each data entry may effectively represent a power change event, in which there is a change of power provided to one of the plurality of light sources.

[0075] In this working example, each data entry may identify at least the following: an identity of the light source; a power change time for the identified light source (e.g., in the form of a timestamp) and a power change (i.e., an increase or decrease in power provided to the light source) at the power change time.2024PF80381

[0076] 9

[0077] Thus, the power change indicates at least whether the power provided to the identified light source has increased or decreased in magnitude. For instance, the power change may indicate a power level of the power provided to the light source. As another example, the power change may indicate a brightness or intensity of light emitted by the light source.

[0078] For instance, each data entry may effectively comprise a light source ID; a timestamp (representing the power change time) and a power level.

[0079] Table 1 provides an illustrative example of a portion of power information. Table headings are provided for clarity, and may be omitted in practice.

[0080] Light Source ID Power Change Event Time Light Level (%)

[0081] 1 2024-04-11 18:43:30 100

[0082] 2 2024-04-11 19:40:26 0 2 2024-04-11 19:40:27 100

[0083] 1 2024-04-11 19:40:37 70

[0084] TABLE 1

[0085] The power information may be generated through a distributed reporting system where individual light sources (or the corresponding luminaires_ communicate changes in their power status to a central server. In some implementations, the control arrangement may define or incorporate this central server.

[0086] By way of example, each light source or luminaire may be equipped with sensors or monitoring components that detect changes in the power provided to the light source. Examples include a voltage / current monitoring system or a light monitoring system. When a change is detected, the light source or luminaire may send a message to the central server. This message may include information such as the light source's unique identifier, the timestamp of the power change, and the new power level or state.

[0087] The central server may receive these messages in real-time from multiple light sources across the light installation. Upon receipt, the server may process and store this information, e.g., organizing it into a structured format to produce the power information.

[0088] The activation information indicates, for each of the plurality of light sources, any activation times. An activation time is a time at which there is a request from the control2024PF80381

[0089] 10

[0090] arrangement to change the light source from a deactivated state (i. e. , emitting no or negligible light or drawing no or negligible power) to an activated state (i.e. , emitting light). Thus, the activation time is a desired “light on” time for the corresponding light source.

[0091] In the context of the present disclosure, a light source of considered to draw negligible power when it is not intended to emit light. In such circumstances, it is possible that the light source may still draw current (e.g., due to leakage current), but this power draw should be considered negligible. As a working example, a current may be considered to be negligible if it is less than 0.5% of a current drawn by the light source when emitting light at its maximum intensity.

[0092] Similarly, in the context of the present disclosure, the term "negligible light" may refer to an intensity of light emitted from a light source that is so low that is imperceptible to the human eye and / or is less than 0.5% of a maximum possible intensity of light emitted by the light source (preferably less than 0,1% of this maximum possible intensity).

[0093] As a working example, the activation information may comprise a plurality of data entries, each data entry identifying an identity of at least one light source and a corresponding activation time. For instance, in some examples, sets of one or more lights sources have a shared activation time, which may be indicated in the activation information.

[0094] Table 2 provides an illustrative example of a portion of activation information. Table headings are provided for clarity, and may be omitted in practice.

[0095] Light Source ID Activation Time

[0096] 1 2024-04-11 15:43:30

[0097] 2 2024-04-11 16:40:26

[0098] 3, 4 2024-04-11 16:51:54

[0099] TABLE 2

[0100] The activation information may be generated by the control arrangement, e.g., as it manages the light installation. By way of example, the control arrangement may maintain a log of its actions, including the times at which it sends activation requests to each light source. This log may serve as the basis for the activation information.2024PF80381

[0101] 11

[0102] In particular, when the control arrangement sends a command or request to activate a particular light source, it may record the identity of the light source and the timestamp of the activation request in its log. This logging process may occur in real-time as the control arrangement operates the light installation.

[0103] As another example, the control arrangement may generate the activation information based on a predetermined schedule. For instance, if the light installation is programmed to activate certain light sources at specific times (e.g., at sunset), the control arrangement may generate the activation information in advance based on this schedule.

[0104] The activation information may also be updated dynamically if there are changes to the planned activation times. For example, if the control arrangement receives input from light sensors or other environmental monitoring devices, it may adjust activation times accordingly and update the activation information.

[0105] It will be appreciated that the control arrangement may store the activation information in a database or other storage module.

[0106] Figure 2 illustrates a computer-implemented method 200 for identifying first light sources amongst the plurality of light sources. Each first light source is a is a misbehaving light source of a first type.

[0107] As will be later explained, the computer-implemented method may be performed by a processing system, e.g., in communication with the plurality of light sources.

[0108] The method 200 comprises a step 210 of obtaining power information. The power information may, for instance, be retrieved from a central server (e.g., the control arrangement) or database / memory in communication with the control arrangement.

[0109] The method 200 comprises a step 220 of obtaining activation information. The activation information may be retrieved from the control arrangement (that generates any activation request) and / or a central server such as a database or memory in communication with the control arrangement.

[0110] The method 200 comprises a step 230 of processing the power information and the activation information to identify any first light sources in the plurality of light source.

[0111] A first light source is defined as a light source for which the power information indicates that a set of one or more first power change times for said light source each occurs no more than a first predetermined period of time after any activation time for said light source; and the power information indicates that at least one second power change2024PF80381

[0112] 12

[0113] time for said light source occurs approximately a second predetermined period of time after any of the set of one or more first power change times.

[0114] The first predetermined time period effectively defines a time period during which a power down is considered to result from an error or shut down of the driver arrangement for the light source in the immediate vicinity of a request to activate the light source. This may indicate that there has been an inrush current and / or voltage volatility of the power drawn by the driver arrangement during activation of the light source.

[0115] The first predetermined time period may be no greater than 2 hours, e.g., no greater than 1 hour. It can be expected that power cycles outside of a period of 2 hours after an activation request are unlikely to result from inrush current and / or voltage volatility of the power supply for the light source(s).

[0116] In this context, a second power change time is considered to occur approximately a second predetermined period of time after a first power change time when a magnitude of the difference between the second power change time and the first power change time is within a predetermined error margin of the second predetermined period of time. This criterion is met when the following equation is true:

[0117] (PCT2- PCT = PD2± 0.1PD2« PD2(1)

[0118] where PCT2 is the second power change time, PCTi is the first power change time and PD2 is the second predetermined period of time. Equation (1) can be restructured as:

[0119] |(PCT2— PCTi) — PD2| < 0.1PD2(2)

[0120] The second predetermined time period effectively defines a time period at which the driver arrangement is expected to recover and / or restart after a shut down due to inrush current and / or voltage volatility. Thus, the second predetermined time period may be an expected time period for the driver arrangement for the / each light source to restart after a shut down due to inrush current and / or voltage volatility.

[0121] A typical driver arrangement for a light source will have a fixed time period after shutting down (due to abnormal current / voltage conditions, such as an inrush current and / or voltage volatility of a mains supply). In particular, in such a scenario, the driver arrangement may enter a protection mode and have a fixed time period (after shutting down) before restarting.2024PF80381

[0122] 13

[0123] As a working example, a restart time of an example driver arrangement (for a light source) operating in a protection mode may be around 3 minutes (180 seconds). Thus, a suitable example value for the second predetermined time period is 3 minutes, at least for use with such driver arrangements. Other suitable time periods will be apparent dependent upon the specific use case scenario and / or driver arrangement(s) employed.

[0124] Step 230 may be performed by performing a separate identification process 240 for each light source. Different iterations of the identification process may be performed in parallel and / or sequentially, e.g., dependent upon the capabilities of the system performing method 200.

[0125] The identification process 240 may comprise a sub-step 241 of processing the activation information to identify, for the corresponding light source, any activation times.

[0126] The identification process 240 may then perform a sub-step 242 of processing the power information to identify, for the corresponding light source, any first power change times for the light source that occur no more than a first predetermined period of time after any activation time for said light source. If any first power change times are identified in substep 242, the first power change time(s) form the set of one or more first power change times.

[0127] Sub-step 242 can be trivially performed by comparing each first power change time for the light source to the activation time(s) for the light source.

[0128] The identification process 240 may then perform a sub-step 243 of processing the power information to identify, for the corresponding light source, whether or not any second power change time occurs approximately a second predetermined period of time after any one of the set of one or more first power change times (if any is / are identified in sub-step 242), and therefore whether or not the light source is a first light source.

[0129] In particular, the light source is a light source only when step 243 indicates that at least one second power change time occurs approximately a second predetermined period of time after any one of the set of one or more first power change times.

[0130] This may be performed using, for instance, the approach set out by equation (l) or(2).

[0131] After each iteration of the identification process 240, step 230 may comprise a sub-step 250 of determining whether or not all light sources indicated in the activation information and / or power information have been processed. Responsive to a positive determination in sub-step 250 (i.e., all light sources have been processed), step 230 ends. Otherwise, the step 230 moves to a next light source (e.g., in a sub-step 255) and repeats the identification process 240.2024PF80381

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[0133] Although not illustrated in Figure 2, the method 200 may further comprise outputting identification information that identifies each first light source (e.g., using the light source identifiers or similar).

[0134] This step may comprise, for instance, storing the identification information in a database or memory, controlling an output user interface to provide a user-perceptible output representing the identification information (such as a visual representation of the identification information) and / or providing the identification information to another processing system for further processing and / or analysis.

[0135] Another optional procedure using the identification information is later described.

[0136] Figure 3 illustrates power change times for a plurality of light sources 301, 302, 303, 304 in a first scenario 310 and a second scenario 320. First power change times (i.e., a decrease in power provided to the light source) are indicated with crosses. Second power change times (i.e., an increase in power provided to the light source) are indicated with squares.

[0137] In the first scenario 310, no light source functions as a first light source. As such, when an activation request (indicated by a triangle) is made to each light source, said light source activates (i.e., has an increased power) and does not undergo any power cycles within the first predetermined period of time.

[0138] In the second scenario 320, a subset 301, 303 of the light sources 301, 302, 303, 304 function as a first light source. As such, when an activation request is made to each light source in said subset, said light source undergoes one or more power cycles within the first predetermined period of time (indicated with an arrow).

[0139] The present disclosure also recognizes that the power information is likely to contain data about power change events that result from other causes, such as failure of a light source and / or scheduled / watchdog resetting of the power arrangement(s). In other words, it is recognized that not all power change events result from a light source undergoing one or more power cycles after a request to be activated.

[0140] Put another way, the power information is likely to contain data for misbehaving light sources of a different type to the first type and / or behaving light sources.

[0141] Accordingly, it may be advantageous to configure step 210 to filter (out) any power change times that are attributable to other causes of modification(s) to the power provided to the light source. This reduces an amount of data needing to be separately2024PF80381

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[0143] processed, and reduces a risk of erroneous identification of any light sources having the first type of error.

[0144] Figure 4 illustrates an example approach for performing step 210. The step 210 may comprise a step 410 of obtaining initial power information. The initial power information indicates, for each of a plurality of light sources (e.g., of a light installation), any first or second power change times, and may be produced in a similar manner to the power information previously described.

[0145] The step 210 may also comprise a step 420 filtering the initial power information to remove reference to any first / second power change time that meets one or more predetermined criteria. Each of the one or more predetermined criteria represents a criterion that indicates that the corresponding power change time is attributed to another cause (other than a power cycle of the light source after a request to be activated).

[0146] Thus, where the initial power information comprises a respective data entry for each power change event, then step 420 may comprise deleting or discarding the data entry carrying the first / second power change time that meets the one or more predetermined criteria.

[0147] This filtering step helps to focus the subsequent analysis on light sources that are more likely to exhibit the specific behavior of interest - namely, power cycling immediately after activation due to inrush current or voltage volatility issues.

[0148] A number of example criteria for the one or more predetermined criteria are hereafter described. The one or more predetermined criteria may include any one or more of these example criteria.

[0149] A first predetermined criterion is that the first / second power change time is a power change time for a light source associated with power change times distributed across a predetermined window of time.

[0150] This first predetermined criterion aims to identify and filter out power change times that are associated with faulty light sources, which are more susceptible to arbitrary power down and / or power cycling. For instance, erratic power fluctuations in a light source could be caused by various issues, such as intermittent electrical connections; failing components within the light source or its driver arrangement; or the like.

[0151] The predetermined window of time for this first predetermined criterion should be long enough to capture recurring patterns of erratic behavior. For instance, a window of 24 hours or a window representing an expected prior of activation time (e.g., a2024PF80381

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[0153] time between sunset and sunrise) might be appropriate for many outdoor lighting installations.

[0154] One possible approach for determining whether or not a power change time meets the first predetermined criterion is hereafter described. Initially, all power change times may be grouped by light source. Subsequently, for each light source, the number of power changes (e.g., the number of first / second power change times) within the predetermined window is calculated. Subsequently, for each light source, this count is compared to a threshold value. If the count for a light source exceeds this threshold value, then all power change times for said light source may be determined to meet the first predetermined criterion (i.e., and subsequently filtered out).

[0155] Another set of possible predetermined criteria are each met when the first / second power change time is a power change time resulting from a particular predefined or known reboot of the driver arrangement, which is / are not attributable to a power cycle due to an inrush current and / or voltage volatility. Although a number of examples are hereafter described, the skilled person will appreciate that the precise criteria (and / or values used for the criteria) may vary dependent upon the specific type and topology of the driver arrangement and / or control scheme employed by the driver arrangement.

[0156] For instance, a second predetermined criterion may be that the first / second power change time is a first power change time for a light source that occurs no earlier than a third predetermined period of time before a second power change time for the same light source.

[0157] The third predetermined period of time is less than the second predetermined period of time, e.g., more than 4 times smaller. In particular, the third predetermined period of time may be less than or equal to 5 seconds, e.g., less than or equal to 3 seconds, e.g., 1 second.

[0158] A first power change time that meets the second predetermined criterion effectively represents a first power change time that occurs as a result of a different cause of the reboot to the driver arrangement than a power cycle (resulting from a supply volatility at an activation time). For instance, a so-called “watchdog” reboot of the driver arrangement is expected to have a very short downtime (typically less than a second). Similarly, some forms of software reboot for a processor of a driver arrangement are expected to have a very short downtime for the driver arrangement.2024PF80381

[0159] 17

[0160] In this way, the second predetermined criterion aims to help filter out power changes that are part of normal operation or planned maintenance, rather than indicative of a problem with the light source's response to activation.

[0161] "Watchdog" reboots are a common feature in embedded systems, including driver arrangements for light sources. They serve as a fail-safe mechanism, automatically restarting the system if it becomes unresponsive or enters an unexpected state. These reboots are designed to be quick, typically lasting less than a second, to minimize disruption to the light source's operation.

[0162] Similarly, software reboots for a processor in the driver arrangement may occur for various reasons, such as clearing memory or resetting after error conditions. Like watchdog reboots, these are generally designed to be brief to maintain system reliability and minimize downtime.

[0163] By filtering out these short-duration power changes, the method is able to focus upon identifying light sources that indicate issues with inrush current or voltage volatility upon light source activation.

[0164] Similarly, a third predetermined criterion may be that the first / second power change time is a second power change time for a light source that occurs no later than the third predetermined period of time after a first power change time for the same light source.

[0165] This effectively recognizes the same principle as the second predetermined criterion, but from the perspective of the second power change times. Thus, whilst the second predetermined criterion focuses on identifying short-duration power-down events (first power change times), this third predetermined criterion identifies the corresponding power-up events (second power change times).

[0166] If employed together, the second and third predetermined criteria form a robust filter for short-duration power cycles, allowing the subsequent analysis to focus more effectively on identifying light sources that exhibit problematic behavior specifically related to activation attempts.

[0167] As another example, a fourth predetermined criterion may be that the first / second power change time is a first power change time for a light source that occurs between a fourth predetermined period of time and a fifth predetermined period of time before a second power change time for the same light source.

[0168] The fourth predetermined period of time and the fifth predetermined period of time are both smaller than the second predetermined period of time, at least 3 times smaller.2024PF80381

[0169] 18

[0170] A first power change time that meets the fourth predetermined criterion also effectively represents a first power change time that occurs as a result of a different cause of the reboot to the driver arrangement than a power cycle resulting from a supply volatility at an activation time. In particular, some forms of software reboot may take a longer period of time to reset the driver arrangement, but significantly less time than for a reset of the driver arrangement in a protected mode (e.g., due to supply volatility).

[0171] By way of working example, the fourth predetermined period of time may take a value between 10 and 20 seconds, e.g., 17 seconds. The fifth predetermined period of time may take a value between 20 and 30 seconds, e.g., 24 seconds.

[0172] Similarly, a fifth predetermined criterion may be that the first / second power change time is a second power change time for a light source that occurs between the fourth predetermined period of time and the fifth predetermined period of time after a first power change time for the same light source.

[0173] This fifth predetermined criterion is complementary to the fourth predetermined criterion, focusing on the power-up events (second power change times) that correspond to the power-down events identified by the fourth criterion. Thus, the fifth predetermined criterion effectively recognizes the same principle as the fourth predetermined criterion, but from the perspective of the second power change times.

[0174] If employed together, the fourth and fifth predetermined criteria form a robust filter for short-duration power cycles resulting from known or expected driver arrangement resets, allowing the subsequent analysis to focus more effectively on identifying light sources that exhibit problematic behavior specifically related to activation attempts.

[0175] A sixth predetermined criterion may be that the first / second power change time is a power change time for a light source that occurs within a predetermined test time window relative to a scheduled maintenance or testing event for that light source.

[0176] This sixth predetermined criterion aims to filter out first / second power change times that are associated with or result from planned maintenance or testing activities, rather than indicative of problematic behavior in the light source or its driver arrangement.

[0177] Scheduled maintenance and testing events may involve intentional power cycling or adjustments to the light sources.

[0178] By identifying and excluding power change times that occur within a specific time window around these scheduled events, the method can more accurately focus on identifying light sources that exhibit unexpected or problematic behavior related to activation attempts and inrush current or voltage volatility issues.2024PF80381

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[0180] The predetermined test time window for the sixth predetermined criterion may be chosen to adequately cover the duration of typical maintenance or testing procedures. For example, it might be set to a test period before and after the scheduled event, such as 30 minutes on either side. This window allows for any power change times that occur as a result of power fluctuations during the setup, execution, and completion of the maintenance or testing activities to be filtered out.

[0181] Of course, identifying whether a power change time meets the sixth predetermined criteria requires access to a schedule of maintenance and testing events for each light source. This schedule could be maintained within the control arrangement or in a separate database accessible to the system performing the analysis.

[0182] As such, in some examples, step 420 may comprise obtaining schedule information identifying any maintenance and / or testing times for each light source. Step 420 may comprise processing the schedule information and the power information to identify any first / second power change times that meet the sixth predetermined criterion.

[0183] A seventh predetermined criterion may be that the first / second power change time is a power change time for a light source that occurs within a predetermined environmental time window of a known environmental event. Such environmental events may include severe weather conditions, power grid fluctuations, or other external factors that could affect the operation of light sources.

[0184] For instance, the predetermined time window may be set to a period before and after an environmental event (such as a power surge) that is predicted to affect the light source(s). This criterion helps filter out power change times that may be caused by these environmental factors rather than issues with the light source or its driver arrangement.

[0185] As a working example, the predetermined environmental time window may be set to 15 or 30 minutes before and after the environmental event. Other suitable example lengths for the predetermined time window will be readily apparent to the skilled person.

[0186] To implement the seventh predetermined criterion, step 420 may comprise obtaining environmental data identifying a time at which any environmental event takes place. This environmental data may be retrieved, for instance, from a monitoring system such as a power grid monitoring system. Step 420 may comprise processing the environmental data and the power information to identify any first / second power change time that meets the seventh predetermined criterion.2024PF80381

[0187] 20

[0188] The above examples of predetermined criteria are non-exhaustive, and the skilled person would readily identify other suitable examples of predetermined criteria that will be apparent to the skilled person.

[0189] Figure 5 illustrates a computer-implemented method 500 according to some examples.

[0190] The method 500 comprises performing the method 200 (Figure 2) to identify any first light sources amongst the plurality of light sources.

[0191] The method 500 further comprises a step 520 of defining a future activation time for each first light source, wherein a separation between future activation times of first light source is no less than an expected time for a driver arrangement for powering each first light source to restart following an abnormal voltage or current supply condition (“expected restart time”), e.g., 3 minutes. This expected restart time may, for instance, be the restart time of a driver arrangement (for a light source) operating in a protection mode.

[0192] Thus, step 520 comprises defining a future activation time for each first light source to be no less than the expected restart time before the future activation time of any other first light source; and no less than the expected after the future activation time of any other first light source.

[0193] In this way, the future activation time(s) of any first light sources are staggered with respect to one another. This significantly reduces the likelihood of multiple first light sources being activated simultaneously or in close succession. By implementing this staggered activation approach, the method 500 addresses the root cause of the problematic behavior exhibited by first light sources.

[0194] Specifically, the 3-minute minimum separation between activation times helps mitigate the risk of inrush current and voltage volatility issues that can occur when multiple light sources are activated at or near the same time. It is recognized that this separation allows the power supply and electrical infrastructure to stabilize between each first light source activation, reducing the chances of supply volatility triggering the protective shutdown and restart cycle in the driver arrangements of these sensitive light sources.

[0195] In some examples, the minimum separation time between activation times for first light sources may be greater than the expected restart time. . For example, where the expected restart time is 3 minutes, the separation time may be no less than 5 minutes, or in some cases, no less than 10 minutes.

[0196] A longer separation time may allow for more complete stabilization of the power supply and electrical infrastructure between activations of different first light sources.2024PF80381

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[0198] This increased buffer may further reduce the chances of supply volatility issues, particularly in environments with less stable power grids or during periods of high electrical demand.

[0199] In some examples, the separation time between future activation times for first light sources (defined in step 520) may be a random or pseudo-random number of minutes, e.g., within a predetermined range. This randomization to the separation of the activation times may introduce variability into the activation sequence, which may help prevent predictable patterns that could potentially lead to recurring issues.

[0200] For example, the separation time determined in step 520 may be randomly selected from a range of 3 to 10 minutes. This randomization may be implemented using a pseudo-random number generator, with the generated value determining the specific separation time for each pair of consecutive first light source activations.

[0201] Of course, the method 500 may further comprise controlling the activation of the first light sources using the future activation time(s) identified in step 520.

[0202] The skilled person would be readily capable of developing a processing system for carrying out any herein described method. Thus, each step of the flow chart may represent a different action performed by a processing system, and may be performed by a respective module of the processing system.

[0203] The processing system may be communicatively connected to the light source(s) and / or the control arrangement, e.g., via one or more databases and / or other storage units. In some instances, the control arrangement comprises the processing system, i.e., the control arrangement may be configured to perform the steps of any herein disclosed method.

[0204] Embodiments may therefore make use of a processing system. The processing system can be implemented in numerous ways, with software and / or hardware, to perform the various functions required. A processor is one example of a processing system which employs one or more microprocessors that may be programmed using software (e.g., microcode) to perform the required functions. A processing system may however be implemented with or without employing a processor, and also may be implemented as a combination of dedicated hardware to perform some functions and a processor (e.g., one or more programmed microprocessors and associated circuitry) to perform other functions.

[0205] Examples of processing system components that may be employed in various embodiments of the present disclosure include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASICs), and field-programmable gate arrays (FPGAs).2024PF80381

[0206] 22

[0207] In various implementations, a processor or processing system may be associated with one or more storage media such as volatile and non-volatile computer memory such as RAM, PROM, EPROM, and EEPROM. The storage media may be encoded with one or more programs that, when executed on one or more processors and / or processing systems, perform the required functions. Various storage media may be fixed within a processor or processing system or may be transportable, such that the one or more programs stored thereon can be loaded into a processor or processing system.

[0208] It will be understood that disclosed methods are preferably computer-implemented methods. As such, there is also proposed the concept of a computer program comprising code means for implementing any described method when said program is run on a processing system, such as a computer. Thus, different portions, lines or blocks of code of a computer program according to an embodiment may be executed by a processing system or computer to perform any herein described method.

[0209] There is also proposed a non-transitory storage medium that stores or carries a computer program or computer code that, when executed by a processing system, causes the processing system to carry out any herein described method.

[0210] In some alternative implementations, the functions noted in the block diagram(s) or flow chart(s) may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.

[0211] Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0212] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. If the term "adapted to" is used in the claims or description, it is noted the term "adapted to" is intended to be equivalent to the term "configured to". If the term "arrangement" is used in the claims or description, it is noted the term "arrangement" is intended to be equivalent to the term "system", and vice versa.

[0213] A single processor or other unit may fulfill the functions of several items recited in the claims. If a computer program is discussed above, it may be stored / distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied2024PF80381

[0214] 23

[0215] together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.

[0216] Any reference signs in the claims should not be construed as limiting the scope.

Claims

2024PF8038124CLAIMS:

1. A computer-implemented method (200, 500) for identifying first light sources amongst a plurality of light sources, the computer- implemented method comprising:obtaining (210) power information indicating, for each light source of the plurality of light sources (301, 302, 303, 304):any first power change times, wherein a first power change time is a time at which there is a decrease in power provided to said light source; andany second power change times, wherein a second power change time is a time at which there is an increase in power provided to said light source;obtaining (220) activation information indicating, for each light source of the plurality of lights sources, any activation times for said light source, wherein an activation time is a time at which a control arrangement requests said light source to change from a deactivated state, in which the light source draws no or negligible power, to an activated state in which the light source draws power;processing (230) the power information and the activation information to identify first light sources (301, 303) in the plurality of light sources, wherein a first light source is a light source for which:the power information indicates that a set of one or more first power change times for said light source each occurs no more than a first predetermined period of time after any activation time for said light source; andthe power information indicates that at least one second power change time for said light source occurs approximately a second predetermined period of time after any of the set of one or more first power change times.

2. The computer-implemented method of claim 1, wherein, for each light source, the second predetermined period of time is an expected time taken for a driver arrangement for powering said light source to restart.

3. The computer-implemented method of claim 1 or 2, wherein, for each light source, at least one second power change time occurs approximately the second2024PF8038125predetermined period of time after any first power change time when the difference between at least one second power change time and any first power change time is within a predetermined error margin of the second predetermined period of time.

4. The computer-implemented method of claim 3, wherein the predetermined error margin is no more than 10% of the second predetermined period of time.

5. The computer-implemented method of any one of claims 1 to 4, wherein the power information comprises a plurality of data entries, each data entry identifying: an identity of one of the plurality of light sources; a power change time for the identified light source; and information indicating whether the power change for the identified light source increases or decreases a power provided to the light source.

6. The computer-implemented method of any of claims 1 to 5, wherein the step (210) of obtaining power information comprises:obtaining (410) initial power information indicating, for each of the plurality of light sources:any first power change times, wherein a first power change time is a time at which there is a decrease in power provided to said light source; andany second power change times, wherein a second power change time is a time at which there is an increase in power provided to said light source; and producing the power information by filtering (420) the initial power information to remove reference to any first power change time and second power change time that meets one or more predetermined criteria.

7. The computer-implemented method of claim 6, wherein the one or more predetermined criteria includes a first predetermined criterion that the first power change time or second power change time is a power change time for a light source associated with power change times distributed across a predetermined window of time.

8. The computer-implemented method of claim 7, wherein the first predetermined criterion is that the first power change time or second power change time is a power change time for a light source having more than a predetermined number of first and / or second power change times within the predetermined window of time.2024PF80381269. The computer-implemented method of any one of claims 6 to 8, wherein:the one or more predetermined criteria include a second predetermined criterion that a first power change time for a light source occurs no earlier than a third predetermined period of time before a second power change time for the same light source; andthe third predetermined period of time is less than the second predetermined period of time.

10. The computer-implemented method of claim 9, wherein the third predetermined period of time is no greater than 5 seconds.

11. The computer-implemented method of any one of claims 9 or 10, wherein:the one or more predetermined criteria includes a third predetermined criterion that a second power change time for a light source occurs no later than the third predetermined period of time after a first power change time for the same light source.

12. The computer-implemented method of any one of claims 6 to 8, wherein:the one or more predetermined criteria includes a fourth predetermined criterion that a first power change time for a light source occurs between a fourth predetermined period of time and a fifth predetermined period of time before a second power change time for the same light source;the one or more predetermined criteria includes a fifth predetermined criterion that a second power change time for a light source occurs between the fourth predetermined period of time and the fifth predetermined period of time after a first power change time for the same light source;the fourth predetermined period of time is less than the second predetermined period of time; andthe fifth predetermined period of time is less than the second predetermined period of time.

13. The computer-implemented method (500) of any one of claims 1 to 12, further comprising defining (520) a future activation time for each first light source, wherein a separation between future activation times of each first light source is no less than an2024PF8038127expected time for a driver arrangement for powering each first light source to restart following an abnormal voltage or current supply condition.

14. A computer program product comprising computer program code means which, when executed on a computing device having a processing system, cause the processing system to perform all of the steps of the method according to any one of claims 1 to 13.

15. A processing system configured to identify first light sources amongst a plurality of light sources, wherein the processing system is configured to:obtain (210) power information indicating, for each light source of the plurality of light sources (301, 302, 303, 304):any first power change times, wherein a first power change time is a time at which there is a decrease in power provided to said light source; andany second power change times, wherein a second power change time is a time at which there is an increase in power provided to said light source;obtain (220) activation information indicating, for each light source of the plurality of lights sources, any activation times for said light source, wherein an activation time is a time at which a control arrangement requests said light source to change from a deactivated state, in which the light source draws no or negligible power, to an activated state in which the light source draws power;process (230) the power information and the activation information to identify first light sources (301, 303) in the plurality of light sources, wherein a first light source is a light source for which:the power information indicates that a set of one or more first power change times for said light source each occurs no more than a first predetermined period of time after any activation time for said light source; andthe power information indicates that at least one second power change time for said light source occurs approximately a second predetermined period of time after any of the set of one or more first power change times.

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