Patent Description:
Contemporary aircraft include systems that typically need to exchange data between the systems on the aircraft and operators located on the ground for maintenance, operational, and other purposes. WiFi (RTM) and datalink services are currently used to exchange such data. These services are useful in that they provide for communication over a relatively great distance, from an airport-wide perspective. However, this benefit is also a detriment in that the communications may be more easily intercepted, which may not always be desirable, regardless of whether the data is encrypted or not. Moreover, these communication services require relatively-heavy, dedicated hardware be installed on the aircraft. As both WiFi (RTM) and datalink services require equipment and/or antennas to be located in the aircraft these services lead to additional weight and an increase in the cost of operation.

Contemporary aircraft cockpits include a flight deck having multiple flight displays, which may display to the flight crew or ground technicians a wide range of information. However contemporary aircraft include systems and components that are routinely examined by ground technicians for status, upkeep, maintenance and repair purposes and are not located adjacent the flight deck.

<CIT> discloses a method of indicating a status of a device on an aircraft in which a device on an aircraft is monitored to detect a fault or other change of status of the device in response to which a light source is operated to provide a telltale status indication which can be discerned by a human, status information related to the change of status is also generated, a portable receiver is moved into proximity with the light source, and the light source is operated to transmit the status information to the portable receiver via free space by means of modulated light which is modulated with the status information. <CIT> discloses a dongle with light sensor and audio jack plug suitable for receiving diagnostic data from a flashing LED on an appliance. <CIT> discloses a free-space optical communications system for transmitting data between an aircraft computer system and a ground-based computer system.

An aspect of the present disclosure relates to an avionics component maintenance system, including a light assembly provided on an aircraft, the light assembly configured to provide an output indicative of a status of an avionics component on the aircraft and a mobile device having a display and an optical sensor and configured to determine light emitted from the light assembly, and determine the status of the avionics component to define a determined status based on the determined light emitted, and provide on the display an action for a user related to the avionics component based on the determined status. A communication range between the light assembly and the mobile device can be adjusted by regulating at least one of brightness or divergence, so as to require the mobile device to be in sufficiently close proximity to the light assembly to determine the light emitted from the light assembly.

Another aspect of the present disclosure includes a method of avionics maintenance, the method including determining, via an optical sensor on a mobile device, light emitted from a light assembly at an avionics component, wherein a communication range between the light assembly and the mobile device can be adjusted by regulating at least one of brightness or divergence, so as to require the mobile device to be in sufficiently close proximity to the light assembly to determine the light emitted from the light assembly, determining, via a maintenance module on the mobile device, the status of the component based on the light emitted to define a determined status, and providing, on a display of the mobile device, an action for a user related to the determined status of the component.

The described aspects of the present disclosure are directed to a component management system or a component maintenance system that is illustrated and described in an exemplary environment of an aircraft. However, the disclosure is not so limited and can have general applicability in non-aircraft applications, such as other mobile applications and non-mobile industrial, commercial, and residential applications.

As used herein, it will be understood that "a set" of elements can include any number of the respective elements, including only one element. Also as used herein, while sensors can be described as "sensing" or "measuring" a respective value, sensing or measuring can include determining a value indicative of or related to the respective value, rather than directly sensing or measuring the value itself. The sensed or measured values can further be provided to additional components. For instance, the value can be provided to a controller module or processor, and the controller module or processor can perform processing on the value to determine a representative value or an electrical characteristic representative of said value.

As used herein, a "controller" can include at least one processor and memory. Non-limiting examples of the memory can include Random Access Memory (RAM), Read-Only Memory (ROM), flash memory, or one or more different types of portable electronic memory, such as discs, DVDs, CD-ROMs, etc., or any suitable combination of these types of memory. The processor can be configured to run any suitable programs or executable instructions designed to carry out various methods, functionality, processing tasks, calculations, or the like, to enable or achieve the technical operations or operations described herein. The program can include a computer program product that can include machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media, which can be accessed by a general purpose or special purpose computer or other machine with a processor. Generally, such a computer program can include routines, programs, objects, components, data structures, algorithms, etc., that have the technical effect of performing particular tasks or implement particular abstract data types.

Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and can include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other.

<FIG> schematically illustrates an aircraft <NUM> that may utilize a component maintenance system according to aspects of the present disclosure. While components on a commercial aircraft have been illustrated, it is contemplated that embodiments of the invention may be used with any type of components including non-vehicle components. Further, embodiments of the invention can be utilized with both mechanical structures as well as all other equipment. The environment of the aircraft <NUM> will be described for explanatory purposes only.

One or more propulsion engines <NUM> may be coupled to a fuselage <NUM>, a cockpit <NUM> may be positioned in the fuselage <NUM>, and wing assemblies <NUM> may extend outward from the fuselage <NUM>. A plurality of aircraft systems and components <NUM> that enable proper operation of the aircraft <NUM> may be included as well as a flight control computer or computer <NUM>.

The plurality of aircraft systems and components <NUM> may reside within the cockpit <NUM>, within the electronics and equipment bay <NUM>, or in other locations throughout the aircraft <NUM> including that they may be associated with the engines <NUM>, wing assemblies <NUM>, or landing gear <NUM>. Such aircraft systems and components <NUM> may include but are not limited to: an electrical system, an oxygen system, hydraulics and/or pneumatics system, a fuel system, a propulsion system, navigation systems, flight controls, audio/video systems, an Integrated Vehicle Health Management (IVHM) system, and systems and components associated with the mechanical structure of the aircraft <NUM> including flaps. A variety of aircraft systems and components <NUM> have been illustrated for exemplary purposes and it will be understood that they are only a few of the systems and components that may be included in the aircraft <NUM>. A data network <NUM> over which the plurality of aircraft systems and components <NUM> may communicate with each other and provide information to a crew of the aircraft <NUM> may be included. For example, the aircraft systems and components <NUM> may output various information to a flight deck <NUM> located in a cockpit <NUM> of the aircraft <NUM>.

For ease of explanation, the remainder of the application will focus on a component <NUM> in the form of an electrical power system <NUM> located in the electronics and equipment bay <NUM> of the aircraft <NUM>. As more clearly shown in <FIG>, the electrical power system <NUM> includes a cabinet <NUM> with doors <NUM>. When the doors <NUM> are closed visual communication between the electrical power system <NUM> and maintenance personnel stops.

A component maintenance system <NUM> as contemplated by aspects of the present disclosure can be utilized with any of the above-described systems or components, including the specific exemplary electrical power system <NUM>. It is contemplated that the component maintenance system <NUM> can be most beneficial for use with a component or system that: (i) has some processing power, (ii) performs self-tests, (iii) is without a human-machine interface like a display or buttons, (iv) and is outside the cockpit. It will be understood that benefits can still be achieved by utilizing the component maintenance system <NUM> with a system or component having some subset of these features.

A light assembly <NUM> may be provided on the electrical power system <NUM>, in this case on an exterior portion of one of the doors <NUM>. By way of non-limiting example, the light assembly can include an illuminable portion <NUM>. The illuminable portion <NUM> can include, but is not limited to, at least one visual light source such as an incandescent light or LEDs operably coupled to the door <NUM>, mounted to the door <NUM>, or disposed behind a transparent surface of the door <NUM>. The illuminable portion <NUM> is not limited to the positions and implementations as shown. For example the illuminable portion <NUM> can be mounted on an interior surface such that the doors <NUM> need to be opened in order to allow visual communication with the illuminable portion. This has the added benefit of being more secure because when the doors <NUM> are closed visual communication between the electrical power system <NUM> and the maintenance personnel stops.

It should be appreciated that the illuminable portion <NUM> can include any number of lights including a single light. Additionally, the illuminable portion <NUM> can be different colors, such as a grouping of different color LEDs selectively operable to illustrate multiple colors or having a same color with a variable brightness. The illuminable portion <NUM> can also include a simple status light.

The light assembly <NUM> can be operably coupled to a control module <NUM> or other portion of the electrical power system <NUM> configured to output a control signal to the light assembly <NUM> such that the light assembly is configured to provide a light output indicative of a status of the electrical power system <NUM>. More specifically, the illuminable portion <NUM> can be modulated by the control module <NUM> to form a visual light communication data link in order to transmit data. Including, but not limited to, that the modulated light can be in the visual part of the electromagnetic spectrum (wavelength <NUM>-<NUM>). As the illuminable portion <NUM> can be modulated in any suitable manner it can allow any type of data to be transmitted.

The control module <NUM> may include a memory in which is stored a component data file containing at least a component identifier light set as well as executable instructions for modulation a light output corresponding to other statuses of the component. It will be understood that any suitable data may be transmitted including a manufacturing date, prior maintenance information, user manual, section of a user manual, failure of a self-test, passing of a self-test, operation information of the component, etc. It is contemplated that the control module <NUM> may be operably coupled to any suitable portion of the electrical power system <NUM> in any suitable manner.

A mobile device <NUM> is included in the component maintenance system <NUM> and is configured to communicate with the light assembly <NUM> utilizing light. The mobile device <NUM> may be operated by a user <NUM> such that the mobile device <NUM> may be capable of interfacing with the electrical power system <NUM>. A display <NUM> may be included in the mobile device <NUM>. It is contemplated that the display <NUM> may be a touch screen <NUM>, although this need not be the case, such that the user <NUM> may interact with the display <NUM> through the touch screen <NUM>. While the mobile device <NUM> has been illustrated as a phone having a touch screen <NUM> it will be understood that the handheld device may be a scanner, PDA, tablet PC, or any other suitable type of mobile device. A keyboard or cursor control may also be provided in the mobile device <NUM> to allow for user interaction with the display <NUM>.

In order to be capable of wirelessly linking with other systems and devices, the mobile device <NUM> may also include any suitable wireless communication link <NUM>, which may include, but is not limited to, packet radio, satellite uplink, Wireless Fidelity (WiFi) (RTM), WiMax (RTM), AeroMACS (RTM), Bluetooth (RTM), ZigBee (RTM), <NUM> (RTM) wireless signal, code division multiple access (CDMA) wireless signal, global system for mobile communication (GSM) (RTM), <NUM> (RTM) wireless signal, long term evolution (LTE) signal, Ethernet, or any combinations thereof. It will also be understood that the particular type or mode of wireless communication is not critical to embodiments of this invention, and later-developed wireless networks are certainly contemplated as within the scope of embodiments of this invention.

A controller <NUM> may be included in the mobile device <NUM> and may be operably coupled to components of the mobile device <NUM> including the display <NUM>, touch screen <NUM>, a sensor <NUM>, and wireless communication link <NUM>. The controller <NUM> may include any suitable memory and processing units, which may be running any suitable programs to implement a graphical user interface (GUI) and operating system.

The sensor <NUM> may be located in any suitable location on the mobile device <NUM> so that data communicated by the light assembly <NUM> can be detected. In one example, the sensor <NUM> can determine an intensity of light output by the light assembly <NUM>. Exemplary sensor(s) <NUM> can include any optical sensor capable of capturing light intensity such as a camera. One suitable type of camera may be a CMOS camera. Other exemplary imaging devices include a CCD camera, a digital camera, a video camera, or any other type of device capable of determining light intensity output by the illuminable portion <NUM>. That camera may capture either or both visible and non-visible radiation. For example, the camera may capture intensity of both visible light and non-visible light, such as ultraviolet light. In yet another example, the sensor <NUM> may be a thermal device capable of detecting radiation in the infrared region of the electromagnetic spectrum. The sensor(s) <NUM> may be located on either a front or rear side of the mobile device <NUM>.

The mobile device <NUM> can include a computer program or component maintenance application having an executable instruction set for exchanging information when the mobile device <NUM> senses light from the light assembly <NUM>. The component maintenance application may include an applications, software program, computer program product, etc. that may include machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media may be any available media, which can be accessed by a general purpose or special purpose computer or other machine with a processor. Generally, such a computer program may include routines, programs, objects, components, data structures, algorithms, etc. that have the technical effect of performing particular tasks or implement particular abstract data types. Machine-executable instructions, associated data structures, and programs represent examples of program code for executing the exchange of information as disclosed herein. Machine-executable instructions may include, for example, instructions and data, which cause a general-purpose computer, special-purpose computer, or special-purpose processing machine to perform a certain function or group of functions.

<FIG> further illustrates that the component maintenance system <NUM> may also include a computer <NUM>, other than the mobile device <NUM> and that is remote from the mobile device <NUM> and may be in wireless communication with the mobile device <NUM> and/or the aircraft <NUM>. It is contemplated that the computer <NUM> may be remote from the mobile device <NUM> and the aircraft <NUM>. For example, the computer <NUM> may be located at airline central maintenance, airline control, remote processing center, a manufacturer's database location, etc. The computer <NUM> may include any suitable wireless communication link <NUM> capable of wirelessly linking with other systems and devices. The computer <NUM> may be directly coupled with the wireless communication link <NUM> or may be indirectly coupled to the wireless communication link <NUM> through a secondary communication link <NUM>, which may include an internet connection to couple the computer <NUM> to the wireless communication link <NUM>.

The mobile device <NUM> may allow a user to access or read a user manual or maintenance manual for the system or component having the light assembly <NUM>, in this case the electrical power system <NUM>. The mobile device <NUM> may also be configured to couple to a remote processing center and the component maintenance application may automatically provide information thereto. The mobile device can further couple to a manufacturer's database to provide information on the mobile device related to manufacturing information, repair information, or inventory information related to the component.

It is contemplated that the wireless communication link <NUM> of the mobile device <NUM> may include a secure wireless communication system that may be in communication with a secure wireless communication system of the computer <NUM> to establish a secure communication. In this manner, the mobile device <NUM> may securely wirelessly communicate with other systems such as airline central maintenance or airline control, a remote processing center, and/or a manufacturer's database. The secure communication between the computer <NUM> and the mobile device <NUM> may be performed after one of the computer <NUM> and the mobile device <NUM> recognizes the other of the computer <NUM> and the mobile device <NUM> to provide for a secure communication.

During operation, the sensor <NUM> of the mobile device <NUM> is utilized to determine light emitted from the light assembly <NUM>. The mobile device <NUM> may require close proximity to the light assembly <NUM>. Such a close proximity makes the light assembly <NUM> more secure because it is difficult for unauthorized personnel to be that near a component of the aircraft. It is contemplated that a communication range between the component and the mobile device <NUM> can be adjusted by regulating at least one of brightness of the light assembly <NUM> or divergence of the sensor <NUM>. That is, the lower the brightness, the nearer the mobile device <NUM> has to be to the component <NUM> in order to receive data.

More specifically, in an instance where the illuminable portion <NUM> is an LED the constant current of electricity supplied to illuminable portion <NUM> can be dipped and dimmed, up and down at extremely high speeds, by the control module <NUM>. The sensor <NUM> can detect such changes without those changes being visible to the human eye, although they can be. In this manner, data is fed into illuminable portion <NUM> with signal processing technology from the control module <NUM> and the illuminable portion <NUM> then sends data embedded in its beam at rapid speeds to the sensor <NUM>, which can be as simple as a photodiode. The tiny changes in the rapid dimming or on and off of the illuminable portion <NUM> is then converted by the sensor <NUM> into electrical signals, from which the status of the component (and a myriad of other information) can be determined.

The controller <NUM> may use the sensed emitted light in the visual light communication data link to determine a status of the component. Alternatively, it is contemplated that an application on the mobile device can analyze the emitted light in the visual light communication data link or video or determine the status of the component. Further still, it is contemplated that once information is transferred to the mobile device <NUM> that such information may be securely communicated to the computer <NUM>. The mobile device <NUM> may execute a program for transmitting data from the mobile device <NUM> to the computer <NUM>. It is contemplated that such a process may be user initiated or may be implemented automatically by the mobile device <NUM>. This may allow the information to be transferred to the computer <NUM> and the computer <NUM> can analyze the light emitted in the visual light communication data link or determine the status of the component.

It will be understood that details of environments that may implement embodiments of the invention are set forth in order to provide a thorough understanding of the technology described herein. It will be evident to one skilled in the art, however, that the exemplary embodiments may be practiced without these specific details and in alternative manners. The exemplary embodiments are described with reference to the drawings. These drawings illustrate certain details of specific embodiments that implement a module or method, or computer program product described herein. However, the drawings should not be construed as imposing any limitations that may be present in the drawings. The method and computer program product may be provided on any machine-readable media for accomplishing their operations. The embodiments may be implemented using an existing computer processor, or by a special purpose computer processor incorporated for this or another purpose, or by a hardwired system.

As noted above, embodiments described herein may include a computer program product comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media may be any available media, which may be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to carry or store desired program code in the form of machine-executable instructions or data structures and that may be accessed by a general purpose or special purpose computer or other machine with a processor. When information is transferred or provided over a network or another communication connection (either hardwired, wireless, or a combination of hardwired or wireless) to a machine, the machine properly views the connection as a machine-readable medium. Thus, any such a connection is properly termed a machine-readable medium. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions comprise, for example, instructions and data, which cause a general-purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions.

Embodiments will be described in the general context of method steps that may be implemented in one embodiment by a program product including machine-executable instructions, such as program codes, for example, in the form of program modules executed by machines in networked environments. Generally, program modules include routines, programs, objects, components, data structures, etc. that have the technical effect of performing particular tasks or implement particular abstract data types. Machine-executable instructions, associated data structures, and program modules represent examples of program codes for executing steps of the method disclosed herein. The particular sequence of such executable instructions or associated data structures represent examples of corresponding acts for implementing the functions described in such steps.

Embodiments may also be practiced in distributed computing environments where tasks are performed by local and remote processing devices that are linked (either by hardwired links, wireless links, or by a combination of hardwired or wireless links) through a communication network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.

In accordance with aspects of the present disclosure, <FIG> illustrates a method <NUM>, which may be used for avionics maintenance. Light is emitted, at <NUM>, from a light assembly <NUM> at an avionics component such as the previously described electrical power system <NUM>. At <NUM>, the sensor <NUM> on the mobile device <NUM> determines the light emitted, at <NUM>. For instance the sensor <NUM> receives the light emitted by visual light communication data link. At <NUM>, the status of the component is determined based on the emitted light to define a determined status of the component. The status can be any suitable status for the component including any error code, any repair code, any part information, any mechanical or electrical information, etc. For example, if a relay within the electrical power system <NUM> fails to close when commanded during flight then the information to be communicated could be: error code, repair code, repair steps including diagrams, relay identifier, phase of flight, state of other inputs/outputs and general state of system (including specific voltages, currents, other failures) at the time when this failure occurred. At <NUM>, the light is analyzed to determine a status of the component. More specifically, captured light intensity is determined (i.e. the illuminable portion <NUM> being modulated on/off to create a visual light communication data link).

It will be understood that any additional data can be communicated from the component <NUM> to the maintenance personnel via the visual light communication and the component maintenance system <NUM>. The light assembly <NUM> in the component <NUM> can transmit any information possible including statuses, operating conditions, historic performance, etc. The visual light communication data link provides essentially a 'free text' field to communicate to the mobile device <NUM> of the component maintenance system <NUM>. An unlimited amount of information can be relayed rather than a restrictive choice of a limited number of predetermined statuses.

At <NUM>, an action can be provided on a display <NUM> of the mobile device <NUM> for the maintenance personnel related to the component. The action can include, by way of non-limiting example, a maintenance action for the personnel to complete and which the user can then perform to fix the component or change the status of the component. The action provided can also or alternatively include repair information for the component, inventory information for the component, or a section of a user manual. For example, a copy of the user manual related to the component or a section of the user manual related to the component can be displayed on the mobile device <NUM>. It will be understood that the user manual or maintenance action info can be stored in any suitable location including on the mobile device <NUM>, on the component <NUM>, or at the computer <NUM>. If stored on the mobile device <NUM> or the computer <NUM>, the status information determined at <NUM> from the component <NUM> results in the relevant part of the manual being loaded onto the display <NUM>. If stored on the component <NUM>, the relevant part of the manual can be transmitted in its entirety to the mobile device <NUM> through the visual light communication data link, which can be beneficial because the manual is stored directly inside the component and versions and variants in the manual should be up-to-date thereon.

Further still, it is contemplated that upon completion of the action by maintenance personnel that the method <NUM> can either stop or continue. For example, the output from the light assembly <NUM> can change and again emit a light such as at <NUM>. The sensor <NUM> on the mobile device <NUM> determined the light emitted, as at <NUM> and the method can repeat.

Alternatively, the electrical power system <NUM> can run a self-test, at <NUM>, and the light assembly <NUM> can emit a second light, at <NUM>, related to a status of the component, after the maintenance and self-test, that is indicative of a failure or a passing of the self-test undertaken at <NUM>. The sensor <NUM> on the mobile device <NUM> can determine the light at <NUM> and at <NUM>, the failure or the passing of the self-test can be determined based on the light emitted at <NUM>. The mobile device <NUM> can then display on the display <NUM> an indication of whether the maintenance action was successful.

It will be understood that the method <NUM> of maintenance is flexible and the method <NUM> illustrated is merely for illustrative purposes. For example, the sequence of steps depicted is for illustrative purposes only, and is not meant to limit the method <NUM> in any way, as it is understood that the steps may proceed in a different logical order or additional or intervening steps may be included without detracting from embodiments of the invention. By way of non-limiting example, the method may also include automatically coupling to a remote processing center and the mobile device or an application thereon may automatically provide information thereto. Further, the method may also include automatically coupling to a manufacturer's database to provide information on the mobile device related to manufacturing information, repair information, or inventory information. In this manner, information may be made available to the OEM of the product, appropriate maintenance services can be conducted on time, and components may be adequately stocked. Further still, while the above has generally referenced visible light it will be understood that similar results using an Infra-Red (IR) communication medium instead of visual light can be utilized. The difference would be a lower data rate due to the reduced bandwidth and the inability to use displays and cameras as transducers.

The embodiments described above provide a variety of benefits including that they provide a means for personnel to interact with a system or component and a handheld device using light. The technical effect provided is that when personnel inspect the component, the light provided by the component or system to the mobile device may interact such that the personnel may receive information via visual light communication about the workings of the component or system and conveniently be supplied information relevant to the component and maintenance of such component. The above embodiments do not require high infrastructure and installation costs as many components already include a single status light that turns on and stays on for maintenance. Controller installation or reprogramming for modulations and do not require personnel to travel to maintenance access terminals in the cockpit to run tests on components and systems. Non-limiting examples that could benefit from such application within the exemplary aircraft can include electrical power system, landing gear system, fuel system, hydraulic system, flight data recording system, pneumatic system, water/waste system, flight surface control system, nitrogen generation system, smart valves, and smart actuators. The light assembly affords the opportunity for a very rapid fault diagnosis at minimal cost. To the extent not already described, the different features and structures of the various embodiments may be used in combination with each other as desired. The system also provides additional security over typical WiFi (RTM) transitions because visible light does not pass through walls, unlike WiFi (RTM). Thus, personnel must be physically located adj acent the component in order to establish communication. The benefits of a visual light communication data link approach include a higher data rate, the need for only one light source and the receiving system needs only a single photodiode instead of a camera lens.

That one feature may not be illustrated in all of the embodiments is not meant to be construed that it may not be, but is done for brevity of description.

Claim 1:
An avionics component maintenance system (<NUM>), comprising:
a light assembly (<NUM>) provided on an aircraft, the light assembly (<NUM>) configured to provide an output indicative of a status of an avionics component (<NUM>) on the aircraft; and
a mobile device (<NUM>) having a display (<NUM>) and an optical sensor (<NUM>) and configured to determine light emitted from the light assembly (<NUM>), and determine the status of the avionics component (<NUM>) to define a determined status (<NUM>) based on the determined light emitted (<NUM>), and provide on the display (<NUM>) an action for a user related to the avionics component (<NUM>) based on the determined status (<NUM>) ; and characterized in that:
a communication range between the light assembly (<NUM>) and the mobile device (<NUM>) can be adjusted by regulating at least one of brightness of the light assembly or divergence of the sensor, so as to require the mobile device (<NUM>) to be in sufficiently close proximity to the light assembly (<NUM>) to determine the light emitted from the light assembly (<NUM>).