Patent Publication Number: US-2021172351-A1

Title: Oil quality monitoring

Description:
BACKGROUND 
     Modern automotive vehicles often require substantial financial outlays and may represent a large part of a household or company budget. Regular maintenance is a key practice for extending the life of an automotive vehicle, as is prompt attention to indicators of vehicle malfunction or diminished vehicle performance. One essential maintenance practice is to regularly change motor oil, as its quality diminishes with use at high engine temperatures. Typically, the oil changing interval is a function of mileage (e.g., 3,000 miles) or time in service (e.g., three months) rather than a function of the oil quality itself. 
     U.S. Pat. No. 8,127,597 describes an oil condition sensing device that determines an oil viscosity level and an oil change event. An engine control module includes an oil diagnosis module and an oil reporting module, where the oil reporting module provides visual or auditory, indicators of oil status to the driver, and estimates the amount of time to the next oil change. The estimation may be adjusted based on the oil viscosity. The oil reporting module determines oil change events based on the data from the oil diagnosis module. 
     While improvements in localized data processing of such sensor data are currently sought and are addressed in the present disclosure, skilled artisans will agree that research and development efforts are also being directed to expanding the applicability of such sensor data. 
     SUMMARY 
     To monitor oil quality of an automotive vehicle, a sensor generates a signal indicative of a characteristic of the oil. A processor is configured to determine the oil quality from the signal. A communication component transmits an indication of whether the determined oil quality meets an unacceptability criterion to an external device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is diagram of an example environment in which the present inventive concept can be embodied. 
         FIG. 2  is a schematic block diagram of an example vehicle embodying the present inventive concept. 
         FIG. 3  is a schematic block diagram of an example system configuration by which the present inventive concept can be embodied. 
         FIG. 4  is a flow diagram illustrating an example oil quality monitoring process by which the present inventive concept may be embodied. 
     
    
    
     DETAILED DESCRIPTION 
     The present inventive concept is best described through certain embodiments thereof, which are described in detail herein with reference to the accompanying drawings, wherein like reference numerals refer to like features throughout. It is to be understood that the term invention, when used herein, is intended to connote the inventive concept underlying the embodiments described below and not merely the embodiments themselves. It is to be understood further that the general inventive concept is not limited to the illustrative embodiments described below and the following descriptions should be read in such light. 
     Additionally, the word exemplary is used herein to mean, “serving as an example, instance or illustration.” Any embodiment of construction, process, design, technique, etc., designated herein as exemplary is not necessarily to be construed as preferred or advantageous over other such embodiments. Particular quality or fitness of the examples indicated herein as exemplary is neither intended nor should be inferred. 
       FIG. 1  is diagram of an example environment in which the present invention can be embodied. As is illustrated, an automotive vehicle (or, simply vehicle  100 ) may be communicatively coupled to one or more server devices  110  (or, simply server  110 ) and/or one or more communication devices  120  through a communications network  105 . As can be appreciated, communications network  105  can be a public network, such as the Internet, or a private network such as a LAN or WAN network, or any combination thereof and can also include PSTN or ISDN sub-networks. Network  105  can also be wired, such as an Ethernet network, or can be wireless such as a cellular network including EDGE, 3G, 4G and 5G wireless cellular systems. The wireless network can also be WiFi, Bluetooth, or any other wireless form of communication that is known. 
     Server  110  is implemented on hardware and software resources of an entity to interoperate with vehicle  100  and communication device  120  over network  105 . The entity, such as a car dealership or an automobile manufacturer, may collect and analyze data from not only vehicle  100 , but from a large number of other selected vehicles as well. In addition to data collection and analysis functionality, server  110  may further implement an outwardly facing interface or portal through which external devices, such as communication device  120 , may access services and data provided by the entity. These and other features of server  110  are discussed below. 
     Communication device  120  is implemented on hardware and software resources of an entity to interoperate with vehicle  100  and server  110  over network  105 . Communication device  120  may be operated by a vehicle owner or operator to interact with vehicle systems, such as those described below. Communication device  120  may be implemented through various technologies, such as cellular phones, smartphones, tablet computers, laptop computers, desktop computers and the like. 
       FIG. 2  is a schematic block diagram of an example vehicle  100  embodying the present invention.  FIG. 2  presents a set of vehicle systems in block form, where individual blocks in the figure represent physical manifestations of vehicular systems that include mechanisms described in more detail below. The systems represented in  FIG. 2  are one set that can realize a fully functional automotive vehicle. Skilled artisans will recognize the physical manifestations of the systems associated with each block of  FIG. 2  without explicit details being set forth herein. 
     Although the embodiment of  FIG. 2  is illustrated and described as a road vehicle, upon review of this disclosure the skilled artisan will recognize how the principles of this disclosure can be applied in vehicles of other propulsion modes, e.g., aircraft, watercraft, hovercraft, etc. When vehicle  100  is embodied as a road vehicle, propulsion is achieved through a frictional engagement between wheels  203   a - 203   d , representatively referred to herein as wheel(s)  203 , and a road surface. Torque on wheels  203  may be provided by a power plant  210  that converts energy (internal combustion, electromotive) into rotational mechanical force. Wheels  203  are mechanically coupled to a vehicle body  205 , in which a vehicle occupant would ride and/or cargo would be carried. Mechanical coupling between wheels  203  and vehicle body  205  may be implemented any number of ways, such as by use of a conventional vehicle chassis (not illustrated) and/or a conventional vehicle suspension system (not illustrated). 
     Vehicle  200  may be self-contained to the extent that it can carry a vehicle occupant (and/or cargo) along a trajectory, typically hundreds of miles long, without having to replenish its energy source (combustible fuel refill, battery recharge or both). Power plant  210  derives power from an energy source, such as gasoline and/or a battery, and applies a rotational force to wheels  203  through a transmission/drive train  220 . These principles are well known and can be carried out by conventional means, except where otherwise indicated herein. 
     Distributed throughout vehicle  100  are numerous sensors  230 ; each generating a signal in response to a physical stimulus, e.g., pressure, temperature, position, voltage, current, velocity, torque, etc. Through such electrical signals, the state of vehicle  100  is obtained. As used herein, a vehicle state is defined by a selected (and often extensive) set of parameters associated with vehicular functionality. This includes base parameters such as the vehicle&#39;s speed, engine output, etc., but also includes parameters of other vehicle features, such as when the headlights are on and/or the turn signals activated. Vehicle state may include cabin temperature and entertainment system settings. Sensors  230  include the types and numbers of sensors necessary to determine the vehicle state at the granularity of information envisioned by a designer. To achieve various benefits of the invention, sensors  230  would include at least the techniques described in the example below. 
     Example data processing component  240  operates on, among other data, sensor data obtained from the aforementioned sensor signals to determine vehicle state information, which may be conveyed to a vehicle occupant through indicators or user interfaces implemented in vehicle  100 . For example, when vehicle  100  is in an unsatisfactory state (e.g., oil quality measurement meets unacceptability criterion), embodiments of the invention may indicate such through an iconic dashboard indicator or dashboard message displayed on display devices  270 , or any suitable way of providing the unsatisfactory state information to an end user, be that the driver or other occupant, a remote entity operating server  110  and/or operator of communication device  120 . Additionally, the unsatisfactory vehicle state may compel action by a vehicle control unit, such as to limit vehicle operation based on unsatisfactory state information. 
     Vehicle  100  may include mechanical systems  250  that implement various mechanical functions of a fully functional automotive vehicle. Mechanical systems  250  may include conventional controls such as steering, accelerating, and braking, as well as other mechanically-operated user controls. Mechanical systems  250  may include environmental and safety mechanisms. The present invention can be embodied in a vehicle, such as vehicle  100 , having any number of conventional mechanical systems in mechanical systems  250  that realize a fully functional automotive vehicle. 
     Vehicle  100  may include electrical systems  260  that implement various electrical/electronic functions. Electrical systems  260  comprise multiple electrical/electronic components, e.g., lamps, motors, solenoids, switches, electrical control circuits, entertainment systems, etc. typically interconnected by one or more wiring harnesses. Additionally, modern vehicles make use of processor circuits to implement monitor and control mechanisms. Thus, in certain embodiments, electrical systems  260  may include processing circuitry that implements control of vehicle  100 . Electrical systems  260  include those electrical/electronic components necessary to realize a fully functional automotive vehicle. Those having skill in the art will recognize many different electrical/electronic components and circuits that can be implemented in various embodiments without departing from the principles described in this disclosure. 
     Display devices  270  may implement user interfaces that convey varied information to a vehicle operator and, in certain embodiments, afford vehicle control, such as through a touchscreen. Display devices  270  may be distributed throughout vehicle  100 , such as on the dashboard or driver console and on the backs of cockpit seats for use by rear-seat occupants. Vehicle  100  may include display devices of different types, including individual lamps or indicators and high resolution LED display devices known in the art. The types and numbers of the display devices in display devices  270  will vary by vehicle design. 
     In certain implementations, vehicle  100  may include a vehicle network access device  280  by which vehicle  100  communicates with and is accessed by external devices, such as communication device  120  and server  110  illustrated in  FIG. 1 . Vehicle network access device  280  may include suitable communication circuitry to convey raw and processed information to external devices for purposes of maintenance, diagnostics, recordkeeping, and so on. A detailed example of such arrangement is provided below. 
       FIG. 3  is a schematic block diagram of an example system configuration by which the present invention can be embodied. The principle components of the system described in  FIG. 1 , i.e., vehicle  100 , communications device  120  and server  110 , are illustrated at a different level of abstraction in  FIG. 3 . In  FIG. 3 , vehicle  100  is communicatively coupled with a communication device  120  and a server device  110  through communications links  352  and  354 , respectively. Communications links  352  and  354  may be constructed in one or more media  355 , such as would be underlying communications network  105  illustrated in  FIG. 1 . To that end, each of vehicle  100 , communications device  120  and server  110  comprises communications components  340 ,  365  and  385 , respectively. Communications components  340 ,  365  and  385  comprise circuitry suitable for constructing links  352  and  354  according to corresponding communication procedures and protocols. Those having skill in the communications arts will recognize numerous techniques by which such communications may be achieved without departing from the principles described in this disclosure. 
     Additionally, each of vehicle  100 , communication device  120  and server  110  comprises computer resources at controller/data processor  330 , external data processor  370  and external data processor  390 , respectively. Each of these processor components comprise processor and memory resources: controller/data processor  330  comprises one or more processors  333  and memory  335 ; external data processor  370  comprises one or more processors  373  and memory  375 ; and external data processor  390  comprises one or more processors  393  and memory  395 . Each of the processors may be implemented on microprocessors, microcontrollers, digital signal processors, field programmable gate arrays, application specific integrated circuits, programmable logic devices, or using discrete logic circuits, as one of ordinary skill in the art would recognize. The memories may be implemented on random access memory circuits, read-only memory circuits, volatile memory circuits, persistent memory circuits, etc. including hard disk drives, optical drives, flash drives, memory integrated circuits and other forms known to skilled artisans. 
     As illustrated in  FIG. 3 , one or more sensors  314  may be mechanically engaged in an engine block  310  and communicatively coupled to a cavity  312  in which a quantity of engine oil  305  flows or is otherwise contained. Sensor  314  may be any device suitable for measurements that characterize oil quality. In one embodiment, sensor  314  is a commercially available viscosity sensor threaded into an appropriate port in engine block  310 . Other sensors may be used to determine oil quality, such as oil temperature sensors. 
     The electrical signal from sensor  314  may be conditioned (filtered, amplified, etc.) and, in certain embodiments, digitized (sampled) by signal conditioning and digitizing component  320  into computer data that can be operated on by computer resources of vehicle  100 . These data will be referred to herein as raw sensor data and may be used to calculate oil quality using appropriate conversion, typically achieved through calibration data provided by the sensor manufacturer. The conversion may be achieved through a formula implemented by processor instructions stored in memory  335  and executed by processor  333 . Alternatively, the conversion may be achieved through a suitable lookup table stored in memory  335 . 
     As illustrated in  FIG. 3 , computer resources of vehicle  100  may realize a data logging component  332 , by which oil quality data are timestamped and stored in data records in onboard memory  335 . In certain implementations, these logged data records are transmitted to one or more external entities, such as communication device  120  and/or server  110 . A vehicle identifier may be stored in memory  335  that can be transmitted with the logged data records so as to uniquely identify the dataset at the receiving entity. However, other implementations may omit transmitting all of the logged data records and may instead transmit indications of unfavorable conditions such as diminished oil quality. 
     Computer resources of vehicle  100  may implement a vehicle control component  334  by which vehicle systems are centrally controlled. Such control includes systems monitoring with responsive engine control, environmental (emissions) control, suspension control, cabin climate control and other automotive control functions known to skilled artisans. Additionally, vehicle control component  334  may be responsive to oil quality. For example, vehicle control component  334  may compel an indication that the oil quality meets a predetermined unacceptability criterion when such is the case. In certain embodiments, vehicle control component  334  may prevent engine operation if it is found that the oil quality meets the oil quality unacceptability criterion. It is to be understood that distributed control can also be implemented in embodiments, whereby different vehicle systems have a separate control component. 
     Computer resources of vehicle  100  may further implement a local analysis component  336 . Local analysis component  336  may analyze data derived from various sensors of vehicle  100  to determine the state of vehicle  100 . The state of vehicle  100  may be provided to vehicle control component  334  and a corresponding action or response may be compelled thereby. For example, the state of the vehicle may include an oil quality measurement and/or an indication that the oil quality meets an unacceptability criterion. The determination of whether the oil quality meets an unacceptability criterion may be a function realized by processor instructions stored in memory  335  and executed by processor  333 . As one example, an oil quality measurement, e.g., oil viscosity, may be compared to a threshold value at which the oil is considered unacceptable (or approaching unacceptable) as a lubricant. Such threshold value may be established by the power plant designer and/or may be determined through chemical and mechanical analysis at the oil provider. Regardless of its origin, the threshold value may be stored in memory  335  and used in a comparison routine executed by processor  333 . 
     Vehicle network access device  280  may be implemented on computer resources of controller/data processor component  330  and communication resources of communications component  340 . When so configured, embodiments of the present invention can participate in a cloud computing environment and other coordinated communications via communication links  352  and  354 . In one embodiment, the state of vehicle  100  includes an indication that the oil quality meets an unacceptability criterion. When such is the case, the state of the vehicle may be conveyed to communications device  120  and server  110 . 
     Application  372  may be realized on computer and communication resources of communication device  110  and may allow monitoring and control of vehicle  100  via communications link  352 . In certain implementations, various features of vehicle  100  are remotely controllable through application  372 . Such control can remotely operate features such as remote start, lighting, etc., and may receive vehicle state information. Application  372  may send messages to and receive messages from vehicle control component  334  through vehicle network access device  337  through, for example, a user interface portion of application  372 . Application  372  may comprise processor instructions stored in memory  375  and executed by processor  373  to communicate using communications component  365  with vehicle  100  and/or server  110 . 
     Server  110  may include persistent storage on which a database  394  is constructed. In one embodiment, application  372  may access database  394  in a limited way through records manager  392 , such as to maintain or otherwise view records on one&#39;s own vehicle. For example, application  372  may allow a user to enter oil maintenance information, such as date of oil change, type of oil, type of filter, etc., into the online records of the user&#39;s vehicle. Such information may alternatively be provided by an oil maintenance technician having a suitably configured application  372  at his/her disposal. These data may be maintained in the vehicle state information stored in memory  335  and may be used as input parameters of a mathematical model that predicts, among other things, the time the next oil change should be performed. 
     Database  394  may be constructed or otherwise configured to store massive amounts of data and may comply with various big data paradigms (e.g., data warehousing) known in the art. From the records of numerous vehicles of interest to an entity (manufacturer, automotive dealer, fleet manager, etc.), the aforementioned mathematical model may be constructed to provide a predicted output state for a given input state based on training on selected events recorded in database  394 . Database  394  may thus contain training data as well as test data. 
     Computer resources of server  110  may further implement a global analysis component  396  that analyzes data in database  394  to discover new information from vehicle state information of many vehicles. In one implementation, global analysis component  396  may assess whether overall life expectancy of a particular motor oil in a particular engine, as measured over many similarly equipped vehicles&#39; oil quality measurements, meets design specifications. Additionally, global analysis component  396  may implement more complex tasks, such as machine learning and predictive modeling to, for example, recommend oil maintenance procedures for particular vehicles given a particular oil quality measurement and other input parameters. To that end, global analysis component  396  may construct a mathematical model of power plant  210  that is trained on selected case data of database  394 . Once trained, such a model may, for example, generate a vehicle state with a certain output parameter (e.g., time to next oil change) for a given vehicle state with certain input parameter(s) (e.g., current oil viscosity, oil temperature, time since last oil change). 
     Once a model has been constructed by global analysis component  396 , it may be conveyed to local analysis component  336  via communication link  354 , where the model may be applied to local oil quality events (e.g., oil quality meets or is approaching an unacceptability criterion). The output of the model may be a predicted state that includes a predicted time to next oil change based on a current state that includes local oil quality measurements. An indication of this predicted state may be provided to the relevant entities, e.g., vehicle occupant in vehicle  100 , user of communication device  120  and entity in control of server  110 . 
     In one example embodiment of the invention, power plant  210  is an internal combustion engine. Sensor  314  may be a viscosity sensor situated to maintain continuous contact with oil  305  in engine block  310 . The electrical signal generated by sensor  314  may be sampled, such as by signal conditioning and digitizing component  320 , into raw sensor data. These raw sensor data may be provided to local analysis component  336 , whereby the raw sensor data are converted to viscosity values. In certain embodiments, the viscosity values may be logged by data logging component  332  and stored in data records of memory  335 . Local analysis component  336  may receive a time-series of viscosity values (along with other values making up the state of vehicle  100 ) and determines whether an unacceptable viscosity event occurs. As used herein, an unacceptable viscosity event occurs when oil is no longer suitable as a lubricant. In response to an unacceptable viscosity event, e.g., the measured oil viscosity being greater than a predetermined unacceptable viscosity value, vehicle  100  may transition into an unacceptable viscosity state. In this state, vehicle control component  334  may compel lighting an indicator and/or displaying a message on display devices  270 . Vehicle control component  334  may further transmit an indication of the occurrence of the unacceptable viscosity event to communication device  120  and/or to server  110 . 
     In addition to vehicle-localized processing, vehicle network access device  280  may transmit the viscosity time series and/or the indication that the viscosity of engine oil  305  meets the unacceptability criterion to server  110 . The data may be transmitted in association with a unique identifier, such as the vehicle identification number (VIN). The indication that the viscosity meets the unacceptability criterion may be added to records stored in database  394  via records manager component  392 . As discussed above, maintenance records may be kept online in database  394 , which may be accessed by application  372  of communication device  120 . 
     Database  394  may contain the records of numerous vehicles, such as would be of interest to vehicle dealers and/or manufacturers. Analysis of such records may be performed by global analysis component  395 , which may predict a time for next oil change through a suitable mathematical model. For example, global analysis component may identify that, for a certain engine design, the oil quality over a number of vehicles incorporating that engine design may depart from design specifications. Further analysis by vehicle designers may identify the cause of such shortcoming and corrective measures may be taken, including a vehicle recall. Other analyses may be performed by global analysis component as well. 
     In certain embodiments, vehicle network access device  280  may transmit the indication that the oil viscosity meets the unacceptability criterion to communication device  120 . Such transmission may occur over the Internet and displayed on communication device  120  through application  372 . Alternatively or additionally, the transmission may occur via a text message via cellular technology, should vehicle  100  be so equipped. Other notification techniques, such as email, may be used in embodiments as well. 
       FIG. 4  is a flow diagram illustrating an example oil quality monitoring process  400  by which the present inventive concept may be embodied. In operation  405 , oil characteristic data may be generated by an oil quality sensor, such as an oil viscosity sensor or an oil temperature sensor. In operation  410 , oil quality may be determined from the characteristic data and, in operation  415 , it may be determined whether the determined oil quality meets an unacceptability criterion. If so, process  400  may transition to operation  420 , whereby the driver (or other vehicle occupant) may be alerted to the low oil quality situation. In operation  425 , a communication device user may be alerted as well. As illustrated in  FIG. 4 , operations  420  and  425  are omitted when the oil quality is acceptable. However, it is to be understood that oil quality, as a parameter, may be accessed through a communication device, such as through a portal application that allows access and display of various parameters of the vehicle. 
     In operation  430 , oil quality information may be sent to a server and, in operation  435 , the oil quality information may be stored in a database. In operation  440 , the oil quality information stored in the database may be analyzed and used in operation  445  to generate a suitable model by which a predicted vehicle state is generated from a current vehicle state. In operation  450 , the model is applied to local vehicle state data to determine the predicted state. In operation  455 , corrective action may be taken, if necessary, based on the predicted state. 
     As will be appreciated by one skilled in the art, aspects of the present disclosure may be embodied as a system, method or computer program product. Accordingly, aspects of the disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “component,” “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon. 
     Computer program code for carrying out operations for aspects of the disclosure may be written in any combination of one or more programming languages, e.g., an object oriented programming language such as Java, Smalltalk, C++ or the like, or a conventional procedural programming language, such as the “C” programming language or similar programming languages. 
     Aspects of the present disclosure are described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks. The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, method and computer program products according to various embodiments of the disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block 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 sometime be executed in the reverse order, depending on the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more features, integers, steps, operations, elements, components, and/or groups thereof. 
     The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiment was chosen and described in order to best explain the principles of the inventive concept and the practical application, and to enable others of ordinary skill in the art to understand the inventive concept for various embodiments with various modifications as are suited to the particular use contemplated. 
     The descriptions above are intended to illustrate possible implementations of the present inventive concept and are not restrictive. Many variations, modifications and alternatives will become apparent to the skilled artisan upon review of this disclosure. For example, components equivalent to those shown and described may be substituted therefore, elements and methods individually described may be combined, and elements described as discrete may be distributed across many components. The scope of the invention should therefore be determined not with reference to the description above, but with reference to the appended claims, along with their full range of equivalents.