Table Of Content

oy ry AU we THE GENERIC INFE! <’ ENTIAL GenSAA Overview Se4s edee r eeqoee staebe For nearly 25 years. spacecraft missions were operated in essentially the same hSe‘ty o 3:e*4 ek _e— e dmiasnpnleary:s fhilulmeda nw itoh pearlapthoarnsu mmeorniict orteexdt s"f watching for limit violations or other indi- cators that signaled problems. Only in recent years have graphical user interfaces and expert systems been accepted within the control center environment to ens n help reduce operator workloads. Unfortunately, the development of these systems is often time consuming and costly. At the NASA Goddard Space Flight 4S ouy" Rt)Si n Center (GSFC), a domain-specific expert system development tool called GenSAA makes development quick and easy. Through the use of a highly graphical TSa« eqa»e /j™d ? he user interface and point-and-click operation, GenSAA facilitates the rapid, “programming-free” construction of Da—Dk intelligent graphical monitoring systems to ie<s3e Syws eare serve as real-time. fault-isolation assis- tants for spacecraft analysts. Although specifically developed to support real-time satellite monitoring, GenSAA can support the development of intelligent graphical monitoring systems in a variety of space and commercial applications GenSAA has demonstrably improved operations efficiency and increased capability through automation of routine operations functions and introduction of effective visualization capability within a control center. It is also a pathfinder and enabler ~ Chief, Mission Operations and System Development Division NASA's Goddard Space Flight Center “In a time when operations budgets are being cut back, GenSAA/Genie offers solutions for meeting lower staffing profiles while maintaining quality of service to our customers” Systems: Engineer, AlliedSignal Technical Services Corporation yrhi he —aw ” x" An Expert System Development Tool oe, “)2 { i “ty. GenSAA is a UNIX-bassofetwdar e tthn t ivbael tool that enables spacecranaaflytst s ny - to rapidly build simple, yet highly graphical, expert systems that are capable of tAeUd™ a yt performing real-time spacecrmoanfittor - T7 n) ;w e ing, fault detection, and fault isolation funcGetnie iis oan nextesnsi.on of GenSAA that adds spaceccroammfantd- ing and spacecraft pass automatifounnc - tions to GenSAA. GenSAA/Geniweas created as an alterntao tmoirev ceom - plex, expensive, commercially-available expert system developmeenvnirton - mentA psri.mar y goal in the development of GenSAA was to create a tool such that it was easy for domain experts (€.g.. a spacecraft engineer) to transfer their knowledge directly into a GenSAA =o expert system e«+eoe ee G SFC wanted to take advantage of the Characteristics of an Expert System Designed with GenSAA/Genie potential of graphical expert systems but needed a way to improve productivity in Easily Created and Modified - The process for developing specific expert systems using developing and maintaining these sys- GenSAA is straightforward and it car: be perlormed by trained users, e.g . spacecraft ana- tems. GenSAA/Genie addresses these lysts No programming languages need to be learned. No compilation or link step is neces- objectives by insulating the expert sys- sary before executing GenSAA expe’t systems, thus changes can be made dynamically tem developer from the programming details by way of a “direct-manipulation Rule-based - GenSAA/Genie supports the use of rules to represent spacecraft and payload environment’ in developing intelligent fault detection, monitoring, and fault solation knowledge Rule-based representations are Graphical monitoring systems intuitive and can closely model humen thoughts used to describe many of the reasoning processes Graphical - The GenSAA operations! user interface is X-Windows-based. !t supports both textual and graphical presentations cf health and status information as well as expert system fault isolation conclusions Hype: link techniques are supported to simplify navigation between GenSAA windows Gene piovides a graphical pass script builder to automate spacecraft pass operations Transparently interfaced with the Data Source - GenSAA/Genie is being used to create expert systems that support analysts in spacecraft control centers that use the Transportable Pavioad Operations Control! Center (TPOCC) architecture. TPOCC is a UNIX-based control center system architecture that is being used for several spacecraft missions such as Solar Anomalous and Mesospheric Particle Explorer (SAMPEX). X-Ray Timing Explorer (XTE). interplanetary Physics Laboratory (WIND). Polar Plasma Laboratory (POLAR), and Solar Heliospheric Observatory (SOHO). GenSAA understands TPOCC data formats. providing transparent access to the data GenSAA can also be configured to transparently receive =* _ data from sources other than TPOCC toSee” o~a~. odt Reai Time - GenSAA/Gemne expert systems are driven by real-time data sources and infer- ences are made in near-real-twme spacecraft telemetry that indicate the current status of the spacecraft and its operation Increased productivity is just one of the advantages offered by GenSAA. GenSAA's powerful set of user interface development and management above night Geme autonomoutsaklesy a tools allows an organization to create a consistent look and feel for the user interfaces spacecraft pass of all its expert systems. reducing user training time. while heightening efficiency. In addition, GenSAA isolates the user interface code from the application code. so user interface changes can be made quickly and convemently ~ PAKS oO. #5. “ ate fet anec ea ~~ shee ad 2 of) eAx e eke : ca ~ i ~ VP Sols iPe.b aotEtet e ’ Ws i> ony ee4m p e “SSShSe d _ - a) et iy Ti Dee oa ‘ ; Ge-e s hs‘est <3 Me4r) <Se«e= ee Peg “y‘x7 * - ‘ ¥ ey I 6% °y aX spe + "Se -~ t ae : = 7 774 $e ats pte oS | ad — ~ ¥ 2 - Eh Shs eese se oe. " > eae of en 3p Se w“s. ‘ —a - , Pre thay soa «™ = « “5 —-, A m cS > a ee . a” * a ad , _ “> ee rSalS ae & ~- » S“Er ve rne et aa r< “~ ri ia haa a es -< Produics Jtusit tvhe iBetginynin g GenSAA's Architecture GenSAA is composed of an integrated set of utilcailletd tihee Gsen,SA A system) and the graphical user interface. (1) Alission data - Mission as. x ables represent real-time data status of F :a¢, the monitored data (e.g. spacecraft The GenSAA Workibs aen onff-clineh t oo! ground system data) and related ground The Rule Builder - is used to create for specifying: support systems. This data origir ates from the rule base for a GenSAA expert sys- the external data source telemetry data tem. The rule base is a sei of expert system rules in “condition-action” (or “if - * Telemetry data server, s.w— ;, eo " * Expert system rules then”) format that may infer new facts eeeeeeeteeeeee)e ee * User interface layout (2) User-defined data - User-defined based on current facts. A rule contains data variables represent expected operat- one or more conditions and one or ing modes and equipment contigurations more actions GenSAA uses the C The Runtime Framework is a runtime This data originates from the user input Language Integrated Production executive that: System (CLIPS) inference engine and ecsnaideiin et~e.n., rule syntax. The GenSAA Rule Builder \t .e * Provides specified connections (3) Inferred data - Inferred datd vari- he data ~s) ables represen! conclusions imferred by can automate the creation of the CLIPS * frovidessp r od connections rules in the rule base Ths data onginates rule syntax using graphical means. The ee oe infer: »ngine from the inference engine Rule Buiider includes the Rule Editor window, the Condition Builder window. * Prowdes real hme inferencing * £ cules det.ed applications (4) EGG data - Externally-generated and the Action Builder window coated with tre GenSAA Workbench GenSAA (EGQ) variables are data avail- * Displays spe ied user specific able from other GenSAA expert systems witerace that run concurrently. This data o*iginates from other expert systems The GenSAA Workbeopenractesh i n above The GenSAA Architecture below The GenSAA Data Manager and Data an off-line mode (i.e., without being con- Details Window nected to a data source) on a Unix system and is created with three integrated utilities. The three utilities are: the Data . ** Managteher R,ul e Builder, and the User nbta t Interface Builder. ' ~~ The Data Manager — is used to con- ib! Struct and edit the four types of variables that are received from external data so exchan» with other GenSAA ex; stems. «ssociated with Ge: :Grap! Objects. iS-“)-e* Ae .F x:s 5’e A .e.; L E eeaeeeeeee eee e Using GenSAA (ae a The GenSAA Rule Editor, Condition Builder, and Action Builder — _—_——— pees — — The User Interface Builder — is used e oar for creating graphical user interfaces for . GenSAA expert systems. Users can popu- late a user interface with primitive objects eid. eee ae ani, |w s (e.g., text and polygons) or with complex o A objects (e.g., dials, bars, and xy plots). The user interface of a GenSAA expert system consists of a workspace, graphic windows, and graphic objects. These graphic elements can be dynamically created, customized, and linked with data without programming by using mechanisms provided in the User Interface Builder. The GenSAA Runtime Framework - provides the basic operational environment for a GenSAA expert system. The compo- nents of the GenSAA Runtime Framework are reused in each GenSAA expert system. They control the operation of a GenSAA above night The Condition Builder expert system during execution. They read the data interface specification, rule base below night User Interface Builder and user interface specification files created by the GenSAA Workbench to determine a specific behavior. The GenSAA Runtime Framework is implemented as a pair of UNIX processes that communicate with one another via sockets A third process is typically an external data source (e.g.. control center data server). Their functions are User Interface Process — manages the operation of the expert system's user interface It handles the user input, manages the display of windows (that may contain both text and graphics), and updates the visual attributes of the graphical objects. The User Interface Process also handles data requests and distribution The user interface windows. data-driven objects. and interaction objects are created in the GenSAA User interface Builder Inference Engine Process — manages the firing of rules in the rule base A rule is fired when all of its conditions are satistied: the conditions will often involve the current 4 values of mission. user-defined. EGG. and inferred data variables : Pr ie| External Data Server — sends data to the expert systern as requested 3a . The user interface of a GenSAA expert system typically includes color schematics and animated data-driven objects (such as rotating meters. sliding bar graphs, and toggle switches) that graphically display the dynamic aevrrt en values of telemetry data, user-defined data. and inferred conditions. 1!) ser interfaces a!- — typical!) —ontain hyperlinks that ‘ke it easier for the sp.-craft analyst to quickly display other graphics windows. >7 wk, t mirti& t eEcttWoiaSnlg ase Satb e a is a tool that allows easy construction of pass eAn =. = ar—e——n tion applications. A pass is a shori period of time mh ., 10 minutes at 90-minute intervals) during which the —— = Ta control center is in contact with the spacecraft. sending =r. ns. | commands and receiving data. A graphical workbench —— ag allows the user to build pass-script templates that encode the tasks necessary to mimic the sequence of activities that spacecraft controllers typically perform during a pass. These templates are then configured by a mission planner with data specific to a particular pass. The script is loaded into SA OM the Genie runtime system during pre-pass preparations y: 1e3)‘ ey ye and executed. A graphical status and control display tracks progress during the pass. Genie runs in the following three modes: .w 7w) w m‘v??h ° shadow Mode - tells what it would have done and @.> Commanding the Spacecraft with what kind of commands it would have sent in any Pe the Generic Inferential a of situation. ‘ Executor (Genie) oBhbodl aei a’ sel s+ 2 ¢ Advisory Mode - makes recommendations as to zo what to do and asks the operator whether or not fed Most spacecraft-ground contacts. or tc perform the command. a passes, are routine activities, during ..3 which the Flight Operations Team (FOT) ¢ Full Automation Mode - commands the spacecraft 03 oversees the downloading of tables and tells the operator what command it has performed a ind science data. as well as the loading 4 Ponbo. | !orec ands. The - ‘cess att ur ‘od and repetitive, Genie has been used successfully with the SAMPEX i other vy. ords, ar | automation can- spacecraft in all three of the above modes } idate. A FOT can» automation to : allow them to do more with constant or : decreasing resources. One ideal applica- Development of Genie required;three efforts: 1) minor modifications were made to ; tion is multi-spacecraft control centers, GenSAA software, adding interfaces to receive events from and send commands to. i where operation of mature spacecraft the control center software; 2) a graphical pass script builder was implemented: and 4 can be largely automated, allowing atten- 3) a script executor was “coded” in rules for the C Lanquage Integrated Production i tion to be focused on newly launched System (CLIPS), the inference engine at the heart of both GenSAA and Genie. 4 satellites. The FOT is immediately con- Applications for new missions are straightforward to build once routine spacecraft . 4 tacted if the automation system detects operation is established ‘= a non-nominal condition, making this approach low risk. ; » “ e~ ee — oo ea i. | on - above left and beiow right) Genie User Interface °--== as2 0 eTaee. eyS idfee e EwoOra"g ? Ort FT - we . . . -~ P|- -~s. Benefits of EA interfacing to External Sources GenSAA/Genie Productivity GenSAA assists the controllers with data monitoring resulting in more efficient and effective operations. Geme provides automated commanding Efficiency GenSAA enables rapid iterative development of expert systems within the application domain. Cost Savings GenSAA expert systems reduce development costs, improve operations efficiency, and keep expertise in-house as personnel turnover occurs. Genie reduces staff required for routine operations by completing automating spacecraft passes. Co-operating GenSAA Expert Flexibility User interlace changes can be made via GenSAA expert systems are intended to be the Workbench alone. with no changes to simple, modular expert systems with small rule bese the source code A typical GenSAA expert system might monitor and” isolate faults for one spacecraft subsystem. To Ease of Use The GenSAA WorkBench allows non-pro- grammers to create sophisticated user interfaces easily with the drag and drop technique subscribe” model ofc ommunication. an # level expert systems can simply monitor the conciu-~* Reusability sions made by the subsystem leve! expert systems. User interface designers can reuse % = To perform the publish-and-subsch: e method of infor- and share customized interaction objects “jm thon sharait hnirdg-fo,urt h component of the entire windows. and even sets of related “4 GenSAA Runtime Frametwhe oGenrSAkA ,Da ta windows, avoiding unnecessary duplication “Server, is used as a central repository in which of effort Expert system rules can also be GenSAA expert systems can “publish” information and shared from which other “subscribing” GenSAA expert systems ban receive the information when published. Additionally, Timely mal applications can “publish and subscribe” tc this Reduces development time and effort An altermenthaod tfior vshaeri ng data between allows quick and accurate response to nec- GenSAA expert systems and external data sources is essary modification via the CLIPS-socket interface. This interface allows for expert system rules to send data to an external Training Tool source and the external source can send data back Hands-on environment for training spacecraft controllers in a safe. off-line mode Potential Commercial Uses GenSAA could be used for any routinely monitored data source where anomaly detection, isolation, and correction are required including: +» Spacecraft. airplane, and automobile operations 44 Industrial process contro! | Power plant operations @ Security systems ¥ Biomedical monitoring of life support and diagnostic equipment ty e?b ari A ePe;TL T yE NT haar The NASA Software Advisory Council has chosen GenSAA for Honorable Mention in the 1996 NASA Software of the Year compe- tition. GenSAA was selected for its high degree of innoavnda eatse iofo usne, as well as its importot NAaSA'ns cmisesio n. At the GSFC, there is a strong interest cal expert systems to be created quickly and in a cost-emfanfnere. cGetnSiAA/vGeeni e is well suited for use on spacecraft projects that involve a series of similar, but non-iden- tical, missions such as NASA's Small Explorer (SMEX) and InternatioSnoalalr - TerrPhyesicss (ItSTPr) pirograamsl. I t is currently being applied to the SAMPEX, development suppofrort a reT RMM, FAST, SWAS, ACE, GRO, EUVE, and NOAA spacecraftT.h e EDOS and MIDEX missions are currently evaluating GenSAA/foGr uesen. GieneSA A provides ain evolutiaoppnroaacrh yt o monitoring functions to full pass automations. Although GenSAA is expected to increase automation and operator effectiveneists h,a s not been determined whether it will scale up to the larger problem of a fully automated control center. ‘Orelaehc ion| 2 \