02032nas a2200277 4500008004100000022001400041245005800055210005700113300001900170490000700189520121400196653002201410653003101432653002301463653003401486100002101520700001801541700001901559700002901578700002701607700002301634700001601657700002301673700001901696856003901715 2017 eng d a1539-908700aTask Transition Scheduling for Data-Adaptable Systems0 aTask Transition Scheduling for DataAdaptable Systems a105:1–105:280 v163 a
Data-adaptable embedded systems operate on a variety of data streams, which requires a large degree of configurability and adaptability to support runtime changes in data stream inputs. Data-adaptable reconfigurable embedded systems, when decomposed into a series of tasks, enable a flexible runtime implementation in which a system can transition the execution of certain tasks between hardware and software while simultaneously continuing to process data during the transition. Efficient runtime scheduling of task transitions is needed to optimize system throughput and latency of the reconfiguration and transition periods. In this article, we provide an overview of a runtime framework enabling the efficient transition of tasks between software and hardware in response to changes in system inputs. We further present and analyze several runtime transition scheduling algorithms and highlight the latency and throughput tradeoffs for two data-adaptable systems. To evaluate the task transition selection algorithms, a case study was performed on an adaptable JPEG2000 implementation as well as three other synchronous dataflow systems characterized by transition latency and communication load.
10aData adaptability10ahardware/software codesign10amodel-based design10aruntime transition scheduling1 aSandoval, Nathan1 aMackin, Casey1 aWhitsitt, Sean1 aGopinath, Vijay, Shankar1 aMahadevan, Sachidanand1 aMilakovich, Andrew1 aMerry, Kyle1 aSprinkle, Jonathan1 aLysecky, Roman uhttp://doi.acm.org/10.1145/304749800591nas a2200133 4500008004100000245010300041210006900144260003300213653001300246653002400259653002600283100001900309856012900328 2014 eng d00aAutomatic Verification of Dynamic Constraints in LTI Control Systems Through Model Transformations0 aAutomatic Verification of Dynamic Constraints in LTI Control Sys aWashington, DCbNSFc03/201410aControls10aDynamic Constraints10aModel Transformations1 aWhitsitt, Sean uhttps://csl.arizona.edu/content/automatic-verification-dynamic-constraints-lti-control-systems-through-model-transformations01888nas a2200145 4500008004100000245010500041210006900146260000900215300001000224520140100234100001901635700002301654700001901677856004601696 2014 eng d00aGenerating Model Transformations for Mending Dynamic Constraint Violations in Cyber Physical Systems0 aGenerating Model Transformations for Mending Dynamic Constraint c2014 a35-403 aCyber physical systems by definition involve design constraints addressing the computation and communication necessary to control physical systems. These systems have been modeled using domain specific modeling languages, but some limitations exist in the continued application of such a modeling approach to more complex, or safety-critical, systems. Specifically, it is well known how to formulate constraints in a domain-specific modeling language in order to prevent users from building invalid structures, but existing constraint-based techniques do not take into consideration design requirements that may require analysis in the physical domain (i.e. dynamic constraints). Those analysis results, when interpreted by a domain expert, can inform changes to the model: unfortunately, this process does not scale. This paper presents an approach to integrating dynamic constraints that cannot be enforced using structural model constraints. The technique uses expert blocks to analyze systems and generates model transformations specific to the system using the results of those analyses to fix constraint violations. The paper describes a Dynamic Constraint Feedback (DCF) methodology for integrating this technique into existing systems from a generic perspective. Specific examples in this paper are derived from the domain of data adaptable reconfigurable embedded systems (DARES).
1 aWhitsitt, Sean1 aSprinkle, Jonathan1 aLysecky, Roman uhttp://dx.doi.org/10.1145/2688447.268845401760nas a2200133 4500008004100000245008300041210006900124260003600193300001400229520129400243100001901537700002301556856004701579 2014 eng d00aA Hybrid Controller for Autonomous Vehicle Lane Changing with Epsilon Dragging0 aHybrid Controller for Autonomous Vehicle Lane Changing with Epsi aPortland, OregonbIEEEc06/2014 a5307-53123 aTrajectory control for a ground vehicle typically utilizes the error from the desired path or trajectory (i.e., crosstrack error) to produce velocity and steering commands. If an obstacle is in the path, previous techniques have synthesized a new trajectory that avoids the obstacles, and the vehicle directly follows this new path. This approach has drawbacks at high velocity, because the synthesized trajectory must satisfy the stability criteria of the vehicle. This paper introduces a technique which we call epsilon dragging The approach modifies the existing trajectory by some value ε in order to avoid an obstacle at high speeds, while preserving the original trajectory as the desired path. Epsilon dragging is performed by inducing an additional error to the crosstrack error of the vehicle; this induced error can be bounded in order to stay within the velocity/turnrate profile that governs safe behavior at high speeds. The paper provides a method to construct epsilon such that a vehicle can avoid an obstacle at high speeds without the need to verify the trajectory’s curvature before it is synthesized. The technique is demonstrated in completing a lane-change maneuver at different velocities, and verifying that the velocity/turnrate profiles are not exceeded.
1 aWhitsitt, Sean1 aSprinkle, Jonathan uhttp://dx.doi.org/10.1109/ACC.2014.685945000542nas a2200109 4500008004100000245012200041210006900163260004700232490000800279100001900287856012600306 2014 eng d00aA Methodology for Mending Dynamic Constraint Violations in Cyber Physical Systems By Generating Model Transformations0 aMethodology for Mending Dynamic Constraint Violations in Cyber P aTucson, AZbUniversity of Arizonac12/20140 vPhD1 aWhitsitt, Sean uhttps://csl.arizona.edu/content/methodology-mending-dynamic-constraint-violations-cyber-physical-systems-generating-model00541nas a2200145 4500008004100000245009900041210006900140260003700209100001900246700002100265700001900286700001800305700002300323856004900346 2013 eng d00aEfficient Reconfiguration Methods to Enable Rapid Deployment of Runtime Reconfigurable Systems0 aEfficient Reconfiguration Methods to Enable Rapid Deployment of aPacific Grove, CAbIEEEc11/20131 aLysecky, Roman1 aSandoval, Nathan1 aWhitsitt, Sean1 aMackin, Casey1 aSprinkle, Jonathan uhttp://dx.doi.org/10.1109/ACSSC.2013.681040101875nas a2200205 4500008004100000245006800041210006500109260002600174300001000200520125300210653002401463653002001487100002001507700001701527700001601544700002101560700001901581700002301600856004601623 2013 eng d00aGenerating a {ROS/JAUS} Bridge for an Autonomous Ground Vehicle0 aGenerating a ROSJAUS Bridge for an Autonomous Ground Vehicle aIndianapolis, INbACM a13-183 aRobotic systems have truly benefitted from standardized middleware that can componentize the development of new capabilities for a robot. The popularity of these robotic middleware systems has resulted in sizable libraries of components that are now available to roboticists. However, many robotic systems (such as autonomous vehicles) must adhere to externally defined standards that are not blessed with such a large repository of components. Due to the real-time and safety concerns that accompany the domain of unmanned systems, it is not trivial to interface these middleware systems, and previous attempts to do so have succeeded at the cost of ad hoc design and implementation. This paper describes a domain-specific approach to the synthesis of a bridge between the popular Robotic Operating System (ROS) and the Joint Architecture for Unmanned Systems (JAUS). The domain-specific nature of the approach permits the bridge to be limited in scope by the application’s specific messages (and their attribute mappings between JAUS/ROS), resulting in smaller code size and overhead than would be incurred by a generic solution. Our approach is validated by tests performed on an unmanned vehicle with and without the JAUS/ROS bridge.
10aautonomous vehicles10aCode Generation1 aMorley, Patrick1 aWarren, Alex1 aRabb, Ethan1 aBunting, Matthew1 aWhitsitt, Sean1 aSprinkle, Jonathan uhttp://dx.doi.org/10.1145/2541928.254193100397nas a2200121 4500008004100000245006000041210006000101300001000161100001900171700002300190700001900213856004300232 2013 eng d00aModel Based Development with the Skeleton Design Method0 aModel Based Development with the Skeleton Design Method a12-191 aWhitsitt, Sean1 aSprinkle, Jonathan1 aLysecky, Roman uhttp://dx.doi.org/10.1109/ECBS.2013.1600328nas a2200121 4500008004100000245003200041210003200073300001200105490000700117100001900124700002300143856004000166 2013 eng d00aModeling Autonomous Systems0 aModeling Autonomous Systems a396-4130 v101 aWhitsitt, Sean1 aSprinkle, Jonathan uhttp://dx.doi.org/10.2514/1.I01003900511nas a2200145 4500008004100000245009600041210006900137300001200206100002100218700001800239700001900257700001900276700002300295856004700318 2013 eng d00aRuntime Hardware/Software Task Transition Scheduling for Runtime-Adaptable Embedded Systems0 aRuntime HardwareSoftware Task Transition Scheduling for RuntimeA a342-3451 aSandoval, Nathan1 aMackin, Casey1 aWhitsitt, Sean1 aLysecky, Roman1 aSprinkle, Jonathan uhttp://dx.doi.org/10.1109/FPT.2013.671838201894nas a2200529 4500008004100000245015900041210006900200260001000269300001000279653002800289653002200317653003800339653003600377653002400413653001800437653001600455653002900471653002900500653004500529653002100574653003500595653001600630653001100646653001300657653002600670653003100696653004400727653003100771653004700802653002600849653003300875653001500908653002300923653003400946653002400980653001201004653003701016653002001053653003301073653003501106100002101141700001801162700001901180700001901199700002301218856012301241 2013 eng d00aSystem Throughput Optimization and Runtime Communication Middleware Supporting Dynamic Software-Hardware Task Migration in Data Adaptable Embedded Systems0 aSystem Throughput Optimization and Runtime Communication Middlew cApril a59-6810acombinatorial explosion10aData adaptability10adata adaptable design methodology10adata adaptable embedded systems10adata configurations10adata handling10aData models10adata profile correlation10adesign time optimization10adynamic software-hardware task migration10aembedded systems10aField programmable gate arrays10aFIFO queues10aFiring10aHardware10ahardware accelerators10ahardware-software codesign10ahardware-software communication wrapper10ahardware/software codesign10ahardware/software communication middleware10aheuristic programming10aheuristic search methodology10amiddleware10amodel-based design10aPareto optimal configurations10aPareto optimisation10aRuntime10aruntime communication middleware10asearch problems10asimulation-based methodology10asystem throughput optimization1 aSandoval, Nathan1 aMackin, Casey1 aWhitsitt, Sean1 aLysecky, Roman1 aSprinkle, Jonathan uhttps://csl.arizona.edu/content/system-throughput-optimization-and-runtime-communication-middleware-supporting-dynamic01891nas a2200181 4500008004100000245009500041210006900136300001200205520129700217100001901514700002101533700001701554700002301571700003201594700001901626700002101645856004301666 2012 eng d00aOn the Extraction and Analysis of a Social Network with Partial Organizational Observation0 aExtraction and Analysis of a Social Network with Partial Organiz a249-2563 aThe behavior of an organization may be inferred based on the behavior of its members, their contacts, and their connectivity. One approach to organizational analysis is the construction and interpretation of a social network graph, where entities of an organization (persons, vehicles, locations, events, etc.) are nodes, and edges represent varying kinds of connectivity between entities. This paper describes a transformation based approach to the extraction of a social network graph, where the original data comprising (partial) observation of the organization are embedded on a graph with a different ontology, and with many entities and edges that are unrelated to the organization of interest. Social network extraction allows the inference of implied relationships, and the selection of relationships relevant for intended analysis techniques. The analysis of the resulting social network graph is based on organizational and individual analysis, in order to permit an advanced user to draw conclusions regarding the behavior of the organization, based on established social network graph metrics. The results of the paper include a discussion of the complexity of analysis, and how the observation data graph is pruned in order to scale the application of analysis algorithms.
1 aWhitsitt, Sean1 aGopalan, Abishek1 aCho, Sangman1 aSprinkle, Jonathan1 aRamasubramanian, Srinivasan1 aSuantak, Liana1 aRozenblit, Jerzy uhttp://dx.doi.org/10.1109/ECBS.2012.3300381nas a2200097 4500008004100000245005800041210005800099260002200157100001900179856008500198 2012 eng d00aModeling and Code Generation with Autonomous Vehicles0 aModeling and Code Generation with Autonomous Vehicles aInnsbruck Austria1 aWhitsitt, Sean uhttps://csl.arizona.edu/content/modeling-and-code-generation-autonomous-vehicles00443nas a2200133 4500008004100000245007200041210006900113260001200182300000800194100001900202700002300221700001900244856004600263 2012 eng d00aAn Overseer Control Methodology for Data Adaptable Embedded Systems0 aOverseer Control Methodology for Data Adaptable Embedded Systems c08/2012 a1-61 aWhitsitt, Sean1 aSprinkle, Jonathan1 aLysecky, Roman uhttp://dx.doi.org/10.1145/2508443.250844800388nas a2200109 4500008004100000245006800041210006600109300001400175100001900189700002300208856004700231 2012 eng d00aA Passenger Comfort Controller for an Autonomous Ground Vehicle0 aPassenger Comfort Controller for an Autonomous Ground Vehicle a3380-33851 aWhitsitt, Sean1 aSprinkle, Jonathan uhttp://dx.doi.org/10.1109/CDC.2012.642604901728nas a2200253 4500008004100000020002200041245007300063210006900136260002700205300001400232520095300246653002201199653002901221653001101250653002901261100001901290700002101309700002001330700002201350700001601372700001701388700002301405856004601428 2011 eng d a978-1-4503-1183-000aConstrained data acquisition for mobile citizen science applications0 aConstrained data acquisition for mobile citizen science applicat aNew York, NY, USAbACM a267–2723 aThe popularity and ubiquity of personal mobile computing devices–-coupled with their powerful sensing capabilities–-allow their application in the structured collection of data for societal benefit and science applications. Citizen scientists are willing users and active contributors to scientific research and applications, but if they gather data in an unconstrained or ad hoc manner, their efforts may be of little scientific value. In this paper, we present a user interface for a mobile device which is properly constrained to permit the gathering of valid scientific data. This helps to achieve the goal that any individual with a basic familiarity of the device (but not of the science) should be able to obtain useful data with little learning required. As a use case for this concept, we present a mobile application that allows users to collect location-stamped images to supplement satellite data for climate change research.
10acitizen scientist10adomain-specific modeling10aiphone10amobile phone programming1 aWhitsitt, Sean1 aBarreto, Armando1 aHudson, Maribel1 aAl-Helal, Hussain1 aChu, Diyang1 aDidan, Kamel1 aSprinkle, Jonathan uhttp://dx.doi.org/10.1145/2095050.209509501544nas a2200133 4500008004100000245007600041210006900117260001000186300001400196520111500210100001901325700002301344856004301367 2011 eng d00aMessage Modeling for the Joint Architecture for Unmanned Systems (JAUS)0 aMessage Modeling for the Joint Architecture for Unmanned Systems cApril a251–2593 aThe Joint Architecture for Unmanned Systems (JAUS) is a standard for sensing, control, and computational communication of components for unmanned systems. This paper presents a modeling environment capable of producing a domain-specific prototype of the software necessary for inter-computer communications. A metamodel is used to provide the domain-specific modeling language to model both the messages used in JAUS, and the shell interfaces for components that transmit and receive those messages. The produced artifacts are C and C++ code that can be used in unmanned systems and simulations of such systems, including tests that validate the structure and behavior of the generated code. The generated code is compatible with standard JAUS implementations, and is validated using the OpenJAUS open source API and framework. Future work describes the second spiral of features and behaviors (currently in the design phase). The case study and test environment for the software generated by this project is an autonomous ground vehicle, modeled on a Ford Escape Hybrid that is used in laboratory experiments.1 aWhitsitt, Sean1 aSprinkle, Jonathan uhttp://dx.doi.org/10.1109/ECBS.2011.1700416nas a2200097 4500008004100000245007400041210006900115260003400184100001900218856008100237 2011 eng d00aModeling the Messaging and Component Interfaces of Autonomous Systems0 aModeling the Messaging and Component Interfaces of Autonomous Sy bUniversity of ArizonacAugust1 aWhitsitt, Sean uhttp://bracton.ece.arizona.edu/svn/jmsgroup/trunk/public/whitsitt-thesis.pdf02506nas a2200193 4500008004100000245007400041210006900115260001200184520185900196100001902055700002102074700001902095700002202114700002002136700001602156700002302172700001702195856010002212 2010 eng d00aCitizen Science in Support of Vegetation Index and Phenology Research0 aCitizen Science in Support of Vegetation Index and Phenology Res cOctober3 aVegetation indices (VIs) are simple transformations of images into proxy measures of greenness and vegetation health and change over time. They are also used to derive information about the land surface phenology status, providing extensive spatial coverage and direct support for global ecosystem models. These measurements however contain large uncertainties and errors. A new suite of mobile devices, equipped with geo-location, image capture, and transmission capabilities could aid with vegetation phenology observations and documentation. The iPhone, with its wide distribution and array of sensors, can contribute significantly to the field of citizen science. In this project we are developing an end-to-end system for the collection, processing, and visualization of land surface vegetation phenology. The system consists of a client-server application and a Google Earth based visualization model. The client side (an iPhone app) intuitively guides the observer to capture up to three images per location: a close-up image of leaves, flowers, or fruits, an individual plant image, and a panoramic landscape image. The iPhone automatically embeds location, orientation, date/time, and other metadata with the images and allows the observer to add text comments. The images are then transmitted to the server, where they are validated, post-processed, archived, and made available to the interactive visualization system. The images are separated into primary colors and processed into a greenness index comparable to the classical VI. These measurements are then plotted against satellite based VI time series to aid in their validation and the characterization of the location phenology. With this effort we hope to recruit global observers into contributing to the field of land surface vegetation change detection and characterization.
1 aWhitsitt, Sean1 aBarreto, Armando1 aRam, Sundaresh1 aAl-Helal, Hussain1 aHudson, Maribel1 aChu, Diyang1 aSprinkle, Jonathan1 aDidan, Kamel uhttps://csl.arizona.edu/content/citizen-science-support-vegetation-index-and-phenology-research