By Topic

Cyber-Physical Systems (ICCPS), 2012 IEEE/ACM Third International Conference on

Date 17-19 April 2012

Filter Results

Displaying Results 1 - 25 of 62
  • [Front cover]

    Publication Year: 2012 , Page(s): C1
    Save to Project icon | Request Permissions | PDF file iconPDF (1997 KB)  
    Freely Available from IEEE
  • Proceedings. 2012 IEEE/ACM Third International Conference on Cyber-Physical Systems. ICCPS 2012

    Publication Year: 2012 , Page(s): i
    Save to Project icon | Request Permissions | PDF file iconPDF (63 KB)  
    Freely Available from IEEE
  • Proceedings. 2012 IEEE/ACM Third International Conference on Cyber-Physical Systems ICCPS 2012. 17-19 April 2012, Beijing, China

    Publication Year: 2012 , Page(s): iii
    Save to Project icon | Request Permissions | PDF file iconPDF (110 KB)  
    Freely Available from IEEE
  • [Copyright Notice]

    Publication Year: 2012 , Page(s): iv
    Save to Project icon | Request Permissions | PDF file iconPDF (109 KB)  
    Freely Available from IEEE
  • 2012 IEEE/ACM Third International Conference on Cyber-Physical Systems ICCPS 2012 - Table of contents

    Publication Year: 2012 , Page(s): v - ix
    Save to Project icon | Request Permissions | PDF file iconPDF (145 KB)  
    Freely Available from IEEE
  • Message from General Co-chairs and Program Chair

    Publication Year: 2012 , Page(s): x
    Save to Project icon | Request Permissions | PDF file iconPDF (81 KB) |  | HTML iconHTML  
    Freely Available from IEEE
  • Organizing Committee

    Publication Year: 2012 , Page(s): xi
    Save to Project icon | Request Permissions | PDF file iconPDF (104 KB)  
    Freely Available from IEEE
  • Technical Program Committee

    Publication Year: 2012 , Page(s): xii
    Save to Project icon | Request Permissions | PDF file iconPDF (103 KB)  
    Freely Available from IEEE
  • Reviewers

    Publication Year: 2012 , Page(s): xiii
    Save to Project icon | Request Permissions | PDF file iconPDF (60 KB)  
    Freely Available from IEEE
  • Rationale and Architecture Principles for Medical Application Platforms

    Publication Year: 2012 , Page(s): 3 - 12
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (578 KB) |  | HTML iconHTML  

    The concept of "system of systems" architecture is increasingly prevalent in many critical domains. Such systems allow information to be pulled from a variety of sources, analyzed to discover correlations and trends, stored to enable real-time and post-hoc assessment, mined to better inform decision-making, and leveraged to automate control of system units. In contrast, medical devices typically have been developed as monolithic stand-alone units. However, a vision is emerging of a notion of a medical application platform (MAP) that would provide device and health information systems (HIS) interoperability, safety critical network middleware, and an execution environment for clinical applications ("apps") that offer numerous advantages for safety and effectiveness in health care delivery. In this paper, we present the clinical safety/effectiveness and economic motivations for MAPs, and describe key characteristics of MAPs that are guiding the search for appropriate technology, regulatory, and ecosystem solutions. We give an overview of the Integrated Clinical Environment (ICE) - one particular achitecture for MAPs, and the Medical Device Coordination Framework - a prototype implementation of the ICE architecture. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • From Offline toward Real-Time: A Hybrid Systems Model Checking and CPS Co-design Approach for Medical Device Plug-and-Play (MDPnP)

    Publication Year: 2012 , Page(s): 13 - 22
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1125 KB) |  | HTML iconHTML  

    Hybrid systems model checking is a great success in guaranteeing the safety of computerized control cyber-physical systems (CPS). However, when applying hybrid systems model checking to Medical Device Plug-and-Play(MDPnP) CPS, we encounter two challenges due to the complexity of human body: i) there are no good offline differential equation based models for many human body parameters, ii) the complexity of human body can result in many variables, complicating the system model. In an attempt to address the challenges, we propose to alter the traditional approach of offline hybrid systems model checking of time-unbounded (i.e., long-run) future behavior to online hybrid systems model checking of time-bounded (i.e., short-run) future behavior. According to this proposal, online model checking runs as a real-time task to prevent faults. To meet the real-time requirements, certain design patterns must be followed, which brings up the co-design issue. We propose two sets of system co-design patterns for hard real-time and soft real-time respectively. To evaluate our proposals, a case study on laser tracheotomy MDPnP is carried out. The study shows the necessity of online model checking. Furthermore, test results based on real-world human subject trace show the feasibility and effectiveness of our proposed co-design. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Implantable Pacemakers Control and Optimization via Fractional Calculus Approaches: A Cyber-Physical Systems Perspective

    Publication Year: 2012 , Page(s): 23 - 32
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (495 KB) |  | HTML iconHTML  

    Managing cardiac disease and abnormal heart rate variability remain challenging problems with an enormous economic and psychological impact worldwide. Consequently, the purpose of this paper is to introduce a fractal approach to pacemaker design based on the constrained finite horizon optimal control problem. This is achieved by modeling the heart rate dynamics via fractional differential equations. Also, by using calculus of variations, we show that the constrained finite horizon optimal control problem can be reduced to solving a linear system. Finally, we discuss the hardware complexity involved in the practical implementation of fractal controllers. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Investigating Communication Infrastructure of Next Generation Air Traffic Management

    Publication Year: 2012 , Page(s): 35 - 44
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (327 KB) |  | HTML iconHTML  

    Growing demand for use of the National Airspace System (NAS) has resulted in research and development programs to modernize the air traffic control system. The primary focus of the US FAA's Next Generation Air Transportation System (NextGen) plan is to transform the air transportation system into a more flexible, adaptive, and highly automated system capable of handling two to three times the current traffic. According to the NextGen plan, Automatic Dependent Surveillance - Broadcast (ADS-B) is designed to improve the safety, capacity, and efficiency of the NAS. ADS-B works by broadcasting flight information such as the flight number, position, speed and intent using satellite-based navigation systems, to other aircraft or air traffic control facilities. Our research interests focus on the interoperability of the ADS-B data link with existing surveillance systems and operational ability of ADS-B to assist the flight crew by meeting safety assurance. Because the NAS involves a multitude of inter-acting agents and technologies, the high complexity of integrated sensing and decision support for the air traffic control is the main challenge. We have developed a simulation environment which includes an air traffic model, existing surveillance systems, ADS-B systems, and wireless channel model. The critical issue of the interoperability and collaboration between existing systems and ADS-B is validated. Two parts of the interference issue are analysed: (1) interference from ADS-B to existing systems, and (2) interference from existing systems to the ADS-B. It is shown that ADS-B meets the performance requirements of both air-to-ground and air-to-air ranges. Furthermore, the effect of ground surveillance systems and aircraft density to the ADS-B performance along the flight path is analysed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Cyber-Physical Challenges for Space Systems

    Publication Year: 2012 , Page(s): 45 - 52
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (556 KB) |  | HTML iconHTML  

    Modern space systems necessarily have a tight coupling between onboard cyber (processing, communication) and physical (sensing, actuation) elements to survive the harsh extraterrestrial environment and successfully complete ambitious missions. This article first summarizes space exploration missions and existing platforms that to-date have been developed by ad hoc, one-of-a-kind cyber-physical integration efforts. The primary goal of this paper is to present a series of cyber-physical systems (CPS) challenges that, if addressed in the emerging science of CPS, will greatly facilitate complex space systems development in the future. Areas of focus include spacecraft communications, driven by relative orbiting network node positions as well as bandwidth and power considerations, attitude control and orbit determination, and space robotics and science payload systems. A strong CPS challenge problem is introduced: scheduling the instructions executed on a small spacecraft processor such that the magnetic field introduced by this processor induces torques favorable for spacecraft pointing. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Rhythmic Tasks: A New Task Model with Continually Varying Periods for Cyber-Physical Systems

    Publication Year: 2012 , Page(s): 55 - 64
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (436 KB) |  | HTML iconHTML  

    Traditional mechanical subsystems in automobiles are being replaced by electronically controlled systems, often with no mechanical backup. This trend towards "drive-by-wire" systems is becoming increasingly popular. In these cyber-physical systems, a critical task not meeting its timing deadline can lead to a safety violation and damage to life and/or property. Classical real-time scheduling techniques such as RMS and EDF can be used to guarantee the schedulability of periodic tasks. However, certain critical tasks like the engine control task are activated by engine events such as pulses generated by sensors at the engine crankshaft. The periods of these engine tasks vary continually and even dramatically depending on the engine speed. The conventional periodic task model is inadequate for handling such tasks in cyber-physical systems due to its pessimism when combined with common schedulability analyses. In this paper, we define a new task model called Rhythmic Tasks for tasks having periods that vary due to external physical events. To the best of our knowledge, this is the first model that considers continually varying periods for fixed-priority scheduling in dynamic operating environments. We formally define the rhythmic task model and study its scheduling properties. In the context of rhythmic engine control tasks, we offer schedulability tests for determining the maximum possible utilization under the steady state, which is related to the physical engine speed. We also investigate the range of possible engine acceleration and deceleration rates. We show that excessive acceleration and deceleration can make the system unschedulable. We provide algorithms to find the appropriate ranges for acceleration and deceleration rates. We use a specific case study of engine control to illustrate our analysis. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Pattern-Based Composition and Analysis of Virtually Synchronized Real-Time Distributed Systems

    Publication Year: 2012 , Page(s): 65 - 74
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (261 KB) |  | HTML iconHTML  

    Designing and verifying distributed protocols in a multi-rate asynchronous system is, in general, extremely difficult when the distributed computations require consistent input views, consistent actions and synchronized state transitions. In this paper, we address this problem and introduce a formal, complexity-reducing architectural pattern, called Multi-Rate PALS system, to support virtual synchronization in multi-rate distributed computations. The pattern supports a component to be virtually synchronized with other components in different instantiations of this pattern. We present an application of a hierarchical control system to show that the composition of these instantiations can be used to achieve desired system-level properties, such as distributed consistency and distributed coordination. We verify the logical synchronization guarantee of this pattern, which holds as long as the pattern assumptions are satisfied. We also discuss the correctness analysis necessary to validate these assumptions and provide a tool support to perform this analysis automatically on the AADL models. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fault Resilient Real-Time Design for NoC Architectures

    Publication Year: 2012 , Page(s): 75 - 84
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (405 KB) |  | HTML iconHTML  

    Performance and time to market requirements cause many real-time designers to consider components, off the shelf (COTS) for real-time cyber-physical systems. Massive multi-core embedded processors with network-on-chip (NoC) designs to facilitate core-to-core communication are becoming common in COTS. These architectures benefit real-time scheduling, but they also pose predictability challenges. In this work, we develop a framework for Fault Observant and Correcting Real-Time Embedded design (Forte) that utilizes massive multi-core NoC designs to reduce overhead by up to an order of magnitude and to lower jitter in systems via utilizing message passing instead of shared memory as the means for intra-processor communication. Message passing, which is shown to improve the overall scalability of the system, is utilized as the basis for replication and task rejuvenation. This improves fault resilience by orders of magnitude. To our knowledge, this work is the first to systematically map real-time tasks onto massive multi-core processors with support for fault tolerance that considers NoC effects on scalability on an real hardware platform and not just in simulation. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Platform for Evaluating Autonomous Intersection Management Policies

    Publication Year: 2012 , Page(s): 87 - 96
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (994 KB) |  | HTML iconHTML  

    There is a significant push towards greater vehicular autonomy on roads to increase convenience and improve overall driver experience. To enable this autonomy, it is imperative that cyber-physical infrastructure be deployed to enable efficient control and communication. An essential component of such road instrumentation is intersection management. This paper develops an intersection management platform that provides the sensing and communication infrastructure needed to enable efficient intersection management policies. The test bed, located in a indoor laboratory, consists of an intersection and multiple robotic vehicles that can sense and communicate. Whereas traditional approaches to intersection management rely on simulations, this test bed enables the first realistic evaluation of several intersection management policies. Six simple but practical centralized and distributed policies are evaluated and compared against the current state of the art, i.e., traffic signals and stop signs. Through extensive experimentation, this paper concludes that, in the scenario tested, even a simple coordinated management policy can halve vehicular delay, while improving the aggregate traversal time of the intersection by 169%. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On Resource Overbooking in an Unmanned Aerial Vehicle

    Publication Year: 2012 , Page(s): 97 - 106
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (777 KB) |  | HTML iconHTML  

    Large variations in the execution times of algorithms characterize many cyber-physical systems (CPS). For example, variations arise in the case of visual object-tracking tasks, whose execution times depend on the contents of the current field of view of the camera. In this paper, we study such a scenario in a small Unmanned Aerial Vehicle (UAV) system with a camera that must detect objects in a variety of conditions ranging from the simple to the complex. Given resource, weight and size constraints, such cyber-physical systems do not have the resources to satisfy the hard-real-time requirements of safe flight along with the need to process highly variable workloads at the highest quality and resolution levels. Hence, tradeoffs have to be made in real-time across multiple levels of criticality of running tasks and their operating points. Specifically, the utility derived from tracking an increasing number of objects may saturate when the mission software can no longer perform the required processing on each individual object. In this paper, we evaluate a new approach called ZS-QRAM (Zero-Slack QoS-based Resource Allocation Model) that maximizes the UAV system utility by explicitly taking into account the diminishing returns on tracking an increasing number of objects. We perform a detailed evaluation of our approach on our UAV system to clearly demonstrate its benefits. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimal Cross-Layer Design of Sampling Rate Adaptation and Network Scheduling for Wireless Networked Control Systems

    Publication Year: 2012 , Page(s): 107 - 116
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (997 KB) |  | HTML iconHTML  

    Wireless Networked Control Systems (NCS) are increasingly deployed to monitor and control Cyber-Physical Systems (CPS). To achieve and maintain a desirable level of performance, NCS face significant challenges posed by the scarce wireless resource and network dynamics. In this paper, we consider NCS consisting of multiple physical plant and digital controller pairs communicating over a multi-hop wireless network. The control objective is that the plants follow the reference trajectories provided by the controllers. This paper presents a novel optimization formulation for minimizing the tracking error due to (1) discretization and (2) packet delay and loss. The optimization problem maximizes a utility function that characterizes the relationship between the sampling rate and the capability of disturbance rejection of the control system. The constraints come from the wireless network capacity and the delay requirement of the control system. The solution leads to a joint design of sampling rate adaptation and network scheduling, which can be naturally deployed over existing networking systems which have a layered architecture. Based on a passivity-based control framework, we show that the proposed cross-layer design can achieve both stability and performance optimality. Simulation studies conducted in an integrated simulation environment consisting of Matlab/Simulink and ns-2 demonstrate that our algorithm is able to provide agile and stable sampling rate adaptation and achieve optimal NCS performance. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Defining CPS Challenges in a Sustainable Electricity Grid

    Publication Year: 2012 , Page(s): 119 - 128
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (618 KB) |  | HTML iconHTML  

    Cyber-Physical Systems (CPS) are characterized as complex distributed systems exhibiting substantial uncertainty due to interactions with the physical world. Today's electric grids are often described as CPS because a portfolio of distributed supplies must be dispatched in real-time to match uncontrolled, uncertain demand while adhering to constraints imposed by the intervening transmission and distribution network. With the increased control complexity required by deep penetration of fluctuating renewable supplies, the grid becomes more profoundly a CPS and needs to be addressed as a system. In this evolving CPS, a large fraction of supply is under-actuated, a substantial portion of demand needs to become dispatch able, interactions among distributed elements are no longer unidirectional, and operating requirements of elements are more dynamic. To more sharply define these CPS challenges, we obtain a yearlong, detailed measurement of the real-time blend of supplies on the primary California grid dispatched to meet current demand and then scale the solar and wind assets, preserving uncontrolled weather effects, to a level of penetration associated with California's 2050 GHG targets. In this representation of a future sustainable grid, we assess the impact of demand shaping, storage, and agility on the reconstituted supply portfolio, characterize resulting duration curves and ramping, and investigate the distributed control and management regime. We articulate new operational and market opportunities and challenges that may materialize from intermittent periods of abundance and scarcity in the overall energy network. We find that in a sustainable grid, lulls in renewable production during winter are more critical than peaks in demand during summer, capacity for load shifting and energy storage are more valuable as renewables penetration increases, and that grid balancing requires integrated management of supply and demand resources. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Multi-scale Integration of Physics-Based and Data-Driven Models in Power Systems

    Publication Year: 2012 , Page(s): 129 - 137
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (462 KB) |  | HTML iconHTML  

    The major subject of this paper is the introduction and testing of a new modeling paradigm necessary for enabling sustainable performance of electric energy systems. In previous work we have identified major challenges to systematically modeling distributed, non-uniform resources emerging in power grids. Today's modeling of electric energy systems is either entirely based on first principles which suffers significantly from the ever-increasing complexity of non-uniform devices, or is purely based on computer science data-driven approaches which lose the fundamental physical insights of electric power networks. Therefore, it is very difficult with today's modeling practices to integrate distributed non-uniform resources using both first-principle and data driven approaches in large-scale cyber-physical energy systems. In sharp contrast, this paper presents a holistic multi-scale modeling approach by combing advances from (1) physics based modeling of emerging distributed resources (e.g. wind generation and storage devices), and (2) data-driven modeling of load resources. With both physics-based models of distributed resources and data-driven models of flexible demands, key parameters are abstracted and identified from the detailed dynamical models necessary for the multi-scale power system operations. The proposed modeling framework is tested using realistic phasor measurement unit data obtained from Electric Reliability Council of Texas (ERCOT). View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Pack Sizing and Reconfiguration for Management of Large-Scale Batteries

    Publication Year: 2012 , Page(s): 138 - 147
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (428 KB) |  | HTML iconHTML  

    Battery systems for electric vehicles (EVs) or un-interruptible micro-grids-prototypical cyber-physical systems (CPSs)-are usually built with several hundreds/thousands of battery cells. How to deal with the inevitable failure of cells quickly and cost-effectively for vehicle warranty or uninterruptible service, for instance, is key to the development of large-scale battery systems. Use of extra (redundant/backup) cells to cope with cell failures must be minimized so as to make the target systems cheaper and lighter, while meeting the reliability requirement that is directly related to, for example, the vehicle warranty. Existing reconfigurable battery systems do not scale well because they incur a long delay in properly setting a large number of switches to bypass faulty cells or adapting to dynamically changing power demands in large battery systems for such applications as EVs. In this paper, we propose a scalable solution, not only to reduce the required number of backup cells and the total cost of a battery system, but also to facilitate recovery from cell failures and adapt to changing power demands while increasing battery utilization. Specifically, we optimize the pack-size by striking a balance between various types of cost in order to reduce the overall cost. We also configure battery packs and optimize their connection topology, reducing delays in failure recovery and power reallocation. Our in-depth evaluation has shown that the time to recover from cell failures remains constant irrespective of the number of cells involved, which is important to scalability. The proposed pack-sizing also reduces the cost and the size of battery systems. Moreover, fast power reallocation is achieved by utilizing prior knowledge of power usage patterns. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Model-Driven Performance Analysis of Large Scale Irrigation Networks

    Publication Year: 2012 , Page(s): 151 - 160
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (998 KB) |  | HTML iconHTML  

    Irrigation networks play a fundamental part in the agriculture system of various countries. In the wake of global environmental challenges and economic competition, efficient use of water resources has become extremely important. This can only be achieved by developing smarter control infrastructures for irrigation networks, via the incorporation of communication and computation technologies. Thus, future irrigation networks represent a prime example of cyber physical systems. Effective operation of these complex cyber physical systems is not possible with conventional methods and requires unprecedented levels of automation and decision-support tools. We argue that these cyber physical systems will require a complete model-driven toolset for effective operation. As a first step towards that tool flow, we have developed a model-driven simulation infrastructure for irrigation networks. In the future, we propose to complete the toolset by developing a model-driven configuration infrastructure. Our contributions in this paper include the development of a domain-specific modeling language (DSML) for irrigation networks, implementation of this DSML in Generic Modeling Environment (GME), and automatic simulator M-file generation capability from the DSML-based case diagram of an arbitrary irrigation network. Moreover, we present case studies of water distribution and flood management to show the utility as well as the effectiveness of our approach. We also present the performance of our toolset for the realistic scenario of irrigation networks in Pakistan. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Parametrized Verification of Distributed Cyber-Physical Systems: An Aircraft Landing Protocol Case Study

    Publication Year: 2012 , Page(s): 161 - 170
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (313 KB) |  | HTML iconHTML  

    In this paper, we present the formal modeling and automatic parameterized verification of a distributed air traffic control protocol called the Small Aircraft Transportation System (SATS). Each aircraft is modeled as a timed automaton with (possibly unbounded) counters. SATS is then described as the composition of N such aircraft, where N is a parameter from the natural numbers. We verify several safety properties for arbitrary N, the most important of which is separation assurance, which ensures that no two aircraft may ever collide. The verification methodology relies on computing the set of backward reachable states from the set of unsafe states to a fixed point, and checking emptiness of the intersection of these reachable states and the initial set of states. We used the Model Checker Modulo Theories (MCMT) tool, which implements this technique. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.