Future Cyber-physical Systems Research Articles

The Support of MISRA C++ Analyzer for Reliability of Embedded Systems

Cyber-Physical Systems (CPS) are increasingly used in many complex applications, such as autonomous delivery drones, the automotive CPS design, power grid control systems, and medical robotics. However, existing programming languages lack certain design patterns for CPS designs, including temporal semantics and concurrency models. Future research directions may involve programming language extensions to support CPS designs. On the other hand, JSF++, MISRA, and MISRA C++ are providing specifications intended to increase the reliability of safety-critical systems. This article also describes the development of rule checkers based on the MISRA C++ specification using the Clang open-source tool, which allows for the annotation of code and the easy extension of the MISRA C++ specification to other programming languages and systems. This is potentially useful for future CPS language research extensions to work with reliability software specifications using the Clang tool. Experiments were performed using key C++ benchmarks to validate our method in comparison with the well-known Coverity commercial tool. We illustrate key rules related to class, inheritance, template, overloading, and exception handling. Open-source benchmarks that violate the rules detected by our checkers are also illustrated. A random graph generator is further used to generate diamond case with multiple inheritance testdata for our software validations. The experimental results demonstrate that our method can provide information that is more detailed than that obtained using Coverity for nine open-source C++ benchmarks. Since the Clang tool is widely used, it will further allow developers to annotate their own extensions.

Energy-Resilient Real-Time Scheduling

Embedded nodes in future cyber-physical systems are mostly self-powered, scavenging their required energy from the environment. The environmental sources of energy are usually variable, so that some prediction methods are employed to proactively adapt to the variable harvesting energy. However, prediction errors may surprise the system with some unpredicted changes, needing appropriate reactions. We consider an energy-harvesting real-time system with periodic tasks of multiple performance levels. An energy-resilient scheduler is proposed for the system to react to the unpredicted changes such that the system is survivable, recovers from such a change in a timely manner, and appropriately controls its performance degradation. After the recovery, however, the energy-resilient scheduler preserves the system survivability and maximizes its performance in a prediction time horizon, while it will be ready for another surprise. We provide some theoretical properties and a feasibility test which are used in the design of the energy-resilient scheduler. Our simulations show that the proposed resilient scheduler outperforms well-known performance maximization methods, effectively approximates the optimal solution, and reacts appropriately against surprises of high severity.

Non-intrusive musculoskeletal disorders risk assessment towards an integration in human operators’ Digital Twins

The digital twin of human operators is an important aspect of future cyber-physical production systems. Among the various usage of this twin, the possibility to assess the health of the operator, especially fatigue and musculoskeletal disorders, is a major stake for future organizations. If this problem is often dealt with in the case of repetitive operations, mostly through an ergonomic perspective, it is much more difficult to evaluate the impact of non-repetitive operations on the health of the operators. This study aims at providing a first step to this objective, by exhibiting the correlation between ergonomic evaluations of operations difficulty with the MUSKA MSD methodology and the pain felt by the operators through a longitudinal study performed through NORDIC questionnaires. The results show that the results of ergonomic evaluation of operations can be used in a stochastic parametric model to assess the evolution of pains of the operators on long time scales.

Multi-Access Edge Computing assisted ultra-low energy scheduling and harvesting in multi-hop Wireless Sensor and Actuator Network for energy neutral self-sustainable Next-gen Cyber-Physical System

Energy Neutrality is the need of the hour for future Cyber-physical infrastructure. Many past research works suggest low duty cycle networking for energy-efficient wireless sensor network; however, research problem still persist as these proposals have some practical deployment bottlenecks like sleep-latency and may trade-off with data-fidelity and Quality-of-Service (QoS) parameters. The research objective of this work is to propose a novel design for wireless sensor–actuator mote system to minimize energy consumption and compensate with harvesting to achieve energy neutral operation in multi-hop Wireless Sensor and Actuator Network (WSAN); A network scenario that is much needed for Internet of Thing (IoT) applications in future ready Next-gen Cyber Physical System (NG-CPS). In this paper, we have proposed a novel state-of-the-art Multi-Access/Mobile Edge Computing (MEC) assisted Low-Duty-Cycle Scheduling of Trans-Receiver for Store-Process-Then-Forward (LDCS-TR-SPTF) scheme in multi-hop WSAN for reducing the overall energy consumption. In addition to energy conservation, we have also proposed a hybrid harvesting to compensate energy to achieve energy neutral self-sustainable NG-CPS. The proposed novel LDCS-TR-SPTF has been implemented on multiple custom-made sensor–actuator motes equipped with ARM-based System-on-Chip (SoC) and IEEE 802.11 network interface. These motes are working both as end-nodes and relay nodes in a multi-hop WSAN testbed scenario for testing and validation of our proposed scheme. The results are promising with an overall energy conservation of 49.1% using our novel LDCS-TR-SPTF in comparison to stock IEEE 802.11. We have implemented solar energy harvester on wireless sensor–actuator motes to compensate the reduced energy consumption and achieved complete energy-neutrality. Motes are completely energy-autonomous in multi-hop WSAN scenario by eliminating the need of access to external power-grid for future cyber–physical system.

Age of Information in CSMA-Based Networks With Bursty Update Traffic

Exchanging status information between closely located mobile agents is an underlying process in numerous future Cyber Physical System (CPS). Real-time updates including positions of neighboring nodes is performed when, for example, autonomous vehicles execute a cooperative maneuver, industrial robots collaborate with each other on a task, or Unmanned Aerial Vehicles (UAVs) execute a mission in a swarm. For the design of networked automatic control strategies in these scenarios, it is essential to understand the performance of such Machine-to-Machine (M2M) communications from the information freshness perspective. To this end, we introduce a mathematical framework which allows characterizing the Age of Information (AoI) in networks governed by the Carrier-Sense Multiple Access (CSMA) protocol. Differently from existing work, we take into account the fact that update packets sent by mobile nodes are not necessarily periodic, since packet triggering is often coupled with agents’ mobility. Our approach is based on the assumption that diverse mobility-triggered message generation patterns can be modeled by a wide class of update traffic arrival processes. We apply Discrete Markovian Arrival Process (DMAP), which is a versatile arrival model able to fit arrival patterns that are modulated by a finite state machine, including bursty traffic. We develop an accurate and efficient analytical model of nodes exchanging one-hop broadcast update messages with bursty arrivals to evaluate the moments as well as entire probability distribution of several performance metrics, including AoI. An asymptotic analysis for large networks suggests a simple way to control the update message rate to minimize the AoI. We show that the optimal update rate that minimizes the mean AoI coincides with the optimum of the wireless channel utilization. Numerical examples point out that the asymptotic theory provides accurate predictions also for small values of the number of nodes.

A survey of cyber-physical system implementations of real-time personalized interventions

Advances in sensor technology and machine learning as well as the widespread use of smartphones are shifting the focus of healthcare. Emerging paradigms such as cyber-physical systems (CPSs) make possible the transition from reactive to preventive care. CPSs can be implemented to achieve effective mobile health solutions and to provide sophisticated new mechanisms to monitor an individual’s state in real-time via the use of sensors and mobile devices. Despite the significant potential impact of such systems, their implementation poses a range of complex technical challenges. This article surveys the state-of-the-art in implementations of CPSs for real-time personalized interventions. A general three layer architecture which can be used to consider current implementations is first presented along with a description of its main components. We also propose a three level taxonomy in accordance with the system capabilities. Then, the principal technical challenges, human-machine interaction challenges and future directions are discussed. Fifteen of the state-of-the-art implementations are qualitatively evaluated in terms of sensor capabilities, just-in-time reaction, interruptibility, and adherence, among other characteristics. By reviewing the state-of-the-art of the systems that have been built to-date, the focus of the review is to summarize current technical challenges and future opportunities for both future CPS implementers and behavioral scientists designing CPS for personalized interventions.

Integrisanje žena u savremene projekte iz oblasti sajber-fizičkih sistema

Nowadays, in the era of the fourth industrial revolution, it is necessary to find the position of women population in designing and realization of recent cyber-physical systems (CPS). These complex systems contain physical and mechanical elements which are automatically driven and controlled by computers. One of the most important project in CPS which would be realized in a short time is the autonomous self-driving car. Investigation done in the world show that the most of women are not informed about this project and only a few of them are the part of project teams. In this paper the result of interview of women population in Serbia on self-driving car is considered. It is obtained that most of women are not included in such project, and is not ready to accept it. Explanation is that in the project the specificity due to difference between poles is not inbult in the project. It is mostly seen in the algorithms for making decisions of self-driving car with artificial intelligence. Female have the opinion that they have to be incorporated in such multidisciplinary projects which are of importance for the whole world population. The aim of the paper is to show that the inclusion of women in the future CPS projects is necessary as a fundamental aspect of acceptance CPS in everyday life.

Cyber-physical systems research and education in 2030: Scenarios and strategies

Future cyber-physical systems (CPS), such as smart cities, collaborative robots, autonomous vehicles or intelligent transport systems, are expected to be highly intelligent, electrified, and connected. This study explores a focal question about how these new characteristics may affect the education and research related to CPS in 2030, the date identified by the United Nations to achieve the Agenda for Sustainable Development. To this end, first, we have conducted a trend spotting activity, seeking to identify possible influencing factors that may have a great impact on the future of CPS education and research.These factors were clustered in a total of 12 trends – four certainties; namely connectivity, electrification, data and automation – and eight uncertainties; namely intelligence, data ethics, labour market, lifelong learning, higher education, trust in technology, technological development speed, and sustainable development goals.After that, two of the eight uncertainties are identified and used to construct a scenario matrix, which includes four scenarios. These two uncertainties – the so-called strategic uncertainties – are: fulfilment of sustainable development goals and the nature of the technological development, respectively. These two important uncertainties are considered to build the scenarios due to their potential impact on the research and education of CPS. For instance, sustainable development goals are significant targets for many initiatives, organisations and countries. While 2030 is the deadline to achieve these goals, the relationship between the sustainable development goals related to CPS research and education is not studied well. Similarly, the speed of technological development is seen as a driving force behind future CPS. However, the effect of this speed to CPS research and education environment is not known.Different outcomes of the chosen two uncertainties are, then, combined with the remaining trends and uncertainties. Consequently, four scenarios are derived. The Terminator scenario illustrates a dystopian future where profit is the driving force behind technological progress and sustainable development goals are not accomplished. In contrast, The Iron Giant scenario represents the successful implementation of the sustainable development goals where technological development is the force behind the accomplishment of these goals. The scenario called Slow Progress represents a future where gradual technological improvements are present, but sustainability is still not seen as concerning the issue. The Humanist scenario illustrates a future where slow technological development is happening yet sustainable development goals are successfully implemented.Finally, the scenarios are used to initiate discussions by illustrating what the future of research and education could look like and a list of strategies for future CPS research and education environments is proposed. To this end, we invite educators, researchers, institutions and governments to develop the necessary strategies to enable data-orientated, continuous, interdisciplinary, collaborative, ethical, and sustainable research and education by improving digital fluency, advancing digital equality, contributing to new ways of teaching complex thinking, expanding access to learning platforms and preparing next generations to adapt for a rapidly changing future of work conditions.

Modeling interconnected ICT and power systems for resilience analysis

Increasing interdependencies between power and ICT systems amplify the possibility of cascading failures. Resilience against such failures is an essential property of modern and sustainable power systems and networks. To assess the resilience and predict the behaviour of a system consisting of interdependent subsystems, the interconnection requires adequate modeling. This work presents an approach to model and determine the state of these so-called interconnectors in future cyber-physical energy systems with strongly coupled ICT and power systems for a resilience analysis. The approach can be used to capture the impact of various parameters on system performance upon suitable modification. An hierarchical modeling approach is developed with atomic models that demonstrate the interdependencies between a power and ICT system. The modeling approach using stochastic activity nets is applied to an exemplary redispatch process in a cyber-physical energy system. The performance of an interconnector when facing limited performance from the ICT subsystem and its subsequent impact on the power system is analysed using the models. The state of the interconnector, as well as the service level are mapped to a resilience state-space diagram. The representation of system state on the resilience state-space diagram allows interpretation of system performance and quantification of resilience metrics.

Introduction to the Special Issue on Evolving IoT and Cyber-Physical Systems: Advancements, Applications, and Solutions

Introduction to the Special Issue on Evolving IoT and Cyber-Physical Systems: Advancements, Applications, and Solutions

Cyber-Physical Systems Security Education Through Hands-on Lab Exercises

Cyber-physical systems (CPSs), due to interacting directly with the physical environment, must be dependable, and in particular must be secure. This article shows how to integrate systems security topics into the educational program for future CPS engineers.

I Think Therefore You Are

Cyber-physical systems operate in our real world, constantly interacting with the environment and collaborating with other systems. The increasing number of devices will make it infeasible to control each one individually. It will also be infeasible to prepare each of them for every imaginable rapidly unfolding situation. Therefore, we must increase the autonomy of future Cyber-physical Systems. Making these systems self-aware allows them to reason about their own capabilities and their immediate environment. In this article, we extend the idea of the self-awareness of individual systems toward networked self-awareness . This gives systems the ability to reason about how they are being affected by the actions and interactions of others within their perceived environment, as well as in the extended environment that is beyond their direct perception. We propose that different levels of networked self-awareness can develop over time in systems as they do in humans. Furthermore, we propose that this could have the same benefits for networks of systems that it has had for communities of humans, increasing performance and adaptability.

Cyber-physical platform development and implementation for industry 4.0

AbstractIndustry 4.0 is referred as the fourth industrial revolution that represents the information intensive transformation of industrial automation and manufacturing processes. Cyber-physical systems (CPS) are building blocks in Industry 4.0 and part of the Industry 4.0 vision. This paper presents a cyber-physical platform development and implementation strategy for Industry 4.0 applications. It has been considered a cyber-physical platform model (CPP) built upon hardware reconfigurable technology based on a Field Programmable Gate Array (FPGA) processor framework. The development strategy exploits the full benefits enabled by reconfigurable hardware, such as scalability of complex systems, platform-based design approach, adaptive processing, real-time constrains management, or high performance prototyping capabilities. The implemented experimental setup also combines major advantages of both the hardware and software platform-based design trends in Industry 4.0. In this endeavor, the used software toolkit comprises the entire system complexity as a high performance integration layer. The presented design method and implementation strategy can serve as rough orientation for future CPS research and development activities.

An Architecture for Highly Reliable Fault-Tolerant Adaptive Distributed Embedded Systems

With increased demand for carrying out critical operations in unpredictable environments, critical adaptive distributed embedded systems will play a key role in future cyberphysical systems. Based on a flexible real-time Ethernet network, we propose a complete architecture that includes mechanisms to deal with faults for high reliability.

Current and future requirements to industrial analytical infrastructure\u2014part 2: smart sensors

Complex processes meet and need Industry 4.0 capabilities. Shorter product cycles, flexible production needs, and direct assessment of product quality attributes and raw material attributes call for an increased need of new process analytical technologies (PAT) concepts. While individual PAT tools may be available since decades, we need holistic concepts to fulfill above industrial needs. In this series of two contributions, we want to present a combined view on the future of PAT (process analytical technology), which is projected in smart labs (Part 1) and smart sensors (Part 2). Part 2 of this feature article series describes the future functionality as well as the ingredients of a smart sensor aiming to eventually fuel full PAT functionality. The smart sensor consists of (i) chemical and process information in the physical twin by smart field devices, by measuring multiple components, and is fully connected in the IIoT 4.0 environment. In addition, (ii) it includes process intelligence in the digital twin, as to being able to generate knowledge from multi-sensor and multi-dimensional data. The cyber-physical system (CPS) combines both elements mentioned above and allows the smart sensor to be self-calibrating and self-optimizing. It maintains its operation autonomously. Furthermore, it allows—as central PAT enabler—a flexible but also target-oriented predictive control strategy and efficient process development and can compensate variations of the process and raw material attributes. Future cyber-physical production systems—like smart sensors—consist of the fusion of two main pillars, the physical and the digital twins. We discuss the individual elements of both pillars, such as connectivity, and chemical analytics on the one hand as well as hybrid models and knowledge workflows on the other. Finally, we discuss its integration needs in a CPS in order to allow its versatile deployment in efficient process development and advanced optimum predictive process control.

Mobile Wi-Fi Based Scheduling of Cyber-Physical Systems in Healthcare

Wireless Body Area Networks (WBANs) and Wireless Local Area Networks (WLANs) have been widely regarded as solution providers for future Cyber-Physical Systems (CPS)-based ehealthcare amenities. The IEEE 802.11 standard specifies media access protocols in wireless networks, along with channel access methods. WBANs are expected to improve the existing healthcare services significantly, but several research challenges also have to be tackled for apt utilization of the technology. Guarantee of Quality-of-Service (QoS) differentiation between various health parameters, such as temperature and blood pressure, during mobility is a major challenge for the provision of ehealthcare services. The scheme proposed in this paper for the Mobile Wi-Fi based connectivity of WBANs is designed to provide QoS-based priorities for ehealthcare subscribers by altering the Contention Window (CW) for different applications of patient health monitoring. The relationship between CW and QoS is utilized to achieve efficient resource assignment. Three different health parameters, i.e., ECG (Electrocardiogram), BP (blood pressure) and temperature. are monitored using medical CPS in this work. The performance evaluation results, such as end-to-end packet delay and throughput for various data traffic classes reveal that the proposed scheme improves QoS provision.

A Trustworthy Communication Hub for Cyber-Physical Systems

The motivation for this research arises from the challenges in the trustworthy communications related operation of cyber-physical systems (CPS), especially in the energy and mobility domains. The increasing amount of distributed energy resources (DERs) of prosumers and electric vehicles requires new ways for CPS communications to enable information exchanges for smart operation in peak consumption hours and balancing power levels in the energy grids in order to lower the energy cost. The huge number of mobile appliances and the related service providers do not serve properly the privacy of the owners, owing to the vertical silo type of operating model in industries. As the results of this research, we provide a trustworthy communication hub for CPS (CPS hub) for solving the challenges related to trustworthy communications between physical resources owned by different stakeholders. The CPS hub realizes the communication spaces concept, and enables combined trust and communications processes when dynamic resources owned by different stakeholders are exchanging information. The evaluations showed that the provided CPS hub enable information exchanges between distributed energy resources of different stakeholders, so that they can join the aggregation process for more flexible and efficient resource usage in energy markets. The CPS hub enable interaction between heterogeneous physical devices of multiple stakeholders to exchange information so that, for example, authorities can see the situation in the emergency area and, simultaneously, the policies of the owners can be taken into concern. Despite limited evaluation scenarios, it is shown that consideration of the ownership issues in the trustworthy communication for information exchanges between heterogeneous physical resources (devices) is possible and feasible. Several future research items, such as, for example, scalability; real-time and streams based operation; as well as consideration of the security, privacy, trust, and safety challenges, were detected. However, the evaluations showed that the constructed CPS hub contribute a set of very essential technical enablers for future smart CPS systems and create strong a basis for such future research towards a future smart society.

Methods for Large-Scale Time-Triggered Network Scheduling

Future cyber–physical systems may extend over broad geographical areas, like cities or regions, thus, requiring the deployment of large real-time networks. A strategy to guarantee predictable communication over such networks is to synthesize an offline time-triggered communication schedule. However, this synthesis problem is computationally hard (NP-complete), and existing approaches do not scale satisfactorily to the required network sizes. This article presents a segmented offline synthesis method which substantially reduces this limitation, being able to generate time-triggered schedules for large hybrid (wired and wireless) networks. We also present a series of algorithms and optimizations that increase the performance and compactness of the obtained schedules while solving some of the problems inherent to segmented approaches. We evaluate our approach on a set of realistic large-size multi-hop networks, significantly larger than those considered in the existing literature. The results show that our segmentation reduces the synthesis time by up to two orders of magnitude.

When Time Matters: Predictive Mission Planning in Cyber-Physical Scenarios

Future cyber-physical systems are expected to exploit autonomous robots to accomplish dangerous or complex missions composed of several tasks. A critical aspect is the availability of suitable mission planning strategies to react against external disturbances or hardware outages. Unfortunately, classic planning approaches may not take advantage of the ability of cyber-physical systems to collect a variety of information from sensors or IoT nodes, which can be used to forecast future events. Therefore, this paper proposes the adoption of predictive control for mission planning. Specifically, predictive control is used to compute online the best time instants when to change the assignment of tasks to robots by solving finite-horizon optimal control problems. The simulation results performed in comparison with “legacy” reactive and proactive strategies showcase the superiority of the proposed approach, especially in scenarios characterized by large disturbances.

How to Deal with the Complexity of Future Cyber-Physical Systems?

Cyber-Physical Systems (CPS) integrate computation, networking and physical processes to produce products that are autonomous, intelligent, connected and collaborative. Resulting Cyber-Physical Systems of Systems (CPSoS) have unprecedented capabilities but also unprecedented corresponding technological complexity. This paper aims to improve understanding, awareness and methods to deal with the increasing complexity by calling for the establishment of new foundations, knowledge and methodologies. We describe causes and effects of complexity, both in general and specific to CPS, consider the evolution of complexity, and identify limitations of current methodologies and organizations for dealing with future CPS. The lack of a systematic treatment of uncertain complex environments and “composability”, i.e., to integrate components of a CPS without negative side effects, represent overarching limitations of existing methodologies. Dealing with future CPSoS requires: (i) increased awareness of complexity, its impact and best practices for how to deal with it, (ii) research to establish new knowledge, methods and tools for CPS engineering, and (iii) research into organizational approaches and processes to adopt new methodologies and permit efficient collaboration within and across large teams of humans supported by increasingly automated computer aided engineering systems.