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Time synchronization is essential for the correct and consistent operation of automation systems. An inaccurate analysis being a consequence of improper synchronization, can affect automation functions, e.g., by producing false commands and warnings. Industrial systems are evolving from the rigid automation pyramid to a flexible and reconfigurable architecture due to market evolution. The new trends in Cyber-Physical-Systems (CPS), Industry 4.0, and Internet of Things (IoT) are enabling this evolution. Citing a need to understand the future synchronization requirements, this paper envisions the architecture, communication network, and applications of future automation systems. Built on this vision, the paper derives the future needs of synchronization and analyzes them with state-of-art synchronization means. Based on the analysis, we envision the future of synchronization systems for automation systems.

Vehicle platooning is a promising technology to save the road capacity and also fuel consumption by reducing the distance between the vehicles in the platoon. The closer the cars are to each other, the closer we are to the goals. But, this will increase the need for safety verification. In this paper we use formal methods to verify safety distance in a platoon. To do so, we present a formal actor-based model for a vehicle platoon which incorporates vehicle dynamics and communication protocol. Also, we present a method to do the analysis based on model checking that applies mathematical analysis to reduce the state space. The method uses an upper bound and a lower bound value as network delay, and verifies if a specified vehicle in a platoon has enough distance to the leader during its traveling. © 2020 IEEE., Conference code: 163774; Export Date: 29 October 2020; Conference Paper; CODEN: 85ROA

Wired networks are deployed in scenarios requiring the highest levels of performance in terms of reliability and timeliness. Unfortunately, broken wires might permanently compromise the network operation unless fault tolerance mechanisms are in place. Fault tolerance is commonly achieved by replicating the wired network components, but this paper examines the use of a wireless backup network, since the wireless physical layer (PHY) is not expected to display permanent failures due to broken wires. Two mechanisms at medium access control (MAC) level are presented to take advantage of the wireless backup network: one allocating redundancy statically and one dynamically. Without loss of generality, redundancy is applied using the standard mechanisms from IEEE 802.3 (Ethernet) and IEEE 802.11 (Wi-Fi). The performance increase added by the backup network is studied both analytically and by simulation, showing considerable improvements in a very compromised midsize wired network. © 2020 IEEE., Conference code: 163774; Export Date: 29 October 2020; Conference Paper; CODEN: 85ROA

Automation and robotics are two enablers for developing the Smart Factory of the Future, which is based on intelligent machines and collaboration between robots and humans. Especially in final assembly and its material handling, where traditional automation is challenging to use, collaborative robot (cobot) systems may increase the flexibility needed in future production systems. A major obstacle to deploy a truly collaborative application is to design and implement a safe and efficient interaction between humans and robot systems while maintaining industrial requirements such as cost and productivity. Advanced and intelligent control strategies is the enabler when creating this safe, yet efficient, system, but is often hard to design and build.This paper highlights and discusses the challenges in meeting safety requirements according to current safety standards, starting with the mandatory risk assessment and then applying risk reduction measures, when transforming a typical manual final assembly station into an intelligent collaborative station. An important conclusion is that current safety standards and requirements must be updated and improved and the current collaborative modes defined by the standards community should be extended with a new mode, which in this paper is refereed to the deliberative planning and acting mode.

This paper provides a systematic three-stage methodology for migrating complex real-Time industrial software systems from single-core to multi-core computing platforms. Single-core platforms have limited computational capabilities that prevent integration of computationally demanding applications such as image processing within the existing system. Modern multi-core processors provide increased computing capacity and allow the parallel execution of different applications within the system. However, this transition is non-Trivial and requires a systematic and well-defined migration process. This paper reviews some of the existing migration methods and provides a systematic multi-phase migration process with emphasis on software architecture recovery and transformation to explicitly address the timing and dependability attributes expected of industrial software systems. © 2020 IEEE., Conference code: 160961; Export Date: 6 August 2020; Conference Paper

When a hazardous situation approaches, the semi-autonomous vehicle opts for the driver as a fallback solution, unaware of the driver's readiness. During such a situation, autonomy misuse can occur when a driver becomes over-reliant on autonomous driving. For handling the hazardous event, controllability is paramount. We postulate that semi-autonomous vehicles decline their consideration in understanding the drivers' focus on the vehicle and the road. To examine the drivers' focus on the vehicle and the road we uphold that the vehicle must initiate exploring the drivers' situation awareness for the readiness, which could feasibly tune the ISO 26262 controllability. In this paper, we propose a physiology-based driver situation awareness for the readiness model through the driver's stress and drowsiness estimation. In addition, we boost the situation awareness for the readiness of the driver by enabling frequent interaction between the driver and the vehicle managing system. © 2020 IEEE., Conference code: 161536; Conference Paper; CODEN: IVTCD

In this paper we explain how the isolation or decoupling of actors can help in developing efficient analysis techniques. The Reactive Object Language, Rebeca, and its timed extension are introduced as actor-based languages for modeling and analyzing distributed systems. We show how floating-time transition system can be used for model checking of timed actor models when we are interested in event-based properties, and how it helps in state space reduction. We explain how the model of computation of actors helps in devising an efficient state distribution policy in distributed model checking. We show how we use Rebeca to verify the routing algorithms of mobile adhoc networks. The paper is written in a way to make the ideas behind each technique clear such that it can be reused in similar domains.

The advanced production systems are composed of separate and distinct systems that operate in both isolation and conjunction, and therefore forms the System-of-Systems (SoS). However, a lot of production systems are classified as safety-critical, for example, due to the interactions between machines and involved materials. From the safety perspective, besides the behaviour of an individual system in SoS, the emergent behaviour of systems that comes from their individual actions and interactions must be considered. An unplanned event or sequence of events in safety-critical production systems may results in human injury or death, damage to machines or the environment. This paper focuses on the construction equipment domain, particularly the quarry site, which solely produce dimension stone and/or gravel products. The principal contribution of this paper is SoS hazard identification and mitigation/elimination for the electric quarry site for which the combination of guide words based collaborative method Hazard and Operability (HAZOP) and Fault Tree Analysis (FTA) are used. The published studies on HAZOP and FTA techniques have not considered the emergent behaviours of different machines. The applicability of particular techniques is demonstrated for individual and emergent behaviours of machines used in the quarry operations, such as autonomous hauler, wheel loader, excavator and crusher.

This paper investigates the effects of various parameters of high priority traffic classes on the Best Effort (BE) traffic in the networks based on the IEEE Time Sensitive Networking (TSN) standards. In this regard, the paper discusses ongoing work and presents preliminary results using a TSN simulator. The results indicate that several parameters of the high priority traffic such as periods, offsets and preemption modes can have a significant impact on the quality of service (e.g., guaranteed message delivery and message delays) of the BE traffic.

Probabilistic timing analysis techniques have been proposed for real-time systems to remedy the problems that deterministic estimates of the task's Worst-Case Execution Time and Worst-Case Response-Time can be both intractable and overly pessimistic. Often, assumptions are made that a task's response time and execution time probability distributions are independent of the other tasks. This assumption may not hold in real systems. In this paper, we analyze the timing behavior of a simple periodic task on a Raspberry Pi model 3 running Arch Linux ARM. In particular, we observe and analyze the distributions of wake-up latencies and execution times for the sequential jobs released by a simple periodic task. We observe that the timing behavior of jobs is affected by release events during the job's execution time, and of other processes running in between subsequent jobs of the periodic task. Using a data consistency approach we investigate whether it is reasonable to model the timing distribution of jobs affected by release events and intermediate processes as translations of the empirical timing distribution of non-affected jobs. According to the analysis, this paper shows that a translated distribution model of non-affected jobs is invalid for the execution time distribution of jobs affected by intermediate processes. Regarding the wake-up latency distribution with intermediate processes, a translated distribution model is improbable, but cannot be completely ruled out.

Several control methods have been proposed to stabilise riderless bicycles but they do not have sufficient simplicity for practical applications. This paper proposes a practical approach to model an instrumented bicycle as a combination of connected systems. Using this model, a PID controller is designed by a loop shaping method to stabilise the instrumented riderless bicycle. The initial results show that the bicycle can be stabilised when running on a roller. The work presented in this paper shows that it is possible to self stabilise a riderless bicycle using cascade PI/PID controllers.

The construction industry is today among the least automated industries with a long tradition of utilizing manual labour. Despite the potential benefits of automation, only a few examples of using robots to automate (parts of) construction have been presented over the past years. In this paper we present our ongoing work towards automated installation of reinforcement, a traditionally very heavy and labour intensive work. We use industrial robots and we discuss the potential benefits and challenges of such robotic automation in construction. Our overall goal is to achieve a fully automated robotic solution for flexible serial production of custom made non-identical reinforcement cages. In the paper we highlight and analyse the main challenges that must be addressed in order to reach a functioning and efficient solution.

This paper presents an adapter to link the Matlab/Simulink model of a custom braking system into an open-source road traffic simulator, namely SUMO. The traditional braking models in SUMO work on a coarser level, generally modeling the deceleration of the vehicle based on a single equation. Substituting this model with a detailed system allows adjustments on a very low level, including delays between components, the traction of individual tires, and controllers for the anti-locking system by simulating those in Simulink. Besides introducing the novel adapter linked into SUMO and discussing parameter fitting to mimic the behavior of the traditional braking system, this paper discusses the amount of performance deterioration as the price for simulating a more sophisticated braking system., SafeCOP - Safe Cooperating Cyber-Physical Systems using Wireless Communication

This paper presents an adapter to link the Matlab/Simulink model of a custom braking system into an open-source road traffic simulator, namely SUMO. The traditional braking models in SUMO work on a coarser level, generally modeling the deceleration of the vehicle based on a single equation. Substituting this model with a detailed system allows adjustments on a very low level, including delays between components, the traction of individual tires, and controllers for the anti-locking system by simulating those in Simulink. Besides introducing the novel adapter linked into SUMO and discussing parameter fitting to mimic the behavior of the traditional braking system, this paper discusses the amount of performance deterioration as the price for simulating a more sophisticated braking system., SafeCOP - Safe Cooperating Cyber-Physical Systems using Wireless Communication

This paper presents an adapter to link the Matlab/Simulink model of a custom braking system into an open-source road traffic simulator, namely SUMO. The traditional braking models in SUMO work on a coarser level, generally modeling the deceleration of the vehicle based on a single equation. Substituting this model with a detailed system allows adjustments on a very low level, including delays between components, the traction of individual tires, and controllers for the anti-locking system by simulating those in Simulink. Besides introducing the novel adapter linked into SUMO and discussing parameter fitting to mimic the behavior of the traditional braking system, this paper discusses the amount of performance deterioration as the price for simulating a more sophisticated braking system., SafeCOP - Safe Cooperating Cyber-Physical Systems using Wireless Communication

This paper presents an adapter to link the Matlab/Simulink model of a custom braking system into an open-source road traffic simulator, namely SUMO. The traditional braking models in SUMO work on a coarser level, generally modeling the deceleration of the vehicle based on a single equation. Substituting this model with a detailed system allows adjustments on a very low level, including delays between components, the traction of individual tires, and controllers for the anti-locking system by simulating those in Simulink. Besides introducing the novel adapter linked into SUMO and discussing parameter fitting to mimic the behavior of the traditional braking system, this paper discusses the amount of performance deterioration as the price for simulating a more sophisticated braking system., SafeCOP - Safe Cooperating Cyber-Physical Systems using Wireless Communication

This paper presents an adapter to link the Matlab/Simulink model of a custom braking system into an open-source road traffic simulator, namely SUMO. The traditional braking models in SUMO work on a coarser level, generally modeling the deceleration of the vehicle based on a single equation. Substituting this model with a detailed system allows adjustments on a very low level, including delays between components, the traction of individual tires, and controllers for the anti-locking system by simulating those in Simulink. Besides introducing the novel adapter linked into SUMO and discussing parameter fitting to mimic the behavior of the traditional braking system, this paper discusses the amount of performance deterioration as the price for simulating a more sophisticated braking system., SafeCOP - Safe Cooperating Cyber-Physical Systems using Wireless Communication

Road construction is a very large business segment, consuming enormous public funding every year and with significant environmental impacts. However, the rate of efficiency improvement during the last few decades has been negligible, whereas other industries, such as manufacturing, have seen very large improvements by applying automation and Leanbased flow optimization across the production system. In this paper, we outline a system-of-systems concept for road construction which applies similar principles as have previously proved successful in other industries. The paper identifies efficiency attributes and wastes in current practices, which lead to a conceptual solution that focuses on improved coordination of working machines. Technical elements from Industry 4.0 are considered as potential building blocks in this concept, identifying similarities and differences between the construction domain and other industries. Finally, challenges are identified, in particular within knowledge representation and information management.

This paper presents an adapter to link the Matlab/Simulink model of a custom braking system into an open-source road traffic simulator, namely SUMO. The traditional braking models in SUMO work on a coarser level, generally modeling the deceleration of the vehicle based on a single equation. Substituting this model with a detailed system allows adjustments on a very low level, including delays between components, the traction of individual tires, and controllers for the anti-locking system by simulating those in Simulink. Besides introducing the novel adapter linked into SUMO and discussing parameter fitting to mimic the behavior of the traditional braking system, this paper discusses the amount of performance deterioration as the price for simulating a more sophisticated braking system., SafeCOP - Safe Cooperating Cyber-Physical Systems using Wireless Communication

Long Short-Term Memory (LSTM) is one of the most popular and effective Recurrent Neural Network (RNN) models used for sequence learning in applications such as ECG signal classification. Complex LSTMs could hardly be deployed on resource-limited bio-medical wearable devices due to the huge amount of computations and memory requirements. Binary LSTMs are introduced to cope with this problem. However, naive binarization leads to significant accuracy loss in ECG classification. In this paper, we propose an efficient LSTM cell along with a novel hardware architecture for ECG classification. By deploying 5-level binarized inputs and just 1-level binarization for weights, output, and in-memory cell activations, the delay of one LSTM cell operation is reduced 50x with about 0.004% accuracy loss in comparison with full precision design of ECG classification.

The drones provide an active measure to identify, monitor, analyze and resolve risks of autonomous systems during operational phase. To date, however, the published studies have not considered them for managing risks in a dynamic manner. The capability to deal with unknowns and uncertainties during operational phase is regarded as essential to exploit the autonomous systems at their full potential. This paper targets the drone-based assurance of autonomous systems. The hazard and threat analyses are performed during design and development phase by using the Hazard and Operability (HAZOP) and Threat and Operability (THROP) techniques, respectively. Based on the analyses results, the safety and security requirements are derived. The assume-guarantee contracts are also derived for uncertainty sources; they are integrated in the blockchain-based smart contracts. The simulators are leveraged for performing the verification and validation as well as improving systems. For assuring safety and security during operational phase, the contracts derived for uncertainty sources are checked. In case of divergence, the drones provide assistance; otherwise, depending on the severity risk factor, system control is taken to avoid the mishap risk. The applicability of the proposed methodology is exemplified in the context of a quarry site production scenario.

A quarry site is used to produce gravel with different granularities based on the customer's needs. The production process consists of different stages that need to be planned in order to achieve high productivity and low cost. During the operation of the quarry site, the operating parameters change, and the site productivity could be affected, therefore, a replanning of the production is needed. This paper presents a real-time optimization model for production planning in a quarry site. The optimization model consists of three modules, a productivity monitoring module, a simulation model, and an optimization algorithm. The productivity monitoring module produces the site productivity based on the current operating parameters of the quarry site. Once the site productivity reaches a specific threshold, the optimization algorithm is run on an updated simulation model to find the optimal values of the site parameters. The proposed real-time optimization model is applied to a real quarry site simulated on a high-fidelity simulator. The case study shows that the proposed optimization model can effectively improve the productivity of the quarry site and hence reduces the wastes and improve environmental sustainability.

In the recent works that analyzed execution-time variation of real-time tasks, it was shown that such variation may conform to regular behavior. This regularity may arise from multiple sources, e.g., due to periodic changes in hardware or program state, program structure, inter-task dependence or inter-task interference. Such complexity can be better captured by a Markov Model, compared to the common approach of assuming independent and identically distributed random variables. However, despite the regularity that may be described with a Markov model, over time, the execution times may change, due to irregular changes in input, hardware state, or program state. In this paper, we propose a Bayesian approach to adapt the emission distributions of the Markov Model at runtime, in order to account for such irregular variation. A preprocessing step determines the number of states and the transition matrix of the Markov Model from a portion of the execution time sequence. In the preprocessing step, segments of the execution time trace with similar properties are identified and combined into clusters. At runtime, the proposed method switches between these clusters based on a Generalized Likelihood Ratio (GLR). Using a Bayesian approach, clusters are updated and emission distributions estimated. New clusters can be identified and clusters can be merged at runtime. The time complexity of the online step is $O(N^{2}+ NC)$ where N is the number of states in the Hidden Markov Model (HMM) that is fixed after the preprocessing step, and C is the number of clusters.

The paper introduces elements of a service based perspective of a scalable and dynamic automation system architecture. The approach is based on potentially multi-role devices (implementing node management, processing and networking functionalities) hosting a set of services requested by input nodes. In addition, artificial intelligence support is described to provide means of reaching deployment optimality and reliability. Formal approaches are deemed necessary for both verification of the artificial intelligence approach and of the resulting solutions. A model-based design path is complementary considered in order to lead to an increased efficiency in resource utilization, to lowering design efforts, and ensure a formally correct allocation of services, according to system requirements and constraints.

An evaluation of safety and security properties performed by an independent organisation can be an important step towards establishing trust in Automated Driving Systems (ADS), bridging the gap between the marketing portrayal and the actual performance of such systems in real operating conditions. However, due to the complexity of an ADS's behaviour and dangers involved in performing real environment security attacks, we believe assessments that can be performed with a combination of simulation and validation at test facilities is the way forward.In this paper, we outline an approach to derive test suites applicable to generic ADS feature classes, where classes would have similar capabilities and comparable assessment results. The goal is to support black box testing of such feature classes as part of an independent evaluation. By the means of co-simulation of post-attack behaviour and critical scenarios, we derive a representative set of physical certification tests, to gain an understanding of the interplay between safety and security. During the initial tests an ADS is subjected to various attacks and its reactions recorded. These reactions such as reduced functionality, fall back etc., together with relevant scenarios for the class is further analysed to check for safety implications.

Deeper is a simulation-based test generator that uses an evolutionary process, i.e., an archive-based NSGA-II augmented with a quality population seed, for generating test cases to test a deep neural network-based lane-keeping system. This paper presents Deeper briefly and summarizes the results of Deeper's participation in the Cyber-physical systems (CPS) testing competition at SBST 2021.

Motivational digital systems offer capabilities to engage and motivate end-users to foster behavioral changes towards a common goal. In general these systems use gamification principles in non-games contexts. Over the years, gamification has gained consensus among researchers and practitioners as a tool to motivate people to perform activities with the ultimate goal of promoting behavioural change, or engaging the users to perform activities that can offer relevant benefits but which can be seen as unrewarding and even tedious. There exists a plethora of heterogeneous application scenarios towards reaching the common good that can benefit from gamification. However, an open problem is how to effectively combine multiple motivational campaigns to maximise the degree of participation without exposing the system to counterproductive behaviours. We conceive motivational digital systems as multi-agent systems: self-adaptation is a feature of the overall system, while individual agents may self-adapt in order to leverage other agents' resources, functionalities and capabilities to perform tasks more efficiently and effectively. Consequently, multiple campaigns can be run and adapted to reach common good. At the same time, agents are grouped into micro-communities in which agents contribute with their own social capital and leverage others' capabilities to balance their weaknesses. In this paper we propose our vision on how the principles at the base of the autonomous and multi-agent systems can be exploited to design multi-challenge motivational systems to engage smart communities towards common goals. We present an initial version of a general framework based on the MAPE-K loop and a set of research challenges that characterise our research roadmap for the implementation of our vision.

This paper presents the platooning research within the Safe Cooperating Cyber-Physical Systems using Wireless Communication (SafeCOP) project. Cooperating Cyber-Physical Systems (CO-CPS) using wireless communication and having multiple stakeholders, dynamic system definitions (openness), and unpredictable operating environments, are the main application of SafeCOP. In addition to safety assurance methods and tools, SafeCOP devises a runtime manager architecture that detects irregular operation, hence, prompting a safe degraded mode in case of need. SafeCOP lays a safety and security umbrella over the usage of current wireless technologies, contributes to new standards and regulations by providing scientifically validated solutions to establish standards which also addresses cooperation and system-of-systems issues. SafeCOP addresses several use cases that solve customer related problems. However, in this paper we will present a use case that extract generic principles from the combination of the previous use cases to stimulate the European collaboration around the project objectives, and to collect general requirements for the SafeCOP solution, applicable across all the areas considered. We consider a CO-CPS composed of two or more systems moving in a platoon while cooperating in a safe function., SafeCOP - Safe Cooperating Cyber-Physical Systems using Wireless Communication

This paper presents the platooning research within the Safe Cooperating Cyber-Physical Systems using Wireless Communication (SafeCOP) project. Cooperating Cyber-Physical Systems (CO-CPS) using wireless communication and having multiple stakeholders, dynamic system definitions (openness), and unpredictable operating environments, are the main application of SafeCOP. In addition to safety assurance methods and tools, SafeCOP devises a runtime manager architecture that detects irregular operation, hence, prompting a safe degraded mode in case of need. SafeCOP lays a safety and security umbrella over the usage of current wireless technologies, contributes to new standards and regulations by providing scientifically validated solutions to establish standards which also addresses cooperation and system-of-systems issues. SafeCOP addresses several use cases that solve customer related problems. However, in this paper we will present a use case that extract generic principles from the combination of the previous use cases to stimulate the European collaboration around the project objectives, and to collect general requirements for the SafeCOP solution, applicable across all the areas considered. We consider a CO-CPS composed of two or more systems moving in a platoon while cooperating in a safe function., SafeCOP - Safe Cooperating Cyber-Physical Systems using Wireless Communication

This paper presents the platooning research within the Safe Cooperating Cyber-Physical Systems using Wireless Communication (SafeCOP) project. Cooperating Cyber-Physical Systems (CO-CPS) using wireless communication and having multiple stakeholders, dynamic system definitions (openness), and unpredictable operating environments, are the main application of SafeCOP. In addition to safety assurance methods and tools, SafeCOP devises a runtime manager architecture that detects irregular operation, hence, prompting a safe degraded mode in case of need. SafeCOP lays a safety and security umbrella over the usage of current wireless technologies, contributes to new standards and regulations by providing scientifically validated solutions to establish standards which also addresses cooperation and system-of-systems issues. SafeCOP addresses several use cases that solve customer related problems. However, in this paper we will present a use case that extract generic principles from the combination of the previous use cases to stimulate the European collaboration around the project objectives, and to collect general requirements for the SafeCOP solution, applicable across all the areas considered. We consider a CO-CPS composed of two or more systems moving in a platoon while cooperating in a safe function., SafeCOP - Safe Cooperating Cyber-Physical Systems using Wireless Communication

This paper presents the platooning research within the Safe Cooperating Cyber-Physical Systems using Wireless Communication (SafeCOP) project. Cooperating Cyber-Physical Systems (CO-CPS) using wireless communication and having multiple stakeholders, dynamic system definitions (openness), and unpredictable operating environments, are the main application of SafeCOP. In addition to safety assurance methods and tools, SafeCOP devises a runtime manager architecture that detects irregular operation, hence, prompting a safe degraded mode in case of need. SafeCOP lays a safety and security umbrella over the usage of current wireless technologies, contributes to new standards and regulations by providing scientifically validated solutions to establish standards which also addresses cooperation and system-of-systems issues. SafeCOP addresses several use cases that solve customer related problems. However, in this paper we will present a use case that extract generic principles from the combination of the previous use cases to stimulate the European collaboration around the project objectives, and to collect general requirements for the SafeCOP solution, applicable across all the areas considered. We consider a CO-CPS composed of two or more systems moving in a platoon while cooperating in a safe function., SafeCOP - Safe Cooperating Cyber-Physical Systems using Wireless Communication

This paper presents the platooning research within the Safe Cooperating Cyber-Physical Systems using Wireless Communication (SafeCOP) project. Cooperating Cyber-Physical Systems (CO-CPS) using wireless communication and having multiple stakeholders, dynamic system definitions (openness), and unpredictable operating environments, are the main application of SafeCOP. In addition to safety assurance methods and tools, SafeCOP devises a runtime manager architecture that detects irregular operation, hence, prompting a safe degraded mode in case of need. SafeCOP lays a safety and security umbrella over the usage of current wireless technologies, contributes to new standards and regulations by providing scientifically validated solutions to establish standards which also addresses cooperation and system-of-systems issues. SafeCOP addresses several use cases that solve customer related problems. However, in this paper we will present a use case that extract generic principles from the combination of the previous use cases to stimulate the European collaboration around the project objectives, and to collect general requirements for the SafeCOP solution, applicable across all the areas considered. We consider a CO-CPS composed of two or more systems moving in a platoon while cooperating in a safe function., SafeCOP - Safe Cooperating Cyber-Physical Systems using Wireless Communication

Providing computer-based services for vehicular systems has evolved to the point where majority of functions are realised by software. However, the need to provide safety in critical functions such as braking and engine control requires an approach that can guarantee reliable operation of the functions. At the same time, there are a variety of vehicle functions that are less critical. The main challenge for the vehicle manufacturers is to provide both types of functions in an economic and reliable manner. To meet this challenge, this paper considers the Rubus tool chain for model-and component-based development of vehicle software and a well-proven (in the industrial use for over twenty years) and certified (according to ISO 26262) real-time operating system for its execution. The paper provides an overview of the Rubus approach and driving concepts as well as the research results that are used in providing its tool chain. Moreover, the paper presents a success story of a unique academic-industrial collaboration in the vehicle domain that has resulted in sustained development of the tool chain. The collaborators form a clear value chain from academia, through tool developer, to the end users of the technology. The paper also highlights the perspectives of the collaborators and discusses the challenges faced, experiences gained and lessons learned from several technology transfer projects.

This paper presents the platooning research within the Safe Cooperating Cyber-Physical Systems using Wireless Communication (SafeCOP) project. Cooperating Cyber-Physical Systems (CO-CPS) using wireless communication and having multiple stakeholders, dynamic system definitions (openness), and unpredictable operating environments, are the main application of SafeCOP. In addition to safety assurance methods and tools, SafeCOP devises a runtime manager architecture that detects irregular operation, hence, prompting a safe degraded mode in case of need. SafeCOP lays a safety and security umbrella over the usage of current wireless technologies, contributes to new standards and regulations by providing scientifically validated solutions to establish standards which also addresses cooperation and system-of-systems issues. SafeCOP addresses several use cases that solve customer related problems. However, in this paper we will present a use case that extract generic principles from the combination of the previous use cases to stimulate the European collaboration around the project objectives, and to collect general requirements for the SafeCOP solution, applicable across all the areas considered. We consider a CO-CPS composed of two or more systems moving in a platoon while cooperating in a safe function., SafeCOP - Safe Cooperating Cyber-Physical Systems using Wireless Communication

In the automotive domain, the employment of agile development is currently hindered by the fact that the safety lifecycle, which implies the creation and maintenance of safety work products, is manually executed, being a complex and expensive process. Given a change in the system under consideration, ISO 26262 recommends that the impact of that change on the safety case of the system shall be assessed and that the safety case shall be correspondingly updated. To this end, in this paper, while assuming a model-based system and safety engineering context, we propose checkable safety case models, which are semantically rich safety case models integrated with system and safety engineering models (i.e., work products of a model-based safety lifecycle). The semantically rich specification and the model integration allow for automated consistency checks between the safety case and the system, specifically its engineering models. We exemplify our contributions via an in-vehicle driver assistance system for driving through intersections.

Recurrent Neural Networks (RNN) are widely used for learning sequences in applications such as EEG classification. Complex RNNs could be hardly deployed on wearable devices due to their computation and memory-intensive processing patterns. Generally, reduction in precision leads much more efficiency and binarized RNNs are introduced as energy-efficient solutions. However, naive binarization methods lead to significant accuracy loss in EEG classification. In this paper, we propose a multi-level binarized LSTM, which significantly reduces computations whereas ensuring an accuracy pretty close to the full precision LSTM. Our method reduces the delay of the 3-bit LSTM cell operation 47× with less than 0.01% accuracy loss.

In the automotive domain, the employment of agile development is currently hindered by the fact that the safety lifecycle, which implies the creation and maintenance of safety work products, is manually executed, being a complex and expensive process. Given a change in the system under consideration, ISO 26262 recommends that the impact of that change on the safety case of the system shall be assessed and that the safety case shall be correspondingly updated. To this end, in this paper, while assuming a model-based system and safety engineering context, we propose checkable safety case models, which are semantically rich safety case models integrated with system and safety engineering models (i.e., work products of a model-based safety lifecycle). The semantically rich specification and the model integration allow for automated consistency checks between the safety case and the system, specifically its engineering models. We exemplify our contributions via an in-vehicle driver assistance system for driving through intersections.

Deep neural networks (DNN) have achieved quality results in various applications of computer vision, especially in image classification problems. DNNs are computational intensive, and nowadays, their acceleration on the FPGA has received much attention. Many methods to accelerate DNNs have been proposed. Despite their performance features like acceptable accuracy or low latency, their use is not widely accepted by software designers who usually do not have enough knowledge of the hardware details of the proposed accelerators. HLS tools are the major promising tools that can act as a bridge between software designers and hardware implementation. However, not only most HLS tools just support C and C++ descriptions as input, but also their result is very sensitive to the coding style. It makes it difficult for the software developers to adopt them, as DNNs are mostly described in high-level languages such as Tensorflow or Keras. In this paper, an integrated toolchain is presented that, in addition to converting the Keras DNN descriptions to a simple, flat, and synthesizable C output, provides other features such as accuracy verification, C level knobs to easily change the data types from floating-point to fixed-point with arbitrary bit width, and latency and area utilization adjustment using HLS knobs.

In the past, assertions were mostly used to validate the system through the design and simulation process. Later, a new method known as assertion synthesis was introduced, which enabled the designers to use the assertions for high-speed hardware emulation and safety and reliability insurance after tape-out. Although the synthesis of the assertions at the register transfer level is proposed and implemented in several works, none of them can be adopted for high-level assertions. In this paper, we propose the SHiLA framework and a detailed implementation guide by which assertion synthesis can also be applied to the high-level design processes. The proposed method, which is fully tool independent, is not only an enabler to highspeed assertion-Assisted simulation but can also be used in other scenarios that need assertion synthesis, as it has the minimum possible effect on the main design's performance.

In this paper, we discuss challenges when using neural networks (NNs) in safety-critical applications. We address the challenges one by one, with aviation safety in mind. We then introduce a possible implementation to overcome the challenges. Only a small portion of the solution has been implemented physically and much work is considered as future work. Our current understanding is that a real implementation in a safety-critical system would be extremely difficult. Firstly, to design the intended function of the NN, and secondly, designing monitors needed to achieve a deterministic and fail-safe behavior of the system. We conclude that only the most valuable implementations of NNs should be considered as meaningful to implement in safety-critical systems.

In this paper, we evaluate different methods for statistical determination of application resource dependency in multi-core systems. We measure the performance counters of an application during run-time and create a system resource usage profile. We then use the resource profile to evaluate the application dependency on the specific resource. We discuss and evaluate two methods to process the data, including moving average filter and partitioning the data into smaller segments in order to interpret data for correlation calculations. Our aim with this study is to evaluate and create a generalizeable methods for automatic determination of resource dependencies. The final outcome of the methods used in this study is the answer to the question: 'To what resources is this application dependent on?'. The recommendation of this tool will be used in conjunction with our last-level cache partitioning controller (LLC-PC), to make decision if an application should receive last-level cache partition slices., DPAC, XPRES

Biometric authentication has seen a widespread increase in popularity as supporting technology has become common in mass produced consumer electronics. Like fingerprints, each individual has unique patterns in the iris, which makes it a common approach for implementing visual biometric authentication. The paper describes a novel system for extracting the iris pattern and using it for identification of people. The system uses Haar wavelet decomposition and 2D Gabor filtering to extract the pattern data. The pattern data is then used with bitwise XOR comparison for final identification matching. Instead of manually selecting parameters for the Gabor filter, a machine learning method called Particle Swarm Optimization was used. The parameters that gave the best matching result were then implemented in the filter design. The implemented system was evaluated on images obtained from 6 individuals in different settings. The evaluation showed that matching identification could be achieved for the database used. The prepossessing of images with Independent Component Analysis was also used to remove the reflections on the images but that did not improve the classification significantly. Still we were able to perfectly distinguish between the individuals. Further preprocessing and a larger training database would be required to get more general and robust results.

Model checking a software system is about verifying that the state trajectory of every execution of the software satisfies formally specified properties. The set of possible executions is modeled as a transition system. Each 'state' in the transition system represents an assignment of values to variables, and a state trajectory (a path through the transition system) is a sequence of such assignments. For cyberphysical systems (CPSs), however, we are more interested in the state of the physical system than the values of the software variables. The value of model checking the software therefore depends on the relationship between the state of the software and the state of the physical system. This relationship can be complex because of the real-time nature of the physical plant, the sensors and actuators, and the software that is almost always concurrent and distributed. In this paper, we study different ways to construct a transition system model for the distributed and concurrent software components of a CPS. We describe a logical-time based transition system model, which is commonly used for verifying programs written in synchronous languages, and derive the conditions under which such a model faithfully reflects physical states. When these conditions are not met (a common situation), a finer-grained event-based transition system model may be required. Even this finer-grained model, however, may not be sufficiently faithful, and the transition system model needs to be refined further to express not only the properties of the software, but also the properties of the hardware on which it runs. We illustrate these tradeoffs using a coordination language called Lingua Franca that is well-suited to extracting transition system models at these various levels of granularity, and we extend the Timed Rebeca language and its tool Afra to perform this extraction and then to perform model checking.

Moving towards new technologies, such as Time Sensitive Networking (TSN), in industries should be gradual with a proper integration process instead of replacing the existing ones to make it beneficial in terms of cost and performance. Within this context, this paper identifies the challenges of integrating a legacy EtherCAT network, as a commonly used technology in the automation domain, into a TSN network. We show that clock synchronization plays an essential role when it comes to EtherCAT-TSN network integration with important requirements. We propose a clock synchronization mechanism based on the TSN standards to obtain a precise synchronization among EtherCAT nodes, resulting to an efficient data transmission. Based on a formal verification framework using UPPAAL tool we show that the integrated EtherCAT-TSN network with the proposed clock synchronization mechanism achieves at least 3 times higher synchronization precision compared to not using any synchronization.

Solving Integer Linear Programming (ILP) models generally lies in the category of NP-hard problems. Therefore, as the size of ILP models grows, the efficiency of exact algorithms for solving the models reduced significantly and for large models it is not possible to have the result. Genetic Algorithm (GA) is a metaheuristic method capable of adjusting and redesigning parameters and operations according to the characteristics of ILP models. Still GA has huge search space for large models and parallelization is a suitable technique to tackle this problem. This paper presents a scalable parallel GA to solve large ILP models derived from behavioral synthesis of digital circuits. We show that although models have non-binary variables, only binary variables are sufficient for coding chromosomes. We also use 'unknown' values for some genes to decrease the likelihood of inconsistency in the encoded constraints. Our experiments verify the efficiency and scalability of the proposed algorithm on multicore platforms. The proposed method outperforms IBM ILOG CPLEX 12.6 and MI-LXPM algorithm where the ILP models include 550 to 2258 int / binary decision variables. Also, the results indicate that the saturation point of using parallel processing elements for solving the large ILP models is at least 60.

Long Short-Term Memory (LSTM) is widely used in various sequential applications. Complex LSTMs could be hardly deployed on wearable and resourced-limited devices due to the huge amount of computations and memory requirements. Binary LSTMs are introduced to cope with this problem, however, they lead to significant accuracy loss in some applications such as EEG classification which is essential to be deployed in wearable devices. In this paper, we propose an efficient multi-level binarized LSTM which has significantly reduced computations whereas ensuring an accuracy pretty close to full precision LSTM. By deploying 5-level binarized weights and inputs, our method reduces area and delay of MAC operation about 31× and 27× in 65nm technology, respectively with less than 0.01% accuracy loss. In contrast to many compute-intensive deep-learning approaches, the proposed algorithm is lightweight, and therefore, brings performance efficiency with accurate LSTM-based EEG classification to realtime wearable devices.

Blockchain is a shared, distributed ledger on which transactions are digitally recorded and linked together. Smart Contracts are programs running on Blockchain and are used to perform transactions in a distributed environment without need for any trusted third party. Since smart contracts are used to transfer assets between contractual parties, their safety and security are crucial and badly written and insecure contracts may result in catastrophe. Actor-based programming is known to solve several problems in building distributed software systems. Moreover, formal verification is a solid technique for developing dependable systems. In this paper, we show how the actor model can be used for modeling, analysis and synthesis of smart contracts. We propose Smart Rebeca as an extension of the actor-based language Rebeca, and use the model checking toolset Afra for verification of smart contracts. We implement a synthesizer to synthesize Solidity programs that run on the Ethereum platform from Smart Rebeca models. We examine the challenges and opportunities of our approach in modeling, formal verification, and synthesis of smart contracts using actors.

It has been shown that in some robotic applications, where the execution times cannot be assumed to be independent and identically distributed, a Markov Chain with discrete emission distributions can be an appropriate model. In this paper we investigate whether execution times can be modeled as a Markov Chain with continuous Gaussian emission distributions. The main advantage of this approach is that the concept of distance is naturally incorporated. We propose a framework based on Hidden Markov Model (HMM) methods that 1) identifies the number of states in the Markov Model from observations and fits the Markov Model to observations, and 2) validates the proposed model with respect to observations. Specifically, we apply a tree-based cross-validation approach to automatically find a suitable number of states in the Markov model. The estimated models are validated against observations, using a data consistency approach based on log likelihood distributions under the proposed model. The framework is evaluated using two test cases executed on a Raspberry Pi Model 3B+ single-board computer running Arch Linux ARM patched with PREEMPT_RT. The first is a simple test program where execution times intentionally vary according to a Markov model, and the second is a video decompression using the ffmpeg program. The results show that in these cases the framework identifies Markov Chains with Gaussian emission distributions that are valid models with respect to the observations.

RESTful APIs are an increasingly common way to expose software systems functionality and it is therefore of high interest to find methods to automatically test and verify such APIs. To lower the barrier for industry adoption, such methods need to be straightforward to use with a low effort. This paper introduces a method to explore the behaviour of a RESTful API. This is done by using automatic property-based tests produced from OpenAPI documents that describe the REST API under test. We describe how this method creates artifacts that can be leveraged both as property-based test generators and as a source of validation for results (i.e., as test oracles). Experimental results, on both industrial and open source services, indicate how this approach is a low effort way of finding real faults. Furthermore, it supports building additional knowledge about the system under test by automatically exposing misalignment of specification and implementation. Since the tests are generated from the OpenAPI document this method automatically evolves test cases as the REST API evolves.

The cloud computing paradigm provides remote computing resources to the cloud service consumers and businesses. When combined with Internet of Things (IoT), both technologies open up a wide range of new possibilities for more agile and flexible applications. However, guaranteed quality of service is essential in provisioning of cloud services, which makes Service Level Agreements (SLAs) a focal point in the cloud computing and IoT ecosystem. The SLA definition and modeling phase is crucial in establishing SLAs between service providers and consumers. This paper identifies that the research on definition and modeling of SLAs for cloud services in IoT is widely dispersed and there is a lack of a systematic and comprehensive literature review. Thus, in this paper we build on top of a previously conducted systematic mapping study on management of SLAs for cloud computing and IoT to perform a comprehensive systematic review and discuss sub-categorization of the definition and modeling aspects of SLAs for cloud services in IoT. Furthermore we analyze the extracted relevant literature, present commonalities in the studies, identify gaps and discuss opportunities for further research in the area.