Menouer Boubekeur

Process Algebraic Approach to SystemVerilog

We develop a process algebraic framework, called process algebraic framework for IEEE 1800trade SystemVerilog (PAFSV), for formal specification and analysis of IEEE 1800trade SystemVerilog designs. The formal semantics of PAFSV is defined by means of deduction rules that associate a labelled transition system with a PAFSV process. A set of properties of PAFSV is presented for a notion of bisimilarity. PAFSV may be regarded as the formal language of a significant subset of IEEE 1800trade SystemVerilog. This paper serves as an introduction of PAFSV to architects, engineers and researchers from the electronic design community.

Intelligent Hybrid Control Model for Lighting Systems Using Constraint-Based Optimisation

Lighting systems consume a considerable proportion of total energy budgets, particularly for retail and public-office applications, and hence their optimisation can save considerable amounts of energy. This paper proposes an intelligent control strategy to operate the office luminance in order to enhance user comfort and reduce energy consumption. The strategy is applied to an open office scenario, where the controller and the environments are modelled using a hybrid/multi-agent platform. The developed controller uses a constraint-based optimisation technique to compute the optimal settings.We describe the different modelling steps, including the optimisation technique, and outline the simulation results and potential energy benefits of the proposed controller.

Cyber-physical-security framework for building energy management system

Energy management systems (EMS) are used to control energy usage in buildings and campuses, by employing technologies such as supervisory control and data acquisition (SCADA) and building management systems (BMS), in order to provide reliable energy supply and maximise user comfort while minimising energy usage. Historically, EMS systems were installed when potential security threats were only physical. Nowadays, EMS systems are connected to the building network and as a result directly to the outside world. This extends the attack surface to potential sophisticated cyber-attacks, which adversely impact EMS operation, resulting in service interruption and downstream financial implications. Currently, the security systems that detect attacks operate independently to those which deploy resiliency policies and use very basic methods. We propose a novel EMS cyber-physical-security framework that executes a resilient policy whenever an attack is detected using security analytics. In this framework, both the resilient policy and the security analytics are driven by EMS data, where the physical correlations between the data-points are identified to detect outliers and then the control loop is closed using an estimated value in place of the outlier. The framework has been tested using a reduced order model of a real EMS site.

Compositional model-driven design of embedded code for energy-efficient buildings

In embedded software development, model-driven design is well recognized. In this article we describe a compositional model-driven approach for auto-generating embedded code for improving the energy efficiency of building automation applications. We show how we can use a component-based hybrid-systems modelling framework to generate models for simulation and verification. Then, we auto-generate embeddable code from these models. We empirically demonstrate this approach using the hybrid-systems tool Charon, for the domain of energy-efficient lighting control for smart buildings. The paper provides a detailed description of the code generation steps and outlines some results obtained through a simple lighting example.

SC2SCFL: Automated SystemC to

SystemCFL is the formalisation of a reasonable subset of SystemC based on classical process algebras. During the last few years, SystemCFL has been successfully used to give formal specifications of SystemC designs. For formal analysis purposes, so far, users have been required to transform manually their SystemC codes into corresponding SystemCFL specifications. To verify some desired properties of SystemCFL specifications using existing formal verification tools (e.g. NuSMV and SPIN), similarly, manual translations have been needed for turning SystemCFL specifications into corresponding terms of the input language (e.g. SMV and PROMELA) of the selected formal verification tool. Since manual transformation and translations between SystemC codes, SystemCFL specifications, and various formalisms are quite laborious and therefore error-prone, these translations have to be made as much automatic as possible. The first step of the research in these directions is to automate the transformation from SystemC codes to SystemCFL specifications. In this paper, we present SC2SCFL (an automatic translation tool), which converts SystemC codes into corresponding SystemCFL specifications.

SystemC^{\mathbb{FL}}

We propose a methodology for overcoming the current approach of writing diagnostics code for industrial automation applications after the system is designed, which results in significant extra effort/cost, and potential discrepancies between design and diagnostics output. We show how we can automatically generate diagnostics from a more complex simulation model. We show how a model-transformation framework can transform a hybrid-systems simulation model into a propositional-logic diagnostics model with appropriate transformation rules. We illustrate our approach with an example from the domain of control for building lighting systems.

Translation

Currently wireless based control systems lack appropriate development methodologies and tools. The control model and its underlying wireless network are typically developed separately, which can lead to unstable and suboptimal implementations. In this paper we introduce a hybrid-based design methodology that considers the performance parameters of the Wireless Sensor and Actuator Network (WSAN) in order to develop an optimized control system tailored to the specific application environment and sensor network conditions. We first identify the boundaries of the control parameters that maintain stable and optimal control model. Within these boundaries,we determine the optimal WSAN Quality of Service (QoS) parameters through a tuning process in order to reach to optimal Control/WSAN design as illustrated in the case study. The methodology has been illustrated through a distributed lighting control developed using our hybrid/multi-agent platform.

Model-driven diagnostics generation for industrial automation

In order to develop an integrated system that can optimise building operations, all facets of monitoring, control and reconfiguration need to be integrated. To achieve this, we need to develop an integrated system model, together with associated sub-system interfaces. This links the low-level wireless/wired systems monitoring with multi-level control, building information management and user-preference inputs. In this paper we describe an integrated simulation platform that partially fulfils such objectives. We detail through a case study an integrated simulation platform allowing testing, refinement and optimization of the design at an early stage. The paper provides a detailed simulation results and outlines the future works.

WSAN QoS Driven Control Model for Building Operations

Most existing industrial control systems (ICSs), such as building energy management systems (EMSs), were installed when potential security threats were only physical. With advances in connectivity, ICSs are now, typically, connected to communications networks and, as a result, can be accessed remotely. This extends the attack surface to include the potential for sophisticated cyber attacks, which can adversely impact ICS operation, resulting in service interruption, equipment damage, safety concerns, and associated financial implications. In this work, a novel cyber–physical security framework for ICSs is proposed, which incorporates an analytics tool for attack detection and executes a reliable estimation-based attack-resilient control policy, whenever an attack is detected. The proposed framework is adaptable to already implemented ICS and the stability and optimal performance of the controlled system under attack has been proved. The performance of the proposed framework is evaluated using a reduced order model of a real EMS site and simulated attacks.

Integrated Simulation Platform for Optimized Building Operations

We describe a validation approach for Simulink models of industrial cyber-physical systems (CPS), based on an adaptation of a coverage-guided test generation method for hybrid systems. Modelling an industrial CPS requires integrating heterogeneous components, which introduces high complexity in model verification. Using Simulink, which has become a de-facto industrial tool, heterogeneity comes from combining different formalisms (Simulink blocks, Stateflow diagrams, Matlab and C functions, etc.) and mixing different types of dynamics (discrete, continuous). Since the interactions between such components are often too complex to be faithfully captured in an existing mathematical modelling paradigm, we resort to treating them as black box systems while trying to exploit as much as possible a-priori knowledge about them. We first describe our approach: extracting from a Simulink model the information to define the main ingredients of the test generation framework, in particular environment inputs in which faults could be injected and critical states that require good coverage. We then illustrate the approach with an industrial model of an HVAC (Heating, Ventilation and Air Conditioning) system.