ZiZo: Modeling, Simulation and Verification of Reconfigurable Real-time Control Tasks Sharing Adaptive Resources - Application to the Medical Project BROS

Abstract

This research paper deals with the modeling, simulation and model checking of reconfigurable discreteevent control systems to be distributed on networked devices. A system is composed of software tasks with shared resources to control physical processes. A reconfiguration scenario is assumed to be a run-time automatic operation that modifies the system's structure by adding or removing tasks or resources according to user requirements in order to adapt the whole architecture to its environment. Nevertheless, a reconfiguration can bring the system to a blocking problem that is sometimes unsafe, or violates real-time properties. We define new Petri Nets-based modeling solutions for both tasks and resources to meet these constraints. These solutions are applied to a real case study named Browser-based Reconfigurable Orthopedic Surgery (abbrev. BROS) to illustrate the paper's contribution. A new Petri Nets-based editor and random-simulator named ZiZo is developed to model and simulate the BROS reconfigurable architecture. It is based also on the model checker SESA to apply an exhaustive CTL-based formal verification of this architecture to ensure safe reconfiguration scenarios of tasks and resources.

BROMETH: Methodology to design safe reconfigurable medical robotic systems

“…As previously mentioned in the first section, the authors use the patterns proposed in to model how PCP is used in BROS to solve the issue of concurrent access to shared resources. Salem et al used this work and proved its relevance by model‐checking. As an application inspired from BROS, we choose the situation when the surgeon, B‐BROS1 and B‐BROS2 (three tasks) concurrently access the patient arm and BW (two resources).…”

“…Thus, it can automatically perform the whole surgery or bequeath some tasks to the surgeon. The authors in proved that applying a reconfiguration scenario on BROS by switching from one operating mode to another may actually lead to deadlock. This is due to concurrent access to shared resources and is usually unsafe.…”

“…The latter contribution has been proved to be correct thanks to model‐checking, however, we cannot be sure of its relevance when applied on complex real reconfigurable systems. Thus, the authors in proposed a new editor, simulator and model‐checker for R‐TNCES named ZiZo which allows modeling complex reconfigurable real‐time systems using R‐TNCES, like BROS, and simulating the models to check the safeness of the involved system. To be even more sure about the safeness of our medical robotized platform BROS, we propose to use, to the extent possible, simulation software provided by the manufacturers of the robotized components used to visualize the real behavior of the robotized platform once built and, thus, prove its safeness …”

“…We model them using R‐TNCES enriched by PCP to manage the resource sharing. Since R‐TNCES lacks an environment to edit, simulate and verify its models, we develop the new tool ZiZo, an R‐TNCES editor and simulator . Once sure of its safeness, we implement BROS using ABB's simulation environment, RobotStudio .…”

Towards a Secure RA2DL Based Approach

“…Security is an aspect that is often neglected in the design of adaptive systems. However, the use of these systems for critical applications such as controlling power plants, vehicular systems control, and medical devices [19] makes security considerations even more important. Also because of the operational environment of adaptive systems and the reconfiguration actions applied by an RA2DL component.…”