Developing Cyber-Physical Systems requires methods and tools to support simulation and verification of hybrid (both continuous and discrete) models. The Acumen modeling and simulation language is an open source testbed for exploring the design space of what rigorous-but-practical next-generation tools can deliver to developers of Cyber-Physical Systems. Like verification tools, a design goal for Acumen is to provide rigorous results. Like simulation tools, it aims to be intuitive, practical, and scalable. However, it is far from evident whether these two goals can be achieved simultaneously.

This paper explains the primary design goals for Acumen, the core challenges that must be addressed in order to achieve these goals, the "agile research method" taken by the project, the steps taken to realize these goals, the key lessons learned, and the emerging language design. © ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2016.

Simulation traditionally computes individual trajectories, which severely limits the assessment of overall system behaviour. To address this fundamental shortcoming, we rely on computing enclosures to determine bounds on system behaviour instead of individual traces. In the present case study, we investigate the enclosures of a generic Automatic Emergency Braking (AEB) system and demonstrate how this creates a direct link between requirement specification and standardized safety criteria as put forward by ISO 26262. The case study strongly supports that a methodology based on enclosures can provide a missing link across the engineering process, from design to compliance testing. This result is highly relevant for ongoing efforts to virtualize testing and create a unified tool-chain for the development of next generation Advanced Driver Assistance Systems. © 2014, FISITA. All rights reserved.

We continue to consider the question of what language features are needed to effectively model cyber-physical systems (CPS). In previous work, we proposed using a core language as a way to study this question, and showed how several basic aspects of CPS can be modeled clearly in a language with a small set of constructs. This paper reports on the result of our analysis of two, more complex, case studies from the domain of rigid body dynamics. The first one, a quadcopter, illustrates that previously proposed core language can support larger, more interesting systems than previously shown. The second one, a serial robot, provides a concrete example of why we should add language support for static partial derivatives, namely that it would significantly improve the way models of rigid body dynamics can be expressed. © 2014 IEEE.

We consider the question of what language features are needed to effectively model cyber-physical systems (CPS). In previous work, we proposed a core language called Acumen as a way to study this question, and showed how several basic aspects of CPS can be modeled clearly in a language with a small set of constructs. This paper reports on the result of our analysis of two more complex case studies from the domain of rigid body dynamics. The first one, a quadcopter, illustrates that Acumen can support larger, more interesting systems than previously shown. The second one, a serial robot, provides a concrete example of why explicit support for static partial derivatives can significantly improve the expressivity of a CPS modeling language.

Analytical and simulation results with pseudo-elastic core wire in stone cutting applications are discussed. System specifications and requirements are defined for the operation of the wire at tensions, speed and general conditions similar to the ones optimized for cutting with standard rope wires with beads of the same diameter. Multi-body dynamic simulation parameters are derived from scale homogenization approach. They are used to run multi-body simulation analysis according to the cutting force requirements. Different simulation schemes and approaches are invented to model the effective cutting forces and system dynamic behavior. Constitutive non-linear pseudo-elastic material model is exploited to be utilized in finite element analysis. The results obtained are further used in finite element analysis in order to study the variation of forces among different sections of pseudo-elastic wire. Finally finite element transient analysis is performed to have an insight into the behavior of the wire under time variant loads. © 2012 Elsevier B.V. All rights reserved.

The paper presents a development case of robotic machine for the dismantling of steel-concrete structures using diamondwire technology. The focus is on the application of the so called soft-wire with core made of superelastic alloy in placeof the steel rope traditionally used. Remote-controlled machinery operating in risky areas must be the simplest possiblefor reliability and to shorten the development time as generally these machines are tailored to the task. In the case ofdismantling of nuclear equipment there are two additional reasons to prefer simple designs: the need to decommission thecutting machinery together with the nuclear wastes and the limit to the use of electronics onboard due to radiation. Withsteel-cored cutting wires an active tensioner is needed to compensate for tension shocks occurring during cutting. This isthe most complex component of the cutting system and it requires a control system with actuation and some electronics.A significant benefit comes from the removal of the active tensioner. The current direction is the use of soft wires inplace of the ones with steel core. The steel rope is replaced by a core wire made of superelastic alloy. The tension ofthe wire is an independent cutting parameter. The selection of the core wire architecture and diameter, the point alongthe stress-strain curve where the wire superelastic alloy is in nominal conditions and the use of stress-strain plafond inthe curve are critical. The paper discusses first the principles of cutting with soft wire. Then the design of the cuttingsystem is addressed and the requirements of robotized cutting machinery is discusses. Different simulation schemes andapproaches are proposed to model cutting forces and system dynamics.In a multibody model with the wire treated asa discontinuous flexible winded along a system of pulleys. The data from the multibody analysis is used in the Finiteelements to characterize the static and dynamic response of Pseudo-elastic wire segment between the two diamond beads.

A new participatory approach that makes use of and improves local end-users knowledge has been used to design a new portable mechatronic system for humanitarian demining applications in Sri Lanka, using power tillers as core module. They are very simple and versatile machines with large scale diffusion in developing countries, where they are commonly used for agriculture and transportation purposes. The system, composed by a tractor unit, a ground processing tool and a vegetation cutting tool is firstly introduced. The paper then focuses on the portable control unit allowing to control the machine from remote distance, in case unexploded ordnance or other fragmentation weapons are known to be present. The module allows forward motion by acting on the clutch, differential and acceleration of the power tiller; steering is controlled by additional brakes, mounted on the driving axle. Two wheels supporting the ground processing tool on the front of the machine are connected to the rear driving ones through tracks. The module can be fit to every kind of power tiller actuated by levers, using differential gear, after only little adjustments. The control is pneumatic and it is powered by the engine of the power tiller itself. The unit, like the others modules, responds to the requirements of safety, low-cost and simpleffectiveness.