Piotr Matyasik

Alvis – Modelling Language for Concurrent Systems

The chapter presents a description of a novel modelling language called Alvis defined for the design of concurrent especially real-time systems. Alvis combines the advantages of formal methods and practical modelling languages. Based on CCS and XCCS process algebras, Alvis utilizes flexible graphical modelling of interconnections among agents and a high level programming language used for the description of agents behaviour. Each agent in a model can use rule-based systems to support its decisions. A small set of language statements and graphical concepts make Alvis easy to learn and use. The possibility of a formal model verification, makes Alvis a formal modelling language. Alvis modelling environment creates in parallel a model of the considered system and a labelled transition system (LTS graph) that is its formal representation. The LTS graph can be formally verified with the CADP toolbox. A survey of main Alvis features from practical point of view, is given in the chapter.

Formal Description of Alvis Language with α0 System Layer

The paper presents a formal description of a subset of the Alvis language designed for the modelling and formal verification of concurrent systems. Alvis combines possibilities of a formal models verification with flexibility and simplicity of practical programming languages. Alvis provides a graphical modelling of interconnections among agents and a high level programming language used for the description of agents behaviour. Its semantic depends on the so-called system layer. The most universal system layer α0, described in the paper, makes Alvis similar to other formal languages like Petri nets, process algebras, time automata, etc.

Formal Modelling and Verification of Concurrent Systems with XCCS

XCCS is a graphical extension of CCS process algebra. To make CCS more convenient from the software engineering point of view the CCS calculus has been equipped with a graphical modelling language and some operators have been moved to the graphical layer. The proposed approach is supported by a computer tool called the Inez XCCS Editor. Among other things the tool provides a graphical editor for designing XCCS diagrams and a transformation algorithm for exporting XCCS models into CCS scripts. The paper presents both a survey of main features of the XCCS language and a description of the Inez XCCS Editor.

Prolog-Based Real-Time Intelligent Control of the Hexor Mobile Robot

The paper presents a concept of an intelligent control platform for the Hexor mobile robot, based on the XTT knowledge representation method for rule-based systems. The control systems is implemented in Prolog, with use of the Embedded Prolog Platform. The paper presents real-time control capabilities provided by this solution.

Modeling indoor lighting inspection robot behavior using Concurrent Communicating Lists

Today, energy efficiency is one of the top priorities in building design and construction. A significant share of energy usage is due to indoor lighting. Although methods exist for design and control of intelligent lighting systems, the task of real-world lighting assessment and verification remains only partly addressed. This paper describes foundations for design of a robot to conduct regular and automated audits of lighting quality in office buildings, with emphasis on the modeling of its behavior. The proposed model uses the Concurrent Communicating Lists (CCL) notation, which allows it to be easily simulated, executed, and formally verified. The CCL behavior model is discussed in the context of Knowledge-Behavior-Platform (KBP) robotic architecture proposed as a practical model runtime environment.

RobustHX - the robust middleware library for hexor robots

This paper presents RobustHX - an extension of the Robust middleware library, which allows the six-legged Hexor robot to be programmed in Java. Like Lego Mindstorms NXT robots, Hexor has been adopted by many academic centers in Poland as a tool for teaching AI robotics. For this reason, the authors hope that RobustHX may also be found as an interesting teaching aid allowing basic robotic experiments to be carried out.

Alvis Virtual Machine

Alvis is a formal modelling language. It combines graphical modelling of communication schema and a high level programming language to describe behaviour of individual system entities. An Alvis model can be verified formally by using methods based on a system state space. The paper presents the design and the command list of the Alvis Virtual Machine. The aim of the project is to provide an execution environment for Alvis language. Moreover, one of the goals is to allow different hardware units to run Alvis models. Thus, a virtual machine was chosen as a solution.

Knowledge-Based Control of Reactive Systems with Multi-Layer Architecture

This paper presents a concept of an integrated development platform for fast and error-free implementation of embedded intelligent systems. The main idea reside in dividing the control program into separate logic layers. The lowest-level layer uses embedded real-time operating system. The high-level control is knowledge-based and provides an intelligent system behavior. The paper presents some implementation details of the low-level layer and the concept of the intelligent control layer. The concept is then applied to the Hexorll mobile robot platform.

Simulation of Multi-agent Systems with Alvis Toolkit

The paper presents a method of using the Alvis formal modelling language and related software to model and simulate multi-agent systems. The approach has been illustrated with an example of a railway traffic management system for a real train station. One of the main advantages of this approach is the possibility of including artificial intelligence (AI) systems encoded in Haskell into Alvis models. Moreover, Alvis models can be developed at the level very close to the final implementation of the corresponding real system. Thus simulation logs can be treated as a virtual prototype logs.

Communication between agents in Alvis language

Concurrent systems are composed of a set of subsystems (processes, threads etc.) that must communicate between themselves to meet the system requirements. Modelling and programming languages provide different communication modes to handle synchronous and/or asynchronous communication between subsystems. The paper provides a survey of communication modes introduced to the Alvis modelling language and discusses how the communication modes may be used while modelling embedded systems.