Modeling and Testing of PILOT Plans Interpretation Algorithms

PILOT (Programming and Interpreted Language Of actions for Telerobotics) is a graphical and interpreted language dedicated to the r emote control of systems. It is provided with a control system whose various modules have been modeled with the help of f inite state automata. The work described in this paper follows a preceding work which consisted in applying static and dynamic testing techniques to PILOT plans interpreter programs. The goal i s to adopt a more "formal" approach aiming at modeling the interpretation algorithms, at verifying their conformance to the operational semantics of the language, at correcting the possible malfunctions, then to regenerate the interpreter c ode from the validated model. We use colored Petri nets and Design/CPN for the modeling. Design/CPN has been developed in the USA and is currently maintained b y the University of Aarrhus in Denmark (see http://www.daimi.aau.dk/DesignCPN for more information). This paper starts by a brief presentation of the language PILOT and of its control system, with a particular care on the working of the interpreter. An overview of the mod- eling of discrete e vent systems is then g iven in the next section and the c hoice of Petri nets for the modeling of the interpretation algorithms is argued. This s econd sec- tion also situates the current work with respect t o o ther related works. The third section discusses the modeling of the plan as well as the modeling of the interpreter algo- rithms and the simulation of their execution. The paper ends by the testing of the models and the interpretation of the simulation results.