Verified Design of Robotic Autonomous Systems using Probabilistic Model Checking
Atef Azaiez, Alireza David Anisi
TL;DR
This work addresses the absence of formal guarantees in the concept-design phase of Robotic Autonomous Systems by introducing a Probabilistic Model Checking ($PMC$) based framework that integrates Formal Methods with Model-Based Systems Engineering and Multi-Criteria Decision Making. The method constructs a parametric $DTMC$ model of design variants, maps verifiable design criteria into $PCTL$ properties, and uses $PRISM$ to verify each variant, yielding a set of Verified Designs ($VD$) with scores that are then aggregated via MCDM for ranking. A concrete agri-RAS use-case demonstrates the workflow: defining a domain-specific design criteria set, generating 12 design-space variants, filtering via PMC against stated success criteria, and presenting top designs with radar plots to support decision-making. The approach enables robust, verifiable concept selection under uncertainty and points to future automation and extension to broader system lifecycles and to more expressive probabilistic models such as $MDP$.
Abstract
Safety and reliability play a crucial role when designing Robotic Autonomous Systems (RAS). Early consideration of hazards, risks and mitigation actions -- already in the concept study phase -- are important steps in building a solid foundations for the subsequent steps in the system engineering life cycle. The complex nature of RAS, as well as the uncertain and dynamic environments the robots operate within, do not merely effect fault management and operation robustness, but also makes the task of system design concept selection, a hard problem to address. Approaches to tackle the mentioned challenges and their implications on system design, range from ad-hoc concept development and design practices, to systematic, statistical and analytical techniques of Model Based Systems Engineering. In this paper, we propose a methodology to apply a formal method, namely Probabilistic Model Checking (PMC), to enable systematic evaluation and analysis of a given set of system design concepts, ultimately leading to a set of Verified Designs (VD). We illustrate the application of the suggested methodology -- using PRISM as probabilistic model checker -- to a practical RAS concept selection use-case from agriculture robotics. Along the way, we also develop and present a domain-specific Design Evaluation Criteria for agri-RAS.
