Formal Specification and Verification of Autonomous Robotic Systems

Abstract

Autonomous robotic systems are complex, hybrid, and often safety-critical; this makes their formal specification and verification uniquely challenging. Though commonly used, testing and simulation alone are insufficient to ensure the correctness of, or provide sufficient evidence for the certification of, autonomous robotics. Formal methods for autonomous robotics has received some attention in the literature, but no resource provides a current overview. This paper systematically surveys the state-of-the-art in formal specification and verification for autonomous robotics. Specially, it identifies and categorises the challenges posed by, the formalisms aimed at, and the formal approaches for the specification and verification of autonomous robotics. Introduction, Methodology and Related WorkAn autonomous system is an artificially intelligent entity that makes decisions in response to input, independent of human interaction. Robotic systems are physical entities that interact with the physical world. Thus, we consider an autonomous robotic system as a machine that uses Artificial Intelligence (AI), has a physical presence in and interacts with the real world. They are complex, inherently hybrid, systems, combining both hardware and software; they often require close safety, legal, and ethical consideration. Autonomous robotics are increasingly being used in commonplace-scenarios, such as driverless cars [68], pilotless aircraft [176], and domestic assistants [174,60].While for many engineered systems, testing, either through real deployment or via simulation, is deemed sufficient; the unique challenges of autonomous robotics, their dependence on sophisticated software control and decision-making, and their increasing deployment in safety-critical scenarios, require a stronger form of verification. This leads us towards using formal methods, which are mathematically-based techniques for the specification and verification of software systems, to ensure the correctness of, and provide sufficient evidence for the certification of, robotic systems.We contribute an overview and analysis of the state-of-the-art in formal specification and verification of autonomous robotics. §1.1 outlines the scope, research questions and search criteria for our survey. §1.2 describes related work concerning formal methods for robotics and differentiates them from our work. We recognise the important role that middleware architectures and, non-and semi-formal techniques have in the development of reliable robotics and we briefly summarise some of these techniques in §2. The specification and verification challenges raised by autonomous robotic systems are discussed next: §3 describes the challenges of their context (the external challenges) and §4 describes the challenges of their organisation (the internal challenges). §5 discusses the formalisms used in the literature for specification and verification of autonomous robotics. §6 characterises the approaches to formal specification and verification of autonomous robotics found in the li...

A Summary of Formal Specification and Verification of Autonomous Robotic Systems

“…This short paper summarises our recently published survey of the formal specification and verification techniques that have been applied to autonomous robotic systems [5], which provides a comprehensive overview and analysis of the stateof-the-art, and identifies promising new research directions and challenges for the formal methods community. Previous work, which draws from this survey, advocates the use of integrated formal methods for autonomous robotic systems [2].…”

“…The corresponding journal paper [5] identifies and investigates the following three research questions: RQ1: What are the challenges when formally specifying and verifying the behaviour of (autonomous) robotic systems? RQ2: What are the current formalisms, tools, and approaches used when addressing the answer to RQ1?…”

“…In addition to answering the research questions, the survey [5] illustrates opportunities for research applying formal methods (and Integrated Formal Methods (iFM)) to robotics and autonomous systems -either by identifying the popular languages that integration could use, or by showing the gaps that could be filled by iFM. It also provides a brief overview of some popular general software engineering techniques for robotic systems including middleware architectures, testing, and simulation approaches, domain specific languages, graphical notations, and model-driven engineering or XML-based approaches.…”

Towards Integrating Formal Verification of Autonomous Robots with Battery Prognostics and Health Management

“…Probabilistic model checking (PMC) [25] has been successfully used to analyse quantitative properties of systems across a variety of application domains, including robotics [28]. This involves the construction of a probabilistic model, commonly using Discrete Time Markov Chain (DTMC), Continuous Time Markov Chain (CTMC) or Markov Decision Process (MDP), that formally represent the behaviour of a system over time.…”

“…model checking and theorem proving, offer a substantial opportunity in this direction [12]. Indeed, formal methods for autonomous robots have received great attention [6,28], both in controller synthesis, see e.g. [12,30], and in verifying safety and reliability when the control policy is given, see e.g.…”