fret
Towards A Catalogue of Requirement Patterns for Space Robotic Missions
Etumi, Mahdi, Taylor, Hazel M., Farrell, Marie
In the development of safety and mission-critical systems, including autonomous space robotic missions, complex behaviour is captured during the requirements elicitation phase. Requirements are typically expressed using natural language which is ambiguous and not amenable to formal verification methods that can provide robust guarantees of system behaviour. To support the definition of formal requirements, specification patterns provide reusable, logic-based templates. A suite of robotic specification patterns, along with their formalisation in NASA's Formal Requirements Elicitation Tool (FRET) already exists. These pre-existing requirement patterns are domain agnostic and, in this paper we explore their applicability for space missions. To achieve this we carried out a literature review of existing space missions and formalised their requirements using FRET, contributing a corpus of space mission requirements. We categorised these requirements using pre-existing specification patterns which demonstrated their applicability in space missions. However, not all of the requirements that we formalised corresponded to an existing pattern so we have contributed 5 new requirement specification patterns as well as several variants of the existing and new patterns. We also conducted an expert evaluation of the new patterns, highlighting their benefits and limitations.
Gecko: Versatile Text Embeddings Distilled from Large Language Models
Lee, Jinhyuk, Dai, Zhuyun, Ren, Xiaoqi, Chen, Blair, Cer, Daniel, Cole, Jeremy R., Hui, Kai, Boratko, Michael, Kapadia, Rajvi, Ding, Wen, Luan, Yi, Duddu, Sai Meher Karthik, Abrego, Gustavo Hernandez, Shi, Weiqiang, Gupta, Nithi, Kusupati, Aditya, Jain, Prateek, Jonnalagadda, Siddhartha Reddy, Chang, Ming-Wei, Naim, Iftekhar
Text embedding models represent natural language as dense vectors, positioning semantically similar text near each other within the embedding space (Gao et al., 2021; Le and Mikolov, 2014; Reimers and Gurevych, 2019). These embeddings are commonly used for a wide range of downstream tasks including document retrieval, sentence similarity, classification, and clustering (Muennighoff et al., 2023). Instead of building separate embedding models for each downstream task, recent efforts seek to create a single embedding model supporting many tasks. The recent development of general-purpose text embedding models presents a challenge: these models require large amounts of training data to comprehensively cover desired domains and skills. Recent embedding efforts have focused on using extensive collections of training examples (Li et al., 2023; Wang et al., 2022).
Monitoring ROS2: from Requirements to Autonomous Robots
Perez, Ivan, Mavridou, Anastasia, Pressburger, Tom, Will, Alexander, Martin, Patrick J.
Runtime verification (RV) has the potential to enable the safe operation of safety-critical systems that are too complex to formally verify, such as Robot Operating System 2 (ROS2) applications. Writing correct monitors can itself be complex, and errors in the monitoring subsystem threaten the mission as a whole. This paper provides an overview of a formal approach to generating runtime monitors for autonomous robots from requirements written in a structured natural language. Our approach integrates the Formal Requirement Elicitation Tool (FRET) with Copilot, a runtime verification framework, through the Ogma integration tool. FRET is used to specify requirements with unambiguous semantics, which are then automatically translated into temporal logic formulae. Ogma generates monitor specifications from the FRET output, which are compiled into hard-real time C99. To facilitate integration of the monitors in ROS2, we have extended Ogma to generate ROS2 packages defining monitoring nodes, which run the monitors when new data becomes available, and publish the results of any violations. The goal of our approach is to treat the generated ROS2 packages as black boxes and integrate them into larger ROS2 systems with minimal effort.
Cloud-based AI: The game-changer not to fret about
The White House is hosting a conference on the future of artificial intelligence. Executives from 38 companies, including Intel, Oracle, Ford, Boeing, Mastercard, Microsoft, and Accenture, will attend the daylong summit. Why is it happening now? AI is poised to create 2.3 million jobs by 2020, while eliminating another 1.8 million jobs, according to Gartner. Topics of discussion are said to include how industries like health care and transportation can best use AI, as well as how to fund research in the field.
Are the robots about to take all the jobs? Don't hold your breath
The claim that nearly half of all US jobs are at risk of being automated has been repeated many times. But is it that straightforward? Gavin Kelly offers some facts that moderate the claim. He concludes that although the impact of evolving technology on jobs is currently impossible to predict, there are other, very real issues we should fret about: decreasing productivity levels, stagnant wages, and poor skills. We are said to live in an increasingly'post-fact' world but it remains the case that an eye-catching statistic can gain its own momentum and shape public debate regardless of its providence or even its author's original intent. So it is on the question of the rise of the robots and the future of work.
Heuristic Search for Generalized Stochastic Shortest Path MDPs
Kolobov, Andrey (University of Washington, Seattle) | Mausam, Mausam (University of Washington, Seattle) | Weld, Daniel S. (University of Washington, Seattle) | Geffner, Hector (ICREA and Universitat Pompeu Fabra)
Research in efficient methods for solving infinite-horizon MDPs has so far concentrated primarily on discounted MDPs and the more general stochastic shortest path problems (SSPs). These are MDPs with 1) an optimal value function V* that is the unique solution of Bellman equation and 2) optimal policies that are the greedy policies w.r.t. V*. This paper’s main contribution is the description of a new class of MDPs, that have well-defined optimal solutions that do not comply with either 1 or 2 above. We call our new class Generalized Stochastic Shortest Path (GSSP) problems. GSSP allows more general reward structure than SSP and subsumes several established MDP types including SSP, positive-bounded, negative, and discounted-reward models. While existing efficient heuristic search algorithms like LAO* and LRTDP are not guaranteed to converge to the optimal value function for GSSPs, we present a new heuristic-search-based family of algorithms, FRET (Find, Revise, Eliminate Traps). A preliminary empirical evaluation shows that FRET solves GSSPs much more efficiently than Value Iteration.