Minimum-violation LTL Planning with Conflicting Specifications

TL;DR

This paper introduces an algorithm for generating control strategies for robotic vehicles that maximizes mission satisfaction rewards, even when not all specifications can be simultaneously fulfilled, by prioritizing and minimizing violations.

Contribution

It presents a novel automata-based method for minimum-violation LTL planning that handles conflicting specifications with different priorities.

Findings

Algorithm effectively finds optimal control strategies maximizing total rewards.

Demonstrated success on a case study with conflicting mission requirements.

Provides a systematic approach for handling infeasible high-level specifications.

Abstract

We consider the problem of automatic generation of control strategies for robotic vehicles given a set of high-level mission specifications, such as "Vehicle x must eventually visit a target region and then return to a base," "Regions A and B must be periodically surveyed," or "None of the vehicles can enter an unsafe region." We focus on instances when all of the given specifications cannot be reached simultaneously due to their incompatibility and/or environmental constraints. We aim to find the least-violating control strategy while considering different priorities of satisfying different parts of the mission. Formally, we consider the missions given in the form of linear temporal logic formulas, each of which is assigned a reward that is earned when the formula is satisfied. Leveraging ideas from the automata-based model checking, we propose an algorithm for finding an optimal control strategy that maximizes the sum of rewards earned if this control strategy is applied. We demonstrate the proposed algorithm on an illustrative case study.