Control Barrier Function Contracts for Vehicular Mission Planning Under Signal Temporal Logic Specifications

TL;DR

This paper introduces a compositional control synthesis framework that leverages assume-guarantee contracts and control barrier functions to ensure safe vehicular mission planning under complex temporal logic specifications.

Contribution

It proposes a novel method combining STL-based mission decomposition with barrier function contracts for safe, correct-by-construction vehicle control.

Findings

Effective in avoiding conservatism of prior methods

Successfully applied to vehicular safety and traffic regulation constraints

Demonstrated on a realistic vehicular mission planning case study

Abstract

We present a compositional control synthesis method based on assume-guarantee contracts with application to correct-by-construction design of vehicular mission plans. In our approach, a mission-level specification expressed in a fragment of signal temporal logic (STL) is decomposed into predicates defined on non-overlapping time intervals. The STL predicates are then mapped to an aggregation of contracts associated with continuously differentiable time-varying control barrier functions. The barrier functions are used to constrain the lower-level control synthesis problem, which is solved via quadratic programming. Our approach can avoid the conservatism of previous methods for task-driven control based on under-approximations. We illustrate its effectiveness on a case study motivated by vehicular mission planning under safety constraints as well as constraints imposed by traffic regulations under vehicle-to-vehicle and vehicle-to-infrastructure communication.