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Published June 2017 | public
Journal Article

Safety Barrier Certificates for Collisions-Free Multirobot Systems

Abstract

This paper presents safety barrier certificates that ensure scalable and provably collision-free behaviors in multirobot systems by modifying the nominal controllers to formally satisfy safety constraints. This is achieved by minimizing the difference between the actual and the nominal controllers subject to safety constraints. The resulting computation of the safety controllers is done through a quadratic programming problem that can be solved in real-time and in this paper, we describe a series of problems of increasing complexity. Starting with a centralized formulation, where the safety controller is computed across all agents simultaneously, we show how one can achieve a natural decentralization whereby individual robots only have to remain safe relative to nearby robots. Conservativeness and existence of solutions as well as deadlock-avoidance are then addressed using a mixture of relaxed control barrier functions, hybrid braking controllers, and consistent perturbations. The resulting control strategy is verified experimentally on a collection of wheeled mobile robots whose nominal controllers are explicitly designed to make the robots collide.

Additional Information

© 2017 IEEE. Manuscript received April 5, 2016; revised October 28, 2016; accepted January 11, 2017. This paper was recommended for publication by Associate Editor H. Kress-Gazit and Editor T. Murphey upon evaluation of the reviewers' comments. The work of L. Wang and M. Egerstedt was supported by the U.S. National Science Foundation under Grant 1544332 and the work of A. D. Ames was supported by the U.S. National Science Foundation under Grant 1239055.

Additional details

Created:
August 19, 2023
Modified:
October 24, 2023