Distributed control of multiple non-holonomic robots with sector vision and range-only measurements for target capturing with collision avoidance

Abstract

Link to this article: http://journals.cambridge.org/abstract_S0263574714000320How to cite this article: A. Zakhar'eva, A. S. Matveev, M. C. Hoy and A. V. Savkin (2015). Distributed control of multiple non-holonomic robots with sector vision and range-only measurements for target capturing with collision avoidance. Robotica, 33, pp 385-412 SUMMARYWe consider a team of autonomous kinematically controlled non-holonomic planar Dubins car-like vehicles. The team objective is to encircle a given target so that all vehicles achieve a common and pre-specified distance from it and are uniformly distributed over the respective circle, and the entire formation rotates around the target with a prescribed angular velocity. The robots do not communicate with each other and any central decision-maker. The sensing capacity of any vehicle is heavily restricted: It has access only to the distance to the target and to the distances to the companion vehicles that are in a given disc sector centered at the vehicle at hand; no robot can distinguish between its companions, and does not know their parameters. A distributed control law is proposed, and mathematically rigorous proofs of its non-local convergence as well as collision avoidance property are presented. The performance of the control law is illustrated by computer simulations and experiments with real robots.

Circumnavigation of a speedy unpredictable target by a group of speed‐ and acceleration‐limited robots

“…Their practical effectiveness has been widely reported. Examples are given by, eg, the results of the experiments with real robots presented in the works, 35,42,[50][51][52][53] where control laws that are similar in some respects to the law proposed in this paper are considered.…”

“…For target capturing problems, the issue of collision avoidance is addressed in the works 18,27,34,35 to the best of the authors knowledge. In the work of El Kamel et al, 18 the problem is to drive fully actuated unicycles with all-to-all communication capability to a prespecified distance from a steady target while avoiding intervehicle collisions.…”

“…However, the angular speed of their rotation around the target is not prespecified and collision avoidance is guaranteed only if, initially, the robots lie on distinct rays rooted at the beacon. In the work of Zakhar'eva et al, 35 nonidentical and unlabeled unicycle-like planar fully-actuated robots with a limited both control range and sector vision of one another and access to only the distance information about a steady target are considered. The proposed control strategy drives them at a prespecified distance to the target and ensures their even self-distribution over the respective circle, along with given angular speed of rotation about the target.…”

“…With an exception of the works, 27,34,35 where only steady targets are treated, a common feature of the aforementioned research is ignorance of bounds on the control input. The latter means that the robots are assumed to enjoy an a priory unspecified and potentially unlimited superiority in maneuverability over the target.…”

“…The latter means that the robots are assumed to enjoy an a priory unspecified and potentially unlimited superiority in maneuverability over the target. Another common trait is ignorance of the collision avoidance issue, with an exception of the work of Zakhar'eva et al, 35 where only a steady target is considered, and the work of Franchi et al, 31 where labeled robots with unlimited "visibility" range and preassigned and maintained ring-like order are treated. Meanwhile, among the survey of papers on target capturing navigation, the authors failed to come across one that tackles the issues of a bounded control input, anonymity of robots to one another, limited sensing range, and collision avoidance in the case of a moving target, in which case, most relevant papers also assume either access to the velocity vector of the target 14,15,17,19,21,31 or a certain level of predictability in its behavior.…”