Multirobot Rendezvous With Visibility Sensors in Nonconvex Environments

Abstract

Abstract-This paper presents a coordination algorithm for mobile autonomous robots. Relying upon distributed sensing the robots achieve rendezvous, that is, they move to a common location. Each robot is a point mass moving in a nonconvex environment according to an omnidirectional kinematic model. Each robot is equipped with line-of-sight limited-range sensors, i.e., a robot can measure the relative position of any object (robots or environment boundary) if and only if the object is within a given distance and there are no obstacles in-between. The algorithm is designed using the notions of robust visibility, connectivity-preserving constraint sets, and proximity graphs. Simulations illustrate the theoretical results on the correctness of the proposed algorithm, and its performance in asynchronous setups and with sensor measurement and control errors.

Computing by Mobile Robotic Sensors

“…There have been several investigations on the gathering problem with sensors operating in the fully synchronous scenario, i.e., in model Sync [39,59,64,91]. The starting point of these investigations is the convergence protocol of Ando et al [2], described in Section 5.2, operating in the Ssync and thus in the Sync models.…”

“…The case when the sensors operate in a non-convex region (see Figure 13), of which they have no map, has been considered only by Ganguli, Cortés, and Bullo in [39]. In such a space, two sensors s and s ′ are said to be mutually visible at time t if not only their distance is at most v but also the segment connecting their positions at time t is completely contained in U;.…”

“…s ′ s Fig. 13 An example of non-convex environment for the gathering problem in [39]. The edges between sensors represent the edges of the visibility graph.…”

Probabilistic Network Formation through Coverage and Freeze-Tag

“…Deterministic and randomized multi-robot rendezvous strategies were proposed in [13]. More recently, results on rendezvous in simplyconnected polygons have been obtained [8]. In [9], the authors provide upper and lower bounds on the time complexity of two geometric laws that result in rendezvous.…”

Graph-theoretic connectivity control of mobile robot networks

“…Indicative of this work is recent literature on connectivity preserving rendezvous [36], [52], [56], [62], [63], flocking [55], [64], and formation control [56], [59], where so far connectivity had been an assumption. Further extensions and contributions involve connectivity control for double integrator agents [49], agents with bounded inputs [65]- [67] and indoor navigation [61], as well as for communication based on radio signal strength [68]- [71] and visibility constraints [36], [62], [72]- [74]. Periodic connectivity for robot teams that need to occasionally split in order to achieve individual objectives [75] and sufficient conditions for connectivity in leader-follower networks [76], also add to the list.…”