Topic
Collision avoidance
About: Collision avoidance is a research topic. Over the lifetime, 8014 publications have been published within this topic receiving 111414 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: A real-time and distributed algorithm for both collision and deadlock avoidance by repeatedly stopping and resuming robots and is found to be not only practically operative but also maximally permissive.
Abstract: Collision avoidance is a critical problem in motion planning and control of multirobot systems. Moreover, it may induce deadlocks during the procedure to avoid collisions. In this paper, we study the motion control of multirobot systems where each robot has its own predetermined and closed path to execute persistent motion. We propose a real-time and distributed algorithm for both collision and deadlock avoidance by repeatedly stopping and resuming robots. The motion of each robot is first modeled as a labeled transition system, and then controlled by a distributed algorithm to avoid collisions and deadlocks. Each robot can execute the algorithm autonomously and real-timely by checking whether its succeeding state is occupied and whether the one-step move can cause deadlocks. Performance analysis of the proposed algorithm is also conducted. The conclusion is that the algorithm is not only practically operative but also maximally permissive. A set of simulations for a system with four robots are carried out in MATLAB. The results also validate the effectiveness of our algorithm.
53 citations
TL;DR: In this article, the authors considered the problem of close target reconnaissance by a group of autonomous agents and developed a decentralized control scheme for this overall task and the finite-time convergence of the system under the proposed control law is established.
Abstract: This manuscript considers the problem of close target reconnaissance by a group of autonomous agents. The overall close target reconnaissance (CTR) involves subtasks of avoiding inter-agent collisions, reaching a close vicinity of a specific target position, and forming an equilateral polygon formation around the target. The agents performing the task fly at a constant speed to mimic the velocity behavior of small fixed-wing unmanned aerial vehicles (UAV). A decentralized control scheme is developed for this overall task and the finite-time convergence of the system under the proposed control law is established. Furthermore, it is guaranteed that no collision occurs among the agent. The relevant analysis and simulation test results are provided. Copyright © 2010 John Wiley & Sons, Ltd.
53 citations
TL;DR: In this paper, a fuzzy collision avoidance expert system that includes a knowledge base to store facts and rules, an inference engine to simulate experts' decisions and a fuzzy interface device was designed to resolve the problems of collision.
Abstract: Collision avoidance remains the most important concern for ships at sea. Despite the electronic equipment now fitted on ships to support the mariner, expert experience is still essential when a ship is in danger of colliding with the others. To include these experts' experiences to resolve the problems of collision, we have designed a fuzzy collision-avoidance expert system that includes a knowledge base to store facts and rules, an inference engine to simulate experts' decisions and a fuzzy interface device. Either a quartermaster or an autopilot system can then implement the avoidance action proposed in the research. To perform the task of collision-avoidance effectively, a robust autopilot system using the state space H∞ control methodology has been designed to steer a ship safely for various conditions at sea in performing course keeping, course-changing and route-tracking more robustly. The integration of fuzzy collision-avoidance and H∞autopilot systems is then proposed in this paper.
53 citations
05 Dec 2011
TL;DR: A goal-directed 3D reactive obstacle avoidance algorithm specifically designed for Rotorcraft Unmanned Aerial Vehicles (RUAVs) that fly point-to-point type trajectories that detects potential collisions within a cylindrical Safety Volume projected ahead of the UAV.
Abstract: We present a goal-directed 3D reactive obstacle avoidance algorithm specifically designed for Rotorcraft Unmanned Aerial Vehicles (RUAVs) that fly point-to-point type trajectories The algorithm detects potential collisions within a cylindrical Safety Volume projected ahead of the UAV This is done in a 3D occupancy map representation of the environment An expanding elliptical search is performed to find an Escape Point; a waypoint which offers a collision free route past obstacles and towards a goal waypoint An efficient occupied voxel checking technique is employed which approximates the Safety Volume by a series of spheres, and uses an approximate nearest neighbour search in a Bkd-tree representation of the occupied voxels Tests show the algorithm can typically find an Escape Point in under 100 ms using onboard UAV processing for a cluttered environment with 20 000 occupied voxels Successful collision avoidance results are presented from simulation experiments and from flights with an autonomous helicopter equipped with stereo and laser range sensors
53 citations
TL;DR: This paper shows, using a two-step proof, that the avoidance part of the control laws guarantees safety of the agents independently of the coordinating part, and establishes an ultimate bound on the region to which all the agents converge to.
53 citations