A laser-based multi-robot collision avoidance approach in unknown environments

As a fundamental problem, collision avoidance for multiple robots still need further investigation, especially for many robots aggregating in a tight space. In this article, a laser-based collision avoidance approach is proposed in complex multi-robot environments. The laser data is analyzed and processed in terms of distance thresholding, safe passageway analysis, obstacles repulsion, goal position attraction, and inter-robot safety. Specifically, the safe passageway analysis is used to remove unsafe directions effectively, and inter-robot safety processing reduces the possibility of being selected for the directions affected by the neighboring robots. On this basis, an optimized decision is made to guarantee that the robots achieve collision-free motions even in crowded environments. The validity of the proposed approach is verified by simulations.

Download Full-text

Edge-weighted consensus-based formation control strategy with collision avoidance

Robotica ◽

10.1017/s0263574714000368 ◽

2014 ◽

Vol 33 (2) ◽

pp. 332-347 ◽

Cited By ~ 32

Author(s):

Riccardo Falconi ◽

Lorenzo Sabattini ◽

Cristian Secchi ◽

Cesare Fantuzzi ◽

Claudio Melchiorri

Keyword(s):

Mobile Robots ◽

Collision Avoidance ◽

Obstacle Avoidance ◽

Control Strategy ◽

Formation Control ◽

Weighted Graphs ◽

Wheeled Robots ◽

Unknown Environments ◽

Multi Robot

SUMMARYIn this paper, a consensus-based control strategy is presented to gather formation for a group of differential-wheeled robots. The formation shape and the avoidance of collisions between robots are obtained by exploiting the properties of weighted graphs. Since mobile robots are supposed to move in unknown environments, the presented approach to multi-robot coordination has been extended in order to include obstacle avoidance. The effectiveness of the proposed control strategy has been demonstrated by means of analytical proofs. Moreover, results of simulations and experiments on real robots are provided for validation purposes.

Download Full-text

Variable formation control of multiple robots via VRc and formation switching to accommodate large heading changes by leader robot

Advances in Mechanical Engineering ◽

10.1177/1687814019857339 ◽

2019 ◽

Vol 11 (6) ◽

pp. 168781401985733

Author(s):

Sung-Gil Wee ◽

Yanyan Dai ◽

Tae Hun Kang ◽

Suk-Gyu Lee

Keyword(s):

Real Time ◽

Collision Avoidance ◽

Formation Control ◽

Experimental Results ◽

Optimal Size ◽

Multiple Robots ◽

Flexible Control ◽

Formation Pattern ◽

Multi Robot

This article describes a novel multi-robot formation control based on a switching technique that allows follower robots to maintain formation when the leader robot’s direction changes rapidly or unexpectedly. The formation pattern is determined using Virtual Robot’s Center of the multi-robot formation. To avoid collision, the formation of robots reformed in optimal size by estimating the distance between the robot and an obstacle in real time. When the leader robot suddenly changes its direction, waypoints of follower robots are switched and the formation is quickly reconstructed. This prevents follower robots from colliding with each other and reduces their radius of movement and allows them to follow the leader robot at higher speed. The proposed method which is inherently a flexible control of multi-robot formation guarantees collision avoidance and prevents sudden changes in waypoints of the system by gradually changing its size. The validity of the proposed method is demonstrated via simulation and experimental results.

Download Full-text