Unmanned aerial vehicles (UAVs) are being utilized in a growing variety of military and civil situations. One major issue in situations that require multiple UAVs to share the same air space is collision avoidance. A successful collision avoidance system should allow a UAV to prevent all collisions without greatly impacting flight path efficiency. This study reviews literature centered on colli...

This paper presents the first analytical model to derive the saturation throughput of collision avoidance protocols in multi-hop ad hoc networks with nodes randomly placed according to a two-dimensional Poisson distribution. We show that the sender-initiated collision-avoidance scheme performs much better than the ideal CSMA scheme with a separate channel for acknowledgments. More importantly, ...

One of the most promising applications of cognitive radio networks (CRNs)is the efficient exploitation of TV white spaces (TVWSs) for enhancing the performance of wireless networks. In this paper, we propose a cross-layer design (CLD) of carrier sense multiple access with collision avoidance (CSMA/CA) mechanism at the medium access control (MAC) layer with spectrum sensing (SpSe) at the physica...

This paper presents a feasible 3D collision avoidance approach for fixed-wing unmanned aerial vehicles (UAVs). The proposed strategy aims to achieve the desired relative bearing in the horizontal plane and relative elevation in the vertical plane so that the host aircraft is able to avoid collision with the intruder aircraft in 3D. The host aircraft will follow a desired trajectory in the colli...

Multiple multirotor Micro Aerial Vehicles (MAVs) sharing the same airspace require a reliable and robust collision avoidance technique. In this paper we address the problem of multi-MAV reactive collision avoidance. A model-based controller is employed to achieve simultaneously reference trajectory tracking and collision avoidance. Moreover, we also account for the uncertainty of the state esti...

Research into reactive collision avoidance for unmanned aerial vehicles has been conducted on unmanned terrestrial and mini aerial vehicles utilising active Doppler radar obstacle detection sensors. Flight tests conducted by flying a mini UAV at an obstacle have confirmed that a simple reactive collision avoidance algorithm enables aerial vehicles to autonomously avoid obstacles. This builds up...

Navigation and obstacle avoidance are very important issues for the successful use of an autonomous mobile robot. To allow the robot to move between its current and final configurations without any collision within the surrounding environment, motion planning needs much treatment. Thus to generate collision free path it should have proper motion planning as well as obstacle avoidance scheme. Th...

Many medium-access control (MAC) protocols based on a collision-avoidance handshake between the sender and the receiver have been proposed for wireless networks. To date, however, the analysis of these protocols has assumed non-persistent strategies in sending control packets for collision avoidance. The persistent strategies discussed in the past for CSMA and CSMA/CD provide performance improv...

Recently, ship collision avoidance has become essential due to the emergence of special vessels like chemical tankers and VLCCs (very large crude carriers), etc. The information needed for safe navigation is obtained by combining electrical equipment with real-time visual information. However, misjudgements and human errors are the major cause of ship collisions according to research data. The ...