Recent Approaches and Algorithms to Solutions of the Problems of Collision Avoidance of Unmanned Aerial Vehicles (original) (raw)

Unmanned Aerial Vehicles (UAVs): Collision Avoidance Systems and Approaches

IEEE Access

Moving towards autonomy, unmanned vehicles rely heavily on state-of-the-art collision avoidance systems (CAS). A lot of work is being done to make the CAS as safe and reliable as possible, necessitating a comparative study of the recent work in this important area. The paper provides a comprehensive review of collision avoidance strategies used for unmanned vehicles, with the main emphasis on unmanned aerial vehicles (UAV). It is an in-depth survey of different collision avoidance techniques that are categorically explained along with a comparative analysis of the considered approaches w.r.t. different scenarios and technical aspects. This also includes a discussion on the use of different types of sensors for collision avoidance in the context of UAVs. INDEX TERMS Autonomous aerial vehicles, autonomous vehicles, collision avoidance, active and passive sensors, optimisation-based, force-field based, sense and avoid, geometry based.

A survey of collision avoidance approaches for unmanned aerial vehicles

2009

The ability to integrate unmanned and manned aircraft into airspace is a critical capability that will enable growth in wide varieties of applications. Collision avoidance is a key enabler for the integration of manned and unmanned missions in civil and military operation theaters. Large efforts have been done to address collision avoidance problem to both manned and unmanned aircraft. However, there has been little comparative discussion of the proposed approaches. This paper presents a survey of the collision avoidance approaches those deployed for aircraft, especially for unmanned aerial vehicles. The collision avoidance concept is introduced together with proposing generic functions carried by collision avoidance systems. The design factors of the sense and avoid system, which are used to categorize methods, are explained deeply. Based on the design factors, several typical approaches are categorized.

Evolving Philosophies on Autonomous Obstacle/Collision Avoidance of Unmanned Aerial Vehicles

2011

Much of the benefits of deploying unmanned aerial vehicles can be derived from autonomous missions. For such missions, however, sense-and-avoid capability (i.e., the ability to detect potential collisions and avoid them) is a critical requirement. Collision avoidance can be broadly classified into global and local path-planning algorithms, both of which need to be addressed in a successful mission. Whereas global path planning (which is mainly done offline) broadly lays out a path that reaches the goal point, local collision-avoidance algorithms, which are usually fast, reactive, and carried out online, ensure safety of the vehicle from unexpected and unforeseen obstacles/collisions. Even though many techniques for both global and local collision avoidance have been proposed in the recent literature, there is a great interest around the globe to solve this important problem comprehensively and efficiently and such techniques are still evolving. This paper presents a brief overview of a few promising and evolving ideas on collision avoidance for unmanned aerial vehicles, with a preferential bias toward local collision avoidance.

Evolving Philosophies on Autonomous Obstacle/Collision Avoidance of UAVs

2011

Abstract: Much of the benefits of deploying unmanned aerial vehicles can be derived from autonomous missions. For such missions, however, sense-and-avoid capability (i.e., the ability to detect potential collisions and avoid them) is a critical requirement. Collision avoidance can be broadly classified into global and local path-planning algorithms, both of which need to be addressed in a successful mission. Whereas global path planning (which is mainly done offline) broadly lays out a path that reaches the goal point, local collision-avoidance algorithms, which are usually fast, reactive, and carried out online, ensure safety of the vehicle from unexpected and unforeseen obstacles/collisions. Even though many techniques for both global and local collision avoidance have been proposed in the recent literature, there is a great interest around the globe to solve this important problem comprehensively and efficiently and such techniques are still evolving. This paper presents a brief overview of a few promising and evolving ideas on collision avoidance for unmanned aerial vehicles, with a preferential bias toward local collision avoidance.

Using Distance Sensors to Perform Collision Avoidance Maneuvres on Uav Applications

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2017

The Unmanned Aerial Vehicles (UAV) and its applications are growing for both civilian and military purposes. The operability of an UAV proved that some tasks and operations can be done easily and at a good cost-efficiency ratio. Nowadays, an UAV can perform autonomous missions. It is very useful to certain UAV applications, such as meteorology, vigilance systems, agriculture, environment mapping and search and rescue operations. One of the biggest problems that an UAV faces is the possibility of collision with other objects in the flight area. To avoid this, an algorithm was developed and implemented in order to prevent UAV collision with other objects. “Sense and Avoid” algorithm was developed as a system for UAVs to avoid objects in collision course. This algorithm uses a Light Detection and Ranging (LiDAR), to detect objects facing the UAV in mid-flights. This light sensor is connected to an on-board hardware, Pixhawk’s flight controller, which interfaces its communications with ...

Comparison of Unmanned Aerial System Collision Avoidance Algorithms in a Simulated Environment

Journal of Guidance, Control, and Dynamics, 2013

In the field of unmanned aerial vehicles (UAVs), several control processes must be active to maintain safe, autonomous flight. When flying multiple UAVs simultaneously, these aircraft must be capable of performing mission tasks while maintaining a safe distance from each other and obstacles in the air. Despite numerous proposed collision avoidance algorithms, there is little research comparing these algorithms in a single environment. This paper outlines a system built on the Robot Operating System (ROS) environment that allows for control of autonomous aircraft from a base station. This base station allows a researcher to test different collision avoidance algorithms in both the real world and simulated environments. Data is then gathered from three prominent collision avoidance algorithms based on safety and efficiency metrics. These simulations use different configurations based on airspace size and number of UAVs present at the start of the test. The three algorithms tested in this paper are based on mixed integer linear programming (MILP), the A* algorithm, and artificial potential fields. The results show that MILP excelled with a small number of aircraft on the field, but has computation issues with a large number of aircraft. The A* algorithm struggled with small field sizes but performed very well with a larger airspace. Artificial potential fields maintained strong performance across all categories because of the algorithm's handling of many special cases. While no algorithms were perfect, these algorithms demonstrated the ability to handle up to eight aircraft on a 500 meter square field and sixteen aircraft safely on a 1000 meter square field. I've needed to make it this far. He's guided me every step of the way, and without him, this would not have been possible. I would like to express my deepest gratitude to Dr. Biaz for his guidance, support, and opportunity to work with him during my graduate studies at Auburn University. I would also like to thank all the members of the Auburn 2011 REU site for their algorithms development that made this study possible:

Autonomous unmanned aircraft collision avoidance system based on geometric intersection

Autonomous Unmanned Aerial Vehicles (UAVs) are envisioned as an integral part of future urban civil and military applications. Large and small scale UAVs will perform large variety of autonomous tasks. However, the capability of UAVs to navigate completely autonomous in real environment is still in its infancy. Autonomous collision avoidance is a necessary step toward this goal. This paper introduces a new collision avoidance approach based on geometrical intersection method for the estimation of collision risk. The approach forms the last line of defense against air-to-air collisions. When a UAV encounters other aircraft that is estimated to approach closer than the minimum safety margin, the resolution unit will be activated in which the direction commands of each UAV in a conflict will be generated, leading to cooperative maneuvering. UAVs flying in a shared airspace are assumed to be linked by real time data bases to share the information of each other and to send and receive th...

Speed Approach for UAV Collision Avoidance

Journal of Physics: Conference Series

The article represents a new approach of defining potential collision of two or more UAVs in a common aviation area. UAVs trajectories are approximated by two or three trajectories' points obtained from the ADS-B system. In the process of defining meeting points of trajectories, two cutoff values of the critical speed range, at which a UAVs collision is possible, are calculated. As calculation expressions for meeting points and cutoff values of the critical speed are represented in the analytical form, even if an on-board computer system has limited computational capacity, the time for calculation will be far less than the time of receiving data from ADS-B. For this reason, calculations can be updated at each cycle of new data receiving, and the trajectory approximation can be bounded by straight lines. Such approach allows developing the compact algorithm of collision avoidance, even for a significant amount of UAVs (more than several dozens). To proof the research adequacy, modeling was performed using a software system developed specifically for this purpose.