Distributed reactive collision avoidance for a swarm of quadrotors

2016 ◽  
Vol 231 (6) ◽  
pp. 1035-1055 ◽  
Author(s):  
J Leonard ◽  
A Savvaris ◽  
A Tsourdos
Keyword(s):  
Collision Avoidance ◽  
Large Scale ◽  
Conflict Detection ◽  
Original Method ◽  
Single Vehicle ◽  
Aerial Vehicle ◽  
Resolution Problem ◽  
Conflict Detection And Resolution ◽  
Flight Scheme ◽  
Reactive Collision

The large-scale of unmanned aerial vehicle applications has escalated significantly within the last few years, and the current research is slowly hinting at a move from single vehicle applications to multivehicle systems. As the number of agents operating in the same environment grows, conflict detection and resolution becomes one of the most important factors of the autonomous system to ensure the vehicles’ safety throughout the completion of their missions. The work presented in this paper describes the implementation of the novel distributed reactive collision avoidance algorithm proposed in the literature, improved to fit a swarm of quadrotor helicopters. The original method has been extended to function in dense and crowded environments with relevant spatial obstacle constraints and deconfliction manoeuvres for high number of vehicles. Additionally, the collision avoidance is modified to work in conjunction with a dynamic close formation flight scheme. The solution presented to the conflict detection and Resolution problem is reactive and distributed, making it well suited for real-time applications. The final avoidance algorithm is tested on a series of crowded scenarios to test its performances in close quarters.

scholarly journals COLREGs Compliant Fuzzy-based Collision Avoidance System for Multiple Ship Encounters

2021 ◽  
Author(s):  
Yaseen Adnan Ahmed ◽  
Mohammed Abdul Hannan ◽  
Mahmoud Yasser Oraby ◽  
Adi Maimun
Keyword(s):  
Collision Avoidance ◽  
Conflict Detection ◽  
Collision Risk ◽  
Fuzzy Membership Functions ◽  
Marine Traffic ◽  
Unique Maximum ◽  
Speed Change ◽  
Conflict Detection And Resolution ◽  
Resolution Algorithm ◽  
Collision Avoidance System

As the number of ships for marine transportation increases with the advancement of global trade, encountering multiple ships in marine traffic becomes common. This situation raises the risk of collision of the ships; hence this paper proposes a novel Fuzzy-logic based intelligent conflict detection and resolution algorithm, where the collision courses and possible avoiding actions are analyzed by considering ship motion dynamics and the input and output fuzzy membership functions are derived. As a conflict detection module, the Collision Risk (CR) is measured for each ship by using a scaled nondimensional Distance to the Closest Point of Approach (DCPA) and Time to the Closest Point of Approach (TCPA) as inputs. Afterwards, the decisions for collision avoidance are made based on the calculated CR, encountering angle and relative angle of each ship measured from others. In this regard, the rules for the Fuzzy interface system are defined in accordance with the COLREGs, and the whole system is implemented on the MATLAB Simulink platform. In addition, to deal with the multiple ship encounters, the paper proposes a unique maximum-course and minimum-speed change approach for decision making, which has been found to be efficient to solve Imazu problems, and other complicated multiple-ship encounters.

A VNS metaheuristic for solving the aircraft conflict detection and resolution problem by performing turn changes

2014 ◽  
Vol 63 (3) ◽  
pp. 583-596 ◽  
Author(s):  
Antonio Alonso-Ayuso ◽  
Laureano F. Escudero ◽  
F. Javier Martín-Campo ◽  
Nenad Mladenović
Keyword(s):  
Conflict Detection ◽  
Resolution Problem ◽  
Conflict Detection And Resolution

scholarly journals Quasi-ADS-B Based UAV Conflict Detection and Resolution to Manned Aircraft

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Chin E. Lin ◽  
Ya-Hsien Lai
Keyword(s):  
Avoidance Performance ◽  
Conflict Detection ◽  
Packet Data ◽  
Share Data ◽  
Aerial Vehicle ◽  
Conflict Detection And Resolution ◽  
Low Altitude ◽  
Effective Signal ◽  
Mission Simulation ◽  
Time Division

A Conflict Detection and Resolution (CD&R) system for manned/unmanned aerial vehicle (UAV) based on Automatic Dependent Surveillance-Broadcast (ADS-B) concept is designed and verified in this paper. The 900 MHz XBee-Pro is selected as data transponder to broadcast flight information among participating aircraft in omnirange. Standard Compact Position Report (CPR) format packet data are automatically broadcasted by ID sequencing under Quasi-ADS-B mechanism. Time Division Multiple Access (TDMA) monitoring checks the designated time slot and reallocates the conflict ID. This mechanism allows the transponder to effectively share data with multiple aircraft in near airspace. The STM32f103 microprocessor is designed to handle RF, GPS, and flight data with Windows application on manned aircraft and ground control station simultaneously. Different conflict detection and collision avoidance algorithms can be implemented into the system to ensure flight safety. The proposed UAV/CD&R using Quasi-ADS-B transceiver is tested using ultralight aircraft flying at 100–120 km/hr speed in small airspace for mission simulation. The proposed hardware is also useful to additional applications to mountain hikers for emergency search and rescue. The fundamental function by the proposed UAV/CD&R using Quasi-ADS-B is verified with effective signal broadcasting for surveillance and efficient collision alert and avoidance performance to low altitude flights.

scholarly journals COLREGs Compliant Fuzzy-Based Collision Avoidance System for Multiple Ship Encounters

2021 ◽  
Vol 9 (8) ◽  
pp. 790
Author(s):  
Yaseen Adnan Ahmed ◽  
Mohammed Abdul Hannan ◽  
Mahmoud Yasser Oraby ◽  
Adi Maimun
Keyword(s):  
Collision Avoidance ◽  
Conflict Detection ◽  
Collision Risk ◽  
Fuzzy Membership Functions ◽  
Marine Traffic ◽  
Unique Maximum ◽  
Speed Change ◽  
Conflict Detection And Resolution ◽  
Resolution Algorithm ◽  
Collision Avoidance System

As the number of ships for marine transportation increases with the advancement of global trade, encountering multiple ships in marine traffic becomes common. This situation raises the risk of collision of the ships; hence, this paper proposes a novel Fuzzy-logic based intelligent conflict detection and resolution algorithm, where the collision courses and possible avoiding actions are analysed by considering ship motion dynamics and the input and output fuzzy membership functions are derived. As a conflict detection module, the Collision Risk (CR) is measured for each ship by using a scaled nondimensional Distance to the Closest Point of Approach (DCPA) and Time to the Closest Point of Approach (TCPA) as inputs. Afterwards, the decisions for collision avoidance are made based on the calculated CR, encountering angle and relative angle of each ship measured from others. In this regard, the rules for the Fuzzy interface system are defined in accordance with the COLREGs, and the whole system is implemented on the MATLAB Simulink platform. In addition, to deal with the multiple ship encounters, the paper proposes a unique maximum-course and minimum-speed change approach for decision making, which has been found to be efficient to solve Imazu problems, and other complicated multiple-ship encounters.

Conflict Monitoring Across the Life Span

2014 ◽  
Vol 28 (3) ◽  
pp. 124-135 ◽  
Author(s):  
Daniela Czernochowski
Keyword(s):  
Older Adults ◽  
Life Span ◽  
Age Groups ◽  
Conflict Detection ◽  
Response Conflict ◽  
Conflict Monitoring ◽  
Subsequent Performance ◽  
Additional Control ◽  
Performance Response ◽  
Conflict Detection And Resolution

Errors can play a major role for optimizing subsequent performance: Response conflict associated with (near) errors signals the need to recruit additional control resources to minimize future conflict. However, so far it remains open whether children and older adults also adjust their performance as a function of preceding response conflict. To examine the life span development of conflict detection and resolution, response conflict was elicited during a task-switching paradigm. Electrophysiological correlates of conflict detection for correct and incorrect responses and behavioral indices of post-error adjustments were assessed while participants in four age groups were asked to focus on either speed or accuracy. Despite difficulties in resolving response conflict, the ability to detect response conflict as indexed by the Ne/ERN component was expected to mature early and be preserved in older adults. As predicted, reliable Ne/ERN peaks were detected across age groups. However, only for adults Ne/ERN amplitudes associated with errors were larger compared to Nc/CRN amplitudes for correct trials under accuracy instructions, suggesting an ongoing maturation in the ability to differentiate levels of response conflict. Behavioral interference costs were considerable in both children and older adults. Performance for children and older adults deteriorated rather than improved following errors, in line with intact conflict detection, but impaired conflict resolution. Thus, participants in all age groups were able to detect response conflict, but only young adults successfully avoided subsequent conflict by up-regulating control.

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