Distributed formation control of multi-UAV systems using relative information

In this article simultaneous arrival of multiple unmanned aerial vehicle (UAV) at a common point was studied in a fixed network hierarchy is used. By considering the model of fixed wing UAV the decentralized based control algorithm is developed for the formation control of all UAV’s. The tree based networked geometry is developed for the formation control of multiple UAV’s with respect to the leader. Whereas, UAV’s agent or (leader / follower) are autonomously connected with each other. Formation of flight via decentralized control structure which contains two parts, one is to achieve the arrival of expected meet-point for the formation geometry and other is to maintain the synchronization of all UAV’s. Moreover, the leader is supposed and able to regulate the speed or velocity of UAV’s. Simulated results showed that arrival of multiple UAV’s at a common point for the formation is achieved successfully and the above designed control algorithm has good robustness and flexible.

Due to its high manoeuvrability, portable size, high payload capability and good expandability, Unmanned Aerial Vehicle (UAV) is capable of accomplishing varieties of tough missions. In particular, cooperative multiple UAVs can significantly increase the mission efficiency and effectiveness. In some applications with complex environments such as narrow canyon, distributed formation with adjustable shape is required. Moreover, a reliable autopilot safety system is mandatory so that the flight does not pose threats to the surrounding environment. In this research, distributed formation control of multiple UAVs with built-in comprehensive safety features for operation in complex environment is studied. Distributed formation control has been studied in an existing work by integrating proportional control into its path planner. There exists, however, steady state errors when an external reference velocity is applied to a certain UAV. In order to improve the formation control and eliminate the steady-state error, a proportional-integral (PI) controller is proposed. It is shown that the proposed distributed PI controller can stabilize the system and achieve the zero steady-state error. Numerical and hardware in the loop (HIL) simulations and flight tests are conducted to verify the effectiveness of the proposed approach. Since distributed formation is controlled by an on-board autopilot, failures may happen due to system or hardware faults. Hence, safety and robustness of the on-board autopilot become very important. Therefore a comprehensive approach on the implementation of safety operation for multiple UAVs formation in outdoor environments is proposed. A pre-flight UAV status inspection schedule and a hierarchical three layers in-flight safety architecture are developed based on a customized risk assessment matrix.

Hybrid modeling and control issues provide a flexible powerful tool for Unmanned Aerial Vehicles (UAVs) as complex control platforms. This paper aims to briefly review recent results in this area. Firstly, existing works on hybrid modeling and control of a single UAV are reviewed. Then multiple UAVs control in a synchronously cooperative task planning, which gives much more maneuverability, has been surveyed in the hybrid framework. Formation control of UAVs is a typical cooperative strategy with considerable applications in multi-agent aerial robotics area and can leverage limited abilities of single UAVs into complicated tasks of group missions. There are a few works in this field which we briefly reviewed their results and explored the possible future directions of these research activities.

The development of hierarchical structures of unmanned aerial vehicles (UAVs) increases the efficiency of unmanned aerial systems. The grouping of UAVs increases the region of recognition or force of assault. Achieving these requirements is possible through a UAV formation. The UAVs in the formation must be controlled and managed by a commander, but the commander cannot control individual UAVs. The UAVs within the formation have assigned specific individual tasks, so is possible to achieve the flight of the formation with minimum collisions between UAVs and maximized equipment utilization. This paper aims to present a method of formation control for multiple UAVs that allows dynamic changes in the constellations of UAVs. The article includes the results of tests and research conducted in real-world conditions involving a formation capable of adapting its configuration. The results are presented as an element of research for the autonomy swarm, which can be controlled by one pilot/operator. The control of a swarm consisting of many UAVs (several hundred) by one person is now a current problem. The article presents a fragment of research work on high-autonomy UAV swarms. Here is presented a field test that focuses on UAV constellation control.

Recent advancements in technology have led to a great interest in the use of Unmanned Aerial Vehicles (UAVs) for a vast array of applications such as real time site monitoring, target search and destroy and UAVs being used as mobile sinks to collect data from Internet of Things (IoT) devices. This is mainly due to their autonomy, high mobility, ease of deployment and affordable nature. A group of UAVs can be used collectively to bring a coordinated effort in task execution, allowing more tasks to be completed in a wider area and in the shortest possible time. However, using multiple UAVs presents some challenges for efficient cooperation. UAVs are resource constrained due to being battery powered and this limits the permissible flight time. Therefore, it is necessary to intelligently manage their operation given the limited resources and other constraints associated with the mission. In this paper, we propose a multi-objective UAV task assignment model to support spatio-temporally distributed events raised by static IoT devices, using a discrete Non- Dominated Sorting Genetic Algorithm II (NSGA-II). This model assigns the most suitable UAV(s) to serve at the different event locations ensuring that none of the constraints are violated. The performance of the algorithm was evaluated through numerical simulations and compared to a similar implementation using Mixed Integer Linear Programming (MILP). Results show an improvement of 7.9% in the total energy consumption for all UAVs while ensuring that all the temporal constraints are not violated.

In the broad class of unmanned aerial vehicles (UAV), Quadrotor is an important member. Cooperative control of UAVs are currently being researched for a wide range of applications. An active and important research area of cooperative control of multiple UAVs is the formation control. Formation flying is the disciplined flight of two or more aircraft under the command of a flight leader. The main goal is to coordinate a group of UAVs to achieve a desired formation pattern and avoid inter-vehicle collisions at the same time. Formation flight of a team of UAVs has broad applications such as aerial mapping, traffic monitoring, terrain and utilities inspection, search and rescue operations, perimeter planning, disaster monitoring, reconnaissance mission, surveillance etc. Here we propose a Line Of Sight (LOS) guidance based flight formation control strategy for multiple quad rotor UAVs in leader-follower framework. The guidance laws for 2D formation are implemented with the help of LOS angles, between adjacent quadrotors to keep the current quadrotor's position in formation. The full dynamic model of quadrotor incorporating LOS guidance law is considered for designing PID controller and the simulation analysis was done using MATLAB/ Simulink.

Ensuring UAV safety: A deep learning-based fault-tolerant approach with control barrier functions

: Unmanned aerial vehicles (UAVs) are critical components of the future naval forces. UAV control and monitoring with autonomous operation will become an absolute necessity and adaptive cooperation of vehicles is the only practical alternative. The objective of this project is to develop and evaluate new methodologies for cooperative (formation) control of multiple unmanned air vehicles. The goal is to have multiple UAVs working together as a group. Instead of separately assigning distinct tasks to each vehicle, the operator would assign tasks to the UAV group, which then determines the best way to accomplish each task, freeing the operator to maintain surveillance over the entire operation. In this project we investigated Path Tracking and obstacle avoidance of UAVs using fuzzy logic method. Algorithms for close formation control of multi-UAVs are developed and simulated. We also investigated fault-tolerant control of single UAVs by neuro-adaptive method. Detailed description of this method is provided in this document. The project has supported S graduate students with 9 technical papers published.

To archive diverse kinds of goal, multiple unmanned aerial vehicles (UAVs) need to cooperate each other. Therefore, the importance of a ground station becomes more important. This paper proposes a framework of the ground station that controls multiple and hetero UAVs. The framework contains multiple UAV control modules and UI interfaces and has the flexibility for adding diverse kinds of UAVs and embedded devices such as commercial UAVs, Arduino-based UAVs, cameras and storage devices.

Unmanned aerial vehicles (UAVs) are becoming very important platforms for conducting combat operations in the russian-ukrainian war, as they significantly reduce the risk of human life during special and combat missions. The UAV group can be used to perform a wide range of military tasks: destruction of enemy equipment, reconnaissance (monitoring) of the area, construction of aerial networks, etc. In the conditions of a change in the tactical situation, countermeasures by the enemy, effective management of the UAV group is impossible without an appropriate management system. The UAV group can include both unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UAVs). The following main tasks are assigned to the management system: determination and coordination of the order of joint actions of autonomous UAV groups; formation of flight (ground) tasks and flight (movement) trajectories of the UAV group; dynamic adjustment of the flight task and the role of each UAV during its use; organization of the communication network between the control center and between UAV groups, etc. The tasks and target functions of management of each of their subsystems are determined. The features of the UAV group control cycle are described. The main stages of the synthesis of the control system are considered: the choice of the control method (centralized, hierarchical, decentralized and mixed); selection of algorithms (protocols) and organization of the process of data exchange between UAVs. A functional model of the UAV group management system is proposed. Tasks and main management functions of each of the subsystems are defined. Features of the UAV group management cycle are described. The main stages of the synthesis of the control system are considered: the selection of algorithms (protocols) and the organized process of information exchange between UAVs; variants of formation and swarm models of UAV movement in groups; multi-agent decision-making models for the organization of task performance by the UAV group.

The proliferation of unmanned aerial vehicle (UAV) technology has the potential to change the situational awareness of medical incident commanders' (ICs') scene assessment of mass gatherings. Mass gatherings occur frequently and the potential for injury at these events is considered higher than the general population. These events have generated mass-casualty incidents (MCIs) in the past. The aim of this study was to compare UAV technology to standard practice (SP) in scene assessment using paramedic students during a mass-gathering event (MGE). This study was conducted in two phases. Phase One consisted of validation of the videos and accompanying data collection tool. Phase One was completed by 11 experienced paramedics from a provincial Emergency Medical Services (EMS) service. Phase Two was a randomized comparison with 47 paramedic students from the Holland College Paramedicine Program (Charlottetown, Prince Edward Island, Canada) of the two scene assessment systems. For Phase Two, the paramedic students were randomized into a UAV or a SP group. The data collection tool consisted of two board categories: primary importance with 20 variables and secondary importance with 25 variables. After a brief narrative, participants were either shown UAV footage or the ground footage depending on their study group. After completion of the videos, study participants completed the data collection tool. The Phase One validation showed good consensus in answers to most questions (average 79%; range 55%-100%). For Phase Two, a Fisher's exact test was used to compare each variable from the UAV and SP groups using a P value of .05. Phase Two demonstrated a significant difference between the SP and UAV groups in four of 20 primary variables. Additionally, significant differences were found for seven out of 25 secondary variables. This study demonstrated the accurate, safe, and feasible use of a UAV as a tool for scene assessment by paramedic students at an MGE. No observed statistical difference was noted in a majority of both primary and secondary variables using a UAV for scene assessment versus SP.

This paper mainly studies the leader follower formation control problem of multiple vertical takeoff and landing (VTOL) unmanned aerial vehicles (UAVs) under time-varying actuator faults. A hierarchical control strategy is proposed for the underactuated characteristics of VTOL UAVs. Based on Lyapunov stability theory, an adaptive fault-tolerant control scheme for the outer position loop was established to achieve tracking of the target position. A fault-tolerant control strategy for adaptive inner attitude loop was designed using Nussbaum function, achieving tracking of instruction attitude. On the premise of ensuring that the inner loop can quickly track the outer loop, the stability of the entire closed-loop system has been successfully achieved. The simulation results validated the proposed theoretical results.

Introduction Autonomous unmanned aerial vehicles (UAVs) are considered with increasing interest in a diverse set of civil and commercial applications, such as environmental and natural disaster monitoring, border surveillance, emergency assistance, search and rescue missions, delivery of goods, and construction [208, 132, 362, 265, 434, 110, 280, 163]. Use of single or multiple UAVs as communication relays or aerial base stations for network provisioning in emergency situations and for public safety communications has been of particular interest due to UAVs fast deployment and large coverage capabilities [331, 193, 206, 429]. The deployed aerial platform size and the number of necessary platforms are key factors in determining the on-board communication system in addition to the coverage and capacity requirements [73]. Small-scale multi-rotors are of particular interest in practice due to their ease of deployment, low acquisition and maintenance costs, high maneuverability, and ability to hover. Research and development of small-scale UAVs focused initially on control issues, such as flight stability, maneuverability, and robustness, followed by designing autonomous vehicles capable of waypoint flights with minimal user intervention. Considering the limited flight time and payload capacity of these vehicles and the area sizes the aforementioned applications might span, the interest is shifting more and more toward collaborative multiple UAV systems for efficient and successful missions. The number of UAVs might be from tens to hundreds traveling over tens of meters to kilometers for different applications (see Figure 3.1 for an illustration). Wireless communication is an essential factor not only for network provisioning with UAVs but also for successful deployment of systems consisting of multiple small-scale UAVs. It is highly likely that high-performance links and connectivity in three-dimensional space will be required for several applications (e.g., monitoring certain areas) with data delivery meeting a certain quality of service demands [35].The question arises as to which wireless technology should be employed for aerial networks that consist of air-to-ground and air-to-air links, and data needs to be delivered regardless of significant height and orientation differences. Taking into account the quality of service to be satisfied over diverse links and the high node mobility, it is not yet clear as to whether networking protocols developed for ground networks are readily deployable on UAV networks.

On decentralized adaptive full-order sliding mode control of multiple UAVs

A new consensus theory-based method for formation control and obstacle avoidance of UAVs