Drones and Autonomous Vehicles Open Access

Review on Drone-Assisted Air-Quality Monitoring Systems

Drone-aided systems have gained popularity in the last few decades due to their stability in various commercial sectors and military applications. The conventional ambient air quality monitoring stations (AAQMS) are immovable and big. This drawback has been significantly overcome by drone-aided low-cost sensor (LCS) modules. As a result, much research work, media information, and technical notes have been released on drone-aided air quality and ecological monitoring and mapping applications. This work is a sincere effort to provide a comprehensive and structured review of commercial drone applications for air quality and environmental monitoring. The collected scientific and non-scientific information was divided according to the different drone models, sensor types, and payload weights. The payload component is very critical in stablility of the multirotor drones. Most study projects installed inexpensive sensors on drones according to the avilibility of the space on drone frame. After reviewing of multiple environmental applications the common payload range was 0 gm to 4000 gm. The crucial elements are addressed, including their relation to meteorological factors, air isokinetics, propeller-induced downwash, sensor mounting location, ramifications etc. As a result, technical recommendations for AQ monitoring assisted by drones are addressed in the debate part. This work will help researchers and environmentalists choose sensor-specific payloads for drones and mounting locations. Also, it enables advanced methods of monitoring parameters that help policymakers to frame advanced protocols and sensor databases for the environment and ecology.

Evaluating Different UAS Flight Methods for 3D Model Generation and Printing of a Tornado Destroyed Cultural Heritage: Caddo House in Texas

In recent years, the use of Unmanned Aerial Systems (UAS) to obtain imagery for photogrammetry has become commonplace. Using these data to develop 3D products has also grown significantly in both research and commercial applications. This study aims to find a relatively simple and low cost UAS flight method as a means to obtain data to produce a 3D model suitable for 3D printing. The study subject chosen to assess different flight methods was the Caddo House at Caddo Mounds State Historical Site located near Alto, Cherokee County, Texas, USA. To collect images for analysis, a DJI Phantom 4 Pro UAS was used with Pix4DCapture mission control app. Two main missions were carried out, one being a pre-defined double-grid flight, and the other being an orbital free-flight method. The findings of this study indicate that if the goal is to create a true-to-life 3D model of an object using UAS, the best method would be a curated orbital free-flight method. If there is time constraint and the subject is sufficiently large and not considerably irregular, a double-grid mission with sufficient forward and side overlap can produce desirable results, but with a slight loss of fine details. The 3D model developed from the curated orbital flight method was successfully printed with a customer grade FDM 3D printer.

A Lightweight Visual Navigation and Control Approach to the 2022 RoboMaster Intelligent UAV Championship

In this paper, an autonomous system is developed for drone racing. On account of their vast consumption of computing resources, the methods for visual navigation commonly employed are discarded, such as visual-inertial odometry (VIO) or simultaneous localization and mapping (SLAM). A series of navigation algorithms for autonomous drone racing, which can operate without the aid of the information on the external position, are proposed: one for lightweight gate detection, achieving gates detection with a frequency of 60 Hz; one for direct collision detection, seeking the maximum passability in-depth images. Besides, a velocity planner is adopted to generate velocity commands according to the results from visual navigation, which are enabled to perform a guidance role when the drone is approaching and passing through gates, assisting it in avoiding obstacles and searching for temporarily invisible gates. The approach proposed above has been demonstrated to successfully help our drone passing-through complex environments with a maximum speed of 2.5 m/s and ranked first at the 2022 RoboMaster Intelligent UAV Championship.

Conceptual Design of Aerostat-Based Autonomous Docking and Battery Swapping System for Extended Airborne Operation

In response to the ever-growing global demand for Unmanned Aerial Vehicles, efficient battery solutions have become vital. This paper proposes a design and concept of an Autonomous Mid Air Battery Swapping System for Vertical Take-Off and Landing Unmanned Aerial Vehicles. The proposed design integrates Aerial Mechatronics, Lighter than Air Systems, and Digital Modelling by leveraging the innovative concept of aerostats for battery swapping. This adaptive and effective technology paves the way for the next generation of autonomous Vertical Take-Off and Landing, ensuring a longer flight time and range. Modern-day technologies have empowered Unmanned Aerial Vehicles to operate autonomously and be remotely controlled, expanding their utility across diverse industries. The enhanced Vertical Take-Off and Landing capabilities include the ability to dock on an aerostat-mounted system, facilitating seamless battery swapping without human intervention and ensuring extended flight duration and operational flexibility. These advancements promise to broaden the applications of Unmanned Aerial Vehicles across various industries.

Image Fusion Capability from Different Cameras for UAV in Cultural Heritage Applications

In this paper, image fusion is performed by utilizing images derived from different cameras for the unmanned aerial vehicle (UAV). By producing the fused image, the spatial resolution of the multispectral (MS) image is improved on the one hand and the classification accuracy on the other hand. First, however, the horizontal and vertical accuracy of the generated products, orthophoto mosaics, and digital surface models, is determined using checkpoints that do not participate in the processing of the image blocks. Also, the changes of these accuracies with a 50% increase (or decrease) of the UAV's flight height are determined. The study area is the Early Christian Basilica C and the flanking Roman buildings, at the archaeological site of Amphipolis (Eastern Macedonia, Greece).

Drones and Autonomous Vehicles — A New Open-access Journal for Multidisciplinary Research on Autonomous Systems

ℒ₁ Adaptive Control of Quadrotor UAVs in Case of Inversion of the Torque Direction

This paper presents a method for fault tolerant control of quadrotor UAVs in case of inversion of the torque direction, a situation that might occur due to structural, hardware or software issues. The proposed design is based on multiple-model ℒ₁ adaptive control. The controller is composed of a nominal reference model and a set of degraded reference models. The nominal model is that with desired dynamics that are optimal regarding some specific criteria. In a degraded model, the performance criteria are reduced. It is designed to ensure system robustness in the presence of critical failures. The controller is tested in simulations and it is shown that the multiple model ℒ₁ adaptive controller stabilizes the system in case of inversion of the control input, while the ℒ₁ adaptive controller with a single nominal model fails.

Designing a Quadcopter for Fire and Temperature Detection with an Infrared Camera and PIR Sensor

In agriculture, medicine, and engineering, sudden fire outbreaks are prevalent. During such events, the ensuing fire spread is extensive and unpredictable, necessitating crucial data for effective response and control. To address this need, the current initiative focuses on utilizing an Unmanned Aerial Vehicle (UAV) with an Infrared (IR) sensor. This sensor detects and analyses temperature variations, accompanied by additional camera footage capturing thermal images to pinpoint the locations of the incidents precisely. The UAV’s programming is executed using Arduino-Nano and mission planner software, interfacing with the Pixhawk flight controller operating in a guided mode for autonomous navigation. The UAV configuration includes a radio module interfacing with Arduino-Nano, a flight controller, and remote-control functionality. The flight duration is approximately 10–15 min, contingent upon flight dynamics and environmental temperature. Throughout its airborne operation, the UAV transmits live telemetry and log feeds to the connected computer, displaying critical parameters such as altitude, temperature, battery status, vertical speed, and distance from the operator. The Pixhawk flight controller is specifically programmed to govern the UAV’s behavior, issuing warnings to the pilot in case of low voltage, prompting a timely landing to avert potential crashes. In case of in-flight instability or a crash, the mission planner can trace the UAV’s location, facilitating efficient recovery and minimizing costs and component availability losses. This integrated approach enhances situational awareness and mitigation strategies, offering a comprehensive solution for managing fire incidents in diverse fields.

An Architecture for Early Wildfire Detection and Spread Estimation Using Unmanned Aerial Vehicles, Base Stations, and Space Assets

This paper presents, an autonomous and scalable monitoring system for early detection and spread estimation of wildfires by leveraging low-cost UAVs, satellite data and ground sensors. An array of ground sensors, such as fixed towers equipped with infrared cameras and IoT sensors strategically placed in areas with a high probability of wildfire, will work in tandem with the space domain as well as the air domain to generate an accurate and comprehensive flow of information. This system-of-systems approach aims to take advantage of the key benefits across all systems while ensuring seamless cooperation. Having scalability and effectiveness in mind, the system is designed to work with low-cost COTS UAVs that leverage infrared and RGB sensors which will act as the primary situational awareness generator on demand. AI task allocation algorithms and swarming-oriented area coverage methods are at the heart of the system, effectively managing the aerial assets High-level mission planning takes place in the GCS, where information from all sensors is gathered and compiled into a user-understandable schema. In addition, the GCS issues warnings for events such as the detection of fire and hardware failures, live video feed and lower-level control of the swarm and IoT sensors when requested. By performing intelligent sensor fusion, this solution will offer unparalleled reaction times to wildfires while also being resilient and reconfigurable should any hardware failures arise by incorporating state of the art swarming capabilities.

Enhancing the Monitoring Protocols of Intermittent Flow Rivers with UAV-Based Optical Methods to Estimate the River Flow and Evaluate Their Environmental Status

Temporary streams are a key component of the hydrological cycle in arid and semi-arid regions, but their flow is highly variable and difficult to measure. In this paper, we present a novel approach that could be used to assess the flow of temporary streams this allowing to characterize their environmental status. Specifically, we apply the Image Velocimetry (IV) method to estimate surface velocity in temporary streams using Unmanned Aerial Vehicles (UAVs) equipped with optical sensors (IV-UAV method). The IV-UAV method enables the easy, safe and quick estimation of the velocity on the water’s surface. This method was applied in different temporary streams in Lesvos Island, Greece. The results obtained indicate that the IV-UAV can be implemented at low discharges, temporary streams and small streams. Specifically, the water depth ranged from 0.02 m to 0.28 m, while the channel width ranged from 0.6 m to 4.0 m. The estimated surface velocity ranged from 0.0 to 5.5 m/s; thus, the maximum water discharge was 0.60 m³/s for the largest monitored stream of the island. However, there were many occasions that measurements were unable due to various reasons such as dense vegetation or archaeological sites. Despite of this, the proposed methodology could be incorporated in optical protocols which are used to assess the environmental status of temporary streams of Mediterranean conditions. Finally, this would become a valuable tool for understanding the dynamics of these ecosystems and monitoring changes over time.

An Architecture for Early Wildfire Detection and Spread Estimation Using Unmanned Aerial Vehicles, Base Stations, and Space Assets

This paper presents, an autonomous and scalable monitoring system for early detection and spread estimation of wildfires by leveraging low-cost UAVs, satellite data and ground sensors. An array of ground sensors, such as fixed towers equipped with infrared cameras and IoT sensors strategically placed in areas with a high probability of wildfire, will work in tandem with the space domain as well as the air domain to generate an accurate and comprehensive flow of information. This system-of-systems approach aims to take advantage of the key benefits across all systems while ensuring seamless cooperation. Having scalability and effectiveness in mind, the system is designed to work with low-cost COTS UAVs that leverage infrared and RGB sensors which will act as the primary situational awareness generator on demand. AI task allocation algorithms and swarming-oriented area coverage methods are at the heart of the system, effectively managing the aerial assets High-level mission planning takes place in the GCS, where information from all sensors is gathered and compiled into a user-understandable schema. In addition, the GCS issues warnings for events such as the detection of fire and hardware failures, live video feed and lower-level control of the swarm and IoT sensors when requested. By performing intelligent sensor fusion, this solution will offer unparalleled reaction times to wildfires while also being resilient and reconfigurable should any hardware failures arise by incorporating state of the art swarming capabilities.utf-8

Review on Drone-Assisted Air-Quality Monitoring Systems

Drone-aided systems have gained popularity in the last few decades due to their stability in various commercial sectors and military applications. The conventional ambient air quality monitoring stations (AAQMS) are immovable and big. This drawback has been significantly overcome by drone-aided low-cost sensor (LCS) modules. As a result, much research work, media information, and technical notes have been released on drone-aided air quality and ecological monitoring and mapping applications. This work is a sincere effort to provide a comprehensive and structured review of commercial drone applications for air quality and environmental monitoring. The collected scientific and non-scientific information was divided according to the different drone models, sensor types, and payload weights. The payload component is very critical in stablility of the multirotor drones. Most study projects installed inexpensive sensors on drones according to the avilibility of the space on drone frame. After reviewing of multiple environmental applications the common payload range was 0 gm to 4000 gm. The crucial elements are addressed, including their relation to meteorological factors, air isokinetics, propeller-induced downwash, sensor mounting location, ramifications etc. As a result, technical recommendations for AQ monitoring assisted by drones are addressed in the debate part. This work will help researchers and environmentalists choose sensor-specific payloads for drones and mounting locations. Also, it enables advanced methods of monitoring parameters that help policymakers to frame advanced protocols and sensor databases for the environment and ecology.utf-8

Multi-Robot Cooperative Target Search Based on Distributed Reinforcement Learning Method in 3D Dynamic Environments

This paper proposes a distributed reinforcement learning method for multi-robot cooperative target search based on policy gradient in 3D dynamic environments. The objective is to find all hostile drones which are considered as targets with the minimal search time while avoiding obstacles. First, the motion model for unmanned aerial vehicles and obstacles in a dynamic 3D environments is presented. Then, a reward function is designed based on environmental feedback and obstacle avoidance. A loss function and its gradient are designed based on the expected cumulative reward and its differentiation. Next, the expected cumulative reward is optimized by a reinforcement learning algorithm that makes the loss function update in the direction of the gradient. When the variance of the expected cumulative reward is lower than a specified threshold, the unmanned aerial vehicle obtains the optimal search policy. Finally, simulation results demonstrate that the proposed method effectively enables unmanned aerial vehicles to identify all targets in the dynamic 3D airspace while avoiding obstacles.utf-8

Evaluating Different UAS Flight Methods for 3D Model Generation and Printing of a Tornado Destroyed Cultural Heritage: Caddo House in Texas

In recent years, the use of Unmanned Aerial Systems (UAS) to obtain imagery for photogrammetry has become commonplace. Using these data to develop 3D products has also grown significantly in both research and commercial applications. This study aims to find a relatively simple and low cost UAS flight method as a means to obtain data to produce a 3D model suitable for 3D printing. The study subject chosen to assess different flight methods was the Caddo House at Caddo Mounds State Historical Site located near Alto, Cherokee County, Texas, USA. To collect images for analysis, a DJI Phantom 4 Pro UAS was used with Pix4DCapture mission control app. Two main missions were carried out, one being a pre-defined double-grid flight, and the other being an orbital free-flight method. The findings of this study indicate that if the goal is to create a true-to-life 3D model of an object using UAS, the best method would be a curated orbital free-flight method. If there is time constraint and the subject is sufficiently large and not considerably irregular, a double-grid mission with sufficient forward and side overlap can produce desirable results, but with a slight loss of fine details. The 3D model developed from the curated orbital flight method was successfully printed with a customer grade FDM 3D printer.utf-8

Designing a Quadcopter for Fire and Temperature Detection with an Infrared Camera and PIR Sensor

In agriculture, medicine, and engineering, sudden fire outbreaks are prevalent. During such events, the ensuing fire spread is extensive and unpredictable, necessitating crucial data for effective response and control. To address this need, the current initiative focuses on utilizing an Unmanned Aerial Vehicle (UAV) with an Infrared (IR) sensor. This sensor detects and analyses temperature variations, accompanied by additional camera footage capturing thermal images to pinpoint the locations of the incidents precisely. The UAV’s programming is executed using Arduino-Nano and mission planner software, interfacing with the Pixhawk flight controller operating in a guided mode for autonomous navigation. The UAV configuration includes a radio module interfacing with Arduino-Nano, a flight controller, and remote-control functionality. The flight duration is approximately 10–15 min, contingent upon flight dynamics and environmental temperature. Throughout its airborne operation, the UAV transmits live telemetry and log feeds to the connected computer, displaying critical parameters such as altitude, temperature, battery status, vertical speed, and distance from the operator. The Pixhawk flight controller is specifically programmed to govern the UAV’s behavior, issuing warnings to the pilot in case of low voltage, prompting a timely landing to avert potential crashes. In case of in-flight instability or a crash, the mission planner can trace the UAV’s location, facilitating efficient recovery and minimizing costs and component availability losses. This integrated approach enhances situational awareness and mitigation strategies, offering a comprehensive solution for managing fire incidents in diverse fields.utf-8

Medical Drones for Public Health Emergency Preparedness, Response, and Resilience: Delivering Health for All

Amid a global metacrisis of health, environmental and economic challenges, medical delivery drones (or uncrewed aerial vehicles) offer a promising method to prepare for, and rapidly respond, to future emergencies. This opinion article summarizes the current medical delivery drone landscape, evidence base, and policy implications in the context of public health emergencies, such as pandemics, natural disasters, and humanitarian crises, with a particular emphasis on the region of sub-Saharan Africa. Using a multilateral, international health policy perspective, key challenges and opportunities, such as the development of sustainable funding mechanisms, robust regulatory frameworks, and capacity building, are identified.utf-8

ℒ₁ Adaptive Control of Quadrotor UAVs in Case of Inversion of the Torque Direction

This paper presents a method for fault tolerant control of quadrotor UAVs in case of inversion of the torque direction, a situation that might occur due to structural, hardware or software issues. The proposed design is based on multiple-model ℒ₁ adaptive control. The controller is composed of a nominal reference model and a set of degraded reference models. The nominal model is that with desired dynamics that are optimal regarding some specific criteria. In a degraded model, the performance criteria are reduced. It is designed to ensure system robustness in the presence of critical failures. The controller is tested in simulations and it is shown that the multiple model ℒ₁ adaptive controller stabilizes the system in case of inversion of the control input, while the ℒ₁ adaptive controller with a single nominal model fails.utf-8

Exact and Heuristic Approaches to Surveillance Routing with a Minimum Number of Drones

The rising cost and scarcity of human labor pose challenges in security patrolling tasks, such as facility security. Drones offer a promising solution to replace human patrols. This paper proposes two methods for finding the minimum number of drones required for efficient surveillance routing: an ILP-based method and a greedy method. We evaluate these methods through experiments, comparing the minimum number of required drones and algorithm runtime. The findings indicate that the ILP-based method consistently yields the same or a lower number of drones needed for surveillance compared to the greedy method, with a 73.3% success rate in achieving better results. However, the greedy method consistently finishes within one second, whereas the ILP-based method sometimes significantly increases when dealing with 14 more locations. As a case study, we apply the greedy method to identify the minimum drone surveillance route for the Osaka-Ibaraki Campus of Ritsumeikan University.utf-8

An Integer Programming Approach to Multi-Trip Routing of Delivery Drones at Load-Dependent Flight Speed

In recent years, there has been a growing interest in utilizing drones for parcel delivery among companies, aiming to address logistical challenges. However, effective optimization of delivery routes is essential. A theoretical framework termed the Flight Speed-aware Vehicle Routing Problem (FSVRP) has emerged to address the variability in drone flight speed based on payload weight. Several approximate methods have been proposed to solve the FSVRP. Our research endeavors to optimize parcel delivery efficiency and reduce delivery times by introducing a novel delivery problem. This problem accounts for multiple deliveries while considering the variability in flight speed due to diverse payloads. Through experimentation, we evaluate the efficacy of our proposed method compared to existing approaches. Specifically, we assess total flight distance and flight time. Our findings indicate that even in cases where the payload exceeds maximum capacity, all parcels can be delivered through multiple trips. Furthermore, employing a multi-trip FSVRP approach results in an average reduction of 10% in total flight time, even when payload capacities are not exceeded.utf-8

Drones and Autonomous Vehicles — A New Open-access Journal for Multidisciplinary Research on Autonomous Systems