Multi-rotor UAV Research Articles

A Deep Learning Approach of Intrusion Detection and Tracking with UAV-Based 360° Camera and 3-Axis Gimbal

Intrusion detection is often used in scenarios such as airports and essential facilities. Based on UAVs equipped with optical payloads, intrusion detection from an aerial perspective can be realized. However, due to the limited field of view of the camera, it is difficult to achieve large-scale continuous tracking of intrusion targets. In this study, we proposed an intrusion target detection and tracking method based on the fusion of a 360° panoramic camera and a 3-axis gimbal, and designed a detection model covering five types of intrusion targets. During the research process, the multi-rotor UAV platform was built. Then, based on a field flight test, 3043 flight images taken by a 360° panoramic camera and a 3-axis gimbal in various environments were collected, and an intrusion data set was produced. Subsequently, considering the applicability of the YOLO model in intrusion target detection, this paper proposes an improved YOLOv5s-360ID model based on the original YOLOv5-s model. This model improved and optimized the anchor box of the YOLOv5-s model according to the characteristics of the intrusion target. It used the K-Means++ clustering algorithm to regain the anchor box that matches the small target detection task. It also introduced the EIoU loss function to replace the original CIoU loss function. The target bounding box regression loss function made the intrusion target detection model more efficient while ensuring high detection accuracy. The performance of the UAV platform was assessed using the detection model to complete the test flight verification in an actual scene. The experimental results showed that the mean average precision (mAP) of the YOLOv5s-360ID was 75.2%, which is better than the original YOLOv5-s model of 72.4%, and the real-time detection frame rate of the intrusion detection was 31 FPS, which validated the real-time performance of the detection model. The gimbal tracking control algorithm for intrusion targets is also validated. The experimental results demonstrate that the system can enhance intrusion targets’ detection and tracking range.

D-FFP: A directional force field protocol for the efficient management of aerial conflicts between UAVs

Airspace management is currently experiencing significant legislative changes in many countries due to the high complexity of the procedures involved, and the need to guarantee high levels of flight safety, particularly in urban air spaces. In this regard, both strategic and tactical conflict management solutions are being devised to handle conflicts between different UAVs. In this paper, we propose a solution for tactical conflict management that seeks to avoid collisions between UAVs while introducing low complexity in terms of calculations involved and protocol requirements. Our solution specifically addresses multirotor UAVs, and seeks to accelerate the handling of possible conflicts in aerial traffic corridors, which are the most critical scenarios envisioned for the near future due to the high density of UAVs in such spaces. Experimental results obtained in both MATLAB and our realistic drone simulator, ArduSim, evidence the advantages of our solution against previous approaches when solving collisions in a 2D plane. In addition, we propose a 3D extension to handle flight conflicts in more complex scenarios while guaranteeing that floor and ceiling flight limits are adequately enforced.

Dynamic Flight Tracking: Designing System for Multirotor UAVs With Pixhawk Autopilot Data Verification

Dynamic Flight Tracking: Designing System for Multirotor UAVs With Pixhawk Autopilot Data Verification

Event-Triggered Sliding-Mode Control for Consensus Tracking of Nonlinear Multi-Rotor UAVs With Disturbances

Event-Triggered Sliding-Mode Control for Consensus Tracking of Nonlinear Multi-Rotor UAVs With Disturbances

Reinforcement Learning-Based Dynamic Coverage Control of Multi-Rotor UAVs With Safety Priority

Reinforcement Learning-Based Dynamic Coverage Control of Multi-Rotor UAVs With Safety Priority

Data-driven identification of quadrotor dynamics: a tutorial

In this work, we provide a tutorial-style exposition of quadrotor dynamics model identification from experimental data collected in closed-loop. Our objective is to provide guidelines for the scientist who is approaching model-based fight control design for multirotor UAVs for which a model is not readily available, but also to provide instructors with pedagogical material that can be utilized to develop experiential learning opportunities complementing face-to-face lectures in the system identification and control engineering curricula.

Precise Motion Compensation Approach for High-Resolution Multirotor UAV SAR in the Presence of Multiple Errors

Precise Motion Compensation Approach for High-Resolution Multirotor UAV SAR in the Presence of Multiple Errors

Flight Simulation Assessment of a Novel FW-MR Hybrid Agriculture Drone

Agriculture is a sector in Malaysia where the usage of drones has been widespread throughout seeding, surveying, and crop spraying. It has been well known that the current usage of drones in pineapple farms specifically in Malaysia can be further improved upon. This novel design combines the long flight capabilities of fixed-wing aircraft with the efficiency of the common multirotor UAV hence it is a hybrid of both. The methodology of this research uses flight simulations to extract the data concerned with its flying quality such as coefficient of lift, drag, and moments. This research evaluates the longitudinal stability within the computationally simulated data extracted from a mission-profiled flight. The aim of this is the understanding of practical uses as well as the modification needed prior to manufacture.

Commonality Evaluation and Prediction Study of Light and Small Multi-Rotor UAVs

Light small-sized, multi-rotor UAVs, with their notable advantages of portability, intelligence, and low cost, occupy a significant share in the civilian UAV market. To further reduce the full lifecycle cost of products, shorten development cycles, and increase market share, some manufacturers of these UAVs have adopted a series development strategy based on the concept of commonality in design. However, there is currently a lack of effective methods to quantify the commonality in UAV designs, which is key to guiding commonality design. In view of this, our study innovatively proposes a new UAV commonality evaluation model based on the basic composition of light small-sized multi-rotor UAVs and the theory of design structure matrices. Through cross-evaluations of four models, the model has been confirmed to comprehensively quantify the degree of commonality between models. To achieve commonality prediction in the early stages of multi-rotor UAV design, we constructed a commonality prediction dataset centered around the commonality evaluation model using data from typical light small-sized multi-rotor UAV models. After training this dataset with convolutional neural networks, we successfully developed an effective predictive model for the commonality of new light small-sized multi-rotor UAV models and verified the feasibility and effectiveness of this method through a case application in UAV design. The commonality evaluation and prediction models established in this study not only provide strong decision-making support for the series design and commonality design of UAV products but also offer new perspectives and tools for strategic development in this field.

The Design and Development of a UAV’s Micro-Turbogenerator System and the Associated Control Testing Bench

A study on the possibility of integrating a micro-turbogenerator system into a multi-rotor UAV platform was performed along with a performance evaluation of the result. This paper presents the design and development of a micro-turbogenerator system constructed from commercially available components and the associated test bench that was needed to validate the system. The goal of the micro-turbogenerator system was to replace the electrical power source (the batteries) of an experimental UAV. Substituting the electrical power source with a hybrid propulsion system has the potential to enhance the UAV’s endurance and functionality, rendering it more versatile and efficient. The hybrid propulsion system involves the use of a commercially available micro-gas turbine that propels an electric generator, supplying the required electrical power for the UAV’s electric propulsion system. Integrating this micro-turbogenerator system ensures a substantial increase in UAV endurance. The test bench was used to assess the performance of the micro-turbogenerator system and formulate a control law necessary for maintaining a balance between the power generated by the system and the power consumed by the UAV. The developed test bench yielded crucial data, including electric power, generated voltage, generator speed, and power consumption (simulating the UAV in this case). During the testing campaign, the variation in the main physical quantities involved in the command and control of the hybrid propulsion system was registered and analyzed. A total power of 700 W was obtained during the tests, which is the maximum that can be registered for maintaining a power of 25 V.

Multi-Rotor UAVs in Crowd Management Systems: Opportunities and Challenges

Multi-Rotor UAVs in Crowd Management Systems: Opportunities and Challenges

Modeling Power Consumptions for Multirotor UAVs

Modeling Power Consumptions for Multirotor UAVs

Co-design of a multirotor UAV with robust control considering handling qualities and motor failure

Over the last few decades, multirotor UAVs have become significantly popular because of their various applications. However, multirotors suffer from poor endurance performance as compared to other aircraft configurations with lifting surfaces. This limitation can be addressed by improving the technology of components or by developing design optimization approaches at the vehicle level. This paper presents a co-design approach for the multirotor structure and propulsive system to improve the vehicle's energetic efficiency while respecting dynamic performance requirements. For this purpose, the approach uses a bi-level formulation to optimize the design and control concurrently. The methodology offers the possibility to activate or not a passive fault tolerant strategy in the controller synthesis to be tolerant to single rotor failure. In contrast to conventional design approaches that sequentially design each part, the co-design approach leads to a better optimal solution by considering the interactions and couplings between design and control. With the proposed co-design approach, the results show the soundness of the proposed design methodology and a significant reduction in the consumed energy compared to a reference non-optimal design while maintaining the same requirements in terms of dynamic performance.

Eagle-inspired manipulator with adaptive grasping and collapsible mechanism and modular DOF for UAV operations

This paper presents an eagle-inspired manipulator designed to enhance the efficiency of medium and large multi-rotor UAVs during contact operations such as picking, obstacle cleaning, and grasping. Drawing inspiration from the skeleton structure and motion law of an eagle’s leg, we propose a prototype design of a large load, wide range of movement, multiple DOF, and collapsible manipulator. The main structure of the manipulator consists of a planetary reducer and a coupled parallel linkage mechanism, which enables it to have greater payload capacity while also increasing its range of motion. The grasping mechanism is based on the motion law of an eagle’s claw, which effectively increases the contact area with targets. To further enhance the DOF of the grasping mechanism, we have designed an ankle mechanism that utilizes a pair of double helical telescopic mechanisms to constrain the DOF of the universal joint, connecting the grasping mechanism to the main structure of the manipulator. Regarding the comparison with existing techniques, our eagle-inspired manipulator has several advantages over previous designs. On one hand, the grasp planning strategy, which is inspired by the motion law of an eagle’s claw, can achieve more reliable and accurate grasping than existing techniques. On the other hand, the manipulator’s collapsible design facilitates easier transportation and storage while maintaining its wide range of motion. What’s more, the modular DOF design allows for greater flexibility in adapting to different payloads and operating environments when compared to existing technologies. We outline the development process of this manipulator, including kinematic modeling and control. The ability of the manipulator system is tested, and flight test experiments are conducted on a UAV carrying the manipulator to demonstrate its practicality and effectiveness.

Comparative Evaluation of Investigation Methods for Estimating the Load-Dependent State of Charge and End of Discharge of a Multirotor UAV Battery

Comparative Evaluation of Investigation Methods for Estimating the Load-Dependent State of Charge and End of Discharge of a Multirotor UAV Battery

Conceptual design for a multi-rotor UAV based on variable paddle pitch

Conceptual design for a multi-rotor UAV based on variable paddle pitch

Relative Localization within a Quadcopter Unmanned Aerial Vehicle Swarm Based on Airborne Monocular Vision

Swarming is one of the important trends in the development of small multi-rotor UAVs. The stable operation of UAV swarms and air-to-ground cooperative operations depend on precise relative position information within the swarm. Existing relative localization solutions mainly rely on passively received external information or expensive and complex sensors, which are not applicable to the application scenarios of small-rotor UAV swarms. Therefore, we develop a relative localization solution based on airborne monocular sensing data to directly realize real-time relative localization among UAVs. First, we apply the lightweight YOLOv8-pose target detection algorithm to realize the real-time detection of quadcopter UAVs and their rotor motors. Then, to improve the computational efficiency, we make full use of the geometric properties of UAVs to derive a more adaptable algorithm for solving the P3P problem. In order to solve the multi-solution problem when less than four motors are detected, we analytically propose a positive solution determination scheme based on reasonable attitude information. We also introduce the maximum weight of the motor-detection confidence into the calculation of relative localization position to further improve the accuracy. Finally, we conducted simulations and practical experiments on an experimental UAV. The experimental results verify the feasibility of the proposed scheme, in which the performance of the core algorithm is significantly improved over the classical algorithm. Our research provides viable solutions to free UAV swarms from external information dependence, apply them to complex environments, improve autonomous collaboration, and reduce costs.

Feasibility study and development analysis of fully actuated multi-rotor UAVs

Fully actuated multi-rotor UAVs have gone through development in the last decades. This article collects studies on different UAV modelling design and feedback control to prove the feasibility of its full actuation. First, the structure design and model construction of fully actuated multi-rotor UAV are discussed and analyzed. Then, the types of fully actuated multi-rotor are classified and analyzed in combination with relevant papers in recent years. Then, the feedback control method is analyzed on the basis of mathematical modeling. Finally, he feasibility of design and control of fully driven UAV has been confirmed, and the future development trend is expected.

In-Ground-Effect Disturbance-Rejection Altitude Control for Multi-Rotor UAVs

In-Ground-Effect Disturbance-Rejection Altitude Control for Multi-Rotor UAVs

Aerial Torsional Work Utilizing a Multirotor UAV with Add-on Thrust Vectoring Device

Aerial manipulation aims to combine the versatility and the agility of aerial platforms with the manipulation capabilities of robotic arms. Their fast deployment allows for their implementation in maintenance tasks and support during disaster situations. However, the under-actuated nature of multirotor UAVs limits the magnitude and direction of the forces an aerial vehicle can safely exert during manipulation tasks. In this paper, the problems associated with UAVs and torsional tasks constraints regarding valve turning are addressed. An add-on thrust vectoring device which enhances manipulation options available to a conventional multirotor UAV is developed and described. The proposed system allows for a partial decoupling of the attitude and velocity vector of a multirotor. This permits stable translational flight and higher torque capabilities for torsional tasks. The separation of attitude and the velocity vector that allows for the design of a passive mechanism for valve operation is presented in this paper as well. The experimental results illustrate the forces and torques that can be generated in the evaluated operation modes.