Modeling and control of an overactuated aerial vehicle with four tiltable quadrotors attached by means of passive universal joints

We present a novel overactuated aerial vehicle based on four quadrotors connected to an airframe by means of passive universal joints. The proposed architecture allows to independently control the six degrees of freedom of the airframe without having fixed propellers at inefficient configurations or making use of dedicated rotor tilting actuators. After deriving the dynamic equations that describe its motion, we propose a linear control strategy that is able to successfully decouple rotation and translation, relying exclusively on on-board sensors. A prototype is built and preliminary experimental results demonstrate that the concept is feasible.Video: https://youtu.be/9ASP3FyhCJw.This research was supported by the ELKARTEK 2018 program of the Basque Government, grant agreement No. KK-2018/00082

A New Classification and Aerial Manipulation Q-PRR Design

International audienceThis paper presents a new designation and classification of system with UAV and robot manipulator where a new nomenclature is recognized as being the first contribution in the bibliography of design and systems. Several papers deal a problem of manipulation with a different unmanned aerial vehicle, robot arms and also with different naming of their systems, where the difficulty for locate and finding items and a good paper with its title or even by keywords, multirotor equipped with n-DoF robotic arm is the expression among the most widely used to describe that system. Aerial manipulation formula is presented and proved with a large example in the literature

An aerial parallel manipulator with shared compliance

Accessing and interacting with difficult to reach surfaces at various orientations is of interest within a variety of industrial contexts. Thus far, the predominant robotic solution to such a problem has been to leverage the maneuverability of a fully actuated, omnidirectional aerial manipulator. Such an approach, however, requires a specialised system with a high relative degree of complexity, thus reducing platform endurance and real-world applicability. The work here presents a new aerial system composed of a parallel manipulator and conventional, underactuated multirotor flying base to demonstrate interaction with vertical and non-vertical surfaces. Our solution enables compliance to external disturbance on both subsystems, the manipulator and flying base, independently with a goal of improved overall system performance when interacting with surfaces. To achieve this behaviour, an admittance control strategy is implemented on various layers of the flying base's dynamics together with torque limits imposed on the manipulator actuators. Experimental evaluations show that the proposed system is compliant to external perturbations while allowing for differing interaction behaviours as compliance parameters of each subsystem are altered. Such capabilities enable an adjustable form of dexterity in completing sensor installation, inspection and aerial physical interaction tasks. A video of our system interacting with various surfaces can be found here: https://youtu.be/38neGb8-lXg

A review of aerial manipulation of small-scale rotorcraft unmanned robotic systems

Small-scale rotorcraft unmanned robotic systems (SRURSs) are a kind of unmanned rotorcraft with manipulating devices. This review aims to provide an overview on aerial manipulation of SRURSs nowadays and promote relative research in the future. In the past decade, aerial manipulation of SRURSs has attracted the interest of researchers globally. This paper provides a literature review of the last 10 years (2008–2017) on SRURSs, and details achievements and challenges. Firstly, the definition, current state, development, classification, and challenges of SRURSs are introduced. Then, related papers are organized into two topical categories: mechanical structure design, and modeling and control. Following this, research groups involved in SRURS research and their major achievements are summarized and classified in the form of tables. The research groups are introduced in detail from seven parts. Finally, trends and challenges are compiled and presented to serve as a resource for researchers interested in aerial manipulation of SRURSs. The problem, trends, and challenges are described from three aspects. Conclusions of the paper are presented, and the future of SRURSs is discussed to enable further research interests

Proofs of Control of a Quadrotor and a Ground Vehicle Manipulating an Object

This paper focuses on the control of a cooperative system composed of an Unmanned Aerial Vehicle (UAV) and an Unmanned Ground Vehicle (UGV) manipulating an object. The two units are subject to input saturations and collaborate to move the object to a desired pose characterized by its position and inclination. The dynamics are derived using Euler-Lagrange method. A pre-stabilizing control law is proposed where the UGV is tasked to deploy the object to a certain position whereas the UAV adjusts its inclination. In particular, a proportional-derivative control law is proposed for the UGV, and a cascade control approach is used for the UAV, where the inner loop controls the attitude of the UAV and the outer loop stabilizes the inclination of the object. Then, we prove the stability of the points of equilibrium using small gain arguments. To ensure constraints satisfaction at all times, a reference governor unit is added to the pre-stabilizing control scheme. Finally, numerical results combined with experimental results are provided to validate the effectiveness of the proposed control scheme in practice.Comment: 16 pages, 7 figure

6D Pose Task Trajectory Tracking for a Class of 3D Aerial Manipulator From Differential Flatness

In this paper, the dynamics and control of a novel class of aerial manipulator for the purpose of end effector full pose trajectory tracking are investigated. The 6D pose of the end effector is set as a part of the flat output, from which the conditions that the system has the proposed flat output is obtained. The control law for the end effector tracking purpose is designed. The core part of the controller is an almost global controller in the configuration space of the system. From the transformation between the state space and the output space, the tracking control of the end effector in SE (3) is also achieved. The stability of the controlled system is analyzed. A numerical example is presented to demonstrate the theoretical analysis

A Lightweight Modular Continuum Manipulator with IMU-based Force Estimation

Most aerial manipulators use serial rigid-link designs, which results in large forces when initiating contacts during manipulation and could cause flight stability difficulty. This limitation could potentially be improved by the compliance of continuum manipulators. To achieve this goal, we present the novel design of a compact, lightweight, and modular cable-driven continuum manipulator for aerial drones. We then derive a complete modeling framework for its kinematics, statics, and stiffness (compliance). The modeling framework can guide the control and design problems to integrate the manipulator to aerial drones. In addition, thanks to the derived stiffness (compliance) matrix, and using a low-cost IMU sensor to capture deformation angles, we present a simple method to estimate manipulation force at the tip of the manipulator. We report preliminary experimental validations of the hardware prototype, providing insights on its manipulation feasibility. We also report preliminary results of the IMU-based force estimation method.Comment: 12 pages, submitted to ASME Journal of Mechanisms and Robotics 2022, under review. arXiv admin note: substantial text overlap with arXiv:2206.0624

Innovative development of a flying robot with a flexible manipulator for aerial manipulations

This paper presents an innovative development of a flying robot or an aerial robot, with a flexible manipulator, called the Dexterous Aerial Robotic System (DFTS), for aerial manipulations, especially for inspections and reparations of various structures such as wind turbines, power lines and open gas pipelines, decorations and painting of high industrial chimneys and walls of high buildings, as well as transport and delivery of courier shipments, relocation and manipulation of assemblies and units in inaccessible or dangerous environments. The proposed DFTS consists of two independent but interconnected systems or functional units, which have two main separate functions respectively, including a basic carrying function, and a precise positioning and stabilization function. The system with a basic carrying function is actually the main flying system, the un-manned aerial vehicle (UAV); it is remotely controlled and piloted. Meanwhile, the aerial manipulation platform, called the vertical take-off and landing platform VTOL, which is an active flying platform with 6 degrees of freedom (DOF) is used for positioning and stabilization; and it is attached to the UAV via the soft link. With the use of a long soft link, the problems which are caused by the air turbulent flows generated by the UAV are minimized, and the aerial manipulations of objects are safely controlled and operated. The VTOL which is equipped with a grasping mechanism was successfully developed, prototyped and tested. The experimental results showed that, the developed VTOL can self-stabilize with the inclination angle of being up to 8 degrees

Design and Control of Omni-directional aerial robot

학위논문 (석사)-- 서울대학교 대학원 : 기계항공공학부, 2016. 2. 이동준.우리는 비대칭적인 분산된 멀티 로터 배치로 SE(3)에서 fully-actuated한 특성을 가지고 비행과 회전이 동시에 가능하여 일반적인 비행로봇이 가지고 있는 under-actuation한 문제를 극복 할 수 있는 전방향 비행 로봇이라는 새로운 디자인의 비행 로봇을 제안한다. 먼저 우리는 각 로터들 사이의 공기역학적인 간섭을 최소화함과 동시에 최대의 제어 렌치를 생수 할 수 있게 하기 위해 로터 배치의 최적화 작업을 수행한다. 우리는 SE(3)에서 ODAR 시스템의 동역학 모델링을 제시하고 병진운동과 회전운동의 제어 디자인을 진행한다. 우리는 또한 ODAR 시스템을 실제 제작하고 그것의 성능을 검증한다. 기존의 비행로봇과는 완전히 다른 시스템으로서 우리는 ODAR 시스템이 전방향 렌치 생성이 중요한 항공 매니퓰레이터나 가상현실 렌더링 3D 환경구축을 위한 전방향 구동에서의 촬영 성능을 지닐 수 있는 항공 촬영 역할을 수행 할 것으로 믿는다.We propose a novel aerial robot system, Omni-Directional Aerial Robot (ODAR), which is fully-actuated in SE(3) with asymmetrically distributed multiple rotors and can fly and rotate at the same time, thereby, overcoming the well-known under-actuation problem of conventional multi-rotor aerial robots (or simply drones). We first perform optimization of rotor distribution to maximize control wrench generation in SE(3) while minimizing aero-dynamic interference among the rotors. We present dynamics modeling of the ODAR system in SE(3) and simultaneous translation / orientation control design. We also implement a ODAR system and experimentally validate its performance. Being completely different from the conventional drone, we believe this ODAR system would be promising for such applications as aerial manipulation, where omni-directional wrench generation is important, and also as aerial photography, where an ability to taking photos in omni-direction is desired for 3D environment reconstruction for VR scene rendering.1 서론 1 1.1 연구 동기 및 목적 1 1.2 연구 성과 4 2 시스템 디자인 및 제어 설계 6 2.1 시스템 디자인 6 2.2 제어 설계 16 3 시뮬레이션 21 3.1 시뮬레이션 준비 21 3.2 시뮬레이션 결과 24 4 시스템 제작 27 4.1 시스템 제작 준비 27 4.2 시스템 제작 구성품 28 4.3 시스템 제작 통합 34 5 실험 36 5.1 실험 준비 36 5.2 실험 결과 38 5.2.1 원형 궤적 추적 39 5.2.2 3D 영상촬영 모션 42 5.2.3 수직 구동 작업 45 6 결론 49 6.1 결론 49 6.2 향후 과제 50 참고문헌 52 Abstract 57Maste