Aerial manipulation: physical interaction with the environment by using a robotic manipulator attached to the airframe of an aerial robot. In the future one can expect that aerial manipulation will greatly extend the range of possible applications for mobile robotics, especially multirotor UAVs. This can range from inspection and maintenance of previously hard to reach pieces of infrastructure, to search and rescue applications. What kind of manipulator is attached to what position of the airframe is a key point in accomplishing the aerial robot’s function and in the past, various aerial manipulation solutions have been proposed. This review paper gives an overview of the literature on aerial manipulation that have been proposed so far and classifies them by configuration of the workspace and function.

This paper describes the concept, design and realization of a novel manipulator system for a multirotor aerial robot. The proposed manipulator system consists of three robotic arms attached to a multirotor frame. To overcome the limited payload capabilities in multirotor aerial platforms, the same set of on-board manipulators are used to realize various tasks, primarily the manipulation or grasping of objects of various sizes. Furthermore, they can provide aid in complex navigation tasks by doing physical, contact-based obstacle avoidance and are able to act as adaptive landing gear in uneven terrain. The design requirements and the analysis to realize these tasks is discussed. The proposal is supported with the successful demonstration of these tasks using the aerial multi manipulator system in an outdoor environment. GRAPHICAL ABSTRACT

We have proposed airborne docking using two multi-rotor aerial robots. This paper presents a transport multi-rotor UAV with winch mechanism and a small multi-rotor with onboard locolization and mobile manipulation system. The winch mechanism enables the UAV to lower and raise a bar to transport another UAV attached to it. The airborne docking method used in our work is chosen in order to avoid the effect of downwash generated by the multi-rotors. With experiments we have verified the possibility of airborne docking, and evaluated how it influences the transport multi-rotor UAV as the load is changed, using the IMU data of UAV.

We herein propose a long-reach aerial manipula-tion to allow the manipulation of objects several meters away from an unmanned aerial vehicle (UAV). The system consists of a multirotor platform with winch mechanism and wire-suspended gripper module equipped with a camera and swing-suppression device. The winch controls the distance of the wire-suspended device from the UAV. To stabilize the device suspended from the UAV by two wires, we developed a swing-suppression device using an IMU and ducted fans. Through experiments, we verified effectiveness of the swing-suppression system; that is, it successfully stabilized the wire-suspended device within a distance of 3.5 m from the UAV. Furthermore, we performed a pick-and-place task using a gripper that was lowered from the UAV by 3 m.

We describe the concept, design and implementation of a unique manipulator system for a multirotor aerial vehicle. The proposed manipulator system consists of three robotic arms attached to a multirotor airframe with the objective to provide the ability to manipulate single or multiple objects as well as aid in complex navigation tasks by doing contact based obstacle avoidance and acting as adaptive landing gear in uneven terrain. In this paper we primarily focus on the description and experimentation of one of the tasks achievable by the proposed aerial multi-manipulator system: landing a multirotor aerial vehicle on an uneven surface. Deploying the on-board manipulator as landing gears reduces the hardware carried by the vehicle while additionally providing the ability to land in unstructured and commonly difficult to land terrain.

Quadcopter is a type of unmanned aerial vehicle (UAV) that offers excellent flight ability albeit with relatively low payload. Despite its widespread use for transportation, improving its robustness against disturbances and carrying capacity has been challenging. Thus, this study proposed a cable suspended multi-UAVs transportation system with a controller and disturbance observer that is highly robust against disturbances. The primary objective of this study is to design a robust controller and disturbance observer by considering the effect of the cable-suspended payload on the UAV as a part of the disturbance. Consequently, reducing the complexity of the problem and allowing a range of algorithms to be used. A controller and disturbance observer are designed based on backstepping control and the extended state of the model, respectively, to control the flight of the multiple UAVs while carrying a cable-suspended payload. Further, to exploit the agility of quadcopters and avoid obstacles, a virtual structure based leader-follower dynamic formation scheme is introduced to change the formation geometry during the flight with cable suspended payload. This scheme does not make any assumption regarding the status of cable tension during the flight and thus no feedback measurement is required from payload. Moreover, the stability analysis of the proposed system is verified theoretically based on Lyapunov stability and through indoor experiments.