###### Abstract  
UAVs are one of the fastest types of robots that can be deployed in a remote environment. Unfortunately, they have a limited flight time and therefore may need to stop occasionally in an unknown, uncontrolled area. However, conventional UAVs require flat and stationary surfaces for a safe landing and take-off. Some studies on adaptive landing approach for UAVs can be found in the past, but adaptive take-off from non-flat surfaces has not been discussed for the most part, yet. In this work, we discuss the problems associated with a conventional UAV take-off from non-flat surfaces and provide a novel approach for UAV take-off from a sloped or rocking surface. We also discuss the design of a novel multitasking three-arm aerial manipulator system with parallel link mechanism and achieve the above-mentioned task. With experiments, we show that the system can provide stability for a UAV landing on a rocking surface that allows for a safe take-off. aerial manipulator; adaptive landing; adaptive take-off; aerial robotics; multitasking UAV +
Footnote †: journal: Applied Sciences  
**Citation:** [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] A Versatile Aerial Manipulator Design and Realization of UAV Take-Off from a Rocking Unstable Surface. _Applid_  
Received: 2 September 2021  
Accepted: 27 September 2021  
Published: 1 October 2021  
**Publisher's Note:** MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. **C Copyright:** 2021 by the authors. License MDP, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ([[https://creativecommons.org/licenses/by/4.0/](https://creativecommons.org/licenses/by/4.0/)]([https://creativecommons.org/licenses/by/4.0/](https://creativecommons.org/licenses/by/4.0/))). **1. Introduction**  
UAVs are a very suitable candidate when it comes to search-and-rescue operations using robots. Their capability to hover and maneuver in the skies allows them to receive ground information from high vantage points. This is shown in studies such as [1, 2], concentrating on employing UAVs to map the terrain using camera images after a disaster. UAVs can not only fly and collect photographs, but they can also execute aerial manipulation, given the proper on-board equipment. Research like [3] have presented a framework for valve turning employing a UAV equipped with twin manipulators. Similarly, Ref. [4] focuses on producing large force and moment exertion while employing a UAV to clear obstructions using manipulation by pushing. However, a UAV's payload always limits its potential flying time. Because there is a limit on the size and weight of batteries that can be carried, effective flight management is required as well. Docking or landing a UAV is a preferable option rather than continually hovering in mid-air to extend the work time when the UAV is idle while deploying it across long distances. The work in [5] provides a mechanism to perch a UAV on a farm post using a manipulator mounted on the bottom part of the UAV. However, the work in [6] proposes a bio-inspired multi-modal UAV that flies, perches, and climbs on external surfaces such as concrete or stucco walls. Our previous work in [7], describes the development of a gripper mounted on the top part of a UAV to dock the UAV on pipes. Furthermore, similar to the water sampling in [8], other data collection activities, such as soil samples, may be conducted while the UAV is landed on a surface. Many previous studies have concentrated on developing an autonomous landing system for UAVs that would be suited for carrying out the aforementioned tasks. Manually landing a UAV in an unfamiliar location is a time-consuming and difficult process due to environmental clutter. Furthermore, manually landing through remote tele-operation necessitates the use of a qualified operator. Studies such as [9, 10], focus on autonomously landing a UAV using camera information.