Forceful Valve Manipulation With Arbitrary Direction by Articulated Aerial Robot Equipped With Thrust Vectoring Apparatus

Abstract

Aerial manipulation is a growing field of research, and multirotors with attached arm manipulator have shown practical utility in contact-based inspection. However, theses coupled platforms limit the pose reachability of the end-effector, which then motivates the development of omni-directional designs for aerial robots. Although the full pose tracking can be achieved by these omni-directional models, the large amount of internal thrust force constrains wrench exertion for forceful manipulation such as valve operation. Thus, in this letter, we harness an articulated aerial robot equipped with thrust vectoring apparatus, which enables not only the omni-directional pose of end-effector, but also the sufficient 6 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula> -of-freedom wrench for valve operation. First, we develop a joint configuration strategy for this articulated model to ensure sufficient torque to turn valves. Then, we present control and motion planning methods for exerting appropriate wrench while following a manipulation trajectory. Comprehensive experiments that involves various valve directions are evaluated in this work, demonstrating the feasibility of our methods to exert forceful wrench. To the best of our knowledge, this letter is the first to achieve the operation of real industrial valve with real torque scale.