Design and Control of a Fast and Precise Aerial Manipulator

This report describes the work involved during a six months project carried on at Autonomous Systems Lab of ETH Zurich. The goal of this project is to develop a fast and precise robotic manipulator for aerial interaction. The omnidirectional MAV from ASL researchers is the aerial platform on which the manipulator will have to be mounted. First stage of the project involves an intensive literature research aimed at identifying those ideas and solutions which could fit our project requirements. From this review, the 3 DOF Delta parallel manipulator has been selected: lightness, reduced moving mass, precision and stiffness are the main advantages of this robotic manipulator. Subsequently, an extensive work has been focused on the study of robot kinematics and dynamics. A non linear optimization problem has been formulated to solve the synthesis task of geometric parameters by means of a so called genetic algorithm. Most of Delta mechanical components have been designed using CAD software and machined by 3D printing technology, while just few elements have been obtained by third party suppliers. Finite element analysis has been exploited for mechanical validation. Also system control has been taken into account: an inverse kinematics-base approach has been developed aimed at compensating for aerial platform pose errors and thus maintain end-effector position to millimetric accuracy. Lastly, real field tests have been run to evaluate system performances, data have been collected and presented to show positive and negative aspects of the designed system. Final conclusions about possible future improvements is the last contribution provided by this work.