A 79.7g Manipulator Prototype for E-Flap Robot: A Plucking-Leaf Application

Abstract

The manipulation capabilities of flapping-wing flying robots (FWFRs) is a problem barely studied. This is a direct consequence of the load-carrying capacity limitation of the flapping-wing robots. Ornithopters will improve the existent multirotor unmanned aerial vehicles (UAVs) since they could perform longer missions and offer a safe interaction in proximity to humans. This technology also opens the possibility to perch in some trees and perform tasks such as obtaining samples from nature, enabling biologists to collect samples in remote places, or assisting people in rescue missions by carrying medicines or first-aid kits. This paper presents a very lightweight manipulator (79.7g) prototype to be mounted on an ornithopter. The distribution of the mass on the flapping-wing robot is sensitive and an extra lumped mass far from the center-of-mass (CoM) of the robot deteriorates the flight stability. A configuration was proposed to avoid changing the CoM. Flight experiments show that adding the arm to the robot only moved the CoM 6mm and the performance of the flight with the manipulator has been satisfactory. Plucking leaf is chosen as an application to the designed system and several experimental tests confirmed successful sampling of leaves by the prototype.

A 94.1 g scissors-type dual-arm cooperative manipulator for plant sampling by an ornithopter using a vision detection system

“…The main contribution of the work is extending the manipulator from a single arm to a dual arm in comparison with ref. [6] and adding a vision system for the detection of the target. The previous sampling mechanism worked with a plucking method that could damage a part of the sample; however, this mechanism holds the sample with one arm and cuts the stem with another arm without exerting unnecessary force on the sample.…”

“…The presented work in this paper is inspired by ref. [6], which described a sampling scheme with a single arm and a gripper without vision detection (79.7 g); hence, the position of the leaf must have been provided by the user. In this work, we concentrated on usability and added two main novelties to automatize sampling and improve performance: (1) a dual-arm manipulator with a scissors-type arm and a gripper and (2) a vision detection system that provides the position of the stem to the arm for sampling (Fig.…”

“…Multirotor UAVs were employed for this task, as presented in the literature; however, by ornithopters, there is no report on sampling or intervention so far except for ref. [6]. The global picture for the operation of the flapping-wing robot includes several phases: launching, controlled flight, perching, stabilization of bird after perching, manipulation, and finally, take-off again (see Fig.…”

“…The manipulation has been investigated in detail in the current work, and proof of flight capability has been presented briefly since that is a critical point. Launch and controlled flight have been studied in previous works [6, 7] and perching in ref. [8].…”

“…In terms of weight, moving from one to two arms and also adding a scissors-type manipulator added only 14.4 g to the system in comparison with ref. [6].…”