How ornithopters can perch autonomously on a branch

Abstract

Flapping wings produce lift and thrust in bio-inspired aerial robots, leading to quiet, safe and efficient flight. However, to extend their application scope, these robots must perch and land, a feat widely demonstrated by birds. Despite recent progress, flapping-wing vehicles, or ornithopters, are to this day unable to stop their flight. In this paper, we present a process to autonomously land an ornithopter on a branch. This method describes the joint operation of a pitch-yaw-altitude flapping flight controller, an optical close-range correction system and a bistable claw appendage design that can grasp a branch within 25 milliseconds and re-open. We validate this method with a 700 g robot and demonstrate the first autonomous perching flight of a flapping-wing robot on a branch, a result replicated with a second robot. This work paves the way towards the application of flapping-wing robots for long-range missions, bird observation, manipulation, and outdoor flight.

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

“…The robot needs to perch before the manipulation task which was studied in different research work (please visit ref. [8]) and that is not in the scope of this paper. The video of the flight is presented as supplementary material for the article on the journal website.

Figure 10. The folded configuration of the dual-arm for shifting backward the center of mass of the robot.

Figure 11. The axis (a) position of the robot in forward flight, reference 1.75 m, error 29 cm, and (b) velocity of the robot.

Figure 12. The 3D trajectory of the flight of the robot, carrying the dual-arm manipulator on top.

Figure 13. The snapshots of flight with the manipulator and camera in the indoor test bed.

…”

“…The robot needs to perch before the manipulation task which was studied in different research work (please visit ref. [8]) and that is not in the scope of this paper. The video of the flight is presented as supplementary material for the article on the journal website.…”

“…Launch and controlled flight have been studied in previous works [6, 7] and perching in ref. [8]. Stabilization after perching was also covered for this particular concept in literature [9, 10].…”

Electrically active smart adhesive for a perching-and-takeoff robot

“…Moreover, unfriendly contact adaptability on perching surfaces and subsequent rebounds triggered by landing impact can sabotage the grasping/attachment ability, inducing perching failure ( 10 ). Furthermore, perching-and-takeoff sensing ability is also lacking ( 6 – 11 , 13 – 17 , 21 – 25 ), restricting the robots from passively perching on prearranged static or quasi-static surfaces within the range of UAV operator rather than automatically perching on a long-distance moving target. Overall, recent progress in promoting the development of perching robots with traditional rigid robot designing theory (e.g., ingenious rigid mechanisms and control algorithms) remains outweighed by plentiful trade-offs in landing impact, contact adaptability, anti-rebound, grasping-releasing (attachment-detachment) ability, perching-and-takeoff sensing, and manufacturing complexity.…”

“…Numerous existing aerial robots (especially with the weight on the magnitude of kilograms)-mimicking the "wrapping" (6), "grasping" (7)(8)(9)(10)(11)(12), and "hooking" (13) behaviors of flying creatures or attachment style (14)(15)(16)(17) of gecko and octopus-perched on arborization structures, surfaces of buildings, or other specific surfaces. However, the abovementioned approaches generally based on complicated rigid design theory (e.g., using mechanisms, motor/ pump, and grasping and locking devices), while promising on static/quasi-static perching surfaces, still seriously haunt UAVs' reversible perching on moving targets due to numerous inherent shortcomings.…”