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Show THE UNIVERSITY OF UTAH RESEARCH POSTERS ON THE HILL 2013 SARRUS-BASED PASSIVE MECHANISM FOR ROBOTIC PERCHING K. Beau Freckleton (Jake Abbott, Mark Minor, Michelle Burroughs) Department of Mechanical Engineering University of Utah Sarrus-Based Passive Mechanism for Rotorcraft Perching Jake J. Abbott; Ph.D., Mark A Minor; Ph.D. Michelle Burroughs, K. Beau Freckleton Department of Mechanical Engineering iSS u I III UNIVERSITY Or U T AH u MECHANICAL ENGINEERING Introduction Quad-rotors are helicopter-like trying objects that are designed quick and efficient maneuverability In mtd-flighi These i by lerge-acaie agriculturalists to i coll«cton using humans would bo i expensive The primary objective of this project i mechanism that allow* a quad-rotor to perch from Tud-flaght onto an object and remain perched under elemental a energy consumption il will rely purety upon (he weight of the quad-rotor aa the neceuary force to firmly grasp the branch While perched. r the quad-rotor to recharge Its power source using tolar energy The motivation for Ihe project originated from s need of a i efficient way to learn of mildew growth within a vineyard before ft spread i inspired by the way that birds can sleep while R M l i l tS After further optimization research, 3D Printing technology was I to construct a preliminary prototype out of a rigid plastic material and designed to fit en R C helicopter. The teats found thai the mechanism allowed the helicopter to perch on a cylindrical object end remain upright while on a flat surface However, upon crash testing the mechanism fractured due to design flews Because of Its large height the helicopter Is also prone to lipping under forces such es wind Further r< i perching by lending from flight with the ability to withstand f crashing and provide a powerful resistance to elemental forces Current quad-rotors provide excellent maneuverability and opportunity for data collection in large scale areas such as agriculture, but lack the capability to maintain flight for an extended period of time. This is due primarily to a lack of energy supply, requiring operators to replace the battery source before the quad-rotor completes its designated purpose [1], In this paper, w e introduce a mechanism to enable flying robotic rotorcraft, such as quadrotors and helicopters which utilize vertical take-off and landing, to perch similar to a ' bird. The mechanism is passive, using only the weight of the rotorcraft for actuation. Such a mechanism will dispel the need for multiple batteries by allowing the quadrotor to perch amid its designated flight course, recharge using solar energy, and complete data collection over large scale areas in less time. In previous research to this same end, biomimetic approaches were pursued, resulting in designs that looked similar to the legs and feet of birds. The design in this paper utilizes a Sarrus mechanism to convert rotorcraft weight into perch grip. W e began by designing the mechanism for a range of cylindrical perch sizes. Using MATLAB, w e developed a program to optimize the various mechanism dimensions needed to perch within this range while also maximizing the mechanical advantage of grip force. Using SolidWorks, a 3-dimensional model was created and manufactured with these dimensions. In testing, the mechanism successfully allowed a small RC helicopter to perch on a 4 cm diameter rod with some resistance to external forces. However, in crash tests, the mechanism was unable to withstand certain moment forces and developed large fractures. Further research will focus on decreasing these moment forces'ability to weaken the mechanism while optimizing perching capability. |
