DTA

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Tesi etd-05142023-200717

Type of thesis
Corso Ordinario Secondo Livello
Author
BOSIO, CARLO
URN
etd-05142023-200717
Title
Robotic Grasping of Rocky Surfaces: Analysis of a Gripper With Microspines for Planetary Exploration
Structure
Cl. Sc. Sperimentali - Ingegneria
Course
INGEGNERIA - INGEGNERIA
Committee
relatore Prof.ssa LASCHI, CECILIA
Presidente Prof. FORESTIERI, ENRICO
Membro Dott.ssa COLLA, VALENTINA
Membro Prof. SOLAZZI, MASSIMILIANO
Membro Prof. DI PASQUALE, FABRIZIO CESARE FILIPPO
Membro Prof. DE SIMONE, ANTONIO
Membro Prof. BUTTAZZO, GIORGIO CARLO
Keywords
  • climbing robot
  • microspines
  • grasping
  • gripper
Exam session start date
21/06/2023;
Availability
parziale
Abstract
Climbing robots represent an excellent solution for environmental exploration and field operations. The ability to achieve secure grasps on rocky surfaces makes these robots particularly interesting for the extreme environments encountered during planetary exploration. In this thesis, a preliminary analysis of a gripper for a climbing robot, ReachBot, is performed. The robot consists of a compact body equipped with extensible booms and grippers attached to their extremities. The gripper grasps on rocky surfaces by leveraging microspines, i.e. small needles that engage on surface asperities. The work carried out for this thesis starts with the elaboration of a mechanical model for the interaction between the gripper and a rock. The model is then used to build a Monte Carlo simulation with the goal of estimating the maximum external wrench the gripper can withstand once the grasp is finalized. The output of the simulation is the limit surface, i.e. the boundary of the admissible (safe) region in the wrench space. The limit surface is fundamental at the grasp planning stage to assess the quality of a potential grasp site. Finally, the insights gained from the simulation are leveraged to choose various design parameters and perform a design iteration for a three finger gripper. The main characteristics of the device are the passive activation through a mechanical trigger and the load sharing mechanism, which is desirable in order to equally preload the gripper fingers.
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