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Tesi etd-04082011-160356


Thesis type
Tesi di dottorato di ricerca
Author
GRIOLI, GIORGIO
URN
etd-04082011-160356
Title
Identification for Control of Variable Impedance Actuators
Settore scientifico disciplinare
ING-INF/04
Corso di studi
AUTOMATICA, ROBOTICA E BIOINGEGNERIA
Commissione
tutor Prof. Bicchi, Antonio
Parole chiave
  • Variable Impedance Actuators
  • Robotics
  • Physical Human-Robot Interaction
Data inizio appello
14/06/2011;
Consultabilità
completa
Riassunto analitico
Development of Variable Impedance Actuators (VIA) is a recent evolution in robotics to face hallenges as adaptability to the environment, energy saving, safety and robustness. VIA allow to change the impedance of the limbs of a robot using physical elastic and dissipative elements rather than through traditional Impedance Control.<br>This leads to the problem of controlling a VIA, one important aspect of this problem lies in the absence of sensors able to measure on-line the mechanical impedance of a system. This thesis deals with the problem of impedance parameters observation in a VIA robot. This in order to develop an instrument to be used in implementing real closed-loop control of impedance of a VIA. After an introduction to VIA and traditional impedance measurement techniques, we follow an innovative approach to derive an observer able to estimate in real-time the impedance of a VIA.<br>In particular three observers are presented: a nonparametric stiffness observer, a parametric stiffness observer, and an impedance observer able to estimate either non-linear time-varying stiffness, as long as linear damping and inertia coefficients. Derivation of the algorithms is shown and both simulation and experimental results<br>are presented to support the thesis.
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