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Digital archive of theses discussed at the University of Pisa

 

Thesis etd-09172012-171953


Thesis type
Tesi di laurea specialistica
Author
BALLETTI, LEONARDO
URN
etd-09172012-171953
Thesis title
Stiffness Control in Robotic Assembly Tasks
Department
INGEGNERIA
Course of study
INGEGNERIA DELLA AUTOMAZIONE
Supervisors
relatore Prof. Bicchi, Antonio
controrelatore Prof. Gabiccini, Marco
relatore Grioli, Giorgio
relatore Ing. Catalano, Manuel Giuseppe
relatore Garabini, Manolo
Keywords
  • Assembly tasks
  • Impedance Control
  • Insertion depth
  • Interaction Control
  • Peg in Hole
  • Robotic Assembly
  • Stiffness Selection
  • VSA
Graduation session start date
05/10/2012
Availability
Full
Summary
The peg in hole problem has been heavily studied in literature as a simple model to analyze assembly scenarios. Due to advances in robotic hardware and research on robots which are safe to humans, many of the models and simplifications present in literature don't apply anymore or present poor approximations for modern robots with impedance controllers. In the following work the problem of a peg-in-hole insertion with a impedance controlled robot will be tackled, and simple rules to choose optimal cartesian stiffnesses are presented. The same rules are then applied to solve the problem of optimizing stiffnesses for a VSA robot, where a desired cartesian stiffness cannot generally be obtained. A method to chose weights for the simple weighted minimization of the distance between the desired and obtained cartesian stiffnesses is then proposed, and the results of both approaches are compared by using a robot with deboupled joint stiffness control. Lastly, results of a bimanual insertion using a real VSA robot are proposed.
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