Title :
Passive impedance control of a multi-DOF VSA-CubeBot manipulator
Author :
Mancini, Michele ; Grioli, Giorgio ; Catalano, Manuel G. ; Garabini, Manolo ; Bonomo, Fabio ; Bicchi, Antonio
Author_Institution :
Centro Int. di Ricerca “E. Piaggio”, Univ. of Pisa, Pisa, Italy
Abstract :
This work presents an example of the application of passive impedance control of a variable stiffness manipulator, which shows the actual benefits of variable stiffness in rejecting disturbances without resorting to the closure of a high level feedback loop. In the experiment a 4-DOF manipulator arm, built with the VSA-CubeBot platform, is controlled to hold a pen and draw a circle on an uneven surface. The control is designed calculating joint and stiffness trajectories with a Cartesian approach to the problem, thus designing the optimal workspace stiffness at first. Then, the joint stiffness yielding the closest workspace stiffness is searched for. Experimental results are reported, which agree with the theoretical outcomes, showing that the sub-optimal joints stiffness settings allow the arm to follow the circular trajectory on the uneven surface at best.
Keywords :
control system synthesis; electric impedance; end effectors; feedback; humanoid robots; optimal control; trajectory control; 4-DOF manipulator arm; Cartesian approach; circle drawing; circular trajectory; controller design; degrees-of-freedom; disturbance rejection; feedback loop; joint stiffness trajectories; multiDOF VSA-CubeBot manipulator; optimal workspace stiffness design; passive impedance control; pen holding; suboptimal joint stiffness; uneven surface; variable stiffness manipulator; Actuators; Impedance; Joints; Manipulators; Sea surface; Trajectory; Actuators; Humanoid; Modular Robots; Multi DOF Robots; Performance; Physical Human-Robot Interaction; Robot; Variable Stiffness Mechanisms; Workspace Stiffness;
Conference_Titel :
Robotics and Automation (ICRA), 2012 IEEE International Conference on
Conference_Location :
Saint Paul, MN
Print_ISBN :
978-1-4673-1403-9
Electronic_ISBN :
1050-4729
DOI :
10.1109/ICRA.2012.6225082