Title
Nonlinear oscillations for cyclic movements in variable impedance actuated robotic arms
Abstract
Biologically inspired Variable Impedance Actuators (VIA) offer the capability to execute cyclic and/or explosive multi degree of freedom (DoF) motions efficiently by storing elastic energy. This paper studies the preconditions which allow to induce robust cyclic motions for strongly nonlinear, underactuated multi DoF robotic arms. By experimental observations of human motor control, a simple control law is deduced. This controller achieves intrinsic oscillatory motions by switching the motor position triggered by a joint torque threshold. Using the derived controller, the periodic behavior of the robotic arm is analyzed in simulations. It is found that a modal analysis of the linearized system at the equilibrium point allows to qualitatively predict the periodic behavior of this type of strongly nonlinear systems. The central statement of this paper is that cyclic motions can be induced easily in VIA systems, if the eigenfrequencies and modal damping values of the linearized system are well separated. Validation is given by simulation and experiments, where a human controls a simulated robotic arm, and the developed regulator controls a robotic arm in simulation and experiments.
Year
DOI
Venue
2013
10.1109/ICRA.2013.6630622
Robotics and Automation
Keywords
Field
DocType
biomechanics,damping,manipulators,modal analysis,motion control,nonlinear control systems,position control,DoF motion,VIA,biologically inspired variable impedance actuator,cyclic movement,eigenfrequencies,elastic energy,equilibrium point,human motor control,intrinsic oscillatory motion,joint torque threshold,linearized system,modal analysis,modal damping value,motor position,multiDoF robotic arm,multidegree-of-freedom motion,nonlinear oscillation,periodic behavior,robust cyclic motion,variable impedance actuated robotic arm
Control theory,Robotic arm,Motion control,Nonlinear system,Nonlinear Oscillations,Torque,Control theory,Control engineering,Engineering,Underactuation,Modal analysis
Conference
Volume
Issue
ISSN
2013
1
1050-4729
ISBN
Citations 
PageRank 
978-1-4673-5641-1
6
0.57
References 
Authors
4
3
Name
Order
Citations
PageRank
Dominic Lakatos1478.03
Florian Petit2907.90
Alin Albu-Schaffer32831262.17