Publication
Automated off-line generation of stable variable impedance controllers according to performance specifications
Journal Article (2022)
Journal
IEEE Robotics and Automation Letters
Pages
5874-5881
Volume
7
Number
3
Doc link
https://doi.org/10.1109/LRA.2022.3160593
File
Abstract
In this paper, we propose a novel methodology to off-line generate stable Variable Impedance Controllers for any parameter modulation law depending on exogenous signals to the robot, as e.g. the exerted force by the human in a collaborative task. The aim is to find the optimal controller according to a desired trade-off between accuracy and control effort. Each controller is formulated as a polytopic Linear Parameter Varying system consisting on a set of vertex system at the limit operation points. Then, the stability and operating properties can be assessed through Linear Matrix Inequalities, from which an optimality index can be obtained. This index is used by a genetic optimisation algorithm to iteratively generate new controller solutions towards the best one. To exemplify our method, we choose a case study of modulation laws for tasks that require a physical interaction between human and robot, and evaluate generated solutions for different trade-offs on a object handover scenario using a 7-DoF WAM robotic manipulator.
Categories
control nonlinearities, manipulators.
Author keywords
Physical Human-Robot Interaction, Compliance and Impedance Control, Linear Parameter Varying (LPV), Optimization and Optimal Control
Scientific reference
A. San-Miguel, G. Alenyà and V. Puig. Automated off-line generation of stable variable impedance controllers according to performance specifications. IEEE Robotics and Automation Letters, 7(3): 5874-5881, 2022, to appear.
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