Title
Compliant Manipulation of Free-Floating Objects
Abstract
Compliant motions allow alignment of workpieces using naturally occurring interaction forces. However, free-floating objects do not have a fixed base to absorb the reaction forces caused by the interactions. Consequently, if the interaction forces are too high, objects can gain momentum and move away after contact. This paper proposes an approach based on direct force control for compliant manipulation of free-floating objects. The objective of the controller is to minimize the interaction forces while maintaining the contact. The proposed approach achieves this by maintaining small constant force along the motion direction and an apparent reduction of manipulator inertia along remaining Degrees of Freedom (DOF). Simulation results emphasize the importance of relative inertia of the robotic manipulator with respect to the free-floating object. The experiments were performed with KUKA LWR4+ manipulator arm and a two-dimensional micro-gravity emulator (object floating on an air bed), which was developed in-house. It was verified that the proposed control law is capable of controlling the interaction forces and aligning the tools without pushing the object away. We conclude that direct force control works better with a free-floating object than implicit force control algorithms, such as impedance control.
Year
DOI
Venue
2018
10.1109/ICRA.2018.8462889
2018 IEEE International Conference on Robotics and Automation (ICRA)
Keywords
Field
DocType
interaction forces,direct force control,implicit force control algorithms,compliant manipulation,free-floating objects,compliant motions,reaction forces,constant force,manipulator inertia,KUKA LWR4+ manipulator arm
Control theory,Control theory,Manipulator,Motion direction,Electrical impedance,Impedance control,Momentum,Inertia,Engineering,Interaction forces
Conference
ISSN
ISBN
Citations 
1050-4729
978-1-5386-3082-2
1
PageRank 
References 
Authors
0.43
0
3
Name
Order
Citations
PageRank
Shikha Sharma110.43
Markku Suomalainen212.80
V. Kyrki365261.79