Compliant Manipulation of Free-Floating Objects

Shikha Sharma, Markku Suomalainen, Ville Kyrki

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

1 Citation (Scopus)
124 Downloads (Pure)


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.
Original languageEnglish
Title of host publicationProceedings of the 2018 IEEE International Conference on Robotics and Automation, ICRA 2018
Number of pages8
ISBN (Electronic)978-1-5386-3081-5
Publication statusPublished - 22 May 2018
MoE publication typeA4 Article in a conference publication
EventIEEE International Conference on Robotics and Automation - Brisbane, Australia
Duration: 21 May 201825 May 2018

Publication series

NameIEEE International Conference on Robotics and Automation
ISSN (Print)2152-4092
ISSN (Electronic)2379-9552


ConferenceIEEE International Conference on Robotics and Automation
Abbreviated titleICRA


  • Manipulators
  • Force
  • Force control
  • Impedance
  • Damping
  • Aerospace electronics


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