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Singularity analysis of closed-loop inverse kinematics algorithms with respect to manipulator geometric uncertainties
KTH, School of Computer Science and Communication (CSC), Computer Vision and Active Perception, CVAP.ORCID iD: 0000-0002-4032-4830
KTH, School of Computer Science and Communication (CSC), Computer Vision and Active Perception, CVAP.ORCID iD: 0000-0002-7714-928X
2014 (English)Manuscript (preprint) (Other academic)
Place, publisher, year, edition, pages
2014. Vol. 19, 311-319 p.
National Category
Robotics
Research subject
Computer Science
Identifiers
URN: urn:nbn:se:kth:diva-182901OAI: oai:DiVA.org:kth-182901DiVA: diva2:906225
Conference
The 19th IFAC world congress
Note

QS 2016

Available from: 2016-02-24 Created: 2016-02-24 Last updated: 2016-02-24Bibliographically approved
In thesis
1. Reactive control and coordination of redundant robotic systems
Open this publication in new window or tab >>Reactive control and coordination of redundant robotic systems
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Redundant robotic systems, in terms of manipulators with one or twoarms, mobile manipulators, and multi-agent systems, have received an in-creasing amount of attention in recent years. In this thesis we describe severalways to improve robotic system performance by exploiting the redundancy.

As the robot workspace becomes increasingly dynamic, it is common towork with imperfect geometric models of the robots or its workspace. Inorder to control the robot in a robust way in the presence of geometric uncer-tainties, we propose to assess the stability of our controller with respect to acertain task by deriving bounds on the geometric uncertainties. Preliminaryexperimental results support the fact that stability is ensured if the proposedbounds on the geometric uncertainties are fulfilled.

As a non-contact measurement, computer vision could provide rich infor-mation for robot control. We introduce a two step method that transformsthe position-based visual servoing problem into a quadratic optimization prob-lem with linear constraints. This method is optimal in terms of minimizinggeodesic distance and allows us to integrate constraints, e.g. visibility con-straints, in a natural way.

In the case of a single robot with redundant degrees of freedom, we canspecify a family of complex robotic tasks using constraint based programming(CBP). CBP allows us to represent robotic tasks with a set of equality andinequality constraints. Using these constraints we can formulate quadraticprogramming problems that exploit the redundancy of the robot and itera-tively resolve the trade-off between the different constraints. For example, wecould improve the velocity or force transmission ratios along a task-dependent direction using the priorities between different constraints in real time.

Using the reactiveness of CBP, we formulated and implemented a dual-armpan cleaning task. If we mount a dual-arm robot on a mobile base, we proposeto use a virtual kinematic chain to specify the coordination between the mobilebase and two arms. Using the modularity of the CBP, we can integrate themobility and dual-arm manipulation by adding coordination constraints intoan optimization problem where dual-arm manipulation constraints are alreadyspecified. We also found that the reactiveness and modularity of the CBPapproach is important in the context of teleoperation. Inspired by the 3Ddesign community, we proposed a teleoperation interface control mode thatis identical to the ones being used to locally navigate the virtual viewpoint ofmost Computer Aided Design (CAD) softwares.

In the case of multiple robots, we combine ideas from multi-agent coopera-tive coverage control, with problem formulations from the resource allocationfield, to create a distributed convergent approach to the resource positioningproblem.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2016. xii, 62 p.
Series
TRITA-CSC-A, ISSN 1653-5723 ; 2016:05
Keyword
reactive control, dual-arm manipulation, mobile manipulation, ambulance positioning.
National Category
Robotics Control Engineering Computer Systems
Research subject
Computer Science
Identifiers
urn:nbn:se:kth:diva-182680 (URN)978-91-7595-870-5 (ISBN)
Public defence
2016-03-22, F3, Lindstedtsvägen 26, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20160224

Available from: 2016-02-24 Created: 2016-02-22 Last updated: 2016-02-24Bibliographically approved

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