EU Robotics Forum
Session Title:
Control and Application of Cable-Driven Parallel Robots
time of workshop:
20 March, 08:30 o´clock
Organisers:
Andreas POTT, Fraunhofer IPA, email: Andreas.Pott@ipa.fraunhofer.de
Tobias BRUCKMANN, Duisburg-Essen University, email: tobias.bruckmann@uni-due.de
Jean-Pierre MERLET, INRIA Sophia-Antipolis, email: Jean-Pierre.Merlet@inria.fr
Motivation and objective:
In the recent years, cable robots received lots of attention due to their advantages over serial kinematics and conventional parallel kinematics. On the one side, cable robots inherit the properties of all parallel kinematic robots as for example high structural stiffness, payload and good precision. On the other side, they outperform conventional parallel kinematics with regards to flexibility, workspace and speed, because the cables allow for ultra-light weight constructions in nearly arbitrary large areas.
Last September, the First International Conference on Cable-Driven Parallel Robots (CableCon 2012) took place at Fraunhofer IPA in Stuttgart. During the conference it became apparent, that control is one of the most important issues.
Problem statement:
- Cable can only transmit pull forces
- Strategies for dealing with over- and under-constrained robots
- Stability and design of force controllers
- Implementation of complex algorithms on real-time controllers
In this workshop, the control of cable robots will be examined under different point of views:
- Real-Time determination of feasible cable force distributions as set point values for cable force control
- Internal force control: Control both, position and forces in redundant robots
- External force control for assembly or applications with process forces like grinding
- Characteristic of the control of under constrained robots
The objective of the session is to exchange practical experiences and discuss how to adapt existing approaches to cable robots. It is known for years that problem of computing cable force distributions is related to multi-fingered grasping. Anyway, little results have been exchanged between the two communities.
Approach:
The workshop starts with the presentation of the state of the art and problem statement by experts of the cable robot community. Subsequently, in an open discussion ideas for solving the addressed problems will be searched. The goal is to profit from the participant’s different robotic background and to adapt existing control strategies on cable robots.
Agenda of the workshop:
8:30 – 8:40: Introduction to the workshop
8:40 – 9:50: Presentation of the speakers (each 20min)
9:50 – 10:30: Open Discussion with the participants
Speakers:
Some of the proposed speakers have built several prototypes of cable-driven parallel robots for various industrial and medical projects and are involved in the FP 7 European Project CableBOT (Parallel Cable Robotics for Improving Maintenance and Logistics of Large-Scale Products) that has started at the end of 2011. The proposed talks will mix practical implementation and use, lessons learned from this corpus of experiments and issues that must be addressed.
- C. Baradat (Tecnalia Spain): Application of cable-driven parallel robots in FP7 CableBOT projects
- M. Gouttefarde (LIRMM): Control of Giant Cable Robots: The ANR CoGiRo project
- T. Bruckmann / C. Reichert (University Duisburg-Essen): Real-Time determination of set point cable force distributions
- D. Surdilovic (Fraunhofer IPK): Impedance control for cable robots
- A. Pott (Fraunhofer IPA): Practice Report of the Implementation of cable force control on a redundant cable robot
- Open discussion on cable robot, control and application moderated by J.-P. Merlet (INRIA Sophia-Antipolis)
How can participants contribute to, and prepare for, the workshop?
The participants should have a basic knowledge about kinematic and control. We ask for contributions regarding
- theoretical and practical approaches for control strategies of redundant parallel robots
- experiences in force control with classical industrial robots
- force control in multi-fingered robotic grasping
- application ideas for cable robot
Further information:
- http://www.ipa.fraunhofer.de/Parallele_Seilroboter.597.0.html?&L=2
Planned follow-up:
The presentations of the speakers will be freely available on the workshop web site. The discussions that will be held during the industrial/application and academic sessions will be summarized in a prospective report that will be made available on the EUROP and EURON websites.