Full-day workshop at the 2017 IFAC World Congress
9 Jul 2017 Toulouse (France)

Rigidity Theory for Multi-agent Systems Meets Parallel Robots: Towards the Discovery of Common Models and Methods

Update: slides of the talks available below!

The goals of this workshop are to explore connections and encourage discussion between two historically distinct communities: the parallel robotics community and the multi-robot community (for what concerns, generally speaking, rigidity-based methods for distributed formation control and localization). Indeed, although these two areas may appear as quite distant, they actually share a strong common underline theme: understanding how pairwise geometrical constraints (e.g., relative distances or angles) can affect the mobility or state (pose) estimation for robotic systems. Moreover, there is a strong analogy between multi-agent systems and parallel robots: each robot of the system can be seen as a passive joint of a virtual mechanical (parallel) architecture and each measurement between two robots as a rigid connection between them, rigid connection whose dimension can vary thanks to a virtual actuator. So it is possible to find virtual parallel robot architectures associated with multi-agent systems.

Rigidity-based multi-robot control/estimation is typically concerned about topics such as: (i) understanding what is the minimum number of edges (of constraints) for ensuring rigidity in some configuration space, (ii) characterizing the (infinitesimal) motions of a formation that preserve desired shapes, (iii) stabilizing a rigid formation towards desired shapes, (iv) reconstruct the formation shape/pose from local pair-wise measurements, or (v) maintaining for- mation rigidity at runtime despite sensing/communication constraints. Parallel robotics is instead concerned about (i) finding the solutions of complex algebraic equations associated with the estimation of the configuration of the end-effector for a given set of active joint positions, and (ii) finding the singular configurations leading to a loss of controllability for the end-effector (loss of mechanical rigidity). These problems in both fields have some similarities that we propose to explore. The next two sections give a more detailed overview of both communities.

Call for Abstract Submission

We invite students and researchers to submit 1-page pdf abstracts to be  presented at an interactive session during the workshop. We encourage  submissions related to the fields of multi-robot formation control and  parallel robotics. Information can be found at the workshop website.

Submission Instructions

Log in in into the scienceconf system using the login button on the top right (you can create an account for free if needed).

Use the submission button on the left column (https://parrigidwrkshp.sciencesconf.org/submission/submit)


This workshop hopes to bring together, at the highest level, audiences from the robotics community and the controls community. We hope the workshop will be of particular interest to researchers and students focusing on formation control theory and parallel robotics. The expected learning outcome of this workshop is to provide every attendant with a clear picture of both communities (open problems, tools, methods, ideas) and of how the two worlds could benefit from each other.


Session 1 (9:00–11:45, w/ coffe break at 10:30) - Rigidity Theory

3 invited talks of 35 minutes each focusing on rigidity theory.
Talks will be a blend of both tutorial style and presentation of recent results in the field.

Speaker 1: Daniel Zelazo

Rigidity theory and formation control: A Tutorial: dowload-pdf

Speaker 2:  Hyo-Sung Ahn

A physical interpretation of the rigidity matrix: download-pdf

Speaker 3:  Shiyu Zhao

Construction of bearing rigid networks in arbitrary dimensions: download-pdf

Interactive Session (11:45–12:30)

The interactive session will be comprised of short 5 minute "teaser" talks followed by "media posters" and informal discussions.


  • MH Trinh, B-H Lee, PH Hoang, Y-B Bae and H-S Ahn 
    Distributed bearing-based formation control via orientation estimation
  • D Six, A Chriette, S Briot and P Martinet
    Design and control of a flying parallel robot
  • A Fomin, V Glazunov, J Paik and E Didenko 
    The design of a new rotary hexapod with a single active degree of freedom
  • B-H Lee and H-S Ahn
    Distributed control for synchronization on cirlce

Session 3 (14:00–16:45 , w/ coffe break at 15:30) - Parallel Robotics

3 invited talks of 35 minutes each focusing on parallel robotics.
Talks will be a blend of both tutorial style and presentation of recent results in the field

Speaker 1:  Jean-Pierre Merlet

Structural topology, singularity, and kinematic analysis: download-pdf

Speaker 2:  Marco Carricato

Screw theory and its application to robotics: dowload-pdf

Speaker 3:  Sébastien Briot

How theory on parallel robot singularities was used in order to solve sensor-based control problems: dowload-pdf

Panel Discussion (16:45–17:30)

A focused panel discussion aimed to wrap up the various contributions and discuss possible concrete ways of cross-exploiting tools/ideas from the two communities.

Organized by

Antonio Franchi

Daniel Zelazo

Sébastien Briot

Paolo Robuffo Giordano


Workshop Registration

Registration for the workshop is handled through the IFAC World Congress registration page.  Information can be found on the IFAC World Congress Registration page.

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