Institute of Fundamental Technological Research
Polish Academy of Sciences


Stephane Bordas

University of Luxembourg (LU)

Recent publications
1.  Piranda B., Chodkiewicz P., Hołobut P., Bordas S.P.A., Bourgeois J., Lengiewicz J., Distributed prediction of unsafe reconfiguration scenarios of modular robotic programmable matter, IEEE TRANSACTIONS ON ROBOTICS, ISSN: 1552-3098, DOI: 10.1109/TRO.2021.3074085, pp.1-8, 2021

We present a distributed framework for predicting whether a planned reconfiguration step of a modular robot will mechanically overload the structure, causing it to break or lose stability under its own weight. The algorithm is executed by the modular robot itself and based on a distributed iterative solution of mechanical equilibrium equations derived from a simplified model of the robot. The model treats intermodular connections as beams and assumes no-sliding contact between the modules and the ground. We also provide a procedure for simplified instability detection. The algorithm is verified in the Programmable Matter simulator VisibleSim, and in real-life experiments on the modular robotic system Blinky Blocks.

distributed algorithms, modular robots, mechanical constraints, programmable matter, self-reconfiguration

Piranda B. - other affiliation
Chodkiewicz P. - Warsaw University of Technology (PL)
Hołobut P. - IPPT PAN
Bordas S.P.A. - University of Luxembourg (LU)
Bourgeois J. - other affiliation
Lengiewicz J. - IPPT PAN

Conference papers
1.  Hołobut P., Bordas S.P.A., Lengiewicz J., Autonomous model-based assessment of mechanical failures of reconfigurable modular robots with a conjugate gradient solver, IROS, International Conference on Intelligent Robots and Systems, 2020-10-25/10-29, Las Vegas (US), pp.11696-11702, 2020

Large-scale 3D autonomous self-reconfigurable modular robots are made of numerous interconnected robotic modules that operate in a close packing. The modules are assumed to have their own CPU and memory, and are only able to communicate with their direct neighbors. As such, the robots embody a special computing architecture: a distributed memory and distributed CPU system with a local messagepassing interface. The modules can move and rearrange themselves changing the robot's connection topology. This may potentially cause mechanical failures (e.g., overloading of some inter-modular connections), which are irreversible and need to be detected in advance. In the present contribution, we further develop the idea of performing model-based detection of mechanical failures, posed in the form of balance equations solved by the modular robot itself in a distributed manner. A special implementation of the Conjugate Gradient iterative solution method is proposed and shown to greatly reduce the required number of iterations compared with the weighted Jacobi method used previously. The algorithm is verified in a virtual test bed—the VisibleSim emulator of the modular robot. The assessments of time-, CPU-, communication- and memory complexities of the proposed scheme are provided.

Hołobut P. - IPPT PAN
Bordas S.P.A. - University of Luxembourg (LU)
Lengiewicz J. - IPPT PAN

Category A Plus


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