Dynamically Closed-Loop Controlled Soft Robotic Arm using a Reduced Order Finite Element Model with State Observer

Robert K Katzschmann (1) , Maxime Thieffry (2, 3, 4) , Olivier Goury (2, 4) , Alexandre Kruszewski (2, 5, 4) , Thierry-Marie Guerra (3) , Christian Duriez (2, 4) , Daniela Rus (1)

1 CSAIL - Computer Science and Artificial Intelligence Laboratory [Cambridge]
2 DEFROST - Deformable Robots Simulation Team
3 LAMIH - Laboratoire d'Automatique, de Mécanique et d'Informatique industrielles et Humaines - UMR 8201
4 CRIStAL - Centre de Recherche en Informatique, Signal et Automatique de Lille - UMR 9189
5 Centrale Lille

This paper presents a computationally efficient method to model and simulate soft robots. Finite element methods enable us to simulate and control soft robots, but require us to work with a large dimensional system. This limits their use in real-time simulation and makes those methods less suitable for control design tools. Using model order reduction, it is possible to create a reduced order system for building controllers and observers. Model reduction errors are taken into account in the design of the low-order feedback, and it is then applied to the large dimensional, unreduced model. The control architecture is based on a linearized model of the robot and enables the control of the robot around this equilibrium point. To show the performance of this control method, pose-to-pose and trajectory tracking experiments are conducted on a pneumatically actuated soft arm. The soft arm has 12 independent interior cavities that can be pressurized and cause the arm to move in three dimensions. The arm is made of a rubber material and is casted through a lost-wax fabrication technique.

Domaines: Automatique / Robotique

Robert K Katzschmann, Maxime Thieffry, Olivier Goury, Alexandre Kruszewski, Thierry-Marie Guerra, et al.. Dynamically Closed-Loop Controlled Soft Robotic Arm using a Reduced Order Finite Element Model with State Observer. IEEE 2019 International Conference on Soft Robotics, Apr 2019, Séoul, South Korea. pp.717-724. ⟨hal-02078809⟩