Discrete Cosserat Approach for Multi-Section Soft Robots Dynamics (1702.03660v1)

Abstract: In spite of recent progress, soft robotics still suffers from a lack of unified modeling framework. Nowadays, the most adopted model for the design and control of soft robots is the piece-wise constant curvature model, with its consolidated benefits and drawbacks. In this work, an alternative model for multisection soft robots dynamics is presented based on a discrete Cosserat approach, which, not only takes into account shear and torsional deformations, essentials to cope with out-of-plane external loads, but also inherits the geometrical and mechanical properties of the continuous Cosserat model, making it the natural soft robotics counterpart of the traditional rigid robotics dynamics model. The soundness of the model is demonstrated through extensive simulation and experimental results for both plane and out-of-plane motions.

• The paper introduces a novel discrete Cosserat model that accurately captures multi-section soft robot dynamics under variable loads.
• The approach incorporates shear and torsional deformations to simplify kinematics and dynamics analysis, validated by extensive simulations and experiments.
• Experimental insights demonstrate the model’s potential to improve design and control of soft robots in complex, non-planar real-world applications.

Discrete Cosserat Approach for Multi-Section Soft Robots Dynamics

The paper "Discrete Cosserat Approach for Multi-Section Soft Robots Dynamics" introduces a novel modeling framework for soft robotics, specifically addressing multi-section soft robots. This framework offers an alternative to the widely used Piece-Wise Constant Curvature (PCC) models by employing a discrete Cosserat approach. The discrete Cosserat model incorporates shear and torsional deformations, which are essential for handling out-of-plane external loads.

Overview of the Discrete Cosserat Model

1. Unified Framework: The discrete Cosserat model proposed in this paper serves as the soft robotics counterpart to traditional rigid robotics dynamics models. It builds upon the continuous Cosserat approach, allowing for a unified modeling framework that combines geometrical and mechanical properties.
2. Kinematics and Dynamics: The model provides a detailed description of soft robot kinematics and dynamics. It uses strain vectors analogous to joint vectors in rigid robotics, enabling direct calculation of position, velocity, and acceleration. This approach simplifies the complexity typically associated with infinite DoF models.
3. Numerical and Experimental Validation: Extensive simulations of both plane and out-of-plane motions validate the effectiveness of the model. Experimental results further demonstrate its applicability, showing comparable or improved accuracy over continuous Cosserat models.

Numerical Results and Implications

The numerical analysis reveals the model's ability to handle non-constant external loads, proved by comparison with a continuous model applied to a cantilever beam scenario. The discrete model's prediction of oscillation frequency and steady-state errors emphasizes the trade-off between computational simplicity and realism. As more sections are added, the model approaches the continuous representation, minimizing discrepancy.

The paper makes bold assertions by proving the model's performance across different dynamic scenarios, supported by simulation and experimental evidence. Results indicate potential improvements in modeling accuracy, especially concerning concentrated loads within multi-section soft robots.

Theoretical and Practical Implications

The discrete Cosserat approach bridges traditional rigid robotics and soft robotics, offering theoretical insights into the geometric and dynamic modeling of soft manipulators. Practically, it paves the way for better design and control of soft robots, allowing for more complex interactions with environments and tasks requiring precision in non-planar motion scenarios. This framework enables future developments in automation and manipulation in everyday applications, including underwater and medical robotics.

Future Developments in AI and Robotics

The insights gleaned from this work can inform future advances in AI-driven robotics. The discrete Cosserat model's adaptability to different actuation and external load scenarios without structural changes suggests a potential pathway for autonomous systems in complex environments. Specifically, interactively adjusting to dynamic and non-rigid scenarios, this model enhances the applicability of AI in robotics, challenging traditional limitations and embracing a broader range of real-world conditions.

In summary, this paper offers a significant contribution to the soft robotics domain through its discrete Cosserat approach, combining theoretical robustness with practical applicability. The model enhances the precision and computational efficiency in the dynamic simulation of soft robots, paving the way for advancements in complex, real-world robotic applications.