Modeling and Identification for the Design of a Rotary Soft Actuator based on Wren Mechanism In this paper, we describe the use of calibration techniques to help improving prediction accuracy of models for soft actuators. A finitedifference model considering anisotropy of soft actuator flexible chamber is combined with experimental identification to assess actuator motion. Identifiability conditions are exploited to determine suitable experimental conditions, taking into account the manufacturing process capabilities, multimaterial additive manufacturing in this context. As a second contribution, a soft actuator with Wren mechanism for reinforcement is being developed. It is considered for rotary actuation, with the description of a proof of concept. The interest of the calibration technique and the actuator design are finally discussed.

Kinematic Modeling of a Soft Pneumatic Actuator Using Cubic Hermite Splines Soft material robotic systems provide increased adaptability and flexibility compared to conventional rigid metal robots. The soft systems benefit from their inherent compliance, which enables them to be used in applications that require safe interaction between humans and robots or manipulation in cluttered environment. Despite advancements in recent years research on soft material robots still needs to make progress in terms of modeling for model based control or path planning. The high nonlinearity of soft material robots makes efficient and accurate modeling difficult. In this work we introduce a kinematic modeling approach based on cubic hermite splines. The method is applied to a soft pneumatic actuator and evaluated against the widely used constant curvature approach. The hermite spline offers the possibility of accurate shape reconstruction from simulated or measured deformation data. Both the shape of a robotxe2x80x99s segment and its orientation can be approximated this way. In this paper a machine learning approach is used to train the kinematic relation between actuating pressure and configuration parameters.