Octopus arm kinematic analysis for use in multi-arm underwater robotic swimmers

The extraction of accurate kinematic information of animal appendages is of great importance for many biologically-inspired robotic applications. Octopus arm trajectories during a two-stroke arm-swimming motion have been initially analyzed through a vision-based 3D process, that reconstructs the arm spatial configurations and captures their 3D motion; this work is presented in [Kazakidi et al, ICRA 2015, Paper WeA2T9.9]. However, these results cannot be directly applied in multi-arm robotic swimmers. To that end, we analyze further the biological arm trajectories and extract related reduced models, exploiting multi-segment arm models with spherical joints between the arms. We, thus, obtain arm joint trajectory data, which could be directly applicable to the control of octopus-inspired multi-arm robotic swimmers. In this poster, we present recent related results and their applicability to our octopus-inspired compliant underwater robotic swimmer [Sfakiotakis et al, IROS 2014, pp. 302-308]. We will also discuss possible biological implications of these results for the octopus arm-swimming behavior and its propulsive capability.