List of all recorded talks

  • Automated Throwing and Capturing of Cylinder-Shaped Objects Authors: Frank, Thorsten; Janoske, Uwe; Mittnacht, Anton; Schroedter, Christian
    A new approach for transportation of objects within production systems by automated throwing and capturing is investigated. This paper presents an implementation, consisting of a throwing robot and a capturing robot. The throwing robot uses a linear and the capturing robot a rotary axis. The throwing robot is capable of throwing cylinder-shaped objects onto a target point with high precision. The capturing robot there smoothly grips the cylinders during flight by means of a rotational movement. In order to synchronize the capturing robot and the cylinder’s pose and velocity, its trajectory has to be modeled as well as the motion sequences of both robots. The throwing and capturing tasks are performed by the robots automatically without the use of any external sensor system.
  • Design and Development of a Soft Robotic Octopus Arm Exploiting Embodied Intelligence Authors: Cianchetti, Matteo; Follador, Maurizio; Mazzolai, Barbara; Dario, Paolo; Laschi, Cecilia
    The octopus is a marine animal whose body has no rigid structures. It has eight arms mainly composed of muscles organized in a peculiar structure, named muscular hydrostat, that can change stiffness and that is used as a sort of a modifiable skeleton. Furthermore, the morphology of the arms and the mechanical characteristics of their tissues are such that the interaction with the environment, namely water, is exploited to simplify the control of movements. From these considerations, the octopus emerges as a paradigmatic example of embodied intelligence and a good model for soft robotics. In this paper the design and the development of an artificial muscular hydrostat are reported, underling the efforts in the design and development of new technologies for soft robotics, like materials, mechanisms, soft actuators. The first prototype of soft robot arm is presented, with experimental results that show its capability to perform the basic movements of the octopus arm (like elongation, shortening, and bending) and demonstrate how embodiment can be effective in the design of robots.
  • The Application of Embodiment Theory to the Design and Control of an Octopus-Like Robotic Arm Authors: Guglielmino, Emanuele; Zullo, Letizia; Cianchetti, Matteo; Follador, Maurizio; Branson, David; Caldwell, Darwin G.
    This paper examines the design and control of a robotic arm inspired by the anatomy and neurophysiology of Octopus vulgaris in light of embodiment theory. Embodiment in an animal is defined as the dynamic coupling between sensory-motor control, anatomy, materials, and the environment that allows for the animal to achieve effective behaviour. Octopuses in particular are highly embodied and dexterous animals: their arms are fully flexible, can bend in any direction, grasp objects and modulate stiffness along their length. In this paper the biomechanics and neurophysiology of octopus have been analysed to extract relevant information for use in the design and control of an embodied soft robotic arm. The embodied design requirements are firstly defined, and how the biology of the octopus meets these requirements presented. Next, a prototype continuum arm and control architecture based on octopus biology, and meeting the design criteria, are presented. Finally, experimental results are presented to show how the developed prototype arm is able to reproduce motions performed by live octopus for contraction, elongation, bending, and grasping.
  • Control Architecture for Robots with Continuum Arms Inspired by Octopus Vulgaris Neurophysiology Authors: Branson, David; Kang, Rongjie; Guglielmino, Emanuele; Caldwell, Darwin G.
    Conventional rigid body robots typically use few degrees of freedom (DOF). This results in a manipulator that lacks flexibility and maneuverability when compared to continuum robots that utilize a much higher number of DOF. However, due to their continuous nature, the difficulty of measuring and controlling a large number of actuated DOF, and their high degree of nonlinearity, the development of control algorithms for continuum robot manipulators is an ongoing challenge. This paper presents an algorithm inspired by biological solutions from live octopus that utilizes division of functionality to achieve simple and robust control of continuum arm based systems. Simulated results for single and multiple dynamic continuum arms show the controller is capable of producing motions similar to that of octopus. The resulting controller is also computationally efficient enough for real-time implementation. In future this work will be implemented on a prototype robot with multiple continuum arms.
  • Dynamic Continuum Arm Model for Use with Underwater Robotic Manipulators Inspired by Octopus Vulgaris Authors: Zheng, Tianjiang; Branson, David; Kang, Rongjie; Cianchetti, Matteo; Guglielmino, Emanuele; Follador, Maurizio; Medrano-Cerda, Gustavo; Godage, Isuru S.; Caldwell, Darwin G.
    Continuum structures with a very high or infinite number of degrees of freedom (DOF) are very interesting structures in nature. Mimicking this kind of structures artificially is challenging due to the high number of required DOF. This paper presents a kinematic and dynamic model for an underwater robotic manipulator inspired by Octopus vulgaris. Then, a prototype arm inspired by live octopus is presented and the model validated experimentally. Initial comparisons of simulated and experimental results show good agreement.
  • Hydrodynamic Analysis of Octopus-Like Robotic Arms Authors: Kazakidi, Asimina; Vavourakis, Vasileios; Pateromichelakis, Nikolaos; Ekaterinaris, John A.; Tsakiris, Dimitris
    We consider robotic analogues of the arms of the octopus, a cephalopod exhibiting a wide variety of dexterous movements and complex shapes, moving in an aquatic environment. Although an invertebrate, the octopus can vary the stiffness of its long arms and generate large forces, while also performing rapid motions within its aquatic environment. Previous studies of elongated robotic systems, moving in fluid environments, have mostly oversimplified the effects of flow and the generated hydrodynamic forces, in their dynamical models. The present paper uses computational fluid dynamic (CFD) analysis to perform high-fidelity numerical simulations of robotic prototypes emulating the morphology of octopus arms. The direction of the flow stream and the arm geometry (e.g., the presence of suckers), were among the parameters that were shown to affect significantly the flow field structure and the resulting hydrodynamic forces, which have a non-uniform distribution along the arm. The CFD results are supported by vortex visualization experiments in a water tank. The results of this investigation are being exploited for the design of soft-bodied robotic systems and the development of related motion control strategies.
  • Design and Performance of Nubbed Fluidizing Jamming Grippers Authors: Kapadia, Jaimeen; Yim, Mark
    Grippers have been shown using jamming of granular media grasp a large range of objects by pushing against them (with an activation force) to conform the gripper to the object’s shape before grasping them with the intent to make universal grippers. This paper presents two effective modifications to jamming gripper designs (adding small nubs and fluidizing the granular media) resulting in significantly larger holding forces (typically 60%) and increasing the range of object geometries. The paper presents the design and fabrication of these devices and explores the range of objects and conditions empirically. Experiments also show that the nubs enable the grasping of smaller objects in which the gripper can engage interlocking forces in the granular media.
  • Opportunistic Localization of Underwater Robots Using Drifters and Boats Authors: Arrichiello, Filippo; Heidarsson, Hordur K; Sukhatme, Gaurav
    The paper characterizes the localization performance of an Autonomous Underwater Vehicle (AUV) when it moves in environments where floating drifters or surface vessels are present and can be used for relative localization. In particular, we study how localization performance is affected by parameters e.g. AUV mobility, surface objects density, the available measurements (ranging and/or bearing) and their visibility range. We refer to known techniques for estimation performance evaluation and probabilistic mobility models, and we bring them together to provide a solid numerical analysis for the considered problem. We perform an extensive simulations in different scenarios, and, as a proof of concept, we show how an AUV, equipped with an upward looking sonar, can improve its localization estimate by detecting a surface vessel.
  • Tracking of a Tagged Leopard Shark with an AUV: Sensor Calibration and State Estimation Authors: Forney, Christina; Manii, Esfandiar; Farris, Michael; Moline, Mark A.; Lowe, Christopher G.; Clark, Christopher M.
    Presented is a method for estimating the 2D planar position, velocity, and orientation states of a tagged shark. The method is designed for implementation on an Autonomous Underwater Vehicle (AUV) equipped with a stereo-hydrophone and receiver system that detects acoustic signals transmitted by a tag. The particular hydrophone system used here provides a measurement of relative bearing angle to the tag, but does not provide the sign (+ or -) of the bearing angle. A Particle Filter was used for fusing these measurements over time to produce a state estimate of the tag location. The Particle Filter combined with an active control system allowed the system to overcome the ambiguity in the sign of the bearing angle. This state estimator was validated by tracking both a stationary tag and moving tag with known positions. These experiments revealed state estimate errors were on par with those obtained by manually driven boat based tracking systems, the current method used for tracking fish and sharks over long distances. Final experiments involved the catching, releasing, and an autonomous AUV tracking of a 1 meter Leopard Shark (<i>Triakis semifasciata<i>) in SeaPlane Lagoon, Los Angeles, California.
  • An Experimental Momentum-Based Front Detection Method for Autonomous Underwater Vehicles Authors: Gottlieb, Jeremy; Graham, Rishi; Maughan, Thom; Py, Frederic; Ryan, John; Elkaim, Gabriel Hugh; Rajan, Kanna
    Fronts have been recognized as hotspots of intense biological activity. They are therefore important targets for observation to understand coastal ecology and transport in a changing ocean. With high spatial and tem- poral variability, detection and event response for frontal zones is challenging. Robotic platforms like autonomous underwater vehicles (AUVs) have shown their versatility in using automated approaches to detect a range of features; directing them using in-situ and on-shore capabilities for front detection then becomes an important tool for observ- ing such rapid and episodic changes. We introduce a novel momentum-based front detection (MBFD) algorithm de- signed to automatically detect frontal zones. MBFD utilizes a Kalman filter and a momentum accumulator function to identify significant temperature gradients associated with upwelling fronts. MBFD is designed to work at a number of levels including onboard an autonomous underwater vehicle (AUV); on-shore with a sparse, real-time data stream and post-experiment on a hi-resolution data set gathered by a robot. Such a multi-layered approach plays an important role in mixed human-computer decision making for oceanographers making coordinating sampling and asset allocation strategies in large multi-robot field experiments in the coastal ocean.