Stefan Schrade Doctoral Student Other, ETH Zurich Funding: - stefan.schrade@hest.ethz.ch +41 44 510 72 31

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Adaptive Morphology: A Design Principle for Multimodal and Multifunctional Robots

  • Authors: Mintchev, Stefano; Floreano, Dario

Morphology plays an important role in behavioral and locomotion strategies of living and artificial systems. There is biological evidence that adaptive morphological changes can not only extend dynamic performances by reducing tradeoffs during locomotion but also provide new functionalities. In this article, we show that adaptive morphology is an emerging design principle in robotics that benefits from a new generation of soft, variable-stiffness, and functional materials and structures. When moving within a given environment or when transitioning between different substrates, adaptive morphology allows accommodation of opposing dynamic requirements (e.g., maneuverability, stability, efficiency, and speed). Adaptive morphology is also a viable solution to endow robots with additional functionalities, such as transportability, protection, and variable gearing. We identify important research and technological questions, such as variable-stiffness structures, in silico design tools, and adaptive control systems to fully leverage adaptive morphology in robotic systems.

Posted on: September 27, 2016

Minimalist Design of a 3-Axis Passive Compliant Foot for Sprawling Posture Robots

Authors: Melo, K. ; Horvat, T. ; Ijspeert, A. J.

Abstract

A sprawled posture amphibious biorobot resembling a salamander had helped us in conquering scientific questions of the locomotion of these animals and offer us with technological possibilities for applications in disaster response. However, so far the foot structure of these robots is simplified in a ball foot that occludes many interesting aspects of the rich dynamics of interaction with the ground that these animals/robots have. In this paper, we present a minimalist design of a three degree of freedom foot that uses passive mechanics, soft materials and simple fabrication techniques to achieve features observed in sprawling posture animals walking gaits. The parameters of our design can be adjusted for specific visco-elastic properties (stiffness, damping) and easily adapted to different sizes and forms. We presented the fabrication technique used to achieve several configurations of the foot structure. Stress analysis of the design helped us to verify the right selection of materials and configurations to achieve desired behaviors. We expect to use these feet for better understanding the limb-ground interaction in sprawled animals as well as improving the locomotion capabilities of biorobots in general.

Reference

  • Published in: 2019 2nd IEEE International Conference on Soft Robotics (Robosoft 2019), 788-794
  • DOI: 10.1109/ROBOSOFT.2019.8722792
  • Read paper
  • Date: 2019
Posted on: May 10, 2020

Minimalistic Models of an Energy Efficient Vertical Hopping Robot

  • Authors: Yu, Xiaoxiang; Iida, Fumiya

The use of free vibration in elastic structure can lead to energy efficient robot locomotion, since it significantly reduces the energy expenditure if properly designed and controlled. However, it is not well understood how to harness the dynamics of free vibration for the robot locomotion, because of the complex dynamics originated in discrete events and energy dissipation during locomotion. From this perspective, the goal of this paper is to propose a design strategy of hopping robot based on elastic curved beams and actuated rotating masses, and identify the minimalistic model that can characterize the basic principle of robot locomotion. Since the robot mainly exhibits vertical hopping, three one-dimensional models are examined that contain different configurations of simple spring-damper-mass components. The real-world and simulation experiments show that one of the models best characterizes the robot hopping, through analyzing the basic kinematics and negative works in actuation. Based on this model, the self-stability of hopping motion under disturbances is investigated and design and control parameters are analyzed for the energy efficient hopping. Additionally, further analyses show that this robot can achieve the energy efficient hopping with the variation in payload, and the source of energy dissipation of the robot hopping is investigated.

Posted on: September 9, 2013

StarlETH: A compliant quadrupedal robot for fast, efficient, and versatile locomotion

  • Authors: Hutter, M.; Gehring, C.; Bloesch, M.; Hoepflinger, M. A.; Remy, C. D.; Siegwart, R.

This paper introduces StarlETH, a compliant quadrupedal robot that is designed to study fast, efficient, and versatile locomotion. The platform is fully actuated with high compliant series elastic actuation, making the system torque controllable and at the same time well suited for highly dynamic maneuvers. We additionally emphasize key elements of a powerful real time control and simulation environment. The work is concluded with a number of experiments that demonstrate the performance of the presented hardware and controllers.

Posted on: August 27, 2012