Liana Tilton - Academia.edu (original) (raw)

Papers by Liana Tilton

ArXiv, 2020

Many organisms, including various species of spiders and caterpillars, change their shape to swit... more Many organisms, including various species of spiders and caterpillars, change their shape to switch gaits and adapt to different environments. Recent technological advances, ranging from stretchable circuits to highly deformable soft robots, have begun to make shape changing robots a possibility. However, it is currently unclear how and when shape change should occur, and what capabilities could be gained, leading to a wide range of unsolved design and control problems. To begin addressing these questions, here we simulate, design, and build a soft robot that utilizes shape change to achieve locomotion over both a flat and inclined surface. Modeling this robot in simulation, we explore its capabilities in two environments and demonstrate the automated discovery of environment-specific shapes and gaits that successfully transfer to the physical hardware. We found that the shape-changing robot traverses these environments better than an equivalent but non-morphing robot, in simulation...

Soft robots provide a unique capability over rigid machines: the ability to continuously change t... more Soft robots provide a unique capability over rigid machines: the ability to continuously change their shape on demand. As demonstrated by organisms capable of shape change, this behavior has several desirable properties, including the ability to enter and operate in a wider range of environments, or manipulate objects with greater delicacy than a fixed-shape organism can. Introducing shape as a control variable leads to a rich yet complicated range of configurations, opening up a wide range of possibilities for multi-functional, shape-changing robots. Here, we present a target pipeline for the automatic design of soft-bodied, shape-changing robots to accomplish an input task, such as locomotion or grasping. We demonstrate working aspects of such a pipeline as we attempt sim2real transfer of morphing robots. In this context, we explore the current role of simulation, shortcomings of current soft robot simulators, and discuss methods for overcoming such shortcomings.

IEEE Robotics and Automation Letters, 2019

Shape versatility is a mechanism that many animals leverage to effectively interact-with and loco... more Shape versatility is a mechanism that many animals leverage to effectively interact-with and locomote-within the natural world. Towards the goal of shape-changing artificial systems, we present morphing robots comprised of robotic skins and sculptable materials. Herein, we describe robotic skinsplanar, skin-like substrates with embedded actuation-that are wrapped around sculptable materials in order to actively shape those materials into different forms. Our approach is inspired by the art of sculpture, where surface strains and pressures applied by hand allow clay to be sculpted into nearly any desired shape. Replacing hands with robotic skins, we achieve morphing capabilities in a robotic system. We focus on an example robot in which two robotic skins are layered on a base sculptable material to induce both locomotion and morphing behaviors, and show that morphing enables the robot to overcome obstacles during locomotion. This paper is the first instantiation of morphing robots based on sculpture-inspired surface manipulation of sculptable materials, where shape-changing capabilities are expected to improve robot adaptability to meet the demands of changing environments, overcome obstacles, or perform variable tasks.

Nature Machine Intelligence, 2020

N ature provides several examples of organisms that utilize shape change as a means of operating ... more N ature provides several examples of organisms that utilize shape change as a means of operating in challenging, dynamic environments. For example, the spider Araneus rechenbergi 1,2 and the caterpillar of the mother-of-pearl moth (Pleurotya ruralis) 3 transition from walking gaits to rolling in an attempt to escape predation. Across larger timescales, caterpillar-to-butterfly metamorphosis enables land-to-air transitions, while mobile to sessile metamorphosis, as observed in sea squirts, is accompanied by radical morphological change. Inspired by such change, engineers have created caterpillar-like rolling 4 , modular 5-7 , tensegrity 8,9 , plant-like growing 10 and origami 11,12 robots that are capable of some degree of shape change. However, progress towards robots that dynamically adapt their resting shape to attain different modes of locomotion is still limited. Further, design of such robots and their controllers is still a manually intensive process. Despite the growing recognition of the importance of morphology and embodiment on enabling intelligent behaviour in robots 13 , most previous studies have approached the challenge of operating in multiple environments primarily through the design of appropriate control strategies. For example, engineers have created robots that can adapt their gaits to locomote over different types of terrain 14-16 , transition from water to land 17,18 and transition from air to ground 19-21. Other research has considered how control policies should change in response to changing loading conditions 22,23 , or where the robot's body was damaged 24-26. Algorithms have also been proposed to exploit gait changes that result from changing the relative location of modules and actuators 27 , or tuning mechanical parameters, such as stiffness 28. In such approaches, the resting dimensions of the robot's components remained constant. These robots could not, for instance, actively switch their body shape between a quadrupedal form and a rolling-optimized shape. The emerging field of soft robotics holds promise for building shape-changing machines 29. For example, one robot switched between spherical and cylindrical shapes using an external magnetic field, which could potentially be useful for navigating internal organs such as the oesophagus and stomach 30. Robotic skins

ArXiv, 2020

Many organisms, including various species of spiders and caterpillars, change their shape to swit... more Many organisms, including various species of spiders and caterpillars, change their shape to switch gaits and adapt to different environments. Recent technological advances, ranging from stretchable circuits to highly deformable soft robots, have begun to make shape changing robots a possibility. However, it is currently unclear how and when shape change should occur, and what capabilities could be gained, leading to a wide range of unsolved design and control problems. To begin addressing these questions, here we simulate, design, and build a soft robot that utilizes shape change to achieve locomotion over both a flat and inclined surface. Modeling this robot in simulation, we explore its capabilities in two environments and demonstrate the automated discovery of environment-specific shapes and gaits that successfully transfer to the physical hardware. We found that the shape-changing robot traverses these environments better than an equivalent but non-morphing robot, in simulation...

Soft robots provide a unique capability over rigid machines: the ability to continuously change t... more Soft robots provide a unique capability over rigid machines: the ability to continuously change their shape on demand. As demonstrated by organisms capable of shape change, this behavior has several desirable properties, including the ability to enter and operate in a wider range of environments, or manipulate objects with greater delicacy than a fixed-shape organism can. Introducing shape as a control variable leads to a rich yet complicated range of configurations, opening up a wide range of possibilities for multi-functional, shape-changing robots. Here, we present a target pipeline for the automatic design of soft-bodied, shape-changing robots to accomplish an input task, such as locomotion or grasping. We demonstrate working aspects of such a pipeline as we attempt sim2real transfer of morphing robots. In this context, we explore the current role of simulation, shortcomings of current soft robot simulators, and discuss methods for overcoming such shortcomings.

IEEE Robotics and Automation Letters, 2019

Shape versatility is a mechanism that many animals leverage to effectively interact-with and loco... more Shape versatility is a mechanism that many animals leverage to effectively interact-with and locomote-within the natural world. Towards the goal of shape-changing artificial systems, we present morphing robots comprised of robotic skins and sculptable materials. Herein, we describe robotic skinsplanar, skin-like substrates with embedded actuation-that are wrapped around sculptable materials in order to actively shape those materials into different forms. Our approach is inspired by the art of sculpture, where surface strains and pressures applied by hand allow clay to be sculpted into nearly any desired shape. Replacing hands with robotic skins, we achieve morphing capabilities in a robotic system. We focus on an example robot in which two robotic skins are layered on a base sculptable material to induce both locomotion and morphing behaviors, and show that morphing enables the robot to overcome obstacles during locomotion. This paper is the first instantiation of morphing robots based on sculpture-inspired surface manipulation of sculptable materials, where shape-changing capabilities are expected to improve robot adaptability to meet the demands of changing environments, overcome obstacles, or perform variable tasks.

Nature Machine Intelligence, 2020

N ature provides several examples of organisms that utilize shape change as a means of operating ... more N ature provides several examples of organisms that utilize shape change as a means of operating in challenging, dynamic environments. For example, the spider Araneus rechenbergi 1,2 and the caterpillar of the mother-of-pearl moth (Pleurotya ruralis) 3 transition from walking gaits to rolling in an attempt to escape predation. Across larger timescales, caterpillar-to-butterfly metamorphosis enables land-to-air transitions, while mobile to sessile metamorphosis, as observed in sea squirts, is accompanied by radical morphological change. Inspired by such change, engineers have created caterpillar-like rolling 4 , modular 5-7 , tensegrity 8,9 , plant-like growing 10 and origami 11,12 robots that are capable of some degree of shape change. However, progress towards robots that dynamically adapt their resting shape to attain different modes of locomotion is still limited. Further, design of such robots and their controllers is still a manually intensive process. Despite the growing recognition of the importance of morphology and embodiment on enabling intelligent behaviour in robots 13 , most previous studies have approached the challenge of operating in multiple environments primarily through the design of appropriate control strategies. For example, engineers have created robots that can adapt their gaits to locomote over different types of terrain 14-16 , transition from water to land 17,18 and transition from air to ground 19-21. Other research has considered how control policies should change in response to changing loading conditions 22,23 , or where the robot's body was damaged 24-26. Algorithms have also been proposed to exploit gait changes that result from changing the relative location of modules and actuators 27 , or tuning mechanical parameters, such as stiffness 28. In such approaches, the resting dimensions of the robot's components remained constant. These robots could not, for instance, actively switch their body shape between a quadrupedal form and a rolling-optimized shape. The emerging field of soft robotics holds promise for building shape-changing machines 29. For example, one robot switched between spherical and cylindrical shapes using an external magnetic field, which could potentially be useful for navigating internal organs such as the oesophagus and stomach 30. Robotic skins