Rolling Locomotion of Cable-Driven Soft Spherical Tensegrity Robots

Soft spherical tensegrity robots are novel steerable mobile robotic platforms that are compliant, lightweight, and robust. The geometry of these robots is suitable for rolling locomotion, and they achieve this motion by properly deforming their structures using carefully chosen actuation strategies. The objective of this work is to consolidate and add to our research to date on methods for realizing rolling locomotion of spherical tensegrity robots. To predict the deformation of tensegrity structures when their member forces are varied, we introduce a modified version of the dynamic relaxation technique and apply it to our tensegrity robots. In addition, we present two techniques to find desirable deformations and actuation strategies that would result in robust rolling locomotion of the robots. The first one relies on the greedy search that can quickly find solutions, and the second one uses a multigeneration Monte Carlo method that can find suboptimal solutions with a higher quality. The methods are illustrated and validated both in simulation and with our hardware robots, which show that our methods are viable means of realizing robust and steerable rolling locomotion of spherical tensegrity robots

What Design Practices Do Professionals Use for Sustainability and Innovation?

Interviews with 27 professionals were performed to investigate what designers, engineers, and their managers value in sustainable design practices, and see how sustainable design practices might also provide innovation. Quantitative and qualitative analysis found that only 1/6th of design practices were valued for both sustainability and innovation; two often-mentioned practices were systems thinking and The Natural Step. Providing a new lens, broadening scope, and problem redefinition were some of the reasons these and other design practices were valued for both sustainability and innovation

What Green Design Activities and Mindsets Drive Innovation and Sustainability in Student Teams?

What sustainable design practices can also drive innovation, and what practices do people value? Previous analysis of sustainable design methods, and the opportunism of designers generally, has suggested that design methods should actually be examined at the level of their component activities and mindsets, as each of these provides different advantages that designers could mix and match. This study performed workshops of three sustainable design methods for a total of 327 students, then surveyed students about which activities or mindsets within each design method drove innovation value, sustainability value, and any other value. The design methods tested were The Natural Step, Whole System Mapping, and Biomimicry. Qualitative and quantitative analyses of surveys found that some activities and mindsets were valued more than others for sustainability, innovation, or both, and to some extent revealed why. Some results were surprising and suggest new research directions

Inclined Surface Locomotion Strategies for Spherical Tensegrity Robots

This paper presents a new teleoperated spherical tensegrity robot capable of performing locomotion on steep inclined surfaces. With a novel control scheme centered around the simultaneous actuation of multiple cables, the robot demonstrates robust climbing on inclined surfaces in hardware experiments and speeds significantly faster than previous spherical tensegrity models. This robot is an improvement over other iterations in the TT-series and the first tensegrity to achieve reliable locomotion on inclined surfaces of up to 24\degree. We analyze locomotion in simulation and hardware under single and multi-cable actuation, and introduce two novel multi-cable actuation policies, suited for steep incline climbing and speed, respectively. We propose compelling justifications for the increased dynamic ability of the robot and motivate development of optimization algorithms able to take advantage of the robot's increased control authority.Comment: 6 pages, 11 figures, IROS 201