Design of a spherical tensegrity robot for dynamic locomotion

Kim, Kyunam; Moon, Deaho; Bin, Jae Young; Agogino, Alice M.

doi:10.1109/iros.2017.8202192

Cited by 15 publications

(14 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To the best of authors' knowledge, the twelve-rod tensegrity robot was the first one of its kind introduced in the literature by the authors. 48,49 In addition to the actuation policies for the six-rod tensegrity robots presented in our earlier work, the actuation policies for the twelve-rod tensegrity robot are newly presented in this work, which shows that our methods can work on different tensegrity systems. Furthermore, we newly provide a detailed comparison study of the greedy search and MGMC policies based on three criteria, namely, computation cost, robustness of steps, and required actuation energy.…”

Section: Rolling Locomotion Of Spherical Tensegrity Robotsmentioning

confidence: 82%

“…The first two robots (a, b) are based on a six-rod tensegrity structure, and the last one (c) is based on a twelve-rod tensegrity structure. 48…”

Section: Figmentioning

confidence: 99%

“…46 (c, d) Each edge of the twelve-rod robot consists of an extension spring and a nonstretching string that is spooled in and out by a motor to control the edge length and tension. 48…”

Section: Fig 2 (A B)mentioning

confidence: 99%

“…By means of this work, we aim to consolidate and add to our research to date. [46][47][48][49] We first revisit some of the concepts and techniques presented in our previous work. We start by breaking down the rolling motion of spherical tensegrity robots into a series of piecewise continuous motions, or steps, and classify them based on the geometry of the robots.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Rolling Locomotion of Cable-Driven Soft Spherical Tensegrity Robots

Kim

Agogino

2020

Soft Robotics

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: Rolling Locomotion Of Spherical Tensegrity Robotsmentioning

confidence: 82%

“…The first two robots (a, b) are based on a six-rod tensegrity structure, and the last one (c) is based on a twelve-rod tensegrity structure. 48…”

Section: Figmentioning

confidence: 99%

“…46 (c, d) Each edge of the twelve-rod robot consists of an extension spring and a nonstretching string that is spooled in and out by a motor to control the edge length and tension. 48…”

Section: Fig 2 (A B)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Rolling Locomotion of Cable-Driven Soft Spherical Tensegrity Robots

Kim

Agogino

2020

Soft Robotics

Self Cite

View full text Add to dashboard Cite

show abstract

“…This is due to the complexity of geometric morphologies that are challenging to visualize and requirement of prestress in the cables. Currently, the design methodologies utilize jigs, multiple sets of hands and precise fabrication to achieve symmetric cable tension and link compression (Böhm et al, 2016 ; Chen et al, 2017a ; Kim et al, 2017 ; Cera and Agogino, 2018 ). Recently, planar-to-three-dimensional solutions have been explored using flexible lattice networks which are excellent for fabricating known morphologies which may not be altered post-assembly (Chen et al, 2017a ; Zappetti et al, 2017 ).…”

Section: Introductionmentioning

confidence: 99%

Compact Shape Morphing Tensegrity Robots Capable of Locomotion

2019

View full text Add to dashboard Cite

Robustness, compactness, and portability of tensegrity robots make them suitable candidates for locomotion on unknown terrains. Despite these advantages, challenges remain relating to ease of fabrication, shape morphing (packing-unpacking), and locomotion capabilities. The paper introduces a design methodology for fabricating tensegrity robots of varying morphologies with modular components. The design methodology utilizes perforated links, coplanar (2D) alignment of components and individual cable tensioning to achieve a 3D tensegrity structure. These techniques are utilized to fabricate prism (three-link) tensegrity structures, followed by tensegrity robots in icosahedron (six-link), and shpericon (curved two-link) formation. The methodology is used to explore different robot morphologies that attempt to minimize structural complexity (number of elements) while facilitating smooth locomotion (impact between robot and surface). Locomotion strategies for such robots involve altering the position of center-of-mass (referred to as internal mass shifting) to induce “tip-over.” As an example, a sphericon formation comprising of two orthogonally placed circular arcs with conincident center illustrates smooth locomotion along a line (one degree of freedom). The design of curved links of tensegrity mechanisms facilitates continuous change of the point of contact (along the curve) that results from the tip-over. This contrasts to the sudden and piece-wise continuous change for the case of robots with traditional straight links which generate impulse reaction forces during locomotion. The two resulting robots—the Icosahedron and the Sphericon Tensegrity Robots—display shape morphing (packing-unpacking) capabilities and achieve locomotion through internal mass-shifting. The presented static equilibrium analysis of sphericon with mass is the first step in the direction of dynamic locomotion control of these curved link robots.

show abstract