Characterization of the Growing From the Tip as Robot Locomotion Strategy

Abstract

Growing robots are a new class of robots able to move in the environment exploiting a growing from the tip process (movement by growing). Thanks to this property, these robots are able to navigate 3D environments while negotiating confined spaces and large voids by adapting their body. During the exploration of the environment, the tip of the robot is able to move in any direction and can be kinematically considered as a non-holonomic mobile system. In this paper, we show the kinematics of robot growing at its tip level. We also present the affordable workspace analyzed by an evaluation of feasible trajectories toward target poses. The geometrical key parameters imposing constraints on growing robots' workspace are discussed, in view of facing different possible application scenarios. The proposed kinematics was applied to a plant-inspired growing robot moving in a 3D environment in simulation, obtaining ∼2 cm error after 1 m of displacement. With appropriate parametrization, the proposed kinematic model is able to describe the motion from the tip in robots able to grow.

Mechanical Innovations of a Climbing Cactus: Functional Insights for a New Generation of Growing Robots

“…Ensuring reach across spaces via growth represents a significant challenge for plants as well as robotic artifacts. Recent studies have made great progress in developing growing root-like robots for movement in soil (Sadeghi et al, 2014 , 2016 ) and for movements comparable to climbing plant stems in air and in relation to supports (Del Dottore et al, 2019 ). These approaches require potentially different behaviors and technological innovations.…”

“…Bioinspired studies based on plants are now increasingly turning toward soft robotic applications (Mazzolai et al, 2014 ; Mazzolai, 2017 ). A turning point is that movement via adaptive growth is being integrated into bioinspired designs for artifacts to grow and move by artificial growth and movements like plant stems (Hawkes et al, 2017 ), tendrils (Must et al, 2019 ), tendril and searcher like structures (Mehling et al, 2006 ; Wooten and Walker, 2018 ; Wooten et al, 2018 ) and roots (Sadeghi et al, 2014 , 2016 ; Del Dottore et al, 2019 ). The approach also considers how plants develop and adapt their modes of growth and varying stem stiffness and rigidity to locate supports as well as attaching and climbing on different substrates.…”

“…This is especially crucial for reaching across voids and avoiding buckling. Scaled-up structures must be still capable of adaptively keeping on course toward the desired support e.g., (Del Dottore et al, 2019 ) and minimizing constructional cost and mass in terms of energy and materials. We investigated developmental changes of a cactus species that develops a large diameter stem via primary growth of soft tissues.…”

Robust navigation of a soft growing robot by exploiting contact with the environment

“…These models characterize a continuum robot by specially chosen points along the robot’s backbone. Examples of lumped parameter models of continuum robots include the unicycle model developed by Park et al (2005) and bicycle model developed by Webster and Jones (2010), both for steerable needles, as well as a recent model developed by Del Dottore et al (2019) describing the motion of a growing robot in free space. We also use a lumped parameter kinematic model in this article.…”

Editorial: Advances in Soft Robotics Based on Outputs From IROS 2018

“…Soft robots can adapt to variable environments and they can move adapting themselves to the requirements of the task. They can manipulate unknown objects that vary in size and shape (Hughes et al, 2016 ) and their soft conditions allow them to access and operate in confined spaces, to adapt their shape and even to grow (Del Dottore et al, 2019 ) and self-heal (Bilodeau and Kramer-Bottiglio, 2017 ). Soft robotics poses interesting challenges for research in several aspects from manufacturing (Schmitt et al, 2018 ) and control ( Mena et al ; Muñoz et al, 2020 ).…”