Tactile Perception for Growing Robots via Discrete Curvature Measurements

摘要

Soft, growing robots have the ability to conform to their environment and traverse highly curved paths that would typically prove challenging for other robot designs. As they navigate through these constrained and cluttered environments, there is often significant interaction between the robot and its surroundings. In this work, we propose a method to enable tactile perception for growing robots, which utilizes commercially available, flexible sensors that measure the curvature of the robot shape at multiple locations. Our method consists of both a pouch design to enable seamless integration of the sensors with the material of the growing robot, as well as an algorithm for determining the location of point contacts along the robot body. We validate our proposed approach experimentally using a 3.5 cm robot that can grow to be 53 cm long. We show that we can localize a force applied to various locations along its length with an average error of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3.444\pm1.38$</tex> cm when the robot is unactuated and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$4.62\pm 0.95$</tex> cm when the robot is actuated. Additionally, we characterize the minimum distance required for our tactile sensing approach to discriminate between two separate contact points along the robot body to be 23.5 cm. Finally, we apply our method to a growing robot exploring an unknown environment and show that we are able to effectively determine when and where the growing robot collides with an unknown obstacle.