BIOROBOTICS LABORATORY
SEOUL NATIONAL UNIVERSITY
CaseCrawler
The CaseCrawler is a lightweight and low-profile movable platform with a high payload capacity; it is capable of crawling around carrying a smartphone. The body of the robot resembles a phone case but it has crawling legs stored in its back. It is designed with a deployable, in-plane transmission that is capable of crawling locomotion. TheCaseCrawler’s leg structure has a knee joint that can passively bend only in one direction; this allows it to sustain a load in the other direction. This anisotropic leg allows a crank slider to be used as the main transmission for generating the crawling motion; the crank slider generates a motion only within a 2D plane. The crank slider deploys the leg when the slider is pushed and retracts it when pulled; this enables a low-profile case that can fully retract the legs flat. Furthermore, by being restricted to swinging within a plane, the hip joint is highly resistant to off-axis deformation, this results in a high payload capacity. As a result, the CaseCrawler has a body thickness of 16 mm (the transmission without the gearbox is only 1.5 mm) and a total weight of 22.7 g;
however, it can carry a load of over 300 g, which is 13 times its own weight. To show the feasibility of the robot for use in real-world
applications, in this study, the CaseCrawler was employed as a movable platform that carries a 190 gmass, including a smartphone
and its cover. This robot can crawl around with the smartphone to enable the phone to charge itself on a wireless charging station.
In the future, if appropriate sensing and control functions are implemented, the robot will be able to collect data or return to the owner when needed.
Keywords : #Crawling
![Figure1.png](https://static.wixstatic.com/media/f10924_53ca59c6fb914a7a8d8992cd4956c929~mv2.png/v1/fill/w_419,h_440,al_c,q_85,usm_0.66_1.00_0.01,enc_auto/Figure1.png)
Related papers and patents
J. Lee, G. P. Jung, S. M. Baek, S. H. Chae, S. Yim, W. Kim, and K. J. Cho, “CaseCrawler: A Lightweight and Low-Profile Crawling Phone Case Robot," IEEE Robot. Autom. Lett., vol. 5, no. 4, pp. 5858-5865, October 2020. [PDF]
Jong-Eun Lee, Gwang-Pil Jung, Kyu-Jin Cho, "Bio-inspired design of a double-sided crawling robot," Living Machines 2017, LNAI 10384, pp. 562–566, 2017. [PDF]
Jong-Eun Lee, Gwang-Pil Jung, Sang-Min Baek and Kyu-Jin Cho, "An adaptive leg structure for a meso-scale crawler," 14th International Conference on Intelligent Unmanned Systems (ICIUS 2018), 2018