Terradynamic streamlining inspired from cockroaches enables legged robots to traverse densely cluttered obstacles. (Top) A discoid cockroach rolls its body to the side and quickly maneuvers through narrow gaps between densely cluttered, grass-like beam obstacles. (Bottom) Adding a rounded, ellipsoidal, exoskeletal shell enables the VelociRoACH legged robot to traverse beam obstacles using roll maneuvers, without adding sensors or changing the open-loop control. Photo Credit: Chen Li. Courtesy of PolyPEDAL Lab, Biomimetic Millisystems Lab, and CiBER, UC Berkeley
Imagine these scenarios: disaster strikes and people unreachably trapped beneath remnants of what used to be a building, your grandmother living across the globe breaks her hip and requires home care but refuses to move closer for you to supervise her care, or you’re on vacation and want to clean your factory’s ventilation system or fix your farmland irrigators.
Professor Chen Li has also envisioned all these situations (and more), as he performs research in the new area of terradynamics, which is analogous to aerodynamics and hydrodynamics, to understand how animals move through challenging terrains by effective mechanical interaction with the environment. With his research, he hopes to bridge the gap between the excellent mobility of vehicles on paved roads and the much more limited mobility of robots in complex terrains, as well as use robots as tools to understand how creatures move across complex terrains.
Li explains, “Right now, we begin to have robotic vehicles like the Google self-driving car that effectively overcome obstacles by moving around them. One of the things I’m trying to do is gain more insight on how creatures like insects and reptiles, rather than always avoiding obstacles, take advantage of mechanical contact with the environment to better traverse more difficult terrain like forest floor, mountain boulders, and desert sand. In learning more about their locomotion, we can translate that knowledge in the development of mobile robots that can better go through cluttered building rubble, rooms, factories, and farmlands to help humans.” (See Movie for an example.)
His interest in animals began at a young age with a fascination by his pet animals and nature documentaries. Yet when he began his undergraduate career at Georgia Tech, he chose a path in materials physics, thinking that it would lead to a career in industry. His plan was disrupted when his rotation took him to Prof. Dan Goldman’s Complex Rheology And Biomechanics (CRAB) Lab.
Prof. Goldman was in the beginning stages of research on the physics of locomotion on challenging ground like sand, and Li’s childhood interest resurfaced as he took a leap of faith and joined Goldman full-time. The story writes itself from there – Li went on to perform postdoctoral research at UC Berkeley with guidance from Professors Robert Full (Biologist) and Ron Fearing (Roboticist). Li will join the Mechanical Engineering Department here at JHU in January 2016.
Professor Li is establishing the Terradynamics Lab here and will continue to systematically research the movement science at the interface of biology, robotics, and physics. He eventually sees a world where, similar to animals, robots can effectively move through all kinds of complex terrains to perform challenging tasks. Databases of terradynamics that describe contact mechanics and predict effective terrestrial movement will be shared among robots via the cloud, to allow them to go beyond where a single robot ever could.
Who knows? The time when robots can serve as human companions – performing search and rescue missions, providing home services, and monitoring and manipulating complex environments in both urban and rural settings might be closer than we think.
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