Georgia Tech’s Mobile Robot Gets Legs for Off-Roading

Most robots are designed with a locomotion system that best suits the environment they operate in, such as wheels for flat surfaces, or legs for uneven outdoor terrain. Researchers from Georgia Tech’s DART Laboratory have developed a locomotion system that uses both to adapt to any terrain physically, and will even allow their mobile robot to swim in the water. The robot uses what the researchers term as “swappable propulsors,” a platform that enables adaptive ground mobility to optimize performance across various terrain.

The robot is outfitted with a manipulator arm, which it uses to add or remove legs that slide in and out of T-shape slots and remain secure using a geometric shape and permanent magnets. The design allows for a high holding force and a low detachment force, making it easy for the arm to swap-out its legs. That said, the swappable propulsor design means the robot has to carry its legs with it where ever it goes, which means it also needs to be outfitted with the robotic arm as well. That trade-off is also a payoff, as the arm allows it to do more than just swap-out legs.

During tests, the researchers have shown that their swappable propulsors and manipulator arm platform makes a substantial difference in efficiency over using a single mode of locomotion. In its wheeled mode while on flat concrete, the robot had a COT (Cost of Transport) of 0.97 for the amount of energy consumed during movement, which the researchers state “represents a roughly three-fold decrease when compared to using legs on flat surfaces.” They are also looking to add additional capabilities in the future, including adding a perception and mapping system for efficient navigation to reduce the robot’s energy consumption.