Ballu is a cool robot presented by Dennis Hong from UCLA’s RoMeLa (Robotics & Mechanisms Laboratory) at the 2016 IEEE International Conference on Humanoid Robots.
BALLU is the acrorym for Buoyancy Assisted Lightweight Legged Unit.
Ballu is a humanoid robot with a body made of helium balloons and a pair of thin articulated legs. Since it weighs next to nothing, it never falls over, and can walk, hop, and perform a variety of other useful bipedal motions
Strictly speaking, BALLU is more like a hybrid airship than a blimp: It’s not lighter than air, so it doesn’t float by itself, and requires some assistance (legs, in this case) for support and to control its motion. Since the robot’s legs don’t have to handle a bunch of weight, they can be skinny little twiggy things, and in fact there’s just one single degree of freedom per leg, in the knee. The knees are cable driven, with the actuators in BALLU’s feet, along with communications and power components. This results in a robot that has the majority of its mass at ground level, making it intrinsically stable, even as it walks forward, walks backward, steps sideways, turns, hops, and more. And BALLU can walk on water
Of course, BALLU is not the kind of robot that’s ever going to carry anything heavy, or do any kind of substantial manipulation tasks: Hong describes it as more of a “walking information device,” whose main asset is the fact that it is lightweight, low cost, and inherently safe.