The era of terrifying, headless animal robots has only just begun, it would seem. BigDog has made headlines (over and over) for being strong and versatile, but like the animal it’s named for, Boston Dynamics’ faithful companion has some limitations. Researchers have found that there are some very real advantages to other gaits, and other styles of movement. Published this week in the International Journal of Robotics Research is an article describing a cheetah-cub robot, one that lives up to its name by immediately setting speed records in its weight class.
Cheetah-cub can travel seven times its own body length in a second, which gives it a distinct advantage over other small quadruped robots. In concrete terms, that’s 1.42 meters per second. Using springs to simulate tendons and actuators to replace muscles, the evolutionarily-shaped design of a cat leg is a wonder of versatility. Where most legged robots struggle to deal with uneven terrain, the cheetah cub robot can already move over immediate changes of up to 20% of its own leg length.
The feline leg structure allows incredible speed, but not necessarily long-term efficiency. There’s a reason that wolves run at a moderate velocities but can sustain that speed for truly incredible durations, sometimes whole days. They specialize in running their prey into the ground, while cats prioritize short bursts of speed. They are the sprinters of the animal world, the pouncers, and the hip structure that allows them to explode forward from a standstill is also well suited to their other famous ability: jumping. This robot far too early in development for such applications, but with the feline leg and hip structure already in place, the vertical leap seems like a logical next step for its development.
As the researchers point out in the video above, cats are famously all-terrain. By keeping the body light and attempting to simulate the feline leg as accurately as possible, the researchers could make a robot with unheard-of abilities in balance. The gait is already self-stabilizing without specialized input, which is a believable claim when you think that even a cat with half a brain can run quite effectively. That’s what we call a well-designed skeleton.