Dima in action

Dima’s tail acts as a counterbalance to the car’s high center of gravity. (Other tailed robot vehicles, like Robert Full’s example, use tails to control the horizontal motion of yaw rather than its fore-aft counterpart, roll.) Normally, top-heavy cars are poor handlers, and engineers go to great lengths to push as much of a vehicle’s weight as low as possible.

Vehicles with low centers of gravity are remarkably stable. Take the Tesla Model S, for example. The bulk of the car’s weight is tied up in its batteries, which are are located under the floor of the passenger compartment. The Model S is so unflappable that, to test the strength of its roof in a rollover, crash testers had to devise a new way to get the vehicle to turn over—they couldn’t get it to flip at normal test speeds.

dima-robot
Dima's tail gives it uncanny stability.

Some vehicles, though, can’t be that low to the ground. Off-road racing trucks, for example, have to be jacked up to clear obstacles, a necessity which robs them of speed on turns. The same is true of military Humvees. An actuated tail like Dima’s could help keep them stable without sacrificing handling or ride height. Even vehicles that are low to the ground could benefit. Turning transfers a vehicle’s mass to one set of tires, reducing overall grip. A movable tail could help keep the mass more evenly distributed over all four wheels, providing more grip and allowing the vehicle to make turns at even higher speeds.

Read more about bioinspired robots here at NOVA Next.

For more bioinspired engineering, watch "Making Stuff Safer."
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