“Energy efficiency meant calculating energy input and energy output. The energy output is kinetic energy and potential energy at the moment of takeoff, and when the robot’s feet stop touching the ground. defined as a moment in time,” explains Shin. Energy input was calculated by measuring the power used during takeoff.
“It turns out that jumping takeoff is actually the most energy-efficient strategy. We didn’t expect that result. We were very surprised,” says Singh.
The energy cost of jump takeoff is slightly higher than the other two strategies, but not by much. It required 7.9 percent more juice than a standing takeoff and 6.9 percent more juice than a fall takeoff. At the same time, higher accelerations were produced, resulting in much better value for money (at least as far as energy is concerned). Overall, jumping on bird-like legs was 9.7 times more efficient than standing and taking off, and 4.9 times more efficient than taking off while falling.
One caveat in the team’s calculations is that fixed-wing drones, which are more conventional designs using wheels and launchers, are much more efficient in traditional takeoff strategies than legged RAVEN robots. That’s what it meant. “But if you think about it, birds would also be able to fly better without legs. They still need animals to move on the ground and hunt prey. They trade off some of their efficiency in flight. , you can get more functionality,” Shin asserts. And the legs had many functions.
There is an obstacle ahead
To demonstrate the versatility of legged flying robots, Singh’s team had them perform a series of tasks that standard drones cannot complete. Their baseline mission scenario included traversing low-ceilinged paths, jumping over gaps, and jumping over obstacles. “If the tail touches the ground and assumes an upright position, the robot can walk and remain stable without sophisticated controllers,” Singh claims. The problem of moving under low ceilings was solved by walking. Jumping over gaps and obstacles was accomplished using a mechanism called torsion springs and actuators, which are used during takeoff. Raven was able to jump through gaps 11 centimeters wide and jump over obstacles 26 centimeters high.
