There are things that humans take for granted, but for a robot they are a huge challenge. For example, when they have to go down stairs, jump over something or balance. Engineers at California Polytechnic University, or Caltech, have solved this by replacing the arms of Leonardo with two propellers, so the 70-centimetre robot can easily negotiate any obstacle – it can even balance on a stretched rope, just like birds balance on the wires of a light pole.
The leg-articulated robot walks like a human, but it also makes use of propellers, which, despite its somewhat unsteady gait, are said to make it almost impossible to tip over. Its creators believe that flying machines could benefit from the robot, for example, if Mars helicopters like Ingenuity were equipped with such legs, they would be less likely to tip over and become unusable when landing on uneven ground.
Source: Caltech edu