ARGO (Agile Ground Robot) is a robot that has the ability to land like a cat developed by the Robot Research Center of the US Army Academy. Robots are useful when exploring places that are too dangerous to humans, such as a building with a fire or a collapsed tunnel. However, in order to increase the ability to tackle the negatives required for such a robot, it is given the ability to disperse the impact when landing with four feet like a cat and falling.
The characteristic of ARGO is its legs. Using an in-wheel motor, it is possible to control the rotation of the wheels before and after, left and right, and up and down. You can also rotate the wheel 90 degrees to bend it almost at a right angle. When the controller is activated, the built-in inertial measurement unit immediately detects when the body is tilted in the air by throwing. The wheel is rotated in the same direction by rotating the wheel located diagonally at an angle of 45 degrees inward to create torque to keep the body horizontal.
With this torque, ARGO lands so that all four wheels are at right angles, so it not only distributes the impact evenly when landing, but also reduces the impact itself by 20%. In addition, if the rotation speed is less than 60 rpm, the posture can be restored, so if there is sufficient height, the probability of falling in the opposite direction to the horizontal is almost zero.
The research team said that in theory, ARGO can rotate 22.5 degrees left and right in 250 milliseconds, and there is a possibility to further improve it by controlling the angle of each wheel in real time. The potential for wheeled robots used in the air can be said to be substantial. Something that can be useful for robots that operate on ramps or stairs, or robots that fall from aircraft. It can also be helpful when dropping military vehicles from the air by controlling the rotation during dropping so that the parachute cord is not entangled. Related information can be found here .