Cat-like robot lands on all fours when thrown
If you're an emergency response worker who needs a robot to inspect a hazardous setting, it would be best if you could quickly just throw that bot in there. A new robot was designed with that in mind, as it automatically lands on all four of its wheels.
Known as AGRO (Agile Ground RObot), the prototype device was created by a team from the US Military Academy at West Point. Each one of its wheels pivots independently of all the others, and is independently powered by its own electric hub motor.
When the robot is thrown, an onboard IMU (inertial measurement unit) instantaneously detects that it's in freefall. This triggers an integrated PD (proportional-derivative) controller, which sets each of the wheels spinning at different angles and different speeds.
The resulting strategically delivered torque controls the pitch, roll and yaw angles of the robot, allowing it to land squarely on all four wheels. This not only ensures that the device lands upright, but also that the landing impact is distributed evenly, so the chances of damage are minimized.
AGRO can then take off into the burning building, collapsed tunnel, or whatever else it's exploring in advance of human rescue workers entering. Plans call for a future version to have bending legs with wheels on the ends (not unlike the latest ANYmal robot), which would help absorb landing impact and allow it to step over obstacles.
A paper on the research is being presented later this month via the online 2020 IEEE/RSJ International Conference on Intelligent Robots and Systems. The robot can be seen in action, in the video below.