Korean researchers have developed a four-legged robot capable of traveling on rough and uneven surfaces made of steel. The robot with magnetic feet can climb up walls and freely move around on ceilings to help human workers inspect large facilities such as vessels, bridges, and transmission towers. It is also expected to contribute to automated repairs.
The work of a research team led by Professor Park Hae-won, a mechanical engineering professor at the Korea Advanced Institute of Science & Technology (KAIST), was recently published in the journal Science Robotics.
Researchers are making efforts to develop robots that can access areas that are too dangerous for humans. There are climbing robots that mimic caterpillars or quadrupedal walking robots with feet. However, both robots have their shortcomings. Climbing robots use wheels, making it difficult to move on surfaces with steps or bumps. Plus, although quadrupedal robots can move around easily on those surfaces, the speed is significantly slow.
However, the research team has developed an agile four-legged robot capable of performing various movements on rough and uneven surfaces with speed. The robot can move at a speed of 70 centimeters per second on vertical walls and 50 centimeters per second on ceilings. This is faster than the existing robot, with a speed of 67 centimeters per second which can’t move on ceilings.
The secret has to do with its magnetic feet. This magnet foot was made using a magnet that can turn electromagnetic force on and off and a magneto-rheological elastomer that increases friction. It can turn on and off adhesive force quickly. And it is highly adhesive on uneven surfaces. The weight of the magnet foot is only 169 grams, but it has a vertical adsorption force of 535 N, and a friction force of 445 N. 535N is converted to 54.5 kilograms. This means it is attached to the metal plate even if 54.5kg of force is vertically applied.