How do you make robots walk on Mars?This is a serious challenge

From traveler The rover that landed on Mars in 1997 to perseverance, Landing in February, The robots of the Red Planet have a common feature: wheels.Rolling is more stable and energy efficient than walking, even if the robots on the planet still do Hard to masterAfter all, NASA would hate its very expensive Mars explorer toppling and flail like a tortoise on its back.

The problem with the wheels, however, is that they restrict the rover’s whereabouts: in order to explore the complex Martian terrain like steep hills, you need to evolve the kind of legs provided for animals on Earth.Therefore, a group of scientists from the Swiss Federal Institute of Technology Zurich and the Max Planck Institute for Solar System Research in Germany have been playing around Small quadruped robot call Space book, Designed to imitate the antelope known as the springbok.

True to its name, the springbok in real life Jumping around in the African desert, Perhaps to confuse predators. The original concept of the robot launched in 2018 was actually to make it jump on the surface of the moon, just like astronauts do when the moon’s gravity is weak. This may apply to our satellites, where the terrain is relatively flat, but on Mars, considering the complex terrain-full of sand, rocks, and steep slopes, it may be too risky. So now researchers are modifying its limbs and gait to see if it can handle more cruel scenery.

In these new experiments, the team programmed SpaceBok to make its gait more traditional and less flexible. Specifically, the researchers wanted to compare two gaits: one is a “static” gait, in which at least three limbs are in contact with the ground at any given time, and the other is a “dynamic” gait, in which more than one limb can be Leave the ground immediately. The former is more organized, but the latter is more efficient because it allows the robot to move faster.

The researchers also equipped SpaceBok with two types of feet: point feet and flat feet. The pointed feet have a small surface area, a bit like the hoof of a real springbok. In contrast, a flat foot is actually a flat, rotating circle that bends at an angle when the foot is in contact with the ground. Think these are more like snowshoes than hooves. Or really, they are like snowshoes with cleats, because they are covered with protrusions that help the feet catch the ground.

Once the researchers had the asynchronous state and foot configuration that they could use to customize the robot, they placed it in a huge inclined sandbox filled with materials similar to the soil found on Mars. In this way, they can test whether any of these configurations allows the robot to climb up to a 25-degree plane. By monitoring the energy usage of the robot, they can quantify the efficiency of each configuration of gait and foot.

in a New preprint Describe the work, which has been accepted for publication by the journal Live robot, They showed that the machine can dexterously and effectively climb the simulated Martian hills without tipping over. Hendrik Kolvenbach, a roboticist at ETH Zurich, the lead author of the study, said: “We want to prove that these dynamically working systems can actually walk on Martian beaches.” “This is a project with great potential for the future now. technology.”