Now, ‘Salto’ the jumping robot navigates an agility course with ease

Small robots are really great for a lot of things like running around in places where larger robots or humans can’t fit. The robots might be useful in the search-and-rescue missions

Back in 2016, the researchers at the University of California, Berkeley, first created the robot called Salto (saltatorial locomotion on terrain obstacles) and revealed its high-flying capabilities. Now the team has equipped the robot a slew of new skills, giving it the ability to bounce in a place like a pogo stick and jump through obstacle courses like an agility dog.

Powered by a radio controller, Salto can even take short jaunts around Berkeley campus. They improved the robot’s skill with the hope that Salto will promote the development of small, agile robots who can jump from rubber to help in the search and rescue operation.

“In a disaster scenario, where people might be trapped under rubble, robots might be really useful at finding the people in a way that is not dangerous to rescuers and might even be faster than rescuers could have done unaided,” said UC Berkeley robotics graduate student Justin Yim. “We wanted Salto to not only be small but also able to jump really high and really quickly so that it could navigate these difficult places.”

Yim works with Ronald Fearing, an electrical engineering and computer sciences professor at UC Berkeley, whose Biomimetic Millisystems Lab explores how the mechanics of animal movement can be applied to create more agile robots.

Researchers described the robot’s new skills at the 2019 International Conference on Robotics and Automation in Montreal on Tuesday.

The solo, powerful foot of the robot is modeled after those of the galago, or Senegalese bush baby. The small, tree-dwelling primate’s muscles and tendons store energy in a way that gives the spry creature the ability to string together multiple jumps in a matter of seconds.

nd by linking a series of quick jumps, Salto can navigate complex terrains like a pile of debris that might be impossible to cross without jumping or flying.

“Unlike a grasshopper or cricket that winds up and gives one jump, we’re looking at a mechanism where it can jump, jump, jump, jump,” Fearing said. “This allows our robot to jump from location to location, which then gives it the ability to temporarily land on surfaces that we might not be able to perch on.”

Three years ago, the design team of Salto proved how a robot could take a leap, and then immediately spring higher by bouncing off the wall. Since then, Yum has been making efforts to create sophisticated control systems that let Salto master increasingly complex tasks, like bouncing in place, navigating an obstacle course or following a moving target.

In addition, the jumping robot now has equipped with the new technology that allows it to “feel” its own body, telling it what angle it is pointing and the bend of its leg. Without this capability, Salto is limited to a room in Berkeley’s engineering building, where the motion capture cameras track its exact angle and position and send that data back to the computer. The computer then rapidly crunches the numbers to tell Salto how to angle itself for its next leap.

Now, the robot is able to make these calculations for itself, as Salto has a sense of itself and its own motion. This allows Yim to take the robot outside and use a joystick and radio controller to tell it where to go.

“Motion capture is great for getting the robot to jump around in a controlled environment really precisely, and it gives us tons of really great data,” Yim said. “The problem is, we can’t take this out and use it anywhere else because it takes a long time to set up all of these cameras.”

“We really wanted to be able to take the robot out and go jump around. And to do that, we needed the robot to be able to compute where it is and what it is doing – just with the computer on top of its own body.”

Salto can now go out for walks on the Berkeley campus, where it has successfully maneuvered over sidewalks, brickwork, and grass. The mathematical models that make this possible for Salto also could be generalized to control the motion of other kinds of robots, Yim said.

“By understanding the way that these dynamics work for Salto, with its mass and size, then we can extend the same type of understanding to other systems, and we could build other robots that are bigger or smaller or differently shaped or weighted,” Yim said.

In the future, Fearing hopes to continue to explore the possibilities for hopping robots.