The MIT engineers developed Cheetah 3 robot can now climb stairs and step over obstacles without the help of cameras and quickly recover its balance when suddenly pulled or moved. The upgrade in the robot includes the changes in its hardware that allows it to stretch and twist. The upgrade is involved a new design that helps the robot to move across rough terrain and through obstacles without relying on vision.

“There are many unexpected behaviors the robot should be able to handle without relying too much on vision,” said Sangbae Kim, Associate Professor and robot’s designer at the Massachusetts Institute of Technology (MIT) in Boston.

The Cheetah 3 robot dependent on two algorithms: a contact detection algorithm and a model-predictive control algorithm. The first algorithm that helps the Cheetah 3 robot figure out when it should be swinging its leg and when it should step down. It does so use data from gyroscopes, accelerometers and the joint positions of the Cheetah’s legs and second algorithm predicts how much force the Cheetah’s leg should apply once it has committed to a step. These two algorithms are designed to make these calculations for each leg every 50 milliseconds, or 20 times per second.

If the robot unexpectedly steps on a wooden block, its body will suddenly tilt, shifting the angle and height of the robot. That data will immediately feed into calculating the three probabilities for each leg, which the algorithm will combine to estimate whether each leg should commit to pushing down on the ground, or lift up and swing away in order to keep its balance — all while the robot is virtually blind.

“Vision can be noisy, slightly inaccurate, and sometimes not available, and if you rely too much on vision, your robot has to be very accurate in position and eventually will be slow. So we want the robot to rely more on tactile information. That way, it can handle unexpected obstacles while moving fast,” Kim said.

According to the MIT press release, this Cheetah 3 robot would be helpful for missions in dangerous or inaccessible environments, such as exploring disaster zones. While the Cheetah 3 robot is effectively blind and is designed to use “blind locomotion”, the Cheetah 3 robot now has a camera to give visual feedback of its surroundings. Researcher Sangbae Kim’s team Researchers will present the robot’s vision-free capabilities in October at the International Conference on Intelligent Robots, in Madrid.