Meet Cassie, the bipedal robot who taught itself how to walk

So, what is reinforcement learning? It's a training technique that teaches AI complex behavior by trial and error. In other words, the robot tries to walk and learns from its mistakes whenever it fails, similar to how babies learn how to walk. But before Cassie could stumble around in the real world, the team started with a simulation of the robot in a virtual world. Using a training environment called MuJoCo, the simulated robot referenced a large library of possible movements and learned how to apply them. The team then ran a second simulation, called Matlab SimMechanics, to test the robot in simulated real-world conditions.