Robots playing soccer is nothing new. Most soccer robots are bipedal. Hybrid Robotics have come up with a reinforcement learning framework that enables quadrupedal robot to play the game, turning them into pretty effective goalkeepers.
As the researchers explain, their reinforcement learning framework:
contains multiple control policies for distinct locomotion skills, which can be used to cover different regions of the goal. Each control policy enables the robot to track random parametric end-effector trajectories while performing one specific locomotion skill, such as jump, dive, and sidestep. These skills are then utilized by the second part of the framework which is a high-level planner to determine a desired skill and end-effector trajectory in order to intercept a ball flying to different regions of the goal.