Before revision:  This is done by embedding the changes in the environment' s state in a novel observation space and a reward function formulation that reinforces spatially aware obstacleavoidance maneuvers .
After revision:  This is done by embedding the changes in the environment' s state in a novel low-dimensional observation space. It also uses a novel reward function to positively reinforce velocities that move the robot away from the obstacle's heading direction leading to significantly lower number of collisions .