Method for storing and updating belief distributions

edit

In my domain there is a robot and dynamic objects. I am trying to maintain a map similar to an occupancy grid. It would store belief distributions (probability distribution representing where an object is located) of the objects in the world. This would be updated with their transition models. For example, if the robot is on one side of the room and an object is moving on the other side of a room, the robot can't see it, but it has an idea of how that object moves in the world, so it can still update its its belief distribution. Is there a package out there that does something like this? I haven't been able to find one.