Planning

In real world the planning is difficult. Because of the environment is:

1. Stochastic
2. Multi-agent
3. Partial observability

Instead of planning in the world states, we planning it in the belief state.

For example:

Here is a simple diagram with 8 total states. There are three actions, moving right, moving left and suck dirt.

If the robot’s sensor break down, it does not know which location it is. Then it becomes a partially observed world.

This is the belief state. We start off in the center (8 possible states). But if we execute actions, we could gain knwoledge about the world even without sensoring it.

We now know more about the world even without observering anything.

Noticing that we could reaches the goal without ever observing the world. Plans like that care called conformant Plans.