CS541 Homework 1

Due: Sept. 13

This week, you will run the UCPOP planner and define a simple planning domain. The UCPOP planner is available from the CS 541 home page.

The domain we will define is a simple trucking domain, which has three types of objects: trucks, cities and packages. Trucks are used to transport packages from one city to another. Define a UCPOP domain with three operators: "drive", "load" and "unload". A truck can go directly from any city to any other city with a "drive" operator. Each truck can transport just one package at a time from one city to another. To load a package in a truck, the truck must be empty and the truck and package must both be at the same city. When you unload a package from a truck, it becomes empty again.

1. Define this planning domain in UCPOP.
2. Test your domain on a simple problem that requires moving a package from one location to another. Make sure that the package is not in two cities at the same time.
3. Turn in a print out of your domain, initial state, goal state, and trace of a successful run.
4. Test your domain on problems that require moving one, two and three packages from one location to another. Use the statistics reported by UCPOP to see how long the planner takes for each of these problems.
5. Remove the restriction that a truck can only transport one package at a time. How does it affect UCPOP's performance for the different numbers of packages?

Hints:

Because there is no search control, even the most trivial problem may exceed the search limit. Start with the smallest possible examples to debug your operators and gradually work up to more complex problems. If the problems are still to hard, simplify the operators as much as possible. For example, you can eliminate the locations within rooms and the operators for moving to locations.

Add your new operators to this domain one at a time and test them as you go. It is hard to debug planning domains, so it is easier to write the operators carefully and test them as you go.