» ASP Competition | |
|
Hydraulic System Planning - 1Problem descriptionA simplified version of the hydraulic system on a space shuttle consists of a directed graph, G, such that:
Tanks can be full or empty. Valves can be open or closed. Some of the valves can be stuck in the close position. A node of G is called pressurized in state S if it is a full tank or if there exists a path from some full tank of G to this node such that all the valves on the edges of this path are open. We assume that in a state S a shuttle controller can open a valve V2 corresponding to a directed link <N1,N2> only if N1 is pressurized and not stuck. Problem: Given a graph G together with an initial state and a jet j, a shuttle controller needs to find a shortest sequential plan to pressurize j. Write a program which automates this process. We assume that your program will contain the following input and output atoms: Input atomsThe graph should be described by the collection of ground atoms:
The state description uses atoms:
The goal to achieve:
Output atomsA sequence of atoms of the form switchon(v, t). which means an action to open valve v at time step t, where t is an integer. The switches should occur at consecutive time steps beginning from 0. (Note that, in contrast to the original description, the order of atoms in the output does not matter.) Authors: Michael Gelfond, Ricardo Morales and Yuanlin Zhang. |