Action Description Language

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The Action Description Language ( ADL ) is a planning system especially for robots . It is considered a further development of STRIPS .

The purpose of planning language is to represent certain conditions in the environment and based on this to automatically determine a sequence of actions that lead to a desired goal. A goal is a certain partially specified state. In order for an action to be carried out, certain preconditions must be met; after execution, the action has effects that change the environment. The environment is described using certain predicates, which are either fulfilled or not fulfilled.

In contrast to STRIPS, the principle of the "open world" applies to ADL: What does not occur in the state is unknown. Negative literals and disjunctions are also allowed.

example

As an example, one can imagine the problem of air freight transport, in which certain goods have to be transported from one airport by plane to another airport and the planes have to be loaded and unloaded. The actions required would be loading , unloading, and flying ; The predicates In (c, p) and In (x, a) could be used to express whether a cargo c is located in an aircraft p and whether an object x is located at an airport a .

The actions could then be defined as follows: 

 Aktion: beladen, (c: Fracht, p: Flugzeug, a: Flughafen),
 Vorbed.: bei (c, a) ^ bei(p, a)
 Effekt: bei (c, a) ^ in(c, p)

 Aktion: entladen (c : Fracht, p : Flugzeug, a : Flughafen),
 Vorbed : In (c, p) ^ Bei (p, a)
 Effekt : Bei (c, a) ^ ¬In(c, p)

 Aktion fliegen(p : Flugzeug, von : Flughafen, zu : Flughafen),
 Vorbed : Bei(p, von) ^ (von ≠ zu)
 Effekt : ¬Bei(p, von) ^ Bei(p, zu)

literature

  • Stuart Russell, Peter Norvig: Artificial Intelligence: A Modern Approach, August 2004, Pearson Studies, ISBN 3-8273-7089-2 (German translation of the 2nd edition), pp. 469–471