The Array/HashBackWumpus Agent

A Hero for the Wumpus Environment

The ArrayBackWumpus agent and the HashBackWumpus agent offer some improvements over their ancestors. The most interesting improvement is its ability to keep track of the actions leading back to the entrance of the cave.

The strategy for generating a represantation of the environment

The agent invokes its superclasses' capabilities and enlarges them by adding the following information:

• Every field the agent visits is specially marked if the agent perceives a breeze and/or a stench.
• After every ten rounds the agent tries to find pits/the wumpus by checking for every field the following:
  • If a stench was percepted on the field and any three out of four of the surrounding fields are marked as not housing the wumpus the fourth field is marked as housing the wumpus.
  • If a breeze was percepted on the field and any three out of four of the surrounding fields are marked as not containing a pit the fourth field is marked as containing a pit.
• If a gold was found, the agent goes to the exit field to leave the cave.
• For every moving action the agent rememberst the antagonistic action which ultimately leads it back to the exit.

The strategy for generating a new action

The agent decides for its next action by combining the percepts for the current round with his knowledge about the environment. If the new methods are not able to find a satisfying action the reason capabilities of the ancestor is invoked.

• If the wayback vector ( i.e. a part of the agent's memory where it stores the actions that take it to the exit field ) contains actions and the agent should exit the cave ( indicated by a flag in the agent's memory that signals to 'go home' ) it walks towards the exit as long as actions remain in wayback.
• If the agent wants to leave the cave and the wayback vector is empty the agent has reached the exit-field and climbs out of the cave.
• If the wumpus is in any surrounding field and the agent is in possession of more arrows than surrounding fields exist that could house the wumpus the agent shoots in any of those directions and stores the other directions in the shooter vector ( i.e. another part of the agent's memory where it stores shooting actions it wants to take ).
• If the shooter vector has actions stored the agent shoots in one of the stored directions.
• If the reasoning capabilities of the ancestor have been invoked and it returns a move to a field that has been visited more than five times the agent starts its way back to the exit field to leave the cave.

A demonstration shows how the ArrayBackWumpus and the HashBackWumpus act in the same fashion with only choosing different directions.

Navigation:

• Back to the agent intro.
• Go to the Wumpus main page

Last modified: Sa. June 06 14:34:54 1997 by Christian Schwaiger

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