Newsgroups: comp.robotics
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From: jr@faber.ka.sub.org (Juerg Reinhart)
Subject: When is planning good?
Date: Tue, 15 Feb 1994 08:42:13 GMT
Message-ID: <CL9C6E.3J0@faber.ka.sub.org>
Organization: -
Lines: 32

Traditional agent architectures are of the plan-then-execute type
augmented by a monitor to detect and handle unexpected situations. An
alternative way is to seperate the agent's goals and to construct a
task-achieving subsystem for each of them (e.g., Brooks' subsumption
architecture).  Each subsystem is reactive, it is connected to the
sensors and actuators of the agent.

It is quite astonishing how many demanding problems purely reactive
agents of the latter kind can solve without any planning though the
problem is to assure convergence. I wonder when the need for planning
arises given a basis of robust, reactive behaviors -- especially since
plans tend to be brittle in unstable environments. I would like to ask
YOU: When should an agent switch from pure reaction to anticipation?
In which situation is it useful to guide behavioral decisions by a
plan?

And if you find plans useful in one way or another: Should the plan be
detailed so that the agent can follow it word for word as long as
expectations meet with reality? Or should the plan be used as a
guideline, a rough sketch of what should be done until the agent gets
in the whirl of unpredictable circumstances?

If there is enough interest I will post a summary of the responses I
received. 

Thank you for your attention and help

- JR




