pddl

问题 I am trying to solve a Pacman-style problem with a planner, using PDDL. I assume there are many food in the given map. I use exists to check if here is any other food in the map, but it does not work; why is that? Here is my problem file: (define (problem pacman-level-1) (:domain pacman_simple) ;; problem map ;; | 1 | 2 | 3 | ;; -|---|---|---| ;; a| P | G | F | ;; b| _ | _ | _ | ;; |---|---|---| (:objects a1 a2 a3 b1 b2 b3 - cell pacman - pacman ghost - ghost food1 - food food2 - food nofood

问题 I am trying to solve a Pacman-style problem with a planner, using PDDL. I assume there are many food in the given map. I use exists to check if here is any other food in the map, but it does not work; why is that? Here is my problem file: (define (problem pacman-level-1) (:domain pacman_simple) ;; problem map ;; | 1 | 2 | 3 | ;; -|---|---|---| ;; a| P | G | F | ;; b| _ | _ | _ | ;; |---|---|---| (:objects a1 a2 a3 b1 b2 b3 - cell pacman - pacman ghost - ghost food1 - food food2 - food nofood

问题 I am both using durative actions and trying to be able to clear a predicate over all elements of a certain type. See below. Is this possible? If so, does anyone know the correct syntax? Thanks! (:durative-action init :parameters (?r - robot) :duration ( = ?duration 1) :condition (and (at start (robot_uninitialized ?r)) (at start (robot_free ?r)) ) :effect (and (at start(not(robot_free ?r))) (at end (assign (robot_on_fastener_number_in_sequence) 1)) (at end (not(robot_uninitialized ?r))) (at

问题 I am both using durative actions and trying to be able to clear a predicate over all elements of a certain type. See below. Is this possible? If so, does anyone know the correct syntax? Thanks! (:durative-action init :parameters (?r - robot) :duration ( = ?duration 1) :condition (and (at start (robot_uninitialized ?r)) (at start (robot_free ?r)) ) :effect (and (at start(not(robot_free ?r))) (at end (assign (robot_on_fastener_number_in_sequence) 1)) (at end (not(robot_uninitialized ?r))) (at

问题 I've written a domain and a test problem in PDDL, but apparently the graphplan implementation can't find a plan. Here's the domain: (define (domain aperture) (:requirements :strips :typing :negative-preconditions) (:types cube hallway room - location ) (:predicates (at ?l - location) (has ?c - cube) (connected ?l1 - location ?l2 - location) (in ?c - cube ?l - location) ) (:action enter :parameters (?h - hallway ?r - room) :precondition (and (connected ?h ?r) (connected ?r ?h) (at ?h) (not (at

问题 This might be a totally naive question, but i am interested to know the particular reasons. Why was PDDL developed in the first place? Why could we not do the reasoning using First Order Logic? 回答1: Efficiency In Solving Using a more specific language to express your problem makes it possible to apply more specific algorithms to solve them. From a theoretic point of view FOL is undecidable while most flavors of PDDL are still decidable, because PDDL can only express planning problems. And e.g

问题 how can i be sure that the plan, computed by the fast forward planner, is the best of all the possible plans?! Does exist an automatic tool to solve this problem?! thanks a lot! 回答1: If I don't remember it wrong FF is not an optimal planner so you can't be sure if the generated plan is optimal. On the other side FF is fast in generating "good enough" solutions in contrast to optimal planners ( cpt4 , bjolp , ecc...) which provide optimal plans but much more slowly than satisficing planners.

问题 This might be a naive question, but i am really interested to know why logic was developed to be used in AI. In particular, what was the need to develop first order logic and PDDL in AI, if we could do the programming using simple atomic representation of states? Again, I realize this is a really basic question!! 回答1: So your question is about: why do we program/model on a first-order level instead of a propositional level? Simply because it is more concise. You can make propositions like