Information Technology Reference
In-Depth Information
The semantic of ADL is based on the mathematics structure which describes
the world statements. A action a is represented by a statement couple<
> in
ADL, and action a produces a statement
“
t
”
when it is executed at statement s.
The relations between a statement
s,t
φ
s
and a statement description
are
φ
.
The action template in ADL represents a set of possible actions, which is
described by four selectable clauses: Precond, prerequisite; Add and Delete, the
set of formulas added or deleted in relation
represented by a symbol
|=, denote as
s
R
on statement
t
; Update, a set of
relations which describe the functions how to transform from
.
The Multi-agent Planning means that one or more concurrent process of agent
search their respective targets in their respective planning space simultaneously.
In order to coordinate actions of different agents, we have to add partial
constraint between actions which may conflict with each other. The partial
constraint distributes in different agents, so there should be problem on judging
consistency in the partial constraint.
s
to
t
Algorithm 14.5
Consistency Checking of distributed partial order constraint.
calculate_transition_closure(
α
,
A
)
S
,
B
,
O
,
L
A
b
A
Input: planning
, constraint
,
i
j
(
)
T
<
.
1. send information to all agents to set temporal constraint O in its planning to read only
mode;
2. compute of local transitive closure
A
Output: transitive closure
(
)
α
<
T
A
of action
A
i
in agent α;
i
(
)
(
)
α
<
T
A
T
A
3.
=
<
i
i
(
)
T
A
4. let SET(agentn) be actions of the agent in
.
5. start a new thread for every nonempty SET(agentn)
6. {
7.
<
i
(
)
(
)
T
A
T
A
+ request (calculate_transition_closure(agentn,
SET(agentn) )
8. return.
9. }
10. after all subthreads return, return
=
<
i
<
i
(
)
T
<
11. demand of all agents to disable the read-only mode of constraint
.
In algorithm 14.6, the cooperation between agents involves two phases: task
assignment for every agent and subgoal planning of agent. Task assignment
i
