asprilo

Encodings for asprilo environments

Conventions

The encodings are grouped in two directories

mppd contains fine-grained encodings dealing with move, pickup, putdown, and deliver actions and distinguish robots, shelves, stations, etc and take robots carrying shelves into account for collision protection
xapf contains encodings addressing more abstract problems, like MAPF, TAPF, GTAPF, etc

We adopt the following conventions:

letters M, P, P, and D stand for actions move, pickup, putdown, and deliver
digits 2 and 3 indicated the arity of actions pickup and putdown
- ~~2 without shelf representation~~
- ~~3 with shelf representation~~
letters 0, r, and q indicate the treatment of order lines during delivery
- This applies to all files preceded with goal- in the mppd setting
file extensions lp, ilp, clp, and iclp stand for regular, incremental, constraint, and incremental constraint logic programs
- since integer variables are uses for product quantities and robot and shelf positions, I sometimes need auxiliary letters to disambiguate, eg a capital C stands for both usages, a mere b is like a c but applied to positions
omissions of such indicators are treated like wild-cards

Keyword goal precedes files fixing goal conditions and in particular what constitutes a delivery
as mentioned above, letters 0, r, and q indicate the treatment of order lines during delivery

Keywords input and output precede files converting
- asprilo instances to the format used in action theories and
- the resulting plan into the format of asprilo
Example input.lp, output-M.lp, output-MPPD.lp

Keyword goal precedes files specifying goal conditions
Goals counting quantities are indicated with letter Q and include the corresponding encoding for quantities
Goals with ending 0 and r indicate whether all products belonging to an order are processed simultaneously (0) or at rate r (default is 1)
Example goal-D-0.clp, goal-D-r.ilp, goal-M.lp, goal-D-q.lp

Keyword quantities precedes files dealing with amounts of products
Similarly letter q indicates quantities; now used with goals
Attention This needs a constraint ASP solver like clingcon
Example quantities.lp, quantities.clp, quantities.ilp, quantities.iclp

Keyword highways precedes files specifying conditions for places belonging to highways
Example highways.ilp, highways.lp,

Keyword heuristic precedes files specifying heuristics with clingo's #heuristic directive
Example heuristic.ilp, heuristic.lp
experimental feature

files preceded with show provide #show statements for use with terminal output

Some warehouse layouts merged with orders can be found in the directory examples Many of them contain (uncommented) calls in their header
Here are some exemplary calls
- clingo action-MPP.lp strategy-MPP.lp goal-D-0.lp show.lp examples/x4_y4_n16_r2_s3_ps1_pr2_u4_o2_N1.lp -c horizon=8
To produce plans ready for asprilo use clingo option
- --outf=0 -V0 --out-atomf=%s. together with UNIX command head -n1 to strip off the trailing (UN)SATISFIABLE
- or the included script clingo1facts (all facts in one line)
Sometimes it is also nice to see an answer set as a single column, as done with clingo option --out-ifs='\n'
- This is also done with script clingo2facts

Examples connecting to asprilo on the command-line
- clingo action-MPP.lp goal-D-0.lp examples/x4_y4_n16_r2_s3_ps1_pr2_u4_o2_N1.lp -c horizon=8 output-MPPD.lp --outf=0 -V0 --out-atomf=%s. | head -n1 | asprilo-visualizer
asprilo is available at github