Encodings for asprilo environments
The encodings are grouped in two directories
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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 putdown2 without shelf representation3 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
- compatibility is achieved by combing files with same (or similar) attributes
- Keyword action precedes files containing action theories
- Example action-M.lp, action-MPP.lp, action-MPP.iclp, etc.
- 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 strategy precedes files specifying strategies
- Example strategy-MPPD.lp
- Some strategies may not work with all layouts!
- Keyword highways precedes files specifying conditions for places belonging to highways
- Example highways.ilp, highways.lp,
- Keyword optimization precedes files specifying objective functions
- Example optimization.ilp, optimization.lp
- experimental feature
- Keyword heuristic precedes files specifying heuristics with clingo's
#heuristicdirective - Example heuristic.ilp, heuristic.lp
- experimental feature
- files preceded with show provide
#showstatements for use with terminal output
- Some warehouse layouts merged with orders can be found in the directory
examplesMany 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 commandhead -n1to 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
- This is also done with script
- 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