Large-Scale Storage/Retrieval Requests Sorting Algorithm for Multi-I/O Depots Automated Storage/Retrieval Systems
Table 4
Comparisons of unload times between EA and proposed method for small-scale problem.
N_r
Enumeration
Assignment
Diff1
T_NLa
CPU
T_NLb
CPU
N_SL
EMT
MinMT
7
177.8
0.016
177.8
0.006
2
0
1
0
7
188.2
0.004
188.2
0.003
0
0
0
0
7
181.8
0.015
181.8
0.003
3
1
1
0
7
244.8
0.016
244.8
0.004
2
1
0
0
7
208.2
0.015
208.2
0.004
0
0
0
0
7
193.2
0.016
193.2
0.004
3
0
2
0
7
168.6
0.016
168.6
0.003
3
1
1
0
7
249.6
0.015
249.6
0.003
2
0
1
0
7
167.4
0.016
167.4
0.004
3
0
2
0
7
203.0
0.015
203.0
0.002
2
1
0
0
8
213.0
0.043
213.0
0.004
2
0
1
0
8
219.8
0.045
219.8
0.004
0
0
0
0
8
301.4
0.054
301.4
0.004
2
1
0
0
8
210.4
0.035
210.4
0.007
4
1
2
0
8
238.4
0.047
238.4
0.002
3
1
1
0
8
220.8
0.062
220.8
0.016
0
0
0
0
8
246.4
0.046
246.4
0.016
3
2
0
0
8
275.8
0.047
275.8
0.002
0
0
0
0
9
243.2
0.330
243.2
0.008
3
1
1
0
9
230.6
0.323
230.6
0.004
4
2
1
0
9
255.6
0.323
255.6
0.002
2
0
1
0
9
285.8
0.329
285.8
0.004
0
0
0
0
9
212.0
0.312
212.0
0.006
3
2
0
0
9
253.4
0.329
253.4
0.003
3
1
1
0
9
240.4
0.342
240.4
0.002
0
0
0
0
9
201.8
0.338
201.8
0.003
2
1
0
0
9
266.0
0.316
266.0
0.003
0
0
0
0
9
247.8
0.311
247.8
0.005
3
2
0
0
9
239.8
0.326
241.2
0.004
3
1
1
1.4
10
229.8
3.385
229.8
0.016
3
2
0
0
10
292.8
3.229
292.8
0.003
0
0
0
0
10
232.4
3.245
232.4
0.016
3
1
1
0
10
349.0
3.198
349.0
0.002
2
1
0
0
10
271.0
3.213
271.0
0.002
3
1
1
0
10
332.4
3.229
332.4
0.002
2
1
0
0
10
291.6
3.230
291.6
0.015
3
2
0
0
10
272.6
3.229
272.6
0.002
2
1
0
0
10
280.8
3.182
280.8
0.015
0
0
0
0
10
241.8
3.244
241.8
0.012
3
0
2
0
10
251.6
3.354
251.6
0.015
3
1
1
0
11
317.4
49.134
317.4
0.016
4
2
1
0
11
243.4
51.510
243.4
0.016
3
1
1
0
11
286.2
45.344
286.2
0.015
2
1
0
0
11
267.8
41.389
267.8
0.016
3
1
1
0
11
283.2
48.496
283.2
0.015
3
1
1
0
11
267.8
42.226
267.8
0.016
3
1
1
0
11
283.2
49.931
283.2
0.015
3
1
1
0
11
294.8
40.909
294.8
0.015
2
1
0
0
11
300.4
44.486
302.0
0.015
3
1
1
1.6
Note. Five-layer double row shelf with 15 I/O depots, N_r: number of S/R requests; T_NL: no-load travel time of stacker (sec); CPU: computation time (sec); N_SL: the number of subloops; EMT: the equivalent merging times of subloops; MinMT: the minimum cost merging times of subloops; Diff1 = T_NLa − T_NLb.
