tingyingwu2010 / item-recovery-problem-alns

ALNS-based optimization technique for the "Item Recovery Problem", which is an optimization problem where an AUV with a maximum carry weight must visit multiple sites and recover items (i.e. bring them to a "base site") of different weights.

Item-Recovery-Problem-ALNS

This repository contains the source code for an ALNS-based optimization technique for the "Item Recovery Problem", which is an optimization problem where an AUV with a maximum carry weight must visit multiple sites and recover items (i.e. bring them to a "base site") of different weights.

Report: Item Recovery Problem An ALNS-based Approach

Problem Statement

The following image illustrates a possible scenario of this problem, where an AUV is used to recover items from an underwater cave.

The corresponding weighted graph for this scenario is shown in the following image. The items and their weights are shown to the right of each site.

Optimization Technique

• ALNS Heuristic

• Destruction Method

  • Random Position Removal

  

  • Random Position Swap

  

  • Random Subpath Removal

  

  • Remove Worst Subpaths

  

• 6 Repair Method

Results

Dataset used:

Instance	Sites	Sites With Items	Cargo Size	Graph Edges
1	40	36	2	101
2	45	39	9	112
3	50	44	4	66
4	55	47	7	111
5	60	49	3	140
6	65	61	6	98
7	70	63	3	169
8	75	62	5	193
9	80	68	4	185
10	85	72	9	170
11	90	72	9	228
12	95	86	9	236
13	100	91	10	156

Optimization Results:

Optimization Results:

Instance	Time Taken	Initial Cost	Best Cost
1	28 min	5258	3421
2	1 h	5724	2856
3	1.3 h	9254	6046
4	2.1 h	13280	8072
5	1.6 h	8098	3797
6	9.7 h	11614	7354
7	6.7 h	6028	2818
8	5.5 h	11614	7354
9	5.5 h	8474	4040
10	9.4 h	7966	5018
11	2.2 h	7560	3125
12	10.5 h	20932	6192
13	51.6 h	35946	23444

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