An Application of Self-Organizing Map for Multirobot Multigoal Path Planning with Minmax Objective

In this paper, Self-Organizing Map (SOM) for the Multiple Traveling Salesman Problem (MTSP) with minmax objective is applied to the robotic problem of multigoal path planning in the polygonal domain. The main difficulty of such SOM deployment is determination of collision-free paths among obstacles that is required to evaluate the neuron-city distances in the winner selection phase of unsupervised learning. Moreover, a collision-free path is also needed in the adaptation phase, where neurons are adapted towards the presented input signal (city) to the network. Simple approximations of the shortest path are utilized to address this issue and solve the robotic MTSP by SOM. Suitability of the proposed approximations is verified in the context of cooperative inspection, where cities represent sensing locations that guarantee to “see” the whole robots’ workspace. The inspection task formulated as the MTSP-Minmax is solved by the proposed SOM approach and compared with the combinatorial heuristic GENIUS. The results indicate that the proposed approach provides competitive results to GENIUS and support applicability of SOM for robotic multigoal path planning with a group of cooperating mobile robots. The proposed combination of approximate shortest paths with unsupervised learning opens further applications of SOM in the field of robotic planning

A review of the Tabu Search Literature on Traveling Salesman Problems

The Traveling Salesman Problem (TSP) is one of the most widely studied problems inrncombinatorial optimization. It has long been known to be NP-hard and hence research onrndeveloping algorithms for the TSP has focused on approximate methods in addition to exactrnmethods. Tabu search is one of the most widely applied metaheuristic for solving the TSP. Inrnthis paper, we review the tabu search literature on the TSP, point out trends in it, and bringrnout some interesting research gaps in this literature.

An application for handheld devices to solve capacitated vehicle routing problems

His paper presents an application for handheld devices (smartphones and tablets), to solve ca-pacitated Vehicle Routing Problems. The application implements a visual interactive solution method that integrates the insight and experience of the scheduler, and the power and precision of the heuristics, in an interactive environment. The solution method was implemented to make use of the interesting features and services of the current handheld devices. Results show that despite the restrictions on the processing power of these devices, their functionalities are very interesting to implement visual interactive methods, allowing the common user to easily solve vehicle routing problems

A vehicle routing model with split delivery and stop nodes

In this work, a new variant of the Capacitated Vehicle Routing Problem (CVRP) is presented where the vehicles cannot perform any route leg longer than a given length L (although the routes can be longer). Thus, once a route leg length is close to L, the vehicle must go to a stop node to end the leg or return to the depot. We introduce this condition in a variation of the CVRP, the Split Delivery Vehicle Routing Problem, where multiple visits to a customer by different vehicles are allowed. We present two formulations for this problem which we call Split Delivery Vehicle Routing Problem with Stop Nodes: a vehicle flow formulation and a commodity flow formulation. Because of the complexity of this problem, a heuristic approach is developed. We compare its performance with and without the stop nodesSplit delivery vehicle routing problem, Stop node, Granular neighborhood, Tabu search

Cuckoo search algorithm: A plastic waste collection example

Gezgin satıcı ve araç rotalama problemleri polinom zamanda çözümlenemediği için NP-Zor sınıfında yer alırlar. Veri sayısı az olan küçük problemler için kesin matematiksel yöntemler geliştirilmiş olsa da büyük problemler için bu yöntemlerle çözüme ulaşmak bazen olanaksız bazen de zaman karmaşıklığı kabul edilemeyecek kadar büyük olmaktadır. Bu nedenle araştırmacılar daha çok sezgisel algoritmalar üzerindeki çalışmalara yoğunlaşmışlardır. Bu çalışmada, sezgisel algoritmalar arasında yer alan guguk kuşu algoritması gezgin satıcı problemine uygulanmıştır. Ayrıca, elde edilen çözümlerin 2-opt yerel arama algoritması ile çözüm kalitesi geliştirilmiştir. Literatürde yer alan, Sırbistan’ın Niş şehrindeki 20 bölgeye konumlandırılmış plastik atık konteynerlerinde yer alan atıkların kamyonlarla toplanmasına ilişkin problem ele alınmış, literatürdeki çözüm, tasarruf algoritması çözümü ve önerilen yöntem ile elde edilen çözüm karşılaştırılmıştır. Literatürde yer alan çözümün ve Tasarruf Algoritması çözümünün rota uzunluklarının sırası ile 1507 km, 1074 km olduğu hesaplanmıştır. Önerilen çözümün ise 10 çalıştırmanın en iyi sonucu olarak rota uzunluğunu 1069 km olarak elde ettiği görülmüştür. Önerilen çözümün, hem Tasarruf hem de literatürde yer alan çözüm sonuçlarından daha üstün olduğu görülmektedir

A vehicle routing model with split delivery and stop nodes

In this work, a new variant of the Capacitated Vehicle Routing Problem (CVRP) is presented where the vehicles cannot perform any route leg longer than a given length L (although the routes can be longer). Thus, once a route leg length is close to L, the vehicle must go to a stop node to end the leg or return to the depot. We introduce this condition in a variation of the CVRP, the Split Delivery Vehicle Routing Problem, where multiple visits to a customer by different vehicles are allowed. We present two formulations for this problem which we call Split Delivery Vehicle Routing Problem with Stop Nodes: a vehicle flow formulation and a commodity flow formulation. Because of the complexity of this problem, a heuristic approach is developed. We compare its performance with and without the stop node

Solving a static repositioning problem in bike-sharing systems using iterated tabu search

In this paper, we study the static bike repositioning problem where the problem consists of selecting a subset of stations to visit, sequencing them, and determining the pick-up/drop-off quantities (associated with each of the visited stations) under the various operational constraints. The objective is to minimize the total penalties incurred at all the stations. We present an iterated tabu search heuristic to solve the described problem. Experimental results show that this simple heuristic can generate high quality solutions using small computing times.postprin

Routing Unmanned Aerial Vehicles While Considering General Restricted Operating Zones

U.S. military forces employ unmanned aerial vehicles (UAVs) to conduct intelligence-gathering missions worldwide. For a typical mission, commanders may task UAV operators to gather imagery on 100 or more sites or targets. UAV operators must quickly prepare mission plans that meet the needs of their commanders while dealing with real-world constraints such as time windows, site priorities, imagery requirements, UAVs with different capabilities (i.e. imagery equipment, speed, and range), and UAVs departing from different bases. Previous AFIT research provided the UAV Battlelab with a tool, AFIT Router, for generating high-quality routes to aid mission planning. This research enhances the AFIT Router by providing the ability to define general restricted operating zones and to build routes that consider these zones. This research also examines and compares a probabilistic tabu search heuristic and two reactive tabu search heuristics for solving vehicle routing problems

Thirty years of heterogeneous vehicle routing

It has been around thirty years since the heterogeneous vehicle routing problem was introduced, and significant progress has since been made on this problem and its variants. The aim of this survey paper is to classify and review the literature on heterogeneous vehicle routing problems. The paper also presents a comparative analysis of the metaheuristic algorithms that have been proposed for these problems