scholarly journals An Integrated Approach to Goal Selection in Mobile Robot Exploration

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1400 ◽  
Author(s):  
Miroslav Kulich ◽  
Jiří Kubalík ◽  
Libor Přeučil

This paper deals with the problem of autonomous navigation of a mobile robot in an unknown2D environment to fully explore the environment as efficiently as possible. We assume a terrestrial mobilerobot equipped with a ranging sensor with a limited range and 360º field of view. The key part of theexploration process is formulated as the d-Watchman Route Problem which consists of two coupledtasks—candidate goals generation and finding an optimal path through a subset of goals—which aresolved in each exploration step. The latter has been defined as a constrained variant of the GeneralizedTraveling Salesman Problem and solved using an evolutionary algorithm. An evolutionary algorithmthat uses an indirect representation and the nearest neighbor based constructive procedure was proposedto solve this problem. Individuals evolved in this evolutionary algorithm do not directly code thesolutions to the problem. Instead, they represent sequences of instructions to construct a feasible solution.The problems with efficiently generating feasible solutions typically arising when applying traditionalevolutionary algorithms to constrained optimization problems are eliminated this way. The proposedexploration framework was evaluated in a simulated environment on three maps and the time needed toexplore the whole environment was compared to state-of-the-art exploration methods. Experimentalresults show that our method outperforms the compared ones in environments with a low density ofobstacles by up to 12.5%, while it is slightly worse in office-like environments by 4.5% at maximum.The framework has also been deployed on a real robot to demonstrate the applicability of the proposedsolution with real hardware.

Robotica ◽  
2021 ◽  
pp. 1-26
Author(s):  
Meng-Yuan Chen ◽  
Yong-Jian Wu ◽  
Hongmei He

Abstract In this paper, we developed a new navigation system, called ATCM, which detects obstacles in a sliding window with an adaptive threshold clustering algorithm, classifies the detected obstacles with a decision tree, heuristically predicts potential collision and finds optimal path with a simplified Morphin algorithm. This system has the merits of optimal free-collision path, small memory size and less computing complexity, compared with the state of the arts in robot navigation. The modular design of 6-steps navigation provides a holistic methodology to implement and verify the performance of a robot’s navigation system. The experiments on simulation and a physical robot for the eight scenarios demonstrate that the robot can effectively and efficiently avoid potential collisions with any static or dynamic obstacles in its surrounding environment. Compared with the particle swarm optimisation, the dynamic window approach and the traditional Morphin algorithm for the autonomous navigation of a mobile robot in a static environment, ATCM achieved the shortest path with higher efficiency.


Author(s):  
Lee Gim Hee ◽  
◽  
Marcelo H. Ang Jr. ◽  

Global path planning algorithms are good in planning an optimal path in a known environment, but would fail in an unknown environment and when reacting to dynamic and unforeseen obstacles. Conversely, local navigation algorithms perform well in reacting to dynamic and unforeseen obstacles but are susceptible to local minima failures. A hybrid integration of both the global path planning and local navigation algorithms would allow a mobile robot to find an optimal path and react to any dynamic and unforeseen obstacles during an operation. However, the hybrid method requires the robot to possess full or partial prior information of the environment for path planning and would fail in a totally unknown environment. The integrated algorithm proposed and implemented in this paper incorporates an autonomous exploration technique into the hybrid method. The algorithm gives a mobile robot the ability to plan an optimal path and does online collision avoidance in a totally unknown environment.


2018 ◽  
Vol 27 (2) ◽  
pp. 93
Author(s):  
Iván A. Calle Flores ◽  
Rider V. Paredes Maraza ◽  
Cristopher Bazan Yaranga ◽  
Aldo A. Guardia Guizado

El presente proyecto consistió en la implementación de un robot móvil autónomo capaz de facilitar el flujo de documentos entre las diferentes áreas de una empresa, universidad, etc. Este robot es capaz de navegar de manera completamente autónoma en ambientes reales tal como los ambientes del CTIC, FIM, FIEE, etc. Tan solo especificando el punto inicial, el mapa del ambiente de navegación, y el punto deseado, este robot es capaz de generar el camino óptimo para llegar a dicha meta, y luego seguir este camino con la capacidad de evitar obstáculos si estos se presentan. Dadas estas características, este robot se puede usar en aplicaciones logísticas en donde el robot debe llevar paquetes, cargas, etc., a algún punto especificado por el usuario. En el proyecto se tienen dos modelos, el primer robot llamado R2D2‐R1 puede llevar cargas de hasta 3kg, y el segundo robot llamado R2D2‐R2 puede llevar cargas de hasta 25kg. Cabe señalar que los algoritmos implementados en este proyecto representan el estado del arte del campo de la robótica autónoma, y su desempeño se ha comprobado en las diversas pruebas de navegación realizadas en ambientes de la UNI. Este proyecto contribuye a cumplir con la misión de la UNI en los temas de innovación y gestión tecnológica para contribuir al bienestar de la sociedad y desarrollo del país. Palabras clave.- Robot móvil, navegación autónoma, planificación de trayectorias, evitamiento de obstáculos, aplicaciones logísticas. ABSTRACT The present project is about the implementation of an autonomous mobile robot designed for logistic tasks in different areas of a company, university, etc. This robot is able to navigate autonomously in real environments, you just need to specify the initial position, the grip map of the world and the target locations, and the robot will generate automatically the optimal path to reach the target positions, and then will follow this path while avoiding obstacles such as persons, trash bins, etc. These characteristics allow that our robot can be used in logistic tasks where the robot needs to carry loads from one place to another. In this project we developed two robot models, the first one called R2d2‐R1 can carry loads of up to 3kg, and the second one called can carry loads of up to 25Kg. The algorithms implemented in this project represent the state‐of‐the‐car methods and its performance has been proved in the several experiments carried out with these two robots. Keywords.- Mobile robot, autonomous navigation, path planning, obstacle avoidance, logistic applications.


Data Mining ◽  
2011 ◽  
pp. 1-21
Author(s):  
Vladimir Estivill-Castro ◽  
Michael Houle

Distance-based clustering results in optimization problems that typically are NP-hard or NP-complete and for which only approximate solutions are obtained. For the large instances emerging in data mining applications, the search for high-quality approximate solutions in the presence of noise and outliers is even more challenging. We exhibit fast and robust clustering methods that rely on the careful collection of proximity information for use by hill-climbing search strategies. The proximity information gathered approximates the nearest neighbor information produced using traditional, exact, but expensive methods. The proximity information is then used to produce fast approximations of robust objective optimization functions, and/or rapid comparison of two feasible solutions. These methods have been successfully applied for spatial and categorical data to surpass well-established methods such as k-MEANS in terms of the trade-off between quality and complexity.


2021 ◽  
Vol 26 (6) ◽  
pp. 1-22
Author(s):  
Chen Jiang ◽  
Bo Yuan ◽  
Tsung-Yi Ho ◽  
Xin Yao

Digital microfluidic biochips (DMFBs) have been a revolutionary platform for automating and miniaturizing laboratory procedures with the advantages of flexibility and reconfigurability. The placement problem is one of the most challenging issues in the design automation of DMFBs. It contains three interacting NP-hard sub-problems: resource binding, operation scheduling, and module placement. Besides, during the optimization of placement, complex constraints must be satisfied to guarantee feasible solutions, such as precedence constraints, storage constraints, and resource constraints. In this article, a new placement method for DMFB is proposed based on an evolutionary algorithm with novel heuristic-based decoding strategies for both operation scheduling and module placement. Specifically, instead of using the previous list scheduler and path scheduler for decoding operation scheduling chromosomes, we introduce a new heuristic scheduling algorithm (called order scheduler) with fewer limitations on the search space for operation scheduling solutions. Besides, a new 3D placer that combines both scheduling and placement is proposed where the usage of the microfluidic array over time in the chip is recorded flexibly, which is able to represent more feasible solutions for module placement. Compared with the state-of-the-art placement methods (T-tree and 3D-DDM), the experimental results demonstrate the superiority of the proposed method based on several real-world bioassay benchmarks. The proposed method can find the optimal results with the minimum assay completion time for all test cases.


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