PERFORMANCE ANALYSIS OF HECTOR SLAM AND GMAPPING FOR NAVIGATION FOR MOBILE ROBOT NAVIGATION

One of the most significant elements of a moving robot is mapping. The robot's capacity to identify its surroundings and translate them into a map allows it to navigate effectively from one spot to another while avoiding impediments that may arise during the navigation process. The SLAM method already has a mapping capability, so it can continuously localize the position against the map. In this experiment, 2D laser scanning data was obtained using RPlidar-A1 and then processed by the slam algorithm, namely gmapping and hector mapping to produce an occupancy grid map. The map is displayed by the RViz visualization widget, and its length is measured using the RViz measurement tools. The results of the occupancy grid map generated by the gmapping algorithm with a laser scan matcher have a lot of noise, and lose orientation. At the measured point length, the gmapping algorithm has slightly more error. The hector mapping algorithm has better performance than gmapping with a laser scan matcher on the RPLidar-A1 device

Evaluation of SLAM algorithms for Search and Rescue applications

This research investigates three SLAM algorithms on a low-cost mobile robot and finds the algorithms’ performance through a set of experiments including different types of ground surfaces

Design and Implementation of Indoor Disinfection Robot System

After the outbreak of COVID-19 virus, disinfection has become one of the important means of epidemic prevention. Traditional manual disinfection can easily cause cross infection problems. Using robots to complete disinfection work can reduce people's social contact and block the spread of viruses. This thesis implements an engineering prototype of a indoor disinfection robot from the perspective of product development, with the amin of using robots to replace manual disinfection operations. The thesis uses disinfection module, control module and navigation module to compose the hardware of the robot. The disinfection module uses ultrasonic atomizers, UV-C ultraviolet disinfection lamps, and air purifiers to disinfect and disinfect the ground and air respectively. The control module is responsible for the movement and obstacle avoidance of the robot. The navigation module uses Raspberry Pi and LiDAR to achieve real-time robot positioning and two-dimensional plane mapping. In terms of robot software,we have done the following work: (1) Based on the ROS framework, we have implemented functions such as SLAM mapping, location positioning, and odometer data calibration.(2) Customize communication protocols to manage peripheral devices such as UV-C lights, ultrasonic atomizers, air purifiers, and motors on the control board. (3) Develop an Android mobile app that utilizes ROSBridge's lightweight communication architecture to achieve cross platform data exchange between mobile devices and navigation boards, as well as network connectivity and interaction between mobile phones and robots Finally, this thesis implements an engineering prototype of a household disinfection robot from the perspective of product development

Autonomous Flight in Unknown Indoor Environments

http://multi-science.metapress.com/content/80586kml376k2711/This paper presents our solution for enabling a quadrotor helicopter, equipped with a laser rangefinder sensor, to autonomously explore and map unstructured and unknown indoor environments. While these capabilities are already commodities on ground vehicles, air vehicles seeking the same performance face unique challenges. In this paper, we describe the difficulties in achieving fully autonomous helicopter flight, highlighting the differences between ground and helicopter robots that make it difficult to use algorithms that have been developed for ground robots. We then provide an overview of our solution to the key problems, including a multilevel sensing and control hierarchy, a high-speed laser scan-matching algorithm, an EKF for data fusion, a high-level SLAM implementation, and an exploration planner. Finally, we show experimental results demonstrating the helicopter's ability to navigate accurately and autonomously in unknown environments.National Science Foundation (U.S.) (NSF Division of Information and Intelligent Systems under grant # 0546467)United States. Army Research Office (ARO MAST CTA)Singapore. Armed Force

Multi-layered map based navigation and interaction for an intelligent wheelchair

Intelligent wheelchair is a paradigm of assisted living applications for elderly and disabled people. Its autonomous navigation and human-robot interaction is the major challenge. The previous intelligent wheelchair research has been mainly focused on geometric map based navigation, which is computational expensive in a large scale environment. This paper proposes the use of multi-layered maps for navigation and interaction of an intelligent wheelchair. The semantic information can improve the efficiency of path planning and navigation as well as extend the capability of task planning for the wheelchair. Some experimental results are given to demonstrate the feasibility and performance of the proposed approach

SLAM research for port AGV based on 2D LIDAR

With the increase in international trade, the transshipment of goods at international container ports is very busy. The AGV (Automated Guided Vehicle) has been used as a new generation of automated container horizontal transport equipment. The AGV is an automated unmanned vehicle that can work 24 hours a day, increasing productivity and reducing labor costs compared to using container trucks. The ability to obtain information about the surrounding environment is a prerequisite for the AGV to automatically complete tasks in the port area. At present, the method of AGV based on RFID tag positioning and navigation has a problem of excessive cost. This dissertation has carried out a research on applying light detection and ranging (LIDAR) simultaneous localization and mapping (SLAM) technology to port AGV. In this master's thesis, a mobile test platform based on a laser range finder is developed to scan 360-degree environmental information (distance and angle) centered on the LIDAR and upload the information to a real-time database to generate surrounding environmental maps, and the obstacle avoidance strategy was developed based on the acquired information. The effectiveness of the platform was verified by the experiments from multiple scenarios. Then based on the first platform, another experimental platform with encoder and IMU sensor was developed. In this platform, the functionality of SLAM is enabled by the GMapping algorithm and the installation of the encoder and IMU sensor. Based on the established environment SLAM map, the path planning and obstacle avoidance functions of the platform were realized.Com o aumento do comércio internacional, o transbordo de mercadorias em portos internacionais de contentores é muito movimentado. O AGV (“Automated Guided Vehicle”) foi usado como uma nova geração de equipamentos para transporte horizontal de contentores de forma automatizada. O AGV é um veículo não tripulado automatizado que pode funcionar 24 horas por dia, aumentando a produtividade e reduzindo os custos de mão-de-obra em comparação com o uso de camiões porta-contentores. A capacidade de obter informações sobre o ambiente circundante é um pré-requisito para o AGV concluir automaticamente tarefas na área portuária. Atualmente, o método de AGV baseado no posicionamento e navegação de etiquetas RFID apresenta um problema de custo excessivo. Nesta dissertação foi realizada uma pesquisa sobre a aplicação da tecnologia LIDAR de localização e mapeamento simultâneo (SLAM) num AGV. Uma plataforma de teste móvel baseada num telémetro a laser é desenvolvida para examinar o ambiente em redor em 360 graus (distância e ângulo), centrado no LIDAR, e fazer upload da informação para uma base de dados em tempo real para gerar um mapa do ambiente em redor. Uma estratégia de prevenção de obstáculos foi também desenvolvida com base nas informações adquiridas. A eficácia da plataforma foi verificada através da realização de testes com vários cenários e obstáculos. Por fim, com base na primeira plataforma, uma outra plataforma experimental com codificador e sensor IMU foi também desenvolvida. Nesta plataforma, a funcionalidade do SLAM é ativada pelo algoritmo GMapping e pela instalação do codificador e do sensor IMU. Com base no estabelecimento do ambiente circundante SLAM, foram realizadas as funções de planeamento de trajetória e prevenção de obstáculos pela plataforma

Development of an adaptive navigation system for indoor mobile handling and manipulation platforms

A fundamental technology enabling the autonomous behavior of mobile robotics is navigation. It is a main prerequisite for mobile robotics to fulfill high-level tasks such as handling and manipulation, and is often identified as one of the key challenges in mobile robotics. The mapping and localization as the basis for navigation are intensively researched in the last few decades. However, there are still challenges or problems needed to be solved for online operating in large-scale environments or running on low-cost and energy-saving embedded systems. In this work, new developments and usages of Light Detection And Ranging (LiDAR) based Simultaneous Localization And Mapping (SLAM) algorithms are presented. A key component of LiDAR based SLAM algorithms, the scan matching algorithm, is explored. Different scan matching algorithms are systemically experimented with different LiDARs for indoor home-like environments for the first time. The influence of properties of LiDARs in scan matching algorithms is quantitatively analyzed. Improvements to Bayes filter based and graph optimization based SLAMs are presented. The Bayes filter based SLAMs mainly use the current sensor information to find the best estimation. A new efficient implementation of Rao-Blackwellized Particle Filter based SLAM is presented. It is based on a pre-computed lookup table and the parallelization of the particle updating. The new implementation runs efficiently on recent multi-core embedded systems that fulfill low cost and energy efficiency requirements. In contrast to Bayes filter based methods, graph optimization based SLAMs utilize all the sensor information and minimize the total error in the system. A new real-time graph building model and a robust integrated Graph SLAM solution are presented. The improvements include the definition of unique direction norms for points or lines extracted from scans, an efficient loop closure detection algorithm, and a parallel and adaptive implementation. The developed algorithm outperforms the state-of-the-art algorithms in processing time and robustness especially in large-scale environments using embedded systems instead of high-end computation devices. The results of the work can be used to improve the navigation system of indoor autonomous robots, like domestic environments and intra-logistics.Eine der grundlegenden Funktionen, welche die Autonomie in der mobilen Robotik ermöglicht, ist die Navigation. Sie ist eine wesentliche Voraussetzung dafür, dass mobile Roboter selbständig anspruchsvolle Aufgaben erfüllen können. Die Umsetzung der Navigation wird dabei oft als eine der wichtigsten Herausforderungen identifiziert. Die Kartenerstellung und Lokalisierung als Grundlage für die Navigation wurde in den letzten Jahrzehnten intensiv erforscht. Es existieren jedoch immer noch eine Reihe von Problemen, z.B. die Anwendung auf große Areale oder bei der Umsetzung auf kostengünstigen und energiesparenden Embedded-Systemen. Diese Arbeit stellt neue Ansätze und Lösungen im Bereich der LiDAR-basierten simultanen Positionsbestimmung und Kartenerstellung (SLAM) vor. Eine Schlüsselkomponente der LiDAR-basierten SLAM, die so genannten Scan-Matching-Algorithmen, wird näher untersucht. Verschiedene Scan-Matching-Algorithmen werden zum ersten Mal systematisch mit verschiedenen LiDARs für den Innenbereich getestet. Der Einfluss von LiDARs auf die Eigenschaften der Algorithmen wird quantitativ analysiert. Verbesserungen an Bayes-filterbasierten und graphoptimierten SLAMs werden in dieser Arbeit vorgestellt. Bayes-filterbasierte SLAMs verwenden hauptsächlich die aktuellen Sensorinformationen, um die beste Schätzung zu finden. Eine neue effiziente Implementierung des auf Partikel-Filter basierenden SLAM unter der Verwendung einer Lookup-Tabelle und der Parallelisierung wird vorgestellt. Die neue Implementierung kann effizient auf aktuellen Embedded-Systemen laufen. Im Gegensatz dazu verwenden Graph-SLAMs alle Sensorinformationen und minimieren den Gesamtfehler im System. Ein neues Echtzeitmodel für die Grafenerstellung und eine robuste integrierte SLAM-Lösung werden vorgestellt. Die Verbesserungen umfassen die Definition von eindeutigen Richtungsnormen für Scan, effiziente Algorithmen zur Erkennung von Loop Closures und eine parallele und adaptive Implementierung. Der entwickelte und auf eingebetteten Systemen eingesetzte Algorithmus übertrifft die aktuellen Algorithmen in Geschwindigkeit und Robustheit, insbesondere für große Areale. Die Ergebnisse der Arbeit können für die Verbesserung der Navigation von autonomen Robotern im Innenbereich, häuslichen Umfeld sowie der Intra-Logistik genutzt werden

From Perception to Navigation in Environments with Persons: An Indoor Evaluation of the State of the Art

Research in the field of social robotics is allowing service robots to operate in environments with people. In the aim of realizing the vision of humans and robots coexisting in the same environment, several solutions have been proposed to (1) perceive persons and objects in the immediate environment; (2) predict the movements of humans; as well as (3) plan the navigation in agreement with socially accepted rules. In this work, we discuss the different aspects related to social navigation in the context of our experience in an indoor environment. We describe state-of-the-art approaches and experiment with existing methods to analyze their performance in practice. From this study, we gather first-hand insights into the limitations of current solutions and identify possible research directions to address the open challenges. In particular, this paper focuses on topics related to perception at the hardware and application levels, including 2D and 3D sensors, geometric and mainly semantic mapping, the prediction of people trajectories (physics-, pattern- and planning-based), and social navigation (reactive and predictive) in indoor environments

An FPGA Acceleration and Optimization Techniques for 2D LiDAR SLAM Algorithm

An efficient hardware implementation for Simultaneous Localization and Mapping (SLAM) methods is of necessity for mobile autonomous robots with limited computational resources. In this paper, we propose a resource-efficient FPGA implementation for accelerating scan matching computations, which typically cause a major bottleneck in 2D LiDAR SLAM methods. Scan matching is a process of correcting a robot pose by aligning the latest LiDAR measurements with an occupancy grid map, which encodes the information about the surrounding environment. We exploit an inherent parallelism in the Rao-Blackwellized Particle Filter (RBPF) based algorithms to perform scan matching computations for multiple particles in parallel. In the proposed design, several techniques are employed to reduce the resource utilization and to achieve the maximum throughput. Experimental results using the benchmark datasets show that the scan matching is accelerated by 5.31-8.75x and the overall throughput is improved by 3.72-5.10x without seriously degrading the quality of the final outputs. Furthermore, our proposed IP core requires only 44% of the total resources available in the TUL Pynq-Z2 FPGA board, thus facilitating the realization of SLAM applications on indoor mobile robots