scholarly journals A fast calibration approach for onboard LiDAR-camera systems

2020 ◽  
Vol 17 (2) ◽  
pp. 172988142090960
Author(s):  
Shang Erke ◽  
Dai Bin ◽  
Nie Yiming ◽  
Xiao Liang ◽  
Zhu Qi
Keyword(s):  
Autonomous Navigation ◽  
Camera System ◽  
Camera Systems ◽  
Field Environment ◽  
Novel Approach ◽  
Wide Range ◽  
Independent Calibration ◽  
The Relationship ◽  
Calibration Approach ◽  
Robot Platform

Outdoor surveillance and security robots have a wide range of industrial, military, and civilian applications. In order to achieve autonomous navigation, the LiDAR-camera system is widely applied by outdoor surveillance and security robots. The calibration of the LiDAR-camera system is essential and important for robots to correctly acquire the scene information. This article proposes a fast calibration approach that is different from traditional calibration algorithms. The proposed approach combines two independent calibration processes, which are the calibration of LiDAR and the camera to robot platform, so as to address the relationship between LiDAR sensor and camera sensor. A novel approach to calibrate LiDAR to robot platform is applied to improve accuracy and robustness. A series of indoor experiments are carried out and the results show that the proposed approach is effective and efficient. At last, it is applied to our own outdoor security robot platform to detect both positive and negative obstacles in a field environment, in which two Velodyne-HDL-32 LiDARs and a color camera are employed. The real application illustrates the robustness performance of the proposed approach.

An Experimental Analysis of the Effects of Different Hardware Setups on Stereo Camera Systems

2021 ◽  
Vol 15 (03) ◽  
pp. 337-357
Author(s):  
Alexander Julian Golkowski ◽  
Marcus Handte ◽  
Peter Roch ◽  
Pedro J. Marrón
Keyword(s):  
Experimental Analysis ◽  
Autonomous Navigation ◽  
Indoor Environments ◽  
Camera System ◽  
Stereo Camera ◽  
Camera Systems ◽  
Sensing Technology ◽  
Stereo Cameras ◽  
The Impact ◽  
General Guidance

For many application areas such as autonomous navigation, the ability to accurately perceive the environment is essential. For this purpose, a wide variety of well-researched sensor systems are available that can be used to detect obstacles or navigation targets. Stereo cameras have emerged as a very versatile sensing technology in this regard due to their low hardware cost and high fidelity. Consequently, much work has been done to integrate them into mobile robots. However, the existing literature focuses on presenting the concepts and algorithms used to implement the desired robot functions on top of a given camera setup. As a result, the rationale and impact of choosing this camera setup are usually neither discussed nor described. Thus, when designing the stereo camera system for a mobile robot, there is not much general guidance beyond isolated setups that worked for a specific robot. To close the gap, this paper studies the impact of the physical setup of a stereo camera system in indoor environments. To do this, we present the results of an experimental analysis in which we use a given software setup to estimate the distance to an object while systematically changing the camera setup. Thereby, we vary the three main parameters of the physical camera setup, namely the angle and distance between the cameras as well as the field of view and a rather soft parameter, the resolution. Based on the results, we derive several guidelines on how to choose the parameters for an application.

An Application of Fuzzy Logic to Service Quality Research: A Case of Fitness Service

2010 ◽  
Vol 24 (5) ◽  
pp. 502-523 ◽  
Author(s):  
Jose A. Martínez ◽  
Yong Jae Ko ◽  
Laura Martínez
Keyword(s):  
Fuzzy Logic ◽  
Sport Management ◽  
Fitness Centers ◽  
Novel Approach ◽  
Wide Range ◽  
Two Samples ◽  
Third Person ◽  
Fuzzy Techniques ◽  
The Relationship ◽  
The Third Person

This research focused on measuring perceived quality in the context of sport and fitness services using a novel approach in sport management: fuzzy logic. Several analytical procedures have been depicted to operate with fuzzy techniques, which may be applied to empirical research by a wide range of researchers in the sport literature, as well as sport managers. This study showed that fuzzy logic is an attractive method to increase the value of the information collected from customers’ evaluations. The implemented procedure overcomes the disadvantages of the research focused on the third-person approach, and minimizes the categorization bias and interaction bias derived from the relationship between verbal and numerical labels. An empirical study of two samples of consumers from two fitness centers illustrates the advantages of this method.

SECOND GENERATION OIL SPILL AND MARITIME SURVEILLANCE SYSTEMS NOW OPERATIONAL IN SWEDEN

1983 ◽  
Vol 1983 (1) ◽  
pp. 349-353 ◽  
Author(s):  
Lars Backlund ◽  
Lars Holmström
Keyword(s):  
Oil Spill ◽  
High Performance ◽  
Second Generation ◽  
Microwave Radiometer ◽  
Coast Guard ◽  
Surveillance Systems ◽  
Camera System ◽  
Maritime Surveillance ◽  
Camera Systems ◽  
Wide Range

ABSTRACT A new multisensor, integrated oil spill and maritime surveillance system now is in operational use by the Swedish Coast Guard. The system, developed by the Swedish Space Corporation, is based on experience with prototype side-looking airborne radar (SLAR), infrared/ultraviolet (IR/UV), and camera systems which were tested and operated between 1978 and 1981. The new system comprises second-generation, integrated SLAR, IR/UV, and camera systems together with supporting equipment for quick-look documentation and data recording. Sensor imagery is presented in real time on a television display. The system has been designed and optimized exclusively for maritime surveillance. The result is high performance at a very competitive price. Low weight and power consumption permit installation in a wide range of aircraft. System components such as an imagery link, a microwave radiometer and a TV-camera system are under development and will be added in the near future.

Determinants of species abundance in the Quaternary vertebrate fossil record

Paleobiology ◽  
2011 ◽  
Vol 37 (3) ◽  
pp. 537-546 ◽  
Author(s):  
Samuel T. Turvey ◽  
Tim M. Blackburn
Keyword(s):  
Body Mass ◽  
Species Abundance ◽  
Ecological Factors ◽  
General Applicability ◽  
Data Set ◽  
Terrestrial Vertebrate ◽  
Wide Range ◽  
Holocene Record ◽  
Independent Calibration ◽  
The Relationship

Species abundance data are of vital importance in paleontology, but fossil accumulations invariably represent a biased subset of original source communities. Efforts to quantify taphonomic biases are typically prevented by a lack of independent data on the ecological composition of prehistoric faunas. However, analysis of the continental Holocene record can provide a rare opportunity for independent calibration of fossil abundance patterns. We analyzed a comprehensive data set available for the Holocene avifauna of Sweden to investigate the relationship between species abundance in the recent fossil and zooarchaeological records and in prehistoric source communities, and to characterize the importance of different ecological factors in determining terrestrial vertebrate fossil abundances. The number of assemblages in which species occurred was compared with modern-day species abundance, annual residence, body mass, and ecological realm. Modern-day abundance is only one of several significant predictors of fossil abundance; the strongest predictor is body mass, and Holocene species abundance can be interpreted as a measure of species abundance in source communities for a given size class only. Our study represents one of the only direct attempts to quantify species abundance biases between fossil faunas and source communities, and has general applicability for a wide range of terrestrial vertebrate faunas.

scholarly journals UCalMiCeL – UNIFIED INTRINSIC AND EXTRINSIC CALIBRATION OF A MULTI-CAMERA-SYSTEM AND A LASERSCANNER

2017 ◽  
Vol IV-2/W3 ◽  
pp. 17-24 ◽  
Author(s):  
M. Hillemann ◽  
B. Jutzi
Keyword(s):  
Large Scale ◽  
Calibration Method ◽  
Bundle Adjustment ◽  
Sensor System ◽  
Small Scale ◽  
Camera System ◽  
Extrinsic Calibration ◽  
Camera Systems ◽  
The Individual ◽  
Calibration Approach

Unmanned Aerial Vehicle (UAV) with adequate sensors enable new applications in the scope between expensive, large-scale, aircraftcarried remote sensing and time-consuming, small-scale, terrestrial surveyings. To perform these applications, cameras and laserscanners are a good sensor combination, due to their complementary properties. To exploit this sensor combination the intrinsics and relative poses of the individual cameras and the relative poses of the cameras and the laserscanners have to be known. In this manuscript, we present a calibration methodology for the <i>Unified Intrinsic and Extrinsic Calibration of a Multi-Camera-System and a Laserscanner (UCalMiCeL)</i>. The innovation of this methodology, which is an extension to the calibration of a single camera to a line laserscanner, is an unifying bundle adjustment step to ensure an optimal calibration of the entire sensor system. We use generic camera models, including pinhole, omnidirectional and fisheye cameras. For our approach, the laserscanner and each camera have to share a joint field of view, whereas the fields of view of the individual cameras may be disjoint. The calibration approach is tested with a sensor system consisting of two fisheye cameras and a line laserscanner with a range measuring accuracy of 30&amp;thinsp;<i>mm</i>. We evaluate the estimated relative poses between the cameras quantitatively by using an additional calibration approach for Multi-Camera-Systems based on control points which are accurately measured by a motion capture system. In the experiments, our novel calibration method achieves a relative pose estimation with a deviation below 1.8&amp;deg; and 6.4&amp;thinsp;<i>mm</i>.

scholarly journals MOUNTING CALIBRATION OF A MULTI-VIEW CAMERA SYSTEM ON A UAV PLATFORM

2021 ◽  
Vol V-1-2021 ◽  
pp. 97-104
Author(s):  
M. Mohammadi ◽  
A. Khami ◽  
F. Rottensteiner ◽  
I. Neumann ◽  
C. Heipke
Keyword(s):  
Autonomous Navigation ◽  
Bundle Adjustment ◽  
Control Points ◽  
Camera System ◽  
Camera Systems ◽  
Ground Control Points ◽  
Laser Scanners ◽  
Engineering Geodesy ◽  
Close Range ◽  
Very High

Abstract. Multi-view camera systems are used more and more frequently for applications in close-range photogrammetry, engineering geodesy and autonomous navigation, since they can cover a large portion of the environment and are considerably cheaper than alternative sensors such as laser scanners. In many cases, the cameras do not have overlapping fields of view. In this paper, we report on the development of such a system mounted on a rigid aluminium platform, and focus on its geometric system calibration. We present an approach for estimating the exterior orientation of such a multi-camera system based on bundle adjustment. We use a static environment with ground control points, which are related to the platform via a laser tracker. In the experimental part, the precision and partly accuracy that can be achieved in different scenarios is investigated. While we show that the accuracy potential of the platform is very high, the mounting calibration parameters are not necessarily precise enough to be used as constant values after calibration. However, this disadvantage can be mitigated by using those parameters as observations and refining them on-the-job.

The Problem of Identifying and Modeling the Relationship between Monetary Factor and Inflation in the Russian Economy

2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko
Keyword(s):  
Money Supply ◽  
Money Demand ◽  
Russian Economy ◽  
Long Run ◽  
Complex Approach ◽  
Wide Range ◽  
Long Time ◽  
The Relationship ◽  
Supply Side Factors

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.

scholarly journals Responsive and Personalized Web Layouts with Integer Programming

2021 ◽  
Vol 5 (EICS) ◽  
pp. 1-23
Author(s):  
Markku Laine ◽  
Yu Zhang ◽  
Simo Santala ◽  
Jussi P. P. Jokinen ◽  
Antti Oulasvirta
Keyword(s):  
Integer Programming ◽  
Web Design ◽  
Web Pages ◽  
Web Page Design ◽  
Automated Generation ◽  
Novel Approach ◽  
Wide Range ◽  
Responsive Design ◽  
Responsive Web Design ◽  
Page Design

Over the past decade, responsive web design (RWD) has become the de facto standard for adapting web pages to a wide range of devices used for browsing. While RWD has improved the usability of web pages, it is not without drawbacks and limitations: designers and developers must manually design the web layouts for multiple screen sizes and implement associated adaptation rules, and its "one responsive design fits all" approach lacks support for personalization. This paper presents a novel approach for automated generation of responsive and personalized web layouts. Given an existing web page design and preferences related to design objectives, our integer programming -based optimizer generates a consistent set of web designs. Where relevant data is available, these can be further automatically personalized for the user and browsing device. The paper includes presentation of techniques for runtime adaptation of the designs generated into a fully responsive grid layout for web browsing. Results from our ratings-based online studies with end users (N = 86) and designers (N = 64) show that the proposed approach can automatically create high-quality responsive web layouts for a variety of real-world websites.

scholarly journals VAGADRONE: Intelligent and Fully Automatic Drone Based on Raspberry Pi and Android

2021 ◽  
Vol 11 (7) ◽  
pp. 3153
Author(s):  
Saifeddine Benhadhria ◽  
Mohamed Mansouri ◽  
Ameni Benkhlifa ◽  
Imed Gharbi ◽  
Nadhem Jlili
Keyword(s):  
Remote Control ◽  
Autonomous Navigation ◽  
Object Identification ◽  
External Control ◽  
Raspberry Pi ◽  
Optimal Trajectories ◽  
Live Streaming ◽  
Wide Range ◽  
Fully Automatic ◽  
Direct Use

Multirotor drones are widely used currently in several areas of life. Their suitable size and the tasks that they can perform are their main advantages. However, to the best of our knowledge, they must be controlled via remote control to fly from one point to another, and they can only be used for a specific mission (tracking, searching, computing, and so on). In this paper, we intend to present an autonomous UAV based on Raspberry Pi and Android. Android offers a wide range of applications for direct use by the UAV depending on the context of the assigned mission. The applications cover a large number of areas such as object identification, facial recognition, and counting objects such as panels, people, and so on. In addition, the proposed UAV calculates optimal trajectories, provides autonomous navigation without external control, detects obstacles, and ensures live streaming during the mission. Experiments are carried out to test the above-mentioned criteria.

scholarly journals Polymorphic Iterable Sequential Effect Systems

2021 ◽  
Vol 43 (1) ◽  
pp. 1-79
Author(s):  
Colin S. Gordon
Keyword(s):  
Algebraic Structure ◽  
Position Effect ◽  
Type Systems ◽  
Sequential Effect ◽  
Prior Work ◽  
Sequential Effects ◽  
Wide Range ◽  
The Relationship ◽  
Categorical Semantics

Effect systems are lightweight extensions to type systems that can verify a wide range of important properties with modest developer burden. But our general understanding of effect systems is limited primarily to systems where the order of effects is irrelevant. Understanding such systems in terms of a semilattice of effects grounds understanding of the essential issues and provides guidance when designing new effect systems. By contrast, sequential effect systems—where the order of effects is important—lack an established algebraic structure on effects. We present an abstract polymorphic effect system parameterized by an effect quantale—an algebraic structure with well-defined properties that can model the effects of a range of existing sequential effect systems. We define effect quantales, derive useful properties, and show how they cleanly model a variety of known sequential effect systems. We show that for most effect quantales, there is an induced notion of iterating a sequential effect; that for systems we consider the derived iteration agrees with the manually designed iteration operators in prior work; and that this induced notion of iteration is as precise as possible when defined. We also position effect quantales with respect to work on categorical semantics for sequential effect systems, clarifying the distinctions between these systems and our own in the course of giving a thorough survey of these frameworks. Our derived iteration construct should generalize to these semantic structures, addressing limitations of that work. Finally, we consider the relationship between sequential effects and Kleene Algebras, where the latter may be used as instances of the former.

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