Verification of the indoor GPS system, by comparison with calibrated coordinates and by angular reference

This paper details work carried out to verify the dimensional measurement performance of the Indoor GPS (iGPS) system; a network of Rotary-Laser Automatic Theodolites (R-LATs). Initially tests were carried out to determine the angular uncertainties on an individual R-LAT transmitter-receiver pair. A method is presented of determining the uncertainty of dimensional measurement for a three dimensional coordinate measurement machine. An experimental procedure was developed to compare three dimensional coordinate measurements with calibrated reference points. The reference standard used to calibrate these reference points was a fringe counting interferometer with the multilateration technique employed to establish three dimensional coordinates. This is an extension of the established technique of comparing measured lengths with calibrated lengths. The method was found to be practical and able to establish that the expanded uncertainty of the basic iGPS system was approximately 1 mm at a 95% confidence level. Further tests carried out on a highly optimized version of the iGPS system have shown that the coordinate uncertainty can be reduced to 0.25 mm at a 95% confidence level

Estimation of uncertainty in three-dimensional coordinate measurement by comparison with calibrated points

This paper details a method of estimating the uncertainty of dimensional measurement for a three-dimensional coordinate measurement machine. An experimental procedure was developed to compare three-dimensional coordinate measurements with calibrated reference points. The reference standard used to calibrate these reference points was a fringe counting interferometer with a multilateration-like technique employed to establish three-dimensional coordinates. This is an extension of the established technique of comparing measured lengths with calibrated lengths. Specifically a distributed coordinate measurement device was tested which consisted of a network of Rotary-Laser Automatic Theodolites (R-LATs), this system is known commercially as indoor GPS (iGPS). The method was found to be practical and was used to estimate that the uncertainty of measurement for the basic iGPS system is approximately 1 mm at a 95% confidence level throughout a measurement volume of approximately 10 m × 10 m × 1.5 m. © 2010 IOP Publishing Ltd

Characterization of Quad-Copter Positioning Systems and the Effect of Pose Uncertainties on Field Probe Measurements

When measuring the Radar Cross Section (RCS) of a test object, many uncertainties must be accounted for, such as the non-homogeneous nature of the medium between the radar test equipment and the platform under test. There are a variety of other error sources, including clutter and Radio Frequency Interference (RFI), motivating the development of techniques to measure and model the uncertainties in RCS measurements. The following research, in unison with prior and current efforts, intends to reduce the impact of these uncertainties by utilizing a unique two-way field probe in the form of a geodesic sphere encompassing a commercial quad-copter aircraft. The probe is used to measure the incident fields in the target volume in an effort to quantify one of the key sources of uncertainty in an RCS measurement, distortions in the incident wave. In order to do this, the geodesic sphere must be fully understood. This research determined the uncertainty of the probe by creating a calibrated data set of the probe’s RCS, extracting the calibrated RCS based on the measurement flight path, comparing the measured with the calibrated data, and determining the deviation in the difference. The accuracy of the comparison, and therefore the measurement, depends on the accuracy of the flight path. An uncertainty in the probe’s position and orientation during flight translates into a field measurement uncertainty. These uncertainties were determined for the Parrot Bebop quad-copter, a differential GPS, and a Vicon™ system. Each uncertainty was fed into the measurement model and their measurement uncertainties were determined. Field measurement accuracies of \u3c 2° in phase and \u3c 0.05V/m in magnitude were demonstrated

Anchor Self-Calibrating Schemes for UWB based Indoor Localization

Traditional indoor localization techniques that use Received Signal Strength or Inertial Measurement Units for dead-reckoning suffer from signal attenuation and sensor drift, resulting in inaccurate position estimates. Newly available Ultra-Wideband radio modules can measure distances at a centimeter-level accuracy while mitigating the effects of multipath propagation due to their very fine time resolution. Known locations of fixed anchor nodes are required to determine the position of tag nodes within an indoor environment. For a large system consisting of several anchor nodes spanning a wide area, physically mapping out the locations of each anchor node is a tedious task and thus makes the scalability of such systems difficult. Hence it is important to develop indoor localization systems wherein the anchors can self-calibrate by determining their relative positions in Euclidean 3D space with respect to each other. In this thesis, we propose two novel anchor self-calibrating algorithms - Triangle Reconstruction Algorithm (TRA) and Channel Impulse Response Positioning (CIRPos) that improve upon existing range-based implementations and solve existing problems such as flip ambiguity and node localization success rate. The localization accuracy and scalability of the self-calibrating anchor schemes are tested in a simulated environment based on the ranging accuracy of the Ultra-Wideband modules

Large volume metrology technologies for the light controlled factory

In the Light Controlled Factory part-to-part assembly and reduced weight will be enabled through the use of predictive fitting processes; low cost high accuracy reconfigurable tooling will be made possible by active compensation; improved control will allow accurate robotic machining; and quality will be improved through the use of traceable uncertainty based quality control throughout the production system. A number of challenges must be overcome before this vision will be realized; 1) controlling industrial robots for accurate machining; 2) compensation of measurements for thermal expansion; 3) Compensation of measurements for refractive index changes; 4) development of Embedded Metrology Tooling for in-tooling measurement and active tooling compensation; and 5) development of Software for the Planning and Control of Integrated Metrology Networks based on Quality Control with Uncertainty Evaluation and control systems for predictive processes. This paper describes how these challenges are being addressed, in particular the central challenge of developing large volume measurement process models within an integrated dimensional variation management (IDVM) system

New Techniques for the Measurement of Second and Third Generation Photovoltaics

New generations of photovoltaics (PV) have demonstrated a significant cost-reduction with respect to c-Si wafer-based modules. Though second (thin-film) and third generation PV (high-intensity, low-cost) are already in the PV market, the preparation of standard procedures for their characterization is still ongoing. This work was developed by the author in order to extend some of the existing characterization techniques to a set of three different emerging technologies: multi-junction thin-film modules, concentrator PV cells and luminescent solar concentrators. An original method for the spectral response measurement of large area thin-film multijunction modules is presented in the first part: the method is validated with several examples. A basic theoretical approach is also presented to propose innovative explanations of measurement artefacts that are observed in the literature. In the second part of the thesis, the setup, characterization and classification of a high intensity pulsed solar simulator for concentrator PV cells is illustrated. A new procedure for the preparation of a set of filtered reference cells for the irradiance detection at high intensities is also presented, providing an original tool for the verification of the linearity of these devices towards irradiance, which is usually assumed in the literature. In the third part the performance characterization of high-efficiency luminescent solar concentrators is presented: a simple ray-tracing model and its experimental validation, the impact of backside diffusive reflector on the performance of this kind of devices are mainly highlighted. The work was developed in support of the activities of the European Solar Test Installation laboratory of the European Commission, a centre of reference for PV testing

RuDaCoP: The Dataset for Smartphone-based Intellectual Pedestrian Navigation

This paper presents the large and diverse dataset for development of smartphone-based pedestrian navigation algorithms. This dataset consists of about 1200 sets of inertial measurements from sensors of several smartphones. The measurements are collected while walking through different trajectories up to 10 minutes long. The data are accompanied by the high accuracy ground truth collected with two foot-mounted inertial measurement units and post-processed by the presented algorithms. The dataset suits both for training of intellectual pedestrian navigation algorithms based on learning techniques and for development of pedestrian navigation algorithms based on classical approaches. The dataset is accessible at http://gartseev.ru/projects/ipin2019

Cost-effective robot for steep slope crops monitoring

This project aims to develop a low cost, simple and robust robot able to autonomously monitorcrops using simple sensors. It will be required do develop robotic sub-systems and integrate them with pre-selected mechanical components, electrical interfaces and robot systems (localization, navigation and perception) using ROS, for wine making regions and maize fields

Drone heading calculation indoors

Abstract. Aim of this master’s thesis was to study drone flying indoors and propose a drone-implemented system that enables the drone heading calculation. In the outdoors, the heading is calculated effectively with a drone’s sensors but using them indoors is limited. Indoor positioning currently has not both low-cost and reliable solution for drone heading calculating. The differences between indoor flying principles and outdoor flying principles of the drone are described in the beginning of the thesis. Then different ways to determine the drone’s heading indoors and how they compare with one another are discussed. Finally, two different heading calculation methods are implemented and tested. The methods are based on using multiple location measurements on the drone and using machine vision together with machine learning. Both methods are affordable and are evaluated to see if they could enable drone flying indoors. First method gives out potential results based on testing results, but it needs further development to be able to always provide reliable heading. Second method shows poor results based on verification.Dronen lentosuunnan laskenta sisätiloissa. Tiivistelmä. Työn tavoitteena oli tutkia dronen lentämistä sisätiloissa ja ehdottaa sitä varten droneen implementoitavaa systeemiä, joka mahdollistaa dronen suunnan laskennan. Ulkona suuntatieto saadaan dronen sensorien avulla, mutta sisätiloissa niiden tarkkuus ei riitä samalla tavalla. Sisätilapaikannuksessa ei ole olemassa sekä edullista että luotettavaa ratkaisua dronen suunnan laskentaan. Työssä perehdytään aluksi dronen lentämisen periaatteisiin sisätiloissa ja miten ne eroavat ulkona lentämisestä. Sitten kerrotaan erilaisista keinoista määrittää dronen suunta sisätiloissa ja niiden keskinäisestä vertailusta. Lopuksi testataan kahta erilaista suunnan-laskenta-menetelmää, jotka perustuvat paikkatiedon käyttöön ja konenäköön yhdessä koneoppimisen kanssa. Menetelmät ovat edullisia ja niiden sopivuutta dronen sisälennätykseen arvioidaan. Ensimmäinen menetelmä antaa hyviä testituloksia mutta tarvitsee lisää jatkokehitystä, jotta se voisi antaa aina luotettavaa suuntatietoa. Toinen menetelmä antaa heikkoja tuloksia verifioinnin perusteella