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In this work, quantum cascade laser (QCL) mid-infrared (MIR) reflectance spectroscopy is used to discriminate silicate and carbonate minerals in a standoff measurement setting. The tunable external cavity QCL source that was used allows measurements from 5.2 μm to 13.4 μm wavelength, where the fundamental vibrational bands of silicates and carbonates are observed. Spectra measured from a half-core sample were analyzed using multivariate analysis to extract and identify the end-member spectra from the mixtures. The end-member spectra were compared and validated using the ASTER database spectra and the spectra measured on reference samples with the same QCL MIR reflectance spectroscopy setup. Spectra of minerals commonly found in the mining industry were compared: quartz, microcline, albite, chlorite, muscovite, biotite, calcite and dolomite. MIR reflectance spectroscopy using compact QCL sources allow rapid spectral measurements at standoff distances and high spatial resolution. All these advantages show the potential of QCL MIR reflectance spectroscopy for in-the-field mining applications., Spie Future Sensing Technologies, 9-13 November 2020, Online Only, Series: Proceedings of SPIE

This study aims at the evaluation of a prototype of a computerized trainer for cryosurgery—the controlled destruction of cancer tumors by freezing. The hypothesis in this study is that computer-based cryosurgery training for an optimal cryoprobe layout is essentially a matter of exposure time, rather than trainee background or the specific computer-generated planning target. Key geometric features under considerations are associated with spatial limitations on cryoprobes placement and the match between the resulted thermal field and the unique anatomy of the prostate. All experiments in this study were performed on the cryosurgery trainer—a prototype platform for computerized cryosurgery training, which has been presented previously. Among its key features, the cryosurgery trainer displays the prostate shape and its contours and provides a distance measurement tool on demand, in order to address spatial constraints during ultrasound imaging guidance. Another unique feature of the cryosurgery trainer is an output movie, displaying the simulated thermal field at the end of the cryoprocedure. The current study was performed on graduate engineering students having no formal background in medicine, and the results were benchmarked against data obtained on surgical residents having no experience with cryosurgery. Despite fundamental differences in background and experience, neither group displayed superior performance when it comes to cryoprobe layout planning. This study demonstrates that computer-based training of an optimal cryoprobe layout is feasible. This study demonstrates that the training quality is essentially related to the training exposure time, rather than to a specific planning strategy from those investigated.

For working parents, there's an intensity to Thursdays that can border on the overwhelming. Status reports are due, kids have tests to prepare for, and meetings pile up from projects unfinished from the week, making my Outlook calendar look like one of Piet Mondrian's more colorful works. Careful observers of my calendar are apt to notice, in the weeks between September and December, blocks of time appearing with an peculiar subject: LEGO coaching.

This paper presents a 3D distance measurement accuracy improvement for stereo vision systems using optimization methods A Stereo Vision system is developed and tested to identify common uncertainty sources. As the optimization methods are used to train a neural network, the resulting equation can be implemented in real time stereo vision systems. Computational experiments and a comparative analysis are conducted to identify a training function with a minimal error performance for such method. The offered method provides a general purpose modelling technique, attending diverse problems that affect stereo vision systems. Finally, the proposed method is applied in the developed stereo vision system and a statistical analysis is performed to validate the obtained improvements.

Analytical review of known methods of using the ultrasonic radars to detect and round the obstacles is proposed. There are researches of precision distance measurement to the object. It is shown that for distances uncertainty 4-150 cm the distance value is less than 2%. The method of authentication such obstacles, which compares the calculated value and the value is obtained experimentally by using radar. It uses the distance measurement to the object for 3 angles of ultrasonic module rotation. The specified maximum angle of ultrasonic radar platform rotation with fixed signal is reflected from the obstacle. The level of the reflected signal depends on the angle of reflection signal from obstacles, receiver sensitivity, reflectance signal and other parameters. The algorithms based on the data for the platform movement changing and performing round the obstacles are proposed. In the algorithms all possible options for receiving the reflected signal from obstacles are comprised., Выполнены исследования точности измерения расстояния до объекта. Показано, что для расстояний 4-150 см неопределенность значения расстояния не превышает 2 %. Предложено метод идентификации типа помехи, в котором сравниваются рассчитанное значение и значение, полученное экспериментально с помощью радара. При этом используются измерения расстояния до объекта для 3-х углов поворота ультразвукового модуля. Определен максимально допустимый угол поворота ультразвукового радара платформы, при котором фиксируется сигнал, отраженный от препятствия. На уровень отраженного сигнала влияют угол отражения сигнала от препятствия, чувствительность приемника, коэффициент отражения сигнала и другие параметры. На основе полученных данных предложены алгоритмы для изменения движения платформы с целью огибания препятствия., Виконані дослідження точності вимірювання реальної відстані до об’єкту та для 3-х кутів повороту ультразвукового модуля. На основі отриманих даних запропонований алгоритм для зміни руху платформи з метою огинання перешкоди.

In the past few years, research groups have focused on finding new solutions for objects detection in unknown and/or hazardous areas that can’t be accessed by humans, in order to create monitoring system that can ensure the safety and security of machine and humans operating in such areas. The aim of this study is to design and implement an object detection system based on XBee and ultrasonic sensor which is capable of detecting objects whether they are stationary or moving and obtain their exact location, direction and distance. This system is capable of detecting objects whether they are stationary or moving and obtain their exact location, direction and distance. It constantly monitors an area of limited range and reports to authorities, as soon as an object is detected two sets of alert can be activated at the same time. The first notification is an audible alert using a buzzer while the second one is a visual alert using personal computer screen with the help of graphical user interface. In addition to that, this system boasts many features such as low cost, tiny size, possible to carry and relocate with high efficiency and quality. Also it has a key advantage that is, this system doesn't require to be placed near the control room because it is able to monitor remote places and send the results wirelessly.

This paper presents two simple and cost effective indoor localisation methods. The first method uses ceiling-mounted wide-view angle webcam, computer vision and coloured circular markers, placed on the top of a robot. Main drawbacks of this method are lens distortion and sensitivity to lighting conditions. After solving these problems, a high localisation accuracy of ?1cm is achieved at about 5 Hz sampling rate. The second method is a version of trilateration, based on ultrasound time of flight distance measurement. An ultrasonic beacon is placed on a robot while wall detectors are strategically placed to avoid an excessive occlusion. The ZigBee network is used for inter-device synchronisation and for broadcasting measured data. Robot location is determined as a solution to the minimisation of measurement errors. Using Nelder-Mead algorithm and low-cost distance measuring devices, a solid sub 5 cm localisation accuracy is achieved at 10Hz.

Geolocation based on time differences of arrival measured by three sensors is studied. Closed-form analytical solutions are derived, even for the cases where one or more sensors are not located on the earth. Exploiting four sensors, full three-dimensional localisation is achieved as well. These numbers of sensors are minimal. The analytical results have been

The paper introduces testing procedures of several different geodetic centring devices performed mostly at the laboratory of the Research Institute of Geodesy, Topography and Cartography. Functional construction characteristics of a spherically mounted retroreflector Leica RRR 1.5’’, rotatable carriers Sokkia AP41 and Leica GZR3 and 12 different geodetic tribraches were examined. Further, a centring displacement instrument developed at the Czech Technical University in Prague, Faculty of Civil Engineering, Department of Special Geodesy, is evaluated in both laboratory and field conditions. For all tests, laser tracker Leica AT401 with a 5 μm standard uncertainty of absolute distance measurement, was employed.

The influence of the environmental configuration on ac magnetic distance and position measurement systems, which are based on inductive coupling of tuned resonators, is experimentally analyzed. The main aspects that affect the accuracy of such systems are the conductivity of the terrain and the presence of metallic materials near the resonators. It is shown that such aspects are frequency dependent, and a tradeoff is to be considered between the maximum operating range and the error. Moreover, a strategy to detect if the measurement results are corrupted by the environmental configuration is presented. The analysis is then extended to a positioning scenario where the prototype of a magnetic positioning system (MPS) is deployed and a comparison with a commercial ultrawideband (UWB) system is performed. The results show that the MPS performance is comparable with the commercial UWB system, leading to a mean positioning error of the order of 0.6 m when using an extended Kalman filter-based positioning algorithm.

In indoor localization, it is crucial to guarantee a high level of accuracy for various location-based services. An ultrasonic technique is one of the best candidates to meet this need because it is capable of performing precise distance measurements as well as enabling nonintrusive localization that requires no receiver to be carried. Nevertheless, its applicability is severely limited by the fact that ultrasonic waves are likely to collide with one another if a multiple access scheme is not equipped, as is usually the case for low-cost ultrasonic sensors. Also, environmental changes such as addition/removal of obstacles or dislocation of sensors themselves may further degrade the localization performance. To remedy these problems, we take a genetic approach to avoid collisions of ultrasonic waves, thereby maximizing the localization accuracy. Specifically, we propose a self-configurable, device-free, and low-cost ultrasonic sensor grouping technique for indoor localization that precisely quantifies the degree of collisions by using kernel distance and forms an optimal number of sensing groups to maximize the spatial reuse as well as to detect environmental changes in real time. Our comprehensive evaluation results on a real testbed demonstrate that it achieves very small localization errors of 20.6–32.6 cm, which is comparable with the size of target, i.e., human body, and detects any environmental change in 5.2–7 s followed by reconfiguring the sensing groups in 10.1–18.4 s.

Impulse radio ultrawideband ranging has recently received significant attention due to the high accuracy it can achieve. Although most research efforts have focused on ranging in indoor and outdoor environments, other environments such as harsh industrial environments introduce unique challenges. This paper discusses the impact of propagation characteristics of harsh industrial environments on ranging accuracy, and also discusses principles and challenges of non-line-of-sight identification in industrial scenarios. To illustrate these challenges, a measurement campaign using 802.15.4a radios was conducted in a Heavy Machines Laboratory. The results show that the non-line-of-sight condition can be accurately identified if adequate models for such an environment are used.

Traditional approaches to the construction site layout problem have been focused mainly on rectilinear and simple interpolated static geometrical shapes for modeling site facilities. Moreover, they have used proximity measures based on Cartesian distances between the centroids of the facilities. This is a fair abstraction of the problem; however it ignores the fact that many facilities on the construction sites assume non-rectilinear shapes that allow for better compaction within congested sites. The main focus of this research is to develop a new approach of modeling site facilities to overcome limitations and inefficiencies of previous models and to ensure a more realistic approach to construction site layout problems. A site layout optimization model was developed through a series of new algorithms for modeling regular and irregular freeform shapes of site facilities. The model mimics the “dynamic” behavior of the geometries of site facilities; where the geometrical shapes automatically modify their forms to fit in congested areas. Moreover, new proximity measures and distance measurement techniques were introduced. Furthermore, the research introduced the concept of selective zoning that significantly enhances optimization efficiency by minimizing the number of solutions through selection of pre-determined movement zones on site. At the end, a real site layout planning problem was solved using the developed model and the results were compared to two past models from the literature. The model has shown to be superior to the past models in optimizing congested and geometrically-complex site layouts.

This paper describes laboratory tests on a Leica AT401laser tracker. As the newer Leica AT402 model also uses the same firmware package, most of the results should also be valid for this device. First, we present the instrument’s firmware errors and the software used for testing. The ASME B89.4.19-2006 standard for testing laser trackers is briefly presented. The warm-up effect of the instrument is inspected with respect to both angle measurement and distance measurement. The absolute distance meter (ADM) is compared with a laboratory interferometer on a 30-meter long rail and also on a bench with automated movement of the carriage of the reflector. A time series of measurements for determining the additive constant is evaluated. A simple test of the stability of the distance measurement in field conditions is introduced. Most of the tests were carried out at the Research Institute of Geodesy, Topography and Cartography (RIGTC) and at the Faculty of Civil Engineering (FCE) of the Czech Technical University in Prague (CTU).

【In this paper, performance on receivers of multilateration (MLAT) system that uses ADS-B signal, which is recently becoming popular, was analyzed to overcome shortcomings of existing aircraft flight control systems or reinforce the capabilities. A link budget was analyzed using a channel model in the airport environment with regard to Local Area Multilateration (LAM) for ground-controlled landing around the airport. In order to detect signals that arrived at the receiver successfully, sensitivity of receiver was analyzed using a signal-to-noise ratio (SNR) worksheet, and a method that improves accuracy of the distance measurement was proposed by adopting a peak estimation using sampling signals. Through simulations, optimum specifications of receivers were analyzed to have high precision positioning of LAM, and accuracy of LAM distance measurements was presented.】

In this study, an WiFi fingerprinting method based on the k-nn algorithm was applied to improve the accuracy of location tracking of a moving train on a platform and evaluate the performance to minimize the estimation error of location tracking. The data related to the position of the moving train are monitored by the control center for trains and used widely for the safety and comfort of passengers. The train location tracking methods based on WiFi installed by telecom companies were evaluated. In this study, a simulator was developed to consider the environments of two cases; in already installed WiFi devices and new installed WiFi devices. The developed simulator can simulate the localized estimation of the position under a variety of conditions, such as the number of WiFi devices, the area of platform and entry velocity of train. To apply location tracking algorithms, a k-nn algorithm and fuzzy k-nn algorithm were applied selectively according to the underlying condition and also four distance measurement algorithms were applied to compare the error of location tracking. In conclusion, the best method to estimate train location tracking is a combination of the k-nn algorithm and Minkoski distance measurement at a 0.5m grid unit and 8 WiFi AP installed.

Purpose: This study examines distance from nurse station to bed according to composition of single bedroom. Methods: This study has two groups of target sample ward planes. The first group has diverse patients bedroom. The other group is 36 single bedrooms and 2 3-bedrooms. The guideline of distance measurement was instituted for consistency. This study has 3 main concepts of the guideline. 1) The distance is shortcut from NS to bed. 2) The traffic line is center line between walls and center of door. 3) The start point is center of NS and the end point is bed. Results: The result of this study can be summarized into two points. The first one is that single bedroom has good privacy and longer distance from NS to bed. The second one is that weak point of single bedroom was asked ward operating system and architectural planning like as patients room, bed per unit, location of NS and plan type. Implications: Consideration Should be taken into account for the effective bedroom composition and allocation in ward. This Stuy hopefully serve as a stepping stone for the standard design of space program in ward planning.

The man kind has been suffering with many diseases and abnormalities. Blindness is one of the disabilities which is very common and difficult to treat. The main motive of this paper is to help the blind people with a good and easy to use blind walking stick that uses a microcontroller to detect obstacles in front of him with many additional features which are quite cost effective. The stick will be meant for the rehabilitation of the blind people. The product is based on the distance measurement property of the ultrasonic sensors. It will measure the distance and velocity of the obstacle in the way of the person and will alarm the person about any obstacle (moving/stationary). The stick will allow detection of obstacles on the ground, holes and pits, uneven surfaces, steps, and other typical obstacles in the path of the person. Since the device is incorporated with wireless module it will be very handy and will be much easier to use as compared to the similar products available in the market. The white cane or stick is mostly preferred by the blind people for walking. But the limitation to the white cane is that the information obtained by the blind user is only by touching the objects by the tip of the cane, which is not completely reliable. Through this proposed paper we offer to give a solution which overcomes the limitations of the ordinary white cane. The ultrasonic blind walking stick is fully automated, comfortable to use and cheap. In other words, it is quite economic over the conventional method.

A contactless measuring method was developed to measure static positions of overhead contact lines from vehicles, using stereo image measurement and laser distance measurement. Measurement experiments were conducted. By using the combination of two types of sensors, this method can make high detection performance and high measurement accuracy compatible. Moreover, since it is completely contactless, measurement of wires not in contact with the pantograph, such as the catenary wire and the auxiliary catenary wire, is also possible. This method automates the measurement and quantification of condition diagnosis of long contact lines, and should increase maintenance efficiency.

Ultrasonic range measurement has the potential to obtain higher accuracy results while using continuous-wave signals due to its favorable capability of noise resistance. But in short distance ranging applications especially in the space-limited fields, there usually exists strong multiple echoes which will decline the distance measurement accuracy seriously. This paper presents a method to solve this problem through utilizing MLS-modulated continuous-wave signals. Meanwhile, this paper applies a combination of the cross-correlation method and phase shift technique for the high-resolution ultrasonic distance measurement. The synergy above would lead to very popular results. For example, the uncertainty in the measured distance is less than 40 μm for distances up to 200 mm in distilled water.

Nowadays, a large number of novel technologies and systems are invented in order to solve the problems of Indoor Positioning Systems (IPS). One of the most well- known and common positioning technology is ultrasound. The zero rooms’ leakage, low cost, scalability, reliability, and less complexity in hardware and computing are the main advantages of ultrasonic systems. However, existing ultrasonic systems are hampered by many problems such as uncertainty and reduced robustness. This paper contributes an approach with the intention of improving distance measurement for indoor robot positioning by using an ultrasonic sensor. In the proposed method, start point of received signal will be determined more precisely.

Nowadays, indoor localization systems gain more and more attention, as demand for the services employing data on the indoor position of the objects and people is growing. There are many techniques used for position calculation. The most popular rely on measurements of radio wave propagation times. Most of the systems' architectures consist of localized tags and fixed-positioned anchor nodes. Knowledge on the precise localization of the nodes is often crucial for correct calculation of the tags' positions. Therefore, for robust system's exploitation a method for evaluating and correcting shifted anchor's position is necessary. Such method is presented in the paper, along with the explanation of the proposed algorithm and experimental results.

Nowadays, as indoor localization systems are gaining their popularity, simple installation and deployment become more important. The paper deals with the problem of anchor nodes position estimation. In most cases, to be able to calculate the tag's positions it is necessary to know the exact positions of the elements of the system's infrastructure. The method for anchor nodes' position estimation based on the distances between them and the tag is presented. The paper contains description of the method and results of the performed simulations.