LiDAR-IMU Time Delay Calibration Based on Iterative Closest Point and Iterated Sigma Point Kalman Filter.

Science.gov (United States)

Liu, Wanli

2017-03-08

The time delay calibration between Light Detection and Ranging (LiDAR) and Inertial Measurement Units (IMUs) is an essential prerequisite for its applications. However, the correspondences between LiDAR and IMU measurements are usually unknown, and thus cannot be computed directly for the time delay calibration. In order to solve the problem of LiDAR-IMU time delay calibration, this paper presents a fusion method based on iterative closest point (ICP) and iterated sigma point Kalman filter (ISPKF), which combines the advantages of ICP and ISPKF. The ICP algorithm can precisely determine the unknown transformation between LiDAR-IMU; and the ISPKF algorithm can optimally estimate the time delay calibration parameters. First of all, the coordinate transformation from the LiDAR frame to the IMU frame is realized. Second, the measurement model and time delay error model of LiDAR and IMU are established. Third, the methodology of the ICP and ISPKF procedure is presented for LiDAR-IMU time delay calibration. Experimental results are presented that validate the proposed method and demonstrate the time delay error can be accurately calibrated.

Loose fusion based on SLAM and IMU for indoor environment

Science.gov (United States)

Zhu, Haijiang; Wang, Zhicheng; Zhou, Jinglin; Wang, Xuejing

2018-04-01

The simultaneous localization and mapping (SLAM) method based on the RGB-D sensor is widely researched in recent years. However, the accuracy of the RGB-D SLAM relies heavily on correspondence feature points, and the position would be lost in case of scenes with sparse textures. Therefore, plenty of fusion methods using the RGB-D information and inertial measurement unit (IMU) data have investigated to improve the accuracy of SLAM system. However, these fusion methods usually do not take into account the size of matched feature points. The pose estimation calculated by RGB-D information may not be accurate while the number of correct matches is too few. Thus, considering the impact of matches in SLAM system and the problem of missing position in scenes with few textures, a loose fusion method combining RGB-D with IMU is proposed in this paper. In the proposed method, we design a loose fusion strategy based on the RGB-D camera information and IMU data, which is to utilize the IMU data for position estimation when the corresponding point matches are quite few. While there are a lot of matches, the RGB-D information is still used to estimate position. The final pose would be optimized by General Graph Optimization (g2o) framework to reduce error. The experimental results show that the proposed method is better than the RGB-D camera's method. And this method can continue working stably for indoor environment with sparse textures in the SLAM system.

A comparison of stable platform and strapdown airborne gravity

DEFF Research Database (Denmark)

Glennie, C.L.; Schwarz, K.P.; Bruton, A.M.

2000-01-01

To date, operational airborne gravity results have been obtained using either a damped two-axis stable platform gravimeter system such as the LaCoste and Romberg (LCR) S-model marine gravimeter or a strapdown inertial navigation system (INS), showing comparable accuracies. In June 1998 three flight...

a Man-Portable Imu-Free Mobile Mapping System

Science.gov (United States)

Nüchter, A.; Borrmann, D.; Koch, P.; Kühn, M.; May, S.

2015-08-01

Mobile mapping systems are commonly mounted on cars, ships and robots. The data is directly geo-referenced using GPS data and expensive IMU (inertial measurement systems). Driven by the need for flexible, indoor mapping systems we present an inexpensive mobile mapping solution that can be mounted on a backpack. It combines a horizontally mounted 2D profiler with a constantly spinning 3D laser scanner. The initial system featuring a low-cost MEMS IMU was revealed and demonstrated at MoLaS: Technology Workshop Mobile Laser Scanning at Fraunhofer IPM in Freiburg in November 2014. In this paper, we present an IMU-free solution.

Low-cost inertial measurement unit.

Energy Technology Data Exchange (ETDEWEB)

Deyle, Travis Jay

2005-03-01

Sandia National Laboratories performs many expensive tests using inertial measurement units (IMUs)--systems that use accelerometers, gyroscopes, and other sensors to measure flight dynamics in three dimensions. For the purpose of this report, the metrics used to evaluate an IMU are cost, size, performance, resolution, upgradeability and testing. The cost of a precision IMU is very high and can cost hundreds of thousands of dollars. Thus the goals and results of this project are as follows: (1) Examine the data flow in an IMU and determine a generic IMU design. (2) Discuss a high cost IMU implementation and its theoretically achievable results. (3) Discuss design modifications that would save money for suited applications. (4) Design and implement a low cost IMU and discuss its theoretically achievable results. (5) Test the low cost IMU and compare theoretical results with empirical results. (6) Construct a more streamlined printed circuit board design reducing noise, increasing capabilities, and constructing a self-contained unit. Using these results, we can compare a high cost IMU versus a low cost IMU using the metrics from above. Further, we can examine and suggest situations where a low cost IMU could be used instead of a high cost IMU for saving cost, size, or both.

Modern Breakthrough Technologies Enable New Applications Based on IMU Systems

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Nunzio Abbate

2011-01-01

Full Text Available This paper describes IMU (Inertial Measurement Unit platforms and their main target applications with a special focus on the 10-degree-of-freedom (10-DOF inertial platform iNEMO and its technical features and performances. The iNEMO module is equipped with a 3-axis MEMS accelerometer, a 3-axis MEMS gyroscope, a 3-axis MEMS magnetometer, a pressure sensor, and a temperature sensor. Furthermore, the Microcontroller Unit (MCU collects measurements by the sensors and computes the orientation through a customized Extended Kalman Filter (EKF for sensor fusion.

Real-Time Large Scale 3d Reconstruction by Fusing Kinect and Imu Data

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Huai, J.; Zhang, Y.; Yilmaz, A.

2015-08-01

Kinect-style RGB-D cameras have been used to build large scale dense 3D maps for indoor environments. These maps can serve many purposes such as robot navigation, and augmented reality. However, to generate dense 3D maps of large scale environments is still very challenging. In this paper, we present a mapping system for 3D reconstruction that fuses measurements from a Kinect and an inertial measurement unit (IMU) to estimate motion. Our major achievements include: (i) Large scale consistent 3D reconstruction is realized by volume shifting and loop closure; (ii) The coarse-to-fine iterative closest point (ICP) algorithm, the SIFT odometry, and IMU odometry are combined to robustly and precisely estimate pose. In particular, ICP runs routinely to track the Kinect motion. If ICP fails in planar areas, the SIFT odometry provides incremental motion estimate. If both ICP and the SIFT odometry fail, e.g., upon abrupt motion or inadequate features, the incremental motion is estimated by the IMU. Additionally, the IMU also observes the roll and pitch angles which can reduce long-term drift of the sensor assembly. In experiments on a consumer laptop, our system estimates motion at 8Hz on average while integrating color images to the local map and saving volumes of meshes concurrently. Moreover, it is immune to tracking failures, and has smaller drift than the state-of-the-art systems in large scale reconstruction.

Drift reduction in strapdown airborne gravimetry using a simple thermal correction

DEFF Research Database (Denmark)

Becker, David; Nielsen, J. Emil; Ayres-Sampaio, Diogo

2015-01-01

Previous work has shown, that strapdown airborne gravimeters can have a comparable or even superior performance in the higher frequency domain (resolution of few kilometres), compared to classical stable-platform air gravimeters using springs, such as the LaCoste and Romberg (LCR) S-gravimeter. H...

IMU-to-Segment Assignment and Orientation Alignment for the Lower Body Using Deep Learning.

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Zimmermann, Tobias; Taetz, Bertram; Bleser, Gabriele

2018-01-19

Human body motion analysis based on wearable inertial measurement units (IMUs) receives a lot of attention from both the research community and the and industrial community. This is due to the significant role in, for instance, mobile health systems, sports and human computer interaction. In sensor based activity recognition, one of the major issues for obtaining reliable results is the sensor placement/assignment on the body. For inertial motion capture (joint kinematics estimation) and analysis, the IMU-to-segment (I2S) assignment and alignment are central issues to obtain biomechanical joint angles. Existing approaches for I2S assignment usually rely on hand crafted features and shallow classification approaches (e.g., support vector machines), with no agreement regarding the most suitable features for the assignment task. Moreover, estimating the complete orientation alignment of an IMU relative to the segment it is attached to using a machine learning approach has not been shown in literature so far. This is likely due to the high amount of training data that have to be recorded to suitably represent possible IMU alignment variations. In this work, we propose online approaches for solving the assignment and alignment tasks for an arbitrary amount of IMUs with respect to a biomechanical lower body model using a deep learning architecture and windows of 128 gyroscope and accelerometer data samples. For this, we combine convolutional neural networks (CNNs) for local filter learning with long-short-term memory (LSTM) recurrent networks as well as generalized recurrent units (GRUs) for learning time dynamic features. The assignment task is casted as a classification problem, while the alignment task is casted as a regression problem. In this framework, we demonstrate the feasibility of augmenting a limited amount of real IMU training data with simulated alignment variations and IMU data for improving the recognition/estimation accuracies. With the proposed

IMU-to-Segment Assignment and Orientation Alignment for the Lower Body Using Deep Learning

Directory of Open Access Journals (Sweden)

Tobias Zimmermann

2018-01-01

Full Text Available Human body motion analysis based on wearable inertial measurement units (IMUs receives a lot of attention from both the research community and the and industrial community. This is due to the significant role in, for instance, mobile health systems, sports and human computer interaction. In sensor based activity recognition, one of the major issues for obtaining reliable results is the sensor placement/assignment on the body. For inertial motion capture (joint kinematics estimation and analysis, the IMU-to-segment (I2S assignment and alignment are central issues to obtain biomechanical joint angles. Existing approaches for I2S assignment usually rely on hand crafted features and shallow classification approaches (e.g., support vector machines, with no agreement regarding the most suitable features for the assignment task. Moreover, estimating the complete orientation alignment of an IMU relative to the segment it is attached to using a machine learning approach has not been shown in literature so far. This is likely due to the high amount of training data that have to be recorded to suitably represent possible IMU alignment variations. In this work, we propose online approaches for solving the assignment and alignment tasks for an arbitrary amount of IMUs with respect to a biomechanical lower body model using a deep learning architecture and windows of 128 gyroscope and accelerometer data samples. For this, we combine convolutional neural networks (CNNs for local filter learning with long-short-term memory (LSTM recurrent networks as well as generalized recurrent units (GRUs for learning time dynamic features. The assignment task is casted as a classification problem, while the alignment task is casted as a regression problem. In this framework, we demonstrate the feasibility of augmenting a limited amount of real IMU training data with simulated alignment variations and IMU data for improving the recognition/estimation accuracies. With the

Radio/FADS/IMU integrated navigation for Mars entry

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Jiang, Xiuqiang; Li, Shuang; Huang, Xiangyu

2018-03-01

Supposing future orbiting and landing collaborative exploration mission as the potential project background, this paper addresses the issue of Mars entry integrated navigation using radio beacon, flush air data sensing system (FADS), and inertial measurement unit (IMU). The range and Doppler information sensed from an orbiting radio beacon, the dynamic pressure and heating data sensed from flush air data sensing system, and acceleration and attitude angular rate outputs from an inertial measurement unit are integrated in an unscented Kalman filter to perform state estimation and suppress the system and measurement noise. Computer simulations show that the proposed integrated navigation scheme can enhance the navigation accuracy, which enables precise entry guidance for the given Mars orbiting and landing collaborative exploration mission.

A Foot-Mounted Inertial Measurement Unit (IMU) Positioning Algorithm Based on Magnetic Constraint.

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Wang, Yan; Li, Xin; Zou, Jiaheng

2018-03-01

With the development of related applications, indoor positioning techniques have been more and more widely developed. Based on Wi-Fi, Bluetooth low energy (BLE) and geomagnetism, indoor positioning techniques often rely on the physical location of fingerprint information. The focus and difficulty of establishing the fingerprint database are in obtaining a relatively accurate physical location with as little given information as possible. This paper presents a foot-mounted inertial measurement unit (IMU) positioning algorithm under the loop closure constraint based on magnetic information. It can provide relatively reliable position information without maps and geomagnetic information and provides a relatively accurate coordinate for the collection of a fingerprint database. In the experiment, the features extracted by the multi-level Fourier transform method proposed in this paper are validated and the validity of loop closure matching is tested with a RANSAC-based method. Moreover, the loop closure detection results show that the cumulative error of the trajectory processed by the graph optimization algorithm is significantly suppressed, presenting a good accuracy. The average error of the trajectory under loop closure constraint is controlled below 2.15 m.

A Foot-Mounted Inertial Measurement Unit (IMU Positioning Algorithm Based on Magnetic Constraint

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Yan Wang

2018-03-01

Full Text Available With the development of related applications, indoor positioning techniques have been more and more widely developed. Based on Wi-Fi, Bluetooth low energy (BLE and geomagnetism, indoor positioning techniques often rely on the physical location of fingerprint information. The focus and difficulty of establishing the fingerprint database are in obtaining a relatively accurate physical location with as little given information as possible. This paper presents a foot-mounted inertial measurement unit (IMU positioning algorithm under the loop closure constraint based on magnetic information. It can provide relatively reliable position information without maps and geomagnetic information and provides a relatively accurate coordinate for the collection of a fingerprint database. In the experiment, the features extracted by the multi-level Fourier transform method proposed in this paper are validated and the validity of loop closure matching is tested with a RANSAC-based method. Moreover, the loop closure detection results show that the cumulative error of the trajectory processed by the graph optimization algorithm is significantly suppressed, presenting a good accuracy. The average error of the trajectory under loop closure constraint is controlled below 2.15 m.

Uticaj mesta ugradnje inercijalnog mernog bloka i akcelerometara na grešku u određivanju pozicije aviona / Size effect of the inertial measurement unit and inside IMU accelerometers on aircraft position error

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Slobodan Janićijević

2003-03-01

Full Text Available U ovom članku analiziran je uticaj mesta ugradnje inercijalnog mernog bloka (IMB u avionu i mesta ugradnje akcelerometara u IMB na tačnost određivanja pozicije pomoću bes-platformskog inercijalnog navigacijskog sistema (BINS. Pokazano je da se ovi uticaji ne mogu uvek zanemariti. Izračunata je ukupna greška u određivanju pozicije aviona ako se IMB ugrađuje van centra rotacije aviona, a akcelerometri van centra IMB. Predložena je optimalna orijentacija akcelerometara u IMB-u, kako bi se minimizirao uticaj ugradnje akcelerometara van centra IMB na tačnost određivanja pozicije aviona. Predložen je i način kompenzacije greške. / This paper analyzes the mounting offset size effect of the inertial measurement unit (IMU in aircraft and accelerometers mounting offset size effect in the IMU on the accuracy of strap down inertial navigation system (SDINS. It is also shown that these effects cannot be always neglected. The total size effect error for the IMU has been the computed. An accelerometers optimum orientation inside the IMU has been proposed to minimize size effects on the accuracy of navigation parameters. A manner to compensate these size effects has been proposed as well.

Analysis and Compensation of Modulation Angular Rate Error Based on Missile-Borne Rotation Semi-Strapdown Inertial Navigation System

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Jiayu Zhang

2018-05-01

Full Text Available The Semi-Strapdown Inertial Navigation System (SSINS provides a new solution to attitude measurement of a high-speed rotating missile. However, micro-electro-mechanical-systems (MEMS inertial measurement unit (MIMU outputs are corrupted by significant sensor errors. In order to improve the navigation precision, a rotation modulation technology method called Rotation Semi-Strapdown Inertial Navigation System (RSSINS is introduced into SINS. In fact, the stability of the modulation angular rate is difficult to achieve in a high-speed rotation environment. The changing rotary angular rate has an impact on the inertial sensor error self-compensation. In this paper, the influence of modulation angular rate error, including acceleration-deceleration process, and instability of the angular rate on the navigation accuracy of RSSINS is deduced and the error characteristics of the reciprocating rotation scheme are analyzed. A new compensation method is proposed to remove or reduce sensor errors so as to make it possible to maintain high precision autonomous navigation performance by MIMU when there is no external aid. Experiments have been carried out to validate the performance of the method. In addition, the proposed method is applicable for modulation angular rate error compensation under various dynamic conditions.

A flight test of the strapdown airborne gravimeter SGA-WZ in Greenland

DEFF Research Database (Denmark)

Zhao, Lei; Forsberg, René; Wu, Meiping

2015-01-01

-WZ strapdown airborne gravimeter in Greenland, in an area with good gravity coverage from earlier marine and airborne surveys. An overview of this new system SGA-WZ is given, including system design, sensor performance and data processing. The processing of the SGA-WZ includes a 160 s length finite impulse...

GEOREFERENCING IN GNSS-CHALLENGED ENVIRONMENT: INTEGRATING UWB AND IMU TECHNOLOGIES

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C. K. Toth

2017-05-01

Full Text Available Acquiring geospatial data in GNSS compromised environments remains a problem in mapping and positioning in general. Urban canyons, heavily vegetated areas, indoor environments represent different levels of GNSS signal availability from weak to no signal reception. Even outdoors, with multiple GNSS systems, with an ever-increasing number of satellites, there are many situations with limited or no access to GNSS signals. Independent navigation sensors, such as IMU can provide high-data rate information but their initial accuracy degrades quickly, as the measurement data drift over time unless positioning fixes are provided from another source. At The Ohio State University’s Satellite Positioning and Inertial Navigation (SPIN Laboratory, as one feasible solution, Ultra- Wideband (UWB radio units are used to aid positioning and navigating in GNSS compromised environments, including indoor and outdoor scenarios. Here we report about experiences obtained with georeferencing a pushcart based sensor system under canopied areas. The positioning system is based on UWB and IMU sensor integration, and provides sensor platform orientation for an electromagnetic inference (EMI sensor. Performance evaluation results are provided for various test scenarios, confirming acceptable results for applications where high accuracy is not required.

A cascaded two-step Kalman filter for estimation of human body segment orientation using MEMS-IMU.

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Zihajehzadeh, S; Loh, D; Lee, M; Hoskinson, R; Park, E J

2014-01-01

Orientation of human body segments is an important quantity in many biomechanical analyses. To get robust and drift-free 3-D orientation, raw data from miniature body worn MEMS-based inertial measurement units (IMU) should be blended in a Kalman filter. Aiming at less computational cost, this work presents a novel cascaded two-step Kalman filter orientation estimation algorithm. Tilt angles are estimated in the first step of the proposed cascaded Kalman filter. The estimated tilt angles are passed to the second step of the filter for yaw angle calculation. The orientation results are benchmarked against the ones from a highly accurate tactical grade IMU. Experimental results reveal that the proposed algorithm provides robust orientation estimation in both kinematically and magnetically disturbed conditions.

Performance Analysis of Measurement Inaccuracies of IMU/GPS on Airborne Repeat-pass Interferometric SAR in the Presence of Squint

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Deng Yuan

2014-08-01

Full Text Available In the MOtion COmpensation (MOCO approach to airborne repeat-pass interferometric Synthetic Aperture Radar (SAR based on motion measurement data, the measurement inaccuracies of Inertial Measurement Unit/Global Positioning System (IMU/GPS and the positioning errors of the target, which may contribute to the residual uncompensated motion errors, affect the imaging result and interferometric measurement. Considering the effects of the two types of error, this paper builds a mathematical model of residual motion errors in presence of squint, and analyzes the effects on the residual motion errors induced by the measurement inaccuracies of IMU/GPS and the positioning errors of the target. In particular, the effects of various measurement inaccuracies of IMU/GPS on interferometric SAR image quality, interferometric phase, and digital elevation model precision are disscussed. Moreover, the paper quantitatively researches the effects of residual motion errors on airborne repeat-pass interferometric SAR through theoretical and simulated analyses and provides theoretical bases for system design and signal processing.

Performance analysis of an IMU-augmented GNSS tracking system on board the MAIUS-1 sounding rocket

Science.gov (United States)

Braun, Benjamin; Grillenberger, Andreas; Markgraf, Markus

2018-05-01

Satellite navigation receivers are adequate tracking sensors for range safety of both orbital launch vehicles and suborbital sounding rockets. Due to high accuracy and its low system complexity, satellite navigation is seen as well-suited supplement or replacement of conventional tracking systems like radar. Having the well-known shortcomings of satellite navigation like deliberate or unintentional interferences in mind, it is proposed to augment the satellite navigation receiver by an inertial measurement unit (IMU) to enhance continuity and availability of localization. The augmented receiver is thus enabled to output at least an inertial position solution in case of signal outages. In a previous study, it was shown by means of simulation using the example of Ariane 5 that the performance of a low-grade microelectromechanical IMU is sufficient to bridge expected outages of some ten seconds, and still meeting the range safety requirements in effect. In this publication, these theoretical findings shall be substantiated by real flight data that were recorded on MAIUS-1, a sounding rocket launched from Esrange, Sweden, in early 2017. The analysis reveals that the chosen representative of a microelectromechanical IMU is suitable to bridge outages of up to thirty seconds.

MONITORING HIGH-FREQUENCY OCEAN SIGNALS USING LOW-COST GNSS/IMU BUOYS

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Y.-L. Huang

2016-06-01

Full Text Available In oceans there are different ocean signals covering the multi-frequencies including tsunami, meteotsunami, storm surge, as sea level change, and currents. These signals have the direct and significant impact on the economy and life of human-beings. Therefore, measuring ocean signals accurately becomes more and more important and necessary. Nowadays, there are many techniques and methods commonly used for monitoring oceans, but each has its limitation. For example, tide gauges only measure sea level relative to benchmarks and are disturbed unevenly, and satellite altimeter measurements are not continuous and inaccurate near coastal oceans. In addition, high-frequency ocean signals such as tsunami and meteotsunami cannot be sufficiently detected by 6-minutes tide gauge measurements or 10-day sampled altimetry data. Moreover, traditional accelerometer buoy is heavy, expensive and the low-frequency noise caused by the instrument is unavoidable. In this study, a small, low-cost and self-assembly autonomous Inertial Measurement Unit (IMU that independently collects continuous acceleration and angular velocity data is mounted on a GNSS buoy to provide the positions and tilts of the moving buoy. The main idea is to integrate the Differential GNSS (DGNSS or Precise Point Positioning (PPP solutions with IMU data, and then evaluate the performance by comparing with in situ tide gauges. The validation experiments conducted in the NCKU Tainan Hydraulics Laboratory showed that GNSS and IMU both can detect the simulated regular wave frequency and height, and the field experiments in the Anping Harbor, Tainan, Taiwan showed that the low-cost GNSS buoy has an excellent ability to observe significant wave heights in amplitude and frequency.

Tightly-Coupled Integration of Multi-GNSS Single-Frequency RTK and MEMS-IMU for Enhanced Positioning Performance.

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Li, Tuan; Zhang, Hongping; Niu, Xiaoji; Gao, Zhouzheng

2017-10-27

Dual-frequency Global Positioning System (GPS) Real-time Kinematics (RTK) has been proven in the past few years to be a reliable and efficient technique to obtain high accuracy positioning. However, there are still challenges for GPS single-frequency RTK, such as low reliability and ambiguity resolution (AR) success rate, especially in kinematic environments. Recently, multi-Global Navigation Satellite System (multi-GNSS) has been applied to enhance the RTK performance in terms of availability and reliability of AR. In order to further enhance the multi-GNSS single-frequency RTK performance in terms of reliability, continuity and accuracy, a low-cost micro-electro-mechanical system (MEMS) inertial measurement unit (IMU) is adopted in this contribution. We tightly integrate the single-frequency GPS/BeiDou/GLONASS and MEMS-IMU through the extended Kalman filter (EKF), which directly fuses the ambiguity-fixed double-differenced (DD) carrier phase observables and IMU data. A field vehicular test was carried out to evaluate the impacts of the multi-GNSS and IMU on the AR and positioning performance in different system configurations. Test results indicate that the empirical success rate of single-epoch AR for the tightly-coupled single-frequency multi-GNSS RTK/INS integration is over 99% even at an elevation cut-off angle of 40°, and the corresponding position time series is much more stable in comparison with the GPS solution. Besides, GNSS outage simulations show that continuous positioning with certain accuracy is possible due to the INS bridging capability when GNSS positioning is not available.

Pose estimation of surgical instrument using sensor data fusion with optical tracker and IMU based on Kalman filter

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Oh Hyunmin

2015-01-01

Full Text Available Tracking system is essential for Image Guided Surgery(IGS. The Optical Tracking Sensor(OTS has been widely used as tracking system for IGS due to its high accuracy and easy usage. However, OTS has a limit that tracking fails when occlusion of marker occurs. In this paper, sensor fusion with OTS and Inertial Measurement Unit(IMU is proposed to solve this problem. The proposed algorithm improves the accuracy of tracking system by eliminating scattering error of the sensor and supplements the disadvantages of OTS and IMU through sensor fusion based on Kalman filter. Also, coordinate axis calibration method that improves the accuracy is introduced. The performed experiment verifies the effectualness of the proposed algorithm.

FDIR for the IMU Component of AOCS Systems

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Maurício N. Pontuschka

2014-01-01

Full Text Available The main objective of this paper is the study of a FDIR for an IMU aiming at space applications with focus on the gyro signal analysis and the tests of the filtering algorithms. The algorithms have been tested by using lab data provided by the DMC LABSIM (Physical’s Simulation Laboratory of the Space Mechanics and Control Division of INPE. The results have demonstrated good agreement with the concepts applied in this study. Automatic detection procedures are very important in the characterization of occurrence, definition of criteria, and device types in the scenario of AOCS FDIR. An IMU comprised of four gyros in a tetrahedral configuration is one of the assumed components for the AOCS (attitude and orbit control subsystem considered in this work. The types of failures considered in this paper are the step abrupt change, ramp/drift/slow, stuck, cyclic, erratic, spike, and finally the stuck for variance alteration noise. An appropriate algorithm for the automatic detection of each type of fault is developed. The approach includes the mapping capability of fault event indicators to the IMU. This mapping is very important in the characterization of the occurrence, definition of criteria, and device types as well as associated fault identification for an AOCS.

Effect of SOS-induced levels of imuABC on spontaneous and damage-induced mutagenesis in Caulobacter crescentus.

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Alves, Ingrid R; Lima-Noronha, Marco A; Silva, Larissa G; Fernández-Silva, Frank S; Freitas, Aline Luiza D; Marques, Marilis V; Galhardo, Rodrigo S

2017-11-01

imuABC (imuAB dnaE2) genes are responsible for SOS-mutagenesis in Caulobacter crescentus and other bacterial species devoid of umuDC. In this work, we have constructed operator-constitutive mutants of the imuABC operon. We used this genetic tool to investigate the effect of SOS-induced levels of these genes upon both spontaneous and damage-induced mutagenesis. We showed that constitutive expression of imuABC does not increase spontaneous or damage-induced mutagenesis, nor increases cellular resistance to DNA-damaging agents. Nevertheless, the presence of the operator-constitutive mutation rescues mutagenesis in a recA background, indicating that imuABC are the only genes required at SOS-induced levels for translesion synthesis (TLS) in C. crescentus. Furthermore, these data also show that TLS mediated by ImuABC does not require RecA, unlike umuDC-dependent mutagenesis in E. coli. Copyright © 2017 Elsevier B.V. All rights reserved.

A Multi-Sensor Fusion MAV State Estimation from Long-Range Stereo, IMU, GPS and Barometric Sensors.

Science.gov (United States)

Song, Yu; Nuske, Stephen; Scherer, Sebastian

2016-12-22

State estimation is the most critical capability for MAV (Micro-Aerial Vehicle) localization, autonomous obstacle avoidance, robust flight control and 3D environmental mapping. There are three main challenges for MAV state estimation: (1) it can deal with aggressive 6 DOF (Degree Of Freedom) motion; (2) it should be robust to intermittent GPS (Global Positioning System) (even GPS-denied) situations; (3) it should work well both for low- and high-altitude flight. In this paper, we present a state estimation technique by fusing long-range stereo visual odometry, GPS, barometric and IMU (Inertial Measurement Unit) measurements. The new estimation system has two main parts, a stochastic cloning EKF (Extended Kalman Filter) estimator that loosely fuses both absolute state measurements (GPS, barometer) and the relative state measurements (IMU, visual odometry), and is derived and discussed in detail. A long-range stereo visual odometry is proposed for high-altitude MAV odometry calculation by using both multi-view stereo triangulation and a multi-view stereo inverse depth filter. The odometry takes the EKF information (IMU integral) for robust camera pose tracking and image feature matching, and the stereo odometry output serves as the relative measurements for the update of the state estimation. Experimental results on a benchmark dataset and our real flight dataset show the effectiveness of the proposed state estimation system, especially for the aggressive, intermittent GPS and high-altitude MAV flight.

Magnetometer-Augmented IMU Simulator: In-Depth Elaboration

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Thomas Brunner

2015-03-01

Full Text Available The location of objects is a growing research topic due, for instance, to the expansion of civil drones or intelligent vehicles. This expansion was made possible through the development of microelectromechanical systems (MEMS, inexpensive and miniaturized inertial sensors. In this context, this article describes the development of a new simulator which generates sensor measurements, giving a specific input trajectory. This will allow the comparison of pose estimation algorithms. To develop this simulator, the measurement equations of every type of sensor have to be analytically determined. To achieve this objective, classical kinematic equations are used for the more common sensors, i.e., accelerometers and rate gyroscopes. As nowadays, the MEMS inertial measurement units (IMUs are generally magnetometer-augmented, an absolute world magnetic model is implemented. After the determination of the perfect measurement (through the error-free sensor models, realistic error models are developed to simulate real IMU behavior. Finally, the developed simulator is subjected to different validation tests.

Monocular Camera/IMU/GNSS Integration for Ground Vehicle Navigation in Challenging GNSS Environments

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Dennis Akos

2012-03-01

Full Text Available Low-cost MEMS-based IMUs, video cameras and portable GNSS devices are commercially available for automotive applications and some manufacturers have already integrated such facilities into their vehicle systems. GNSS provides positioning, navigation and timing solutions to users worldwide. However, signal attenuation, reflections or blockages may give rise to positioning difficulties. As opposed to GNSS, a generic IMU, which is independent of electromagnetic wave reception, can calculate a high-bandwidth navigation solution, however the output from a self-contained IMU accumulates errors over time. In addition, video cameras also possess great potential as alternate sensors in the navigation community, particularly in challenging GNSS environments and are becoming more common as options in vehicles. Aiming at taking advantage of these existing onboard technologies for ground vehicle navigation in challenging environments, this paper develops an integrated camera/IMU/GNSS system based on the extended Kalman filter (EKF. Our proposed integration architecture is examined using a live dataset collected in an operational traffic environment. The experimental results demonstrate that the proposed integrated system provides accurate estimations and potentially outperforms the tightly coupled GNSS/IMU integration in challenging environments with sparse GNSS observations.

Monocular camera/IMU/GNSS integration for ground vehicle navigation in challenging GNSS environments.

Science.gov (United States)

Chu, Tianxing; Guo, Ningyan; Backén, Staffan; Akos, Dennis

2012-01-01

Low-cost MEMS-based IMUs, video cameras and portable GNSS devices are commercially available for automotive applications and some manufacturers have already integrated such facilities into their vehicle systems. GNSS provides positioning, navigation and timing solutions to users worldwide. However, signal attenuation, reflections or blockages may give rise to positioning difficulties. As opposed to GNSS, a generic IMU, which is independent of electromagnetic wave reception, can calculate a high-bandwidth navigation solution, however the output from a self-contained IMU accumulates errors over time. In addition, video cameras also possess great potential as alternate sensors in the navigation community, particularly in challenging GNSS environments and are becoming more common as options in vehicles. Aiming at taking advantage of these existing onboard technologies for ground vehicle navigation in challenging environments, this paper develops an integrated camera/IMU/GNSS system based on the extended Kalman filter (EKF). Our proposed integration architecture is examined using a live dataset collected in an operational traffic environment. The experimental results demonstrate that the proposed integrated system provides accurate estimations and potentially outperforms the tightly coupled GNSS/IMU integration in challenging environments with sparse GNSS observations.

Monocular Camera/IMU/GNSS Integration for Ground Vehicle Navigation in Challenging GNSS Environments

Science.gov (United States)

Chu, Tianxing; Guo, Ningyan; Backén, Staffan; Akos, Dennis

2012-01-01

Low-cost MEMS-based IMUs, video cameras and portable GNSS devices are commercially available for automotive applications and some manufacturers have already integrated such facilities into their vehicle systems. GNSS provides positioning, navigation and timing solutions to users worldwide. However, signal attenuation, reflections or blockages may give rise to positioning difficulties. As opposed to GNSS, a generic IMU, which is independent of electromagnetic wave reception, can calculate a high-bandwidth navigation solution, however the output from a self-contained IMU accumulates errors over time. In addition, video cameras also possess great potential as alternate sensors in the navigation community, particularly in challenging GNSS environments and are becoming more common as options in vehicles. Aiming at taking advantage of these existing onboard technologies for ground vehicle navigation in challenging environments, this paper develops an integrated camera/IMU/GNSS system based on the extended Kalman filter (EKF). Our proposed integration architecture is examined using a live dataset collected in an operational traffic environment. The experimental results demonstrate that the proposed integrated system provides accurate estimations and potentially outperforms the tightly coupled GNSS/IMU integration in challenging environments with sparse GNSS observations. PMID:22736999

A new calibration method for tri-axial field sensors in strap-down navigation systems

International Nuclear Information System (INIS)

Li, Xiang; Li, Zhi

2012-01-01

This paper presents a novel calibration method for tri-axial field sensors, such as magnetometers and accelerometers, in strap-down navigation systems. Strap-down tri-axial sensors have been widely used as they have the advantages of small size and low cost, but they need to be calibrated in order to ensure their accuracy. The most commonly used calibration method for a tri-axial field sensor is based on ellipsoid fitting, which has no requirement for external references. However, the self-calibration based on ellipsoid fitting is unable to determine and compensate the mutual misalignment between different sensors in a multi-sensor system. Therefore, a novel calibration method that employs the invariance of the dot product of two constant vectors is introduced in this paper. The proposed method, which is named dot product invariance method, brings a complete solution for the error model of tri-axial field sensors, and can solve the problem of alignment in a multi-sensor system. Its effectiveness and superiority over the ellipsoid fitting method are illustrated by numerical simulations, and its application on a digital magnetic compass shows significant enhancement of the heading accuracy. (paper)

DNA Polymerases ImuC and DinB Are Involved in DNA Alkylation Damage Tolerance in Pseudomonas aeruginosa and Pseudomonas putida.

Science.gov (United States)

Jatsenko, Tatjana; Sidorenko, Julia; Saumaa, Signe; Kivisaar, Maia

2017-01-01

Translesion DNA synthesis (TLS), facilitated by low-fidelity polymerases, is an important DNA damage tolerance mechanism. Here, we investigated the role and biological function of TLS polymerase ImuC (former DnaE2), generally present in bacteria lacking DNA polymerase V, and TLS polymerase DinB in response to DNA alkylation damage in Pseudomonas aeruginosa and P. putida. We found that TLS DNA polymerases ImuC and DinB ensured a protective role against N- and O-methylation induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in both P. aeruginosa and P. putida. DinB also appeared to be important for the survival of P. aeruginosa and rapidly growing P. putida cells in the presence of methyl methanesulfonate (MMS). The role of ImuC in protection against MMS-induced damage was uncovered under DinB-deficient conditions. Apart from this, both ImuC and DinB were critical for the survival of bacteria with impaired base excision repair (BER) functions upon alkylation damage, lacking DNA glycosylases AlkA and/or Tag. Here, the increased sensitivity of imuCdinB double deficient strains in comparison to single mutants suggested that the specificity of alkylated DNA lesion bypass of DinB and ImuC might also be different. Moreover, our results demonstrated that mutagenesis induced by MMS in pseudomonads was largely ImuC-dependent. Unexpectedly, we discovered that the growth temperature of bacteria affected the efficiency of DinB and ImuC in ensuring cell survival upon alkylation damage. Taken together, the results of our study disclosed the involvement of ImuC in DNA alkylation damage tolerance, especially at low temperatures, and its possible contribution to the adaptation of pseudomonads upon DNA alkylation damage via increased mutagenesis.

Integrity monitoring of vehicle positioning in urban environment using RTK-GNSS, IMU and speedometer

Science.gov (United States)

El-Mowafy, Ahmed; Kubo, Nobuaki

2017-05-01

Continuous and trustworthy positioning is a critical capability for advanced driver assistance systems (ADAS). To achieve continuous positioning, methods such as global navigation satellite systems real-time kinematic (RTK), Doppler-based positioning, and positioning using low-cost inertial measurement unit (IMU) with car speedometer data are combined in this study. To ensure reliable positioning, the system should have integrity monitoring above a certain level, such as 99%. Achieving this level when combining different types of measurements that have different characteristics and different types of errors is a challenge. In this study, a novel integrity monitoring approach is presented for the proposed integrated system. A threat model of the measurements of the system components is discussed, which includes both the nominal performance and possible fault modes. A new protection level is presented to bound the maximum directional position error. The proposed approach was evaluated through a kinematic test in an urban area in Japan with a focus on horizontal positioning. Test results show that by integrating RTK, Doppler with IMU/speedometer, 100% positioning availability was achieved. The integrity monitoring availability was assessed and found to meet the target value where the position errors were bounded by the protection level, which was also less than an alert level, indicating the effectiveness of the proposed approach.

Integrity monitoring of vehicle positioning in urban environment using RTK-GNSS, IMU and speedometer

International Nuclear Information System (INIS)

El-Mowafy, Ahmed; Kubo, Nobuaki

2017-01-01

Continuous and trustworthy positioning is a critical capability for advanced driver assistance systems (ADAS). To achieve continuous positioning, methods such as global navigation satellite systems real-time kinematic (RTK), Doppler-based positioning, and positioning using low-cost inertial measurement unit (IMU) with car speedometer data are combined in this study. To ensure reliable positioning, the system should have integrity monitoring above a certain level, such as 99%. Achieving this level when combining different types of measurements that have different characteristics and different types of errors is a challenge. In this study, a novel integrity monitoring approach is presented for the proposed integrated system. A threat model of the measurements of the system components is discussed, which includes both the nominal performance and possible fault modes. A new protection level is presented to bound the maximum directional position error. The proposed approach was evaluated through a kinematic test in an urban area in Japan with a focus on horizontal positioning. Test results show that by integrating RTK, Doppler with IMU/speedometer, 100% positioning availability was achieved. The integrity monitoring availability was assessed and found to meet the target value where the position errors were bounded by the protection level, which was also less than an alert level, indicating the effectiveness of the proposed approach. (paper)

Optimized Design of the SGA-WZ Strapdown Airborne Gravimeter Temperature Control System

Directory of Open Access Journals (Sweden)

Juliang Cao

2015-12-01

Full Text Available The temperature control system is one of the most important subsystems of the strapdown airborne gravimeter. Because the quartz flexible accelerometer based on springy support technology is the core sensor in the strapdown airborne gravimeter and the magnet steel in the electromagnetic force equilibrium circuits of the quartz flexible accelerometer is greatly affected by temperature, in order to guarantee the temperature control precision and minimize the effect of temperature on the gravimeter, the SGA-WZ temperature control system adopts a three-level control method. Based on the design experience of the SGA-WZ-01, the SGA-WZ-02 temperature control system came out with a further optimized design. In 1st level temperature control, thermoelectric cooler is used to conquer temperature change caused by hot weather. The experiments show that the optimized stability of 1st level temperature control is about 0.1 °C and the max cool down capability is about 10 °C. The temperature field is analyzed in the 2nd and 3rd level temperature control using the finite element analysis software ANSYS. The 2nd and 3rd level temperature control optimization scheme is based on the foundation of heat analysis. The experimental results show that static accuracy of SGA-WZ-02 reaches 0.21 mGal/24 h, with internal accuracy being 0.743 mGal/4.8 km and external accuracy being 0.37 mGal/4.8 km compared with the result of the GT-2A, whose internal precision is superior to 1 mGal/4.8 km and all of them are better than those in SGA-WZ-01.

Pattern recognition in cyclic and discrete skills performance from inertial measurement units

NARCIS (Netherlands)

Seifert, Ludovic; L'Hermette, Maxime; Komar, John; Orth, Dominic; Mell, Florian; Merriaux, Pierre; Grenet, Pierre; Caritu, Yanis; Hérault, Romain; Dovgalecs, Vladislavs; Davids, Keith

2014-01-01

The aim of this study is to compare and validate an Inertial Measurement Unit (IMU) relative to an optic system, and to propose methods for pattern recognition to capture behavioural dynamics during sport performance. IMU validation was conducted by comparing the motions of the two arms of a

A study of redundancy management strategy for tetrad strap-down inertial systems. [error detection codes

Science.gov (United States)

Hruby, R. J.; Bjorkman, W. S.; Schmidt, S. F.; Carestia, R. A.

1979-01-01

Algorithms were developed that attempt to identify which sensor in a tetrad configuration has experienced a step failure. An algorithm is also described that provides a measure of the confidence with which the correct identification was made. Experimental results are presented from real-time tests conducted on a three-axis motion facility utilizing an ortho-skew tetrad strapdown inertial sensor package. The effects of prediction errors and of quantization on correct failure identification are discussed as well as an algorithm for detecting second failures through prediction.

Ka-band InSAR Imaging and Analysis Based on IMU Data

Directory of Open Access Journals (Sweden)

Shi Jun

2014-02-01

Full Text Available Compared with other bands, the millimeter wave Interferometric Synthetic Aperture Radar (InSAR has high accuracy and small size, which is a hot topic in InSAR research. On the other hand, shorter wavelength causes difficulties in 2D imaging and interferometric phase extraction. In this study, the imaging and phase performance of the streaming Back Projection (BP method combined with IMU data are analyzed and discussed on the basis of actual Ka-band InSAR data. It is found that because the wavelength of the Ka-band is short, it is more sensitive to the antenna phase-center history. To ensure the phase-preserving capacity, the IMU data must be used with accurate motion error compensation. Furthermore, during data processing, we verify the flat-earth-removing capacity of the BP algorithm that calculates and compensates the master and slave antenna phase centers individually.

THERMAL PROTECTION AND THERMAL STABILIZATION OF FIBER-OPTICAL GYROSCOPE INCLUDED IN STRAPDOWN INERTIAL NAVIGATION SYSTEM

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D. S. Gromov

2014-03-01

Full Text Available It is known, that temperature perturbations and thermal modes have significant influence on the accuracy of a fiber-optical gyroscope. Nowadays, thermal perturbations are among the main problems in the field of navigation accuracy. Review of existing methods for decrease of temperature influences on the accuracy of a strapdown inertial navigation system with fiberoptical gyros showed, that the usage of constructive and compensation methods only is insufficient and, therefore, thermostabilization is required. Reversible thermostabilization system is offered, its main executive elements are thermoelectric modules (Peltier’s modules, heat transfer from which is provided by heatsinks at work surfaces of modules. This variant of thermostabilization maintenance is considered; Peltier’s modules and temperature sensors for the system are chosen. Parameters of heatsinks for heat transfer intensification are calculated. Fans for necessary air circulation in the device are chosen and thickness of thermal isolation is calculated. Calculations of thermal modes of navigation system with thermostabilization are made in modern software Autodesk Simulation CFD. Comparison of results for present and previous researches and calculations shows essential decrease in gradients of temperature on gyro surfaces and better uniformity of temperature field in the whole device. Conclusions about efficiency of the given method usage in view of accuracy improvement of navigation system are made. Thermostabilization provision of a strapdown inertial navigation system with fiberoptical gyros is proved. Thermostabilization application in combination with compensational methods can reach a necessary accuracy of navigation system.

Implementation of an IMU Aided Image Stacking Algorithm in a Digital Camera for Unmanned Aerial Vehicles

Directory of Open Access Journals (Sweden)

Ahmad Audi

2017-07-01

Full Text Available Images acquired with a long exposure time using a camera embedded on UAVs (Unmanned Aerial Vehicles exhibit motion blur due to the erratic movements of the UAV. The aim of the present work is to be able to acquire several images with a short exposure time and use an image processing algorithm to produce a stacked image with an equivalent long exposure time. Our method is based on the feature point image registration technique. The algorithm is implemented on the light-weight IGN (Institut national de l’information géographique camera, which has an IMU (Inertial Measurement Unit sensor and an SoC (System on Chip/FPGA (Field-Programmable Gate Array. To obtain the correct parameters for the resampling of the images, the proposed method accurately estimates the geometrical transformation between the first and the N-th images. Feature points are detected in the first image using the FAST (Features from Accelerated Segment Test detector, then homologous points on other images are obtained by template matching using an initial position benefiting greatly from the presence of the IMU sensor. The SoC/FPGA in the camera is used to speed up some parts of the algorithm in order to achieve real-time performance as our ultimate objective is to exclusively write the resulting image to save bandwidth on the storage device. The paper includes a detailed description of the implemented algorithm, resource usage summary, resulting processing time, resulting images and block diagrams of the described architecture. The resulting stacked image obtained for real surveys does not seem visually impaired. An interesting by-product of this algorithm is the 3D rotation estimated by a photogrammetric method between poses, which can be used to recalibrate in real time the gyrometers of the IMU. Timing results demonstrate that the image resampling part of this algorithm is the most demanding processing task and should also be accelerated in the FPGA in future work.

Implementation of an IMU Aided Image Stacking Algorithm in a Digital Camera for Unmanned Aerial Vehicles.

Science.gov (United States)

Audi, Ahmad; Pierrot-Deseilligny, Marc; Meynard, Christophe; Thom, Christian

2017-07-18

Images acquired with a long exposure time using a camera embedded on UAVs (Unmanned Aerial Vehicles) exhibit motion blur due to the erratic movements of the UAV. The aim of the present work is to be able to acquire several images with a short exposure time and use an image processing algorithm to produce a stacked image with an equivalent long exposure time. Our method is based on the feature point image registration technique. The algorithm is implemented on the light-weight IGN (Institut national de l'information géographique) camera, which has an IMU (Inertial Measurement Unit) sensor and an SoC (System on Chip)/FPGA (Field-Programmable Gate Array). To obtain the correct parameters for the resampling of the images, the proposed method accurately estimates the geometrical transformation between the first and the N -th images. Feature points are detected in the first image using the FAST (Features from Accelerated Segment Test) detector, then homologous points on other images are obtained by template matching using an initial position benefiting greatly from the presence of the IMU sensor. The SoC/FPGA in the camera is used to speed up some parts of the algorithm in order to achieve real-time performance as our ultimate objective is to exclusively write the resulting image to save bandwidth on the storage device. The paper includes a detailed description of the implemented algorithm, resource usage summary, resulting processing time, resulting images and block diagrams of the described architecture. The resulting stacked image obtained for real surveys does not seem visually impaired. An interesting by-product of this algorithm is the 3D rotation estimated by a photogrammetric method between poses, which can be used to recalibrate in real time the gyrometers of the IMU. Timing results demonstrate that the image resampling part of this algorithm is the most demanding processing task and should also be accelerated in the FPGA in future work.

Android Platform for Realtime Gait Tracking Using Inertial Measurement Units.

Science.gov (United States)

Aqueveque, Pablo; Sobarzo, Sergio; Saavedra, Francisco; Maldonado, Claudio; Gómez, Britam

2016-06-13

One of the most important movements performed by the humans is gait. Biomechanical Gait analysis is usually by optical capture systems. However, such systems are expensive and sensitive to light and obstacles. In order to reduce those costs a system based on Inertial Measurements Units (IMU) is proposed. IMU are a good option to make movement analisys indoor with a low post-processing data, allowing to connect those systems to an Android platform. The design is based on two elements: a) The IMU sensors and the b) Android device. The IMU sensor is simple, small (35 x 35 mm), portable and autonomous (7.8 hrs). A resolution of 0.01° in their measurements is obtained, and sends data via Bluetooth link. The Android application works for Android 4.2 or higher, and it is compatible with Bluetooth devices 2.0 or higher. Three IMU sensors send data to a Tablet wirelessly, in order to evaluate the angles evolution for each joint of the leg (hip, knee and ankle). This information is used to calculate gait index and evaluate the gait quality online during the physical therapist is working with the patient.

IMU-Based Joint Angle Measurement for Gait Analysis

Directory of Open Access Journals (Sweden)

Thomas Seel

2014-04-01

Full Text Available This contribution is concerned with joint angle calculation based on inertial measurement data in the context of human motion analysis. Unlike most robotic devices, the human body lacks even surfaces and right angles. Therefore, we focus on methods that avoid assuming certain orientations in which the sensors are mounted with respect to the body segments. After a review of available methods that may cope with this challenge, we present a set of new methods for: (1 joint axis and position identification; and (2 flexion/extension joint angle measurement. In particular, we propose methods that use only gyroscopes and accelerometers and, therefore, do not rely on a homogeneous magnetic field. We provide results from gait trials of a transfemoral amputee in which we compare the inertial measurement unit (IMU-based methods to an optical 3D motion capture system. Unlike most authors, we place the optical markers on anatomical landmarks instead of attaching them to the IMUs. Root mean square errors of the knee flexion/extension angles are found to be less than 1° on the prosthesis and about 3° on the human leg. For the plantar/dorsiflexion of the ankle, both deviations are about 1°.

Stereo and IMU-Assisted Visual Odometry for Small Robots

Science.gov (United States)

2012-01-01

This software performs two functions: (1) taking stereo image pairs as input, it computes stereo disparity maps from them by cross-correlation to achieve 3D (three-dimensional) perception; (2) taking a sequence of stereo image pairs as input, it tracks features in the image sequence to estimate the motion of the cameras between successive image pairs. A real-time stereo vision system with IMU (inertial measurement unit)-assisted visual odometry was implemented on a single 750 MHz/520 MHz OMAP3530 SoC (system on chip) from TI (Texas Instruments). Frame rates of 46 fps (frames per second) were achieved at QVGA (Quarter Video Graphics Array i.e. 320 240), or 8 fps at VGA (Video Graphics Array 640 480) resolutions, while simultaneously tracking up to 200 features, taking full advantage of the OMAP3530's integer DSP (digital signal processor) and floating point ARM processors. This is a substantial advancement over previous work as the stereo implementation produces 146 Mde/s (millions of disparities evaluated per second) in 2.5W, yielding a stereo energy efficiency of 58.8 Mde/J, which is 3.75 better than prior DSP stereo while providing more functionality.

A Robust Vehicle Localization Approach Based on GNSS/IMU/DMI/LiDAR Sensor Fusion for Autonomous Vehicles

Directory of Open Access Journals (Sweden)

Xiaoli Meng

2017-09-01

Full Text Available Precise and robust localization in a large-scale outdoor environment is essential for an autonomous vehicle. In order to improve the performance of the fusion of GNSS (Global Navigation Satellite System/IMU (Inertial Measurement Unit/DMI (Distance-Measuring Instruments, a multi-constraint fault detection approach is proposed to smooth the vehicle locations in spite of GNSS jumps. Furthermore, the lateral localization error is compensated by the point cloud-based lateral localization method proposed in this paper. Experiment results have verified the algorithms proposed in this paper, which shows that the algorithms proposed in this paper are capable of providing precise and robust vehicle localization.

A Robust Vehicle Localization Approach Based on GNSS/IMU/DMI/LiDAR Sensor Fusion for Autonomous Vehicles.

Science.gov (United States)

Meng, Xiaoli; Wang, Heng; Liu, Bingbing

2017-09-18

Precise and robust localization in a large-scale outdoor environment is essential for an autonomous vehicle. In order to improve the performance of the fusion of GNSS (Global Navigation Satellite System)/IMU (Inertial Measurement Unit)/DMI (Distance-Measuring Instruments), a multi-constraint fault detection approach is proposed to smooth the vehicle locations in spite of GNSS jumps. Furthermore, the lateral localization error is compensated by the point cloud-based lateral localization method proposed in this paper. Experiment results have verified the algorithms proposed in this paper, which shows that the algorithms proposed in this paper are capable of providing precise and robust vehicle localization.

Rigorous Performance Evaluation of Smartphone GNSS/IMU Sensors for ITS Applications

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Vassilis Gikas

2016-08-01

Full Text Available With the rapid growth in smartphone technologies and improvement in their navigation sensors, an increasing amount of location information is now available, opening the road to the provision of new Intelligent Transportation System (ITS services. Current smartphone devices embody miniaturized Global Navigation Satellite System (GNSS, Inertial Measurement Unit (IMU and other sensors capable of providing user position, velocity and attitude. However, it is hard to characterize their actual positioning and navigation performance capabilities due to the disparate sensor and software technologies adopted among manufacturers and the high influence of environmental conditions, and therefore, a unified certification process is missing. This paper presents the analysis results obtained from the assessment of two modern smartphones regarding their positioning accuracy (i.e., precision and trueness capabilities (i.e., potential and limitations based on a practical but rigorous methodological approach. Our investigation relies on the results of several vehicle tracking (i.e., cruising and maneuvering tests realized through comparing smartphone obtained trajectories and kinematic parameters to those derived using a high-end GNSS/IMU system and advanced filtering techniques. Performance testing is undertaken for the HTC One S (Android and iPhone 5s (iOS. Our findings indicate that the deviation of the smartphone locations from ground truth (trueness deteriorates by a factor of two in obscured environments compared to those derived in open sky conditions. Moreover, it appears that iPhone 5s produces relatively smaller and less dispersed error values compared to those computed for HTC One S. Also, the navigation solution of the HTC One S appears to adapt faster to changes in environmental conditions, suggesting a somewhat different data filtering approach for the iPhone 5s. Testing the accuracy of the accelerometer and gyroscope sensors for a number of

Validation of an inertial measurement unit for the measurement of jump count and height.

Science.gov (United States)

MacDonald, Kerry; Bahr, Roald; Baltich, Jennifer; Whittaker, Jackie L; Meeuwisse, Willem H

2017-05-01

To validate the use of an inertial measurement unit (IMU) for the collection of total jump count and assess the validity of an IMU for the measurement of jump height against 3-D motion analysis. Cross sectional validation study. 3D motion-capture laboratory and field based settings. Thirteen elite adolescent volleyball players. Participants performed structured drills, played a 4 set volleyball match and performed twelve counter movement jumps. Jump counts from structured drills and match play were validated against visual count from recorded video. Jump height during the counter movement jumps was validated against concurrent 3-D motion-capture data. The IMU device captured more total jumps (1032) than visual inspection (977) during match play. During structured practice, device jump count sensitivity was strong (96.8%) while specificity was perfect (100%). The IMU underestimated jump height compared to 3D motion-capture with mean differences for maximal and submaximal jumps of 2.5 cm (95%CI: 1.3 to 3.8) and 4.1 cm (3.1-5.1), respectively. The IMU offers a valid measuring tool for jump count. Although the IMU underestimates maximal and submaximal jump height, our findings demonstrate its practical utility for field-based measurement of jump load. Copyright © 2016 Elsevier Ltd. All rights reserved.

An IMU-to-Body Alignment Method Applied to Human Gait Analysis

Directory of Open Access Journals (Sweden)

Laura Susana Vargas-Valencia

2016-12-01

Full Text Available This paper presents a novel calibration procedure as a simple, yet powerful, method to place and align inertial sensors with body segments. The calibration can be easily replicated without the need of any additional tools. The proposed method is validated in three different applications: a computer mathematical simulation; a simplified joint composed of two semi-spheres interconnected by a universal goniometer; and a real gait test with five able-bodied subjects. Simulation results demonstrate that, after the calibration method is applied, the joint angles are correctly measured independently of previous sensor placement on the joint, thus validating the proposed procedure. In the cases of a simplified joint and a real gait test with human volunteers, the method also performs correctly, although secondary plane errors appear when compared with the simulation results. We believe that such errors are caused by limitations of the current inertial measurement unit (IMU technology and fusion algorithms. In conclusion, the presented calibration procedure is an interesting option to solve the alignment problem when using IMUs for gait analysis.

Front-Crawl Instantaneous Velocity Estimation Using a Wearable Inertial Measurement Unit

Directory of Open Access Journals (Sweden)

Kamiar Aminian

2012-09-01

Full Text Available Monitoring the performance is a crucial task for elite sports during both training and competition. Velocity is the key parameter of performance in swimming, but swimming performance evaluation remains immature due to the complexities of measurements in water. The purpose of this study is to use a single inertial measurement unit (IMU to estimate front crawl velocity. Thirty swimmers, equipped with an IMU on the sacrum, each performed four different velocity trials of 25 m in ascending order. A tethered speedometer was used as the velocity measurement reference. Deployment of biomechanical constraints of front crawl locomotion and change detection framework on acceleration signal paved the way for a drift-free integration of forward acceleration using IMU to estimate the swimmers velocity. A difference of 0.6 ± 5.4 cm·s−1 on mean cycle velocity and an RMS difference of 11.3 cm·s−1 in instantaneous velocity estimation were observed between IMU and the reference. The most important contribution of the study is a new practical tool for objective evaluation of swimming performance. A single body-worn IMU provides timely feedback for coaches and sport scientists without any complicated setup or restraining the swimmer’s natural technique.

Strapdown Airborne Gravimetry Quality Assessment Method Based on Single Survey Line Data: A Study by SGA-WZ02 Gravimeter

Science.gov (United States)

Wu, Meiping; Cao, Juliang; Zhang, Kaidong; Cai, Shaokun; Yu, Ruihang

2018-01-01

Quality assessment is an important part in the strapdown airborne gravimetry. Root mean square error (RMSE) evaluation method is a classical way to evaluate the gravimetry quality, but classical evaluation methods are preconditioned by extra flight or reference data. Thus, a method, which is able to largely conquer the premises of classical quality assessment methods and can be used in single survey line, has been developed in this paper. According to theoretical analysis, the method chooses the stability of two horizontal attitude angles, horizontal specific force and vertical specific force as the determinants of quality assessment method. The actual data, collected by SGA-WZ02 from 13 flights 21 lines in certain survey, was used to build the model and elaborate the method. To substantiate the performance of the quality assessment model, the model is applied in extra repeat line flights from two surveys. Compared with internal RMSE, standard deviation of assessment residuals are 0.23 mGal and 0.16 mGal in two surveys, which shows that the quality assessment method is reliable and stricter. The extra flights are not necessary by specially arranging the route of flights. The method, summarized from SGA-WZ02, is a feasible approach to assess gravimetry quality using single line data and is also suitable for other strapdown gravimeters. PMID:29373535

Attitude and gyro bias estimation by the rotation of an inertial measurement unit

International Nuclear Information System (INIS)

Wu, Zheming; Sun, Zhenguo; Zhang, Wenzeng; Chen, Qiang

2015-01-01

In navigation applications, the presence of an unknown bias in the measurement of rate gyros is a key performance-limiting factor. In order to estimate the gyro bias and improve the accuracy of attitude measurement, we proposed a new method which uses the rotation of an inertial measurement unit, which is independent from rigid body motion. By actively changing the orientation of the inertial measurement unit (IMU), the proposed method generates sufficient relations between the gyro bias and tilt angle (roll and pitch) error via ridge body dynamics, and the gyro bias, including the bias that causes the heading error, can be estimated and compensated. The rotation inertial measurement unit method makes the gravity vector measured from the IMU continuously change in a body-fixed frame. By theoretically analyzing the mathematic model, the convergence of the attitude and gyro bias to the true values is proven. The proposed method provides a good attitude estimation using only measurements from an IMU, when other sensors such as magnetometers and GPS are unreliable. The performance of the proposed method is illustrated under realistic robotic motions and the results demonstrate an improvement in the accuracy of the attitude estimation. (paper)

RECALMIN II. Eight years of hospitalisation in Internal Medicine Units (2007-2014). What has changed?

Science.gov (United States)

Zapatero-Gaviria, A; Barba-Martín, R; Canora Lebrato, J; Fernández-Pérez, C; Gómez-Huelgas, R; Bernal-Sobrino, J L; Díez-Manglano, J; Marco-Martínez, J; Elola-Somoza, F J

2017-11-01

To analyse the evolution of care provided by the internal medicine units (IMU) of the Spanish National Health System from 2007 to 2014. We analysed all discharges from the IMU of the Spanish National Health System in 2007 and 2014, using the Minimum Basic Data Set. We compared the risk factors by episode, mortality and readmissions between the two periods. We prepared specific fits for the risk for mortality and readmissions in heart failure, pneumonia and chronic obstructive pulmonary disease, as well as the Charlson index for all activity. Discharges from the IMU between the two periods increased 14%. The average patient age increased by 2.8 years (71.2±17.1 vs. 74±16.2; pde Medicina Interna (SEMI). All rights reserved.

Airborne Gravimetry Survey for the Marine Area of the United Arab Emirates

DEFF Research Database (Denmark)

Forsberg, René; Olesen, Arne Vestergaard; Alshamsi, Adel

2012-01-01

The Military Survey Department (MSD) of the United Arab Emirates (UAE) undertook an airborne gravity survey project for the marine area of the country in 2009, especially to strengthen the marine and coastal geoid in the near-shore regions. For the airborne gravity survey, 5 km spacing coast...... flight speed of 170 knots and a typical flight elevation of 900-1500 m, depending on weather conditions and topography. Gravity was measured with a ZLS-modified LaCoste and Romberg gravimeter (S-99), augmented with a Honeywell strap-down inertial navigation system unit. The estimated accuracy...

A Novel Vehicle Stationary Detection Utilizing Map Matching and IMU Sensors

Directory of Open Access Journals (Sweden)

Md. Syedul Amin

2014-01-01

Full Text Available Precise navigation is a vital need for many modern vehicular applications. The global positioning system (GPS cannot provide continuous navigation information in urban areas. The widely used inertial navigation system (INS can provide full vehicle state at high rates. However, the accuracy diverges quickly in low cost microelectromechanical systems (MEMS based INS due to bias, drift, noise, and other errors. These errors can be corrected in a stationary state. But detecting stationary state is a challenging task. A novel stationary state detection technique from the variation of acceleration, heading, and pitch and roll of an attitude heading reference system (AHRS built from the inertial measurement unit (IMU sensors is proposed. Besides, the map matching (MM algorithm detects the intersections where the vehicle is likely to stop. Combining these two results, the stationary state is detected with a smaller timing window of 3 s. A longer timing window of 5 s is used when the stationary state is detected only from the AHRS. The experimental results show that the stationary state is correctly identified and the position error is reduced to 90% and outperforms previously reported work. The proposed algorithm would help to reduce INS errors and enhance the performance of the navigation system.

Practical method for estimating road curvatures using onboard GPS and IMU equipment

Science.gov (United States)

Zamfir, S.; Drosescu, R.; Gaiginschi, R.

2016-08-01

This paper describes an experimental method to determine with high accuracy the curvature of a road segment, the turning radius of a car, and the discomfort level perceived by the passengers in the vehicle cabin when passing through a curve. For these experiments we used professional equipment provided with two GPS active antennas with 13 dB gain featuring non-contact 100 Hz speed and distance measurement, and a ten degree Inertial Measurement Unit (IMU) with dynamic orientation outputs. The same experimental measurements also usedthe low cost GPS equipment available on smartphones, domestic vehicle GPS devices, as well as an Arduino GPS shield in order to compare the results generated by professional equipment. The purpose of these experiments was also to establish if certain road curve sections were correctly executed in order to ensure the safety and comfort of passengers. Another use of the proposed method relates to the road accident reconstruction field, providing experts and forensics with an accurate method of measuring the roadway curvature at accident scenes or traffic events. The research and equipment described in this paper have been acquired and developed under a PhD studyand a European funded project won and elaborated by the authors.

Underground mine navigation using an integrated IMU/TOF system with unscented Kalman filter

CSIR Research Space (South Africa)

Hlophe, K

2011-07-01

Full Text Available & Factories of the Future Conference, 26-28 July 2011, Kuala Lumpur, Malaysia improve mine safety?, in 25th International Conference of CAD/CAM, Robotics & Factories of the Future, Pretoria, 2010. [2] J. J. Green and D. Vogt, Robot miner for low... Page 1 of 11 26th International Conference of CAD/CAM, Robotics & Factories of the Future Conference, 26-28 July 2011, Kuala Lumpur, Malaysia UNDERGROUND MINE NAVIGATION USING AN INTERGRATED IMU/TOF SYSTEM WITH UNSCENTED KALMAN FILTER...

Design considerations for a suboptimal Kalman filter

Science.gov (United States)

Difilippo, D. J.

1995-06-01

In designing a suboptimal Kalman filter, the designer must decide how to simplify the system error model without causing the filter estimation errors to increase to unacceptable levels. Deletion of certain error states and decoupling of error state dynamics are the two principal model simplifications that are commonly used in suboptimal filter design. For the most part, the decisions as to which error states can be deleted or decoupled are based on the designer's understanding of the physics of the particular system. Consequently, the details of a suboptimal design are usually unique to the specific application. In this paper, the process of designing a suboptimal Kalman filter is illustrated for the case of an airborne transfer-of-alignment (TOA) system used for synthetic aperture radar (SAR) motion compensation. In this application, the filter must continuously transfer the alignment of an onboard Doppler-damped master inertial navigation system (INS) to a strapdown navigator that processes information from a less accurate inertial measurement unit (IMU) mounted on the radar antenna. The IMU is used to measure spurious antenna motion during the SAR imaging interval, so that compensating phase corrections can be computed and applied to the radar returns, thereby presenting image degradation that would otherwise result from such motions. The principles of SAR are described in many references, for instance. The primary function of the TOA Kalman filter in a SAR motion compensation system is to control strapdown navigator attitude errors, and to a less degree, velocity and heading errors. Unlike a classical navigation application, absolute positional accuracy is not important. The motion compensation requirements for SAR imaging are discussed in some detail. This TOA application is particularly appropriate as a vehicle for discussing suboptimal filter design, because the system contains features that can be exploited to allow both deletion and decoupling of error

A Wavelet-based method for processing signal of fog in strap-down inertial systems

Energy Technology Data Exchange (ETDEWEB)

Han, D.; Xiong, C.; Liu, H. [Huazhong University of Science & Technology, Wuhan (China)

2009-07-01

Fibre optical gyroscopes (FOGs) have been applied widely in many fields in contrast, with their counterparts such as mechanical gyroscopes and ring laser gyroscopes. The precision of FOG is affected significantly by bias drift, angle random walk temperature effects and noises. Especially, uncertain disturbances resulting from road irregularities often affect accuracy of strap-down inertial system (SINS). Hence, eliminating, uncertain disturbances from outputs of it FOG plays a crucial role to improve accuracy of SINS. This paper presents a wavelet-based method for denoising signals of FOGs in SINS used for exploring and rescuing robots in coal mines. Property of road irregularities in mines is taken into account as a key factor resulting in uncertain disturbances in this research. Both frequency band and amplitude of uncertain disturbances are introduced to choose filtering thresholds. Experimental results have demonstrated that the proposed method can efficiently eliminate uncertain disturbances due to road irregularities from outputs of FOGs and improve accuracy of surrogate data. It indicates that the proposed method has a significant potential in FOG-related applications.

IMU-based Real-time Pose Measurement system for Anterior Pelvic Plane in Total Hip Replacement Surgeries.

Science.gov (United States)

Zhe Cao; Shaojie Su; Hao Tang; Yixin Zhou; Zhihua Wang; Hong Chen

2017-07-01

With the aging of population, the number of Total Hip Replacement Surgeries (THR) increased year by year. In THR, inaccurate position of the implanted prosthesis may lead to the failure of the operation. In order to reduce the failure rate and acquire the real-time pose of Anterior Pelvic Plane (APP), we propose a measurement system in this paper. The measurement system includes two parts: Initial Pose Measurement Instrument (IPMI) and Real-time Pose Measurement Instrument (RPMI). IPMI is used to acquire the initial pose of the APP, and RPMI is used to estimate the real-time pose of the APP. Both are composed of an Inertial Measurement Unit (IMU) and magnetometer sensors. To estimate the attitude of the measurement system, the Extended Kalman Filter (EKF) is adopted in this paper. The real-time pose of the APP could be acquired together with the algorithm designed in the paper. The experiment results show that the Root Mean Square Error (RMSE) is within 1.6 degrees, which meets the requirement of THR operations.

An IMU-Aided Body-Shadowing Error Compensation Method for Indoor Bluetooth Positioning.

Science.gov (United States)

Deng, Zhongliang; Fu, Xiao; Wang, Hanhua

2018-01-20

Research on indoor positioning technologies has recently become a hotspot because of the huge social and economic potential of indoor location-based services (ILBS). Wireless positioning signals have a considerable attenuation in received signal strength (RSS) when transmitting through human bodies, which would cause significant ranging and positioning errors in RSS-based systems. This paper mainly focuses on the body-shadowing impairment of RSS-based ranging and positioning, and derives a mathematical expression of the relation between the body-shadowing effect and the positioning error. In addition, an inertial measurement unit-aided (IMU-aided) body-shadowing detection strategy is designed, and an error compensation model is established to mitigate the effect of body-shadowing. A Bluetooth positioning algorithm with body-shadowing error compensation (BP-BEC) is then proposed to improve both the positioning accuracy and the robustness in indoor body-shadowing environments. Experiments are conducted in two indoor test beds, and the performance of both the BP-BEC algorithm and the algorithms without body-shadowing error compensation (named no-BEC) is evaluated. The results show that the BP-BEC outperforms the no-BEC by about 60.1% and 73.6% in terms of positioning accuracy and robustness, respectively. Moreover, the execution time of the BP-BEC algorithm is also evaluated, and results show that the convergence speed of the proposed algorithm has an insignificant effect on real-time localization.

System and method for three-dimensional image reconstruction using an absolute orientation sensor

KAUST Repository

Giancola, Silvio

2018-01-18

A three-dimensional image reconstruction system includes an image capture device, an inertial measurement unit (IMU), and an image processor. The image capture device captures image data. The inertial measurement unit (IMU) is affixed to the image capture device and records IMU data associated with the image data. The image processor includes one or more processing units and memory for storing instructions that are executed by the one or more processing units, wherein the image processor receives the image data and the IMU data as inputs and utilizes the IMU data to pre-align the first image and the second image, and wherein the image processor utilizes a registration algorithm to register the pre-aligned first and second images.

An IMU-Aided Body-Shadowing Error Compensation Method for Indoor Bluetooth Positioning

Directory of Open Access Journals (Sweden)

Zhongliang Deng

2018-01-01

Full Text Available Research on indoor positioning technologies has recently become a hotspot because of the huge social and economic potential of indoor location-based services (ILBS. Wireless positioning signals have a considerable attenuation in received signal strength (RSS when transmitting through human bodies, which would cause significant ranging and positioning errors in RSS-based systems. This paper mainly focuses on the body-shadowing impairment of RSS-based ranging and positioning, and derives a mathematical expression of the relation between the body-shadowing effect and the positioning error. In addition, an inertial measurement unit-aided (IMU-aided body-shadowing detection strategy is designed, and an error compensation model is established to mitigate the effect of body-shadowing. A Bluetooth positioning algorithm with body-shadowing error compensation (BP-BEC is then proposed to improve both the positioning accuracy and the robustness in indoor body-shadowing environments. Experiments are conducted in two indoor test beds, and the performance of both the BP-BEC algorithm and the algorithms without body-shadowing error compensation (named no-BEC is evaluated. The results show that the BP-BEC outperforms the no-BEC by about 60.1% and 73.6% in terms of positioning accuracy and robustness, respectively. Moreover, the execution time of the BP-BEC algorithm is also evaluated, and results show that the convergence speed of the proposed algorithm has an insignificant effect on real-time localization.

Application of inertial measuring unit in air navigation for ALS and DAP

African Journals Online (AJOL)

This article describes the inertial measuring device IMU, as well as its use in airborne laser scanning and digital aerial photography. This device is used during the operation of a scanning unit and an aerial photo camera. The structure of an additional connection for a digital video camera is proposed, which will record video ...

Intent of Study on the Use of a Dual Airborne Laser Scanner (ALS) in Conjunction with a Tactical Grade Inertial Measurement Unit (IMU) for Unmanned Aerial Vehicle (UAV) Navigation and Mapping in Unknown, Non-Global Positioning System (GPS), Environments

Science.gov (United States)

2006-08-05

ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) AF Office of Scientific h Researc 875 N. Randolph St. Room 3112 11. SPONSOR/MONITOR’S REPORT...the process is often time-consuming and expensive. As the IMU market is experiencing a migration trend towards Micro Electro-Mechanical System (MEMS

Comparative performance analysis of M-IMU/EMG and voice user interfaces for assistive robots.

Science.gov (United States)

Laureiti, Clemente; Cordella, Francesca; di Luzio, Francesco Scotto; Saccucci, Stefano; Davalli, Angelo; Sacchetti, Rinaldo; Zollo, Loredana

2017-07-01

People with a high level of disability experience great difficulties to perform activities of daily living and resort to their residual motor functions in order to operate assistive devices. The commercially available interfaces used to control assistive manipulators are typically based on joysticks and can be used only by subjects with upper-limb residual mobilities. Many other solutions can be found in the literature, based on the use of multiple sensory systems for detecting the human motion intention and state. Some of them require a high cognitive workload for the user. Some others are more intuitive and easy to use but have not been widely investigated in terms of usability and user acceptance. The objective of this work is to propose an intuitive and robust user interface for assistive robots, not obtrusive for the user and easily adaptable for subjects with different levels of disability. The proposed user interface is based on the combination of M-IMU and EMG for the continuous control of an arm-hand robotic system by means of M-IMUs. The system has been experimentally validated and compared to a standard voice interface. Sixteen healthy subjects volunteered to participate in the study: 8 subjects used the combined M-IMU/EMG robot control, and 8 subjects used the voice control. The arm-hand robotic system made of the KUKA LWR 4+ and the IH2 Azzurra hand was controlled to accomplish the daily living task of drinking. Performance indices and evaluation scales were adopted to assess performance of the two interfaces.

Integrated navigation method of a marine strapdown inertial navigation system using a star sensor

International Nuclear Information System (INIS)

Wang, Qiuying; Diao, Ming; Gao, Wei; Zhu, Minghong; Xiao, Shu

2015-01-01

This paper presents an integrated navigation method of the strapdown inertial navigation system (SINS) using a star sensor. According to the principle of SINS, its own navigation information contains an error that increases with time. Hence, the inertial attitude matrix from the star sensor is introduced as the reference information to correct the SINS increases error. For the integrated navigation method, the vehicle’s attitude can be obtained in two ways: one is calculated from SINS; the other, which we have called star sensor attitude, is obtained as the product between the SINS position and the inertial attitude matrix from the star sensor. Therefore, the SINS position error is introduced in the star sensor attitude error. Based on the characteristics of star sensor attitude error and the mathematical derivation, the SINS navigation errors can be obtained by the coupling calculation between the SINS attitude and the star sensor attitude. Unlike several current techniques, the navigation process of this method is non-radiating and invulnerable to jamming. The effectiveness of this approach was demonstrated by simulation and experimental study. The results show that this integrated navigation method can estimate the attitude error and the position error of SINS. Therefore, the SINS navigation accuracy is improved. (paper)

Validity of Hip-worn Inertial Measurement Unit Compared to Jump Mat for Jump Height Measurement in Adolescents.

Science.gov (United States)

Rantalainen, T; Hesketh, K D; Rodda, C; Duckham, R L

2018-06-16

Jump tests assess lower body power production capacity, and can be used to evaluate athletic ability and development during growth. Wearable inertial measurement units (IMU) seem to offer a feasible alternative to laboratory-based equipment for jump height assessments. Concurrent validity of these devices for jump height assessments has only been established in adults. Therefore, the purpose of this study was to evaluate the concurrent validity of IMU-based jump height estimate compared to contact mat-based jump height estimate in adolescents. Ninety-five adolescents (10-13 years-of-age; girls N=41, height = 154 (SD 9) cm, weight = 44 (11) kg; boys N=54, height=156 (10) cm, weight = 46 (13) kg) completed three counter-movement jumps for maximal jump height on a contact mat. Inertial recordings (accelerations, rotations) were concurrently recorded with a hip-worn IMU (sampling at 256 Hz). Jump height was evaluated based on flight time. The mean IMU-derived jump height was 27.1 (SD 3.8) cm, and the corresponding mean jump-mat-derived value was 21.5 (3.4) cm. While a significant 26% mean difference was observed between the methods (5.5 [95% limits of agreement 2.2 to 8.9] cm, p = 0.006), the correspondence between methods was excellent (ICC = 0.89). The difference between methods was weakly positively associated with jump height (r = 0.28, P = 0.007). Take-off velocity derived jump height was also explored but produced only fair congruence. In conclusion, IMU-derived jump height exhibited excellent congruence to contact mat-based jump height and therefore presents a feasible alternative for jump height assessments in adolescents. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Cervical Coupling Motion Characteristics in Healthy People Using a Wireless Inertial Measurement Unit

Directory of Open Access Journals (Sweden)

Hyunho Kim

2013-01-01

Full Text Available Objective. The objectives were to show the feasibility of a wireless microelectromechanical system inertial measurement unit (MEMS-IMU to assess the time-domain characteristics of cervical motion that are clinically useful to evaluate cervical spine movement. Methods. Cervical spine movements were measured in 18 subjects with wireless IMUs. All rotation data are presented in the Euler angle system. Amount of coupling motions was evaluated by calculating the average angle ratio and the maximum angle ratio of the coupling motion to the primary motion. Reliability is presented with intraclass correlation coefficients (ICC. Results. Entire time-domain characteristics of cervical motion were measured with developed MEMS-IMU system. Cervical range of motion (CROM and coupling motion range were measured with high ICCs. The acquired data and calculated parameters had similar tendency with the previous studies. Conclusions. We evaluated cervical motion with economic system using a wireless IMU of high reliability. We could directly measure the three-dimensional cervical motion in degrees in realtime. The characteristics measured by this system may provide a diagnostic basis for structural or functional dysfunction of cervical spine. This system is also useful to demonstrate the effectiveness of any intervention such as conventional medical treatment, and Korean medical treatment, exercise therapy.

Thermal assessment of sunlight impinging on OSIRIS-REx OCAMS PolyCam, OTES, and IMU-sunshade MLI blankets in flight

Science.gov (United States)

Choi, Michael K.

2017-09-01

The NASA Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) spacecraft was successfully launched into orbit on September 8, 2016. It is traveling to a near-Earth asteroid (101955) Bennu, study it in detail, and bring back a pristine sample to Earth for scientific analyses. At the Outbound Cruise nominal spacecraft attitude, with Sun on +X, sunlight impinges on the OSIRIS-REx camera suite (OCAMS) PolyCam sunshade multilayer insulation (MLI) with microporous black polytetrafluoroethylene (PTFE), a portion of the PolyCam optics support tube (MLI with germanium black Kapton (GBK)), a portion of the OSIRIS-REx Thermal Emission Spectrometer (OTES) sunshade (MLI with GBK), the Inertia Measurement Unit (IMU) sunshade (MLI with GBK), and the OSIRIS-REx Laser Altimeter (OLA) sunshade (MLI with GBK). Sunlight is reflected or scattered by the above MLIs to the other components on the forward (+Z) deck. It illuminates the forward deck. A detailed thermal assessment on the solar impingement has been performed for the Proximity Ops at the asteroid, Touch-and-Go sample acquisition, and Return Cruise mission phases.

An accurate calibration method for accelerometer nonlinear scale factor on a low-cost three-axis turntable

International Nuclear Information System (INIS)

Pan, Jianye; Zhang, Chunxi; Cai, Qingzhong

2014-01-01

Strapdown inertial navigation system (SINS) requirements are very demanding on gyroscopes and accelerometers as well as on calibration. To improve the accuracy of SINS, high-accuracy calibration is needed. Adding the accelerometer nonlinear scale factor into the model and reducing estimation errors is essential for improving calibration methods. In this paper, the inertial navigation error model is simplified, including only velocity and tilt errors. Based on the simplified error model, the relationship between the navigation errors (the rates of change of velocity errors) and the inertial measurement unit (IMU) calibration parameters is presented. A tracking model is designed to estimate the rates of change of velocity errors. With a special calibration procedure consisting of six rotation sequences, the accelerometer nonlinear scale factor errors can be computed by the estimates of the rates of change of velocity errors. Simulation and laboratory test results show that the accelerometer nonlinear scale factor can be calibrated with satisfactory accuracy on a low-cost three-axis turntable in several minutes. The comparison with the traditional calibration method highlights the superior performance of the proposed calibration method without precise orientation control. In addition, the proposed calibration method saves a lot of time in comparison with the multi-position calibration method. (paper)

System and method for three-dimensional image reconstruction using an absolute orientation sensor

KAUST Repository

Giancola, Silvio; Ghanem, Bernard; Schneider, Jens; Wonka, Peter

2018-01-01

A three-dimensional image reconstruction system includes an image capture device, an inertial measurement unit (IMU), and an image processor. The image capture device captures image data. The inertial measurement unit (IMU) is affixed to the image

IMU Calibration and Validation in a Factory, Remote on Land and at Sea

DEFF Research Database (Denmark)

Jørgensen, Martin Juhl; Paccagnan, Dario; Poulsen, Niels Kjølstad

2014-01-01

relevance for gyro-compassing grade optical gyroscopes and force-rebalanced pendulous accelerometers: Scale factor, bias and sensor axes misalignments. Focus is on low-dynamic marine applications e.g., subsea construction and survey. Two different methods of calibration are investigated: Kalman smoothing...... using an Aided Inertial Navigation System (AINS) framework, augmenting the error state Kalman filter (ESKF) to include the full set of IMU calibration parameters and a least squares approach, where the calibration parameters are determined by minimizing the magnitude of the INS error differential...... equation output. A method of evaluating calibrations is introduced and discussed. The two calibration methods are evaluated for factory use and results compared to a legacy proprietary method as well as in-field calibration/verification on land and at sea. The calibration methods shows similar navigation...

A Damping Grid Strapdown Inertial Navigation System Based on a Kalman Filter for Ships in Polar Regions.

Science.gov (United States)

Huang, Weiquan; Fang, Tao; Luo, Li; Zhao, Lin; Che, Fengzhu

2017-07-03

The grid strapdown inertial navigation system (SINS) used in polar navigation also includes three kinds of periodic oscillation errors as common SINS are based on a geographic coordinate system. Aiming ships which have the external information to conduct a system reset regularly, suppressing the Schuler periodic oscillation is an effective way to enhance navigation accuracy. The Kalman filter based on the grid SINS error model which applies to the ship is established in this paper. The errors of grid-level attitude angles can be accurately estimated when the external velocity contains constant error, and then correcting the errors of the grid-level attitude angles through feedback correction can effectively dampen the Schuler periodic oscillation. The simulation results show that with the aid of external reference velocity, the proposed external level damping algorithm based on the Kalman filter can suppress the Schuler periodic oscillation effectively. Compared with the traditional external level damping algorithm based on the damping network, the algorithm proposed in this paper can reduce the overshoot errors when the state of grid SINS is switched from the non-damping state to the damping state, and this effectively improves the navigation accuracy of the system.

Tracking 3D Moving Objects Based on GPS/IMU Navigation Solution, Laser Scanner Point Cloud and GIS Data

Directory of Open Access Journals (Sweden)

Siavash Hosseinyalamdary

2015-07-01

Full Text Available Monitoring vehicular road traffic is a key component of any autonomous driving platform. Detecting moving objects, and tracking them, is crucial to navigating around objects and predicting their locations and trajectories. Laser sensors provide an excellent observation of the area around vehicles, but the point cloud of objects may be noisy, occluded, and prone to different errors. Consequently, object tracking is an open problem, especially for low-quality point clouds. This paper describes a pipeline to integrate various sensor data and prior information, such as a Geospatial Information System (GIS map, to segment and track moving objects in a scene. We show that even a low-quality GIS map, such as OpenStreetMap (OSM, can improve the tracking accuracy, as well as decrease processing time. A bank of Kalman filters is used to track moving objects in a scene. In addition, we apply non-holonomic constraint to provide a better orientation estimation of moving objects. The results show that moving objects can be correctly detected, and accurately tracked, over time, based on modest quality Light Detection And Ranging (LiDAR data, a coarse GIS map, and a fairly accurate Global Positioning System (GPS and Inertial Measurement Unit (IMU navigation solution.

Study of the Navigation Method for a Snake Robot Based on the Kinematics Model with MEMS IMU

Science.gov (United States)

Dou, Lihua; Su, Zhong; Liu, Ning

2018-01-01

A snake robot is a type of highly redundant mobile robot that significantly differs from a tracked robot, wheeled robot and legged robot. To address the issue of a snake robot performing self-localization in the application environment without assistant orientation, an autonomous navigation method is proposed based on the snake robot’s motion characteristic constraints. The method realized the autonomous navigation of the snake robot with non-nodes and an external assistant using its own Micro-Electromechanical-Systems (MEMS) Inertial-Measurement-Unit (IMU). First, it studies the snake robot’s motion characteristics, builds the kinematics model, and then analyses the motion constraint characteristics and motion error propagation properties. Second, it explores the snake robot’s navigation layout, proposes a constraint criterion and the fixed relationship, and makes zero-state constraints based on the motion features and control modes of a snake robot. Finally, it realizes autonomous navigation positioning based on the Extended-Kalman-Filter (EKF) position estimation method under the constraints of its motion characteristics. With the self-developed snake robot, the test verifies the proposed method, and the position error is less than 5% of Total-Traveled-Distance (TDD). In a short-distance environment, this method is able to meet the requirements of a snake robot in order to perform autonomous navigation and positioning in traditional applications and can be extended to other familiar multi-link robots. PMID:29547515

Study of the Navigation Method for a Snake Robot Based on the Kinematics Model with MEMS IMU.

Science.gov (United States)

Zhao, Xu; Dou, Lihua; Su, Zhong; Liu, Ning

2018-03-16

A snake robot is a type of highly redundant mobile robot that significantly differs from a tracked robot, wheeled robot and legged robot. To address the issue of a snake robot performing self-localization in the application environment without assistant orientation, an autonomous navigation method is proposed based on the snake robot's motion characteristic constraints. The method realized the autonomous navigation of the snake robot with non-nodes and an external assistant using its own Micro-Electromechanical-Systems (MEMS) Inertial-Measurement-Unit (IMU). First, it studies the snake robot's motion characteristics, builds the kinematics model, and then analyses the motion constraint characteristics and motion error propagation properties. Second, it explores the snake robot's navigation layout, proposes a constraint criterion and the fixed relationship, and makes zero-state constraints based on the motion features and control modes of a snake robot. Finally, it realizes autonomous navigation positioning based on the Extended-Kalman-Filter (EKF) position estimation method under the constraints of its motion characteristics. With the self-developed snake robot, the test verifies the proposed method, and the position error is less than 5% of Total-Traveled-Distance (TDD). In a short-distance environment, this method is able to meet the requirements of a snake robot in order to perform autonomous navigation and positioning in traditional applications and can be extended to other familiar multi-link robots.

Use of LiDAR to Assist in Delineating Waters of the United States, Including Wetlands

Science.gov (United States)

2014-03-01

components: a mounting platform, a laser and scanning mirror, an inertial measurement unit (IMU), a global positioning system (GPS) antenna and...including but not limited to TIFF, ASC , IMG, and KML files or compressed as a KMZ file. These files are quickly imported and viewed using GIS such as...sediment transport processes and hydraulics. Sedimentology 56:2024–2043. Hogg, A., and J. Holland. 2008. An evaluation of DEMs derived from LiDAR

Indoor integrated navigation and synchronous data acquisition method for Android smartphone

Science.gov (United States)

Hu, Chunsheng; Wei, Wenjian; Qin, Shiqiao; Wang, Xingshu; Habib, Ayman; Wang, Ruisheng

2015-08-01

Smartphones are widely used at present. Most smartphones have cameras and kinds of sensors, such as gyroscope, accelerometer and magnet meter. Indoor navigation based on smartphone is very important and valuable. According to the features of the smartphone and indoor navigation, a new indoor integrated navigation method is proposed, which uses MEMS (Micro-Electro-Mechanical Systems) IMU (Inertial Measurement Unit), camera and magnet meter of smartphone. The proposed navigation method mainly involves data acquisition, camera calibration, image measurement, IMU calibration, initial alignment, strapdown integral, zero velocity update and integrated navigation. Synchronous data acquisition of the sensors (gyroscope, accelerometer and magnet meter) and the camera is the base of the indoor navigation on the smartphone. A camera data acquisition method is introduced, which uses the camera class of Android to record images and time of smartphone camera. Two kinds of sensor data acquisition methods are introduced and compared. The first method records sensor data and time with the SensorManager of Android. The second method realizes open, close, data receiving and saving functions in C language, and calls the sensor functions in Java language with JNI interface. A data acquisition software is developed with JDK (Java Development Kit), Android ADT (Android Development Tools) and NDK (Native Development Kit). The software can record camera data, sensor data and time at the same time. Data acquisition experiments have been done with the developed software and Sumsang Note 2 smartphone. The experimental results show that the first method of sensor data acquisition is convenient but lost the sensor data sometimes, the second method is much better in real-time performance and much less in data losing. A checkerboard image is recorded, and the corner points of the checkerboard are detected with the Harris method. The sensor data of gyroscope, accelerometer and magnet meter have

Study of the Navigation Method for a Snake Robot Based on the Kinematics Model with MEMS IMU

Directory of Open Access Journals (Sweden)

Xu Zhao

2018-03-01

Full Text Available A snake robot is a type of highly redundant mobile robot that significantly differs from a tracked robot, wheeled robot and legged robot. To address the issue of a snake robot performing self-localization in the application environment without assistant orientation, an autonomous navigation method is proposed based on the snake robot’s motion characteristic constraints. The method realized the autonomous navigation of the snake robot with non-nodes and an external assistant using its own Micro-Electromechanical-Systems (MEMS Inertial-Measurement-Unit (IMU. First, it studies the snake robot’s motion characteristics, builds the kinematics model, and then analyses the motion constraint characteristics and motion error propagation properties. Second, it explores the snake robot’s navigation layout, proposes a constraint criterion and the fixed relationship, and makes zero-state constraints based on the motion features and control modes of a snake robot. Finally, it realizes autonomous navigation positioning based on the Extended-Kalman-Filter (EKF position estimation method under the constraints of its motion characteristics. With the self-developed snake robot, the test verifies the proposed method, and the position error is less than 5% of Total-Traveled-Distance (TDD. In a short-distance environment, this method is able to meet the requirements of a snake robot in order to perform autonomous navigation and positioning in traditional applications and can be extended to other familiar multi-link robots.

PUSHBROOM HYPERSPECTRAL IMAGING FROM AN UNMANNED AIRCRAFT SYSTEM (UAS) – GEOMETRIC PROCESSINGWORKFLOW AND ACCURACY ASSESSMENT

KAUST Repository

Turner, D.; Lucieer, A.; McCabe, Matthew; Parkes, Stephen; Clarke, I.

2017-01-01

dual frequency Global Navigation Satellite System (GNSS) receiver, an Inertial Measurement Unit (IMU), and Machine Vision Camera (MVC) were used for attitude and position determination. For the nano-Hyperspec, a navigation grade GNSS system and IMU

[RECALMIN. Patient care in the internal medicine units of the Spanish national health system].

Science.gov (United States)

Zapatero Gaviria, A; Barba Martín, R; Román Sánchez, P; Casariego Vales, E; Diez Manglano, J; García Cors, M; Jusdado Ruiz-Capillas, J J; Suárez Fernández, C; Bernal, J L; Elola Somoza, F J

2016-05-01

To perform a situation analysis of the care provided by internal medicine units (IMUs) in Spain and to develop, based on this analysis, proposals for improving the quality of care in these units. A descriptive, cross-sectional study of the IMUs of general acute care hospitals of the Spanish National Health System (SNHS), with data referring to 2013. The study variables were collected via an ad hoc questionnaire. Of the total 260hospitals identified in the SNHS, 142responses were obtained from 139hospitals throughout Spain, which represents 53.5% of the IMUs in the SNHS. The mean number of internists per IMU was 14±8, with a mean rate of 7.2±3.3 internists per 100,000 inhabitants. In 2013, the average number of hospital discharges from the IMU was 2,987±2,066, and those discharged by internists was 232±107. Sixty-one percent of the IMUs had implemented an interconsultation unit, and 41% had implemented a systematic care program for complex chronic patients. Thirty-three percent of the IMUs conducted multidisciplinary rounds, and 60% of these IMUs planned the discharge. The 2013 RECALMIN survey revealed a number of important aspects of the organisation, structure and management of IMUs. The remarkable variability in the indicators of structure, activity and management probably reflect significant differences in efficiency and productivity, which therefore provide significant room for improvement. Copyright © 2016 Elsevier España, S.L.U. y Sociedad Española de Medicina Interna (SEMI). All rights reserved.

Flight envelope protection system for unmanned aerial vehicles

KAUST Repository

Claudel, Christian G.; Shaqura, Mohammad

2016-01-01

Systems and methods to protect the flight envelope in both manual flight and flight by a commercial autopilot are provided. A system can comprise: an inertial measurement unit (IMU); a computing device in data communication with the IMU

Sampling and Control Circuit Board for an Inertial Measurement Unit

Science.gov (United States)

Chelmins, David T (Inventor); Powis, Richard T., Jr. (Inventor); Sands, Obed (Inventor)

2016-01-01

A circuit board that serves as a control and sampling interface to an inertial measurement unit ("IMU") is provided. The circuit board is also configured to interface with a local oscillator and an external trigger pulse. The circuit board is further configured to receive the external trigger pulse from an external source that time aligns the local oscillator and initiates sampling of the inertial measurement device for data at precise time intervals based on pulses from the local oscillator. The sampled data may be synchronized by the circuit board with other sensors of a navigation system via the trigger pulse.

Analysis of ergonomic and unergonomic human lifting behaviors by using Inertial Measurement Units

Directory of Open Access Journals (Sweden)

Kuschan Jan

2017-03-01

Full Text Available This paper presents an analysis of two distinct human lifting movements regarding acceleration and angular velocity. For the first movement, the ergonomic one, the test persons produced the lifting power by squatting down, bending at the hips and knees only. Whereas performing the unergonomic one they bent forward lifting the box mainly with their backs. The measurements were taken by using a vest equipped with five Inertial Measurement Units (IMU with 9 Dimensions of Freedom (DOF each. In the following the IMU data captured for these two movements will be evaluated using statistics and visualized. It will also be discussed with respect to their suitability as features for further machine learning classifications. The reason for observing these movements is that occupational diseases of the musculoskeletal system lead to a reduction of the workers’ quality of life and extra costs for companies. Therefore, a vest, called CareJack, was designed to give the worker a real-time feedback about his ergonomic state while working. The CareJack is an approach to reduce the risk of spinal and back diseases. This paper will also present the idea behind it as well as its main components.

Quantifying Stability Using Frequency Domain Data from Wireless Inertial Measurement Units

Directory of Open Access Journals (Sweden)

Stephen Slaughter

2013-06-01

Full Text Available The quantification of gait stability can provide valuable information when evaluating subjects for age related and neuromuscular disease changes. Using tri-axial inertial measurement units (IMU for acceleration and rotational data provide a non-linear profile for this type of movement. As subjects traverse various surfaces representing decreasing stability, the different phasing of gait data make comparisons difficult. By converting from time to frequency domain data, the phase effects can be ignored, allowing for significant correlations. In this study, 12 subjects provided gait information over various surfaces while wearing an IMU. Instabilities were determined by comparing frequency domain data over less stable surfaces to frequency domain data of neural network (NN models representing the normal gait for any given participant. Time dependent data from 2 axes of acceleration and 2 axes of rotation were converted using a discrete Fourier transform (FFT algorithm. The data over less stable surfaces were compared to the normal gait NN model by averaging the Pearson product moment correlation (r values. This provided a method to quantify the decreased stability. Data showed progressively decreasing correlation coefficient values as subjects encountered progressively less stable surface environments. This methodology has allowed for the quantification of instability in gait situations for application in real-time fall prevention situations.

Quantifying Stability Using Frequency Domain Data from Wireless Inertial Measurement Units

Directory of Open Access Journals (Sweden)

Stephen Slaughter

2012-08-01

Full Text Available The quantification of gait stability can provide valuable information when evaluating subjects for age related and neuromuscular disease changes. Using tri-axial inertial measurement units (IMU for acceleration and rotational data provide a non-linear profile for this type of movement. As subjects traverse various surfaces representing decreasing stability, the different phasing of gait data make comparisons difficult. By converting from time to frequency domain data, the phase effects can be ignored, allowing for significant correlations. In this study, 12 subjects provided gait information over various surfaces while wearing an IMU. Instabilities were determined by comparing frequency domain data over less stable surfaces to frequency domain data of neural network (NN models representing the normal gait for any given participant. Time dependent data from 2 axes of acceleration and 2 axes of rotation were converted using a discrete Fourier transform (FFT algorithm. The data over less stable surfaces were compared to the normal gait NN model by averaging the Pearson product moment correlation (r values. This provided a method to quantify the decreased stability. Data showed progressively decreasing correlation coefficient values as subjects encountered progressively less stable surface environments. This methodology has allowed for the quantification of instability in gait situations for application in real-time fall prevention situations.

Intelligent Behavioral Action Aiding for Improved Autonomous Image Navigation

Science.gov (United States)

2012-09-13

odometry, SICK laser scanning unit ( Lidar ), Inertial Measurement Unit (IMU) and ultrasonic distance measurement system (Figure 32). The Lidar , IMU...2010, July) GPS world. [Online]. http://www.gpsworld.com/tech-talk- blog/gnss-independent-navigation-solution-using-integrated- lidar -data-11378 [4...Milford, David McKinnon, Michael Warren, Gordon Wyeth, and Ben Upcroft, "Feature-based Visual Odometry and Featureless Place Recognition for SLAM in

Magnetic distortion in motion labs, implications for validating inertial magnetic sensors

NARCIS (Netherlands)

de Vries, W.H.; Veeger, H.E.J.; Baten, C.T.M.; Helm, F.C.

2009-01-01

Background: Ambulatory 3D orientation estimation with Inertial Magnetic Sensor Units (IMU's) use the earth magnetic field. The magnitude of distortion in orientation in a standard equipped motion lab and its effect on the accuracy of the orientation estimation with IMU's is addressed. Methods:

Magnetic distortion in motion labs, implications for validating inertial magnetic sensors.

NARCIS (Netherlands)

Vries, W.H. de; Veeger, H.E.; Baten, C.T.; Helm, F.C.T. van der

2009-01-01

BACKGROUND: Ambulatory 3D orientation estimation with Inertial Magnetic Sensor Units (IMU's) use the earth magnetic field. The magnitude of distortion in orientation in a standard equipped motion lab and its effect on the accuracy of the orientation estimation with IMU's is addressed. METHODS:

Validation of a High Sampling Rate Inertial Measurement Unit for Acceleration During Running.

Science.gov (United States)

Provot, Thomas; Chiementin, Xavier; Oudin, Emeric; Bolaers, Fabrice; Murer, Sébastien

2017-08-25

The musculo-skeletal response of athletes to various activities during training exercises has become a critical issue in order to optimize their performance and minimize injuries. However, dynamic and kinematic measures of an athlete's activity are generally limited by constraints in data collection and technology. Thus, the choice of reliable and accurate sensors is crucial for gathering data in indoor and outdoor conditions. The aim of this study is to validate the use of the accelerometer of a high sampling rate ( 1344 Hz ) Inertial Measurement Unit (IMU) in the frame of running activities. To this end, two validation protocols are imposed: a classical one on a shaker, followed by another one during running, the IMU being attached to a test subject. For each protocol, the response of the IMU Accelerometer (IMUA) is compared to a calibrated industrial accelerometer, considered as the gold standard for dynamic and kinematic data collection. The repeatability, impact of signal frequency and amplitude (on shaker) as well as the influence of speed (while running) are investigated. Results reveal that the IMUA exhibits good repeatability. Coefficient of Variation CV is 1 % 8.58 ± 0.06 m / s 2 on the shaker and 3 % 26.65 ± 0.69 m / s 2 while running. However, the shaker test shows that the IMUA is affected by the signal frequency (error exceeds 10 % beyond 80 Hz ), an observation confirmed by the running test. Nevertheless, the IMUA provides a reliable measure in the range 0-100 Hz, i.e., the most relevant part in the energy spectrum over the range 0-150 Hz during running. In our view, these findings emphasize the validity of IMUs for the measurement of acceleration during running.

An Accurate GPS-IMU/DR Data Fusion Method for Driverless Car Based on a Set of Predictive Models and Grid Constraints.

Science.gov (United States)

Wang, Shiyao; Deng, Zhidong; Yin, Gang

2016-02-24

A high-performance differential global positioning system (GPS)  receiver with real time kinematics provides absolute localization for driverless cars. However, it is not only susceptible to multipath effect but also unable to effectively fulfill precise error correction in a wide range of driving areas. This paper proposes an accurate GPS-inertial measurement unit (IMU)/dead reckoning (DR) data fusion method based on a set of predictive models and occupancy grid constraints. First, we employ a set of autoregressive and moving average (ARMA) equations that have different structural parameters to build maximum likelihood models of raw navigation. Second, both grid constraints and spatial consensus checks on all predictive results and current measurements are required to have removal of outliers. Navigation data that satisfy stationary stochastic process are further fused to achieve accurate localization results. Third, the standard deviation of multimodal data fusion can be pre-specified by grid size. Finally, we perform a lot of field tests on a diversity of real urban scenarios. The experimental results demonstrate that the method can significantly smooth small jumps in bias and considerably reduce accumulated position errors due to DR. With low computational complexity, the position accuracy of our method surpasses existing state-of-the-arts on the same dataset and the new data fusion method is practically applied in our driverless car.

An Accurate GPS-IMU/DR Data Fusion Method for Driverless Car Based on a Set of Predictive Models and Grid Constraints

Directory of Open Access Journals (Sweden)

Shiyao Wang

2016-02-01

Full Text Available A high-performance differential global positioning system (GPS  receiver with real time kinematics provides absolute localization for driverless cars. However, it is not only susceptible to multipath effect but also unable to effectively fulfill precise error correction in a wide range of driving areas. This paper proposes an accurate GPS–inertial measurement unit (IMU/dead reckoning (DR data fusion method based on a set of predictive models and occupancy grid constraints. First, we employ a set of autoregressive and moving average (ARMA equations that have different structural parameters to build maximum likelihood models of raw navigation. Second, both grid constraints and spatial consensus checks on all predictive results and current measurements are required to have removal of outliers. Navigation data that satisfy stationary stochastic process are further fused to achieve accurate localization results. Third, the standard deviation of multimodal data fusion can be pre-specified by grid size. Finally, we perform a lot of field tests on a diversity of real urban scenarios. The experimental results demonstrate that the method can significantly smooth small jumps in bias and considerably reduce accumulated position errors due to DR. With low computational complexity, the position accuracy of our method surpasses existing state-of-the-arts on the same dataset and the new data fusion method is practically applied in our driverless car.

A Highly Miniaturized, Wireless Inertial Measurement Unit for Characterizing the Dynamics of Pitched Baseballs and Softballs

Science.gov (United States)

McGinnis, Ryan S.; Perkins, Noel C.

2012-01-01

Baseball and softball pitch types are distinguished by the path and speed of the ball which, in turn, are determined by the angular velocity of the ball and the velocity of the ball center at the instant of release from the pitcher's hand. While radar guns and video-based motion capture (mocap) resolve ball speed, they provide little information about how the angular velocity of the ball and the velocity of the ball center develop and change during the throwing motion. Moreover, mocap requires measurements in a controlled lab environment and by a skilled technician. This study addresses these shortcomings by introducing a highly miniaturized, wireless inertial measurement unit (IMU) that is embedded in both baseballs and softballs. The resulting “ball-embedded” sensor resolves ball dynamics right on the field of play. Experimental results from ten pitches, five thrown by one softball pitcher and five by one baseball pitcher, demonstrate that this sensor technology can deduce the magnitude and direction of the ball's velocity at release to within 4.6% of measurements made using standard mocap. Moreover, the IMU directly measures the angular velocity of the ball, which further enables the analysis of different pitch types.

A Wearable Inertial Measurement Unit for Long-Term Monitoring in the Dependency Care Area

Directory of Open Access Journals (Sweden)

Andreu Català

2013-10-01

Full Text Available Human movement analysis is a field of wide interest since it enables the assessment of a large variety of variables related to quality of life. Human movement can be accurately evaluated through Inertial Measurement Units (IMU, which are wearable and comfortable devices with long battery life. The IMU’s movement signals might be, on the one hand, stored in a digital support, in which an analysis is performed a posteriori. On the other hand, the signal analysis might take place in the same IMU at the same time as the signal acquisition through online classifiers. The new sensor system presented in this paper is designed for both collecting movement signals and analyzing them in real-time. This system is a flexible platform useful for collecting data via a triaxial accelerometer, a gyroscope and a magnetometer, with the possibility to incorporate other information sources in real-time. A µSD card can store all inertial data and a Bluetooth module is able to send information to other external devices and receive data from other sources. The system presented is being used in the real-time detection and analysis of Parkinson’s disease symptoms, in gait analysis, and in a fall detection system.

Player Monitoring in Indoor Team Sports: Concurrent Validity of Inertial Measurement Units to Quantify Average and Peak Acceleration Values

Directory of Open Access Journals (Sweden)

Mareike Roell

2018-02-01

Full Text Available The increasing interest in assessing physical demands in team sports has led to the development of multiple sports related monitoring systems. Due to technical limitations, these systems primarily could be applied to outdoor sports, whereas an equivalent indoor locomotion analysis is not established yet. Technological development of inertial measurement units (IMU broadens the possibilities for player monitoring and enables the quantification of locomotor movements in indoor environments. The aim of the current study was to validate an IMU measuring by determining average and peak human acceleration under indoor conditions in team sport specific movements. Data of a single wearable tracking device including an IMU (Optimeye S5, Catapult Sports, Melbourne, Australia were compared to the results of a 3D motion analysis (MA system (Vicon Motion Systems, Oxford, UK during selected standardized movement simulations in an indoor laboratory (n = 56. A low-pass filtering method for gravity correction (LF and two sensor fusion algorithms for orientation estimation [Complementary Filter (CF, Kalman-Filter (KF] were implemented and compared with MA system data. Significant differences (p < 0.05 were found between LF and MA data but not between sensor fusion algorithms and MA. Higher precision and lower relative errors were found for CF (RMSE = 0.05; CV = 2.6% and KF (RMSE = 0.15; CV = 3.8% both compared to the LF method (RMSE = 1.14; CV = 47.6% regarding the magnitude of the resulting vector and strongly emphasize the implementation of orientation estimation to accurately describe human acceleration. Comparing both sensor fusion algorithms, CF revealed slightly lower errors than KF and additionally provided valuable information about positive and negative acceleration values in all three movement planes with moderate to good validity (CV = 3.9 – 17.8%. Compared to x- and y-axis superior results were found for the z-axis. These findings demonstrate that

A Highly Miniaturized, Wireless Inertial Measurement Unit for Characterizing the Dynamics of Pitched Baseballs and Softballs

Directory of Open Access Journals (Sweden)

Noel C. Perkins

2012-08-01

Full Text Available Baseball and softball pitch types are distinguished by the path and speed of the ball which, in turn, are determined by the angular velocity of the ball and the velocity of the ball center at the instant of release from the pitcher’s hand. While radar guns and video-based motion capture (mocap resolve ball speed, they provide little information about how the angular velocity of the ball and the velocity of the ball center develop and change during the throwing motion. Moreover, mocap requires measurements in a controlled lab environment and by a skilled technician. This study addresses these shortcomings by introducing a highly miniaturized, wireless inertial measurement unit (IMU that is embedded in both baseballs and softballs. The resulting “ball-embedded” sensor resolves ball dynamics right on the field of play. Experimental results from ten pitches, five thrown by one softball pitcher and five by one baseball pitcher, demonstrate that this sensor technology can deduce the magnitude and direction of the ball’s velocity at release to within 4.6% of measurements made using standard mocap. Moreover, the IMU directly measures the angular velocity of the ball, which further enables the analysis of different pitch types.

Classification of deadlift biomechanics with wearable inertial measurement units.

Science.gov (United States)

O'Reilly, Martin A; Whelan, Darragh F; Ward, Tomas E; Delahunt, Eamonn; Caulfield, Brian M

2017-06-14

The deadlift is a compound full-body exercise that is fundamental in resistance training, rehabilitation programs and powerlifting competitions. Accurate quantification of deadlift biomechanics is important to reduce the risk of injury and ensure training and rehabilitation goals are achieved. This study sought to develop and evaluate deadlift exercise technique classification systems utilising Inertial Measurement Units (IMUs), recording at 51.2Hz, worn on the lumbar spine, both thighs and both shanks. It also sought to compare classification quality when these IMUs are worn in combination and in isolation. Two datasets of IMU deadlift data were collected. Eighty participants first completed deadlifts with acceptable technique and 5 distinct, deliberately induced deviations from acceptable form. Fifty-five members of this group also completed a fatiguing protocol (3-Repition Maximum test) to enable the collection of natural deadlift deviations. For both datasets, universal and personalised random-forests classifiers were developed and evaluated. Personalised classifiers outperformed universal classifiers in accuracy, sensitivity and specificity in the binary classification of acceptable or aberrant technique and in the multi-label classification of specific deadlift deviations. Whilst recent research has favoured universal classifiers due to the reduced overhead in setting them up for new system users, this work demonstrates that such techniques may not be appropriate for classifying deadlift technique due to the poor accuracy achieved. However, personalised classifiers perform very well in assessing deadlift technique, even when using data derived from a single lumbar-worn IMU to detect specific naturally occurring technique mistakes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Validity and repeatability of inertial measurement units for measuring gait parameters.

Science.gov (United States)

Washabaugh, Edward P; Kalyanaraman, Tarun; Adamczyk, Peter G; Claflin, Edward S; Krishnan, Chandramouli

2017-06-01

Inertial measurement units (IMUs) are small wearable sensors that have tremendous potential to be applied to clinical gait analysis. They allow objective evaluation of gait and movement disorders outside the clinic and research laboratory, and permit evaluation on large numbers of steps. However, repeatability and validity data of these systems are sparse for gait metrics. The purpose of this study was to determine the validity and between-day repeatability of spatiotemporal metrics (gait speed, stance percent, swing percent, gait cycle time, stride length, cadence, and step duration) as measured with the APDM Opal IMUs and Mobility Lab system. We collected data on 39 healthy subjects. Subjects were tested over two days while walking on a standard treadmill, split-belt treadmill, or overground, with IMUs placed in two locations: both feet and both ankles. The spatiotemporal measurements taken with the IMU system were validated against data from an instrumented treadmill, or using standard clinical procedures. Repeatability and minimally detectable change (MDC) of the system was calculated between days. IMUs displayed high to moderate validity when measuring most of the gait metrics tested. Additionally, these measurements appear to be repeatable when used on the treadmill and overground. The foot configuration of the IMUs appeared to better measure gait parameters; however, both the foot and ankle configurations demonstrated good repeatability. In conclusion, the IMU system in this study appears to be both accurate and repeatable for measuring spatiotemporal gait parameters in healthy young adults. Copyright © 2017 Elsevier B.V. All rights reserved.

Painting recognition with smartphones equipped with inertial measurement unit

Science.gov (United States)

Masiero, Andrea; Guarnieri, Alberto; Pirotti, Francesco; Vettore, Antonio

2015-06-01

Recently, several works have been proposed in the literature to take advantage of the diffusion of smartphones to improve people experience during museum visits. The rationale is that of substituting traditional written/audio guides with interactive electronic guides usable on a mobile phone. Augmented reality systems are usually considered to make the use of such electronic guides more effective for the user. The main goal of such augmented reality system (i.e. providing the user with the information of his/her interest) is usually achieved by properly executing the following three tasks: recognizing the object of interest to the user, retrieving the most relevant information about it, properly presenting the retrieved information. This paper focuses on the first task: we consider the problem of painting recognition by means of measure- ments provided by a smartphone. We assume that the user acquires one image of the painting of interest with the standard camera of the device. This image is compared with a set of reference images of the museum objects in order to recognize the object of interest to the user. Since comparing images taken in different conditions can lead to unsatisfactory recognition results, the acquired image is typically properly transformed in order to improve the results of the recognition system: first, the system estimates the homography between properly matched features in the two images. Then, the user image is transformed accordingly to the estimated homography. Finally, it is compared with the reference one. This work proposes a novel method to exploit inertial measurement unit (IMU) measurements to improve the system performance, in particular in terms of computational load reduction: IMU measurements are exploited to reduce both the computational burden required to estimate the transformation to be applied to the user image, and the number of reference images to be compared with it.

IMU and Multiple RGB-D Camera Fusion for Assisting Indoor Stop-and-Go 3D Terrestrial Laser Scanning

Directory of Open Access Journals (Sweden)

Jacky C.K. Chow

2014-07-01

Full Text Available Autonomous Simultaneous Localization and Mapping (SLAM is an important topic in many engineering fields. Since stop-and-go systems are typically slow and full-kinematic systems may lack accuracy and integrity, this paper presents a novel hybrid “continuous stop-and-go” mobile mapping system called Scannect. A 3D terrestrial LiDAR system is integrated with a MEMS IMU and two Microsoft Kinect sensors to map indoor urban environments. The Kinects’ depth maps were processed using a new point-to-plane ICP that minimizes the reprojection error of the infrared camera and projector pair in an implicit iterative extended Kalman filter (IEKF. A new formulation of the 5-point visual odometry method is tightly coupled in the implicit IEKF without increasing the dimensions of the state space. The Scannect can map and navigate in areas with textureless walls and provides an effective means for mapping large areas with lots of occlusions. Mapping long corridors (total travel distance of 120 m took approximately 30 minutes and achieved a Mean Radial Spherical Error of 17 cm before smoothing or global optimization.

Noise reduction and estimation in multiple micro-electro-mechanical inertial systems

International Nuclear Information System (INIS)

Waegli, Adrian; Skaloud, Jan; Guerrier, Stéphane; Parés, Maria Eulàlia; Colomina, Ismael

2010-01-01

This research studies the reduction and the estimation of the noise level within a redundant configuration of low-cost (MEMS-type) inertial measurement units (IMUs). Firstly, independent observations between units and sensors are assumed and the theoretical decrease in the system noise level is analyzed in an experiment with four MEMS-IMU triads. Then, more complex scenarios are presented in which the noise level can vary in time and for each sensor. A statistical method employed for studying the volatility of financial markets (GARCH) is adapted and tested for the usage with inertial data. This paper demonstrates experimentally and through simulations the benefit of direct noise estimation in redundant IMU setups

Development of a 3D workspace shoulder assessment tool incorporating electromyography and an inertial measurement unit-a preliminary study.

Science.gov (United States)

Aslani, Navid; Noroozi, Siamak; Davenport, Philip; Hartley, Richard; Dupac, Mihai; Sewell, Philip

2018-06-01

Traditional shoulder range of movement (ROM) measurement tools suffer from inaccuracy or from long experimental setup times. Recently, it has been demonstrated that relatively low-cost wearable inertial measurement unit (IMU) sensors can overcome many of the limitations of traditional motion tracking systems. The aim of this study is to develop and evaluate a single IMU combined with an electromyography (EMG) sensor to monitor the 3D reachable workspace with simultaneous measurement of deltoid muscle activity across the shoulder ROM. Six volunteer subjects with healthy shoulders and one participant with a 'frozen' shoulder were recruited to the study. Arm movement in 3D space was plotted in spherical coordinates while the relative EMG intensity of any arm position is presented graphically. The results showed that there was an average ROM surface area of 27291 ± 538 deg 2 among all six healthy individuals and a ROM surface area of 13571 ± 308 deg 2 for the subject with frozen shoulder. All three sections of the deltoid show greater EMG activity at higher elevation angles. Using such tools enables individuals, surgeons and physiotherapists to measure the maximum envelope of motion in conjunction with muscle activity in order to provide an objective assessment of shoulder performance in the voluntary 3D workspace. Graphical abstract The aim of this study is to develop and evaluate a single IMU combined with an electromyography (EMG) sensor to monitor the 3D reachable workspace with simultaneous measurement of deltoid muscle activity across the shoulder ROM. The assessment tool consists of an IMU sensor, an EMG sensor, a microcontroller and a Bluetooth module. The assessment tool was attached to subjects arm. Individuals were instructed to move their arms with the elbow fully extended. They were then asked to provide the maximal voluntary elevation envelope of the arm in 3D space in multiple attempts starting from a small movement envelope going to the biggest

A novel redundant INS based on triple rotary inertial measurement units

Science.gov (United States)

Chen, Gang; Li, Kui; Wang, Wei; Li, Peng

2016-10-01

Accuracy and reliability are two key performances of inertial navigation system (INS). Rotation modulation (RM) can attenuate the bias of inertial sensors and make it possible for INS to achieve higher navigation accuracy with lower-class sensors. Therefore, the conflict between the accuracy and cost of INS can be eased. Traditional system redundancy and recently researched sensor redundancy are two primary means to improve the reliability of INS. However, how to make the best use of the redundant information from redundant sensors hasn’t been studied adequately, especially in rotational INS. This paper proposed a novel triple rotary unit strapdown inertial navigation system (TRUSINS), which combines RM and sensor redundancy design to enhance the accuracy and reliability of rotational INS. Each rotary unit independently rotates to modulate the errors of two gyros and two accelerometers. Three units can provide double sets of measurements along all three axes of body frame to constitute a couple of INSs which make TRUSINS redundant. Experiments and simulations based on a prototype which is made up of six fiber-optic gyros with drift stability of 0.05° h-1 show that TRUSINS can achieve positioning accuracy of about 0.256 n mile h-1, which is ten times better than that of a normal non-rotational INS with the same level inertial sensors. The theoretical analysis and the experimental results show that due to the advantage of the innovative structure, the designed fault detection and isolation (FDI) strategy can tolerate six sensor faults at most, and is proved to be effective and practical. Therefore, TRUSINS is particularly suitable and highly beneficial for the applications where high accuracy and high reliability is required.

Inertial measurements units for assessment of the pattern of forward bending among blue-collar workers from the DPhacto cohort

DEFF Research Database (Denmark)

Villumsen, Morten; Madeleine, Pascal; Jørgensen, Marie Birk

Background. New developments in electronics have enabled the use of Inertial Measurement Units (IMUs) to record physical activity in a minimally obstructive manner over several days. Individual, physical and psychosocial risk factors are known to play a role in the development of work...... of forward bending was found during leisure compared to work (pgender (pphysical and psychosocial risk factors leading to low...... of the trunk were extracted from all-day IMU recordings, both at work and during leisure time. Exposure variation analysis was applied on forward bending during both work and leisure time.Low-back pain intensity was measured on a 0–10 scale and divided into low and high pain. Individual factors (age, gender...

Concurrent validity and reliability of torso-worn inertial measurement unit for jump power and height estimation.

Science.gov (United States)

Rantalainen, Timo; Gastin, Paul B; Spangler, Rhys; Wundersitz, Daniel

2018-09-01

The purpose of the present study was to evaluate the concurrent validity and test-retest repeatability of torso-worn IMU-derived power and jump height in a counter-movement jump test. Twenty-seven healthy recreationally active males (age, 21.9 [SD 2.0] y, height, 1.76 [0.7] m, mass, 73.7 [10.3] kg) wore an IMU and completed three counter-movement jumps a week apart. A force platform and a 3D motion analysis system were used to concurrently measure the jumps and subsequently derive power and jump height (based on take-off velocity and flight time). The IMU significantly overestimated power (mean difference = 7.3 W/kg; P jump heights exhibited poorer concurrent validity (ICC = 0.72 to 0.78) and repeatability (ICC = 0.68) than flight-time-derived jump heights, which exhibited excellent validity (ICC = 0.93 to 0.96) and reliability (ICC = 0.91). Since jump height and power are closely related, and flight-time-derived jump height exhibits excellent concurrent validity and reliability, flight-time-derived jump height could provide a more desirable measure compared to power when assessing athletic performance in a counter-movement jump with IMUs.

Flight Demonstration Results of an Inertial Measurement Unit and Global Positioning System Translator Telemetry System

National Research Council Canada - National Science Library

David, Bradford

2001-01-01

.... A GPS translator from the Johns Hopkins University Applied Physics Laboratory and a low-cost IMU designed by ARL from commercial off-the-shelf components were combined with a telemetry system, packaged...

Applications of Should Cost to Achieve Cost Reductions

Science.gov (United States)

2014-04-01

CAS . . . . . . . . Control Actuation Section CATM . . . . . . Captive Air Training Missile CATM BIT . . . . . . . . . Captive Air Training Missile...Integrated Fire Control Network IMU . . . . . . . . . . Inertial Measurment Unit IOC . . . . . . .Initial Operational Capability IOT . . . . . . . . . Initial

IceBridge LVIS L0 Raw Ranges

Data.gov (United States)

National Aeronautics and Space Administration — This data set contains raw laser altimeter, Inertial Measurement Unit (IMU), Global Positioning System (GPS), and camera data over Greenland and Antarctica taken...

IceBridge LVIS L0 Raw Ranges

Data.gov (United States)

National Aeronautics and Space Administration — This data set contains raw laser altimeter, Inertial Measurement Unit (IMU), Global Positioning System (GPS), and camera data over Greenland, Antarctica, and Alaska...

Opportunities for measuring wheelchair kinematics in match settings; reliability of a three inertial sensor configuration.

Science.gov (United States)

van der Slikke, R M A; Berger, M A M; Bregman, D J J; Lagerberg, A H; Veeger, H E J

2015-09-18

Knowledge of wheelchair kinematics during a match is prerequisite for performance improvement in wheelchair basketball. Unfortunately, no measurement system providing key kinematic outcomes proved to be reliable in competition. In this study, the reliability of estimated wheelchair kinematics based on a three inertial measurement unit (IMU) configuration was assessed in wheelchair basketball match-like conditions. Twenty participants performed a series of tests reflecting different motion aspects of wheelchair basketball. During the tests wheelchair kinematics were simultaneously measured using IMUs on wheels and frame, and a 24-camera optical motion analysis system serving as gold standard. Results showed only small deviations of the IMU method compared to the gold standard, once a newly developed skid correction algorithm was applied. Calculated Root Mean Square Errors (RMSE) showed good estimates for frame displacement (RMSE≤0.05 m) and speed (RMSE≤0.1m/s), except for three truly vigorous tests. Estimates of frame rotation in the horizontal plane (RMSE0.90), rotational speed (ICC>0.99) and IRC (ICC> 0.90) showed high correlations between IMU data and gold standard. IMU based estimation of wheelchair kinematics provided reliable results, except for brief moments of wheel skidding in truly vigorous tests. The IMU method is believed to enable prospective research in wheelchair basketball match conditions and contribute to individual support of athletes in everyday sports practice. Copyright © 2015 Elsevier Ltd. All rights reserved.

Extended Kalman filter-based methods for pose estimation using visual, inertial and magnetic sensors: comparative analysis and performance evaluation.

Science.gov (United States)

Ligorio, Gabriele; Sabatini, Angelo Maria

2013-02-04

In this paper measurements from a monocular vision system are fused with inertial/magnetic measurements from an Inertial Measurement Unit (IMU) rigidly connected to the camera. Two Extended Kalman filters (EKFs) were developed to estimate the pose of the IMU/camera sensor moving relative to a rigid scene (ego-motion), based on a set of fiducials. The two filters were identical as for the state equation and the measurement equations of the inertial/magnetic sensors. The DLT-based EKF exploited visual estimates of the ego-motion using a variant of the Direct Linear Transformation (DLT) method; the error-driven EKF exploited pseudo-measurements based on the projection errors from measured two-dimensional point features to the corresponding three-dimensional fiducials. The two filters were off-line analyzed in different experimental conditions and compared to a purely IMU-based EKF used for estimating the orientation of the IMU/camera sensor. The DLT-based EKF was more accurate than the error-driven EKF, less robust against loss of visual features, and equivalent in terms of computational complexity. Orientation root mean square errors (RMSEs) of 1° (1.5°), and position RMSEs of 3.5 mm (10 mm) were achieved in our experiments by the DLT-based EKF (error-driven EKF); by contrast, orientation RMSEs of 1.6° were achieved by the purely IMU-based EKF.

Concepção de um pequeno sensor inercial 3D

OpenAIRE

Morgado, Francisco Luís Magno

2009-01-01

Com este trabalho pretende-se desenvolver um IMU (Inertial Measurement Unit), fazendo uso de acelerómetros e giroscópios MEMS (Micro-machined Electro-Mechanical Systems) de baixo custo. Esta tecnologia emergente abre novas portas no mundo dos sistemas de navegação inerciais dada a sua simplicidade mecânica. Este IMU permite transferir as medidas para uma unidade de processamento/armazenamento e, por conseguinte, a sua integração em sistemas de navegação mais complexos que façam uso de m...

SIRU utilization. Volume 1: Theory, development and test evaluation

Science.gov (United States)

Musoff, H.

1974-01-01

The theory, development, and test evaluations of the Strapdown Inertial Reference Unit (SIRU) are discussed. The statistical failure detection and isolation, single position calibration, and self alignment techniques are emphasized. Circuit diagrams of the system components are provided. Mathematical models are developed to show the performance characteristics of the subsystems. Specific areas of the utilization program are identified as: (1) error source propagation characteristics and (2) local level navigation performance demonstrations.

A novel redundant INS based on triple rotary inertial measurement units

International Nuclear Information System (INIS)

Chen, Gang; Li, Kui; Wang, Wei; Li, Peng

2016-01-01

Accuracy and reliability are two key performances of inertial navigation system (INS). Rotation modulation (RM) can attenuate the bias of inertial sensors and make it possible for INS to achieve higher navigation accuracy with lower-class sensors. Therefore, the conflict between the accuracy and cost of INS can be eased. Traditional system redundancy and recently researched sensor redundancy are two primary means to improve the reliability of INS. However, how to make the best use of the redundant information from redundant sensors hasn’t been studied adequately, especially in rotational INS. This paper proposed a novel triple rotary unit strapdown inertial navigation system (TRUSINS), which combines RM and sensor redundancy design to enhance the accuracy and reliability of rotational INS. Each rotary unit independently rotates to modulate the errors of two gyros and two accelerometers. Three units can provide double sets of measurements along all three axes of body frame to constitute a couple of INSs which make TRUSINS redundant. Experiments and simulations based on a prototype which is made up of six fiber-optic gyros with drift stability of 0.05° h −1 show that TRUSINS can achieve positioning accuracy of about 0.256 n mile h −1 , which is ten times better than that of a normal non-rotational INS with the same level inertial sensors. The theoretical analysis and the experimental results show that due to the advantage of the innovative structure, the designed fault detection and isolation (FDI) strategy can tolerate six sensor faults at most, and is proved to be effective and practical. Therefore, TRUSINS is particularly suitable and highly beneficial for the applications where high accuracy and high reliability is required. (paper)

Innovative Fiber-Optic Gyroscopes (FOGs) for High Accuracy Space Applications, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — This project aims to develop a compact, highly innovative Inertial Reference/Measurement Unit (IRU/IMU) that pushes the state-of-the-art in high accuracy performance...

Flight envelope protection system for unmanned aerial vehicles

KAUST Repository

Claudel, Christian G.

2016-04-28

Systems and methods to protect the flight envelope in both manual flight and flight by a commercial autopilot are provided. A system can comprise: an inertial measurement unit (IMU); a computing device in data communication with the IMU; an application executable by the computing device comprising: logic that estimates an angle of attack; a slip angle; and a speed of an unmanned aerial vehicle (UAV) based at least in part on data received from the UAV. A method can comprise estimating, via a computing device, flight data of a UAV based at least in part on data received from an IMU; comparing the estimated flight data with measured flight data; and triggering an error indication in response to a determination that the measured flight data exceeds a predefined deviation of the estimated flight data. The estimated speed can comprise an estimated airspeed, vertical speed and/or ground velocity.

Control of Pan-tilt Mechanism Angle using Position Matrix Method

Directory of Open Access Journals (Sweden)

Hendri Maja Saputra

2013-12-01

Full Text Available Control of a Pan-Tilt Mechanism (PTM angle for the bomb disposal robot Morolipi-V2 using inertial sensor measurement unit, x-IMU, has been done. The PTM has to be able to be actively controlled both manually and automatically in order to correct the orientation of the moving Morolipi-V2 platform. The x-IMU detects the platform orientation and sends the result in order to automatically control the PTM. The orientation is calculated using the quaternion combined with Madwick and Mahony filter methods. The orientation data that consists of angles of roll (α, pitch (β, and yaw (γ from the x-IMU are then being sent to the camera for controlling the PTM motion (pan & tilt angles after calculating the reverse angle using position matrix method. Experiment results using Madwick and Mahony methods show that the x-IMU can be used to find the robot platform orientation. Acceleration data from accelerometer and flux from magnetometer produce noise with standard deviation of 0.015 g and 0.006 G, respectively. Maximum absolute errors caused by Madgwick and Mahony method with respect to Xaxis are 48.45º and 33.91º, respectively. The x-IMU implementation as inertia sensor to control the Pan-Tilt Mechanism shows a good result, which the probability of pan angle tends to be the same with yaw and tilt angle equal to the pitch angle, except a very small angle shift due to the influence of roll angle..

APPLYING 3D AFFINE TRANSFORMATION AND LEAST SQUARES MATCHING FOR AIRBORNE LASER SCANNING STRIPS ADJUSTMENT WITHOUT GNSS/IMU TRAJECTORY DATA

Directory of Open Access Journals (Sweden)

C. Ressl

2012-09-01

Full Text Available In this article we extend our previous work on the topic of ALS strip adjustment without GNSS/IMU trajectory data. Between overlap- ping strip pairs the relative orientation as a 3D affine transformation is estimated by a 3D LSM approach, which uses interpolated 2.5D grid surface models of the strips and the entire strip overlap as one big LSM window. The LSM derived relative orientations of all strip pairs in the block together with their covariance matrices are then used simultaneously as observations in an adjustment following the Gauss-Helmert model. This way the exterior orientation of each strip is computed, which refers to a relative block system. If proper ground control data is given, then an absolute orientation of the block of strips can be computed by a final LSM run. In a small example consisting of 4 strips with ca. 70% overlap the improvement in the relative geometric accuracy is demonstrated by the decreasing óMAD of the height differences from 8.4cm (before to 1.6cm (after the strip adjustment.

NA-241_Quarterly Report_SBLibby - 12.31.2017_v2

Energy Technology Data Exchange (ETDEWEB)

Libby, Stephen B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Physics Dept.

2018-01-22

This is an evaluation of candidate navigation solutions for GPS free inspection tools that can be used in tours of large building interiors. In principle, COTS portable inertial motion unit (IMU) sensors with satisfactory accuracy, SWAP (size, weight, power), low error, and bias drift can provide sufficiently accurate dead reckoning navigation in a large building in the absence of GPS. To explore this assumption, the capabilities of representative IMU navigation sensors to meet these requirements will be evaluated, starting with a market survey, and then carrying out a basic analysis of these sensors using LLNL’s navigation codes.

INS/EKF-based stride length, height and direction intent detection for walking assistance robots.

Science.gov (United States)

Brescianini, Dario; Jung, Jun-Young; Jang, In-Hun; Park, Hyun Sub; Riener, Robert

2011-01-01

We propose an algorithm used to obtain the information on stride length, height difference, and direction based on user's intent during walking. For exoskeleton robots used to assist paraplegic patients' walking, this information is used to generate gait patterns by themselves in on-line. To obtain this information, we attach an inertial measurement unit(IMU) on crutches and apply an extended kalman filter-based error correction method to reduce the phenomena of drift due to bias of the IMU. The proposed method is verifed in real walking scenarios including walking, climbing up-stairs, and changing direction of walking with normal. © 2011 IEEE

IMU-Based Gait Recognition Using Convolutional Neural Networks and Multi-Sensor Fusion

Directory of Open Access Journals (Sweden)

Omid Dehzangi

2017-11-01

identification task. Based on our experimental results, 91% subject identification accuracy was achieved using the best individual IMU and 2DTF-DCNN. We then investigated our proposed early and late sensor fusion approaches, which improved the gait identification accuracy of the system to 93.36% and 97.06%, respectively.

A Map/INS/Wi-Fi Integrated System for Indoor Location-Based Service Applications.

Science.gov (United States)

Yu, Chunyang; Lan, Haiyu; Gu, Fuqiang; Yu, Fei; El-Sheimy, Naser

2017-06-02

In this research, a new Map/INS/Wi-Fi integrated system for indoor location-based service (LBS) applications based on a cascaded Particle/Kalman filter framework structure is proposed. Two-dimension indoor map information, together with measurements from an inertial measurement unit (IMU) and Received Signal Strength Indicator (RSSI) value, are integrated for estimating positioning information. The main challenge of this research is how to make effective use of various measurements that complement each other in order to obtain an accurate, continuous, and low-cost position solution without increasing the computational burden of the system. Therefore, to eliminate the cumulative drift caused by low-cost IMU sensor errors, the ubiquitous Wi-Fi signal and non-holonomic constraints are rationally used to correct the IMU-derived navigation solution through the extended Kalman Filter (EKF). Moreover, the map-aiding method and map-matching method are innovatively combined to constrain the primary Wi-Fi/IMU-derived position through an Auxiliary Value Particle Filter (AVPF). Different sources of information are incorporated through a cascaded structure EKF/AVPF filter algorithm. Indoor tests show that the proposed method can effectively reduce the accumulation of positioning errors of a stand-alone Inertial Navigation System (INS), and provide a stable, continuous and reliable indoor location service.

Sensors and Algorithms for an Unmanned Surf-Zone Robot

Science.gov (United States)

2015-12-01

AXV TESIS - COMPLEMENTARY FILTER TEST % File writen by Oscar Garcia 24/08/15 clear all clc clf imu = fopen(’imucomp2.txt’,’r’); 178...IMU data fusion and filtering using a first order Kalman filter. % AXV TESIS - IMU KALMAN FILTER TEST % File writen by Oscar Garcia 30/08/15...AXV_IMU_EKF.m It performs IMU data fusion and filtering using an extended Kalman filter. % AXV TESIS - IMU EKF TEST % File writen by Oscar Garcia 30/08

From big data to rich data : The key features of athlete wheelchair mobility performance

NARCIS (Netherlands)

van der Slikke, R.M.A.; Berger, MAM; Bregman, DJJ; Veeger, H.E.J.

2016-01-01

Quantitative assessment of an athlete׳s individual wheelchair mobility performance is one prerequisite needed to evaluate game performance, improve wheelchair settings and optimize training routines. Inertial Measurement Unit (IMU) based methods can be used to perform such quantitative assessment,

RECALMIN: The association between management of Spanish National Health Service Internal Medical Units and health outcomes.

Science.gov (United States)

Zapatero-Gaviria, Antonio; Javier Elola-Somoza, Francisco; Casariego-Vales, Emilio; Fernandez-Perez, Cristina; Gomez-Huelgas, Ricardo; Bernal, José Luis; Barba-Martín, Raquel

2017-08-01

To investigate the association between management of Internal Medical Units (IMUs) with outcomes (mortality and length of stay) within the Spanish National Health Service. Data on management were obtained from a descriptive transversal study performed among IMUs of the acute hospitals. Outcome indicators were taken from an administrative database of all hospital discharges from the IMUs. Spanish National Health Service. One hundred and twenty-four acute general hospitals with available data of management and outcomes (401 424 discharges). IMU risk standardized mortality rates were calculated using a multilevel model adjusted by Charlson Index. Risk standardized myocardial infarction and heart failure mortality rates were calculated using specific multilevel models. Length of stay was adjusted by complexity. Greater hospital complexity was associated with longer average length of stays (r: 0.42; P International Society for Quality in Health Care. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Application of Mobile Laser Scanning for Lean and Rapid Highway Maintenance and Construction

Science.gov (United States)

2015-08-28

Mobile Terrestrial Laser Scanning (MTLS) is an emerging technology that combines the use of a laser scanner(s), the Global Navigation Satellite System (GNSS), and an Inertial Measurement Unit (IMU) on a vehicle to collect geo-spatial data. The overal...

Movements Indicate Threat Response Phases in Children at Risk for Anxiety.

Science.gov (United States)

McGinnis, Ellen W; McGinnis, Ryan S; Muzik, Maria; Hruschak, Jessica; Lopez-Duran, Nestor L; Perkins, Noel C; Fitzgerald, Kate; Rosenblum, Katherine L

2017-09-01

Temporal phases of threat response, including potential threat (anxiety), acute threat (startle, fear), and post-threat response modulation, have been identified as the underlying markers of anxiety disorders. Objective measures of response during these phases may help identify children at risk for anxiety; however, the complexity of current assessment techniques prevent their adoption in many research and clinical contexts. We propose an alternative technology, an inertial measurement unit (IMU), that enables noninvasive measurement of the movements associated with threat response, and test its ability to detect threat response phases in young children at a heightened risk for developing anxiety. We quantified the motion of 18 children (3-7 years old) during an anxiety-/fear-provoking behavioral task using an IMU. Specifically, measurements from a single IMU secured to the child's waist were used to extract root-mean-square acceleration and angular velocity in the horizontal and vertical directions, and tilt and yaw range of motion during each threat response phase. IMU measurements detected expected differences in child motion by threat phase. Additionally, potential threat motion was positively correlated to familial anxiety risk, startle range of motion was positively correlated with child internalizing symptoms, and response modulation motion was negatively correlated to familial anxiety risk. Results suggest differential theory-driven threat response phases and support previous literature connecting maternal child risk to anxiety with behavioral measures using more feasible objective methods. This is the first study demonstrating the utility of an IMU for characterizing the motion of young children to mark the phases of threat response modulation. The technique provides a novel and objective measure of threat response for mental health researchers.

Patient-reported outcome measures versus inertial performance-based outcome measures: A prospective study in patients undergoing primary total knee arthroplasty.

Science.gov (United States)

Bolink, S A A N; Grimm, B; Heyligers, I C

2015-12-01

Outcome assessment of total knee arthroplasty (TKA) by subjective patient reported outcome measures (PROMs) may not fully capture the functional (dis-)abilities of relevance. Objective performance-based outcome measures could provide distinct information. An ambulant inertial measurement unit (IMU) allows kinematic assessment of physical performance and could potentially be used for routine follow-up. To investigate the responsiveness of IMU measures in patients following TKA and compare outcomes with conventional PROMs. Patients with end stage knee OA (n=20, m/f=7/13; age=67.4 standard deviation 7.7 years) were measured preoperatively and one year postoperatively. IMU measures were derived during gait, sit-stand transfers and block step-up transfers. PROMs were assessed by using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Knee Society Score (KSS). Responsiveness was calculated by the effect size, correlations were calculated with Spearman's rho correlation coefficient. One year after TKA, patients performed significantly better at gait, sit-to-stand transfers and block step-up transfers. Measures of time and kinematic IMU measures demonstrated significant improvements postoperatively for each performance-based test. The largest improvement was found in block step-up transfers (effect size=0.56-1.20). WOMAC function score and KSS function score demonstrated moderate correlations (Spearman's rho=0.45-0.74) with some of the physical performance-based measures pre- and postoperatively. To characterize the changes in physical function after TKA, PROMs could be supplemented by performance-based measures, assessing function during different activities and allowing kinematic characterization with an ambulant IMU. Copyright © 2015 Elsevier B.V. All rights reserved.

Mobile App to Streamline the Development of Wearable Sensor-Based Exercise Biofeedback Systems: System Development and Evaluation.

Science.gov (United States)

O'Reilly, Martin; Duffin, Joe; Ward, Tomas; Caulfield, Brian

2017-08-21

Biofeedback systems that use inertial measurement units (IMUs) have been shown recently to have the ability to objectively assess exercise technique. However, there are a number of challenges in developing such systems; vast amounts of IMU exercise datasets must be collected and manually labeled for each exercise variation, and naturally occurring technique deviations may not be well detected. One method of combatting these issues is through the development of personalized exercise technique classifiers. We aimed to create a tablet app for physiotherapists and personal trainers that would automate the development of personalized multiple and single IMU-based exercise biofeedback systems for their clients. We also sought to complete a preliminary investigation of the accuracy of such individualized systems in a real-world evaluation. A tablet app was developed that automates the key steps in exercise technique classifier creation through synchronizing video and IMU data collection, automatic signal processing, data segmentation, data labeling of segmented videos by an exercise professional, automatic feature computation, and classifier creation. Using a personalized single IMU-based classification system, 15 volunteers (12 males, 3 females, age: 23.8 [standard deviation, SD 1.8] years, height: 1.79 [SD 0.07] m, body mass: 78.4 [SD 9.6] kg) then completed 4 lower limb compound exercises. The real-world accuracy of the systems was evaluated. The tablet app successfully automated the process of creating individualized exercise biofeedback systems. The personalized systems achieved 89.50% (1074/1200) accuracy, with 90.00% (540/600) sensitivity and 89.00% (534/600) specificity for assessing aberrant and acceptable technique with a single IMU positioned on the left thigh. A tablet app was developed that automates the process required to create a personalized exercise technique classification system. This tool can be applied to any cyclical, repetitive exercise. The

Giving Inertial Sensor Data Context for Communication in Applied Settings: An Example of Visual Exploration in Football

Directory of Open Access Journals (Sweden)

Thomas B. McGuckian

2018-02-01

Full Text Available For an athlete to make an appropriate decision and successfully perform a skill, they need to perceive opportunities for action by visually exploring their environment. The head movements that support visual exploration can easily and accurately be recorded using Micro-Electro-Mechanical Systems (MEMS Inertial Measurement Units (IMU in research and applied settings. However, for IMU technology to be effective in applied settings, practitioners need to be able to communicate data to coaches and players. This paper presents methods of visualising and communicating exploratory head movement data, with the aim of giving a better understanding of (a individual differences in exploratory action, and (b how IMUs can be used in applied settings to assess and monitor visual exploratory action.

Map matching and heuristic elimination of gyro drift for personal navigation systems in GPS-denied conditions

International Nuclear Information System (INIS)

Aggarwal, Priyanka; Thomas, David; Ojeda, Lauro; Borenstein, Johann

2011-01-01

This paper introduces a method for the substantial reduction of heading errors in inertial navigation systems used under GPS-denied conditions. Presumably, the method is applicable for both vehicle-based and personal navigation systems, but experiments were performed only with a personal navigation system called 'personal dead reckoning' (PDR). In order to work under GPS-denied conditions, the PDR system uses a foot-mounted inertial measurement unit (IMU). However, gyro drift in this IMU can cause large heading errors after just a few minutes of walking. To reduce these errors, the map-matched heuristic drift elimination (MAPHDE) method was developed, which estimates gyro drift errors by comparing IMU-derived heading to the direction of the nearest street segment in a database of street maps. A heuristic component in this method provides tolerance to short deviations from walking along the street, such as when crossing streets or intersections. MAPHDE keeps heading errors almost at zero, and, as a result, position errors are dramatically reduced. In this paper, MAPHDE was used in a variety of outdoor walks, without any use of GPS. This paper explains the MAPHDE method in detail and presents experimental results

Hospital organization and importance of an interventional radiology inpatient admitting service: Italian single-center 3-year experience.

Science.gov (United States)

Simonetti, Giovanni; Bollero, Enrico; Ciarrapico, Anna Micaela; Gandini, Roberto; Konda, Daniel; Bartolucci, Alberto; Di Primio, Massimiliano; Mammucari, Matteo; Chiocchi, Marcello; D'Alba, Fabrizio; Masala, Salvatore

2009-03-01

In June 2005 a Complex Operating Unit of Interventional Radiology (COUIR), consisting of an outpatient visit service, an inpatient admitting service with four beds, and a day-hospital service with four beds was installed at our department. Between June 2005 and May 2008, 1772 and 861 well-screened elective patients were admitted to the inpatient ward of the COUIR and to the Internal Medicine Unit (IMU) or Surgery Unit (SU) of our hospital, respectively, and treated with IR procedures. For elective patients admitted to the COUIR's inpatient ward, hospital stays were significantly shorter and differences between reimbursements and costs were significantly higher for almost all IR procedures compared to those for patients admitted to the IMU and SU (Student's t-test for unpaired data, p money and obtain positive margins (differences between reimbursements and costs). During 3 years of activity, the inpatient admitting service of our COUIR yielded a positive difference between reimbursements and effective costs of 1,009,095.35 euros. The creation of an inpatient IR service and the admission of well-screened elective patients allowed short hospitalization times, reduction of waiting lists, and a positive economic outcome.

Symposium Gyro Technology 1984; Proceedings of the Symposium, Universitaet Stuttgart, West Germany, September 11, 12, 1984

Science.gov (United States)

Sorg, H.

Among the topics discussed are: drift and scale factor tests on the SEL fiber gyro; integrated optical rate sensor development; and the beam geometry of a ring laser gyro in relation to its performance. Consideration is also given to: a fast filtering technique for measuring random walk in a laser gyro; vibratory gyroscopic sensors; a redundant strapdown reference for advanced aircraft flight control systems; and a low-cost piezoelectric rate/acceleration sensor. Additional topics include: an inertial guidance system for a Low-Earth-Orbit (LEO) vehicle; and signal disturbance effects in a strapdown northfinder.

Detection of chaotic dynamics in human gait signals from mobile devices

Science.gov (United States)

DelMarco, Stephen; Deng, Yunbin

2017-05-01

The ubiquity of mobile devices offers the opportunity to exploit device-generated signal data for biometric identification, health monitoring, and activity recognition. In particular, mobile devices contain an Inertial Measurement Unit (IMU) that produces acceleration and rotational rate information from the IMU accelerometers and gyros. These signals reflect motion properties of the human carrier. It is well-known that the complexity of bio-dynamical systems gives rise to chaotic dynamics. Knowledge of chaotic properties of these systems has shown utility, for example, in detecting abnormal medical conditions and neurological disorders. Chaotic dynamics has been found, in the lab, in bio-dynamical systems data such as electrocardiogram (heart), electroencephalogram (brain), and gait data. In this paper, we investigate the following question: can we detect chaotic dynamics in human gait as measured by IMU acceleration and gyro data from mobile phones? To detect chaotic dynamics, we perform recurrence analysis on real gyro and accelerometer signal data obtained from mobile devices. We apply the delay coordinate embedding approach from Takens' theorem to reconstruct the phase space trajectory of the multi-dimensional gait dynamical system. We use mutual information properties of the signal to estimate the appropriate delay value, and the false nearest neighbor approach to determine the phase space embedding dimension. We use a correlation dimension-based approach together with estimation of the largest Lyapunov exponent to make the chaotic dynamics detection decision. We investigate the ability to detect chaotic dynamics for the different one-dimensional IMU signals, across human subject and walking modes, and as a function of different phone locations on the human carrier.

Non-verbal communication through sensor fusion

Science.gov (United States)

Tairych, Andreas; Xu, Daniel; O'Brien, Benjamin M.; Anderson, Iain A.

2016-04-01

When we communicate face to face, we subconsciously engage our whole body to convey our message. In telecommunication, e.g. during phone calls, this powerful information channel cannot be used. Capturing nonverbal information from body motion and transmitting it to the receiver parallel to speech would make these conversations feel much more natural. This requires a sensing device that is capable of capturing different types of movements, such as the flexion and extension of joints, and the rotation of limbs. In a first embodiment, we developed a sensing glove that is used to control a computer game. Capacitive dielectric elastomer (DE) sensors measure finger positions, and an inertial measurement unit (IMU) detects hand roll. These two sensor technologies complement each other, with the IMU allowing the player to move an avatar through a three-dimensional maze, and the DE sensors detecting finger flexion to fire weapons or open doors. After demonstrating the potential of sensor fusion in human-computer interaction, we take this concept to the next level and apply it in nonverbal communication between humans. The current fingerspelling glove prototype uses capacitive DE sensors to detect finger gestures performed by the sending person. These gestures are mapped to corresponding messages and transmitted wirelessly to another person. A concept for integrating an IMU into this system is presented. The fusion of the DE sensor and the IMU combines the strengths of both sensor types, and therefore enables very comprehensive body motion sensing, which makes a large repertoire of gestures available to nonverbal communication over distances.

Data analysis of inertial sensor for train positioning detection system

Energy Technology Data Exchange (ETDEWEB)

Kim, Seong Jin; Park, Sung Soo; Lee, Jae Ho; Kang, Dong Hoon [Korea Railroad Research Institute, Uiwang (Korea, Republic of)

2015-02-15

Train positioning detection information is fundamental for high-speed railroad inspection, making it possible to simultaneously determine the status and evaluate the integrity of railroad equipment. This paper presents the results of measurements and an analysis of an inertial measurement unit (IMU) used as a positioning detection sensors. Acceleration and angular rate measurements from the IMU were analyzed in the amplitude and frequency domains, with a discussion on vibration and train motions. Using these results and GPS information, the positioning detection of a Korean tilting train express was performed from Naju station to Illo station on the Honam-line. The results of a synchronized analysis of sensor measurements and train motion can help in the design of a train location detection system and improve the positioning detection performance.

VRACK: measuring pedal kinematics during stationary bike cycling.

Science.gov (United States)

Farjadian, Amir B; Kong, Qingchao; Gade, Venkata K; Deutsch, Judith E; Mavroidis, Constantinos

2013-06-01

Ankle impairment and lower limb asymmetries in strength and coordination are common symptoms for individuals with selected musculoskeletal and neurological impairments. The virtual reality augmented cycling kit (VRACK) was designed as a compact mechatronics system for lower limb and mobility rehabilitation. The system measures interaction forces and cardiac activity during cycling in a virtual environment. The kinematics measurement was added to the system. Due to the constrained problem definition, the combination of inertial measurement unit (IMU) and Kalman filtering was recruited to compute the optimal pedal angular displacement during dynamic cycling exercise. Using a novel benchmarking method the accuracy of IMU-based kinematics measurement was evaluated. Relatively accurate angular measurements were achieved. The enhanced VRACK system can serve as a rehabilitation device to monitor biomechanical and physiological variables during cycling on a stationary bike.

Pipeline mapping and strain assessment using ILI (In-line Inspection) tolls

Energy Technology Data Exchange (ETDEWEB)

Purvis, Brian [GE PII Pipeline Solutions, Rio de Janeiro, RJ (Brazil); Huewener, Thomas [E.ON Ruhrgas AG, Essen (Germany)

2009-07-01

GE PII IMU Mapping inspection system measures pipeline location coordinates (x, y, z) and provides data for determining pipeline curvature and consequential pipeline bending strain. The changes in strain can be used in the application of structural analyses and integrity evaluation of pipeline systems. This paper reviews the Inertia Measuring Unit (IMU) system and field investigation works performed on a high-pressure gas pipeline for E.ON Ruhrgas AG. The Inertial Measuring Unit of the pipeline inspection tool provides continuous measurement of the pipeline centreline coordinates. More than one inspection run was performed which allowed a more accurate strain comparison to be made. Repeatability is important to establish the reasons for increasing strain values detected at specific pipeline sections through in-line inspection surveys conducted in regular intervals over many years. Moreover, the flexibility resulting from a combination of different sensor technologies, makes it possible to provide a more complete picture of the overall situation. This paper reviews the work involved in detecting, locating and determining the magnitude and type of strain corresponding to the pipeline movement in field. (author)

A Study on the Storage Reliability of LSINS Based on Step-stress Accelerated Life Test

Directory of Open Access Journals (Sweden)

Teng Fei

2015-01-01

Full Text Available Based on the step-stress accelerated life test and the laser strap-down inertial navigation system, this paper studies the accelerated life model and the test method, provides the likelihood function, the likelihood equation and the two-order derivative when the stress level is k, evaluates the effectiveness of the method with the simulation test model established by MATLAB, applies the research findings in the storage reliability study of the XX laser strap-down inertial navigation system, and puts forward an effective evaluation method of the storage life of the inertial navigation system.

SLAM-Aided Stem Mapping for Forest Inventory with Small-Footprint Mobile LiDAR

Directory of Open Access Journals (Sweden)

Jian Tang

2015-12-01

Full Text Available Accurately retrieving tree stem location distributions is a basic requirement for biomass estimation of forest inventory. Combining Inertial Measurement Units (IMU with Global Navigation Satellite Systems (GNSS is a commonly used positioning strategy in most Mobile Laser Scanning (MLS systems for accurate forest mapping. Coupled with a tactical or consumer grade IMU, GNSS offers a satisfactory solution in open forest environments, for which positioning accuracy better than one decimeter can be achieved. However, for such MLS systems, positioning in a mature and dense forest is still a challenging task because of the loss of GNSS signals attenuated by thick canopy. Most often laser scanning sensors in MLS systems are used for mapping and modelling rather than positioning. In this paper, we investigate a Simultaneous Localization and Mapping (SLAM-aided positioning solution with point clouds collected by a small-footprint LiDAR. Based on the field test data, we evaluate the potential of SLAM positioning and mapping in forest inventories. The results show that the positioning accuracy in the selected test field is improved by 38% compared to that of a traditional tactical grade IMU + GNSS positioning system in a mature forest environment and, as a result, we are able to produce a unambiguous tree distribution map.

Determine the Foot Strike Pattern Using Inertial Sensors

Directory of Open Access Journals (Sweden)

Tzyy-Yuang Shiang

2016-01-01

Full Text Available From biomechanical point of view, strike pattern plays an important role in preventing potential injury risk in running. Traditionally, strike pattern determination was conducted by using 3D motion analysis system with cameras. However, the procedure is costly and not convenient. With the rapid development of technology, sensors have been applied in sport science field lately. Therefore, this study was designed to determine the algorithm that can identify landing strategies with a wearable sensor. Six healthy male participants were recruited to perform heel and forefoot strike strategies at 7, 10, and 13 km/h speeds. The kinematic data were collected by Vicon 3D motion analysis system and 2 inertial measurement units (IMU attached on the dorsal side of both shoes. The data of each foot strike were gathered for pitch angle and strike index analysis. Comparing the strike index from IMU with the pitch angle from Vicon system, our results showed that both signals exhibited highly correlated changes between different strike patterns in the sagittal plane (r=0.98. Based on the findings, the IMU sensors showed potential capabilities and could be extended beyond the context of sport science to other fields, including clinical applications.

Loose Coupling of Wearable-Based INSs with Automatic Heading Evaluation

Directory of Open Access Journals (Sweden)

Dina Bousdar Ahmed

2017-11-01

Full Text Available Position tracking of pedestrians by means of inertial sensors is a highly explored field of research. In fact, there are already many approaches to implement inertial navigation systems (INSs. However, most of them use a single inertial measurement unit (IMU attached to the pedestrian’s body. Since wearable-devices will be given items in the future, this work explores the implementation of an INS using two wearable-based IMUs. A loosely coupled approach is proposed to combine the outputs of wearable-based INSs. The latter are based on a pocket-mounted IMU and a foot-mounted IMU. The loosely coupled fusion combines the output of the two INSs not only when these outputs are least erroneous, but also automatically favoring the best output. This approach is named smart update. The main challenge is determining the quality of the heading estimation of each INS, which changes every time. In order to address this, a novel concept to determine the quality of the heading estimation is presented. This concept is subject to a patent application. The results show that the position error rate of the loosely coupled fusion is 10 cm/s better than either the foot INS’s or pocket INS’s error rate in 95% of the cases.

Loose Coupling of Wearable-Based INSs with Automatic Heading Evaluation.

Science.gov (United States)

Bousdar Ahmed, Dina; Munoz Diaz, Estefania

2017-11-03

Position tracking of pedestrians by means of inertial sensors is a highly explored field of research. In fact, there are already many approaches to implement inertial navigation systems (INSs). However, most of them use a single inertial measurement unit (IMU) attached to the pedestrian's body. Since wearable-devices will be given items in the future, this work explores the implementation of an INS using two wearable-based IMUs. A loosely coupled approach is proposed to combine the outputs of wearable-based INSs. The latter are based on a pocket-mounted IMU and a foot-mounted IMU. The loosely coupled fusion combines the output of the two INSs not only when these outputs are least erroneous, but also automatically favoring the best output. This approach is named smart update. The main challenge is determining the quality of the heading estimation of each INS, which changes every time. In order to address this, a novel concept to determine the quality of the heading estimation is presented. This concept is subject to a patent application. The results show that the position error rate of the loosely coupled fusion is 10 cm/s better than either the foot INS's or pocket INS's error rate in 95% of the cases.

Testing the assumption of normality in body sway area calculations during unipedal stance tests with an inertial sensor.

Science.gov (United States)

Kyoung Jae Kim; Lucarevic, Jennifer; Bennett, Christopher; Gaunaurd, Ignacio; Gailey, Robert; Agrawal, Vibhor

2016-08-01

The quantification of postural sway during the unipedal stance test is one of the essentials of posturography. A shift of center of pressure (CoP) is an indirect measure of postural sway and also a measure of a person's ability to maintain balance. A widely used method in laboratory settings to calculate the sway of body center of mass (CoM) is through an ellipse that encloses 95% of CoP trajectory. The 95% ellipse can be computed under the assumption that the spatial distribution of the CoP points recorded from force platforms is normal. However, to date, this assumption of normality has not been demonstrated for sway measurements recorded from a sacral inertial measurement unit (IMU). This work provides evidence for non-normality of sway trajectories calculated at a sacral IMU with injured subjects as well as healthy subjects.

Systems Engineering Approach to Develop Guidance, Navigation and Control Algorithms for Unmanned Ground Vehicle

Science.gov (United States)

2016-09-01

Global Positioning System HNA hybrid navigation algorithm HRI human-robot interface IED Improvised Explosive Device IMU inertial measurement unit...Potential Field Method R&D research and development RDT&E Research, development, test and evaluation RF radiofrequency RGB red, green and blue ROE...were radiofrequency (RF) controlled and pneumatically actuated upon receiving the wireless commands from the radio operator. The pairing of such an

Inertially Stabilized Platforms for Precision Pointing Applications to Directed-Energy Weapons and Space-Based Lasers (Preprint)

National Research Council Canada - National Science Library

Negro, J; Griffin, S

2006-01-01

.... This article addresses directed-energy-weapon (DEW) precision pointing requirements and implementation alternatives in the context of strapdown and stable-platform inertial-reference technologies...

Single Sensor Gait Analysis to Detect Diabetic Peripheral Neuropathy: A Proof of Principle Study

Directory of Open Access Journals (Sweden)

Patrick Esser

2018-01-01

Full Text Available This study explored the potential utility of gait analysis using a single sensor unit (inertial measurement unit [IMU] as a simple tool to detect peripheral neuropathy in people with diabetes. Seventeen people (14 men aged 63±9 years (mean±SD with diabetic peripheral neuropathy performed a 10-m walk test instrumented with an IMU on the lower back. Compared to a reference healthy control data set (matched by gender, age, and body mass index both spatiotemporal and gait control variables were different between groups, with walking speed, step time, and SDa (gait control parameter demonstrating good discriminatory power (receiver operating characteristic area under the curve >0.8. These results provide a proof of principle of this relatively simple approach which, when applied in clinical practice, can detect a signal from those with known diabetes peripheral neuropathy. The technology has the potential to be used both routinely in the clinic and for tele-health applications. Further research should focus on investigating its efficacy as an early indicator of or effectiveness of the management of peripheral neuropathy. This could support the development of interventions to prevent complications such as foot ulceration or Charcot's foot.

Integrating ILI data with publicly available mapping solutions

Energy Technology Data Exchange (ETDEWEB)

Coleman, Grant A.; Miller, Scott J. [BJ Pipeline Inspection Services, Calgary, AB (Canada)], email: gcoleman@bjservices.ca, email: smiller@bjservices.ca

2010-07-01

With the improvement of the technology, in line inspection tools now incorporate accurate Inertial Mapping Units (IMU) which provide spatial coordinates for the features comprised within a pipeline. Geographic information systems (GIS) can be used to display the data, however some companies do not have such systems and novices cannot navigate easily within the application. The aim of this paper is to present the use of universally available packages to display GIS style data. Case studies are presented in which Google Earth imagery is used to display IMU data. This study showed that universally available packages such as Google Earth do not match the accuracy and functionality of GIS systems but they can be a convenient and easy to use way to display data in a portable format. Organizations that do not have a GIS system could thus benefit from the use of those packages.

Strap-Down Inertial Systems

Science.gov (United States)

1978-05-01

variant, and position fixes can be obtained from line-of-sight. otr-horizon, or correlator type (Terrain contour, radiometfic) systgm. ABIA R.D.V...I W eond, the sensor frort" part of the si~tltfitc esrvmant. ABIA author. 77/00100 77A407,0 THE DYNAMICALLY TUNED GYROSkWE A SENSOR FOR LOW COST

In vitro cytotoxicity of chemical preservatives on human fibroblast cells

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Daniel Gonsales Spindola

2018-05-01

Full Text Available ABSTRACT Preservatives are widely used substances that are commonly added to various cosmetic and pharmaceutical products to prevent or inhibit microbial growth. In this study, we compared the in vitro cytotoxicity of different types of currently used preservatives, including methylparaben, imidazolidinyl urea (IMU, and sodium benzoate, using the human newborn fibroblast cell line CCD1072Sk. Of the tested preservatives, only IMU induced a reduction in cell viability, as shown using the MTT assay and propidium iodide staining (IMU>methylparaben>sodium benzoate. IMU was shown to promote homeostatic alterations potentially related to the initiation of programed cell death, such as decreased mitochondrial membrane potential and caspase-3 activation, in the treated cells. Methylparaben and sodium benzoate were shown to have a very low cytotoxic activity. Taken together, our results suggest that IMU induces programed cell death in human fibroblasts by a canonical intrinsic pathway via mitochondrial perturbation and subsequent release of proapoptotic factors.

The inertial attitude augmentation for ambiguity resolution in SF/SE-GNSS attitude determination.

Science.gov (United States)

Zhu, Jiancheng; Hu, Xiaoping; Zhang, Jingyu; Li, Tao; Wang, Jinling; Wu, Meiping

2014-06-26

The Unaided Single Frequency/Single Epoch Global Navigation Satellite System (SF/SE GNSS) model is the most challenging scenario for ambiguity resolution in the GNSS attitude determination application. To improve the performance of SF/SE-GNSS ambiguity resolution without excessive cost, the Micro-Electro-Mechanical System Inertial Measurement Unit (MEMS-IMU) is a proper choice for the auxiliary sensor that carries out the inertial attitude augmentation. Firstly, based on the SF/SE-GNSS compass model, the Inertial Derived Baseline Vector (IDBV) is defined to connect the MEMS-IMU attitude measurement with the SF/SE-GNSS ambiguity search space, and the mechanism of inertial attitude augmentation is revealed from the perspective of geometry. Then, through the quantitative description of model strength by Ambiguity Dilution of Precision (ADOP), two ADOPs are specified for the unaided SF/SE-GNSS compass model and its inertial attitude augmentation counterparts, respectively, and a sufficient condition is proposed for augmenting the SF/SE-GNSS model strength with inertial attitude measurement. Finally, in the framework of an integer aperture estimator with fixed failure rate, the performance of SF/SE-GNSS ambiguity resolution with inertial attitude augmentation is analyzed when the model strength is varying from strong to weak. The simulation results show that, in the SF/SE-GNSS attitude determination application, MEMS-IMU can satisfy the requirements of ambiguity resolution with inertial attitude augmentation.

The Inertial Attitude Augmentation for Ambiguity Resolution in SF/SE-GNSS Attitude Determination

Science.gov (United States)

Zhu, Jiancheng; Hu, Xiaoping; Zhang, Jingyu; Li, Tao; Wang, Jinling; Wu, Meiping

2014-01-01

The Unaided Single Frequency/Single Epoch Global Navigation Satellite System (SF/SE GNSS) model is the most challenging scenario for ambiguity resolution in the GNSS attitude determination application. To improve the performance of SF/SE-GNSS ambiguity resolution without excessive cost, the Micro-Electro-Mechanical System Inertial Measurement Unit (MEMS-IMU) is a proper choice for the auxiliary sensor that carries out the inertial attitude augmentation. Firstly, based on the SF/SE-GNSS compass model, the Inertial Derived Baseline Vector (IDBV) is defined to connect the MEMS-IMU attitude measurement with the SF/SE-GNSS ambiguity search space, and the mechanism of inertial attitude augmentation is revealed from the perspective of geometry. Then, through the quantitative description of model strength by Ambiguity Dilution of Precision (ADOP), two ADOPs are specified for the unaided SF/SE-GNSS compass model and its inertial attitude augmentation counterparts, respectively, and a sufficient condition is proposed for augmenting the SF/SE-GNSS model strength with inertial attitude measurement. Finally, in the framework of an integer aperture estimator with fixed failure rate, the performance of SF/SE-GNSS ambiguity resolution with inertial attitude augmentation is analyzed when the model strength is varying from strong to weak. The simulation results show that, in the SF/SE-GNSS attitude determination application, MEMS-IMU can satisfy the requirements of ambiguity resolution with inertial attitude augmentation. PMID:24971472

Graph SLAM correction for single scanner MLS forest data under boreal forest canopy

Science.gov (United States)

Kukko, Antero; Kaijaluoto, Risto; Kaartinen, Harri; Lehtola, Ville V.; Jaakkola, Anttoni; Hyyppä, Juha

2017-10-01

Mobile laser scanning (MLS) provides kinematic means to collect three dimensional data from surroundings for various mapping and environmental analysis purposes. Vehicle based MLS has been used for road and urban asset surveys for about a decade. The equipment to derive the trajectory information for the point cloud generation from the laser data is almost without exception based on GNSS-IMU (Global Navigation Satellite System - Inertial Measurement Unit) technique. That is because of the GNSS ability to maintain global accuracy, and IMU to produce the attitude information needed to orientate the laser scanning and imaging sensor data. However, there are known challenges in maintaining accurate positioning when GNSS signal is weak or even absent over long periods of time. The duration of the signal loss affects the severity of degradation of the positioning solution depending on the quality/performance level of the IMU in use. The situation could be improved to a certain extent with higher performance IMUs, but increasing system expenses make such approach unsustainable in general. Another way to tackle the problem is to attach additional sensors to the system to overcome the degrading position accuracy: such that observe features from the environment to solve for short term system movements accurately enough to prevent the IMU solution to drift. This results in more complex system integration with need for more calibration and synchronization of multiple sensors into an operational approach. In this paper we study operation of an ATV (All -terrain vehicle) mounted, GNSS-IMU based single scanner MLS system in boreal forest conditions. The data generated by RoamerR2 system is targeted for generating 3D terrain and tree maps for optimizing harvester operations and forest inventory purposes at individual tree level. We investigate a process-flow and propose a graph optimization based method which uses data from a single scanner MLS for correcting the post

Effects of sensitive electrical stimulation based cueing in Parkinson's disease: a preliminary study

Directory of Open Access Journals (Sweden)

Benoît Sijobert

2016-06-01

Full Text Available This study aims to investigate the effect of a sensitive cueing on Freezing of Gait (FOG and gait disorders in subjects suffering from Parkinson’s disease (PD. 13 participants with Parkinson’s disease were equipped with an electrical stimulator and a foot mounted inertial measurement unit (IMU. An IMU based algorithm triggered in real time an electrical stimulus applied on the arch of foot at heel off detection. Starting from standing, subjects were asked to walk at their preferred speed on a path comprising 5m straight, u-turn and walk around tasks. Cueing globally decreased the time to achieve the different tasks in all the subjects. In “freezer” subjects, the time to complete the entire path was reduced by 19%. FOG events occurrence was lowered by 12% compared to baseline before and after cueing. This preliminary work showed a positive global effect of an electrical stimulation based cueing on gait and FOG in PD.

Effects of Target Positioning Error on Motion Compensation for Airborne Interferometric SAR

Directory of Open Access Journals (Sweden)

Li Yin-wei

2013-12-01

Full Text Available The measurement inaccuracies of Inertial Measurement Unit/Global Positioning System (IMU/GPS as well as the positioning error of the target may contribute to the residual uncompensated motion errors in the MOtion COmpensation (MOCO approach based on the measurement of IMU/GPS. Aiming at the effects of target positioning error on MOCO for airborne interferometric SAR, the paper firstly deduces a mathematical model of residual motion error bring out by target positioning error under the condition of squint. And the paper analyzes the effects on the residual motion error caused by system sampling delay error, the Doppler center frequency error and reference DEM error which result in target positioning error based on the model. Then, the paper discusses the effects of the reference DEM error on the interferometric SAR image quality, the interferometric phase and the coherent coefficient. The research provides theoretical bases for the MOCO precision in signal processing of airborne high precision SAR and airborne repeat-pass interferometric SAR.

Quality Control Methodologies for Advanced EMI Sensor Data Acquisition and Anomaly Classification - Former Southwestern Proving Ground, Arkansas

Science.gov (United States)

2015-07-01

30 LIST OF APPENDICES Appendix A Points of Contact vii 10/2/2015 LIST OF ACRONYMS % percent µT micro Tesla cm...three orthogonal 1-square meter (m²) transmit coils and seven 10-centimeter (cm), three-component, orthogonal receiver coils (Figure 2-1). The system...navigation. The rover head was mounted directly over the center of the MetalMapper transmit coil . An inertial measurement unit (IMU) was installed

Motion measurement for synthetic aperture radar

Energy Technology Data Exchange (ETDEWEB)

Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-01-01

Synthetic Aperture Radar (SAR) measures radar soundings from a set of locations typically along the flight path of a radar platform vehicle. Optimal focusing requires precise knowledge of the sounding source locations in 3-D space with respect to the target scene. Even data driven focusing techniques (i.e. autofocus) requires some degree of initial fidelity in the measurements of the motion of the radar. These requirements may be quite stringent especially for fine resolution, long ranges, and low velocities. The principal instrument for measuring motion is typically an Inertial Measurement Unit (IMU), but these instruments have inherent limi ted precision and accuracy. The question is %22How good does an IMU need to be for a SAR across its performance space?%22 This report analytically relates IMU specifications to parametric requirements for SAR. - 4 - Acknowledgements Th e preparation of this report is the result of a n unfunded research and development activity . Although this report is an independent effort, it draws heavily from limited - release documentation generated under a CRADA with General Atomics - Aeronautical System, Inc. (GA - ASI), and under the Joint DoD/DOE Munitions Program Memorandum of Understanding. Sandia National Laboratories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of En ergy's National Nuclear Security Administration under contract AC04-94AL85000.

APPROACH FOR IMPROVING THE INTEGRATED SENSOR ORIENTATION

Directory of Open Access Journals (Sweden)

E. Mitishita

2016-06-01

Full Text Available The direct determination of exterior orientation parameters (EOP of aerial images via integration of the Inertial Measurement Unit (IMU and GPS is often used in photogrammetric mapping nowadays. The accuracies of the EOP depend on the accurate parameters related to sensors mounting when the job is performed (offsets of the IMU relative to the projection centre and the angles of boresigth misalignment between the IMU and the photogrammetric coordinate system. In principle, when the EOP values do not achieve the required accuracies for the photogrammetric application, the approach, known as Integrated Sensor Orientation (ISO, is used to refine the direct EOP. ISO approach requires accurate Interior Orientation Parameters (IOP and standard deviation of the EOP under flight condition. This paper investigates the feasibility of use the in situ camera calibration to obtain these requirements. The camera calibration uses a small sub block of images, extracted from the entire block. A digital Vexcel UltraCam XP camera connected to APPLANIX POS AVTM system was used to get two small blocks of images that were use in this study. The blocks have different flight heights and opposite flight directions. The proposed methodology improved significantly the vertical and horizontal accuracies of the 3D point intersection. Using a minimum set of control points, the horizontal and vertical accuracies achieved nearly one image pixel of resolution on the ground (GSD. The experimental results are shown and discussed.

Single Sensor Gait Analysis to Detect Diabetic Peripheral Neuropathy: A Proof of Principle Study.

Science.gov (United States)

Esser, Patrick; Collett, Johnny; Maynard, Kevin; Steins, Dax; Hillier, Angela; Buckingham, Jodie; Tan, Garry D; King, Laurie; Dawes, Helen

2018-02-01

This study explored the potential utility of gait analysis using a single sensor unit (inertial measurement unit [IMU]) as a simple tool to detect peripheral neuropathy in people with diabetes. Seventeen people (14 men) aged 63±9 years (mean±SD) with diabetic peripheral neuropathy performed a 10-m walk test instrumented with an IMU on the lower back. Compared to a reference healthy control data set (matched by gender, age, and body mass index) both spatiotemporal and gait control variables were different between groups, with walking speed, step time, and SDa (gait control parameter) demonstrating good discriminatory power (receiver operating characteristic area under the curve >0.8). These results provide a proof of principle of this relatively simple approach which, when applied in clinical practice, can detect a signal from those with known diabetes peripheral neuropathy. The technology has the potential to be used both routinely in the clinic and for tele-health applications. Further research should focus on investigating its efficacy as an early indicator of or effectiveness of the management of peripheral neuropathy. This could support the development of interventions to prevent complications such as foot ulceration or Charcot's foot. Copyright © 2018 Korean Diabetes Association.

A New Calibration Methodology for Thorax and Upper Limbs Motion Capture in Children Using Magneto and Inertial Sensors

Directory of Open Access Journals (Sweden)

Luca Ricci

2014-01-01

Full Text Available Recent advances in wearable sensor technologies for motion capture have produced devices, mainly based on magneto and inertial measurement units (M-IMU, that are now suitable for out-of-the-lab use with children. In fact, the reduced size, weight and the wireless connectivity meet the requirement of minimum obtrusivity and give scientists the possibility to analyze children’s motion in daily life contexts. Typical use of magneto and inertial measurement units (M-IMU motion capture systems is based on attaching a sensing unit to each body segment of interest. The correct use of this setup requires a specific calibration methodology that allows mapping measurements from the sensors’ frames of reference into useful kinematic information in the human limbs’ frames of reference. The present work addresses this specific issue, presenting a calibration protocol to capture the kinematics of the upper limbs and thorax in typically developing (TD children. The proposed method allows the construction, on each body segment, of a meaningful system of coordinates that are representative of real physiological motions and that are referred to as functional frames (FFs. We will also present a novel cost function for the Levenberg–Marquardt algorithm, to retrieve the rotation matrices between each sensor frame (SF and the corresponding FF. Reported results on a group of 40 children suggest that the method is repeatable and reliable, opening the way to the extensive use of this technology for out-of-the-lab motion capture in children.

Hospital Organization and Importance of an Interventional Radiology Inpatient Admitting Service: Italian Single-Center 3-Year Experience

International Nuclear Information System (INIS)

Simonetti, Giovanni; Bollero, Enrico; Ciarrapico, Anna Micaela; Gandini, Roberto; Konda, Daniel; Bartolucci, Alberto; Di Primio, Massimiliano; Mammucari, Matteo; Chiocchi, Marcello; D'Alba, Fabrizio; Masala, Salvatore

2009-01-01

In June 2005 a Complex Operating Unit of Interventional Radiology (COUIR), consisting of an outpatient visit service, an inpatient admitting service with four beds, and a day-hospital service with four beds was installed at our department. Between June 2005 and May 2008, 1772 and 861 well-screened elective patients were admitted to the inpatient ward of the COUIR and to the Internal Medicine Unit (IMU) or Surgery Unit (SU) of our hospital, respectively, and treated with IR procedures. For elective patients admitted to the COUIR's inpatient ward, hospital stays were significantly shorter and differences between reimbursements and costs were significantly higher for almost all IR procedures compared to those for patients admitted to the IMU and SU (Student's t-test for unpaired data, p < 0.05). The results of the 3-year activity show that the activation of a COUIR with an inpatient admitting service, and the better organization of the patient pathway that came with it, evidenced more efficient use of resources, with the possibility for the hospital to save money and obtain positive margins (differences between reimbursements and costs). During 3 years of activity, the inpatient admitting service of our COUIR yielded a positive difference between reimbursements and effective costs of Euro 1,009,095.35. The creation of an inpatient IR service and the admission of well-screened elective patients allowed short hospitalization times, reduction of waiting lists, and a positive economic outcome.

DEVELOPMENT OF A PEDESTRIAN INDOOR NAVIGATION SYSTEM BASED ON MULTI-SENSOR FUSION AND FUZZY LOGIC ESTIMATION ALGORITHMS

Directory of Open Access Journals (Sweden)

Y. C. Lai

2015-05-01

Full Text Available This paper presents a pedestrian indoor navigation system based on the multi-sensor fusion and fuzzy logic estimation algorithms. The proposed navigation system is a self-contained dead reckoning navigation that means no other outside signal is demanded. In order to achieve the self-contained capability, a portable and wearable inertial measure unit (IMU has been developed. Its adopted sensors are the low-cost inertial sensors, accelerometer and gyroscope, based on the micro electro-mechanical system (MEMS. There are two types of the IMU modules, handheld and waist-mounted. The low-cost MEMS sensors suffer from various errors due to the results of manufacturing imperfections and other effects. Therefore, a sensor calibration procedure based on the scalar calibration and the least squares methods has been induced in this study to improve the accuracy of the inertial sensors. With the calibrated data acquired from the inertial sensors, the step length and strength of the pedestrian are estimated by multi-sensor fusion and fuzzy logic estimation algorithms. The developed multi-sensor fusion algorithm provides the amount of the walking steps and the strength of each steps in real-time. Consequently, the estimated walking amount and strength per step are taken into the proposed fuzzy logic estimation algorithm to estimates the step lengths of the user. Since the walking length and direction are both the required information of the dead reckoning navigation, the walking direction is calculated by integrating the angular rate acquired by the gyroscope of the developed IMU module. Both the walking length and direction are calculated on the IMU module and transmit to a smartphone with Bluetooth to perform the dead reckoning navigation which is run on a self-developed APP. Due to the error accumulating of dead reckoning navigation, a particle filter and a pre-loaded map of indoor environment have been applied to the APP of the proposed navigation system

Development of a Pedestrian Indoor Navigation System Based on Multi-Sensor Fusion and Fuzzy Logic Estimation Algorithms

Science.gov (United States)

Lai, Y. C.; Chang, C. C.; Tsai, C. M.; Lin, S. Y.; Huang, S. C.

2015-05-01

This paper presents a pedestrian indoor navigation system based on the multi-sensor fusion and fuzzy logic estimation algorithms. The proposed navigation system is a self-contained dead reckoning navigation that means no other outside signal is demanded. In order to achieve the self-contained capability, a portable and wearable inertial measure unit (IMU) has been developed. Its adopted sensors are the low-cost inertial sensors, accelerometer and gyroscope, based on the micro electro-mechanical system (MEMS). There are two types of the IMU modules, handheld and waist-mounted. The low-cost MEMS sensors suffer from various errors due to the results of manufacturing imperfections and other effects. Therefore, a sensor calibration procedure based on the scalar calibration and the least squares methods has been induced in this study to improve the accuracy of the inertial sensors. With the calibrated data acquired from the inertial sensors, the step length and strength of the pedestrian are estimated by multi-sensor fusion and fuzzy logic estimation algorithms. The developed multi-sensor fusion algorithm provides the amount of the walking steps and the strength of each steps in real-time. Consequently, the estimated walking amount and strength per step are taken into the proposed fuzzy logic estimation algorithm to estimates the step lengths of the user. Since the walking length and direction are both the required information of the dead reckoning navigation, the walking direction is calculated by integrating the angular rate acquired by the gyroscope of the developed IMU module. Both the walking length and direction are calculated on the IMU module and transmit to a smartphone with Bluetooth to perform the dead reckoning navigation which is run on a self-developed APP. Due to the error accumulating of dead reckoning navigation, a particle filter and a pre-loaded map of indoor environment have been applied to the APP of the proposed navigation system to extend its

Using inertial measurement units originally developed for biomechanics for modal testing of civil engineering structures

Science.gov (United States)

Hester, David; Brownjohn, James; Bocian, Mateusz; Xu, Yan; Quattrone, Antonino

2018-05-01

This paper explores the use of wireless Inertial Measurement Units (IMU) originally developed for bio-mechanical research applications for modal testing of civil engineering infrastructure. Due to their biomechanics origin, these devices combine a triaxial accelerometer with gyroscopes and magnetometers for orientation, as well as on board data logging capability and wireless communication for optional data streaming and to coordinate synchronisation with other IMUs in a network. The motivation for application to civil structures is that their capabilities and simple operating procedures make them suitable for modal testing of many types of civil infrastructure of limited dimension including footbridges and floors while also enabling recovering of dynamic forces generated and applied to structures by moving humans. To explore their capabilities in civil applications, the IMUs are evaluated through modal tests on three different structures with increasing challenge of spatial and environmental complexity. These are, a full-scale floor mock-up in a laboratory, a short span road bridge and a seven story office tower. For each case, the results from the IMUs are compared with those from a conventional wired system to identify the limitations. The main conclusion is that the relatively high noise floor and limited communication range will not be a serious limitation in the great majority of typical civil modal test applications where convenient operation is a significant advantage over conventional wired systems.

Calibration Procedures in Mid Format Camera Setups

Science.gov (United States)

Pivnicka, F.; Kemper, G.; Geissler, S.

2012-07-01

A growing number of mid-format cameras are used for aerial surveying projects. To achieve a reliable and geometrically precise result also in the photogrammetric workflow, awareness on the sensitive parts is important. The use of direct referencing systems (GPS/IMU), the mounting on a stabilizing camera platform and the specific values of the mid format camera make a professional setup with various calibration and misalignment operations necessary. An important part is to have a proper camera calibration. Using aerial images over a well designed test field with 3D structures and/or different flight altitudes enable the determination of calibration values in Bingo software. It will be demonstrated how such a calibration can be performed. The direct referencing device must be mounted in a solid and reliable way to the camera. Beside the mechanical work especially in mounting the camera beside the IMU, 2 lever arms have to be measured in mm accuracy. Important are the lever arms from the GPS Antenna to the IMU's calibrated centre and also the lever arm from the IMU centre to the Camera projection centre. In fact, the measurement with a total station is not a difficult task but the definition of the right centres and the need for using rotation matrices can cause serious accuracy problems. The benefit of small and medium format cameras is that also smaller aircrafts can be used. Like that, a gyro bases stabilized platform is recommended. This causes, that the IMU must be mounted beside the camera on the stabilizer. The advantage is, that the IMU can be used to control the platform, the problematic thing is, that the IMU to GPS antenna lever arm is floating. In fact we have to deal with an additional data stream, the values of the movement of the stabiliser to correct the floating lever arm distances. If the post-processing of the GPS-IMU data by taking the floating levers into account, delivers an expected result, the lever arms between IMU and camera can be applied

Teen Sized Humanoid Robot: Archie

Science.gov (United States)

Baltes, Jacky; Byagowi, Ahmad; Anderson, John; Kopacek, Peter

This paper describes our first teen sized humanoid robot Archie. This robot has been developed in conjunction with Prof. Kopacek’s lab from the Technical University of Vienna. Archie uses brushless motors and harmonic gears with a novel approach to position encoding. Based on our previous experience with small humanoid robots, we developed software to create, store, and play back motions as well as control methods which automatically balance the robot using feedback from an internal measurement unit (IMU).

Hybrid Kalman and unscented Kalman filters for INS/GPS integrated system considering constant lever arm effect

Institute of Scientific and Technical Information of China (English)

常国宾; 柳明

2015-01-01

In inertial navigation system (INS) and global positioning system (GPS) integrated system, GPS antennas are usually not located at the same location as the inertial measurement unit (IMU) of the INS, so the lever arm effect exists, which makes the observation equation highly nonlinear. The INS/GPS integration with constant lever arm effect is studied. The position relation of IMU and GPS’s antenna is represented in the earth centered earth fixed frame, while the velocity relation of these two systems is represented in local horizontal frame. Due to the small integration time interval of INS, i.e. 0.1 s in this work, the nonlinearity in the INS error equation is trivial, so the linear INS error model is constructed and addressed by Kalman filter’s prediction step. On the other hand, the high nonlinearity in the observation equation due to lever arm effect is addressed by unscented Kalman filter’s update step to attain higher accuracy and better applicability. Simulation is designed and the performance of the hybrid filter is validated.

Fault Diagnosis of a Reconfigurable Crawling–Rolling Robot Based on Support Vector Machines

Directory of Open Access Journals (Sweden)

Karthikeyan Elangovan

2017-10-01

Full Text Available As robots begin to perform jobs autonomously, with minimal or no human intervention, a new challenge arises: robots also need to autonomously detect errors and recover from faults. In this paper, we present a Support Vector Machine (SVM-based fault diagnosis system for a bio-inspired reconfigurable robot named Scorpio. The diagnosis system needs to detect and classify faults while Scorpio uses its crawling and rolling locomotion modes. Specifically, we classify between faulty and non-faulty conditions by analyzing onboard Inertial Measurement Unit (IMU sensor data. The data capture nine different locomotion gaits, which include rolling and crawling modes, at three different speeds. Statistical methods are applied to extract features and to reduce the dimensionality of original IMU sensor data features. These statistical features were given as inputs for training and testing. Additionally, the c-Support Vector Classification (c-SVC and nu-SVC models of SVM, and their fault classification accuracies, were compared. The results show that the proposed SVM approach can be used to autonomously diagnose locomotion gait faults while the reconfigurable robot is in operation.

Automated pavement horizontal curve measurement methods based on inertial measurement unit and 3D profiling data

Directory of Open Access Journals (Sweden)

Wenting Luo

2016-04-01

Full Text Available Pavement horizontal curve is designed to serve as a transition between straight segments, and its presence may cause a series of driving-related safety issues to motorists and drivers. As is recognized that traditional methods for curve geometry investigation are time consuming, labor intensive, and inaccurate, this study attempts to develop a method that can automatically conduct horizontal curve identification and measurement at network level. The digital highway data vehicle (DHDV was utilized for data collection, in which three Euler angles, driving speed, and acceleration of survey vehicle were measured with an inertial measurement unit (IMU. The 3D profiling data used for cross slope calibration was obtained with PaveVision3D Ultra technology at 1 mm resolution. In this study, the curve identification was based on the variation of heading angle, and the curve radius was calculated with kinematic method, geometry method, and lateral acceleration method. In order to verify the accuracy of the three methods, the analysis of variance (ANOVA test was applied by using the control variable of curve radius measured by field test. Based on the measured curve radius, a curve safety analysis model was used to predict the crash rates and safe driving speeds at horizontal curves. Finally, a case study on 4.35 km road segment demonstrated that the proposed method could efficiently conduct network level analysis.

An integrated autonomous rendezvous and docking system architecture using Centaur modern avionics

Science.gov (United States)

Nelson, Kurt

1991-01-01

The avionics system for the Centaur upper stage is in the process of being modernized with the current state-of-the-art in strapdown inertial guidance equipment. This equipment includes an integrated flight control processor with a ring laser gyro based inertial guidance system. This inertial navigation unit (INU) uses two MIL-STD-1750A processors and communicates over the MIL-STD-1553B data bus. Commands are translated into load activation through a Remote Control Unit (RCU) which incorporates the use of solid state relays. Also, a programmable data acquisition system replaces separate multiplexer and signal conditioning units. This modern avionics suite is currently being enhanced through independent research and development programs to provide autonomous rendezvous and docking capability using advanced cruise missile image processing technology and integrated GPS navigational aids. A system concept was developed to combine these technologies in order to achieve a fully autonomous rendezvous, docking, and autoland capability. The current system architecture and the evolution of this architecture using advanced modular avionics concepts being pursued for the National Launch System are discussed.

Estimation of attitudes from a low-cost miniaturized inertial platform ...

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

from the output of the three angular rate sensors in the platform using the strapdown .... studied, modelled and compensated in order to reach an adequate quality of the .... 6. Matlab/Simulink implementation. The Kalman Filter-based fusion ...

Development and Flight Test of a Robust Optical-Inertial Navigation System Using Low-Cost Sensors

Science.gov (United States)

2008-03-01

for this test. Though, marketed as a GPS/INS, it was in fact used simply as an IMU for this test. The raw inertial measurement data (from the...Performance Evaluation of Low Cost MEMS-Based IMU Integrated With GPS for Land Vehicle Navigation Application. MS Thesis, UCGE Reports Number

Unmanned Systems: A Lab-Based Robotic Arm for Grasping

Science.gov (United States)

2015-06-01

14 Figure 10. Arduino Uno from............................................................................................15...flex sensors shown in Figure 8. 13 Figure 8. Fully assembled glove controller with flex sensors, IMU and Arduino Uno Microcontroller. 1...describe orientation (in degrees) around a single reference point in three-dimensional space [1]. Arduino Uno Microcontroller Adafruit IMU Flex

An in situ hand calibration method using a pseudo-observation scheme for low-end inertial measurement units

International Nuclear Information System (INIS)

Li, You; Niu, Xiaoji; Zhang, Quan; Zhang, Hongping; Shi, Chuang

2012-01-01

MEMS chips have become ideal candidates for various applications since they are small sized, light weight, have low power consumption and are extremely low cost and reliable. However, the performance of MEMS sensors, especially their biases and scale factors, is highly dependent on environmental conditions such as temperature. Thus a quick and convenient calibration is needed to be conducted by users in field without any external equipment or any expert knowledge of calibration. A novel and efficient in situ hand calibration method is presented to meet these demands in this paper. The algorithm of the proposed calibration method makes use of the navigation algorithm of the loosely-coupled GPS/INS integrated systems, but replaces the GPS observations with a kind of pseudo-observations, which can be stated as follows: if an inertial measurement unit (IMU) was rotating approximately around its measurement center, the range of its position and its linear velocity both would be within a limited scope. Using a Kalman filtering algorithm, the biases and scale factors of both accelerometer triad and gyroscope triad can be calibrated together within a short period (about 30 s), requiring only motions by hands. Real test results show that the proposed method is suitable for most consumer grade MEMS IMUs due to its zero cost, easy operation and sufficient accuracy. (paper)

Omnidirectional vision applied to Unmanned Aerial Vehicles (UAVs) attitude and heading estimation

OpenAIRE

Mondragon, Ivan F.; Campoy, Pascual; Martinez, Carol; Olivares Mendez, Miguel Angel

2010-01-01

This paper presents an aircraft attitude and heading estimator using catadioptric images as a principal sensor for UAV or as a redundant system for IMU (Inertial Measure Unit) and gyro sensors. First, we explain how the unified theory for central catadioptric cameras is used for attitude and heading estimation, explaining how the skyline is projected on the catadioptric image and how it is segmented and used to calculate the UAV's attitude. Then, we use appearance images to obtain a visual co...

Loose Coupling of Wearable-Based INSs with Automatic Heading Evaluation

OpenAIRE

Bousdar Ahmed, Dina; Munoz Diaz, Estefania

2017-01-01

Position tracking of pedestrians by means of inertial sensors is a highly explored field of research. In fact, there are already many approaches to implement inertial navigation systems (INSs). However, most of them use a single inertial measurement unit (IMU) attached to the pedestrian’s body. Since wearable-devices will be given items in the future, this work explores the implementation of an INS using two wearable-based IMUs. A loosely coupled approach is proposed to combine the outputs of...

CALIBRATION PROCEDURES IN MID FORMAT CAMERA SETUPS

Directory of Open Access Journals (Sweden)

F. Pivnicka

2012-07-01

Full Text Available A growing number of mid-format cameras are used for aerial surveying projects. To achieve a reliable and geometrically precise result also in the photogrammetric workflow, awareness on the sensitive parts is important. The use of direct referencing systems (GPS/IMU, the mounting on a stabilizing camera platform and the specific values of the mid format camera make a professional setup with various calibration and misalignment operations necessary. An important part is to have a proper camera calibration. Using aerial images over a well designed test field with 3D structures and/or different flight altitudes enable the determination of calibration values in Bingo software. It will be demonstrated how such a calibration can be performed. The direct referencing device must be mounted in a solid and reliable way to the camera. Beside the mechanical work especially in mounting the camera beside the IMU, 2 lever arms have to be measured in mm accuracy. Important are the lever arms from the GPS Antenna to the IMU's calibrated centre and also the lever arm from the IMU centre to the Camera projection centre. In fact, the measurement with a total station is not a difficult task but the definition of the right centres and the need for using rotation matrices can cause serious accuracy problems. The benefit of small and medium format cameras is that also smaller aircrafts can be used. Like that, a gyro bases stabilized platform is recommended. This causes, that the IMU must be mounted beside the camera on the stabilizer. The advantage is, that the IMU can be used to control the platform, the problematic thing is, that the IMU to GPS antenna lever arm is floating. In fact we have to deal with an additional data stream, the values of the movement of the stabiliser to correct the floating lever arm distances. If the post-processing of the GPS-IMU data by taking the floating levers into account, delivers an expected result, the lever arms between IMU and

PUSHBROOM HYPERSPECTRAL IMAGING FROM AN UNMANNED AIRCRAFT SYSTEM (UAS) – GEOMETRIC PROCESSINGWORKFLOW AND ACCURACY ASSESSMENT

KAUST Repository

Turner, D.

2017-08-31

In this study, we assess two push broom hyperspectral sensors as carried by small (10-15 kg) multi-rotor Unmanned Aircraft Systems (UAS). We used a Headwall Photonics micro-Hyperspec push broom sensor with 324 spectral bands (4-5 nm FWHM) and a Headwall Photonics nano-Hyperspec sensor with 270 spectral bands (6 nm FWHM) both in the VNIR spectral range (400-1000 nm). A gimbal was used to stabilise the sensors in relation to the aircraft flight dynamics, and for the micro-Hyperspec a tightly coupled dual frequency Global Navigation Satellite System (GNSS) receiver, an Inertial Measurement Unit (IMU), and Machine Vision Camera (MVC) were used for attitude and position determination. For the nano-Hyperspec, a navigation grade GNSS system and IMU provided position and attitude data. This study presents the geometric results of one flight over a grass oval on which a dense Ground Control Point (GCP) network was deployed. The aim being to ascertain the geometric accuracy achievable with the system. Using the PARGE software package (ReSe - Remote Sensing Applications) we ortho-rectify the push broom hyperspectral image strips and then quantify the accuracy of the ortho-rectification by using the GCPs as check points. The orientation (roll, pitch, and yaw) of the sensor is measured by the IMU. Alternatively imagery from a MVC running at 15 Hz, with accurate camera position data can be processed with Structure from Motion (SfM) software to obtain an estimated camera orientation. In this study, we look at which of these data sources will yield a flight strip with the highest geometric accuracy.

The UAV take-off and landing system used for small areas of mobile vehicles

Science.gov (United States)

Ren, Tian-Yu; Duanmu, Qing-Duo; Wu, Bo-Qi

2018-03-01

In order to realize an UAV formation cluster system based on the current GPS and the fault and insufficiency of Beidou integrated navigation system in strong jamming environment. Due to the impact of the compass on the plane crash, navigation system error caused by the mobile area to help reduce the need for large landing sites and not in the small fast moving area to achieve the reality of the landing. By using Strapdown inertial and all-optical system to form Composite UAV flight control system, the photoelectric composite strapdown inertial coupling is realized, and through the laser and microwave telemetry link compound communication mechanism, using all-optical strapdown inertial and visual navigation system to solve the deviation of take-off and landing caused by electromagnetic interference, all-optical bidirectional data link realizes two-way position correction of landing site and aircraft, thus achieves the accurate recovery of UAV formation cluster in the mobile narrow area which the traditional navigation system can't realize. This system is a set of efficient unmanned aerial vehicle Group Take-off/descending system, which is suitable for many tasks, and not only realizes the reliable continuous navigation under the complex electromagnetic interference environment, moreover, the intelligent flight and Take-off and landing of unmanned aerial vehicles relative to the fast moving and small recovery sites in complex electromagnetic interference environment can not only improve the safe operation rate of unmanned aerial vehicle, but also guarantee the operation safety of the aircraft, and the more has important social value for the application foreground of the aircraft.

On Inertial Body Tracking in the Presence of Model Calibration Errors.

Science.gov (United States)

Miezal, Markus; Taetz, Bertram; Bleser, Gabriele

2016-07-22

In inertial body tracking, the human body is commonly represented as a biomechanical model consisting of rigid segments with known lengths and connecting joints. The model state is then estimated via sensor fusion methods based on data from attached inertial measurement units (IMUs). This requires the relative poses of the IMUs w.r.t. the segments-the IMU-to-segment calibrations, subsequently called I2S calibrations-to be known. Since calibration methods based on static poses, movements and manual measurements are still the most widely used, potentially large human-induced calibration errors have to be expected. This work compares three newly developed/adapted extended Kalman filter (EKF) and optimization-based sensor fusion methods with an existing EKF-based method w.r.t. their segment orientation estimation accuracy in the presence of model calibration errors with and without using magnetometer information. While the existing EKF-based method uses a segment-centered kinematic chain biomechanical model and a constant angular acceleration motion model, the newly developed/adapted methods are all based on a free segments model, where each segment is represented with six degrees of freedom in the global frame. Moreover, these methods differ in the assumed motion model (constant angular acceleration, constant angular velocity, inertial data as control input), the state representation (segment-centered, IMU-centered) and the estimation method (EKF, sliding window optimization). In addition to the free segments representation, the optimization-based method also represents each IMU with six degrees of freedom in the global frame. In the evaluation on simulated and real data from a three segment model (an arm), the optimization-based method showed the smallest mean errors, standard deviations and maximum errors throughout all tests. It also showed the lowest dependency on magnetometer information and motion agility. Moreover, it was insensitive w.r.t. I2S position and

Reconstruction of Twist Torque in Main Parachute Risers

Science.gov (United States)

Day, Joshua D.

2015-01-01

The reconstruction of twist torque in the Main Parachute Risers of the Capsule Parachute Assembly System (CPAS) has been successfully used to validate CPAS Model Memo conservative twist torque equations. Reconstruction of basic, one degree of freedom drop tests was used to create a functional process for the evaluation of more complex, rigid body simulation. The roll, pitch, and yaw of the body, the fly-out angles of the parachutes, and the relative location of the parachutes to the body are inputs to the torque simulation. The data collected by the Inertial Measurement Unit (IMU) was used to calculate the true torque. The simulation then used photogrammetric and IMU data as inputs into the Model Memo equations. The results were then compared to the true torque results to validate the Model Memo equations. The Model Memo parameters were based off of steel risers and the parameters will need to be re-evaluated for different materials. Photogrammetric data was found to be more accurate than the inertial data in accounting for the relative rotation between payload and cluster. The Model Memo equations were generally a good match and when not matching were generally conservative.

A Vision/Inertia Integrated Positioning Method Using Position and Orientation Matching

Directory of Open Access Journals (Sweden)

Xiaoyue Zhang

2017-01-01

Full Text Available A vision/inertia integrated positioning method using position and orientation matching which can be adopted on intelligent vehicle such as automated guided vehicle (AGV and mobile robot is proposed in this work. The method is introduced firstly. Landmarks are placed into the navigation field and camera and inertial measurement unit (IMU are installed on the vehicle. Vision processor calculates the azimuth and position information from the pictures which include artificial landmarks with the known direction and position. Inertial navigation system (INS calculates the azimuth and position of vehicle in real time and the calculated pixel position of landmark can be computed from the INS output position. Then the needed mathematical models are established and integrated navigation is implemented by Kalman filter with the observation of azimuth and the calculated pixel position of landmark. Navigation errors and IMU errors are estimated and compensated in real time so that high precision navigation results can be got. Finally, simulation and test are performed, respectively. Both simulation and test results prove that this vision/inertia integrated positioning method using position and orientation matching has feasibility and it can achieve centimeter-level autonomic continuous navigation.

Extraction and Analysis of Respiratory Motion Using Wearable Inertial Sensor System during Trunk Motion

Directory of Open Access Journals (Sweden)

Apoorva Gaidhani

2017-12-01

Full Text Available Respiratory activity is an essential vital sign of life that can indicate changes in typical breathing patterns and irregular body functions such as asthma and panic attacks. Many times, there is a need to monitor breathing activity while performing day-to-day functions such as standing, bending, trunk stretching or during yoga exercises. A single IMU (inertial measurement unit can be used in measuring respiratory motion; however, breathing motion data may be influenced by a body trunk movement that occurs while recording respiratory activity. This research employs a pair of wireless, wearable IMU sensors custom-made by the Department of Electrical Engineering at San Diego State University. After appropriate sensor placement for data collection, this research applies principles of robotics, using the Denavit-Hartenberg convention, to extract relative angular motion between the two sensors. One of the obtained relative joint angles in the “Sagittal” plane predominantly yields respiratory activity. An improvised version of the proposed method and wearable, wireless sensors can be suitable to extract respiratory information while performing sports or exercises, as they do not restrict body motion or the choice of location to gather data.

Quantifying infant physical interactions using sensorized toys in a natural play environment.

Science.gov (United States)

Goyal, Vatsala; Torres, Wilson; Rai, Roshan; Shofer, Frances; Bogen, Daniel; Bryant, Phillip; Prosser, Laura; Johnson, Michelle J

2017-07-01

Infants with developmental delays must be detected early in their development to minimize the progression of motor and neurological impairments. Our objective is to quantify how sensorized toys in a natural play environment can promote infant-toy physical interactions. We created a hanging elephant toy, equipped with an inertial measurement unit (IMU), a pressure transducer, and multiple feedback sensors, to be a hand-grasping toy. We used a 3 DoF robotic model with inputs from the IMU to calculate multiple kinematic metrics and an equation to calculate haptic metrics from the pressure transducer. Six typical infants were tested in the gym set-up. Three infants interacted with the toy for more than half the trial time. The youngest infant exhibited the largest toy displacement with ΔD = 27.6 cm, while the oldest infant squeezed the toy with the largest mean pressure of 4.5 kPa. More data on on both typical and atypical infants needs to be collected. After testing atypical infants in the SmarToyGym set-up, we will be able to identify interaction metrics that differentiate atypical and typical infants.

Skew redundant MEMS IMU calibration using a Kalman filter

International Nuclear Information System (INIS)

Jafari, M; Sahebjameyan, M; Moshiri, B; Najafabadi, T A

2015-01-01

In this paper, a novel calibration procedure for skew redundant inertial measurement units (SRIMUs) based on micro-electro mechanical systems (MEMS) is proposed. A general model of the SRIMU measurements is derived which contains the effects of bias, scale factor error and misalignments. For more accuracy, the effect of lever arms of the accelerometers to the center of the table are modeled and compensated in the calibration procedure. Two separate Kalman filters (KFs) are proposed to perform the estimation of error parameters for gyroscopes and accelerometers. The predictive error minimization (PEM) stochastic modeling method is used to simultaneously model the effect of bias instability and random walk noise on the calibration Kalman filters to diminish the biased estimations. The proposed procedure is simulated numerically and has expected experimental results. The calibration maneuvers are applied using a two-axis angle turntable in a way that the persistency of excitation (PE) condition for parameter estimation is met. For this purpose, a trapezoidal calibration profile is utilized to excite different deterministic error parameters of the accelerometers and a pulse profile is used for the gyroscopes. Furthermore, to evaluate the performance of the proposed KF calibration method, a conventional least squares (LS) calibration procedure is derived for the SRIMUs and the simulation and experimental results compare the functionality of the two proposed methods with each other. (paper)

75 FR 59745 - In the Matter of: Certain Components for Installation of Marine Autopilots With GPS or IMU...

Science.gov (United States)

2010-09-28

..., Southampton Road. Portsmouth Hampshire, PO6 4QB, United Kingdom. Raymarine Inc., 21 Manchester Street... violations of section 337 based upon the importation into the United States, the sale for importation, and the sale within the United States after importation of certain installation of marine autopilots with...

Development of a tool to capture of the human movement for biometric analysis

International Nuclear Information System (INIS)

Chacon Taylor, Marco; Ortiz Cubero, Esteban

2013-01-01

A tool is developed for the measurement of stability static and dynamic of people. The Wii Remote TM was chosen as the system to capture body movement. The measurements of the gyroscopes and accelerometers are obtained from the wiimote adhered to a part of the human body. Dynamic stability parameters are calculated using the wiimote. Dynamic stability data are compared between IMU (Inertial Measurement Unit) and wiimote. The position, orientation, etc. are recreated from measurements of the wiimote. The study of new motion capture techniques is recommended for the analysis of dynamic stability [es

GPS/INS Sensor Fusion Using GPS Wind up Model

Science.gov (United States)

Williamson, Walton R. (Inventor)

2013-01-01

A method of stabilizing an inertial navigation system (INS), includes the steps of: receiving data from an inertial navigation system; and receiving a finite number of carrier phase observables using at least one GPS receiver from a plurality of GPS satellites; calculating a phase wind up correction; correcting at least one of the finite number of carrier phase observables using the phase wind up correction; and calculating a corrected IMU attitude or velocity or position using the corrected at least one of the finite number of carrier phase observables; and performing a step selected from the steps consisting of recording, reporting, or providing the corrected IMU attitude or velocity or position to another process that uses the corrected IMU attitude or velocity or position. A GPS stabilized inertial navigation system apparatus is also described.

Enhanced Pedestrian Navigation Based on Course Angle Error Estimation Using Cascaded Kalman Filters.

Science.gov (United States)

Song, Jin Woo; Park, Chan Gook

2018-04-21

An enhanced pedestrian dead reckoning (PDR) based navigation algorithm, which uses two cascaded Kalman filters (TCKF) for the estimation of course angle and navigation errors, is proposed. The proposed algorithm uses a foot-mounted inertial measurement unit (IMU), waist-mounted magnetic sensors, and a zero velocity update (ZUPT) based inertial navigation technique with TCKF. The first stage filter estimates the course angle error of a human, which is closely related to the heading error of the IMU. In order to obtain the course measurements, the filter uses magnetic sensors and a position-trace based course angle. For preventing magnetic disturbance from contaminating the estimation, the magnetic sensors are attached to the waistband. Because the course angle error is mainly due to the heading error of the IMU, and the characteristic error of the heading angle is highly dependent on that of the course angle, the estimated course angle error is used as a measurement for estimating the heading error in the second stage filter. At the second stage, an inertial navigation system-extended Kalman filter-ZUPT (INS-EKF-ZUPT) method is adopted. As the heading error is estimated directly by using course-angle error measurements, the estimation accuracy for the heading and yaw gyro bias can be enhanced, compared with the ZUPT-only case, which eventually enhances the position accuracy more efficiently. The performance enhancements are verified via experiments, and the way-point position error for the proposed method is compared with those for the ZUPT-only case and with other cases that use ZUPT and various types of magnetic heading measurements. The results show that the position errors are reduced by a maximum of 90% compared with the conventional ZUPT based PDR algorithms.

Developmental Test of the Honeywell Laser Inertial Navigation System (LINS)

Science.gov (United States)

1975-11-01

The ISA contains three Systron Donner 4841F-10 single axis accelerometers and three Honeywell GG1300- AEOI laser gyros in an orthogonal strapdown...DIAG.1,kM AN.D PHYSICAL CHARACTERISTICS The GG1300- AEOI laser gyro, shown schematically in Figure 2, has the following performance goals which were

Inertial and GPS data integration for positioning and tracking of GPR

Science.gov (United States)

Chicarella, Simone; D'Alvano, Alessandro; Ferrara, Vincenzo; Frezza, Fabrizio; Pajewski, Lara

2015-04-01

Nowadays many applications and studies use a Global Positioning System (GPS) to integrate Ground-Penetrating Radar (GPR) data [1-2]. The aim is the production of detailed detection maps that are geo-referenced and superimposable on geographic maps themes. GPS provides data to determine static positioning, and to track the mobile detection system path on the land. A low-cost standard GPS, like GPS-622R by RF Solutions Ltd, allows accuracy around 2.5 m CEP (Circular Error Probability), and a maximum update rate of 10 Hz. These accuracy and update rate are satisfying values when we evaluate positioning datum, but they are unsuitable for precision tracking of a speedy-mobile GPR system. In order to determine the relative displacements with respect to an initial position on the territory, an Inertial Measurement Unit (IMU) can be used. Some inertial-system applications for GPR tracking have been presented in recent studies [3-4]. The integration of both GPS and IMU systems is the aim of our work, in order to increase GPR applicability, e.g. the case of a GPR mounted on an unmanned aerial vehicle for the detection of people buried under avalanches [5]. In this work, we will present the design, realization and experimental characterization of our electronic board that includes GPS-622R and AltIMU-10 v3 by Pololu. The latter comprises an inertial-measurement unit and an altimeter. In particular, the IMU adopts L3GD20 gyro and LSM303D accelerometer and magnetometer; the digital barometer LPS331AP provides data for altitude evaluation. The prototype of our system for GPR positioning and tracking is based on an Arduino microcontroller board. Acknowledgement This work benefited from networking activities carried out within the EU funded COST Action TU1208 'Civil Engineering Applications of Ground Penetrating Radar. ' References [1] M. Solla, X. Núñez-Nieto, M. Varela-González, J. Martínez-Sánchez, and P. Arias, 'GPR for Road Inspection: georeferencing and efficient

Sensing Passive Eye Response to Impact Induced Head Acceleration Using MEMS IMUs.

Science.gov (United States)

Meng, Yuan; Bottenfield, Brent; Bolding, Mark; Liu, Lei; Adams, Mark L

2018-02-01

The eye may act as a surrogate for the brain in response to head acceleration during an impact. Passive eye movements in a dynamic system are sensed by microelectromechanical systems (MEMS) inertial measurement units (IMU) in this paper. The technique is validated using a three-dimensional printed scaled human skull model and on human volunteers by performing drop-and-impact experiments with ribbon-style flexible printed circuit board IMUs inserted in the eyes and reference IMUs on the heads. Data are captured by a microcontroller unit and processed using data fusion. Displacements are thus estimated and match the measured parameters. Relative accelerations and displacements of the eye to the head are computed indicating the influence of the concussion causing impacts.

The Effectiveness of Counterterrorist Policies in Uzbekistan

Science.gov (United States)

2012-12-01

Revival of the Islamic Movement of Uzbekistan (IMU)? Studies in Conflict & Terrorism 27, no.6 (2004): 505 –530. 17. “Central Asia: Are Radical... NIA , February 8, 2011. 66 censorship on the public media limited the public access to such information in Uzbekistan. The activists of human and...of the Islamic Movement of Uzbekistan (IMU)?” Studies in Conflict & Terrorism 27, no.6, (2004): 505 –530. Accessed November 23, 2011. http

Internal medicine network: a new way of thinking hospital-territory integration and public-private partnership

Directory of Open Access Journals (Sweden)

Filomena Pietrantonio

2016-10-01

Full Text Available This working proposal aims to establish an Internal Medicine Network (IMN model for the appropriate management of the poly-pathological complex patient in the different phases of his illness natural hystory. The IMN is based on an organization recalling the Hub and Spoke system already used for existing specialized networks. The Internal Medicine Unit (IMU is the natural destination of acutely ill patients suffering from systemic or multi-organ diseases. Three are the IMU specific tasks: i to stabilize acute, severe, poly-pathologic and complex patients; ii to develop difficult etiological diagnosis in these patients and in those who should necessarily be admitted to the hospital, not being possible, for different reasons, alternative routes; iii to select the acute poly-pathological complex patient’s priorities. The expected results of a new model of integration system inside the IMN are: i reduction and rationalization of expenditure in the medical area, increasing effectiveness, quality and safety guaranteeing patient centrality; ii patients stratification based on characteristics of gravity, acute illness, estimated duration of hospitalization; iii reduction of inappropriate hospital admissions ensuring connections between hospital and primary care units; iv definition of different care pathways for patients hospitalized due to non-communicable diseases; v implementation of new common medical records. The public-private partnership inside the IMN could be able to increase appropriateness reducing health costs. Patient-centered problems assessment, together with integration, cooperation, coordination and effective communication are some simple rules useful to achieve tangible results in a complex system and the IMN model represents its practical application.

Spoofing Detection Using GNSS/INS/Odometer Coupling for Vehicular Navigation.

Science.gov (United States)

Broumandan, Ali; Lachapelle, Gérard

2018-04-24

Location information is one of the most vital information required to achieve intelligent and context-aware capability for various applications such as driverless cars. However, related security and privacy threats are a major holdback. With increasing focus on using Global Navigation Satellite Systems (GNSS) for autonomous navigation and related applications, it is important to provide robust navigation solutions, yet signal spoofing for illegal or covert transportation and misleading receiver timing is increasing and now frequent. Hence, detection and mitigation of spoofing attacks has become an important topic. Several contributions on spoofing detection have been made, focusing on different layers of a GNSS receiver. This paper focuses on spoofing detection utilizing self-contained sensors, namely inertial measurement units (IMUs) and vehicle odometer outputs. A spoofing detection approach based on a consistency check between GNSS and IMU/odometer mechanization is proposed. To detect a spoofing attack, the method analyses GNSS and IMU/odometer measurements independently during a pre-selected observation window and cross checks the solutions provided by GNSS and inertial navigation solution (INS)/odometer mechanization. The performance of the proposed method is verified in real vehicular environments. Mean spoofing detection time and detection performance in terms of receiver operation characteristics (ROC) in sub-urban and dense urban environments are evaluated.

Spoofing Detection Using GNSS/INS/Odometer Coupling for Vehicular Navigation

Directory of Open Access Journals (Sweden)

Ali Broumandan

2018-04-01

Full Text Available Location information is one of the most vital information required to achieve intelligent and context-aware capability for various applications such as driverless cars. However, related security and privacy threats are a major holdback. With increasing focus on using Global Navigation Satellite Systems (GNSS for autonomous navigation and related applications, it is important to provide robust navigation solutions, yet signal spoofing for illegal or covert transportation and misleading receiver timing is increasing and now frequent. Hence, detection and mitigation of spoofing attacks has become an important topic. Several contributions on spoofing detection have been made, focusing on different layers of a GNSS receiver. This paper focuses on spoofing detection utilizing self-contained sensors, namely inertial measurement units (IMUs and vehicle odometer outputs. A spoofing detection approach based on a consistency check between GNSS and IMU/odometer mechanization is proposed. To detect a spoofing attack, the method analyses GNSS and IMU/odometer measurements independently during a pre-selected observation window and cross checks the solutions provided by GNSS and inertial navigation solution (INS/odometer mechanization. The performance of the proposed method is verified in real vehicular environments. Mean spoofing detection time and detection performance in terms of receiver operation characteristics (ROC in sub-urban and dense urban environments are evaluated.

Pipeline Bending Strain Measurement and Compensation Technology Based on Wavelet Neural Network

Directory of Open Access Journals (Sweden)

Rui Li

2016-01-01

Full Text Available The bending strain of long distance oil and gas pipelines may lead to instability of the pipeline and failure of materials, which seriously deteriorates the transportation security of oil and gas. To locate the position of the bending strain for maintenance, an Inertial Measurement Unit (IMU is usually adopted in a Pipeline Inspection Gauge (PIG. The attitude data of the IMU is usually acquired to calculate the bending strain in the pipe. However, because of the vibrations in the pipeline and other system noises, the resulting bending strain calculations may be incorrect. To improve the measurement precision, a method, based on wavelet neural network, was proposed. To test the proposed method experimentally, a PIG with the proposed method is used to detect a straight pipeline. It can be obtained that the proposed method has a better repeatability and convergence than the original method. Furthermore, the new method is more accurate than the original method and the accuracy of bending strain is raised by about 23% compared to original method. This paper provides a novel method for precisely inspecting bending strain of long distance oil and gas pipelines and lays a foundation for improving the precision of inspection of bending strain of long distance oil and gas pipelines.

Position Tracking During Human Walking Using an Integrated Wearable Sensing System

Directory of Open Access Journals (Sweden)

Giulio Zizzo

2017-12-01

Full Text Available Progress has been made enabling expensive, high-end inertial measurement units (IMUs to be used as tracking sensors. However, the cost of these IMUs is prohibitive to their widespread use, and hence the potential of low-cost IMUs is investigated in this study. A wearable low-cost sensing system consisting of IMUs and ultrasound sensors was developed. Core to this system is an extended Kalman filter (EKF, which provides both zero-velocity updates (ZUPTs and Heuristic Drift Reduction (HDR. The IMU data was combined with ultrasound range measurements to improve accuracy. When a map of the environment was available, a particle filter was used to impose constraints on the possible user motions. The system was therefore composed of three subsystems: IMUs, ultrasound sensors, and a particle filter. A Vicon motion capture system was used to provide ground truth information, enabling validation of the sensing system. Using only the IMU, the system showed loop misclosure errors of 1% with a maximum error of 4–5% during walking. The addition of the ultrasound sensors resulted in a 15% reduction in the total accumulated error. Lastly, the particle filter was capable of providing noticeable corrections, which could keep the tracking error below 2% after the first few steps.

Serving an Indigenous community: Exploring the cultural competence of medical students in a rural setting

OpenAIRE

Wong, Chin Hoong; Chen, Lee Ping; Koh, Kwee Choy; Chua, Siew Houy; Jong, Darren Chee Hiung; Mohd Fauzi, Nurliyana Mardhiah; Lim, Sue Yin

2017-01-01

Since 2013, medical students from the International Medical University (IMU) in Malaysia have been providing primary healthcare services, under the supervision of faculty members, to the indigenous people living in Kampung Sebir. The project has allowed the students to learn experientially within a rural setting. This study aims to examine the cultural competence of IMU medical students through an examination of their perspective of the indigenous people who they serve and the role of this co...

Field testing of a next generation pointer/tracker for IRCM

Science.gov (United States)

Chapman, Stuart; Wildgoose, Iain; McDonald, Eric; Duncan, Stuart

2008-10-01

SELEX Galileo has been involved in the development, manufacture and support of high performance electro-optic pointing and stabilisation systems for over forty years. The Company currently supplies the pointer/trackers for the AN/AAQ-24(V) NEMESIS DIRCM system, for which over 1,000 combat-proven units have been produced and deployed in the US, the UK and other nations. In 2007, SELEX Galileo embarked on an internally funded programme to develop ECLIPSE, a new advanced, lightweight, low-cost IRCM pointer/tracker, exploiting the extensive knowledge and experience gained from previous targeting and IRCM programmes. The ECLIPSE design is centred on a low inertia, two-axis servo mechanism with a strap-down inertial sensor and advanced sightline control algorithms, allowing effective tracking through the nadir and providing superior sightline performance. The programme involved the production of three demonstrator units in 2007, and two pre-production units in 2008. The demonstrator units were first trialled as part of a NEMESIS DIRCM system in late 2007, and in April 2008 100% success was achieved in jamming live-fire demonstrations. Helicopter installation and ground testing of a UK only trials system is complete, initial flight testing has just begun, and the airborne test and evaluation scheduled for late summer 2008 will bring the ECLIPSE System to technology readiness to level 7 (TRL7). This paper describes the Eclipse performance demonstrated to date.

SGA-WZ: A New Strapdown Airborne Gravimeter

Directory of Open Access Journals (Sweden)

Kaidong Zhang

2012-07-01

Full Text Available Inertial navigation systems and gravimeters are now routinely used to map the regional gravitational quantities from an aircraft with mGal accuracy and a spatial resolution of a few kilometers. However, airborne gravimeter of this kind is limited by the inaccuracy of the inertial sensor performance, the integrated navigation technique and the kinematic acceleration determination. As the GPS technique developed, the vehicle acceleration determination is no longer the limiting factor in airborne gravity due to the cancellation of the common mode acceleration in differential mode. A new airborne gravimeter taking full advantage of the inertial navigation system is described with improved mechanical design, high precision time synchronization, better thermal control and optimized sensor modeling. Apart from the general usage, the Global Positioning System (GPS after differentiation is integrated to the inertial navigation system which provides not only more precise altitude information along with the navigation aiding, but also an effective way to calculate the vehicle acceleration. Design description and test results on the performance of the gyroscopes and accelerations will be emphasized. Analysis and discussion of the airborne field test results are also given.

SGA-WZ: A New Strapdown Airborne Gravimeter

DEFF Research Database (Denmark)

Huang, Yangming; Olesen, Arne Vestergaard; Wu, Meiping

2012-01-01

Inertial navigation systems and gravimeters are now routinely used to map the regional gravitational quantities from an aircraft with mGal accuracy and a spatial resolution of a few kilometers. However, airborne gravimeter of this kind is limited by the inaccuracy of the inertial sensor performance......, the integrated navigation technique and the kinematic acceleration determination. As the GPS technique developed, the vehicle acceleration determination is no longer the limiting factor in airborne gravity due to the cancellation of the common mode acceleration in differential mode. A new airborne gravimeter...... and discussion of the airborne field test results are also given....

Sensor and computing resource management for a small satellite

Science.gov (United States)

Bhatia, Abhilasha; Goehner, Kyle; Sand, John; Straub, Jeremy; Mohammad, Atif; Korvald, Christoffer; Nervold, Anders Kose

A small satellite in a low-Earth orbit (e.g., approximately a 300 to 400 km altitude) has an orbital velocity in the range of 8.5 km/s and completes an orbit approximately every 90 minutes. For a satellite with minimal attitude control, this presents a significant challenge in obtaining multiple images of a target region. Presuming an inclination in the range of 50 to 65 degrees, a limited number of opportunities to image a given target or communicate with a given ground station are available, over the course of a 24-hour period. For imaging needs (where solar illumination is required), the number of opportunities is further reduced. Given these short windows of opportunity for imaging, data transfer, and sending commands, scheduling must be optimized. In addition to the high-level scheduling performed for spacecraft operations, payload-level scheduling is also required. The mission requires that images be post-processed to maximize spatial resolution and minimize data transfer (through removing overlapping regions). The payload unit includes GPS and inertial measurement unit (IMU) hardware to aid in image alignment for the aforementioned. The payload scheduler must, thus, split its energy and computing-cycle budgets between determining an imaging sequence (required to capture the highly-overlapping data required for super-resolution and adjacent areas required for mosaicking), processing the imagery (to perform the super-resolution and mosaicking) and preparing the data for transmission (compressing it, etc.). This paper presents an approach for satellite control, scheduling and operations that allows the cameras, GPS and IMU to be used in conjunction to acquire higher-resolution imagery of a target region.

Concept of AHRS Algorithm Designed for Platform Independent Imu Attitude Alignment

Science.gov (United States)

Tomaszewski, Dariusz; Rapiński, Jacek; Pelc-Mieczkowska, Renata

2017-12-01

Nowadays, along with the advancement of technology one can notice the rapid development of various types of navigation systems. So far the most popular satellite navigation, is now supported by positioning results calculated with use of other measurement system. The method and manner of integration will depend directly on the destination of system being developed. To increase the frequency of readings and improve the operation of outdoor navigation systems, one will support satellite navigation systems (GPS, GLONASS ect.) with inertial navigation. Such method of navigation consists of several steps. The first stage is the determination of initial orientation of inertial measurement unit, called INS alignment. During this process, on the basis of acceleration and the angular velocity readings, values of Euler angles (pitch, roll, yaw) are calculated allowing for unambiguous orientation of the sensor coordinate system relative to external coordinate system. The following study presents the concept of AHRS (Attitude and heading reference system) algorithm, allowing to define the Euler angles.The study were conducted with the use of readings from low-cost MEMS cell phone sensors. Subsequently the results of the study were analyzed to determine the accuracy of featured algorithm. On the basis of performed experiments the legitimacy of developed algorithm was stated.

Proof of concept for turbulence measurements with the RPAS SUMO during the BLLAST campaign

Science.gov (United States)

Båserud, Line; Reuder, Joachim; Jonassen, Marius O.; Kral, Stephan T.; Paskyabi, Mostafa B.; Lothon, Marie

2016-10-01

The micro-RPAS (remotely piloted aircraft system) SUMO (Small Unmanned Meteorological Observer) equipped with a five-hole-probe (5HP) system for turbulent flow measurements was operated in 49 flight missions during the BLLAST (Boundary-Layer Late Afternoon and Sunset Turbulence) field campaign in 2011. Based on data sets from these flights, we investigate the potential and limitations of airborne velocity variance and TKE (turbulent kinetic energy) estimations by an RPAS with a take-off weight below 1 kg. The integration of the turbulence probe in the SUMO system was still in an early prototype stage during this campaign, and therefore extensive post-processing of the data was required. In order to be able to calculate the three-dimensional wind vector, flow probe measurements were first synchronized with the autopilot's attitude and velocity data. Clearly visible oscillations were detected in the resulting vertical velocity, w, even after correcting for the aircraft motion. The oscillations in w were identified as the result of an internal time shift between the inertial measurement unit (IMU) and the GPS sensors, leading to insufficient motion correction, especially for the vertical wind component, causing large values of σw. Shifting the IMU 1-1.5 s forward in time with respect to the GPS yields a minimum for σw and maximum covariance between the IMU pitch angle and the GPS climb angle. The SUMO data show a good agreement to sonic anemometer data from a 60 m tower for σu, but show slightly higher values for σv and σw. Vertical TKE profiles, obtained from consecutive flight legs at different altitudes, show reasonable results, both with respect to the overall TKE level and the temporal variation. A thorough discussion of the methods used and the identified uncertainties and limitations of the system for turbulence measurements is included and should help the developers and users of other systems with similar problems.

Self-directed arm therapy at home after stroke with a sensor-based virtual reality training system.

Science.gov (United States)

Wittmann, Frieder; Held, Jeremia P; Lambercy, Olivier; Starkey, Michelle L; Curt, Armin; Höver, Raphael; Gassert, Roger; Luft, Andreas R; Gonzenbach, Roman R

2016-08-11

The effect of rehabilitative training after stroke is dose-dependent. Out-patient rehabilitation training is often limited by transport logistics, financial resources and a lack of motivation/compliance. We studied the feasibility of an unsupervised arm therapy for self-directed rehabilitation therapy in patients' homes. An open-label, single group study involving eleven patients with hemiparesis due to stroke (27 ± 31.5 months post-stroke) was conducted. The patients trained with an inertial measurement unit (IMU)-based virtual reality system (ArmeoSenso) in their homes for six weeks. The self-selected dose of training with ArmeoSenso was the principal outcome measure whereas the Fugl-Meyer Assessment of the upper extremity (FMA-UE), the Wolf Motor Function Test (WMFT) and IMU-derived kinematic metrics were used to assess arm function, training intensity and trunk movement. Repeated measures one-way ANOVAs were used to assess differences in training duration and clinical scores over time. All subjects were able to use the system independently in their homes and no safety issues were reported. Patients trained on 26.5 ± 11.5 days out of 42 days for a duration of 137 ± 120 min per week. The weekly training duration did not change over the course of six weeks (p = 0.146). The arm function of these patients improved significantly by 4.1 points (p = 0.003) in the FMA-UE. Changes in the WMFT were not significant (p = 0.552). ArmeoSenso based metrics showed an improvement in arm function, a high number of reaching movements (387 per session), and minimal compensatory movements of the trunk while training. Self-directed home therapy with an IMU-based home therapy system is safe and can provide a high dose of rehabilitative therapy. The assessments integrated into the system allow daily therapy monitoring, difficulty adaptation and detection of maladaptive motor patterns such as trunk movements during reaching. Unique identifier: NCT02098135 .

Time-frequency analysis of human motion during rhythmic exercises.

Science.gov (United States)

Omkar, S N; Vyas, Khushi; Vikranth, H N

2011-01-01

Biomechanical signals due to human movements during exercise are represented in time-frequency domain using Wigner Distribution Function (WDF). Analysis based on WDF reveals instantaneous spectral and power changes during a rhythmic exercise. Investigations were carried out on 11 healthy subjects who performed 5 cycles of sun salutation, with a body-mounted Inertial Measurement Unit (IMU) as a motion sensor. Variance of Instantaneous Frequency (I.F) and Instantaneous Power (I.P) for performance analysis of the subject is estimated using one-way ANOVA model. Results reveal that joint Time-Frequency analysis of biomechanical signals during motion facilitates a better understanding of grace and consistency during rhythmic exercise.

Orion Exploration Flight Test-1 Post-Flight Navigation Performance Assessment Relative to the Best Estimated Trajectory

Science.gov (United States)

Gay, Robert S.; Holt, Greg N.; Zanetti, Renato

2016-01-01

This paper details the post-flight navigation performance assessment of the Orion Exploration Flight Test-1 (EFT-1). Results of each flight phase are presented: Ground Align, Ascent, Orbit, and Entry Descent and Landing. This study examines the on-board Kalman Filter uncertainty along with state deviations relative to the Best Estimated Trajectory (BET). Overall the results show that the Orion Navigation System performed as well or better than expected. Specifically, the Global Positioning System (GPS) measurement availability was significantly better than anticipated at high altitudes. In addition, attitude estimation via processing GPS measurements along with Inertial Measurement Unit (IMU) data performed very well and maintained good attitude throughout the mission.

Towards High-Definition 3D Urban Mapping: Road Feature-Based Registration of Mobile Mapping Systems and Aerial Imagery

Directory of Open Access Journals (Sweden)

Mahdi Javanmardi

2017-09-01

Full Text Available Various applications have utilized a mobile mapping system (MMS as the main 3D urban remote sensing platform. However, the accuracy and precision of the three-dimensional data acquired by an MMS is highly dependent on the performance of the vehicle’s self-localization, which is generally performed by high-end global navigation satellite system (GNSS/inertial measurement unit (IMU integration. However, GNSS/IMU positioning quality degrades significantly in dense urban areas with high-rise buildings, which block and reflect the satellite signals. Traditional landmark updating methods, which improve MMS accuracy by measuring ground control points (GCPs and manually identifying those points in the data, are both labor-intensive and time-consuming. In this paper, we propose a novel and comprehensive framework for automatically georeferencing MMS data by capitalizing on road features extracted from high-resolution aerial surveillance data. The proposed framework has three key steps: (1 extracting road features from the MMS and aerial data; (2 obtaining Gaussian mixture models from the extracted aerial road features; and (3 performing registration of the MMS data to the aerial map using a dynamic sliding window and the normal distribution transform (NDT. The accuracy of the proposed framework is verified using field data, demonstrating that it is a reliable solution for high-precision urban mapping.

Low-Cost Monitoring System of Sensors for Evaluating Dynamic Solicitations of Semitrailer Structure

Directory of Open Access Journals (Sweden)

Pablo Luque

2016-01-01

Full Text Available Analysis of the fatigue life of a semitrailer structure necessitates identification of the loads and dynamic solicitations in the structure. These forces can be introduced in computer simulation software (multibody + finite element for analysing the response of different design solutions to them. These numerical models must be validated and some parameters need to be measured directly in a field test with real vehicles under various driving conditions. In this study, a low-cost monitoring system is developed for application to a real fleet of semitrailers. According to the definition of the numerical model, the guidance of a virtual vehicle is defined by the three-dimensional kinematics of the kingpin. For characterisation of these movements, a monitoring system having a low-cost inertial measurement unit (IMU and global positioning system (GPS antennas is developed with different configurations to enable analysis of the best cost-benefit (result accuracy solution, and an extended Kalman filter (EKF that characterises the kinematic guidance of the kingpin is proposed. A semitrailer was equipped with the experimental low-cost monitoring system and high-precision sensors (IMU, GPS in order to validate the results obtained by the experimental low-cost monitoring system and the inertial-extended Kalman filter developed. The validated system has applicability in the low-cost monitoring of a fleet of real vehicles.

A self-calibration method in single-axis rotational inertial navigation system with rotating mechanism

Science.gov (United States)

Chen, Yuanpei; Wang, Lingcao; Li, Kui

2017-10-01

Rotary inertial navigation modulation mechanism can greatly improve the inertial navigation system (INS) accuracy through the rotation. Based on the single-axis rotational inertial navigation system (RINS), a self-calibration method is put forward. The whole system is applied with the rotation modulation technique so that whole inertial measurement unit (IMU) of system can rotate around the motor shaft without any external input. In the process of modulation, some important errors can be decoupled. Coupled with the initial position information and attitude information of the system as the reference, the velocity errors and attitude errors in the rotation are used as measurement to perform Kalman filtering to estimate part of important errors of the system after which the errors can be compensated into the system. The simulation results show that the method can complete the self-calibration of the single-axis RINS in 15 minutes and estimate gyro drifts of three-axis, the installation error angle of the IMU and the scale factor error of the gyro on z-axis. The calibration accuracy of optic gyro drifts could be about 0.003°/h (1σ) as well as the scale factor error could be about 1 parts per million (1σ). The errors estimate reaches the system requirements which can effectively improve the longtime navigation accuracy of the vehicle or the boat.

Atrial Fibrillation Detection via Accelerometer and Gyroscope of a Smartphone.

Science.gov (United States)

Lahdenoja, Olli; Hurnanen, Tero; Iftikhar, Zuhair; Nieminen, Sami; Knuutila, Timo; Saraste, Antti; Kiviniemi, Tuomas; Vasankari, Tuija; Airaksinen, Juhani; Pankaala, Mikko; Koivisto, Tero

2018-01-01

We present a smartphone-only solution for the detection of atrial fibrillation (AFib), which utilizes the built-in accelerometer and gyroscope sensors [inertial measurement unit, (IMU)] in the detection. Depending on the patient's situation, it is possible to use the developed smartphone application either regularly or occasionally for making a measurement of the subject. The smartphone is placed on the chest of the patient who is adviced to lay down and perform a noninvasive recording, while no external sensors are needed. After that, the application determines whether the patient suffers from AFib or not. The presented method has high potential to detect paroxysmal ("silent") AFib from large masses. In this paper, we present the preprocessing, feature extraction, feature analysis, and classification results of the envisioned AFib detection system based on clinical data acquired with a standard mobile phone equipped with Google Android OS. Test data was gathered from 16 AFib patients (validated against ECG), as well as a control group of 23 healthy individuals with no diagnosed heart diseases. We obtained an accuracy of 97.4% in AFib versus healthy classification (a sensitivity of 93.8% and a specificity of 100%). Due to the wide availability of smart devices/sensors with embedded IMU, the proposed methods could potentially also scale to other domains such as embedded body-sensor networks.

Quadrotor helicopter for surface hydrological measurements

Science.gov (United States)

Pagano, C.; Tauro, F.; Porfiri, M.; Grimaldi, S.

2013-12-01

Surface hydrological measurements are typically performed through user-assisted and intrusive field methodologies which can be inadequate to monitor remote and extended areas. In this poster, we present the design and development of a quadrotor helicopter equipped with digital acquisition system and image calibration units for surface flow measurements. This custom-built aerial vehicle is engineered to be lightweight, low-cost, highly customizable, and stable to guarantee optimal image quality. Quadricopter stability guarantees minimal vibrations during image acquisition and, therefore, improved accuracy in flow velocity estimation through large scale particle image velocimetry algorithms or particle tracking procedures. Stability during the vehicle pitching and rolling is achieved by adopting large arm span and high-wing configurations. Further, the vehicle framework is composed of lightweight aluminum and durable carbon fiber for optimal resilience. The open source Ardupilot microcontroller is used for remote control of the quadricopter. The microcontroller includes an inertial measurement unit (IMU) equipped with accelerometers and gyroscopes for stable flight through feedback control. The vehicle is powered by a 3 cell (11.1V) 3000 mAh Lithium-polymer battery. Electronic equipment and wiring are hosted into the hollow arms and on several carbon fiber platforms in the waterproof fuselage. Four 35A high-torque motors are supported at the far end of each arm with 10 × 4.7 inch propellers. Energy dissipation during landing is accomplished by four pivoting legs that, through the use of shock absorbers, prevent the impact energy from affecting the frame thus causing significant damage. The data capturing system consists of a GoPro Hero3 camera and in-house built camera gimbal and shock absorber damping device. The camera gimbal, hosted below the vehicle fuselage, is engineered to maintain the orthogonality of the camera axis with respect to the water surface by

DIRECT GEOREFERENCING : A NEW STANDARD IN PHOTOGRAMMETRY FOR HIGH ACCURACY MAPPING

Directory of Open Access Journals (Sweden)

A. Rizaldy

2012-07-01

Full Text Available Direct georeferencing is a new method in photogrammetry, especially in the digital camera era. Theoretically, this method does not require ground control points (GCP and the Aerial Triangulation (AT, to process aerial photography into ground coordinates. Compared with the old method, this method has three main advantages: faster data processing, simple workflow and less expensive project, at the same accuracy. Direct georeferencing using two devices, GPS and IMU. GPS recording the camera coordinates (X, Y, Z, and IMU recording the camera orientation (omega, phi, kappa. Both parameters merged into Exterior Orientation (EO parameter. This parameters required for next steps in the photogrammetric projects, such as stereocompilation, DSM generation, orthorectification and mosaic. Accuracy of this method was tested on topographic map project in Medan, Indonesia. Large-format digital camera Ultracam X from Vexcel is used, while the GPS / IMU is IGI AeroControl. 19 Independent Check Point (ICP were used to determine the accuracy. Horizontal accuracy is 0.356 meters and vertical accuracy is 0.483 meters. Data with this accuracy can be used for 1:2.500 map scale project.

Low-cost wave characterization modules for oil spill response

Directory of Open Access Journals (Sweden)

E.D. Skinner

2018-06-01

Full Text Available Marine oil spills can be remediated by mechanical skimmers in calm waters, but performance degrades with increased wave height. We have developed and demonstrated a system that quantifies local wave characteristics with an uncertainty of four inches of heave. Our system is intended for the measurement of wave characteristics during oil spill recovery. It conveys this information to coordinators and responders in real time via WiFi and remote reporting through a satellite network. This information will allow for enhanced situational awareness during an oil spill response, assisting stakeholders and optimizing mechanical skimming operations. Our wave characterization module (WCM uses accelerometer outputs from a very small inertial measurement unit (IMU to generate wave statistics and calculate wave characteristics. It is configured such that a WCM can either be attached to a skimmer float or incorporated into a microbuoy. Wave height and period are transmitted via WiFi and/or a satellite-enabled mesh-grid network to a cloud-hosted geographic information system (GIS. Here, we discuss the bare-bones sensors-plus-algorithm approach we developed by using spring-mass systems to approximate the wave height and period regime of interest. We then describe open water tests carried out using that development system both mounted to a weir skimmer mockup and packaged in a microbuoy. Finally, we present controlled tests in the wave tank at Ohmsett, the National Oil Spill Response Test Facility in New Jersey, with the WCMs communicating the wave characteristics via WiFi to tankside laptops and via satellite to the cloud-based GIS. Snapshot determinations of wave height calculated using the scalar magnitude of the three-axis accelerometer in the IMU were within four inches of the benchmark wave measurement system at Ohmsett. Keywords: Oil spill, Wave characterization module, Inertial measurement unit, Microbuoy

Low Cost Integrated Navigation System for Unmanned Vessel

Directory of Open Access Journals (Sweden)

Yang Changsong

2017-11-01

Full Text Available Large errors of low-cost MEMS inertial measurement unit (MIMU lead to huge navigation errors, even wrong navigation information. An integrated navigation system for unmanned vessel is proposed. It consists of a low-cost MIMU and Doppler velocity sonar (DVS. This paper presents an integrated navigation method, to improve the performance of navigation system. The integrated navigation system is tested using simulation and semi-physical simulation experiments, whose results show that attitude, velocity and position accuracy has improved awfully, giving exactly accurate navigation results. By means of the combination of low-cost MIMU and DVS, the proposed system is able to overcome fast drift problems of the low cost IMU.

Field Programmable Gate Array (FPGA Respiratory Monitoring System Using a Flow Microsensor and an Accelerometer

Directory of Open Access Journals (Sweden)

Mellal Idir

2017-04-01

Full Text Available This paper describes a non-invasive system for respiratory monitoring using a Micro Electro Mechanical Systems (MEMS flow sensor and an IMU (Inertial Measurement Unit accelerometer. The designed system is intended to be wearable and used in a hospital or at home to assist people with respiratory disorders. To ensure the accuracy of our system, we proposed a calibration method based on ANN (Artificial Neural Network to compensate the temperature drift of the silicon flow sensor. The sigmoid activation functions used in the ANN model were computed with the CORDIC (COordinate Rotation DIgital Computer algorithm. This algorithm was also used to estimate the tilt angle in body position. The design was implemented on reconfigurable platform FPGA.

Novel Smart Glove Technology as a Biomechanical Monitoring Tool

Directory of Open Access Journals (Sweden)

Brendan O’FLYNN

2015-10-01

Full Text Available Developments in Virtual Reality (VR technology and its overall market have been occurring since the 1960s when Ivan Sutherland created the world’s first tracked head-mounted display (HMD – a goggle type head gear. In society today, consumers are expecting a more immersive experience and associated tools to bridge the cyber-physical divide. This paper presents the development of a next generation smart glove microsystem to facilitate Human Computer Interaction through the integration of sensors, processors and wireless technology. The objective of the glove is to measure the range of hand joint movements, in real time and empirically in a quantitative manner. This includes accurate measurement of flexion, extension, adduction and abduction of the metacarpophalangeal (MCP, Proximal interphalangeal (PIP and Distal interphalangeal (DIP joints of the fingers and thumb in degrees, together with thumb-index web space movement. This system enables full real-time monitoring of complex hand movements. Commercially available gloves are not fitted with sufficient sensors for full data capture, and require calibration for each glove wearer. Unlike these current state-of-the-art data gloves, the UU / Tyndall Inertial Measurement Unit (IMU glove uses a combination of novel stretchable substrate material and 9 degree of freedom (DOF inertial sensors in conjunction with complex data analytics to detect joint movement. Our novel IMU data glove requires minimal calibration and is therefore particularly suited to multiple application domains such as Human Computer interfacing, Virtual reality, the healthcare environment..

Using Arm and Hand Gestures to Command Robots during Stealth Operations

Science.gov (United States)

Stoica, Adrian; Assad, Chris; Wolf, Michael; You, Ki Sung; Pavone, Marco; Huntsberger, Terry; Iwashita, Yumi

2012-01-01

Command of support robots by the warfighter requires intuitive interfaces to quickly communicate high degree-of-freedom (DOF) information while leaving the hands unencumbered. Stealth operations rule out voice commands and vision-based gesture interpretation techniques, as they often entail silent operations at night or in other low visibility conditions. Targeted at using bio-signal inputs to set navigation and manipulation goals for the robot (say, simply by pointing), we developed a system based on an electromyography (EMG) "BioSleeve", a high density sensor array for robust, practical signal collection from forearm muscles. The EMG sensor array data is fused with inertial measurement unit (IMU) data. This paper describes the BioSleeve system and presents initial results of decoding robot commands from the EMG and IMU data using a BioSleeve prototype with up to sixteen bipolar surface EMG sensors. The BioSleeve is demonstrated on the recognition of static hand positions (e.g. palm facing front, fingers upwards) and on dynamic gestures (e.g. hand wave). In preliminary experiments, over 90% correct recognition was achieved on five static and nine dynamic gestures. We use the BioSleeve to control a team of five LANdroid robots in individual and group/squad behaviors. We define a gesture composition mechanism that allows the specification of complex robot behaviors with only a small vocabulary of gestures/commands, and we illustrate it with a set of complex orders.

The Effects of Lever Arm (Instrument Offset) Error on GRAV-D Airborne Gravity Data

Science.gov (United States)

Johnson, J. A.; Youngman, M.; Damiani, T.

2017-12-01

High quality airborne gravity collection with a 2-axis, stabilized platform gravity instrument, such as with a Micro-g LaCoste Turnkey Airborne Gravity System (TAGS), is dependent on the aircraft's ability to maintain "straight and level" flight. However, during flight there is constant rotation about the aircraft's center of gravity. Standard practice is to install the scientific equipment close to the aircraft's estimated center of gravity to minimize the relative rotations with aircraft motion. However, there remain small offsets between the instruments. These distance offsets, the lever arm, are used to define the rigid-body, spatial relationship between the IMU, GPS antenna, and airborne gravimeter within the aircraft body frame. The Gravity for the Redefinition of the American Vertical Datum (GRAV-D) project, which is collecting airborne gravity data across the U.S., uses a commercial software package for coupled IMU-GNSS aircraft positioning. This software incorporates a lever arm correction to calculate a precise position for the airborne gravimeter. The positioning software must do a coordinate transformation to relate each epoch of the coupled GNSS-IMU derived position to the position of the gravimeter within the constantly-rotating aircraft. This transformation requires three inputs: accurate IMU-measured aircraft rotations, GNSS positions, and lever arm distances between instruments. Previous studies show that correcting for the lever arm distances improves gravity results, but no sensitivity tests have been done to investigate how error in the lever arm distances affects the final airborne gravity products. This research investigates the effects of lever arm measurement error on airborne gravity data. GRAV-D lever arms are nominally measured to the cm-level using surveying equipment. "Truth" data sets will be created by processing GRAV-D flight lines with both relatively small lever arms and large lever arms. Then negative and positive incremental

The Development of an IMU Integrated Clothes for Postural Monitoring Using Conductive Yarn and Interconnecting Technology.

Science.gov (United States)

Kang, Sung-Won; Choi, Hyeob; Park, Hyung-Il; Choi, Byoung-Gun; Im, Hyobin; Shin, Dongjun; Jung, Young-Giu; Lee, Jun-Young; Park, Hong-Won; Park, Sukyung; Roh, Jung-Sim

2017-11-07

Spinal disease is a common yet important condition that occurs because of inappropriate posture. Prevention could be achieved by continuous posture monitoring, but most measurement systems cannot be used in daily life due to factors such as burdensome wires and large sensing modules. To improve upon these weaknesses, we developed comfortable "smart wear" for posture measurement using conductive yarn for circuit patterning and a flexible printed circuit board (FPCB) for interconnections. The conductive yarn was made by twisting polyester yarn and metal filaments, and the resistance per unit length was about 0.05 Ω/cm. An embroidered circuit was made using the conductive yarn, which showed increased yield strength and uniform electrical resistance per unit length. Circuit networks of sensors and FPCBs for interconnection were integrated into clothes using a computer numerical control (CNC) embroidery process. The system was calibrated and verified by comparing the values measured by the smart wear with those measured by a motion capture camera system. Six subjects performed fixed movements and free computer work, and, with this system, we were able to measure the anterior/posterior direction tilt angle with an error of less than 4°. The smart wear does not have excessive wires, and its structure will be optimized for better posture estimation in a later study.

Unscented Kalman filter for SINS alignment

Institute of Scientific and Technical Information of China (English)

Zhou Zhanxin; Gao Yanan; Chen Jiabin

2007-01-01

In order to improve the filter accuracy for the nonlinear error model of strapdown inertial navigation system (SINS) alignment, Unscented Kalman Filter (UKF) is presented for simulation with stationary base and moving base of SINS alignment.Simulation results show the superior performance of this approach when compared with classical suboptimal techniques such as extended Kalman filter in cases of large initial misalignment.The UKF has good performance in case of small initial misalignment.

The Development of an IMU Integrated Clothes for Postural Monitoring Using Conductive Yarn and Interconnecting Technology

Directory of Open Access Journals (Sweden)

Sung-Won Kang

2017-11-01

Full Text Available Spinal disease is a common yet important condition that occurs because of inappropriate posture. Prevention could be achieved by continuous posture monitoring, but most measurement systems cannot be used in daily life due to factors such as burdensome wires and large sensing modules. To improve upon these weaknesses, we developed comfortable “smart wear” for posture measurement using conductive yarn for circuit patterning and a flexible printed circuit board (FPCB for interconnections. The conductive yarn was made by twisting polyester yarn and metal filaments, and the resistance per unit length was about 0.05 Ω/cm. An embroidered circuit was made using the conductive yarn, which showed increased yield strength and uniform electrical resistance per unit length. Circuit networks of sensors and FPCBs for interconnection were integrated into clothes using a computer numerical control (CNC embroidery process. The system was calibrated and verified by comparing the values measured by the smart wear with those measured by a motion capture camera system. Six subjects performed fixed movements and free computer work, and, with this system, we were able to measure the anterior/posterior direction tilt angle with an error of less than 4°. The smart wear does not have excessive wires, and its structure will be optimized for better posture estimation in a later study.

An Enhanced Intelligent Handheld Instrument with Visual Servo Control for 2-DOF Hand Motion Error Compensation

Directory of Open Access Journals (Sweden)

Yan Naing Aye

2013-10-01

Full Text Available The intelligent handheld instrument, ITrem2, enhances manual positioning accuracy by cancelling erroneous hand movements and, at the same time, provides automatic micromanipulation functions. Visual data is acquired from a high speed monovision camera attached to the optical surgical microscope and acceleration measurements are acquired from the inertial measurement unit (IMU on board ITrem2. Tremor estimation and canceling is implemented via Band-limited Multiple Fourier Linear Combiner (BMFLC filter. The piezoelectric actuated micromanipulator in ITrem2 generates the 3D motion to compensate erroneous hand motion. Preliminary bench-top 2-DOF experiments have been conducted. The error motions simulated by a motion stage is reduced by 67% for multiple frequency oscillatory motions and 56.16% for pre-conditioned recorded physiological tremor.

PseKRAAC: a flexible web server for generating pseudo K-tuple reduced amino acids composition.

Science.gov (United States)

Zuo, Yongchun; Li, Yuan; Chen, Yingli; Li, Guangpeng; Yan, Zhenhe; Yang, Lei

2017-01-01

The reduced amino acids perform powerful ability for both simplifying protein complexity and identifying functional conserved regions. However, dealing with different protein problems may need different kinds of cluster methods. Encouraged by the success of pseudo-amino acid composition algorithm, we developed a freely available web server, called PseKRAAC (the pseudo K-tuple reduced amino acids composition). By implementing reduced amino acid alphabets, the protein complexity can be significantly simplified, which leads to decrease chance of overfitting, lower computational handicap and reduce information redundancy. PseKRAAC delivers more capability for protein research by incorporating three crucial parameters that describes protein composition. Users can easily generate many different modes of PseKRAAC tailored to their needs by selecting various reduced amino acids alphabets and other characteristic parameters. It is anticipated that the PseKRAAC web server will become a very useful tool in computational proteomics and protein sequence analysis. Freely available on the web at http://bigdata.imu.edu.cn/psekraac CONTACTS: yczuo@imu.edu.cn or imu.hema@foxmail.com or yanglei_hmu@163.comSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

An Online Solution of LiDAR Scan Matching Aided Inertial Navigation System for Indoor Mobile Mapping

Directory of Open Access Journals (Sweden)

Xiaoji Niu

2017-01-01

Full Text Available Multisensors (LiDAR/IMU/CAMERA integrated Simultaneous Location and Mapping (SLAM technology for navigation and mobile mapping in a GNSS-denied environment, such as indoor areas, dense forests, or urban canyons, becomes a promising solution. An online (real-time version of such system can extremely extend its applications, especially for indoor mobile mapping. However, the real-time response issue of multisensors is a big challenge for an online SLAM system, due to the different sampling frequencies and processing time of different algorithms. In this paper, an online Extended Kalman Filter (EKF integrated algorithm of LiDAR scan matching and IMU mechanization for Unmanned Ground Vehicle (UGV indoor navigation system is introduced. Since LiDAR scan matching is considerably more time consuming than the IMU mechanism, the real-time synchronous issue is solved via a one-step-error-state-transition method in EKF. Stationary and dynamic field tests had been performed using a UGV platform along typical corridor of office building. Compared to the traditional sequential postprocessed EKF algorithm, the proposed method can significantly mitigate the time delay of navigation outputs under the premise of guaranteeing the positioning accuracy, which can be used as an online navigation solution for indoor mobile mapping.

Wearable Inertial Sensor Systems for Lower Limb Exercise Detection and Evaluation: A Systematic Review.

Science.gov (United States)

O'Reilly, Martin; Caulfield, Brian; Ward, Tomas; Johnston, William; Doherty, Cailbhe

2018-05-01

Analysis of lower limb exercises is traditionally completed with four distinct methods: (1) 3D motion capture; (2) depth-camera-based systems; (3) visual analysis from a qualified exercise professional; and (4) self-assessment. Each method is associated with a number of limitations. The aim of this systematic review is to synthesise and evaluate studies which have investigated the capacity for inertial measurement unit (IMU) technologies to assess movement quality in lower limb exercises. A systematic review of studies identified through the databases of PubMed, ScienceDirect and Scopus was conducted. Articles written in English and published in the last 10 years which investigated an IMU system for the analysis of repetition-based targeted lower limb exercises were included. The quality of included studies was measured using an adapted version of the STROBE assessment criteria for cross-sectional studies. The studies were categorised into three groupings: exercise detection, movement classification or measurement validation. Each study was then qualitatively summarised. From the 2452 articles that were identified with the search strategies, 47 papers are included in this review. Twenty-six of the 47 included studies were deemed as being of high quality. Wearable inertial sensor systems for analysing lower limb exercises is a rapidly growing field of research. Research over the past 10 years has predominantly focused on validating measurements that the systems produce and classifying users' exercise quality. There have been very few user evaluation studies and no clinical trials in this field to date.

Motor Function Evaluation of Hemiplegic Upper-Extremities Using Data Fusion from Wearable Inertial and Surface EMG Sensors

Directory of Open Access Journals (Sweden)

Yanran Li

2017-03-01

Full Text Available Quantitative evaluation of motor function is of great demand for monitoring clinical outcome of applied interventions and further guiding the establishment of therapeutic protocol. This study proposes a novel framework for evaluating upper limb motor function based on data fusion from inertial measurement units (IMUs and surface electromyography (EMG sensors. With wearable sensors worn on the tested upper limbs, subjects were asked to perform eleven straightforward, specifically designed canonical upper-limb functional tasks. A series of machine learning algorithms were applied to the recorded motion data to produce evaluation indicators, which is able to reflect the level of upper-limb motor function abnormality. Sixteen healthy subjects and eighteen stroke subjects with substantial hemiparesis were recruited in the experiment. The combined IMU and EMG data yielded superior performance over the IMU data alone and the EMG data alone, in terms of decreased normal data variation rate (NDVR and improved determination coefficient (DC from a regression analysis between the derived indicator and routine clinical assessment score. Three common unsupervised learning algorithms achieved comparable performance with NDVR around 10% and strong DC around 0.85. By contrast, the use of a supervised algorithm was able to dramatically decrease the NDVR to 6.55%. With the proposed framework, all the produced indicators demonstrated high agreement with the routine clinical assessment scale, indicating their capability of assessing upper-limb motor functions. This study offers a feasible solution to motor function assessment in an objective and quantitative manner, especially suitable for home and community use.

Hand Pose Estimation by Fusion of Inertial and Magnetic Sensing Aided by a Permanent Magnet.

Science.gov (United States)

Kortier, Henk G; Antonsson, Jacob; Schepers, H Martin; Gustafsson, Fredrik; Veltink, Peter H

2015-09-01

Tracking human body motions using inertial sensors has become a well-accepted method in ambulatory applications since the subject is not confined to a lab-bounded volume. However, a major drawback is the inability to estimate relative body positions over time because inertial sensor information only allows position tracking through strapdown integration, but does not provide any information about relative positions. In addition, strapdown integration inherently results in drift of the estimated position over time. We propose a novel method in which a permanent magnet combined with 3-D magnetometers and 3-D inertial sensors are used to estimate the global trunk orientation and relative pose of the hand with respect to the trunk. An Extended Kalman Filter is presented to fuse estimates obtained from inertial sensors with magnetic updates such that the position and orientation between the human hand and trunk as well as the global trunk orientation can be estimated robustly. This has been demonstrated in multiple experiments in which various hand tasks were performed. The most complex task in which simultaneous movements of both trunk and hand were performed resulted in an average rms position difference with an optical reference system of 19.7±2.2 mm whereas the relative trunk-hand and global trunk orientation error was 2.3±0.9 and 8.6±8.7 deg respectively.

Inertial Pocket Navigation System: Unaided 3D Positioning

Directory of Open Access Journals (Sweden)

Estefania Munoz Diaz

2015-04-01

Full Text Available Inertial navigation systems use dead-reckoning to estimate the pedestrian’s position. There are two types of pedestrian dead-reckoning, the strapdown algorithm and the step-and-heading approach. Unlike the strapdown algorithm, which consists of the double integration of the three orthogonal accelerometer readings, the step-and-heading approach lacks the vertical displacement estimation. We propose the first step-and-heading approach based on unaided inertial data solving 3D positioning. We present a step detector for steps up and down and a novel vertical displacement estimator. Our navigation system uses the sensor introduced in the front pocket of the trousers, a likely location of a smartphone. The proposed algorithms are based on the opening angle of the leg or pitch angle. We analyzed our step detector and compared it with the state-of-the-art, as well as our already proposed step length estimator. Lastly, we assessed our vertical displacement estimator in a real-world scenario. We found that our algorithms outperform the literature step and heading algorithms and solve 3D positioning using unaided inertial data. Additionally, we found that with the pitch angle, five activities are distinguishable: standing, sitting, walking, walking up stairs and walking down stairs. This information complements the pedestrian location and is of interest for applications, such as elderly care.

Inertial Pocket Navigation System: Unaided 3D Positioning

Science.gov (United States)

Munoz Diaz, Estefania

2015-01-01

Inertial navigation systems use dead-reckoning to estimate the pedestrian's position. There are two types of pedestrian dead-reckoning, the strapdown algorithm and the step-and-heading approach. Unlike the strapdown algorithm, which consists of the double integration of the three orthogonal accelerometer readings, the step-and-heading approach lacks the vertical displacement estimation. We propose the first step-and-heading approach based on unaided inertial data solving 3D positioning. We present a step detector for steps up and down and a novel vertical displacement estimator. Our navigation system uses the sensor introduced in the front pocket of the trousers, a likely location of a smartphone. The proposed algorithms are based on the opening angle of the leg or pitch angle. We analyzed our step detector and compared it with the state-of-the-art, as well as our already proposed step length estimator. Lastly, we assessed our vertical displacement estimator in a real-world scenario. We found that our algorithms outperform the literature step and heading algorithms and solve 3D positioning using unaided inertial data. Additionally, we found that with the pitch angle, five activities are distinguishable: standing, sitting, walking, walking up stairs and walking down stairs. This information complements the pedestrian location and is of interest for applications, such as elderly care. PMID:25897501

Symposium Gyro Technology 1997

Energy Technology Data Exchange (ETDEWEB)

Sorg, H [ed.; Stuttgart Univ. (Germany). Inst. A fuer Mechanik

1997-10-01

This volume includes the twenty papers which were presented at the Symposium Gyro Technology 1997. The subjects that have been treated during the symposium were as follows: Performance and design of silicon micromachined gyro; improved rate gyroscope designs designated for fabrication by modern deep silicon etching; micromechanical vibratory rate gyroscopes fabricated in conventional CMOS; error modelling of silicon angular rate sensor; a capacitive accelerometer as an example for surface micromachined inertial sensors; initial production results of a new family of fiber optic gyroscopes; dual-axis multiplexed open loop fiber optic gyroscope; flattely supported vibratory gyro-sensor using a Trident-type tuning fork resonator; innovative mechanizations to optimize inertial sensors for high or low rate operations; design of a planar vibratory gyroscope using electrostatic actuation and electromanetic detection; fiber optic gyro based land navigation system; FOG AHRS and AHRS/GPS navigation system: the low cost solution; GPS/GLONASS/INS-navigation (GLOGINAV); small-sized integrated system of the sea mobile objects attitude and navigation; concepts for hybrid positioning; preliminary results from a large ring laser gyroscope for fundamental physics and geophysics; a `sense of balance` - AHRS with low-cost vibrating-gyroscopes for medical diagnostics; application of strapdown inertial systems of orientation and navigation in intrapipe moving diagnostic apparatus; investigation of a digital readout system for laser gyro; the use of angular rate multiple integrals as input signals for strapdown attitude algorithms. (AKF)

Research on Integration of Indoor and Outdoor Positioning in Professional Athletic Training

Directory of Open Access Journals (Sweden)

Yongqing Liu

2018-02-01

Full Text Available GNSS is widely used in professional athletic training as an outdoor location based services, and the indoor positioning technology has gradually flourished in the gymnasium. To keep up with the demand for athletic training in indoor and outdoor environment, integration of indoor and outdoor positioning technology can achieve a seamless indoor/outdoor position solution. The proposed method uses GPS/BEIDOU with IMU-MEMS technology for outdoor positioning and UWB with IMU-MEMS technology for indoor positioning to provide high precision positioning services. The experimental results show that the proposed method can achieve meter level position accuracy in outdoor environment and centimeter level position accuracy in indoor environment, it can provide precise and real-time positioning service for effective athletic training aid.

A highly accurate positioning and orientation system based on the usage of four-cluster fibre optic gyros

International Nuclear Information System (INIS)

Zhang, Xiaoyue; Lin, Zhili; Zhang, Chunxi

2013-01-01

A highly accurate positioning and orientation technique based on four-cluster fibre optic gyros (FOGs) is presented. The four-cluster FOG inertial measurement unit (IMU) comprises three low-precision FOGs, one static high-precision FOG and three accelerometers. To realize high-precision positioning and orientation, the static alignment (north-seeking) before vehicle manoeuvre was divided into a low-precision self-alignment phase and a high-precision north-seeking (online calibration) phase. The high-precision FOG measurement information was introduced to obtain high-precision azimuth alignment (north-seeking) result and achieve online calibration of the low-precision three-cluster FOG. The results of semi-physical simulation were presented to validate the availability and utility of the highly accurate positioning and orientation technique based on the four-cluster FOGs. (paper)

A Gyrocompass for Maritime Applications Based Upon Multivariable Control Theory

Directory of Open Access Journals (Sweden)

Olav Egeland

1984-10-01

Full Text Available A gyrocompass is designed using multivariable control theory. The compass can be implemented with an inertial platform or as a strap-down system. Measurement noise caused by vessel acceleration is modeled and feedforward is taken from vessel speed. Though the model is of order 9, it has only three unknown parameters of which one can be chosen a priori. Parameter estimation is discussed. For simulation of the compass, a non-linear surface vessel model with 6 degrees of freedom and wave excitation is used.

Nations United: The United Nations, the United States, and the Global Campaign Against Terrorism. A Curriculum Unit & Video for Secondary Schools.

Science.gov (United States)

Houlihan, Christina; McLeod, Shannon

This curriculum unit and 1-hour videotape are designed to help students understand the purpose and functions of the United Nations (UN) and explore the relationship between the United Nations and the United States. The UN's role in the global counterterrorism campaign serves as a case study for the unit. The students are asked to develop a basic…

A Quantitative Analysis of Dressing Dynamics for Robotic Dressing Assistance

Directory of Open Access Journals (Sweden)

Greg Chance

2017-05-01

Full Text Available Assistive robots have a great potential to address issues related to an aging population and an increased demand for caregiving. Successful deployment of robots working in close proximity with people requires consideration of both safety and human–robot interaction (HRI. One of the established activities of daily living where robots could play an assistive role is dressing. Using the correct force profile for robot control will be essential in this application of HRI requiring careful exploration of factors related to the user’s pose and the type of garments involved. In this paper, a Baxter robot was used to dress a jacket onto a mannequin and human participants considering several combinations of user pose and clothing type (base layers, while recording dynamic data from the robot, a load cell, and an IMU. We also report on suitability of these sensors for identifying dressing errors, e.g., fabric snagging. Data were analyzed by comparing the overlap of confidence intervals to determine sensitivity to dressing. We expand the analysis to include classification techniques such as decision tree and support vector machines using k-fold cross-validation. The 6-axis load cell successfully discriminated between clothing types with predictive model accuracies between 72 and 97%. Used independently, the IMU and Baxter sensors were insufficient to discriminate garment types with the IMU showing 40–72% accuracy, but when used in combination this pair of sensors achieved an accuracy similar to the more expensive load cell (98%. When observing dressing errors (snagging, Baxter’s sensors and the IMU data demonstrated poor sensitivity but applying machine learning methods resulted in model with high predicative accuracy and low false negative rates (≤5%. The results show that the load cell could be used independently for this application with good accuracy but a combination of the lower cost sensors could also be used without a significant loss in

31 CFR 515.321 - United States; continental United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 515.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including the Trust Territory of...

31 CFR 500.321 - United States; continental United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 500.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including U.S. trust territories...

31 CFR 535.321 - United States; continental United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 535.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof including the Trust Territory of...

CALIBRATION PROCEDURES ON OBLIQUE CAMERA SETUPS

Directory of Open Access Journals (Sweden)

G. Kemper

2016-06-01

Full Text Available Beside the creation of virtual animated 3D City models, analysis for homeland security and city planning, the accurately determination of geometric features out of oblique imagery is an important task today. Due to the huge number of single images the reduction of control points force to make use of direct referencing devices. This causes a precise camera-calibration and additional adjustment procedures. This paper aims to show the workflow of the various calibration steps and will present examples of the calibration flight with the final 3D City model. In difference to most other software, the oblique cameras are used not as co-registered sensors in relation to the nadir one, all camera images enter the AT process as single pre-oriented data. This enables a better post calibration in order to detect variations in the single camera calibration and other mechanical effects. The shown sensor (Oblique Imager is based o 5 Phase One cameras were the nadir one has 80 MPIX equipped with a 50 mm lens while the oblique ones capture images with 50 MPix using 80 mm lenses. The cameras are mounted robust inside a housing to protect this against physical and thermal deformations. The sensor head hosts also an IMU which is connected to a POS AV GNSS Receiver. The sensor is stabilized by a gyro-mount which creates floating Antenna –IMU lever arms. They had to be registered together with the Raw GNSS-IMU Data. The camera calibration procedure was performed based on a special calibration flight with 351 shoots of all 5 cameras and registered the GPS/IMU data. This specific mission was designed in two different altitudes with additional cross lines on each flying heights. The five images from each exposure positions have no overlaps but in the block there are many overlaps resulting in up to 200 measurements per points. On each photo there were in average 110 well distributed measured points which is a satisfying number for the camera calibration. In a first

A Nonlinear Dynamics-Based Estimator for Functional Electrical Stimulation: Preliminary Results From Lower-Leg Extension Experiments.

Science.gov (United States)

Allen, Marcus; Zhong, Qiang; Kirsch, Nicholas; Dani, Ashwin; Clark, William W; Sharma, Nitin

2017-12-01

Miniature inertial measurement units (IMUs) are wearable sensors that measure limb segment or joint angles during dynamic movements. However, IMUs are generally prone to drift, external magnetic interference, and measurement noise. This paper presents a new class of nonlinear state estimation technique called state-dependent coefficient (SDC) estimation to accurately predict joint angles from IMU measurements. The SDC estimation method uses limb dynamics, instead of limb kinematics, to estimate the limb state. Importantly, the nonlinear limb dynamic model is formulated into state-dependent matrices that facilitate the estimator design without performing a Jacobian linearization. The estimation method is experimentally demonstrated to predict knee joint angle measurements during functional electrical stimulation of the quadriceps muscle. The nonlinear knee musculoskeletal model was identified through a series of experiments. The SDC estimator was then compared with an extended kalman filter (EKF), which uses a Jacobian linearization and a rotation matrix method, which uses a kinematic model instead of the dynamic model. Each estimator's performance was evaluated against the true value of the joint angle, which was measured through a rotary encoder. The experimental results showed that the SDC estimator, the rotation matrix method, and EKF had root mean square errors of 2.70°, 2.86°, and 4.42°, respectively. Our preliminary experimental results show the new estimator's advantage over the EKF method but a slight advantage over the rotation matrix method. However, the information from the dynamic model allows the SDC method to use only one IMU to measure the knee angle compared with the rotation matrix method that uses two IMUs to estimate the angle.

Two calibration procedures for a gyroscope-free inertial measurement system based on a double-pendulum apparatus

Science.gov (United States)

Cappa, P.; Patanè, F.; Rossi, S.

2008-05-01

This paper presents a novel calibration algorithm to be used with a gyro-free inertial measurement unit (GF-IMU) based on the use of linear accelerometers (AC). The analytical approach can be implemented in two calibration procedures. The first procedure (P-I) is articulated in the conduction of a static trial, to compute the sensitivity and the direction of the sensing axis of each AC, followed by a dynamic trial, to determine the AC locations. By contrast, the latter procedure (P-II) consists in the calculation of the previously indicated calibration parameters by means of a dynamic trial only. The feasibility of the two calibration procedures has been investigated by testing two GF-IMUs, equipped with ten and six bi-axial linear ACs, with an ad hoc instrumented double-pendulum apparatus. P-I and P-II were compared to a calibration procedure used as a reference (P-REF), which incorporates the AC positions measured with an optoelectronic system. The experimental results we present in this paper demonstrate that (i) P-I is able to determine the calibration parameters of the AC array with a higher accuracy than P-II; (ii) consequently, the errors associated with translational (a0 - g) and rotational (\\dot{\\bm \\omega }) acceleration components for the two GF-IMUs are significantly greater using P-II than P-I and (iii) the errors in (a0 - g) and \\dot{\\bm \\omega } obtained with P-I are comparable with the ones obtainable by using P-REF. Thus, the proposed novel algorithm used in P-I, in conjunction with the double-pendulum apparatus, can be globally considered a viable tool in GF-IMU calibration.

Sensors integration for smartphone navigation: performances and future challenges

Science.gov (United States)

Aicardi, I.; Dabove, P.; Lingua, A.; Piras, M.

2014-08-01

Nowadays the modern smartphones include several sensors which are usually adopted in geomatic application, as digital camera, GNSS (Global Navigation Satellite System) receivers, inertial platform, RFID and Wi-Fi systems. In this paper the authors would like to testing the performances of internal sensors (Inertial Measurement Unit, IMU) of three modern smartphones (Samsung GalaxyS4, Samsung GalaxyS5 and iPhone4) compared to external mass-market IMU platform in order to verify their accuracy levels, in terms of positioning. Moreover, the Image Based Navigation (IBN) approach is also investigated: this approach can be very useful in hard-urban environment or for indoor positioning, as alternative to GNSS positioning. IBN allows to obtain a sub-metrical accuracy, but a special database of georeferenced images (Image DataBase, IDB) is needed, moreover it is necessary to use dedicated algorithm to resizing the images which are collected by smartphone, in order to share it with the server where is stored the IDB. Moreover, it is necessary to characterize smartphone camera lens in terms of focal length and lens distortions. The authors have developed an innovative method with respect to those available today, which has been tested in a covered area, adopting a special support where all sensors under testing have been installed. Geomatic instrument have been used to define the reference trajectory, with purpose to compare this one, with the path obtained with IBN solution. First results leads to have an horizontal and vertical accuracies better than 60 cm, respect to the reference trajectories. IBN method, sensors, test and result will be described in the paper.

Vehicle state estimation using GPS/IMU integration

NARCIS (Netherlands)

Wang, Y.; Mangnus, J.; Kostić, D.; Nijmeijer, H.; Jansen, S.T.H.

2011-01-01

New driver support systems require knowledge of the vehicle position with great accuracy and reliability. Satellite navigation (GNSS) is generally insufficiently accurate for positioning and as an alternative to using a ground station, combinations with high quality motion sensors are used in

External Aiding Methods for IMU-Based Navigation

Science.gov (United States)

2016-11-26

Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.2.1 Startup Bias...Figure Page 1 Three Distributions Implemented for Error Parameters in SAIMUN . . . . . . . . . . . . 5 2 Accelerometer Output Corrupted by Startup ...external aiding, simulate the error sources encountered in the acquisition of measurement data, emulate the navigation software, and perform a range of

Does size matter? Animal units and animal unit months

Science.gov (United States)

Lamar Smith; Joe Hicks; Scott Lusk; Mike Hemmovich; Shane Green; Sarah McCord; Mike Pellant; John Mitchell; Judith Dyess; Jim Sprinkle; Amanda Gearhart; Sherm Karl; Mike Hannemann; Ken Spaeth; Jason Karl; Matt Reeves; Dave Pyke; Jordan Spaak; Andrew Brischke; Del Despain; Matt Phillippi; Dave Weixelmann; Alan Bass; Jessie Page; Lori Metz; David Toledo; Emily Kachergis

2017-01-01

The concepts of animal units, animal unit months, and animal unit equivalents have long been used as standards for range management planning, estimating stocking rates, reporting actual use, assessing grazing fees, ranch appraisal, and other purposes. Increasing size of cattle on rangelands has led some to suggest that the definition of animal units and animal unit...

Rapanos v. United States & Carabell v. United States

Science.gov (United States)

Documents associated with guidance for implementing the definition of waters of the United States under the Clean Water Act following the Rapanos v. United States, and Carabell v. United States Supreme Court decision.

Grafting Acoustic Instruments and Signal Processing: Creative Control and Augmented Expressivity

DEFF Research Database (Denmark)

Overholt, Daniel; Freed, Adrian

In this study, work is presented on a hybrid acoustic / electric violin. The instrument has embedded processing that provides real-time simulation of acoustic body models using DSP techniques able to gradually transform a given body model into another, including extrapolations beyond the models...... acoustic violins with high fidelity. The opportunity to control a virtually malleable body while playing, i.e., a model that changes reverberant resonances in response to player input, results in interesting audio effects. Other common audio effects can also be employed and simultaneously controlled via...... the musician’s movements. For example, gestural tilting of the instrument is tracked via an embedded Inertial Measurement Unit (IMU), which can be assigned to alter parameters such as the wet/dry mix of a simple octave-doubler or other more advanced audio effect, further augmenting the expressivity...

A study on the ergonomic assessment in the workplace

Science.gov (United States)

Tee, Kian Sek; Low, Eugene; Saim, Hashim; Zakaria, Wan Nurshazwani Wan; Khialdin, Safinaz Binti Mohd; Isa, Hazlita; Awad, M. I.; Soon, Chin Fhong

2017-09-01

Ergonomics has gained attention and take into consideration by the workers in the different fields of works recently. It has given a huge impact on the workers comfort which directly affects the work efficiency and productivity. The workers have claimed to suffer from the painful postures and injuries in their workplace. Musculoskeletal disorders (MSDs) is the most common problem frequently reported by the workers. This problem occurs due to the lack of knowledge and alertness from the workers to the ergonomic in their surroundings. This paper intends to review the approaches and instruments used by the previous works of the researchers in the evaluation of the ergonomics. The two main assessment methods often used for ergonomic evaluation are Rapid Upper Limb Assessment (RULA) and Rapid Entire Body Assessment (REBA). Popular devices are Inertial Measurement Units (IMU) and Microsoft Kinect.

Localization from Visual Landmarks on a Free-Flying Robot

Science.gov (United States)

Coltin, Brian; Fusco, Jesse; Moratto, Zack; Alexandrov, Oleg; Nakamura, Robert

2016-01-01

We present the localization approach for Astrobee, a new free-flying robot designed to navigate autonomously on the International Space Station (ISS). Astrobee will accommodate a variety of payloads and enable guest scientists to run experiments in zero-g, as well as assist astronauts and ground controllers. Astrobee will replace the SPHERES robots which currently operate on the ISS, whose use of fixed ultrasonic beacons for localization limits them to work in a 2 meter cube. Astrobee localizes with monocular vision and an IMU, without any environmental modifications. Visual features detected on a pre-built map, optical flow information, and IMU readings are all integrated into an extended Kalman filter (EKF) to estimate the robot pose. We introduce several modifications to the filter to make it more robust to noise, and extensively evaluate the localization algorithm.

The study of the extreme radiation tolerance mechanisms of the bacterium Deinococcus deserti by a functional genomics approach

International Nuclear Information System (INIS)

Dulermo, R.

2009-12-01

The genome of Deinococcus deserti, a highly radiation-tolerant bacterium, was analyzed and compared to those of D. radiodurans and D. geothermalis. About 230 proteins are specifically conserved in these 3 species, including IrrE, a regulator protein essential for radio tolerance. D.deserti has several supplementary DNA repair genes, like imuY and dnaE2 (trans-lesion DNA polymerases). Moreover, D. deserti has 3 recA that code for 2 different RecA proteins (RecAC et RecAP). To study these genes, genetic tools were developed for D. deserti. Different results suggest that IrrE, required for the induction of several genes after irradiation, has peptidase activity. The 2 RecA proteins are functional for DNA repair. D. deserti is mutable by UV, which requires ImuY, DnaE2 and RecAC, but not RecAP. (author)

Interface unit

NARCIS (Netherlands)

Keyson, D.V.; Freudenthal, A.; De Hoogh, M.P.A.; Dekoven, E.A.M.

2001-01-01

The invention relates to an interface unit comprising at least a display unit for communication with a user, which is designed for being coupled with a control unit for at least one or more parameters in a living or working environment, such as the temperature setting in a house, which control unit

Robotics Laboratory to Enhance the STEM Research Experience

Science.gov (United States)

2015-04-30

Research Platforms Clearpath Robotics 2 $66,118 Open IMU system integrated with Husky SICK LMS Outdoor LIDAR Outdoor PTZ Camera NovAtel...currently focusing our attention and efforts on simultaneous localization and mapping ( SLAM ) algorithms, obstacle avoidance, and communication between

Units of measurement past, present and future international system of units

CERN Document Server

Gupta, S V

2010-01-01

It is for the first time that the subject of quantities and their respective units is dealt this much in detail a glimpse of units of measurements of base quantities of length, time, mass and volume is given for ancient India three and four dimensional systems of measurement units are critically examined establishment of the fact that only four base units are needed to describe a system of units the basics to arrive at the unit of a derived quantity are explained basic, derived and dimensionless quantities including quantity calculus are introduced life history of scientists concerned with measurements units are presented to be inspiring to working metrologists and students. The International System of Units including, Metre Convention Treaty and its various organs including International National of Weights and Measure are described. The realisation of base units is given in detail. Classes of derived units within the SI, units permitted for time to come, units outside SI but used in special fields of measur...

A Comparative Study of All-Accelerometer Strapdowns for UAV INS

National Research Council Canada - National Science Library

Cardou, Philippe; Angeles, Jorge

2005-01-01

...) for Unmanned Aerial Vehicles (UAV). Benefiting from the fabrication processes of MEMS technologies, accelerometers now offer several advantages over gyroscopes, such as low weight, compactness, high reliability and low cost, for example...

Modal estimation by FBG for flexible structures attitude control

NARCIS (Netherlands)

Jiang, Hao; Van Der Veek, B.; Dolk, V.; Kirk, D.; Gutierrez, H.

2014-01-01

This work investigates an online mode shape estimation method to estimate the time-varying modal properties and correct IMU readings in real time using distributed strain measurements of FBG sensor arrays. Compared to the notch filter approach, the proposed method removes structural vibration

Role of route previewing strategies on climbing fluency and exploratory movements

Science.gov (United States)

Cordier, Romain; Orth, Dominic; Courtine, Yoan; Croft, James L.

2017-01-01

This study examined the role of route previewing strategies on climbing fluency and on exploratory movements of the limbs, in order to understand whether previewing helps people to perceive and to realize affordances. Eight inexperienced and ten experienced climbers previewed a 10 m high route of 5b difficulty on French scale, then climbed it with a top-rope as fluently as possible. Gaze behavior was collected from an eye tracking system during the preview and allowed us to determine the number of times they scanned the route, and which of four route previewing strategies (fragmentary, ascending, zigzagging, and sequence-of-blocks) they used. Five inertial measurement units (IMU) (3D accelerometer, 3D gyroscope, 3D magnetometer) were attached to the hip, both feet, and forearms to analyze the vertical acceleration and direction of each limb and hip during the ascent. We were able to detect movement and immobility phases of each IMU using segmentation and classification processes. Depending on whether the limbs and/or hip were moving, five states of behavior were detected: immobility, postural regulation, hold exploration, hold change, and hold traction. Using cluster analysis we identified four clusters of gaze behavior during route previewing depending on route preview duration, number of scan paths, fixations duration, ascending, zigzagging, and sequence-of-blocks strategies. The number of scan paths was positively correlated with relative duration of exploration and negatively correlated with relative duration of hold changes during the ascent. Additionally, a high relative duration of sequence-of-blocks strategy and zigzagging strategy were associated with a high relative duration of immobility during the ascent. Route previewing might help to pick up functional information about reachable, graspable, and usable holds, in order to chain movements together and to find the route. In other words, route previewing might contribute to perceiving and realizing nested

Effects of hemodialysis therapy on sit-to-walk characteristics in end stage renal disease patients.

Science.gov (United States)

Soangra, Rahul; Lockhart, Thurmon E; Lach, John; Abdel-Rahman, Emaad M

2013-04-01

Patients with end stage renal diseases (ESRD) undergoing hemodialysis (HD) have high morbidity and mortality due to multiple causes; one of which is dramatically higher fall rates than the general population. In spite of the multiple efforts aiming to decrease the high mortality and improve quality of life in ESRD patients, limited success has been achieved. If adequate interventions for fall prevention are to be achieved, the functional and mobility mechanisms consistent with falls in this population must be understood. Human movements such as sit-to-walk (STW) tasks are clinically significant, and analysis of these movements provides a meaningful evaluation of postural and locomotor performance in elderly patients with functional limitations indicative of fall risks. In order to assess the effects of HD therapy on fall risks, 22 sessions of both pre- and post-HD measurements were obtained in six ESRD patients utilizing customized inertial measurement units (IMU). IMU signals were denoised using ensemble empirical mode decomposition and Savistky-Golay filtering methods to detect relevant events for identification of STW phases. The results indicated that patients were slower to get out of the chair (as measured by trunk flexion angular accelerations, time to peak trunk flexion, and overall STW completion time) following the dialysis therapy session. STW is a frequent movement in activities of daily living, and HD therapy may influence the postural and locomotor control of these movements. The analysis of STW movement may assist in not only assessing a patient's physical status, but in identifying HD-related fall risk as well. This preliminary study presents a non-invasive method of kinematic measurement for early detection of increased fall risk in ESRD patients using portable inertial sensors for out-patient monitoring. This can be helpful in understanding the pathogenesis better, and improve awareness in health care providers in targeting interventions to

Role of route previewing strategies on climbing fluency and exploratory movements.

Directory of Open Access Journals (Sweden)

Ludovic Seifert

Full Text Available This study examined the role of route previewing strategies on climbing fluency and on exploratory movements of the limbs, in order to understand whether previewing helps people to perceive and to realize affordances. Eight inexperienced and ten experienced climbers previewed a 10 m high route of 5b difficulty on French scale, then climbed it with a top-rope as fluently as possible. Gaze behavior was collected from an eye tracking system during the preview and allowed us to determine the number of times they scanned the route, and which of four route previewing strategies (fragmentary, ascending, zigzagging, and sequence-of-blocks they used. Five inertial measurement units (IMU (3D accelerometer, 3D gyroscope, 3D magnetometer were attached to the hip, both feet, and forearms to analyze the vertical acceleration and direction of each limb and hip during the ascent. We were able to detect movement and immobility phases of each IMU using segmentation and classification processes. Depending on whether the limbs and/or hip were moving, five states of behavior were detected: immobility, postural regulation, hold exploration, hold change, and hold traction. Using cluster analysis we identified four clusters of gaze behavior during route previewing depending on route preview duration, number of scan paths, fixations duration, ascending, zigzagging, and sequence-of-blocks strategies. The number of scan paths was positively correlated with relative duration of exploration and negatively correlated with relative duration of hold changes during the ascent. Additionally, a high relative duration of sequence-of-blocks strategy and zigzagging strategy were associated with a high relative duration of immobility during the ascent. Route previewing might help to pick up functional information about reachable, graspable, and usable holds, in order to chain movements together and to find the route. In other words, route previewing might contribute to perceiving and

Vision-aided inertial navigation system for robotic mobile mapping

Science.gov (United States)

Bayoud, Fadi; Skaloud, Jan

2008-04-01

A mapping system by vision-aided inertial navigation was developed for areas where GNSS signals are unreachable. In this framework, a methodology on the integration of vision and inertial sensors is presented, analysed and tested. The system employs the method of “SLAM: Simultaneous Localisation And Mapping” where the only external input available to the system at the beginning of the mapping mission is a number of features with known coordinates. SLAM is a term used in the robotics community to describe the problem of mapping the environment and at the same time using this map to determine the location of the mapping device. Differing from the robotics approach, the presented development stems from the frameworks of photogrammetry and kinematic geodesy that are merged in two filters that run in parallel: the Least-Squares Adjustment (LSA) for features coordinates determination and the Kalman filter (KF) for navigation correction. To test this approach, a mapping system-prototype comprising two CCD cameras and one Inertial Measurement Unit (IMU) is introduced. Conceptually, the outputs of the LSA photogrammetric resection are used as the external measurements for the KF that corrects the inertial navigation. The filtered position and orientation are subsequently employed in the photogrammetric intersection to map the surrounding features that are used as control points for the resection in the next epoch. We confirm empirically the dependency of navigation performance on the quality of the images and the number of tracked features, as well as on the geometry of the stereo-pair. Due to its autonomous nature, the SLAM's performance is further affected by the quality of IMU initialisation and the a-priory assumptions on error distribution. Using the example of the presented system we show that centimetre accuracy can be achieved in both navigation and mapping when the image geometry is optimal.

Simulation of motor unit recruitment and microvascular unit perfusion: spatial considerations.

Science.gov (United States)

Fuglevand, A J; Segal, S S

1997-10-01

Muscle fiber activity is the principal stimulus for increasing capillary perfusion during exercise. The control elements of perfusion, i.e., microvascular units (MVUs), supply clusters of muscle fibers, whereas the control elements of contraction, i.e., motor units, are composed of fibers widely scattered throughout muscle. The purpose of this study was to examine how the discordant spatial domains of MVUs and motor units could influence the proportion of open capillaries (designated as perfusion) throughout a muscle cross section. A computer model simulated the locations of perfused MVUs in response to the activation of up to 100 motor units in a muscle with 40,000 fibers and a cross-sectional area of 100 mm2. The simulation increased contraction intensity by progressive recruitment of motor units. For each step of motor unit recruitment, the percentage of active fibers and the number of perfused MVUs were determined for several conditions: 1) motor unit fibers widely dispersed and motor unit territories randomly located (which approximates healthy human muscle), 2) regionalized motor unit territories, 3) reversed recruitment order of motor units, 4) densely clustered motor unit fibers, and 5) increased size but decreased number of motor units. The simulations indicated that the widespread dispersion of motor unit fibers facilitates complete capillary (MVU) perfusion of muscle at low levels of activity. The efficacy by which muscle fiber activity induced perfusion was reduced 7- to 14-fold under conditions that decreased the dispersion of active fibers, increased the size of motor units, or reversed the sequence of motor unit recruitment. Such conditions are similar to those that arise in neuromuscular disorders, with aging, or during electrical stimulation of muscle, respectively.

Functional characterization of two SOS-regulated genes involved in mitomycin C resistance in Caulobacter crescentus.

Science.gov (United States)

Lopes-Kulishev, Carina O; Alves, Ingrid R; Valencia, Estela Y; Pidhirnyj, María I; Fernández-Silva, Frank S; Rodrigues, Ticiane R; Guzzo, Cristiane R; Galhardo, Rodrigo S

2015-09-01

The SOS response is a universal bacterial regulon involved in the cellular response to DNA damage and other forms of stress. In Caulobacter crescentus, previous work has identified a plethora of genes that are part of the SOS regulon, but the biological roles of several of them remain to be determined. In this study, we report that two genes, hereafter named mmcA and mmcB, are involved in the defense against DNA damage caused by mitomycin C (MMC), but not against lesions induced by other common DNA damaging agents, such as UVC light, methyl methanesulfonate (MMS) and hydrogen peroxide. mmcA is a conserved gene that encodes a member of the glyoxalases/dioxygenases protein family, and acts independently of known DNA repair pathways. On the other hand, epistasis analysis showed that mmcB acts in the same pathway as imuC (dnaE2), and is required specifically for MMC-induced mutagenesis, but not for that induced by UV light, suggesting a role for MmcB in translesion synthesis-dependent repair of MMC damage. We show that the lack of MMC-induced mutability in the mmcB strain is not caused by lack of proper SOS induction of the imuABC operon, involved in translesion synthesis (TLS) in C. crescentus. Based on this data and on structural analysis of a close homolog, we propose that MmcB is an endonuclease which creates substrates for ImuABC-mediated TLS patches. Copyright © 2015 Elsevier B.V. All rights reserved.

An innovative localisation algorithm for railway vehicles

Science.gov (United States)

Allotta, B.; D'Adamio, P.; Malvezzi, M.; Pugi, L.; Ridolfi, A.; Rindi, A.; Vettori, G.

2014-11-01

In modern railway automatic train protection and automatic train control systems, odometry is a safety relevant on-board subsystem which estimates the instantaneous speed and the travelled distance of the train; a high reliability of the odometry estimate is fundamental, since an error on the train position may lead to a potentially dangerous overestimation of the distance available for braking. To improve the odometry estimate accuracy, data fusion of different inputs coming from a redundant sensor layout may be used. The aim of this work has been developing an innovative localisation algorithm for railway vehicles able to enhance the performances, in terms of speed and position estimation accuracy, of the classical odometry algorithms, such as the Italian Sistema Controllo Marcia Treno (SCMT). The proposed strategy consists of a sensor fusion between the information coming from a tachometer and an Inertial Measurements Unit (IMU). The sensor outputs have been simulated through a 3D multibody model of a railway vehicle. The work has provided the development of a custom IMU, designed by ECM S.p.a, in order to meet their industrial and business requirements. The industrial requirements have to be compliant with the European Train Control System (ETCS) standards: the European Rail Traffic Management System (ERTMS), a project developed by the European Union to improve the interoperability among different countries, in particular as regards the train control and command systems, fixes some standard values for the odometric (ODO) performance, in terms of speed and travelled distance estimation. The reliability of the ODO estimation has to be taken into account basing on the allowed speed profiles. The results of the currently used ODO algorithms can be improved, especially in case of degraded adhesion conditions; it has been verified in the simulation environment that the results of the proposed localisation algorithm are always compliant with the ERTMS requirements

A Stationary North-Finding Scheme for an Azimuth Rotational IMU Utilizing a Linear State Equality Constraint

Directory of Open Access Journals (Sweden)

Huapeng Yu

2015-02-01

Full Text Available The Kalman filter (KF has always been used to improve north-finding performance under practical conditions. By analyzing the characteristics of the azimuth rotational inertial measurement unit (ARIMU on a stationary base, a linear state equality constraint for the conventional KF used in the fine north-finding filtering phase is derived. Then, a constrained KF using the state equality constraint is proposed and studied in depth. Estimation behaviors of the concerned navigation errors when implementing the conventional KF scheme and the constrained KF scheme during stationary north-finding are investigated analytically by the stochastic observability approach, which can provide explicit formulations of the navigation errors with influencing variables. Finally, multiple practical experimental tests at a fixed position are done on a postulate system to compare the stationary north-finding performance of the two filtering schemes. In conclusion, this study has successfully extended the utilization of the stochastic observability approach for analytic descriptions of estimation behaviors of the concerned navigation errors, and the constrained KF scheme has demonstrated its superiority over the conventional KF scheme for ARIMU stationary north-finding both theoretically and practically.

Moving State Marine SINS Initial Alignment Based on High Degree CKF

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Yong-Gang Zhang

2014-01-01

Full Text Available A new moving state marine initial alignment method of strap-down inertial navigation system (SINS is proposed based on high-degree cubature Kalman filter (CKF, which can capture higher order Taylor expansion terms of nonlinear alignment model than the existing third-degree CKF, unscented Kalman filter and central difference Kalman filter, and improve the accuracy of initial alignment under large heading misalignment angle condition. Simulation results show the efficiency and advantage of the proposed initial alignment method as compared with existing initial alignment methods for the moving state SINS initial alignment with large heading misalignment angle.

A virtual reality system for arm and hand rehabilitation

Science.gov (United States)

Luo, Zhiqiang; Lim, Chee Kian; Chen, I.-Ming; Yeo, Song Huat

2011-03-01

This paper presents a virtual reality (VR) system for upper limb rehabilitation. The system incorporates two motion track components, the Arm Suit and the Smart Glove which are composed of a range of the optical linear encoders (OLE) and the inertial measurement units (IMU), and two interactive practice applications designed for driving users to perform the required functional and non-functional motor recovery tasks. We describe the technique details about the two motion track components and the rational to design two practice applications. The experiment results show that, compared with the marker-based tracking system, the Arm Suit can accurately track the elbow and wrist positions. The repeatability of the Smart Glove on measuring the five fingers' movement can be satisfied. Given the low cost, high accuracy and easy installation, the system thus promises to be a valuable complement to conventional therapeutic programs offered in rehabilitation clinics and at home.

Aerodynamic coefficient identification package dynamic data accuracy determinations: Lessons learned

Science.gov (United States)

Heck, M. L.; Findlay, J. T.; Compton, H. R.

1983-01-01

The errors in the dynamic data output from the Aerodynamic Coefficient Identification Packages (ACIP) flown on Shuttle flights 1, 3, 4, and 5 were determined using the output from the Inertial Measurement Units (IMU). A weighted least-squares batch algorithm was empolyed. Using an averaging technique, signal detection was enhanced; this allowed improved calibration solutions. Global errors as large as 0.04 deg/sec for the ACIP gyros, 30 mg for linear accelerometers, and 0.5 deg/sec squared in the angular accelerometer channels were detected and removed with a combination is bias, scale factor, misalignment, and g-sensitive calibration constants. No attempt was made to minimize local ACIP dynamic data deviations representing sensed high-frequency vibration or instrument noise. Resulting 1sigma calibrated ACIP global accuracies were within 0.003 eg/sec, 1.0 mg, and 0.05 deg/sec squared for the gyros, linear accelerometers, and angular accelerometers, respectively.

Towards the Development of a Smart Flying Sensor: Illustration in the Field of Precision Agriculture.

Science.gov (United States)

Hernandez, Andres; Murcia, Harold; Copot, Cosmin; De Keyser, Robin

2015-07-10

Sensing is an important element to quantify productivity, product quality and to make decisions. Applications, such as mapping, surveillance, exploration and precision agriculture, require a reliable platform for remote sensing. This paper presents the first steps towards the development of a smart flying sensor based on an unmanned aerial vehicle (UAV). The concept of smart remote sensing is illustrated and its performance tested for the task of mapping the volume of grain inside a trailer during forage harvesting. Novelty lies in: (1) the development of a position-estimation method with time delay compensation based on inertial measurement unit (IMU) sensors and image processing; (2) a method to build a 3D map using information obtained from a regular camera; and (3) the design and implementation of a path-following control algorithm using model predictive control (MPC). Experimental results on a lab-scale system validate the effectiveness of the proposed methodology.

The Influence of Outdoor Shoe Sole Stiffness on the Metatarsophalangeal Joint Kinematics When Walking and Running in Different Conditions

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Paolo Mistretta

2018-02-01

Full Text Available Understanding the action of the metatarsophalangeal joint (MTP is fundamental to improving the design process of a new outdoor shoe. Coming from the stated consideration, the aim of this research is to study the influence of shoe sole stiffness and terrain slope on the MTP joint angle of subjects walking in different conditions. To pursue this intent, different data collection sessions have been carried out in-vitro and in-vivo, indoor and outdoor. Two different approaches have been used to collect gait kinematics: an IMU (Inertial Measurement Unit based system for the first campaign of tests, and a 2D video analysis for the second. Major findings showed a linear correlation between shoe sole stiffness and peak MTP joint angle during gait, as well as consistency in the value of the slope of the linear regression curves corresponding to the different conditions examined.

A High-Rate Virtual Instrument of Marine Vehicle Motions for Underwater Navigation and Ocean Remote Sensing

CERN Document Server

Gelin, Chrystel

2013-01-01

Dead-Reckoning aided with Doppler velocity measurement has been the most common method for underwater navigation for small vehicles. Unfortunately DR requires frequent position recalibrations and underwater vehicle navigation systems are limited to periodic position update when they surface. Finally standard Global Positioning System (GPS) receivers are unable to provide the rate or precision required when used on a small vessel. To overcome this, a low cost high rate motion measurement system for an Unmanned Surface Vehicle (USV) with underwater and oceanographic purposes is proposed. The proposed onboard system for the USV consists of an Inertial Measurement Unit (IMU) with accelerometers and rate gyros, a GPS receiver, a flux-gate compass, a roll and tilt sensor and an ADCP. Interfacing all the sensors proved rather challenging because of their different characteristics. The proposed data fusion technique integrates the sensors and develops an embeddable software package, using real time data fusion method...

The Author’s Guide to Writing Air Force Flight Test Center Technical Reports

Science.gov (United States)

2009-08-01

arguments about how bad is bad and how good is good; this table should apply in most cases. If you feel you have an exception to the rating table... IFR instrument flight rules --- ILS instrument landing system --- IMC instrument meteorological conditions --- IMU inertial measurement

Cloud Incubator Car: A Reliable Platform for Autonomous Driving

Directory of Open Access Journals (Sweden)

Raúl Borraz

2018-02-01

Full Text Available It appears clear that the future of road transport is going through enormous changes (intelligent transport systems, the main one being the Intelligent Vehicle (IV. Automated driving requires a huge research effort in multiple technological areas: sensing, control, and driving algorithms. We present a comprehensible and reliable platform for autonomous driving technology development as well as for testing purposes, developed in the Intelligent Vehicles Lab at the Technical University of Cartagena. We propose an open and modular architecture capable of easily integrating a wide variety of sensors and actuators which can be used for testing algorithms and control strategies. As a proof of concept, this paper presents a reliable and complete navigation application for a commercial vehicle (Renault Twizy. It comprises a complete perception system (2D LIDAR, 3D HD LIDAR, ToF cameras, Real-Time Kinematic (RTK unit, Inertial Measurement Unit (IMU, an automation of the driving elements of the vehicle (throttle, steering, brakes, and gearbox, a control system, and a decision-making system. Furthermore, two flexible and reliable algorithms are presented for carrying out global and local route planning on board autonomous vehicles.

Steam generator replacement in Bruce A Unit 1 and Unit 2

International Nuclear Information System (INIS)

Hart, R.S.

2006-01-01

The Bruce A Generating Station consists of four 900 MW class CANDU units. The reactor and Primary Heat Transport System for each Unit are housed within a reinforced concrete reactor vault. A large duct running below the reactor vaults accommodates the shared fuel handling system, and connects the four reactor vaults to the vacuum building. The reactor vaults, fuelling system duct and the vacuum building constitute the station vacuum containment system. Bruce A Unit 2 was shut down in 1995 and Bruce A Units 1, 3 and 4 were shutdown in 1997. Bruce A Units 3 and 4 were returned to service in late 2003 and are currently operating. Units 1 and 2 remain out of service. Bruce Power is currently undertaking a major rehabilitation of Bruce A Unit 1 and Units 2 that will extend the in-service life of these units by at least 25 years. Replacement of the Steam Generators (eight in each unit) is required; this work was awarded to SNC-Lavalin Nuclear (SLN). The existing steam drums (which house the steam separation and drying equipment) will be retained. Unit 2 is scheduled to be synchronized with the grid in 2009, followed by Unit 1 in 2009. Each Bruce A unit has two steam generating assemblies, one located above and to each end of the reactor. Each steam generating assembly consists of a horizontal cylindrical steam drum and four vertical Steam Generators. The vertical Steam Generators connect to individual nozzles that are located on the underside of the Steam Drum (SD). The steam drums are located in concrete shielding structures (steam drum enclosures). The lower sections of the Steam Generators penetrate the top of the reactor vaults: the containment pressure boundary is established by bellows assemblies that connect between the reactor vault roof slab and the Steam Generators. Each Steam Generators is supported from the bottom by a trapeze that is suspended from the reactor vault top structure. The Steam Generator Replacement (SGR) methodology developed by SLN for Unit 1

Case Study of Multi-Unit Risk: Multi-Unit Station Black-Out

Energy Technology Data Exchange (ETDEWEB)

Oh, Kyemin; Jang, Seung-cheol [KAERI, Daejeon (Korea, Republic of); Heo, Gyunyoung [Kyung Hee University, Yongin (Korea, Republic of)

2015-05-15

After Fukushima Daiichi Accident, importance and public concern for Multi-Unit Risk (MUR) or Probabilistic Safety Assessment (PSA) have been increased. Most of nuclear power plant sites in the world have more than two units. These sites have been facing the problems of MUR or accident such as Fukushima. In case of South Korea, there are generally more than four units on the same site and even more than ten units are also expected. In other words, sites in South Korea also have been facing same problems. Considering number of units on the same site, potential of these problems may be larger than other countries. The purpose of this paper is to perform case study based on another paper submitted in the conference. MUR is depended on various site features such as design, shared systems/structures, layout, environmental condition, and so on. Considering various dependencies, we assessed Multi-Unit Station Black-out (MSBO) accident based on Hanul Unit 3 and 4 model. In this paper, case study for multi-unit risk or PSA had been performed. Our result was incomplete to assess total multi-unit risk because of two challenging issues. First, economic impact had not been evaluated to estimate multi-unit risk. Second, large uncertainties were included in our result because of various assumptions. These issues must be resolved in the future.

Case Study of Multi-Unit Risk: Multi-Unit Station Black-Out

International Nuclear Information System (INIS)

Oh, Kyemin; Jang, Seung-cheol; Heo, Gyunyoung

2015-01-01

After Fukushima Daiichi Accident, importance and public concern for Multi-Unit Risk (MUR) or Probabilistic Safety Assessment (PSA) have been increased. Most of nuclear power plant sites in the world have more than two units. These sites have been facing the problems of MUR or accident such as Fukushima. In case of South Korea, there are generally more than four units on the same site and even more than ten units are also expected. In other words, sites in South Korea also have been facing same problems. Considering number of units on the same site, potential of these problems may be larger than other countries. The purpose of this paper is to perform case study based on another paper submitted in the conference. MUR is depended on various site features such as design, shared systems/structures, layout, environmental condition, and so on. Considering various dependencies, we assessed Multi-Unit Station Black-out (MSBO) accident based on Hanul Unit 3 and 4 model. In this paper, case study for multi-unit risk or PSA had been performed. Our result was incomplete to assess total multi-unit risk because of two challenging issues. First, economic impact had not been evaluated to estimate multi-unit risk. Second, large uncertainties were included in our result because of various assumptions. These issues must be resolved in the future

Improved Feature Matching for Mobile Devices with IMU

Directory of Open Access Journals (Sweden)

Andrea Masiero

2016-08-01

Full Text Available Thanks to the recent diffusion of low-cost high-resolution digital cameras and to the development of mostly automated procedures for image-based 3D reconstruction, the popularity of photogrammetry for environment surveys is constantly increasing in the last years. Automatic feature matching is an important step in order to successfully complete the photogrammetric 3D reconstruction: this step is the fundamental basis for the subsequent estimation of the geometry of the scene. This paper reconsiders the feature matching problem when dealing with smart mobile devices (e.g., when using the standard camera embedded in a smartphone as imaging sensor. More specifically, this paper aims at exploiting the information on camera movements provided by the inertial navigation system (INS in order to make the feature matching step more robust and, possibly, computationally more efficient. First, a revised version of the affine scale-invariant feature transform (ASIFT is considered: this version reduces the computational complexity of the original ASIFT, while still ensuring an increase of correct feature matches with respect to the SIFT. Furthermore, a new two-step procedure for the estimation of the essential matrix E (and the camera pose is proposed in order to increase its estimation robustness and computational efficiency.

1:250,000-scale Hydrologic Units of the United States

Science.gov (United States)

Steeves, Peter; Nebert, Douglas

1994-01-01

The Geographic Information Retrieval and Analysis System (GIRAS) was developed in the mid 70s to put into digital form a numberof data layers which were of interest to the USGS. One of these data layers was the Hydrologic Units. The map is based on the Hydrologic Unit Maps published by the U.S. Geological Survey Office of Water Data Coordination, together with the list descriptions and name of region, subregion, accounting units, and cataloging unit. The hydrologic units are encoded with an eight-digit number that indicates the hydrologic region (first two digits), hydrologic subregion (second two digits), accounting unit (third two digits), and cataloging unit (fourth two digits). The data produced by GIRAS was originally collected at a scale of 1:250K. Some areas, notably major cities in the west, were recompiled at a scale of 1:100K. In order to join the data together and use the data in a geographic information system (GIS) the data were processed in the ARC/INFO GUS software package. Within the GIS, the data were edgematched and the neatline boundaries between maps were removed to create a single data set for the conterminous

Multi-Unit Initiating Event Analysis for a Single-Unit Internal Events Level 1 PSA

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong San; Park, Jin Hee; Lim, Ho Gon [KAERI, Daejeon (Korea, Republic of)

2016-05-15

The Fukushima nuclear accident in 2011 highlighted the importance of considering the risks from multi-unit accidents at a site. The ASME/ANS probabilistic risk assessment (PRA) standard also includes some requirements related to multi-unit aspects, one of which (IE-B5) is as follows: 'For multi-unit sites with shared systems, DO NOT SUBSUME multi-unit initiating events if they impact mitigation capability [1].' However, the existing single-unit PSA models do not explicitly consider multi-unit initiating events and hence systems shared by multiple units (e.g., alternate AC diesel generator) are fully credited for the single unit and ignores the need for the shared systems by other units at the same site [2]. This paper describes the results of the multi-unit initiating event (IE) analysis performed as a part of the at-power internal events Level 1 probabilistic safety assessment (PSA) for an OPR1000 single unit ('reference unit'). In this study, a multi-unit initiating event analysis for a single-unit PSA was performed, and using the results, dual-unit LOOP initiating event was added to the existing PSA model for the reference unit (OPR1000 type). Event trees were developed for dual-unit LOOP and dual-unit SBO which can be transferred from dual- unit LOOP. Moreover, CCF basic events for 5 diesel generators were modelled. In case of simultaneous SBO occurrences in both units, this study compared two different assumptions on the availability of the AAC D/G. As a result, when dual-unit LOOP initiating event was added to the existing single-unit PSA model, the total CDF increased by 1∼ 2% depending on the probability that the AAC D/G is available to a specific unit in case of simultaneous SBO in both units.

Towards real-time feedback in high performance speed skating

NARCIS (Netherlands)

van der Eb, Jeroen; Zandee, Willem; van den Bogaard, Timo; Geraets, Sjoerd; Veeger, H.E.J.; Beek, Peter; Potthast, Wolfgang; Niehoff, Anja; David, Sina

2017-01-01

The aim of the current study is to evaluate several performance indicators to be used as real-time feedback in the coming experiments to enhance performance of elite speeds skaters. Six speed skaters, wearing one IMU per skate, collected data over one full training season to evaluate and pinpoint

RCS MEDDH-288 (R1), Annual Progress Report, 1 July 1972 - 30 June 1973

Science.gov (United States)

1973-07-01

consistent in size and morphology with F:imu....s •<•vyaouilensis previously reported from humans in one area in Ecuador and another in Colombia , and...of which 4~ are anthropophilic, and have been implicated in the transmission of leishmaniasis. TIhe dominant species was Lutzomyia tranidoi which I

SI units in radiology

Energy Technology Data Exchange (ETDEWEB)

Iyer, P S [Bhabha Atomic Research Centre, Bombay (India). Div. of Radiation Protection

1978-11-01

The proposal of the International Commission on Radiation Units and Measurements that the special units of radiation and radioactivity-roentgen, rad, rem and curie-be replaced by the International System (SI) of Units has been accepted by international bodies. This paper reviews the resons for introducing the new units and their features. The relation between the special units and the corresponding SI units is discussed with examples. In spite of anticipated difficulties, the commission recommends a smooth and efficient changeover to the SI units in ten years.

DAQ: Software Architecture for Data Acquisition in Sounding Rockets

Science.gov (United States)

Ahmad, Mohammad; Tran, Thanh; Nichols, Heidi; Bowles-Martinez, Jessica N.

2011-01-01

A multithreaded software application was developed by Jet Propulsion Lab (JPL) to collect a set of correlated imagery, Inertial Measurement Unit (IMU) and GPS data for a Wallops Flight Facility (WFF) sounding rocket flight. The data set will be used to advance Terrain Relative Navigation (TRN) technology algorithms being researched at JPL. This paper describes the software architecture and the tests used to meet the timing and data rate requirements for the software used to collect the dataset. Also discussed are the challenges of using commercial off the shelf (COTS) flight hardware and open source software. This includes multiple Camera Link (C-link) based cameras, a Pentium-M based computer, and Linux Fedora 11 operating system. Additionally, the paper talks about the history of the software architecture's usage in other JPL projects and its applicability for future missions, such as cubesats, UAVs, and research planes/balloons. Also talked about will be the human aspect of project especially JPL's Phaeton program and the results of the launch.

The Quadrotor Dynamic Modeling and Indoor Target Tracking Control Method

Directory of Open Access Journals (Sweden)

Dewei Zhang

2014-01-01

Full Text Available A reliable nonlinear dynamic model of the quadrotor is presented. The nonlinear dynamic model includes actuator dynamic and aerodynamic effect. Since the rotors run near a constant hovering speed, the dynamic model is simplified at hovering operating point. Based on the simplified nonlinear dynamic model, the PID controllers with feedback linearization and feedforward control are proposed using the backstepping method. These controllers are used to control both the attitude and position of the quadrotor. A fully custom quadrotor is developed to verify the correctness of the dynamic model and control algorithms. The attitude of the quadrotor is measured by inertia measurement unit (IMU. The position of the quadrotor in a GPS-denied environment, especially indoor environment, is estimated from the downward camera and ultrasonic sensor measurements. The validity and effectiveness of the proposed dynamic model and control algorithms are demonstrated by experimental results. It is shown that the vehicle achieves robust vision-based hovering and moving target tracking control.

Towards the Development of a Smart Flying Sensor: Illustration in the Field of Precision Agriculture

Directory of Open Access Journals (Sweden)

Andres Hernandez

2015-07-01

Full Text Available Sensing is an important element to quantify productivity, product quality and to make decisions. Applications, such as mapping, surveillance, exploration and precision agriculture, require a reliable platform for remote sensing. This paper presents the first steps towards the development of a smart flying sensor based on an unmanned aerial vehicle (UAV. The concept of smart remote sensing is illustrated and its performance tested for the task of mapping the volume of grain inside a trailer during forage harvesting. Novelty lies in: (1 the development of a position-estimation method with time delay compensation based on inertial measurement unit (IMU sensors and image processing; (2 a method to build a 3D map using information obtained from a regular camera; and (3 the design and implementation of a path-following control algorithm using model predictive control (MPC. Experimental results on a lab-scale system validate the effectiveness of the proposed methodology.

Attitude Determination Method by Fusing Single Antenna GPS and Low Cost MEMS Sensors Using Intelligent Kalman Filter Algorithm

Directory of Open Access Journals (Sweden)

Lei Wang

2017-01-01

Full Text Available For meeting the demands of cost and size for micronavigation system, a combined attitude determination approach with sensor fusion algorithm and intelligent Kalman filter (IKF on low cost Micro-Electro-Mechanical System (MEMS gyroscope, accelerometer, and magnetometer and single antenna Global Positioning System (GPS is proposed. The effective calibration method is performed to compensate the effect of errors in low cost MEMS Inertial Measurement Unit (IMU. The different control strategies fusing the MEMS multisensors are designed. The yaw angle fusing gyroscope, accelerometer, and magnetometer algorithm is estimated accurately under GPS failure and unavailable sideslip situations. For resolving robust control and characters of the uncertain noise statistics influence, the high gain scale of IKF is adjusted by fuzzy controller in the transition process and steady state to achieve faster convergence and accurate estimation. The experiments comparing different MEMS sensors and fusion algorithms are implemented to verify the validity of the proposed approach.

Shuttle high resolution accelerometer package experiment results - Atmospheric density measurements between 60-160 km

Science.gov (United States)

Blanchard, R. C.; Hinson, E. W.; Nicholson, J. Y.

1988-01-01

Indirect or inferred values of atmospheric density encountered by the Shuttle Orbiter during reentry have been calculated from acceleration measurements made by the High Resolution Accelerometer Package (HiRAP) and the Orbiter Inertial Measurement Unit (IMU) liner accelerometers. The atmospheric density data developed from this study represent a significant gain with respect to the body of data collected to date by various techniques in the altitude range of 60 to 160 km. The data are unique in that they cover a very wide horizontal range during each flight and provide insight into the actual density variations encountered along the reentry flight path. The data, which were collected over about 3 years, are also characterized by variations in solar activity, geomagnetic index, and local solar time. Comparison of the flight-derived densities with various atmospheric models have been made, and analyses have attempted to characterize the data and to show correlation with selected physical variables.

Variable-State-Dimension Kalman-based Filter for orientation determination using inertial and magnetic sensors.

Science.gov (United States)

Sabatini, Angelo Maria

2012-01-01

In this paper a quaternion-based Variable-State-Dimension Extended Kalman Filter (VSD-EKF) is developed for estimating the three-dimensional orientation of a rigid body using the measurements from an Inertial Measurement Unit (IMU) integrated with a triaxial magnetic sensor. Gyro bias and magnetic disturbances are modeled and compensated by including them in the filter state vector. The VSD-EKF switches between a quiescent EKF, where the magnetic disturbance is modeled as a first-order Gauss-Markov stochastic process (GM-1), and a higher-order EKF where extra state components are introduced to model the time-rate of change of the magnetic field as a GM-1 stochastic process, namely the magnetic disturbance is modeled as a second-order Gauss-Markov stochastic process (GM-2). Experimental validation tests show the effectiveness of the VSD-EKF, as compared to either the quiescent EKF or the higher-order EKF when they run separately.

Variable-State-Dimension Kalman-Based Filter for Orientation Determination Using Inertial and Magnetic Sensors

Directory of Open Access Journals (Sweden)

Angelo Maria Sabatini

2012-06-01

Full Text Available In this paper a quaternion-based Variable-State-Dimension Extended Kalman Filter (VSD-EKF is developed for estimating the three-dimensional orientation of a rigid body using the measurements from an Inertial Measurement Unit (IMU integrated with a triaxial magnetic sensor. Gyro bias and magnetic disturbances are modeled and compensated by including them in the filter state vector. The VSD-EKF switches between a quiescent EKF, where the magnetic disturbance is modeled as a first-order Gauss-Markov stochastic process (GM-1, and a higher-order EKF where extra state components are introduced to model the time-rate of change of the magnetic field as a GM-1 stochastic process, namely the magnetic disturbance is modeled as a second-order Gauss-Markov stochastic process (GM-2. Experimental validation tests show the effectiveness of the VSD-EKF, as compared to either the quiescent EKF or the higher-order EKF when they run separately.

LiDAR-based 2D Localization and Mapping System using Elliptical Distance Correction Models for UAV Wind Turbine Blade Inspection

DEFF Research Database (Denmark)

Nikolov, Ivan Adriyanov; Madsen, Claus B.

2017-01-01

for on-site outdoor localization and mapping in low feature environment using the inexpensive RPLIDAR and an 9-DOF IMU. Our algorithm geometrically simplifies the wind turbine blade 2D cross-section to an elliptical model and uses it for distance and shape correction. We show that the proposed algorithm...

Vision Aided State Estimation for Helicopter Slung Load System

DEFF Research Database (Denmark)

Bisgaard, Morten; Bendtsen, Jan Dimon; la Cour-Harbo, Anders

2007-01-01

This paper presents the design and verification of a state estimator for a helicopter based slung load system. The estimator is designed to augment the IMU driven estimator found in many helicopter UAV s and uses vision based updates only. The process model used for the estimator is a simple 4...

Discharge from an emergency department observation unit and a surgical assessment unit

DEFF Research Database (Denmark)

Schultz, Helen; Qvist, Niels; Backer Mogensen, Christian

2014-01-01

To investigate the experiences of patients with acute abdominal pain at discharge from an emergency department observation unit compared with discharge from a surgical assessment unit.......To investigate the experiences of patients with acute abdominal pain at discharge from an emergency department observation unit compared with discharge from a surgical assessment unit....

Judicial Process, Grade Eight. Resource Unit (Unit V).

Science.gov (United States)

Minnesota Univ., Minneapolis. Project Social Studies Curriculum Center.

This resource unit, developed by the University of Minnesota's Project Social Studies, introduces eighth graders to the judicial process. The unit was designed with two major purposes in mind. First, it helps pupils understand judicial decision-making, and second, it provides for the study of the rights guaranteed by the federal Constitution. Both…

Five years in the life of an inertial system operating in orbit

Science.gov (United States)

Harris, R. A.; Denhard, W. G.

1978-01-01

The paper describes the in-orbit performance of the gyroscopes and strapdown attitude reference system for the OAO-C (Copernicus) satellite, launched on Aug. 21, 1972. In order to fulfill NASA requirements, the inertial system had to: (1) operate for at least one year in orbit without failure, (2) maintain an inertial reference with an uncertainty of 50 microradians or less for at least one hour, and (3) control attitude changes with an accuracy of at least 30 parts per million. During the orbit period, the inertial system has demonstrated a capability for maintaining an inertial reference that is significantly better than these performance goals.

Steam generator replacement in Bruce A Unit 1 and Unit 2

International Nuclear Information System (INIS)

Hart, R.S.

2007-01-01

The Bruce A Generating Station consists of four 900 MW class CANDU units. The reactor and Primary Heat Transport System for each Unit are housed within a reinforced concrete reactor vault. A large duct running below the reactor vaults accommodates the shared fuel handling system, and connects the four reactor vaults to the vacuum building. The reactor vaults, fuelling system duct and the vacuum building constitute the station vacuum containment system. Bruce A Unit 2 was shut down in 1995 and Bruce A Units 1, 3 and 4 were shutdown in 1997. Bruce A Units 3 and 4 were returned to service in late 2003 and are currently operating. Units 1 and 2 remain out of service. Bruce Power is currently undertaking a major rehabilitation of Bruce A Unit 1 and Unit 2 that will extend the in-service tile of these units by at least 25 years. Replacement of the Steam Generators (eight in each unit) is required; this work was awarded to SNC-Lavalin Nuclear (SLN). The existing steam drums (which house the steam separation and drying equipment) will be retained. Unit 2 is scheduled to be synchronized with the grid in 2009, followed by Unit 1 in 2009. Each Bruce A unit has two steam generating assemblies, one located above and to each end of the reactor. Each steam generating assembly consists of a horizontal cylindrical steam drum and four vertical Steam Generators. The vertical Steam Generators connect to individual nozzles that are located on the underside of the Steam Drum (SD). The steam drums are located in concrete shielding structures (steam drum enclosures). The lower sections of the Steam Generators penetrate the top of the reactor vaults: the containment pressure boundary is established by bellows assemblies that connect between the reactor vault roof slab and the Steam Generators. Each Steam Generators is supported from he bottom by a trapeze that is suspended from the reactor vault top structure. The Steam Generator Replacement (SGR) methodology developed by SLN for Unit 1

Detector Unit

CERN Multimedia

1960-01-01

Original detector unit of the Instituut voor Kernfysisch Onderzoek (IKO) BOL project. This detector unit shows that silicon detectors for nuclear physics particle detection were already developed and in use in the 1960's in Amsterdam. Also the idea of putting 'strips' onto the silicon for high spatial resolution of a particle's impact on the detector were implemented in the BOL project which used 64 of these detector units. The IKO BOL project with its silicon particle detectors was designed, built and operated from 1965 to roughly 1977. Detector Unit of the BOL project: These detectors, notably the ‘checkerboard detector’, were developed during the years 1964-1968 in Amsterdam, The Netherlands, by the Natuurkundig Laboratorium of the N.V. Philips Gloeilampen Fabrieken. This was done in close collaboration with the Instituut voor Kernfysisch Onderzoek (IKO) where the read-out electronics for their use in the BOL Project was developed and produced.

Second unit scheduling concerns on a dual-unit nuclear project

International Nuclear Information System (INIS)

Block, H.R.; Mazzini, R.A.

1978-01-01

This paper explores the planning and scheduling problems of Unit 2 of the Susquehanna steam electric station. The causes of these problems and methods to avoid or mitigate their consequences are discussed. The Susquehanna steam electric station has two boiling water reactors rated at 1,100 MW each. Topics considered include cost factors, structures, equipment, engineering and home office, construction services, completion data phasing, work sequencing, structural dependences, and segregation. Substatial cost and schedule benefits can result if two nuclear units are designed and constructed as one integral station, and if maximum sharing of facilities and services between the units occurs. It is concluded that the cost benefits of highly integrated dual unit construction outweigh the schedule and logistical problems caused by that approach

Register of basic residential units and spatial units in the Slovak Republic

International Nuclear Information System (INIS)

Galdik, S.; Vavrinec, B.

2005-01-01

In this contribution authors deal with the register of basic residential units and spatial units in the Slovak Republic. Classification of statistical territorial units is presented. Map data and statistical data contain information about environmental impact of industrial and energetic mills

SmartUnit: Empirical Evaluations for Automated Unit Testing of Embedded Software in Industry

OpenAIRE

Zhang, Chengyu; Yan, Yichen; Zhou, Hanru; Yao, Yinbo; Wu, Ke; Su, Ting; Miao, Weikai; Pu, Geguang

2018-01-01

In this paper, we aim at the automated unit coverage-based testing for embedded software. To achieve the goal, by analyzing the industrial requirements and our previous work on automated unit testing tool CAUT, we rebuild a new tool, SmartUnit, to solve the engineering requirements that take place in our partner companies. SmartUnit is a dynamic symbolic execution implementation, which supports statement, branch, boundary value and MC/DC coverage. SmartUnit has been used to test more than one...

Dynamo: A Model Transition Framework for Dynamic Stability Control and Body Mass Manipulation

Science.gov (United States)

2011-11-01

driving at high speed, and you turn the steering wheel hard to the right and slam on the brakes, then you will end up in the oversteer regime. At the...sensors (GPS, IMU, LIDAR ) for vehicle control. Figure 17: Dynamo high-speed small UGV hardware platform We will perform experiments to measure the MTC

Aerial image geolocalization by matching its line structure with route map

Science.gov (United States)

Kunina, I. A.; Terekhin, A. P.; Khanipov, T. M.; Kuznetsova, E. G.; Nikolaev, D. P.

2017-03-01

The classic way of aerial photographs geolocation is to bind their local coordinates to a geographic coordinate system using GPS and IMU data. At the same time the possibility of geolocation in a jammed navigation field is also of interest for practical purposes. In this paper we consider one approach to visual localization relatively to a vector road map without GPS. We suggest a geolocalization algorithm which detects image line segments and looks for a geometrical transformation which provides the best mapping between the obtained segments set and line segments in the road map. We consider IMU and altimeter data still known which allows to work with orthorectified images. The problem is hence reduced to a search for a transformation which contains an arbitrary shift and bounded rotation and scaling relatively to the vector map. These parameters are estimated using RANSAC by matching straight line segments from the image to vector map segments. We also investigate how the proposed algorithm's stability is influenced by segment coordinates (two spatial and one angular).

One-unit versus two-unit cord-blood transplantation for hematologic cancers.

Science.gov (United States)

Wagner, John E; Eapen, Mary; Carter, Shelly; Wang, Yanli; Schultz, Kirk R; Wall, Donna A; Bunin, Nancy; Delaney, Colleen; Haut, Paul; Margolis, David; Peres, Edward; Verneris, Michael R; Walters, Mark; Horowitz, Mary M; Kurtzberg, Joanne

2014-10-30

Umbilical-cord blood has been used as the source of hematopoietic stem cells in an estimated 30,000 transplants. The limited number of hematopoietic cells in a single cord-blood unit prevents its use in recipients with larger body mass and results in delayed hematopoietic recovery and higher mortality. Therefore, we hypothesized that the greater numbers of hematopoietic cells in two units of cord blood would be associated with improved outcomes after transplantation. Between December 1, 2006, and February 24, 2012, a total of 224 patients 1 to 21 years of age with hematologic cancer were randomly assigned to undergo double-unit (111 patients) or single-unit (113 patients) cord-blood transplantation after a uniform myeloablative conditioning regimen and immunoprophylaxis for graft-versus-host disease (GVHD). The primary end point was 1-year overall survival. Treatment groups were matched for age, sex, self-reported race (white vs. nonwhite), performance status, degree of donor-recipient HLA matching, and disease type and status at transplantation. The 1-year overall survival rate was 65% (95% confidence interval [CI], 56 to 74) and 73% (95% CI, 63 to 80) among recipients of double and single cord-blood units, respectively (P=0.17). Similar outcomes in the two groups were also observed with respect to the rates of disease-free survival, neutrophil recovery, transplantation-related death, relapse, infections, immunologic reconstitution, and grade II-IV acute GVHD. However, improved platelet recovery and lower incidences of grade III and IV acute and extensive chronic GVHD were observed among recipients of a single cord-blood unit. We found that among children and adolescents with hematologic cancer, survival rates were similar after single-unit and double-unit cord-blood transplantation; however, a single-unit cord-blood transplant was associated with better platelet recovery and a lower risk of GVHD. (Funded by the National Heart, Lung, and Blood Institute and the

Challenges encountered by critical care unit managers in the large intensive care units.

Science.gov (United States)

Matlakala, Mokgadi C; Bezuidenhout, Martie C; Botha, Annali D H

2014-04-04

Nurses in intensive care units (ICUs) are exposed regularly to huge demands interms of fulfilling the many roles that are placed upon them. Unit managers, in particular, are responsible for the efficient management of the units and have the responsibilities of planning, organising, leading and controlling the daily activities in order to facilitate the achievement of the unit objectives. The objective of this study was to explore and present the challenges encountered by ICU managers in the management of large ICUs. A qualitative, exploratory and descriptive study was conducted at five hospital ICUs in Gauteng province, South Africa. Data were collected through individual interviews from purposively-selected critical care unit managers, then analysed using the matic coding. Five themes emerged from the data: challenges related to the layout and structure of the unit, human resources provision and staffing, provision of material resources, stressors in the unit and visitors in the ICU. Unit managers in large ICUs face multifaceted challenges which include the demand for efficient and sufficient specialised nurses; lack of or inadequate equipment that goes along with technology in ICU and supplies; and stressors in the ICU that limit the efficiency to plan, organise, lead and control the daily activities in the unit. The challenges identified call for multiple strategies to assist in the efficient management of large ICUs.

Challenges encountered by critical care unit managers in the large intensive care units

Directory of Open Access Journals (Sweden)

Mokgadi C. Matlakala

2014-04-01

Full Text Available Background: Nurses in intensive care units (ICUs are exposed regularly to huge demands interms of fulfilling the many roles that are placed upon them. Unit managers, in particular, are responsible for the efficient management of the units and have the responsibilities of planning, organising, leading and controlling the daily activities in order to facilitate the achievement of the unit objectives. Objectives: The objective of this study was to explore and present the challenges encountered by ICU managers in the management of large ICUs. Method: A qualitative, exploratory and descriptive study was conducted at five hospital ICUs in Gauteng province, South Africa. Data were collected through individual interviews from purposively-selected critical care unit managers, then analysed using the matic coding. Results: Five themes emerged from the data: challenges related to the layout and structure of the unit, human resources provision and staffing, provision of material resources, stressors in the unit and visitors in the ICU. Conclusion: Unit managers in large ICUs face multifaceted challenges which include the demand for efficient and sufficient specialised nurses; lack of or inadequate equipment that goes along with technology in ICU and supplies; and stressors in the ICU that limit the efficiency to plan, organise, lead and control the daily activities in the unit. The challenges identified call for multiple strategies to assist in the efficient management of large ICUs.

The Executive Process, Grade Eight. Resource Unit (Unit III).

Science.gov (United States)

Minnesota Univ., Minneapolis. Project Social Studies Curriculum Center.

This resource unit, developed by the University of Minnesota's Project Social Studies, introduces eighth graders to the executive process. The unit uses case studies of presidential decision making such as the decision to drop the atomic bomb on Hiroshima, the Cuba Bay of Pigs and quarantine decisions, and the Little Rock decision. A case study of…

United Cerebral Palsy

Science.gov (United States)

... your local affiliate Find your local affiliate United Cerebral Palsy United Cerebral Palsy (UCP) is a trusted resource for individuals with Cerebral Palsy and other disabilities and their networks. Individuals with ...

Rapid Annealing of Iron Implanted Hg(1-x)Cd(x)Te

Science.gov (United States)

1990-03-01

Alnrroveii rFoi’ PubikI Release; distributin tilIntl ted DTICELECTEJUN 12 IMU’ BEest Available Cop, D i ..:6 (J,•, 4iL& , AD Rapid Annealing of Ion...Recently, we have received from Or.J. Dinan of the Night Vision and Electro-optic Army Labs at Fort Belvoir a few electrically uncharacterized Hg

GOES-R active vibration damping controller design, implementation, and on-orbit performance

Science.gov (United States)

Clapp, Brian R.; Weigl, Harald J.; Goodzeit, Neil E.; Carter, Delano R.; Rood, Timothy J.

2018-01-01

GOES-R series spacecraft feature a number of flexible appendages with modal frequencies below 3.0 Hz which, if excited by spacecraft disturbances, can be sources of undesirable jitter perturbing spacecraft pointing. To meet GOES-R pointing stability requirements, the spacecraft flight software implements an Active Vibration Damping (AVD) rate control law which acts in parallel with the nadir point attitude control law. The AVD controller commands spacecraft reaction wheel actuators based upon Inertial Measurement Unit (IMU) inputs to provide additional damping for spacecraft structural modes below 3.0 Hz which vary with solar wing angle. A GOES-R spacecraft dynamics and attitude control system identified model is constructed from pseudo-random reaction wheel torque commands and IMU angular rate response measurements occurring over a single orbit during spacecraft post-deployment activities. The identified Fourier model is computed on the ground, uplinked to the spacecraft flight computer, and the AVD controller filter coefficients are periodically computed on-board from the Fourier model. Consequently, the AVD controller formulation is based not upon pre-launch simulation model estimates but upon on-orbit nadir point attitude control and time-varying spacecraft dynamics. GOES-R high-fidelity time domain simulation results herein demonstrate the accuracy of the AVD identified Fourier model relative to the pre-launch spacecraft dynamics and control truth model. The AVD controller on-board the GOES-16 spacecraft achieves more than a ten-fold increase in structural mode damping for the fundamental solar wing mode while maintaining controller stability margins and ensuring that the nadir point attitude control bandwidth does not fall below 0.02 Hz. On-orbit GOES-16 spacecraft appendage modal frequencies and damping ratios are quantified based upon the AVD system identification, and the increase in modal damping provided by the AVD controller for each structural mode is

THE PERFORMANCE OF A TIGHT INS/GNSS/PHOTOGRAMMETRIC INTEGRATION SCHEME FOR LAND BASED MMS APPLICATIONS IN GNSS DENIED ENVIRONMENTS

Directory of Open Access Journals (Sweden)

C.-H. Chu

2016-06-01

Full Text Available The early development of mobile mapping system (MMS was restricted to applications that permitted the determination of the elements of exterior orientation from existing ground control. Mobile mapping refers to a means of collecting geospatial data using mapping sensors that are mounted on a mobile platform. Research works concerning mobile mapping dates back to the late 1980s. This process is mainly driven by the need for highway infrastructure mapping and transportation corridor inventories. In the early nineties, advances in satellite and inertial technology made it possible to think about mobile mapping in a different way. Instead of using ground control points as references for orienting the images in space, the trajectory and attitude of the imager platform could now be determined directly. Cameras, along with navigation and positioning sensors are integrated and mounted on a land vehicle for mapping purposes. Objects of interest can be directly measured and mapped from images that have been georeferenced using navigation and positioning sensors. Direct georeferencing (DG is the determination of time-variable position and orientation parameters for a mobile digital imager. The most common technologies used for this purpose today are satellite positioning using the Global Navigation Satellite System (GNSS and inertial navigation using an Inertial Measuring Unit (IMU. Although either technology used along could in principle determine both position and orientation, they are usually integrated in such a way that the IMU is the main orientation sensor, while the GNSS receiver is the main position sensor. However, GNSS signals are obstructed due to limited number of visible satellites in GNSS denied environments such as urban canyon, foliage, tunnel and indoor that cause the GNSS gap or interfered by reflected signals that cause abnormal measurement residuals thus deteriorates the positioning accuracy in GNSS denied environments. This study aims

Functional Data Analysis of Spaceflight-Induced Changes in Coordination and Phase in Head Pitch Acceleration During Treadmill Walking

Science.gov (United States)

Miller, Christopher; Peters, Brian; Feiveson, Alan; Bloomberg, Jacob

2011-01-01

Astronauts returning from spaceflight experience neurovestibular disturbances during head movements and attempt to mitigate them by limiting head motion. Analyses to date of the head movements made during walking have concentrated on amplitude and variability measures extracted from ensemble averages of individual gait cycles. Phase shifts within each gait cycle can be determined by functional data analysis through the computation of time-warping functions. Large, localized variations in the timing of peaks in head kinematics may indicate changes in coordination. The purpose of this study was to determine timing changes in head pitch acceleration of astronauts during treadmill walking before and after flight. Six astronauts (5M/1F; age = 43.5+/-6.4yr) participated in the study. Subjects walked at 1.8 m/sec (4 mph) on a motorized treadmill while reading optotypes displayed on a computer screen 4 m in front of their eyes. Three-dimensional motion of the subject s head was recorded with an Inertial Measurement Unit (IMU) device. Data were recorded twice before flight and four times after landing. The head pitch acceleration was calculated by taking the time derivative of the pitch velocity data from the IMU. Data for each session with each subject were time-normalized into gait cycles, then registered to align significant features and create a mean curve. The mean curves of each postflight session for each subject were re-registered based on their preflight mean curve to create time-warping functions. The root mean squares (RMS) of these warping functions were calculated to assess the deviation of head pitch acceleration mean curves in each postflight session from the preflight mean curve. After landing, most crewmembers exhibited localized shifts within their head pitch acceleration regimes, with the greatest deviations in RMS occurring on landing day or 1 day after landing. These results show that the alteration of head pitch coordination due to spaceflight may be

Predictive Sea State Estimation for Automated Ride Control and Handling - PSSEARCH

Science.gov (United States)

Huntsberger, Terrance L.; Howard, Andrew B.; Aghazarian, Hrand; Rankin, Arturo L.

2012-01-01

PSSEARCH provides predictive sea state estimation, coupled with closed-loop feedback control for automated ride control. It enables a manned or unmanned watercraft to determine the 3D map and sea state conditions in its vicinity in real time. Adaptive path-planning/ replanning software and a control surface management system will then use this information to choose the best settings and heading relative to the seas for the watercraft. PSSEARCH looks ahead and anticipates potential impact of waves on the boat and is used in a tight control loop to adjust trim tabs, course, and throttle settings. The software uses sensory inputs including IMU (Inertial Measurement Unit), stereo, radar, etc. to determine the sea state and wave conditions (wave height, frequency, wave direction) in the vicinity of a rapidly moving boat. This information can then be used to plot a safe path through the oncoming waves. The main issues in determining a safe path for sea surface navigation are: (1) deriving a 3D map of the surrounding environment, (2) extracting hazards and sea state surface state from the imaging sensors/map, and (3) planning a path and control surface settings that avoid the hazards, accomplish the mission navigation goals, and mitigate crew injuries from excessive heave, pitch, and roll accelerations while taking into account the dynamics of the sea surface state. The first part is solved using a wide baseline stereo system, where 3D structure is determined from two calibrated pairs of visual imagers. Once the 3D map is derived, anything above the sea surface is classified as a potential hazard and a surface analysis gives a static snapshot of the waves. Dynamics of the wave features are obtained from a frequency analysis of motion vectors derived from the orientation of the waves during a sequence of inputs. Fusion of the dynamic wave patterns with the 3D maps and the IMU outputs is used for efficient safe path planning.

Hanford Site Waste management units report

International Nuclear Information System (INIS)

1992-01-01

This report summarizes the operable units in several areas of the Hanford Site Waste Facility. Each operable unit has several waste units (crib, ditch, pond, etc.). The operable units are summarized by describing each was unit. Some of the descriptions are unit name, unit type, waste category start data, site description, etc. The descriptions will vary for each waste unit in each operable unit and area of the Hanford Site

Allocating multiple units

DEFF Research Database (Denmark)

Tranæs, Torben; Krishna, Kala

2002-01-01

This paper studies the allocation and rent distribution in multi-unit, combinatorial-bid auctions under complete information. We focus on the natural multi-unit analogue of the first-price auction, where buyers bid total payments, pay their bids, and where the seller allocates goods to maximize his...... auction, which is the multi unit analogue of a second-price auction. Furthermore, we characterize these equilibria when valuations take a number of different forms: diminishing marginal valuations, increasing average valuations, and marginal valuations with single turning points...

Adaptive Kalman Filter of Transfer Alignment with Un-modeled Wing Flexure of Aircraft

Institute of Scientific and Technical Information of China (English)

无

2008-01-01

The alignment accuracy of the strap-down inertial navigation system (SINS) of airborne weapon is greatly degraded by the dynamic wing flexure of the aircraft. An adaptive Kalman filter uses innovation sequences based on the maximum likelihood estimated criterion to adapt the system noise covariance matrix and the measurement noise covariance matrix on line, which is used to estimate the misalignment if the model of wing flexure of the aircraft is unknown. From a number of simulations, it is shown that the accuracy of the adaptive Kalman filter is better than the conventional Kalman filter, and the erroneous misalignment models of the wing flexure of aircraft will cause bad estimation results of Kalman filter using attitude match method.

Vision-IMU based collaborative control of a blind UAV

NARCIS (Netherlands)

Hoogervorst, R.; Stramigioli, Stefano; Wopereis, Han Willem; Fumagalli, Matteo

2015-01-01

Position estimation of UAVs is usually done using onboard sensors such as GPS and camera. However, in certain practical situations, the measurements of both the GPS and the onboard camera of the UAV might not always be available or reliable. This paper investigates the possibility to overcome

SI units in engineering and technology

CERN Document Server

Qasim, S H

2016-01-01

SI Units in Engineering and Technology focuses on the use of the International System of Units-Systeme International d'Unités (SI). The publication first elaborates on the SI, derivation of important engineering units, and derived SI units in science and engineering. Discussions focus on applied mechanics in mechanical engineering, electrical and magnetic units, stress and pressure, work and energy, power and force, and magnitude of SI units. The text then examines SI units conversion tables and engineering data in SI units. Tables include details on the sectional properties of metals in SI units, physical properties of important molded plastics, important physical constants expressed in SI units, and temperature, area, volume, and mass conversion. Tables that show the mathematical constants, standard values expressed in SI units, and Tex count conversion are also presented. The publication is a dependable source of data for researchers interested in the use of the International System of Units-Systeme Inter...

Decision unit program

International Nuclear Information System (INIS)

Madjar, N.; Pastor, C.; Chambon, B.; Drain, D.; Giorni, A.; Dauchy, A.

1981-01-01

A decision unit has been built to simplify the electronic logic set-up in multi-detectors experiments. This unit, designed with fast memories used as decision making tables, replaces conventional logic modules. Nine inputs are provided for receiving the fast detector signals (charged particles, gammas, neutrons, ...). Fifteen independent outputs allow the identification of the choosen events among the 2 9 possible events. A CAMAC interface between the unit and the computer, or a manual control auxiliary module, is used to load, in the memory, the pattern of the choosen events [fr

A multiplicity logic unit

International Nuclear Information System (INIS)

Bialkowski, J.; Moszynski, M.; Zagorski, A.

1981-01-01

The logic diagram principle of operation and some details of the design of the multiplicity logic unit are presented. This unit was specially designed to fulfil the requirements of a multidetector arrangement for gamma-ray multiplicity measurements. The unit is equipped with 16 inputs controlled by a common coincidence gate. It delivers a linear output pulse with the height proportional to the multiplicity of coincidences and logic pulses corresponding to 0, 1, ... up to >= 5-fold coincidences. These last outputs are used to steer the routing unit working with the multichannel analyser. (orig.)

UniTed

OpenAIRE

Harma, Eero

2010-01-01

UniTed on Teddy boy- tyylistä inspiroitunut kevät/kesä mallisto naisille.Mallistossa yhdistyy perinteinen teddy boy- vaatetus ja klassinen feminiinisyys, sekä menneisyys ja nykyisyys. Suunnittelun lähtökohtia olivat naisellisuus, tyylikkyys ja pyrkimys luoda nykyaikaista suunnittelua menneisyydestä lainaillen. United is a teddy boy- style inspired spring/summer collection for women. The collection combines traditional Teddy boy style with classical feminity and past with the present. The b...

Hanford Site waste management units report

International Nuclear Information System (INIS)

1993-04-01

The Hanford Site Waste Management Units Report was originated to provide information responsive to Section 3004(u) of the Hazardous and Solid Waste Amendments of the 1984. This report provides a comprehensive inventory of all types of waste management units at the Hanford Site, including a description of the units and the waste they contain. Waste management units in the report include: (1) Resource Conservation and Recovery Act of 1976 (RCRA) disposal units, (2) Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) disposal units, (3) unplanned releases, (4) inactive contaminated structures, (5) RCRA treatment, storage, and disposal (TSD) units, and (6) other storage areas. Because of the comprehensive nature of the units report, the list of units is more extensive than required by Section 3004(u) of Hazardous and Solid Waste Amendments of the 1984. In Sections 3.0 through 6.0 of this report, the four aggregate areas are subdivided into their operable units. The operable units are further divided into two parts: (1) those waste management units assigned to the operable unit that will be remediated as part of the Environmental Restoration Remedial Actions (ERRA) Program, and (2) those waste management units located within the operable unit boundaries but not assigned to the ERRA program. Only some operable unit sections contain the second part.Volume two contains Sections 4.0 through 6.0 and the following appendices: Appendix A -- acronyms and definition of terms; Appendix B -- unplanned releases that are not considered to be units; and Appendix C -- operable unit maps

Hanford Site waste management units report

International Nuclear Information System (INIS)

1993-04-01

The Hanford Site Waste Management Units Report was originated to provide information responsive to Section 3004(u) of the Hazardous and Solid Waste Amendments of the 1984. This report provides a comprehensive inventory of all types of waste management units at the Hanford Site, including a description of the units and the waste they contain. Waste management units in the report include: (1) Resource Conservation and Recovery Act of 1976 (RCRA) disposal units, (2) Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) disposal units, (3) unplanned releases, (4) inactive contaminated structures, (5) RCRA treatment, storage, and disposal (TSD) units, and (6) other storage areas. Because of the comprehensive nature of the units report, the list of units is more extensive than required by Section 3004(u) of Hazardous and Solid Waste Amendments of the 1984. In Sections 3.0 through 6.0 of this report, the four aggregate areas are subdivided into their operable units. The operable units are further divided into two parts: (1) those waste management units assigned to the operable unit that will be remediated as part of the Environmental Restoration Remedial Actions (ERRA) Program, and (2) those waste management units located within the operable unit boundaries but not assigned to the ERRA program. Only some operable unit sections contain the second part

SI units in radiation protection

International Nuclear Information System (INIS)

Jain, V.K.; Soman, S.D.

1978-01-01

International System of Units abbreviated as SI units has been adopted by most of the countries of the world. Following this development, the implementation of SI units has become mandatory with a transition period of about ten years. Some of the journals have already adopted the SI units and any material sent for publication to them must use only these. International Commission on Radiation Units and Measurement (ICRU) published letters in several journals including Physics in Medicine and Biology, Health Physics, British Journal of Radiology, etc. outlining the latest recommendations on SI units to elicit the reactions of scientists in the general field of radiological sciences. Reactions to the letters were numerous as can be seen in the correspondence columns of these journals for the last few years and ranged from great misgivings and apprehension to support and appreciation. SI units have also been the subject of editorial comments in several journals. On the basis of a survey of this literature, it may be said that there was general agreement on the long term advantage of SI units inspite of some practical difficulties in their use particularly in the initial stages. This report presents a review of SI units in radiological sciences with a view to familiarize the users with the new units in terms of the old. A time table for the gradual changeover to the SI units is also outlined. (auth.)

SI units in biomedical dosimetry

International Nuclear Information System (INIS)

Liden, K.

1975-01-01

The International commission on radiation units and measurements (ICRU), during the period from 1953 to 1962 presented its definitions of the quantities absorbed dose, exposure, activity, and dose equivalent and the corresponding special units the rad, the roentgen, the curie, and the rem. At the same time an international practical system of units was developed, Le Systeme International d'Unites (SI). It was adopted by the 11th Conference Generale des Poids et Mesures (CGPM) in 1960 and is now officially introduced in almost all countries. The general implementation of the SI means difficulties for the future use of the special radiation units, because the numerical factors involved prevent their adoption as SI units. In view of this, and after having sampled the opinion in the radiological field, the ICRU prepared a Statement on Units in July, 1974 which was forwarded to the Comite International des Poids et Mesures (CIPM) and its Comite Consultatif des Unites (CCU) for consideration. As a result of this statement the CIPM has now proposed, that the 15rh CGPM adopt special names for two SI units, namely the becquerel, symbol Bq, for the unit of activity of radionuclides equal to the reciprocal second, s 1- , and the gray, symbol Gy, for the unit of absorbed dose equal to the joule per kilogram, J/kg. The 15th CGPM will consider this matter in May, 1975. (author)

Cross Selling Implementation From Outpatient Unit to Radiology Unit in Semen Gresik Hospital

OpenAIRE

Rochmah, Thinni Nurul; Faradisa, Mutiara Ayu

2013-01-01

Thelow visitingnumberinhospital€™sunitarecloselyrelatedtomarketingactivities,includinginternal marketing which consistsof cross sellingfromother units.Thisstudy aims toanalyze crossselling implementation from Outpatient Unit to Radiology Unit in Semen Gresik Hospital. This study was a cross sectional analytic design. Samplewastakenbysimple random samplingwithsamplesize25respondents.Independentvariableswere marketing policy,employee commitment,perception, motivation,andreadiness ofcross sellin...

Drilling unit

Energy Technology Data Exchange (ETDEWEB)

Umanchik, N P; Demin, A V; Khrustalev, N N; Linnik, G N; Lovchev, S V; Rozin, M M; Sidorov, R V; Sokolov, S I; Tsaregradskiy, Yu P

1981-01-01

A drilling unit is proposed which includes a hydraulic lifter, hydraulic multiple-cylinder pump with valve distribution and sectional drilling pump with separators of the working and flushing fluid. In order to reduce metal consumption and the overall dimensions of the drilling unit, the working cavity of each cylinder of the hydraulic multiple-cylinder pump is equipped with suction and injection valves and is hydraulically connected to the working cavity by one of the sections of the drilling pump.

7 CFR 1160.104 - United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true United States. 1160.104 Section 1160.104 Agriculture... Definitions § 1160.104 United States. United States means the 48 contiguous states in the continental United States and the District of Columbia, except that United States means the 50 states of the United States...

Multiple Time Series Node Synchronization Utilizing Ambient Reference

Science.gov (United States)

2014-12-31

4) Integration with other developing environments (C, C++, Matlab, Java ); 5) Quality, compactness, maturity; 6) Cost. During the duration...Flexibility of parameters; 3) Number and type of supported sensors; 4) Integration with other developing environments (C, C++, Matlab, Java ); 5) Quality...and 9 Hz for the HR-monitor. The IMU collected acceleration at two different scales, 16 and 6 , angular velocity ( / ), magnetometer ( ) and

Protective mechanical ventilation in United Kingdom critical care units: A multicentre audit.

Science.gov (United States)

Newell, Christopher P; Martin, Matthew J; Richardson, Neil; Bourdeaux, Christopher P

2017-05-01

Lung protective ventilation is becoming increasingly used for all critically ill patients being mechanically ventilated on a mandatory ventilator mode. Compliance with the universal application of this ventilation strategy in intensive care units in the United Kingdom is unknown. This 24-h audit of ventilation practice took place in 16 intensive care units in two regions of the United Kingdom. The mean tidal volume for all patients being ventilated on a mandatory ventilator mode was 7.2(±1.4) ml kg -1 predicted body weight and overall compliance with low tidal volume ventilation (≤6.5 ml kg -1 predicted body weight) was 34%. The mean tidal volume for patients ventilated with volume-controlled ventilation was 7.0(±1.2) ml kg -1 predicted body weight and 7.9(±1.8) ml kg -1 predicted body weight for pressure-controlled ventilation ( P  < 0.0001). Overall compliance with recommended levels of positive end-expiratory pressure was 72%. Significant variation in practice existed both at a regional and individual unit level.

Analysis of Serbian Military Riverine Units Capability for Participation in the United Nations Peacekeeping Operations

Directory of Open Access Journals (Sweden)

Slobodan Radojevic

2017-06-01

Full Text Available This paper analyses required personnel, training capacities and equipment for participation in the United Nations peacekeeping operations with the riverine elements. In order to meet necessary capabilities for engagement in United Nations peacekeeping operations, Serbian military riverine units have to be compatible with the issued UN requirements. Serbian Armed Forces have the potential to reach such requirements with the River Flotilla as a pivot for the participation in UN missions. Serbian Military Academy adopted and developed educational and training program in accordance with the provisions and recommendations of the IMO conventions and IMO model courses. Serbian Military Academy has opportunities for education and training military riverine units for participation in the United Nations peacekeeping operations. Moreover, Serbia has Multinational Operations Training Center and Peacekeeping Operations Center certified to provide selection, training, equipping and preparations of individuals and units to the United Nations multinational operations.

Patient stress in intensive care: comparison between a coronary care unit and a general postoperative unit

Science.gov (United States)

Dias, Douglas de Sá; Resende, Mariane Vanessa; Diniz, Gisele do Carmo Leite Machado

2015-01-01

Objective To evaluate and compare stressors identified by patients of a coronary intensive care unit with those perceived by patients of a general postoperative intensive care unit. Methods This cross-sectional and descriptive study was conducted in the coronary intensive care and general postoperative intensive care units of a private hospital. In total, 60 patients participated in the study, 30 in each intensive care unit. The stressor scale was used in the intensive care units to identify the stressors. The mean score of each item of the scale was calculated followed by the total stress score. The differences between groups were considered significant when p < 0.05. Results The mean ages of patients were 55.63 ± 13.58 years in the coronary intensive care unit and 53.60 ± 17.47 years in the general postoperative intensive care unit. For patients in the coronary intensive care unit, the main stressors were “being in pain”, “being unable to fulfill family roles” and “being bored”. For patients in the general postoperative intensive care unit, the main stressors were “being in pain”, “being unable to fulfill family roles” and “not being able to communicate”. The mean total stress scores were 104.20 ± 30.95 in the coronary intensive care unit and 116.66 ± 23.72 (p = 0.085) in the general postoperative intensive care unit. When each stressor was compared separately, significant differences were noted only between three items. “Having nurses constantly doing things around your bed” was more stressful to the patients in the general postoperative intensive care unit than to those in the coronary intensive care unit (p = 0.013). Conversely, “hearing unfamiliar sounds and noises” and “hearing people talk about you” were the most stressful items for the patients in the coronary intensive care unit (p = 0.046 and 0.005, respectively). Conclusion The perception of major stressors and the total stress score were similar between patients

METRIC context unit architecture

Energy Technology Data Exchange (ETDEWEB)

Simpson, R.O.

1988-01-01

METRIC is an architecture for a simple but powerful Reduced Instruction Set Computer (RISC). Its speed comes from the simultaneous processing of several instruction streams, with instructions from the various streams being dispatched into METRIC's execution pipeline as they become available for execution. The pipeline is thus kept full, with a mix of instructions for several contexts in execution at the same time. True parallel programming is supported within a single execution unit, the METRIC Context Unit. METRIC's architecture provides for expansion through the addition of multiple Context Units and of specialized Functional Units. The architecture thus spans a range of size and performance from a single-chip microcomputer up through large and powerful multiprocessors. This research concentrates on the specification of the METRIC Context Unit at the architectural level. Performance tradeoffs made during METRIC's design are discussed, and projections of METRIC's performance are made based on simulation studies.

LIDAR AND INS FUSION IN PERIODS OF GPS OUTAGES FOR MOBILE LASER SCANNING MAPPING SYSTEMS

Directory of Open Access Journals (Sweden)

I. Klein

2012-09-01

Full Text Available Mobile laser scanning systems are becoming an increasingly popular means to obtain 3D coverage on a large scale. To perform the mapping, the exact position of the vehicle must be known throughout the trajectory. Exact position is achieved via integration of Global Positioning Systems (GPS and Inertial Navigation Systems (INS. Yet, in urban environments, cases of complete or even partial GPS outages may occur leaving the navigation solution to rely only on the INS. The INS navigation solution degrades with time as the Inertial Measurement Unit (IMU measurements contains noise, which permeates into the navigation equations. Degradation of the position determination leads to loss of data in such segments. To circumvent such drift and its effects, we propose fusing INS with lidar data by using building edges. This detection of edges is then translated into position data, which is used as an aiding to the INS. It thereby enables the determination of the vehicle position with a satisfactory level accuracy, sufficient to perform the laser-scanning based mapping in those outage periods.

Trajectory Reconstruction and Uncertainty Analysis Using Mars Science Laboratory Pre-Flight Scale Model Aeroballistic Testing

Science.gov (United States)

Lugo, Rafael A.; Tolson, Robert H.; Schoenenberger, Mark

2013-01-01

As part of the Mars Science Laboratory (MSL) trajectory reconstruction effort at NASA Langley Research Center, free-flight aeroballistic experiments of instrumented MSL scale models was conducted at Aberdeen Proving Ground in Maryland. The models carried an inertial measurement unit (IMU) and a flush air data system (FADS) similar to the MSL Entry Atmospheric Data System (MEADS) that provided data types similar to those from the MSL entry. Multiple sources of redundant data were available, including tracking radar and on-board magnetometers. These experimental data enabled the testing and validation of the various tools and methodologies that will be used for MSL trajectory reconstruction. The aerodynamic parameters Mach number, angle of attack, and sideslip angle were estimated using minimum variance with a priori to combine the pressure data and pre-flight computational fluid dynamics (CFD) data. Both linear and non-linear pressure model terms were also estimated for each pressure transducer as a measure of the errors introduced by CFD and transducer calibration. Parameter uncertainties were estimated using a "consider parameters" approach.

Modeling and Calculation of Dent Based on Pipeline Bending Strain

Directory of Open Access Journals (Sweden)

Qingshan Feng

2016-01-01

Full Text Available The bending strain of long-distance oil and gas pipelines can be calculated by the in-line inspection tool which used inertial measurement unit (IMU. The bending strain is used to evaluate the strain and displacement of the pipeline. During the bending strain inspection, the dent existing in the pipeline can affect the bending strain data as well. This paper presents a novel method to model and calculate the pipeline dent based on the bending strain. The technique takes inertial mapping data from in-line inspection and calculates depth of dent in the pipeline using Bayesian statistical theory and neural network. To verify accuracy of the proposed method, an in-line inspection tool is used to inspect pipeline to gather data. The calculation of dent shows the method is accurate for the dent, and the mean relative error is 2.44%. The new method provides not only strain of the pipeline dent but also the depth of dent. It is more benefit for integrity management of pipeline for the safety of the pipeline.

Hanford Site Waste Managements Units reports

International Nuclear Information System (INIS)

1992-01-01

The Hanford Site Waste Management Units Report (HSWMUR) was originated to provide information responsive to Section 3004(u) of the Hazardous and Solid Waste Amendments (HSWA) of the 1984 United States Code (USC 1984). This report provides a comprehensive inventory of all types of waste management units at the Hanford Site, including a description of the units and the waste they contain. Waste management units in this report include: (1) Resource Conservation and Recovery Act of 1976 (RCRA) disposal units, (2) Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) disposal units, (3) unplanned releases, (4) inactive contaminated structures, (5) RCRA treatment, storage, and disposal (TSD) units, and (6) other storage areas. Because of the comprehensive nature of this report, the listing of sites is more extensive than required by Section 3004(u) of HSWA. The information in this report is extracted from the Waste Information Data System (WIDS). The WIDS provides additional information concerning the waste management units contained in this report and is maintained current with changes to these units. This report is updated annually if determined necessary per the Hanford Federal Facility Agreement and Consent Order Order (commonly referred to as the Tri-Party Agreement, Ecology et al. 1990). This report identifies 1,414 waste management units. Of these, 1,015 units are identified as solid waste management units (SWMU), and 342 are RCRA treatment, storage, and disposal units. The remaining 399 are comprised mainly of one-time spills to the environment, sanitary waste disposal facilities (i.e., septic tanks), and surplus facilities awaiting decontamination and decommissioning

3 CFR - Waiver of Reimbursement Under the United Nations Participation Act to Support the United Nations...

Science.gov (United States)

2010-01-01

... Participation Act to Support the United Nations/African Union Mission in Darfur Presidential Documents Other... the United Nations Participation Act to Support the United Nations/African Union Mission in Darfur... the United Nations/African Union Mission in Darfur to support the airlift of equipment for...

Gas-centrifuge unit

International Nuclear Information System (INIS)

Stark, T.M.

1977-01-01

An isotope-enrichment unit is described for separating a gaseous mixture feedstock including a compound of a light nuclear isotope at a predetermined concentration and a compound of a heavy nuclear isotope at a predetermined concentration into at least two unit-output fractions including a waste fraction depleted in the light isotope to a predetermined concentration and a product fraction enriched in the light isotope to a predetermined concentration. The unit comprises a first group of cascades of gas centrifuges, each cascade having an enriching stage, a stripping stage, an input, a light-fraction output, and a heavy-fraction output for separating the gaseous-mixture feed stock into light and heavy gaseous-mixture fractions; and an auxillary cascade

31 CFR 800.225 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 800.225 Section 800... TAKEOVERS BY FOREIGN PERSONS Definitions § 800.225 United States. The term United States or U.S. means the United States of America, the States of the United States, the District of Columbia, and any commonwealth...

Pricise Target Geolocation and Tracking Based on Uav Video Imagery

Science.gov (United States)

Hosseinpoor, H. R.; Samadzadegan, F.; Dadrasjavan, F.

2016-06-01

There is an increasingly large number of applications for Unmanned Aerial Vehicles (UAVs) from monitoring, mapping and target geolocation. However, most of commercial UAVs are equipped with low-cost navigation sensors such as C/A code GPS and a low-cost IMU on board, allowing a positioning accuracy of 5 to 10 meters. This low accuracy cannot be used in applications that require high precision data on cm-level. This paper presents a precise process for geolocation of ground targets based on thermal video imagery acquired by small UAV equipped with RTK GPS. The geolocation data is filtered using an extended Kalman filter, which provides a smoothed estimate of target location and target velocity. The accurate geo-locating of targets during image acquisition is conducted via traditional photogrammetric bundle adjustment equations using accurate exterior parameters achieved by on board IMU and RTK GPS sensors, Kalman filtering and interior orientation parameters of thermal camera from pre-flight laboratory calibration process. The results of this study compared with code-based ordinary GPS, indicate that RTK observation with proposed method shows more than 10 times improvement of accuracy in target geolocation.

Wprowadzenie do teorii kapitalizmu kognitywnego: kapitalizm kognitywny jako reżim akumulacji

Directory of Open Access Journals (Sweden)

Mikołaj Ratajczak

2015-12-01

Full Text Available Artykuł stanowi zarazem historyczne, jak i systematyczne oraz problemowe wprowadzenie do teorii kapitalizmu kognitywnego. Rekonstruuje najważniejsze stanowiska i debaty w danym polu, od pierwszych publikacji na temat prac niematerialnych oraz postfordyzmu przez analizy kryzysu finansowego 2001 roku po najnowsze publikacje teoretyków i teoretyczek kapitalizmu kognitywnego. Systematyzuje rozproszone w debacie nad kapitalizmem kognitywnym analizy, od wzrastającej roli efektów zewnętrznych i renty we współczesnym kapitalizmie, przez przekształcenia intelektu powszechnego po wykształcenie się nowych form wartości i nowych mechanizmów jej akumulacji. To właśnie to ostatnie zagadnienie, nowe mechanizmy akumulacji wartości, stanowi główny problem, na którym skupia się artykuł. Ukazując funkcje kapitału finansowego w ukształtowaniu się kapitalizmu kognitywnego jako pewnego reżimu akumulacji, artykuł nie tylko analizuje kapitalizm kognitywny jako niestabilny reżim akumulacji, ale stara się w systematyczny sposób przedstawić sprzeczności tegoż reżimu akumulacji.

SI units in radiation protection

International Nuclear Information System (INIS)

Herrmann, D.

1976-10-01

In the field of radiation protection all hitherto used units for activity, activity concentrations, exposure, absorbed dose, and dose rates have to be replaced by SI units during the next years. For this purpose graphs and conversion tables are given as well as recommendations on unit combinations preferentially to be used. As to the dose equivalent, it is suggested to introduce a new special unit being 100 times greater than the rem, instead of maintaining the rem or using the gray for both absorbed dose and dose equivalent. Measures and time schedule relating to the gradual transition to SI units in measuring techniques, training, and publishing et cetera are explained. (author)

Malaria Treatment (United States)

Science.gov (United States)

... Providers, Emergency Consultations, and General Public. Contact Us Malaria Treatment (United States) Recommend on Facebook Tweet Share Compartir Treatment of Malaria: Guidelines For Clinicians (United States) Download PDF version ...

Matching soil grid unit resolutions with polygon unit scales for DNDC modelling of regional SOC pool

Science.gov (United States)

Zhang, H. D.; Yu, D. S.; Ni, Y. L.; Zhang, L. M.; Shi, X. Z.

2015-03-01

Matching soil grid unit resolution with polygon unit map scale is important to minimize uncertainty of regional soil organic carbon (SOC) pool simulation as their strong influences on the uncertainty. A series of soil grid units at varying cell sizes were derived from soil polygon units at the six map scales of 1:50 000 (C5), 1:200 000 (D2), 1:500 000 (P5), 1:1 000 000 (N1), 1:4 000 000 (N4) and 1:14 000 000 (N14), respectively, in the Tai lake region of China. Both format soil units were used for regional SOC pool simulation with DeNitrification-DeComposition (DNDC) process-based model, which runs span the time period 1982 to 2000 at the six map scales, respectively. Four indices, soil type number (STN) and area (AREA), average SOC density (ASOCD) and total SOC stocks (SOCS) of surface paddy soils simulated with the DNDC, were attributed from all these soil polygon and grid units, respectively. Subjecting to the four index values (IV) from the parent polygon units, the variation of an index value (VIV, %) from the grid units was used to assess its dataset accuracy and redundancy, which reflects uncertainty in the simulation of SOC. Optimal soil grid unit resolutions were generated and suggested for the DNDC simulation of regional SOC pool, matching with soil polygon units map scales, respectively. With the optimal raster resolution the soil grid units dataset can hold the same accuracy as its parent polygon units dataset without any redundancy, when VIV indices was assumed as criteria to the assessment. An quadratic curve regression model y = -8.0 × 10-6x2 + 0.228x + 0.211 (R2 = 0.9994, p < 0.05) was revealed, which describes the relationship between optimal soil grid unit resolution (y, km) and soil polygon unit map scale (1:x). The knowledge may serve for grid partitioning of regions focused on the investigation and simulation of SOC pool dynamics at certain map scale.

Freestanding midwifery unit versus obstetric unit

DEFF Research Database (Denmark)

Overgaard, Charlotte; Møller, Anna Margrethe; Fenger-Grøn, Morten

2011-01-01

low-risk women intending FMU birth and a matched control group of 839 low-risk women intending OU birth were included at the start of care in labour. OU women were individually chosen to match selected obstetric/socio-economic characteristics of FMU women. Analysis was by intention to treat. Main......Objective To compare perinatal and maternal morbidity and birth interventions in low-risk women giving birth in two freestanding midwifery units (FMUs) and two obstetric units (OUs). Design A cohort study with a matched control group. Setting The region of North Jutland, Denmark. Participants 839...... women were significantly less likely to experience an abnormal fetal heart rate (RR: 0.3, 95% CI 0.2 to 0.5), fetal–pelvic complications (0.2, 0.05 to 0.6), shoulder dystocia (0.3, 0.1 to 0.9), occipital–posterior presentation (0.5, 0.3 to 0.9) and postpartum haemorrhage >500 ml (0.4, 0.3 to 0...

Provision of bereavement care in neonatal units in the United Kingdom.

Science.gov (United States)

Robertson, Meredith J P; Aldridge, Anne; Curley, Anna E

2011-05-01

To establish what bereavement care services are available in neonatal units in the United Kingdom and to establish the availability to staff (doctors, nurses, and chaplains) of bereavement education, training, communication, and multicultural support. For families who lose a baby in the neonatal period, the support they receive from hospital staff can be pivotal in their ability to cope with their grief. Hospital staff are not always trained to provide this support. Limited evidence is available regarding hospital-based bereavement care in neonatology or its impact on outcome. Questionnaire survey of selected doctors, nurses, and chaplains in 200 neonatal units in the United Kingdom. We had responses from 100% of neonatal units surveyed. Of 600 individuals, 320 responded; 11% of doctors had never received any formal training in bereavement care, compared with 0.8% of nurses and 1.2% and chaplains. In addition, 31% of respondents thought the training they received was inadequate. Knowledge of grief theorists was poor. Up to 99% of units were helping parents create memories through photographs or handprints. Parents were uniformly given the chance to be with their baby at the time of death (99% overall). Siblings were encouraged to be present 71% of the time; 75% of respondents felt that information about the needs of different faith groups was available. Formal psychological support was offered to 45% of families after bereavement. Studies have shown that parents value clear communication, education about grieving, and demonstrated emotional support by staff. Our study has shown that there are deficiencies in staff training and education in this area. Educators must promote the inclusion of content on bereavement/end-of-life care. Additional education on cultural issues would be helpful. Managing the bereavement process well to minimize morbidity for families and healthcare providers is an important challenge for the future.

7 CFR 65.255 - United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false United States. 65.255 Section 65.255 Agriculture..., PEANUTS, AND GINSENG General Provisions Definitions § 65.255 United States. United States means the 50... United States. ...

Inlet Geomorphology Evolution Work Unit

Science.gov (United States)

2015-10-30

Coastal Inlets Research Program Inlet Geomorphology Evolution Work Unit The Inlet Geomorphology Evolution work unit of the CIRP develops methods...morphologic response. Presently, the primary tool of the Inlet Geomorphology Evolution work unit is the Sediment Mobility Tool (SMT), which allows the user

7 CFR 1150.106 - United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true United States. 1150.106 Section 1150.106 Agriculture... Order Definitions § 1150.106 United States. United States means the 48 contiguous States in the continental United States. ...

A functional intranet for the United States Coast Guard Unit

OpenAIRE

Hannah, Robert Todd.

1998-01-01

Approved for public release; distribution in unlimited. This thesis describes the complete development process of a friendly functional Intranet for an operational United States Coast Guard (USCG) electronic Support Unit (ESU) in Alameda, California. The final product is suitable for immediate use. It may also be used as a prototype for future Intranet development efforts. The methodology used to develop a finished, working product provides the core subject matter for this thesis. The disc...

NZG 201 portable spectrometric unit

International Nuclear Information System (INIS)

Jursa, P.; Novakova, O.; Slezak, V.

The NZG 201 spectrometric unit is a portable single-channel processing unit supplied from the mains or a battery which allows the qualitative and quantitative measurement of different types of ionizing radiation when connected to a suitable detection unit. The circuit layout and the choice of control elements makes the spectrometric unit suitable for use with scintillation detector units. The spectrometric unit consists of a pulse amplifier, an amplitude pulse analyzer, a pulse counter, a pulse rate counter with an output for a recorder, a high voltage source and a low voltage source. The block diagram is given. All circuits are modular and are mounted on PCB's. The apparatus is built in a steel cabinet with a raised edge which protects the control elements. The linear pulse amplifier has a maximum gain of 1024, the pulse counter has a maximum capacity of 10 6 -1 imp and time resolution better than 0.5 μs. The temperature interval at which the apparatus is operational is 0 to 45 degC, its weight is 12.5 kg and dimensions 36x280x310 mm, energy range O.025 to 2.5 MeV, for 137 Cs the energy resolution is 8 to 10%. The spectrometric unit NZG 2O1 may, with regard to its parameters, number and range of control elements, be used as a universal measuring unit. (J.P.)

Unit Cost Compendium Calculations

Data.gov (United States)

U.S. Environmental Protection Agency — The Unit Cost Compendium (UCC) Calculations raw data set was designed to provide for greater accuracy and consistency in the use of unit costs across the USEPA...

7 CFR 1212.31 - United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1212.31 Section 1212.31 Agriculture..., Consumer Education, and Industry Information Order Definitions § 1212.31 United States. “United States... territories and possessions of the United States. ...

Defense Science Board 1996 Summer Study Task Force On Tactics and Technology for 21st Century Military Superiority. Volume 2, Part 1. Supporting Materials

Science.gov (United States)

1996-10-01

static MTI/$AR oAutomatic target recognition o Fusion and integrated target tracking 21 3.2 Remote Precision Fires FIREPOWER Today * We use massive...support. * All galaxy sensors are netted plus organic sensors (VTOL, UGS) are required - Cell controls its own OPTEMPO; use sensors when they want with...ACTUATORS - HIGH DEFINITION VISIBLE / IR IMAGING o MINIATURE GPS / IMU - ACOUSTIC, SEISMIC, etc. * MINIATURE COMMUNICATIONS I - CHEM / BIO CONTROLS

Irans Foreign and Defense Policies

Science.gov (United States)

2016-12-21

buses, restaurants , and other civilian targets inside Israel. However, in 2012, their differing positions on the ongoing Syria conflict caused a rift...Uzbekistan (IMU).104 That group, which is active in Afghanistan, in mid-2015, declared its loyalty to the Islamic State organization.105 Almost all...natural gas customer . Perhaps in an attempt to diversify gas export routes, President Gurbanguly Berdymukhamedov signaled in 2007 that Turkmenistan

Comparison of robust H∞ filter and Kalman filter for initial alignment of inertial navigation system

Institute of Scientific and Technical Information of China (English)

HAO Yan-ling; CHEN Ming-hui; LI Liang-jun; XU Bo

2008-01-01

There are many filtering methods that can be used for the initial alignment of an integrated inertial navigation system.This paper discussed the use of GPS,but focused on two kinds of filters for the initial alignment of an integrated strapdown inertial navigation system (SINS).One method is based on the Kalman filter (KF),and the other is based on the robust filter.Simulation results showed that the filter provides a quick transient response and a little more accurate estimate than KF,given substantial process noise or unknown noise statistics.So the robust filter is an effective and useful method for initial alignment of SINS.This research should make the use of SINS more popular,and is also a step for further research.

7 CFR 1206.23 - United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1206.23 Section 1206.23 Agriculture... INFORMATION Mango Promotion, Research, and Information Order Definitions § 1206.23 United States. United... Rico, and the territories and possessions of the United States. ...

Flywheel and power unit

Energy Technology Data Exchange (ETDEWEB)

Seeley, R.W.

1992-10-28

A power unit, e.g. for an electrically driven vehicle, incorporates a flywheel for storing kinetic energy and a battery for storing electrical energy. The battery is incorporated as a substantial part of the rotating mass of the flywheel. Preferably the unit further includes an electrical machine being a motor or generator or machine operable either as a motor or a generator for transferring energy between the battery and the flywheel and/or for the input or output of rotary energy therefrom or thereto. The motor may be used for powering the flywheel and may also operate in a regenerative mode for recharging the unit on de-acceleration of the vehicle. The unit of the invention may also be utilized as an electrical stored power source, e.g. wind or water driven. (author)

Investigation and management of gastro-oesophageal reflux in United Kingdom neonatal intensive care units.

Science.gov (United States)

Rossor, Thomas; Andradi, Gwendolyn; Bhat, Ravindra; Greenough, Anne

2018-01-01

In 2004, wide variation in the investigation and management of gastro-oesophageal reflux (GOR) of infants on UK major neonatal units was demonstrated. Our aim was to resurvey neonatal practitioners to determine current practice and whether it was now evidence based. A questionnaire was sent to all 207 UK neonatal units. Responses were obtained from 84% of units. The most frequent 'investigation' was a trial of therapy (83% of units); pH studies were used in 38%, upper GI contrast studies in 19% and multichannel intraluminal impedance (MII)/pH studies in 5%. Only six units suggested a threshold for an abnormal pH study and two units for an abnormal MII study. Infants were commenced on antireflux medication without investigation always in 32% of units, often in 29%, occasionally in 19% and only never in 1%. Gaviscon was used as first line treatment in 60% of units, and other medications included ranitidine in 53%, thickening agents in 27%, proton pump inhibitors in 23%, domperidone in 22% and erythromycin in 6%. There remains a wide variation in diagnostic and treatment strategies for infants with suspected GOR on neonatal intensive care units, emphasising the need for randomised trials to determine appropriate GOR management. ©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Associations among unit leadership and unit climates for implementation in acute care: a cross-sectional study.

Science.gov (United States)

Shuman, Clayton J; Liu, Xuefeng; Aebersold, Michelle L; Tschannen, Dana; Banaszak-Holl, Jane; Titler, Marita G

2018-04-25

Nurse managers have a pivotal role in fostering unit climates supportive of implementing evidence-based practices (EBPs) in care delivery. EBP leadership behaviors and competencies of nurse managers and their impact on practice climates are widely overlooked in implementation science. The purpose of this study was to examine the contributions of nurse manager EBP leadership behaviors and nurse manager EBP competencies in explaining unit climates for EBP implementation in adult medical-surgical units. A multi-site, multi-unit cross-sectional research design was used to recruit the sample of 24 nurse managers and 553 randomly selected staff nurses from 24 adult medical-surgical units from 7 acute care hospitals in the Northeast and Midwestern USA. Staff nurse perceptions of nurse manager EBP leadership behaviors and unit climates for EBP implementation were measured using the Implementation Leadership Scale and Implementation Climate Scale, respectively. EBP competencies of nurse managers were measured using the Nurse Manager EBP Competency Scale. Participants were emailed a link to an electronic questionnaire and asked to respond within 1 month. The contributions of nurse manager EBP leadership behaviors and competencies in explaining unit climates for EBP implementation were estimated using mixed-effects models controlling for nurse education and years of experience on current unit and accounting for the variability across hospitals and units. Significance level was set at α < .05. Two hundred sixty-four staff nurses and 22 nurse managers were included in the final sample, representing 22 units in 7 hospitals. Nurse manager EBP leadership behaviors (p < .001) and EBP competency (p = .008) explained 52.4% of marginal variance in unit climate for EBP implementation. Leadership behaviors uniquely explained 45.2% variance. The variance accounted for by the random intercepts for hospitals and units (p < .001) and years of nursing experience in current unit

IMPLEMENTATION OF A REAL-TIME STACKING ALGORITHM IN A PHOTOGRAMMETRIC DIGITAL CAMERA FOR UAVS

Directory of Open Access Journals (Sweden)

A. Audi

2017-08-01

Full Text Available In the recent years, unmanned aerial vehicles (UAVs have become an interesting tool in aerial photography and photogrammetry activities. In this context, some applications (like cloudy sky surveys, narrow-spectral imagery and night-vision imagery need a longexposure time where one of the main problems is the motion blur caused by the erratic camera movements during image acquisition. This paper describes an automatic real-time stacking algorithm which produces a high photogrammetric quality final composite image with an equivalent long-exposure time using several images acquired with short-exposure times. Our method is inspired by feature-based image registration technique. The algorithm is implemented on the light-weight IGN camera, which has an IMU sensor and a SoC/FPGA. To obtain the correct parameters for the resampling of images, the presented method accurately estimates the geometrical relation between the first and the Nth image, taking into account the internal parameters and the distortion of the camera. Features are detected in the first image by the FAST detector, than homologous points on other images are obtained by template matching aided by the IMU sensors. The SoC/FPGA in the camera is used to speed up time-consuming parts of the algorithm such as features detection and images resampling in order to achieve a real-time performance as we want to write only the resulting final image to save bandwidth on the storage device. The paper includes a detailed description of the implemented algorithm, resource usage summary, resulting processing time, resulting images, as well as block diagrams of the described architecture. The resulting stacked image obtained on real surveys doesn’t seem visually impaired. Timing results demonstrate that our algorithm can be used in real-time since its processing time is less than the writing time of an image in the storage device. An interesting by-product of this algorithm is the 3D rotation

United Nations opens gender coordinating unit for Afghanistan.

Science.gov (United States)

Morris, K

1999-02-06

The UN has created a gender coordinating unit for Afghanistan in an effort to combat some problems encountered by women and girls in the country. Reports continue to come in of women in Afghanistan being denied the right to work, to be educated, and to have access to medical care. The gap in education between men and women continues to widen as a result of edicts issued by Taliban authorities banning girls from attending formal schools and female teachers from working. The situation has grown worse since the UN and nongovernmental organizations (NGOs) withdrew international workers last year due to security concerns. Although a UN mission will travel to the country this week to discuss the return of international staff, the gender coordinating unit will for now have to work out of Islamabad, Pakistan. The unit will create guidelines for gender mainstreaming, a strategy in which mainstream policies and resource allocations are changed to reflect the principle of gender equality. Other goals include setting realistic objectives for gender activities, working with partners on pilot projects, and establishing minimum standards for best practices. MERLIN, a NGO with a primary health care program run by local staff in the Taliban-controlled province of Farah, welcomes the move.

Functional unit for a processor

NARCIS (Netherlands)

Rohani, A.; Kerkhoff, Hans G.

2013-01-01

The invention relates to a functional unit for a processor, such as a Very Large Instruction Word Processor. The invention further relates to a processor comprising at least one such functional unit. The invention further relates to a functional unit and processor capable of mitigating the effect of

Smart Rocking Armour Units

OpenAIRE

Hofland, B.; Arefin, Syed Shamsil; van der Lem, Cock; van gent, Marcel

2018-01-01

This paper describes a method to measure the rocking motion of lab-scale armour units. Sensors as found in mobile phones are used. These sensors, data-storage and battery are all embedded in the model units, such that they can be applied without wires attached to them. The technique is applied to double-layer units in order to compare the results to the existing knowledge for this type of armour layers. In contrast to previous research, the gyroscope reading is used to determine the (rocking)...

7 CFR 1250.308 - United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1250.308 Section 1250.308 Agriculture... Research and Promotion Order Definitions § 1250.308 United States. United States means the 48 contiguous States of the United States of America and the District of Columbia. ...

7 CFR 1205.23 - United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1205.23 Section 1205.23 Agriculture... Procedures for Conduct of Sign-up Period Definitions § 1205.23 United States. The term United States means the 50 states of the United States of America. Procedures ...

United States housing, 2012

Science.gov (United States)

Delton Alderman

2013-01-01

Provides current and historical information on housing market in the United States. Information includes trends for housing permits and starts, housing completions for single and multifamily units, and sales and construction. This report will be updated annually.

Mechanical strainer unit

International Nuclear Information System (INIS)

Kraeling, J.B.; Netkowicz, R.J.; Schnall, I.H.

1983-01-01

The mechanical strainer unit is connected to a flanged conduit which originates in and extends out of a suppression chamber in a nuclear reactor. The strainer includes a plurality of centrally apertured plates positioned along a common central axis and in parallel and spaced relationship. The plates have a plurality of bores radially spaced about the central axis. Spacer means such as washers are positioned between adjacent plates to maintain the plates is spaced relationship and form communicating passages of a predetermined size to the central apertures. Connecting means such as bolts or studs extend through the aligned bores to maintain the unit in assembled relationship and secure the unit to the pipe. By employing perforated plates and blocking off certain of the communicating passages, a dual straining effect can be achieved

Snakes: An Integrated Unit Plan.

Science.gov (United States)

Lawrence, Lisa

This document presents an integrated unit plan on snakes targeting second grade students. Objectives of the unit include developing concepts of living things, understanding the contribution and importance of snakes to the environment, and making connections between different disciplines. The unit integrates the topic of snakes into the areas of…

The effects of unit morale and interpersonal relations on conflict in the nursing unit.

Science.gov (United States)

Cox, K B

2001-07-01

Health care organizations face major changes, and these changes are likely to increase conflict in organizations. Although numerous studies have focused on conflict management, few have considered causes and effect of conflict in nursing units. The investigation tested a structural equation that examined the relationships among individual and contextual variables and intragroup conflict, job satisfaction, team performance effectiveness, and anticipated turnover. The nonrandom sample consisted of 141 nurses employed on 13 inpatient units at a state-supported, 597-bed academic medical centre in a southeastern city. Intragroup conflict was higher on smaller units with a higher ratio of RNs to total staff. Intragroup conflict was not associated with satisfaction with pay or anticipated turnover. In the final model, the unit morale and interpersonal relations dimension of team performance effectiveness was negatively associated with intragroup conflict and anticipated turnover, and positively associated with satisfaction with pay. High perceptions of unit morale and interpersonal relations buffered the effect of unit size and skill mix on intragroup conflict. Goodness of fit statistics indicated a good fit of the model to data. The findings have implications for nursing educators and administrators, and provide direction for future research.

Grandeurs, dimensions, et conversions d'unités Quantities, Dimensions and Units Conversions

Directory of Open Access Journals (Sweden)

Bronner C.

2006-11-01

Full Text Available Il n'est plus besoin de démontrer que le Système International d'Unités (SI est un fait. Il est normalement enseigné dans les lycées et universités. Les scientifiques l'utilisent systématiquement dans leurs publications; les nouveaux livres et banques de données s'en servent couramment. Cependant, certaines industries (la pétrolière entre autres continuent à se servir de systèmes techniques. On trouve dans des archives de vieilles données ou des spécifications d'usines qui ont été faites dans d'autres systèmes. Il n'est pas rare, dans la vie professionnelle, de rencontrer un problème où une unité doit être transformée. Cet article souhaite aider les personnes qui doivent résoudre ce genre d'écueil en leur présentant une vision globale des différents systèmes d'unités qui ont historiquement existé. Une définition des unités, soit traditionnelles, soit étranges, accompagne également l'article. L'aide la plus importante sera sans doute trouvée dans le programme inclus dans une disquette. Un logiciel complet, sous Windows, permettra à quiconque de résoudre, sans erreur, son problème de conversion d'unité. La technique de conversion, basée sur l'utilisation du calcul dimensionnel, et utilisée dans le programme, est également expliquée. It is not longer necessary to prove that the International System of Units (SI is a fact. It is normally used in schools and universities. Scientists systematically use SI in their publications. New books and databases are commonly built on it. Meanwhile, some industries (oil companies among others keep on using technical systems. It is possible to find old data and plant designs that use other systems. It is not uncommon, in professional life, to find a problem in which units need to be transformed. This article aims to help people who have to solve this kind of difficulty, by giving an overview of the different unit systems. A description of traditional and unusual units is

31 CFR 542.310 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 542.310 Section 542.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF....310 United States. The term United States means the United States, its territories and possessions...

31 CFR 548.310 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 548.310 Section 548.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF....310 United States. The term United States means the United States, its territories and possessions...

31 CFR 546.310 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 546.310 Section 546.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF....310 United States. The term United States means the United States, its territories and possessions...

31 CFR 586.318 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 586.318 Section 586...) KOSOVO SANCTIONS REGULATIONS General Definitions § 586.318 United States. The term United States means the United States, its territories and possessions, and all areas under the jurisdiction or authority...

31 CFR 537.318 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 537.318 Section 537.318 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF....318 United States. The term United States means the United States, its territories and possessions...

31 CFR 597.318 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 597.318 Section 597... General Definitions § 597.318 United States. The term United States means the United States, its territories, states, commonwealths, districts, and possessions, and all areas under the jurisdiction or...

31 CFR 585.316 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 585.316 Section 585.316 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... General Definitions § 585.316 United States. The term United States means the United States, its...

31 CFR 575.319 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 575.319 Section 575.319 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF....319 United States. The term United States means the United States, its territories and possessions...

31 CFR 539.312 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 539.312 Section 539.312 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... General Definitions § 539.312 United States. The term United States means the United States, its...

31 CFR 551.309 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 551.309 Section 551.309 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF....309 United States. The term United States means the United States, its territories and possessions...

7 CFR 1219.26 - United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1219.26 Section 1219.26 Agriculture..., AND INFORMATION Hass Avocado Promotion, Research, and Information Order Definitions § 1219.26 United States. United States means collectively the several 50 States of the United States, the District of...

31 CFR 587.310 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 587.310 Section 587...) MILOSEVIC SANCTIONS REGULATIONS General Definitions § 587.310 United States. The term United States means the United States, its territories and possessions, and all areas under the jurisdiction or authority...

31 CFR 547.310 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 547.310 Section 547.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... General Definitions § 547.310 United States. The term United States means the United States, its...

Design of hydraulic recuperation unit

Directory of Open Access Journals (Sweden)

Jandourek Pavel

2016-01-01

Full Text Available This article deals with design and measurement of hydraulic recuperation unit. Recuperation unit consist of radial turbine and axial pump, which are coupled on the same shaft. Speed of shaft with impellers are 6000 1/min. For economic reasons, is design of recuperation unit performed using commercially manufactured propellers.

31 CFR 598.317 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 598.317 Section 598.317 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... Definitions § 598.317 United States. The term United States means the United States, its territories and...

31 CFR 596.312 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 596.312 Section 596.312 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... General Definitions § 596.312 United States. The term United States means the United States, including its...

31 CFR 538.314 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 538.314 Section 538.314 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... § 538.314 United States. The term United States means the United States, its territories and possessions...

31 CFR 543.310 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 543.310 Section 543.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... Definitions § 543.310 United States. The term United States means the United States, its territories and...

31 CFR 594.313 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 594.313 Section 594.313 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... Definitions § 594.313 United States. The term United States means the United States, its territories and...

31 CFR 588.310 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 588.310 Section 588.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... Definitions § 588.310 United States. The term United States means the United States, its territories and...

31 CFR 536.315 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 536.315 Section 536.315 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... Definitions § 536.315 United States. The term United States means the United States, its territories and...

31 CFR 544.310 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 544.310 Section 544.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... REGULATIONS General Definitions § 544.310 United States. The term United States means the United States, its...

31 CFR 545.313 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 545.313 Section 545.313 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... Definitions § 545.313 United States. The term United States means the United States, its territories and...

31 CFR 595.314 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 595.314 Section 595.314 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... § 595.314 United States. The term United States means the United States, its territories and possessions...

31 CFR 560.307 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 560.307 Section 560.307 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... § 560.307 United States. The term United States means the United States, including its territories and...

31 CFR 593.311 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 593.311 Section 593.311 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... REGULATIONS General Definitions § 593.311 United States. The term United States means the United States, its...

31 CFR 541.310 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 541.310 Section 541.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... § 541.310 United States. The term United States means the United States, its territories and possessions...

22 CFR 120.13 - United States.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false United States. 120.13 Section 120.13 Foreign... United States. United States, when used in the geographical sense, includes the several states, the Commonwealth of Puerto Rico, the insular possessions of the United States, the District of Columbia, the...

31 CFR 540.313 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 540.313 Section 540.313 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... REGULATIONS General Definitions § 540.313 United States. The term United States means the United States, its...

Hanford Site Waste Management Units Report

International Nuclear Information System (INIS)

1991-01-01

This Hanford Site Waste Management Units Report (HSWMUR) was originated to provide information responsive to Section 3004(u) of the Hazardous and Solid Waste Amendments (HSWA) of the 1984 United States Code (USC). The report provides a comprehensive inventory of all types of waste management units at the Hanford Site and consists of waste disposal units, including (1) Resource Conservation and Recovery Act of 1976 (RCRA) disposal units, (2) Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) disposal units, (3) unplanned releases, (4) inactive contaminated structure, (5) RCRA treatment and storage units, and (6) other storage areas. Because of the comprehensive nature of this report, the listing of sites is more extensive than required by Section 3004(u) of HSWA. In support of the Hanford RCRA permit, a field was added to designate whether the waste management unit is a solid waste management unit (SWMU). As SWMUs are identified, they will added to the Hanford Waste Information Data System (WIDS), which is the database supporting this report, and added to the report at its next annual update. A quality review of the WIDS was conducted this past year. The review included checking all data against their reference and making appropriate changes, updating the data elements using the most recent references, marking duplicate units for deletion, and addition additional information. 6 refs

Hanford Site Waste Management Units Report

International Nuclear Information System (INIS)

1991-01-01

This Hanford Site Waste Management Units Report (HSWMUR) was originated to provide information responsive to Section 3004(u) of the Hazardous and Solid Waste Amendments (HSWA) of the 1984 United States Code (USC). The report provides a comprehensive inventory of all types of waste management units at the Hanford Site and consists of waste disposal units, including (1) Resource Conservation and Recovery Act of 1976 (RCRA) disposal units, (2) Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) disposal units, (3) unplanned releases, (4) inactive contaminated structures, (5) RCRA treatment and storage units, and (6) other storage areas. Because of the comprehensive nature of this report, the listing of sites is more extensive than required by Section 3004(u) of HSWA. In support of the Hanford RCRA permit, a field was added to designate whether the waste management unit is a solid waste management unit (SWMU). As SWMUs are identified, they will added to the Hanford Waste Information Data System (WIDS), which is the database supporting this report, and added to the report at its next annual update. A quality review of the WIDS was conducted this past year. The review included checking all data against their reference and making appropriate changes, updating the data elements using the most recent references, marking duplicate units for deletion, and adding additional information. 6 refs

The Auto Industry. Grade Nine. Resource Unit (Unit IV). Project Social Studies.

Science.gov (United States)

Minnesota Univ., Minneapolis. Project Social Studies Curriculum Center.

Unit four of this curriculum plan for ninth grade social studies outlines a study of the automobile industry in the United States. Objectives state the desired generalizations, skills, and attitudes to be developed. A condensed outline of course content precedes expanded guidelines for teaching procedures and suggested resource materials. A…

31 CFR 592.311 - United States.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States. 592.311 Section 592... § 592.311 United States. The term United States, when used in the geographic sense, means the several States, the District of Columbia, and any commonwealth, territory, or possession of the United States. ...

Waste management units - Savannah River Site

International Nuclear Information System (INIS)

1989-10-01

This report is a compilation of worksheets from the waste management units of Savannah River Plant. Information is presented on the following: Solid Waste Management Units having received hazardous waste or hazardous constituents with a known release to the environment; Solid Waste Management Units having received hazardous waste or hazardous constituents with no known release to the environment; Solid Waste Management Units having received no hazardous waste or hazardous constituents; Waste Management Units having received source; and special nuclear, or byproduct material only

7 CFR 1205.313 - United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1205.313 Section 1205.313 Agriculture... Research and Promotion Order Definitions § 1205.313 United States. United States means the 50 States of the United States of America. [31 FR 16758, Dec. 31, 1966. Redesignated at 56 FR 64472, Dec. 10, 1991] ...

History of United States Energy. A Basic Teaching Unit on Energy. Revised.

Science.gov (United States)

McDermott, Hugh, Ed.; Scharmann, Larry, Ed.

Intended as a supplement to the units "Oil: Fuel of the Past" and "Coal: Fuel of the Past, Hope of the Future," this 3-4 day unit contains three activities which briefly explain the chronological development of energy resources and the formation and development of the Organization of Petroleum Exporting Countries (OPEC). The…

Generating units performances: power system requirements

Energy Technology Data Exchange (ETDEWEB)

Fourment, C; Girard, N; Lefebvre, H

1994-08-01

The part of generating units within the power system is more than providing power and energy. Their performance are not only measured by their energy efficiency and availability. Namely, there is a strong interaction between the generating units and the power system. The units are essential components of the system: for a given load profile the frequency variation follows directly from the behaviour of the units and their ability to adapt their power output. In the same way, the voltage at the units terminals are the key points to which the voltage profile at each node of the network is linked through the active and especially the reactive power flows. Therefore, the customer will experience the frequency and voltage variations induced by the units behaviour. Moreover, in case of adverse conditions, if the units do not operate as well as expected or trip, a portion of the system, may be the whole system, may collapse. The limitation of the performance of a unit has two kinds of consequences. Firstly, it may result in an increased amount of not supplied energy or loss of load probability: for example if the primary reserve is not sufficient, a generator tripping may lead to an abnormal frequency deviation, and load may have to be shed to restore the balance. Secondly, the limitation of a unit performance results in an economic over-cost for the system: for instance, if not enough `cheap` units are able to load-following, other units with higher operating costs have to be started up. We would like to stress the interest for the operators and design teams of the units on the one hand, and the operators and design teams of the system on the other hand, of dialog and information exchange, in operation but also at the conception stage, in order to find a satisfactory compromise between the system requirements and the consequences for the generating units. (authors). 11 refs., 4 figs.

Racial Conflict in the United States: What Should Be Done? Grade Twelve. [Resource Unit V.] Project Social Studies.

Science.gov (United States)

Minnesota Univ., Minneapolis. Project Social Studies Curriculum Center.

This is the fifth of seven resource units for a twelfth grade course on value conflicts and policy decisions. The topic for this unit is racial conflict in the United States. The introduction explains how this unit coincides with other units of the K-12 series which have treated intergroup relations. The objectives are listed as to…

Dependence of the paired motor unit analysis on motor unit discharge characteristics in the human tibialis anterior muscle

Science.gov (United States)

Stephenson, Jennifer L.; Maluf, Katrina S.

2011-01-01

The paired motor unit analysis provides in vivo estimates of the magnitude of persistent inward currents (PIC) in human motoneurons by quantifying changes in the firing rate (ΔF) of an earlier recruited (reference) motor unit at the time of recruitment and derecruitment of a later recruited (test) motor unit. This study assessed the variability of ΔF estimates, and quantified the dependence of ΔF on the discharge characteristics of the motor units selected for analysis. ΔF was calculated for 158 pairs of motor units recorded from nine healthy individuals during repeated submaximal contractions of the tibialis anterior muscle. The mean (SD) ΔF was 3.7 (2.5) pps (range −4.2 to 8.9 pps). The median absolute difference in ΔF for the same motor unit pair across trials was 1.8 pps, and the minimal detectable change in ΔF required to exceed measurement error was 4.8 pps. ΔF was positively related to the amount of discharge rate modulation in the reference motor unit (r2=0.335; Precruitment of the reference and test motor units (r2=0.229, Pmotor unit activity (r2=0.110, Precruitment threshold of the test motor unit (r2=0.237, Pmotor unit analysis. PMID:21459110

Units Based on Constants: The Redefinition of the International System of Units

Science.gov (United States)

Stenger, J.; Ullrich, J. H.

2016-03-01

Recent decisions of the General Conference on Weights and Measures of the Metre Convention have opened the door to a fundamental change of the International System of Units, the SI, in 2018. The revised SI will be based on fixing the numerical values of seven defining constants corresponding to the seven traditional base units. This will bring about basic modifications in the definition of the kilogram, the ampere, the kelvin, and the mole and will have consequences for units derived from them. In contrast, the second, the meter, and the candela will not be affected. This paper describes the motivation and rationale behind this endeavor, introduces the new definitions, and reviews the requirements for the redefinitions as well as the status of the experiments that are currently being carried out to fulfill them. Benefits and a wide-reaching impact for the realization and dissemination of the units are anticipated because innovative technologies with ever-increasing accuracy will emerge, enabling the direct realization over widespread measurement ranges without the definitions themselves having to be changed.

Generating Units

Data.gov (United States)

Department of Homeland Security — Generating Units are any combination of physically connected generators, reactors, boilers, combustion turbines, and other prime movers operated together to produce...

Intelligent multi-unit disk controller

International Nuclear Information System (INIS)

Poirot, Lucien

1982-01-01

This controller has been designed as a link between a 16 bits minicomputer and two types of disks units interface: the SMD interface and an equivalent to the DRI unit interface. Four units of each type can be handled by the controller. A bit slice microprocessor controls the interface with the disks units. The maximum exchange rate is 8 megabits per second. A CRC feature has been provided for error detection. A 16 bits microprocessor implements the interface to the computer, assuring head positioning, the management of bad tracks, as well as the supervision of each transfer. A internal buffer memory allows an asynchronous dialogue with the computer. The implementation of the controller makes easy the adaptation to disks units of various types, and though it has been initially intended for a minicomputer of the MITRA type, its microprocessor based design makes it fitted to any minicomputer. (author) [fr

Vision Aided Inertial Navigation System Augmented with a Coded Aperture

Science.gov (United States)

2011-03-24

GPS IMU INS LlDAR MAV MITE OTF PDF PSD PSF PVA SIFT SLAM List of Abbreviations Description Two Dimensional Three Dimensional Four...mapping ( SLAM ) [31]. A single image from a traditional camera provides heading information from the camera to a landmark, constraining the possible...through use of light detection and ranging ( LIDAR ) [3]. Laser range scanners emit light in a given direction and measure properties of the light

Improving the Performance of MEMS GYROS via Redundant Measurements: Theory and Experiments

Science.gov (United States)

2014-12-01

PC via a USB-micro-USB connector ................................46 Figure 28 Arduino serial port monitor displaying the default menu screen for the...done by specific pieces of hardware. 12*9-DOF Sensor Array Computer Wired / Wireless Router Arduino Software Upload Displayed on Host PC Real...a total of nine axes of measurement on the IMU. The integration software included on the sensors Arduino board incorporates data from all nine axes

The United Kingdom: Issues for the United States

National Research Council Canada - National Science Library

Archick, Kristin

2007-01-01

...; and more recently, from the UK's strong support in countering terrorism and confronting Iraq. The United States and Britain also share a mutually beneficial trade and economic relationship, and are each other's biggest foreign direct investors...

Legitimita demokratického režimu a jeho efektivita

Czech Academy of Sciences Publication Activity Database

Šafr, Jiří

2005-01-01

Roč. 3, 1-2 (2005), s. 21-23 ISSN 1214-1720 Institutional research plan: CEZ:AV0Z70280505 Keywords : Legitimacy * democracy * M. S. Lipset Subject RIV: AO - Sociology, Demography http://www.socioweb.cz

Small satellite attitude determination based on GPS/IMU data fusion

Energy Technology Data Exchange (ETDEWEB)

Golovan, Andrey [Navigation and Control Laboratory, M.V. Lomonosov Moscow State University, GSP-1, Leninskie Gory, Moscow (Russian Federation); Cepe, Ali [Department of Applied Mechanics and Control, M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

2014-12-10

In this paper, we present the mathematical models and algorithms that describe the problem of attitude determination for a small satellite using measurements from three angular rate sensors (ARS) and aiding measurements from multiple GPS receivers/antennas rigidly attached to the platform of the satellite.

Measurement units of physical values; Unites de mesure des grandeurs physiques

Energy Technology Data Exchange (ETDEWEB)

Debraine, P [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

1955-07-01

The aim of this paper is twofold: 1) to give an analysis of the formation conditions of the various systems of units, 2) to show how the practical problems involving changes of units can be solved. This analysis leads to the conception of 'types' of systems, which is very useful to clarity the question of rationalized and non rationalized systems. The second point which consists essentially in: 1) finding the relationship between the measures of a given quantity in different systems, 2) deriving practical formulas, 3) deriving formulas in various 'types' of systems, is made easier by use of sets of: * definition formulas, * transformation formulas, * units of the various practical systems with useful numerical information covering the following fields: ** geometry, ** kinematics, ** mechanics, ** electricity and magnetism, ** thermodynamics, ** radiation, ** photometry, These sets being printed on coloured paper can be easily found. A number of numerical examples (21) show in a detailed way how to solve the various problems likely to occur. A chapter is particularly devoted to the Giorgi MKS system. (author) [French] Le but de cet expose est double: 1) donner une analyse des conditions de formation des differents systemes d'unites, 2) montrer comment peuvent se resoudre les problemes pratiques de changement d'unites. Cette analyse amene a 1a conception de ''types'' de systemes, conception tres utile pour eclairer la question des systemes rationalises et non rationalises. La seconde partie du programme qui consiste essentiellement: 1) a determiner les relations entre les mesures d'une meme grandeur dans differents systemes, 2) a etablir des formules pratiques, 3) a etablir les formules valables dans un ''type'' de systeme donne est facilitee par l'utilisation de listes classees de 1) formules de definition, 2) equations de transformation, 3) unites des differents systemes accompagnees de relations numeriques utiles, couvrant les domaines suivants: 1) geometrie, 5

Anti-Terrorism Authority Under the Laws of the United Kingdom and the United States

National Research Council Canada - National Science Library

Feikert, Clare; Doyle, Charles

2006-01-01

This is a comparison of the laws of the United Kingdom and of the United States that govern criminal and intelligence investigations of terrorist activities Both systems rely upon a series of statutory authorizations...

Use of Internet Search Data to Monitor Rotavirus Vaccine Impact in the United States, United Kingdom, and Mexico.

Science.gov (United States)

Shah, Minesh P; Lopman, Benjamin A; Tate, Jacqueline E; Harris, John; Esparza-Aguilar, Marcelino; Sanchez-Uribe, Edgar; Richardson, Vesta; Steiner, Claudia A; Parashar, Umesh D

2018-02-19

Previous studies have found a strong correlation between internet search and public health surveillance data. Less is known about how search data respond to public health interventions, such as vaccination, and the consistency of responses in different countries. In this study, we aimed to study the correlation between internet searches for "rotavirus" and rotavirus disease activity in the United States, United Kingdom, and Mexico before and after introduction of rotavirus vaccine. We compared time series of internet searches for "rotavirus" from Google Trends with rotavirus laboratory reports from the United States and United Kingdom and with hospitalizations for acute gastroenteritis in the United States and Mexico. Using time and location parameters, Google quantifies an internet query share (IQS) to measure the relative search volume for specific terms. We analyzed the correlation between IQS and laboratory and hospitalization data before and after national vaccine introductions. There was a strong positive correlation between the rotavirus IQS and laboratory reports in the United States (R2 = 0.79) and United Kingdom (R2 = 0.60) and between the rotavirus IQS and acute gastroenteritis hospitalizations in the United States (R2 = 0.87) and Mexico (R2 = 0.69) (P United States and by 70% (95% CI, 55%-86%) in Mexico. In the United Kingdom, there was a loss of seasonal variation after vaccine introduction. Rotavirus internet search data trends mirrored national rotavirus laboratory trends in the United States and United Kingdom and gastroenteritis-hospitalization data in the United States and Mexico; lower correlations were found after rotavirus vaccine introduction. Published by Oxford University Press on behalf of The Journal of the Pediatric Infectious Diseases Society 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

United Nations Peacekeeping: Issues for Congress

National Research Council Canada - National Science Library

Browne, Marjorie A

2008-01-01

A major issue facing the United Nations, the United States, and the 110th Congress is the extent to which the United Nations has the capacity to restore or keep the peace in the changing world environment...

United Nations Peacekeeping: Issues for Congress

National Research Council Canada - National Science Library

Browne, Marjorie A

2007-01-01

A major issue facing the United Nations, the United States, and the 110th Congress is the extent to which the United Nations has the capacity to restore or keep the peace in the changing world environment...

Qualification of package units; Qualifizierung von Package Units

Energy Technology Data Exchange (ETDEWEB)

Brombacher, M.; Walter, U. [Bayer AG, Leverkusen (Germany)

1999-07-01

The use of package units in pharmaceutical plants is increasing. If they are involved in the manufacture of pharmaceuticals and have an influence on the quality of the end product, the user is required to validate the processes used. Parallel to the growing demands with respect to the automation of these units, the importance of PCS equipment has increased and with this the necessity for its qualification. Experience to date shows that the manufacturer's awareness of these requirements can be heightened still further. This paper describes approaches for improving the present situation and should be interpreted not as criticism but as providing an opportunity to increase the knowledge base and work together to define solutions which satisfy the guidelines. (orig.) [German] Der Einsatz von Package Units in Pharma-Anlagen erfaehrt zunehmende Verbreitung. Wenn sie an der Herstellung von Arzneimitteln beteiligt sind und auf die Qualitaet des Endprodukts Einfluss nehmen, unterliegen sie der Validierungspflicht, die der Anwender zu gewaehrleisten hat. Entsprechend den wachsenden Anforderungen an die Automatisierung dieser Einheiten ist auch der Stellenwert der PLT-Ausruestung angestiegen und mit ihm die Notwendigkeit von deren Qualifizierung. Die bisherige Praxis zeigt, dass die Sensbilitaet der Hersteller diesen Anforderungen gegenueber noch besser entwickelt werden kann. Der Beitrag zeigt Wege auf, um die derzeitige Situation zu verbessern und sollte nicht als Kritik sondern als Chance aufgefasst werden, den Wissensstand auszugleichen und gemeinsam zu richtliniengerechten Loesungen zu kommen. (orig.)

Equilibrium Selection with Risk Dominance in a Multiple-unit Unit Uniform Price Auction

DEFF Research Database (Denmark)

Boom, Anette

This paper uses an adapted version of the linear tracing procedure, suggested by Harsanyi and Selten (1988), in order to discriminate between two types of multiple Nash equilibria. Equilibria of the same type are pay-off equivalent in the analysed multiple-unit unit price auction where two seller...

Neighbors United for Health

Science.gov (United States)

Westhoff, Wayne W.; Corvin, Jaime; Virella, Irmarie

2009-01-01

Modeled upon the ecclesiastic community group concept of Latin America to unite and strengthen the bond between the Church and neighborhoods, a community-based organization created Vecinos Unidos por la Salud (Neighbors United for Health) to bring health messages into urban Latino neighborhoods. The model is based on five tenants, and incorporates…

Smart Rocking Armour Units

NARCIS (Netherlands)

Hofland, B.; Arefin, Syed Shamsil; van der Lem, Cock; van gent, Marcel

2018-01-01

This paper describes a method to measure the rocking motion of lab-scale armour units. Sensors as found in mobile phones are used. These sensors, data-storage and battery are all embedded in the model units, such that they can be applied without wires attached to them. The technique is applied to

The instrument control unit of SPICA SAFARI: a macro-unit to host all the digital control functionalities of the spectrometer

Science.gov (United States)

Di Giorgio, Anna Maria; Biondi, David; Saggin, Bortolino; Shatalina, Irina; Viterbini, Maurizio; Giusi, Giovanni; Liu, Scige J.; Cerulli-Irelli, Paquale; Van Loon, Dennis; Cara, Christophe

2012-09-01

We present the preliminary design of the Instrument Control Unit (ICU) of the SpicA FAR infrared Instrument (SAFARI), an imaging Fourier Transform Spectrometer (FTS) designed to give continuous wavelength coverage in both photometric and spectroscopic modes from around 34 to 210 µm. Due to the stringent requirements in terms of mass and volume, the overall SAFARI warm electronics will be composed by only two main units: Detector Control Unit and ICU. ICU is therefore a macro-unit incorporating the four digital sub-units dedicated to the control of the overall instrument functionalities: the Cooler Control Unit, the Mechanism Control Unit, the Digital processing Unit and the Power Supply Unit. Both the mechanical solution adopted to host the four sub-units and the internal electrical architecture are presented as well as the adopted redundancy approach.

Inching toward incrementalism: federalism, devolution, and health policy in the United States and the United Kingdom.

Science.gov (United States)

Sparer, Michael S; France, George; Clinton, Chelsea

2011-02-01

In the United States, the recently enacted Patient Protection and Affordable Care Act of 2010 envisions a significant increase in federal oversight over the nation's health care system. At the same time, however, the legislation requires the states to play key roles in every aspect of the reform agenda (such as expanding Medicaid programs, creating insurance exchanges, and working with providers on delivery system reforms). The complicated intergovernmental partnerships that govern the nation's fragmented and decentralized system are likely to continue, albeit with greater federal oversight and control. But what about intergovernmental relations in the United Kingdom? What impact did the formal devolution of power in 1999 to Scotland, Wales, and Northern Ireland have on health policy in those nations, and in the United Kingdom more generally? Has devolution begun a political process in which health policy in the United Kingdom will, over time, become increasingly decentralized and fragmented, or will this "state of unions" retain its long-standing reputation as perhaps the most centralized of the European nations? In this article, we explore the federalist and intergovernmental implications of recent reforms in the United States and the United Kingdom, and we put forward the argument that political fragmentation (long-standing in the United States and just emerging in the United Kingdom) produces new intergovernmental partnerships that, in turn, produce incremental growth in overall government involvement in the health care arena. This is the impact of what can be called catalytic federalism.

Fatigue in Breakwater Concrete Armour Units

DEFF Research Database (Denmark)

Burcharth, Hans F.

The reliability of rubble mound breakwaters depends on the hydraulic stability and the mechanical strength of the armour units. The paper deals with the important aspect of fatigue related to the strength of concrete armour units.......The reliability of rubble mound breakwaters depends on the hydraulic stability and the mechanical strength of the armour units. The paper deals with the important aspect of fatigue related to the strength of concrete armour units....

Mobile units to hydro geochemistry characterization

International Nuclear Information System (INIS)

Gomez, P.; Martinez, B.; Turrero, M.J.

1994-01-01

This report shows the mobile units for hydro geochemical studies. The authors analyze the work of mobile unit and the cars that conform the unit: Sampling car and analysis car: The sampling and equipment are took into account as well

7 CFR 1215.20 - United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1215.20 Section 1215.20 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... United States. United States means all of the States. Popcorn Board ...

UNIT COMMITMENT: A NEW TRUNCATED METHOD OF UNIT ...

African Journals Online (AJOL)

NIJOTECH

Data obtained from the National Electric Power Authority (NEPA) has been used to test the efficacy of this approach. ... every unit in the system must be respected. Some of these ..... Analysis of Power System Reliability. 2.Edwin K. W, Machat, ...

Organization of Control Units with Operational Addressing

OpenAIRE

Alexander A. Barkalov; Roman M. Babakov; Larysa A. Titarenko

2012-01-01

The using of operational addressing unit as the block of control unit is proposed. The new structure model of Moore finite-state machine with reduced hardware amount is developed. The generalized structure of operational addressing unit is suggested. An example of synthesis process for Moore finite-state machine with operational addressing unit is given. The analytical researches of proposed structure of control unit are executed.

Development of a Multisensory Wearable System for Monitoring Cigarette Smoking Behavior in Free-Living Conditions

Directory of Open Access Journals (Sweden)

Masudul Haider Imtiaz

2017-11-01

Full Text Available This paper presents the development and validation of a novel multi-sensory wearable system (Personal Automatic Cigarette Tracker v2 or PACT2.0 for monitoring of cigarette smoking in free-living conditions. The contributions of the PACT2.0 system are: (1 the implementation of a complete sensor suite for monitoring of all major behavioral manifestations of cigarette smoking (lighting events, hand-to-mouth gestures, and smoke inhalations; (2 a miniaturization of the sensor hardware to enable its applicability in naturalistic settings; and (3 an introduction of new sensor modalities that may provide additional insight into smoking behavior e.g., Global Positioning System (GPS, pedometer and Electrocardiogram(ECG or provide an easy-to-use alternative (e.g., bio-impedance respiration sensor to traditional sensors. PACT2.0 consists of three custom-built devices: an instrumented lighter, a hand module, and a chest module. The instrumented lighter is capable of recording the time and duration of all lighting events. The hand module integrates Inertial Measurement Unit (IMU and a Radio Frequency (RF transmitter to track the hand-to-mouth gestures. The module also operates as a pedometer. The chest module monitors the breathing (smoke inhalation patterns (inductive and bio-impedance respiratory sensors, cardiac activity (ECG sensor, chest movement (three-axis accelerometer, hand-to-mouth proximity (RF receiver, and captures the geo-position of the subject (GPS receiver. The accuracy of PACT2.0 sensors was evaluated in bench tests and laboratory experiments. Use of PACT2.0 for data collection in the community was validated in a 24 h study on 40 smokers. Of 943 h of recorded data, 98.6% of the data was found usable for computer analysis. The recorded information included 549 lighting events, 522/504 consumed cigarettes (from lighter data/self-registered data, respectively, 20,158/22,207 hand-to-mouth gestures (from hand IMU/proximity sensor, respectively

Defining and Verifying Research Grade Airborne Laser Swath Mapping (ALSM) Observations

Science.gov (United States)

Carter, W. E.; Shrestha, R. L.; Slatton, C. C.

2004-12-01

The first and primary goal of the National Science Foundation (NSF) supported Center for Airborne Laser Mapping (NCALM), operated jointly by the University of Florida and the University of California, Berkeley, is to make "research grade" ALSM data widely available at affordable cost to the national scientific community. Cost aside, researchers need to know what NCALM considers research grade data and how the quality of the data is verified, to be able to determine the likelihood that the data they receive will meet their project specific requirements. Given the current state of the technology it is reasonable to expect a well planned and executed survey to produce surface elevations with uncertainties less than 10 centimeters and horizontal uncertainties of a few decimeters. Various components of the total error are generally associated with the aircraft trajectory, aircraft orientation, or laser vectors. Aircraft trajectory error is dependent largely on the Global Positioning System (GPS) observations, aircraft orientation on Inertial Measurement Unit (IMU) observations, and laser vectors on the scanning and ranging instrumentation. In addition to the issue of the precision or accuracy of the coordinates of the surface points, consideration must also be given to the point-to-point spacing and voids in the coverage. The major sources of error produce distinct artifacts in the data set. For example, aircraft trajectory errors tend to change slowly as the satellite constellation geometry varies, producing slopes within swaths and offsets between swaths. Roll, pitch and yaw biases in the IMU observations tend to persist through whole flights, and created distinctive artifacts in the swath overlap areas. Errors in the zero-point and scale of the laser scanner cause the edges of swaths to turn up or down. Range walk errors cause offsets between bright and dark surfaces, causing paint stripes to float above the dark surfaces of roads. The three keys to producing

Affordance Realization in Climbing: Learning and Transfer.

Science.gov (United States)

Seifert, Ludovic; Orth, Dominic; Mantel, Bruno; Boulanger, Jérémie; Hérault, Romain; Dicks, Matt

2018-01-01

The aim of this study was to investigate how the affordances of an indoor climbing wall changed for intermediate climbers following a period of practice during which hold orientation was manipulated within a learning and transfer protocol. The learning protocol consisted of four sessions, in which eight climbers randomly ascended three different routes of fixed absolute difficulty (5c on the French scale), as fluently as possible. All three routes were 10.3 m in height and composed of 20 hand-holds at the same locations on an artificial climbing wall; only hold orientations were altered: (i) a horizontal-edge route (H) was designed to afford horizontal hold grasping, (ii) a vertical-edge route (V) afforded vertical hold grasping, and (iii), a double-edge route (D) was designed to afford both horizontal and vertical hold grasping. Five inertial measurement units (IMU) (3D accelerometer, 3D gyroscope, 3D magnetometer) were attached to the hip, feet and forearms to analyze the vertical acceleration and direction (3D unitary vector) of each limb and hip in ambient space during the entire ascent. Segmentation and classification processes supported detection of movement and stationary phases for each IMU. Depending on whether limbs and/or hip were moving, a decision tree distinguished four states of behavior: stationary (absence of limb and hip motion), hold exploration (absence of hip motion but at least one limb in motion), hip movement (hip in motion but absence of limb motion) and global motion (hip in motion and at least one limb in motion). Results showed that with practice, the learners decreased the relative duration of hold exploration, suggesting that they improved affordance perception of hold grasp-ability. The number of performatory movements also decreased as performance increased during learning sessions, confirming that participants' climbing efficacy improved as a function of practice. Last, the results were more marked for the H route, while the D route

Affordance Realization in Climbing: Learning and Transfer

Directory of Open Access Journals (Sweden)

Ludovic Seifert

2018-05-01

Full Text Available The aim of this study was to investigate how the affordances of an indoor climbing wall changed for intermediate climbers following a period of practice during which hold orientation was manipulated within a learning and transfer protocol. The learning protocol consisted of four sessions, in which eight climbers randomly ascended three different routes of fixed absolute difficulty (5c on the French scale, as fluently as possible. All three routes were 10.3 m in height and composed of 20 hand-holds at the same locations on an artificial climbing wall; only hold orientations were altered: (i a horizontal-edge route (H was designed to afford horizontal hold grasping, (ii a vertical-edge route (V afforded vertical hold grasping, and (iii, a double-edge route (D was designed to afford both horizontal and vertical hold grasping. Five inertial measurement units (IMU (3D accelerometer, 3D gyroscope, 3D magnetometer were attached to the hip, feet and forearms to analyze the vertical acceleration and direction (3D unitary vector of each limb and hip in ambient space during the entire ascent. Segmentation and classification processes supported detection of movement and stationary phases for each IMU. Depending on whether limbs and/or hip were moving, a decision tree distinguished four states of behavior: stationary (absence of limb and hip motion, hold exploration (absence of hip motion but at least one limb in motion, hip movement (hip in motion but absence of limb motion and global motion (hip in motion and at least one limb in motion. Results showed that with practice, the learners decreased the relative duration of hold exploration, suggesting that they improved affordance perception of hold grasp-ability. The number of performatory movements also decreased as performance increased during learning sessions, confirming that participants' climbing efficacy improved as a function of practice. Last, the results were more marked for the H route, while the D

7 CFR 1280.127 - United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1280.127 Section 1280.127 Agriculture... INFORMATION ORDER Lamb Promotion, Research, and Information Order Definitions § 1280.127 United States. United States means collectively the 50 States and the District of Columbia. ...

Unit Manning

National Research Council Canada - National Science Library

McGinniss, Mike

2003-01-01

.... This decision combines two crucial initiatives: first, transforming the Army from an individual soldier replacement system to a unit manning system that enhances cohesion and keeps trained soldiers, leaders, and commanders together longer, thereby...

Adaptive Federal Kalman Filtering for SINS/GPS Integrated System

Institute of Scientific and Technical Information of China (English)

杨勇; 缪玲娟

2003-01-01

A new adaptive federal Kalman filter for a strapdown integrated navigation system/global positioning system (SINS/GPS) is given. The developed federal Kalman filter is based on the trace operation of parameters estimation's error covariance matrix and the spectral radius of update measurement noise variance-covariance matrix for the proper choice of the filter weight and hence the filter gain factors. Theoretical analysis and results from simulation in which the SINS/GPS was compared to conventional Kalman filter are presented. Results show that the algorithm of this adaptive federal Kalman filter is simpler than that of the conventional one. Furthermore, it outperforms the conventional Kalman filter when the system is undertaken measurement malfunctions because of its possession of adaptive ability. This filter can be used in the vehicle integrated navigation system.

A Novel System for Correction of Relative Angular Displacement between Airborne Platform and UAV in Target Localization

Directory of Open Access Journals (Sweden)

Chenglong Liu

2017-03-01

Full Text Available This paper provides a system and method for correction of relative angular displacements between an Unmanned Aerial Vehicle (UAV and its onboard strap-down photoelectric platform to improve localization accuracy. Because the angular displacements have an influence on the final accuracy, by attaching a measuring system to the platform, the texture image of platform base bulkhead can be collected in a real-time manner. Through the image registration, the displacement vector of the platform relative to its bulkhead can be calculated to further determine angular displacements. After being decomposed and superposed on the three attitude angles of the UAV, the angular displacements can reduce the coordinate transformation errors and thus improve the localization accuracy. Even a simple kind of method can improve the localization accuracy by 14.3%.

Ecological units: definitions and application.

Science.gov (United States)

Jax, Kurt

2006-09-01

Concepts of ecological units, such as population, community, and ecosystem, are at the basis of ecological theory and research and have increasingly become the focus of conservation strategies. Concepts of these units still suffer from inconsistencies and confusions over terminology. The different concepts are treated here together as a common "conceptual cluster," with similar ecological functions (roles) and similar problems in their definition and use. An analysis of the multitude of existing terms and concepts that have been developed for these units reveals that they differ with respect to at least four basic criteria: (i) the questions as to whether they are defined statistically or via a network of interactions; (ii) if their boundaries are drawn by topographical or process-related criteria; (iii) how high the required internal relationships are; and (iv) if they are perceived as "real" entities or abstractions by an observer The various definitions cannot be easily sorted into just a few types, but they can be characterized by several independent criteria. I argue that serious problems arise if the different possibilities of defining ecological units are not recognized and if the concepts are perceived as self-evident. The different concepts of ecological units should be defined and used in a philosophically informed manner I propose a dual approach to the use of ecological units. Generic meanings of the main concepts (especially population, community, and ecosystem) should be retained only as heuristically useful perspectives, while specific and "operational" definitions of the concepts as units should be developed, depending on specific purposes of their use. Some thoughts on the basic requirements for such definitions and the domains of their uses are briefly explained.

7 CFR 1260.108 - United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1260.108 Section 1260.108 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Promotion and Research Order Definitions § 1260.108 United States. United States means the 50 States and the...

7 CFR 1221.32 - United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1221.32 Section 1221.32 Agriculture... INFORMATION ORDER Sorghum Promotion, Research, and Information Order Definitions § 1221.32 United States. United States or U.S. means collectively the 50 States, the District of Columbia, the Commonwealth of...

7 CFR 1216.30 - United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1216.30 Section 1216.30 Agriculture... INFORMATION ORDER Peanut Promotion, Research, and Information Order Definitions § 1216.30 United States. United States means collectively the 50 states, the District of Columbia, the Commonwealth of Puerto Rico...

7 CFR 1218.22 - United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1218.22 Section 1218.22 Agriculture... INFORMATION ORDER Blueberry Promotion, Research, and Information Order Definitions § 1218.22 United States. United States means collectively the 50 states, the District of Columbia, the Commonwealth of Puerto Rico...

Accurate 3D Positioning for a Mobile Platform in Non-Line-of-Sight Scenarios Based on IMU/Magnetometer Sensor Fusion.

Science.gov (United States)

Hellmers, Hendrik; Kasmi, Zakaria; Norrdine, Abdelmoumen; Eichhorn, Andreas

2018-01-04

In recent years, a variety of real-time applications benefit from services provided by localization systems due to the advent of sensing and communication technologies. Since the Global Navigation Satellite System (GNSS) enables localization only outside buildings, applications for indoor positioning and navigation use alternative technologies. Ultra Wide Band Signals (UWB), Wireless Local Area Network (WLAN), ultrasonic or infrared are common examples. However, these technologies suffer from fading and multipath effects caused by objects and materials in the building. In contrast, magnetic fields are able to pass through obstacles without significant propagation errors, i.e. in Non-Line of Sight Scenarios (NLoS). The aim of this work is to propose a novel indoor positioning system based on artificially generated magnetic fields in combination with Inertial Measurement Units (IMUs). In order to reach a better coverage, multiple coils are used as reference points. A basic algorithm for three-dimensional applications is demonstrated as well as evaluated in this article. The established system is then realized by a sensor fusion principle as well as a kinematic motion model on the basis of a Kalman filter. Furthermore, a pressure sensor is used in combination with an adaptive filtering method to reliably estimate the platform's altitude.

A pedestrian dead-reckoning system that considers the heel-strike and toe-off phases when using a foot-mounted IMU

Science.gov (United States)

Ju, Hojin; Lee, Min Su; Park, So Young; Song, Jin Woo; Park, Chan Gook

2016-01-01

In this paper, we propose an advanced pedestrian dead-reckoning (PDR) algorithm that considers the heel-strike and toe-off phases. Generally, PDR systems that use a foot-mounted inertial measurement unit are based on an inertial navigation system with an extended Kalman filter (EKF). To reduce the influence of the bias and white noises in the gyroscope and accelerometer signals, a zero-velocity update is often adopted at the stance phase. However, transient and large acceleration, which cannot be measured by the accelerometer used in pedestrian navigation, occur momentarily in the heel-strike phase. The velocity information from integration of the acceleration is not reliable because the acceleration is not measured in the heel-strike phase. Therefore, the designed EKF does not correctly reflect the actual environment, because conventional algorithms do not take the non-measurable acceleration into consideration. In order to reflect the actual environment, we propose a PDR system that considers the non-measurable acceleration from the heel-strike impact. To improve the PDR system’s performance, the proposed algorithm uses a new velocity measurement obtained using the constraint between the surface and the foot during the toe-off phase. The experimental results show improved filter performance after comparison of the proposed algorithm and a conventional algorithm.

A pedestrian dead-reckoning system that considers the heel-strike and toe-off phases when using a foot-mounted IMU

International Nuclear Information System (INIS)

Ju, Hojin; Lee, Min Su; Park, So Young; Park, Chan Gook; Song, Jin Woo

2016-01-01

In this paper, we propose an advanced pedestrian dead-reckoning (PDR) algorithm that considers the heel-strike and toe-off phases. Generally, PDR systems that use a foot-mounted inertial measurement unit are based on an inertial navigation system with an extended Kalman filter (EKF). To reduce the influence of the bias and white noises in the gyroscope and accelerometer signals, a zero-velocity update is often adopted at the stance phase. However, transient and large acceleration, which cannot be measured by the accelerometer used in pedestrian navigation, occur momentarily in the heel-strike phase. The velocity information from integration of the acceleration is not reliable because the acceleration is not measured in the heel-strike phase. Therefore, the designed EKF does not correctly reflect the actual environment, because conventional algorithms do not take the non-measurable acceleration into consideration. In order to reflect the actual environment, we propose a PDR system that considers the non-measurable acceleration from the heel-strike impact. To improve the PDR system’s performance, the proposed algorithm uses a new velocity measurement obtained using the constraint between the surface and the foot during the toe-off phase. The experimental results show improved filter performance after comparison of the proposed algorithm and a conventional algorithm. (paper)

[Aftercare for durability and profitability of single-unit and multi-unit fixed dental prostheses

NARCIS (Netherlands)

Baat, C. de; Loveren, C. van; Maarel-Wierink, C.D. van der; Witter, D.J.; Creugers, N.H.J.

2013-01-01

An important aim ofa treatment with single-unit and multi-unit fixed dental prostheses is a durable and profitable treatment outcome. That requires aftercare, too. First, the frequency of routine oral examinations should be assessed, using an individual risk profile. The objectives of the routine

24 CFR 970.31 - Replacement units.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Replacement units. 970.31 Section... PUBLIC HOUSING PROGRAM-DEMOLITION OR DISPOSITION OF PUBLIC HOUSING PROJECTS § 970.31 Replacement units. Notwithstanding any other provision of law, replacement public housing units may be built on the original public...

Image processing unit with fall-back.

NARCIS (Netherlands)

2011-01-01

An image processing unit ( 100,200,300 ) for computing a sequence of output images on basis of a sequence of input images, comprises: a motion estimation unit ( 102 ) for computing a motion vector field on basis of the input images; a quality measurement unit ( 104 ) for computing a value of a

7 CFR 1210.315 - United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false United States. 1210.315 Section 1210.315 Agriculture... PLAN Watermelon Research and Promotion Plan Definitions § 1210.315 United States. United States means each of the several States and the District of Columbia. [60 FR 10797, Feb. 28, 1995] National...

Radix-16 Combined Division and Square Root Unit

DEFF Research Database (Denmark)

Nannarelli, Alberto

2011-01-01

Division and square root, based on the digitrecurrence algorithm, can be implemented in a combined unit. Several implementations of combined division/square root units have been presented mostly for radices 2 and 4. Here, we present a combined radix-16 unit obtained by overlapping two radix-4...... result digit selection functions, as it is normally done for division only units. The latency of the unit is reduced by retiming and low power methods are applied as well. The proposed unit is compared to a radix-4 combined division/square root unit, and to a radix-16 unit, obtained by cascading two...

Ad valorem versus unit taxes

DEFF Research Database (Denmark)

Schröder, Philipp J.H.; Sørensen, Allan

2010-01-01

a general equilibrium monopolistic competition model with heterogeneous firms and intra-industry reallocations. We show that the welfare superiority of ad valorem over unit taxes under imperfect competition is not only preserved but amplified. The additional difference between the tools arises because unit...... taxes distort relative prices, which in turn reduces average industry productivity through reallocations (the survival and increased market share of lower productivity firms). Importantly, numerical solutions of the model reveal that the relative welfare loss from using the unit tax increases...

Discovering the impact of preceding units' characteristics on the wait time of cardiac surgery unit from statistic data.

Directory of Open Access Journals (Sweden)

Jiming Liu

Full Text Available INTRODUCTION: Prior research shows that clinical demand and supplier capacity significantly affect the throughput and the wait time within an isolated unit. However, it is doubtful whether characteristics (i.e., demand, capacity, throughput, and wait time of one unit would affect the wait time of subsequent units on the patient flow process. Focusing on cardiac care, this paper aims to examine the impact of characteristics of the catheterization unit (CU on the wait time of cardiac surgery unit (SU. METHODS: This study integrates published data from several sources on characteristics of the CU and SU units in 11 hospitals in Ontario, Canada between 2005 and 2008. It proposes a two-layer wait time model (with each layer representing one unit to examine the impact of CU's characteristics on the wait time of SU and test the hypotheses using the Partial Least Squares-based Structural Equation Modeling analysis tool. RESULTS: Results show that: (i wait time of CU has a direct positive impact on wait time of SU (β = 0.330, p < 0.01; (ii capacity of CU has a direct positive impact on demand of SU (β = 0.644, p < 0.01; (iii within each unit, there exist significant relationships among different characteristics (except for the effect of throughput on wait time in SU. CONCLUSION: Characteristics of CU have direct and indirect impacts on wait time of SU. Specifically, demand and wait time of preceding unit are good predictors for wait time of subsequent units. This suggests that considering such cross-unit effects is necessary when alleviating wait time in a health care system. Further, different patient risk profiles may affect wait time in different ways (e.g., positive or negative effects within SU. This implies that the wait time management should carefully consider the relationship between priority triage and risk stratification, especially for cardiac surgery.

Advancements of In-Flight Mass Moment of Inertia and Structural Deflection Algorithms for Satellite Attitude Simulators

Science.gov (United States)

2015-03-26

is suggested that an Arduino ® board be used to interpret the 0-5 V desired position input and control the actuator by providing an extend and contract...command signal while using the actuators’ position potentiometer output to close the control loop. The Arduino ® board can calculate the control...IMU drift and would allow for more repeatable experiments. Additionally, we recommend adding an Arduino ® board attached to two current sensors, two

12 CFR 541.10 - Dwelling unit.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Dwelling unit. 541.10 Section 541.10 Banks and... FEDERAL SAVINGS ASSOCIATIONS § 541.10 Dwelling unit. The term dwelling unit means the unified combination of rooms designed for residential use by one family, other than a single-family dwelling. ...

Stroke Unit: General principles and standards

Directory of Open Access Journals (Sweden)

Mehmet Akif Topçuoğlu

2015-04-01

Full Text Available Evidence-based medicinal methods have convincingly shown that stroke unit approach reduces mortality and disability rates, improves the quality of life and economic burden resulting from acute ischemic and hemorrhagic stroke. Any contemporary stroke system of care cannot be successful without putting the stroke unit concept in the center of its organization. Stroke units are the main elements of primary and comprehensive stroke centers. As a modernization process, this article focuses on practical issues and suggestions related to integration of the stroke unit approach to a regionally organized stroke system of care for perusal by not only national health authorities and service providers, but also neurologists. Stroke unit quality metrics revisited herein are of critical importance for hospitals establishing or renovating primary and comprehensive stroke centers.

SPOKEN CUZCO QUECHUA, UNITS 1-6.

Science.gov (United States)

SOLA, DONALD F.; AND OTHERS

THE MATERIALS IN THIS VOLUME COMPRISE SIX UNITS WHICH PRESENT BASIC ASPECTS OF CUZCO QUECHUA PHONOLOGY, MORPHOLOGY, AND SYNTAX FOR THE BEGINNING STUDENT. THE SIX UNITS ARE DESIGNED FOR APPROXIMATELY 120 HOURS OF SUPERVISED CLASS WORK WITH OUTSIDE PREPARATION EXPECTED OF THE STUDENT. EACH UNIT CONSISTS OF A DIALOGUE TO BE MEMORIZED, A DIALOGUE…

United Kingdom and United States Tourism Demand for Malaysia:A Cointegration Analysis

OpenAIRE

Habibi, Fateh; Abdul Rahim, Khalid; Chin, Lee

2008-01-01

Tourism industry has been an important contributor to the Malaysia economy. In this paper we inspect variations in the long run demand for tourism from United Kingdom and United States to Malaysia. The demand for tourism has been explained by macroeconomic variables, including income in origin countries, tourism prices in Malaysia, and travel cost between the two countries. Annual data from 1972 to 2006 are used for the analysis. Augmented Dickey-Fuller and Johansen’s maximum likelihood tests...

PENGEMBANGAN STRATEGIC BUSINESS UNIT PERHUTANI UNIT III JAWA BARAT DAN BANTEN

Directory of Open Access Journals (Sweden)

Rurin Wahyu Listriana

2014-09-01

Full Text Available ABSTRACTThis study aimed to 1 analyze the innovation and competitiveness ability of Strategic Business Unit (SBU in the KBM (independent business unit industri and 2 formulate alternative policies that can enhance company innovation and competitiveness. The study was conducted at KBM Industri and SBU within the KBM industri. The information and data was obtained through interviews and distributing questionnaires to 10 respondents. Respondents were chosen based on their expertise and or experience. Data processing techniques used the SWOT analysis and Analytic Hierarchy Process (AHP. Results of this study shows that KBM Industri Unit III have the power and the opportunity to expand, increase growth, and achieve maximum progress by improving the quality, developing new products, improving processes and increasing access to wider market. The potential innovation can also be seen from the process-product innovation, knowledge-skills innovation and method-system innovation. In the KBM Industri Unit III, those potential covers the raw materials, process equipment and products. The improvement of company's innovation was influenced by the main factor organization with the value 0,436 and the most influential factors of marketing with a value 0,398, while the ultimate goal is the improvement of the process with the value 0,756. The improvement of the company's innovation strategy is through strategy priority, namely cooperation with other /external parties weighted by 0,703 and optimizing own capabilities of the research or conducting institutions development research weighted by 0,297.Keywords: SBU, KBM Industri, Innovation, AHP, SWOTABSTRAKPenelitian ini bertujuan 1 menganalisis kemampuan inovasi dan daya saing Strategic Business Unit (SBU di Kesatuan Bisnis Mandiri (KBM Industri dan 2 merumuskan kebijakan alternatif yang dapat meningkatkan inovasi dan daya saing perusahaan. Penelitian  dilakukan pada KBM Industri  dan SBU yang ada didalam  KBM

Development of diagnostic mammography unit

Energy Technology Data Exchange (ETDEWEB)

Matsubara, M.; Muraki, T.; Kitade, K. (Toshiba Corp., Kawasaki, Kanagawa (Japan))

1981-07-01

The mortality from breast cancer is gradually increasing year after year. Accordingly, it is eagerly desired that X-ray diagnosis information be obtainable with higher accuracy and ease for early detection of the disease. Meeting this demand, development has been made of a 2 x magnification mammography unit (Model MGU-01) capabel of minutely depicting microcalcifications with a size of 150 ..mu..m or thereabout and the peripheral condition of a mammary abscess. The background of the development, the substance of the unit and the examination made of the unit are described here.

Development of diagnostic mammography unit

International Nuclear Information System (INIS)

Matsubara, Mitsuyoshi; Muraki, Takeshi; Kitade, Kooichi

1981-01-01

The mortality from breast cancer is gradually increasing year after year. Accordingly, it is eagerly desired that X-ray diagnosis information be obtainable with higher accuracy and ease for early detection of the disease. Meeting this demand, development has been made of a 2 x magnification mammography unit (Model MGU-01) capabel of minutely depicting microcalcifications with a size of 150 μm or thereabout and the peripheral condition of a mammary abscess. The background of the development, the substance of the unit and the examination made of the unit are described here. (author)

Design of Dolos Armour Units

DEFF Research Database (Denmark)

Burcharth, H. F.; Liu, Zhou

1993-01-01

The slender, complex types of armour units, such as Tetrapods and Dolosse are widely used. Many of the recent failures are such rubble mound breakwaters revealed that there is an imbalance between strength (structural integrity) of the units and the hydraulic stability (resistance to displacements......) of the armour layers. The paper deals only with dolos armour and presents the first design diagrammes and formulae where stresses from static, quasistatic and impact loads are implemented as well as the hydraulic stability. The dolos is treated as a multi shape unit where the thickness can be adjusted...

Oil Vulnerabilities and United States Strategy

Science.gov (United States)

2007-02-08

Mazda, Mercedes - Benz , Ford, Mercury, and Nissan offer flexible fuel vehicles in the United States. Ethanol is currently produced in the United States...USAWC STRATEGY RESEARCH PROJECT OIL VULNERABILITIES AND UNITED STATES STRATEGY by Colonel Shawn P. Walsh...Colleges and Schools, 3624 Market Street, Philadelphia, PA 19104, (215) 662-5606. The Commission on Higher Education is an institutional accrediting

Vehicle with inclinable caterpillar propulsion units

International Nuclear Information System (INIS)

Clar, G.

1991-01-01

This vehicle usable in hostile environment such nuclear industry has four propulsion units with a caterpillar track and two integrated motors: one for advancing the caterpillar track and the other for inclining the propulsion unit when overcoming obstacles. Each propulsion unit is easily replaceable because there are no mechanical parts in the body of the vehicle [fr

Discovering the impact of preceding units' characteristics on the wait time of cardiac surgery unit from statistic data.

Science.gov (United States)

Liu, Jiming; Tao, Li; Xiao, Bo

2011-01-01

Prior research shows that clinical demand and supplier capacity significantly affect the throughput and the wait time within an isolated unit. However, it is doubtful whether characteristics (i.e., demand, capacity, throughput, and wait time) of one unit would affect the wait time of subsequent units on the patient flow process. Focusing on cardiac care, this paper aims to examine the impact of characteristics of the catheterization unit (CU) on the wait time of cardiac surgery unit (SU). This study integrates published data from several sources on characteristics of the CU and SU units in 11 hospitals in Ontario, Canada between 2005 and 2008. It proposes a two-layer wait time model (with each layer representing one unit) to examine the impact of CU's characteristics on the wait time of SU and test the hypotheses using the Partial Least Squares-based Structural Equation Modeling analysis tool. Results show that: (i) wait time of CU has a direct positive impact on wait time of SU (β = 0.330, p relationships among different characteristics (except for the effect of throughput on wait time in SU). Characteristics of CU have direct and indirect impacts on wait time of SU. Specifically, demand and wait time of preceding unit are good predictors for wait time of subsequent units. This suggests that considering such cross-unit effects is necessary when alleviating wait time in a health care system. Further, different patient risk profiles may affect wait time in different ways (e.g., positive or negative effects) within SU. This implies that the wait time management should carefully consider the relationship between priority triage and risk stratification, especially for cardiac surgery.

31 CFR 596.313 - United States person.

Science.gov (United States)

2010-07-01

... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY TERRORISM LIST GOVERNMENTS SANCTIONS REGULATIONS General Definitions § 596.313 United States person. The term United States person means any United States...

Critical Concerns for Oral Communication Education in the United States and the United Kingdom

Science.gov (United States)

Emanuel, Richard

2011-01-01

An examination of oral communication education in the United States (U.S.) and United Kingdom (U.K.) identified four critical concerns: (1) Today's college students are not getting adequate oral communication education; (2) Oral communication education is being relegated to a "module" in another discipline-specific course; (3) When an…

Edexcel A2 Physics Student Unit Guide

CERN Document Server

Benn, Mike

2010-01-01

Student Unit Guides are perfect for revision. Each guide is written by an examiner and explains the unit requirements, summarises the relevant unit content and includes a series of specimen questions and answers. There are three sections to each guide:. Introduction - includes advice on how to use the guide, an explanation of the skills being tested by the assessment objectives, an outline of the unit or module and, depending on the unit, suggestions for how to revise effectively and prepare for the examination questions. Content Guidance - provides an examiner's overview of the module's key t

AQA A2 Chemistry Student Unit Guide

CERN Document Server

Cross, Margaret

2010-01-01

Student Unit Guides are perfect for revision. Each guide is written by an examiner and explains the unit requirements, summarises the relevant unit content and includes a series of specimen questions and answers. There are three sections to each guide:. Introduction - includes advice on how to use the guide, an explanation of the skills being tested by the assessment objectives, an outline of the unit or module and, depending on the unit, suggestions for how to revise effectively and prepare for the examination questions. Content Guidance - provides an examiner's overview of the module's key t

Nuclear development in the United States

International Nuclear Information System (INIS)

Brewer, S.

1983-01-01

The history of the nuclear development in the United States has been one of international cooperation relations so far. The United States is to offer the technical information on atomic energy utilization to foreign countries in exchange for the guarantee that they never attempt to have or develop nuclear weapons. Actually, the United States has supplied the technologies on nuclear fuel cycle and other related fields to enable other countries to achieve economical and social progress. The Department of Energy clarified the public promise of the United States regarding the idea of international energy community. The ratio of nuclear power generation to total electric power supply in the United States exceeded 12%, and will exceed 20% by 1990. Since 1978, new nuclear power station has not been ordered, and some of the contracted power stations were canceled. The atomic energy industry in the United States prospered at the beginning of 1970s, but lost the spirit now, mainly due to the institutional problems rather than the technical ones. As the policy of the government to eliminate the obstacles, the improvement of the procedure for the permission and approval, the establishment of waste disposal capability, the verification of fast breeder reactor technology and the promotion of commercial fuel reprocessing were proposed. The re-establishment of the United States as the reliable supplier of atomic energy service is the final aim. (Kako, I.)

Fatigue of Concrete Armour Units

DEFF Research Database (Denmark)

Sørensen, N. B.; Burcharth, H. F.; Liu, Z.

1995-01-01

In the present article fatigue as a possible reason for failure of Dolosse armour units made of plain concrete is discussed.......In the present article fatigue as a possible reason for failure of Dolosse armour units made of plain concrete is discussed....

Dedicated education unit: student perspectives.

Science.gov (United States)

Nishioka, Vicki M; Coe, Michael T; Hanita, Makoto; Moscato, Susan R

2014-01-01

The study compared students' perceptions of their clinical learning experiences in a dedicated education unit (DEU) with their experiences in traditional clinical education. Unlike traditional academic-instructor models, expert nurses in the DEU provide clinical education to students with faculty support. This repeated measures design used student surveys, supplemented by focus group data. Students were more likely to agree that their clinical learning experience was high quality and they had a consistent mentoring relationship during DEU rotations. Students also reported the quality of the unit's learning environment, the leadership style of the nurse manager, and the nursing care on the unit was more favorable in DEUs than traditional units. Consistent with their changed role in DEUs, faculty members were less active in helping students integrate theory and practice. These findings provide additional evidence of the value that the DEU model contributes to high-quality clinical education.

Designing and Testing a UAV Mapping System for Agricultural Field Surveying

Directory of Open Access Journals (Sweden)

Martin Peter Christiansen

2017-11-01

Full Text Available A Light Detection and Ranging (LiDAR sensor mounted on an Unmanned Aerial Vehicle (UAV can map the overflown environment in point clouds. Mapped canopy heights allow for the estimation of crop biomass in agriculture. The work presented in this paper contributes to sensory UAV setup design for mapping and textual analysis of agricultural fields. LiDAR data are combined with data from Global Navigation Satellite System (GNSS and Inertial Measurement Unit (IMU sensors to conduct environment mapping for point clouds. The proposed method facilitates LiDAR recordings in an experimental winter wheat field. Crop height estimates ranging from 0.35–0.58 m are correlated to the applied nitrogen treatments of 0–300 kg N ha . The LiDAR point clouds are recorded, mapped, and analysed using the functionalities of the Robot Operating System (ROS and the Point Cloud Library (PCL. Crop volume estimation is based on a voxel grid with a spatial resolution of 0.04 × 0.04 × 0.001 m. Two different flight patterns are evaluated at an altitude of 6 m to determine the impacts of the mapped LiDAR measurements on crop volume estimations.

3D indoor modeling using a hand-held embedded system with multiple laser range scanners

Science.gov (United States)

Hu, Shaoxing; Wang, Duhu; Xu, Shike

2016-10-01

Accurate three-dimensional perception is a key technology for many engineering applications, including mobile mapping, obstacle detection and virtual reality. In this article, we present a hand-held embedded system designed for constructing 3D representation of structured indoor environments. Different from traditional vehicle-borne mobile mapping methods, the system presented here is capable of efficiently acquiring 3D data while an operator carrying the device traverses through the site. It consists of a simultaneous localization and mapping(SLAM) module, a 3D attitude estimate module and a point cloud processing module. The SLAM is based on a scan matching approach using a modern LIDAR system, and the 3D attitude estimate is generated by a navigation filter using inertial sensors. The hardware comprises three 2D time-flight laser range finders and an inertial measurement unit(IMU). All the sensors are rigidly mounted on a body frame. The algorithms are developed on the frame of robot operating system(ROS). The 3D model is constructed using the point cloud library(PCL). Multiple datasets have shown robust performance of the presented system in indoor scenarios.

Autonomous mobile robot localization using Kalman filter

Directory of Open Access Journals (Sweden)

Mohd Nasir Nabil Zhafri

2017-01-01

Full Text Available Autonomous mobile robot field has gain interest among researchers in recent years. The ability of a mobile robot to locate its current position and surrounding environment is the fundamental in order for it to operate autonomously, which commonly known as localization. Localization of mobile robot are commonly affected by the inaccuracy of the sensors. These inaccuracies are caused by various factors which includes internal interferences of the sensor and external environment noises. In order to overcome these noises, a filtering method is required in order to improve the mobile robot’s localization. In this research, a 2- wheeled-drive (2WD mobile robot will be used as platform. The odometers, inertial measurement unit (IMU, and ultrasonic sensors are used for data collection. Data collected is processed using Kalman filter to predict and correct the error from these sensors reading. The differential drive model and measurement model which estimates the environmental noises and predict a correction are used in this research. Based on the simulation and experimental results, the x, y and heading was corrected by converging the error to10 mm, 10 mm and 0.06 rad respectively.

Gesture-Based Robot Control with Variable Autonomy from the JPL Biosleeve

Science.gov (United States)

Wolf, Michael T.; Assad, Christopher; Vernacchia, Matthew T.; Fromm, Joshua; Jethani, Henna L.

2013-01-01

This paper presents a new gesture-based human interface for natural robot control. Detailed activity of the user's hand and arm is acquired via a novel device, called the BioSleeve, which packages dry-contact surface electromyography (EMG) and an inertial measurement unit (IMU) into a sleeve worn on the forearm. The BioSleeve's accompanying algorithms can reliably decode as many as sixteen discrete hand gestures and estimate the continuous orientation of the forearm. These gestures and positions are mapped to robot commands that, to varying degrees, integrate with the robot's perception of its environment and its ability to complete tasks autonomously. This flexible approach enables, for example, supervisory point-to-goal commands, virtual joystick for guarded teleoperation, and high degree of freedom mimicked manipulation, all from a single device. The BioSleeve is meant for portable field use; unlike other gesture recognition systems, use of the BioSleeve for robot control is invariant to lighting conditions, occlusions, and the human-robot spatial relationship and does not encumber the user's hands. The BioSleeve control approach has been implemented on three robot types, and we present proof-of-principle demonstrations with mobile ground robots, manipulation robots, and prosthetic hands.