Application of a Full Body Inertial Measurement System in Alpine Skiing: A Comparison with an Optical Video Based System

2010 ◽  
Vol 26 (4) ◽  
pp. 516-521 ◽  
Author(s):  
Andreas Krüger ◽  
Jürgen Edelmann-Nusser
Keyword(s):  
Measurement System ◽  
Small Time ◽  
Optical Methods ◽  
Alpine Skiing ◽  
Inertial Measurement ◽  
Measurement Systems ◽  
Quantitative Validation ◽  
Kinematical Parameters ◽  
Full Body

This study aims at determining the accuracy of a full body inertial measurement system in a real skiing environment in comparison with an optical video based system. Recent studies have shown the use of inertial measurement systems for the determination of kinematical parameters in alpine skiing. However, a quantitative validation of a full body inertial measurement system for the application in alpine skiing is so far not available. For the purpose of this study, a skier performed a test-run equipped with a full body inertial measurement system in combination with a DGPS. In addition, one turn of the test-run was analyzed by an optical video based system. With respect to the analyzed angles, a maximum mean difference of 4.9° was measured. No differences in the measured angles between the inertial measurement system and the combined usage with a DGPS were found. Concerning the determination of the skier’s trajectory, an additional system (e.g., DGPS) must be used. As opposed to optical methods, the main advantages of the inertial measurement system are the determination of kinematical parameters without the limitation of restricted capture volume, and small time costs for the measurement preparation and data analysis.

scholarly journals Conversion of Video Surveillance System into Measurement System based on Video Camera

2019 ◽  
Vol 8 (12) ◽  
pp. 400-404
Keyword(s):  
Video Surveillance ◽  
Measurement System ◽  
Surveillance System ◽  
Measurement Errors ◽  
Video Camera ◽  
Video Surveillance System ◽  
Video Cameras ◽  
Measurement Systems ◽  
Advantages And Disadvantages

This work reviews measurement systems applied for static and dynamic detection of object coordinates as well as acquiring information of their position at various distances. The market of measurement systems based on video cameras has been analyzed. Their classification is presented, fields of application are described, advantages and disadvantages are summarized for each type of measurement systems. In addition, it has been revealed that the frequency and extent of measurement errors depend not only on the quality on system components but also on numerous other factors, such as light flare, microvibrations, thermal expansion, etc. The review of measurement systems is necessary for determination of the most efficient method of conversion of video surveillance system into measurement system.

scholarly journals A Novel Camera-Based Measurement System for Roughness Determination of Concrete Surfaces

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 158
Author(s):  
Barış Özcan ◽  
Raimund Schwermann ◽  
Jörg Blankenbach
Keyword(s):  
3D Reconstruction ◽  
Measurement System ◽  
State Of The Art ◽  
Concrete Structures ◽  
Point Clouds ◽  
Measurement Systems ◽  
Strong Linear Correlation ◽  
Building Component ◽  
Sand Patch

Determining the roughness of technical surfaces is an important task in many engineering disciplines. In civil engineering, for instance, the repair and reinforcement of building component parts (such as concrete structures) requires a certain surface roughness in order to ensure the bond between a coating material and base concrete. The sand patch method is so far the state-of-the-art for the roughness measurement of concrete structures. Although the method is easy to perform, it suffers from considerable drawbacks. Consequently, more sophisticated measurement systems are required. In a research project, we developed a novel camera-based alternative, which comes with several advantages. The measurement system consists of a mechanical cross slide that guides an industrial camera over a surface to be measured. Images taken by the camera are used for 3D reconstruction. Finally, the reconstructed point clouds are used to estimate roughness. In this article, we present our measurement system (including the hardware and the self-developed software for 3D reconstruction). We further provide experiments to camera calibration and evaluation of our system on concrete specimens. The resulting roughness estimates for the concrete specimens show a strong linear correlation to reference values obtained by the sand patch method.

Application of a Full Body Inertial Measurement System in Dressage Riding

2014 ◽  
Vol 34 (11-12) ◽  
pp. 1294-1299 ◽  
Author(s):  
Falko Eckardt ◽  
Andreas Münz ◽  
Kerstin Witte
Keyword(s):  
Measurement System ◽  
Inertial Measurement ◽  
Full Body

Determination of cores electrification during the flow in the modified Wurster apparatus

2016 ◽  
Vol 1 (20) ◽  
pp. 5-15
Author(s):  
Wojciech Ludwig ◽  
Tadeusz Mączka
Keyword(s):  
Measurement System ◽  
Charge Accumulation ◽  
Laboratory Conditions ◽  
Pharmaceutical Materials

The purpose of this paper was presentation of the value of cores electrification during their flow in the modified Wurster apparatus, applied for dry encapsulation of pharmaceutical materials. Previous works of the authors dealt with vulnerability of the particles of different diameter, produced by SYNTAPHARM (Cellets 1000, 700 and 100) on electrification in laboratory conditions. The presented work gives the results of examination on particles electrification in real conditions of their stable circulation in a column. The measurement system, that was applied, allowed determination of electrification potential and electrification current. Those quantities, which are the measures of charge accumulation on cores were determined for several particles (Cellets 1000, 700 and 500) with the different humidity, for different mass of the bed and spouting gas velocities.

Concurrent validity of an inertial measurement system in tennis forehand drive

2021 ◽  
Vol 121 ◽  
pp. 110410
Author(s):  
Bruno Pedro ◽  
Sílvia Cabral ◽  
António Prieto Veloso
Keyword(s):  
Measurement System ◽  
Concurrent Validity ◽  
Inertial Measurement

scholarly journals Development of Thermal Performance Metrics for Direct Gas-Fired Circulating Heaters

Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 588
Author(s):  
Benjamin C. Smith ◽  
Brett C. Ramirez ◽  
Steven J. Hoff
Keyword(s):  
Mass Flow ◽  
Measurement System ◽  
Thermal Efficiency ◽  
Performance Metrics ◽  
Standardized Test ◽  
Flow System ◽  
Standard Test ◽  
Testing System ◽  
Measurement Systems ◽  
Selection Of

Many climate-controlled agricultural buildings use direct gas-fired circulating heaters (DGFCH) for supplement heat. There is no standardized test to calculate thermal efficiency for these heaters. This study aimed to develop a measurement system and analytical analysis for thermal efficiency, quantify the measurement uncertainty, and assess economics of DGFCH efficiency. The measurement system developed was similar to the ASHRAE 103 standard test stand with adaptations to connect the apparatus to the DGFCH. Two different propane measurement systems were used: input ratings < 30 kW used a mass flow system and input ratings > 30 kW used a volumetric gas meter. Three DGFCHs (21.9, 29.3, 73.3 kW) were tested to evaluate the system. Thermal efficiencies ranged from 92.4% to 100.9%. The resulting uncertainty (coverage factor of 2; ~95% Confidence Interval) ranged from 13.1% to 30.7% for input ratings of 56.3 to 11.4 kW. Key sources of uncertainty were propane and mass flow of air measurement. The economic impact of 1% difference in thermal efficiency ranged from USD $61.3 to $72.0 per heating season. Refinement of the testing system and procedures are needed to reduce the uncertainty. The application of this system will aid building designers in selection of DGFCHs for various applications.

scholarly journals Measuring Gait Velocity and Stride Length with an Ultrawide Bandwidth Local Positioning System and an Inertial Measurement Unit

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 2896
Author(s):  
Pratham Singh ◽  
Michael Esposito ◽  
Zach Barrons ◽  
Christian A. Clermont ◽  
John Wannop ◽  
...  
Keyword(s):  
Gold Standard ◽  
Gait Speed ◽  
Inertial Measurement Unit ◽  
Stride Length ◽  
Measurement Unit ◽  
Gait Velocity ◽  
Positioning System ◽  
Inertial Measurement ◽  
Measurement Systems ◽  
Local Positioning System

One possible modality to profile gait speed and stride length includes using wearable technologies. Wearable technology using global positioning system (GPS) receivers may not be a feasible means to measure gait speed. An alternative may include a local positioning system (LPS). Considering that LPS wearables are not good at determining gait events such as heel strikes, applying sensor fusion with an inertial measurement unit (IMU) may be beneficial. Speed and stride length determined from an ultrawide bandwidth LPS equipped with an IMU were compared to video motion capture (i.e., the “gold standard”) as the criterion standard. Ninety participants performed trials at three self-selected walk, run and sprint speeds. After processing location, speed and acceleration data from the measurement systems, speed between the last five meters and stride length in the last stride of the trial were analyzed. Small biases and strong positive intraclass correlations (0.9–1.0) between the LPS and “the gold standard” were found. The significance of the study is that the LPS can be a valid method to determine speed and stride length. Variability of speed and stride length can be reduced when exploring data processing methods that can better extract speed and stride length measurements.

scholarly journals Development and Validation of Optical Methods for Zeta Potential Determination of Silica and Polystyrene Particles in Aqueous Suspensions

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 290
Author(s):  
Yannic Ramaye ◽  
Marta Dabrio ◽  
Gert Roebben ◽  
Vikram Kestens
Keyword(s):  
Zeta Potential ◽  
Particle Tracking ◽  
Colloidal Stability ◽  
Optical Methods ◽  
Intermediate Precision ◽  
Electrophoretic Light Scattering ◽  
Measurement Uncertainties ◽  
Development And Validation ◽  
Direct Implementation

Zeta potential is frequently used to examine the colloidal stability of particles and macromolecules in liquids. Recently, it has been suggested that zeta potential can also play an important role for grouping and read-across of nanoforms in a regulatory context. Although the measurement of zeta potential is well established, only little information is reported on key metrological principles such as validation and measurement uncertainties. This contribution presents the results of an in-house validation of the commonly used electrophoretic light scattering (ELS) and the relatively new particle tracking analysis (PTA) methods. The performance characteristics were assessed by analyzing silica and polystyrene reference materials. The ELS and PTA methods are robust and have particle mass working ranges of 0.003 mg/kg to 30 g/kg and 0.03 mg/kg to 1.5 mg/kg, respectively. Despite different measurement principles, both methods exhibit similar uncertainties for repeatability (2%), intermediate precision (3%) and trueness (4%). These results confirm that the developed methods can accurately measure the zeta potential of silica and polystyrene particles and can be transferred to other laboratories that analyze similar types of samples. If direct implementation is impossible, the elaborated methodologies may serve as a guide to help laboratories validating their own methods.

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