A Six Degree of Freedom Head Acceleration Measurement Device for Use in Football

2011 ◽  
Vol 27 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Steven Rowson ◽  
Jonathan G. Beckwith ◽  
Jeffrey J. Chu ◽  
Daniel S. Leonard ◽  
Richard M. Greenwald ◽  
...  
Keyword(s):  
Degree Of Freedom ◽  
Head Acceleration ◽  
Wireless Data ◽  
Measurement Device ◽  
Football Helmet ◽  
Wireless Data Transmission ◽  
Hybrid Iii ◽  
Football Helmets ◽  
High Incidence Rate ◽  
Six Degree Of Freedom

The high incidence rate of concussions in football provides a unique opportunity to collect biomechanical data to characterize mild traumatic brain injury. The goal of this study was to validate a six degree of freedom (6DOF) measurement device with 12 single-axis accelerometers that uses a novel algorithm to compute linear and angular head accelerations for each axis of the head. The 6DOF device can be integrated into existing football helmets and is capable of wireless data transmission. A football helmet equipped with the 6DOF device was fitted to a Hybrid III head instrumented with a 9 accelerometer array. The helmet was impacted using a pneumatic linear impactor. Hybrid III head accelerations were compared with that of the 6DOF device. For all impacts, peak Hybrid III head accelerations ranged from 24 g to 176 g and 1,506 rad/s2to 14,431 rad/s2. Average errors for peak linear and angular head acceleration were 1% ± 18% and 3% ± 24%, respectively. The average RMS error of the temporal response for each impact was 12.5 g and 907 rad/s2.

The Study of Wireless Measurement System for Neuro-Motor Reaction Time

2012 ◽  
Vol 472-475 ◽  
pp. 2850-2853
Author(s):  
Shu Gang Li ◽  
Zhi Wu Zhu ◽  
Fei Shen
Keyword(s):  
Reaction Time ◽  
Measurement System ◽  
Data Transmission ◽  
Wireless Data ◽  
Measurement Device ◽  
The Core ◽  
Front End ◽  
Wireless Data Transmission ◽  
Reaction Time Measurement ◽  
Wireless Measurement

The purpose of this study was to introduce the design and realization about a measurement system, which is based by accelerometer ADXLl05 and wireless data-transmission module for starting line of athlete’s reaction time. This system plotted curves of players’ reaction time using 89C205l as the core of the front-end of the system reaction time measurement device, the measurement device take real-time captures players' reaction time, and then sent over the wireless data-transmission module player reaction time to the PC machine to display, and to record the reaction time.

Complete parameter identification of parallel manipulators with partial pose information using a new measurement device

Robotica ◽  
2004 ◽  
Vol 22 (6) ◽  
pp. 689-695 ◽  
Author(s):  
Abdul Rauf ◽  
Sung-Gaun Kim ◽  
Jeha Ryu
Keyword(s):  
Parallel Manipulators ◽  
Error Reduction ◽  
Initial Guess ◽  
Significant Error ◽  
Degree Of Freedom ◽  
Kinematic Parameters ◽  
Measurement Device ◽  
End Effector ◽  
Six Degree Of Freedom ◽  
Noisy Measurements

A new measurement device is proposed for the calibration of parallel manipulators that can be used to indentify all kinematic parameters with partial pose measurements. The device while restricting the motion of the end-effector to five degree-of-freedom measures three components of posture. A study is performed for a six degree-of-freedom fully parallel Hexa Slide Manipulator. Intrinsic inaccuracies of the measurement device are modeled with two additional identification parameters. Computer simulations show that all parameters, including the additional parameters, can be identified. Results show a significant error reduction, even with noisy measurements, and reveal that the identification is robust against errors in initial guess.

Improvement and Experiment for Online Measurement of Droplet Mass Deposit

2021 ◽  
Vol 64 (4) ◽  
pp. 1345-1354
Author(s):  
Chengda Sun ◽  
Weimin Ding ◽  
Changding Liu ◽  
Weifeng Yao ◽  
Lilian Shi
Keyword(s):  
Relative Error ◽  
Data Transmission ◽  
Online Measurement ◽  
Tracer Method ◽  
Wireless Data ◽  
Measurement Device ◽  
Wireless Data Transmission ◽  
Data Transmission System ◽  
Measurement Devices ◽  
Original Device

HighlightsA measurement device for droplet mass deposit was improved to enhance its performance.A wireless data transmission system was used to achieve convenient data sharing.A user interface was designed for display and analysis of the measurement results.A positioning mechanism was designed for arranging measurement devices promptly.Abstract. Measurement of droplet mass deposit is important in spray research and spray performance evaluation. In this article, an online measurement device for droplet mass deposit was improved based on the original design. The measurement resolution, precision, and data stability were improved by optimization of the structure and components and by data filtering. The resolution reached 0.00067 mg cm-2. Comparison tests showed that the relative error between the original device and an analytical balance was 6.68% to 8.48%, and the relative error between the improved device and the analytical balance was 5.24% to 6.15%. Compared with the original device, the relative error decreased and the precision improved. The relative error between the improved device and a tracer method was 5.11% to 6.99%, and the precision of the improved device was close to that of the tracer method. A positioning mechanism was designed to arrange measurement devices promptly in the test area, and a wireless data transmission system was used to achieve convenient data sharing. A user interface was designed to display the results in the form of tables and contour maps. Tests were conducted to measure the droplet mass deposit distribution of one nozzle, the droplet mass deposit distribution in a tree canopy, and the uniformity of the droplet mass deposit distribution in a small horizontal area. The results showed that the improved measurement device could provide data promptly and conveniently for spray research and spray performance evaluation. Keywords: Device improvement, Mass distribution, Wireless communication.

The Effects of Helmet Weight on Hybrid III Head and Neck Responses by Comparing Unhelmeted and Helmeted Impacts

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Ron Jadischke ◽  
David C. Viano ◽  
Joe McCarthy ◽  
Albert I. King
Keyword(s):  
Head And Neck ◽  
Test Series ◽  
Head Acceleration ◽  
Impact Tests ◽  
Football Helmet ◽  
Independent Test ◽  
Hybrid Iii ◽  
Pendulum Impact

Most studies on football helmet performance focus on lowering head acceleration-related parameters to reduce concussions. This has resulted in an increase in helmet size and mass. The objective of this paper was to study the effect of helmet mass on head and upper neck responses. Two independent test series were conducted. In test series one, 90 pendulum impact tests were conducted with four different headform and helmet conditions: unhelmeted Hybrid III headform, Hybrid III headform with a football helmet shell, Hybrid III headform with helmet shell and facemask, and Hybrid III headform with the helmet and facemask with mass added to the shell (n = 90). The Hybrid III neck was used for all the conditions. For all the configurations combined, the shell only, shell and facemask, and weighted helmet conditions resulted in 36%, 43%, and 44% lower resultant head accelerations (p < 0.0001), respectively, when compared to the unhelmeted condition. Head delta-V reductions were 1.1%, 4.5%, and 4.4%, respectively. In contrast, the helmeted conditions resulted in 26%, 41%, and 49% higher resultant neck forces (p < 0.0001), respectively. The increased neck forces were dominated by neck tension. In test series two, testing was conducted with a pneumatic linear impactor (n = 178). Fourteen different helmet makes and models illustrate the same trend. The increased neck forces provide a possible explanation as to why there has not been a corresponding reduction in concussion rates despite improvements in helmets ability to reduce head accelerations.

Diagnostic System of Gravitational Solid Flow Based on Weight and Accelerometer Signal Analysis Using Wireless Data Transmission Technology

2012 ◽  
Vol 17 (4) ◽  
pp. 319-326 ◽  
Author(s):  
Zbigniew Chaniecki ◽  
Krzysztof Grudzień ◽  
Tomasz Jaworski ◽  
Grzegorz Rybak ◽  
Andrzej Romanowski ◽  
...  
Keyword(s):  
Signal Analysis ◽  
Scale Up ◽  
Three Dimensional ◽  
Diagnostic System ◽  
Wireless Data ◽  
Stick Slip ◽  
Wireless Data Transmission ◽  
Accelerometer Signal ◽  
Flow Investigation ◽  
Material Information

Abstract The paper presents results of the scale-up silo flow investigation in based on accelerometer signal analysis and Wi-Fi transmission, performed in distributed laboratory environment. Prepared, by the authors, a set of 8 accelerometers allows to measure a three-dimensional acceleration vector. The accelerometers were located outside silo, on its perimeter. The accelerometers signal changes allowed to analyze dynamic behavior of solid (vibrations/pulsations) at silo wall during discharging process. These dynamic effects are caused by stick-slip friction between the wall and the granular material. Information about the material pulsations and vibrations is crucial for monitoring the interaction between silo construction and particle during flow. Additionally such spatial position of accelerometers sensor allowed to collect information about nonsymmetrical flow inside silo.

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