Acceleration Measurement System Research Articles

CREATION OF A UNIVERSAL MEASUREMENT COMPLEX FOR ROAD TESTS OF WHEELED VEHICLES

The results of studies related to the development of a universal measuring complex for road testing of wheeled vehicles (hereinafter referred to as the complex) are presented. The substantiation of the list of parameters measured by the complex and their metrological characteristics has been carried out, and the general requirements for the complex have been formulated; the basic principles of building special software included in the complex are given. The issues of calibration of the measuring systems of the complex are con-sidered in detail and the methods used for this, including features of the calibration method of the deceleration/ acceleration measurement system, are described. The description and technical characteristics of the developed complex are presented, as well as the results of its calibration and trial operation. On the basis of experimental studies, the expediency of using a two-stage method of calibrating path, speed and decelera-tion/acceleration measurement systems has been confirmed. As an example, the results of testing a vehicle for compliance with the requirements of UN Regulation No. 13, obtained using the complex, are shown, and the main software windows during these tests are described in detail.

スマートウォッチによる加速度計測システムの開発

It is important for disease control to grasp the amount of walking in stroke hemiplegic patients. However, it is often difficult for hemiplegic patients to measure their steps accurately with commercial pedometers. Our aim is to develop an acceleration measurement system for hemiplegic patients. In this study, we investigated the feasibility of an acceleration measurement system using a smartwatch (Fitbit Versa., Fitbit, Inc.) as an acceleration sensor and a smartphone as a data recorder.

A warning system for urolithiasis via retrograde intrarenal surgery using machine learning: an experimental study

BackgroundTo develop a warning system that can prevent or minimize laser exposure resulting in kidney and ureter damage during retrograde intrarenal surgery (RIRS) for urolithiasis. Our study builds on the hypothesis that shock waves of different degrees are delivered to the hand of the surgeon depending on whether the laser hits the stone or tissue.MethodsA surgical environment was simulated for RIRS by filling the body of a raw whole chicken with water and stones from the human body. We developed an acceleration measurement system that recorded the power signal data for a number of hours, yielding distinguishable characteristics among three different states (idle state, stones, and tissue–laser interface) by conducting fast Fourier transform (FFT) analysis. A discrete wavelet transform (DWT) was used for feature extraction, and a random forest classification algorithm was applied to classify the current state of the laser-tissue interface.ResultsThe result of the FFT showed that the magnitude spectrum is different within the frequency range of < 2500 Hz, indicating that the different states are distinguishable. Each recorded signal was cut in only 0.5-s increments and transformed using the DWT. The transformed data were entered into a random forest classifier to train the model. The test result was only measured with the dataset that was isolated from the training dataset. The maximum average test accuracy was > 95%. The procedure was repeated with random signal dummy data, resulting in an average accuracy of 33.33% and proving that the proposed method caused no bias.ConclusionsOur monitoring system receives the shockwave signals generated from the RIRS urolithiasis treatment procedure and generates the laser irradiance status by rapidly recognizing (in 0.5 s) the current laser exposure state with high accuracy (95%). We postulate that this can significantly minimize surgeon error during RIRS.

Storage System for Measuring the Impact Loadings with Mobile Terminal

We conducted a literature review and determined the specifications of an ideal virtual accelerometer in order to design an economical and portable acceleration measurement system that can be used in amateur sports. As a result, the performance of the ideal and virtual accelerometer was determined to have a sampling frequency of 1000 Hz, an acceleration of 200 G (1962 m/s2), and duration of 40 ms. The rotation tests for comparing the ideal and virtual one were conducted on three existing sensors using a rotating impact test system. The results showed that the minimum requirements were a sampling frequency of 200 Hz, a maximum acceleration of 200 m/s2 with a duration of 27 ms. If a sensor also holds，a Bluetooth® communication device, and is dimensions of 30 × 30 × 15 mm or less, it will be used in the storage system of our goal.

Application of screening using a flip-flow screen and shallow groove dense-medium separation in a steam coal preparation plant

ABSTRACT Low-rank steam coal is an important coal resource, but has high water and ash content, which needs to be separated to improve its quality and calorific value. In this paper, the process of screening using a flip-flow screen and density separator using a shallow groove dense-medium separator for steam coal was proposed and applied to the Lijiahao coal preparation plant. Kinematics of the screen box and the surface of the flip-flow screen were investigated using an acceleration and laser displacement measurement and analysis system. The mechanism of the flip-flow screen to overcome aperture blocking and to enhance the screening performance for moist and fine coal was discussed. The results from an industrial experiment when screening at 3 mm showed that the screening efficiency was 82.51%, while the total misplaced materials were 5.91%. The commercial separation of a wide size range of coal using a shallow groove dense-medium separator was analyzed. The results showed that the system exhibited satisfactory separation performance for 100–3 mm coal, whereas the corresponding Ep value was found to be 0.06 g/cm3. Compared with the 6 mm separation system, the yield of clean coal increased by 8.50%, which remarkably increased the economic benefits for the company.

Monitoring of Cow Location in a Barn by an Open-Source, Low-Cost, Low-Energy Bluetooth Tag System

Indoor localization of dairy cows is important for cow behavior recognition and effective farm management. In this paper, we propose a low-cost system for low-accuracy cow localization based on the reception of signals sent by an acceleration measurement system using the Bluetooth Low Energy protocol. The system consists of low-cost tags and receiving stations. The tag specifications and the localization accuracy of the system were studied experimentally. The received signal strength propagation model and dependence on the tag orientation was studied in an open-space and a barn environment. Two experiments for the evaluation of localization accuracy were conducted with 35 and 19 cows for two days. The localization reference was achieved from feeding stations, a milking robot and videos of cows decoded manually. The localization accuracy (mean ± standard deviation) was 3.27 ± 2.11 m for the entire barn (10 × 40 m2) and 1.9 ± 0.67 m for a smaller area (4 × 5 m2). The system can be used for recognizing long-distance walking, crowded areas in the barn, e.g., queues to milking robots, and cow’s preferable locations. The estimated system cost was 500 + 20 × (cow number) € for one barn. The system has open-access software and detailed instructions for its installation and usage.

High-Precision Acceleration Measurement System Based on Tunnel Magneto-Resistance Effect.

A high-precision acceleration measurement system based on an ultra-sensitive tunnel magneto-resistance (TMR) sensor is presented in this paper. A “force–magnetic–electric” coupling structure that converts an input acceleration into a change in magnetic field around the TMR sensor is designed. In such a structure, a micro-cantilever is integrated with a magnetic field source on its tip. Under an acceleration, the mechanical displacement of the cantilever causes a change in the spatial magnetic field sensed by the TMR sensor. The TMR sensor is constructed with a Wheatstone bridge structure to achieve an enhanced sensitivity. Meanwhile, a low-noise differential circuit is developed for the proposed system to further improve the precision of the measured acceleration. The experimental results show that the micro-system achieves a measurement resolution of 19 μg/√Hz at 1 Hz, a scale factor of 191 mV/g within a range of ± 2 g, and a bias instability of 38 μg (Allan variance). The noise sources of the proposed system are thoroughly investigated, which shows that low-frequency 1/f noise is the dominant noise source. We propose to use a high-frequency modulation technique to suppress the 1/f noise effectively. Measurement results show that the 1/f noise is suppressed about 8.6-fold at 1 Hz and the proposed system resolution can be improved to 2.2 μg/√Hz theoretically with this high-frequency modulation technique.

Electromagnetic Suspension Acceleration Measurement Model and Experimental Analysis

This paper introduces a prototype of the inertial sensor based on electromagnetic suspension. By analyzing and simulating the change of the magnetic field, the dynamic equation of proof mass has been deduced. The device has the characteristics of a high-frequency accelerometer and a vibration frequency sensor, and the horizontal and vertical frequency ranges of the magnetic suspension acceleration measurement system are 50–500 Hz and 35–650 Hz, and the acceleration measurement ranges are ±3.3 m/s 2 and ±10 m/s 2 , respectively. Compared with the MPU6050 accelerometer, this measurement method has higher sensitivity and retains more vibration acceleration information of the measured object. This paper provides a new idea for the design of the acceleration sensor.

A 120°C 20G-compliant vibration energy harvester for aeronautic environments

This paper reports the design, fabrication and testing of a piezoelectric energy harvester operating at 90°C and withstanding 120°C and 20G of acceleration. This harvester, along with its dedicated power management circuit, has been designed to supply a 3-channel Acceleration Measurement System (AMS) for the structural health monitoring of an aircraft engine. This aeronautic-compliant bimorph harvester outputs 6.83mW at 1G, up to 246mW at 8G of acceleration and exhibits a maximum Normalized Power Density of 15.3kg.s.m−3 at 90°C.

Non-contact all-fiber optic laser Doppler accelerometer.

A non-contact all-fiber optic acceleration measurement system has been proposed in this work. Using a fiber delay line in the fiber-optic path, the difference between two Doppler shifted frequencies of a laser beam corresponding to two different velocities of a moving object with a fixed time delay was measured and used for acceleration extraction. By performing acceleration measurements for a piezoelectric ceramic oscillator driven by an open-loop piezo controller at different voltages, a measurement error of better than -3.766% and nonlinearity degree of 0.314% were achieved.

Gravity acceleration measurement based on Atom interferometry

Cold atom interferometer based on two-photon stimulated Raman transition has been proved to be a promising way to measure g with higher precision. In this work, we first introduce the principle of atomic interference gravimetry, including the interaction between the atoms and light, the interferometry with the Raman beams and the measure of the g. Then our gravity acceleration measurement system will be introduced, including atomic fountain, Raman system and detection system. With this device, we can get the value of the g, with the uncertainty in the order of ten minus seven.

Dynamic responses of a steel-reinforced concrete target impacted by aircraft models

To investigate the characteristics of the impact load for a large commercial aircraft impacting upon a nuclear power plant, an integral test measurement system is developed through the experiments of aircraft models in middle sizes impacting upon a movable steel-reinforced concrete target via a rocket sled loading test platform. Three impact tests with different sizes of the aircraft models were carried out. In all the tests, the flying attitude and velocity of the aircraft models were recorded by a high-speed photography system. The acceleration and velocity time histories of the target were obtained by an acceleration measurement system and a DISAR system, respectively. The computed results of the impact loads calculated by using the measured acceleration and velocity data, respectively, are found to be in good agreement, which verified the reliability of the measurement system. Moreover, the acceleration time histories of the aircraft models were obtained by using the onboard overload storage, and, based on the measured data, the crushing load of the aircraft model can be calculated. On the other hand, the impact load time histories are also calculated by using the modified Riera equation, and the computed results are found to be consistent with that calculated by using the measured acceleration or velocity data of the target. In addition, the correction coefficient α in the modified Riera equation is also determined. Finally, an engineering calculation method and a formula to calculate the aircraft's impact load are proposed, with no need for knowing in advance the aircraft's crushing load distribution data. Moreover, the impact load of an aircraft calculated by using the engineering formula can be used in the evaluation on the impact resistance of the structure in a nuclear power plant, and the evaluation results will be impulse conservative.

Analysis of Vibratory Data Collected by the Space Acceleration Measurement System (SAMS) on Blue Origin, June 19, 2016

Abstract On Sunday, June 19, 2016, a Space Acceleration Measurement System triaxial sensor head flew on a suborbital flight aboard Blue Origin's New Shepard vehicle to collect precision vibratory accelerometry data. The Space Acceleration Measurement System (SAMS) sensor head was mounted inside of a Blue Origin single payload locker inside of the crew capsule. This paper describes the configuration, capture, and analysis of the SAMS data from this flight along with other, related flight log information provided by Blue Origin. Three overlapping periods during the flight were identified and characterized to provide future users of the platform with insight into options that may prove suitable for their research needs. Average accelerations in the Post-Separation Period were consistent with other low-g research platforms, while the shorter Microgravity Period in the middle of the flight showed ultra-quiet vibratory acceleration environments. Researchers can consider this microgravity quality versus time a tradeoff in their experimental designs.

101 心地よい揺らぎに関する基礎研究 : 人が心地よく体を動かしている時の周期ゆらぎに関する考察(騒音・振動の評価・改善技術(1))

It is necessary to examine comfortable vibrations and swinging motions used in the development of a human-machine interface. The author focused on the period fluctuations of rhythms produced by humans for their own enjoyment. The rhythms occurring when walking comfortably, hopping on a pogo stick, bouncing on an exercise ball, swinging on a swing, and dribbling a basketball were measured using a portable acceleration measurement system or a sound recording system. Then, periods of the rhythms were obtained, and the power spectra were examined. As a result, the power spectra showed a downward slope within a low-frequency range; that is, they are similar to the property of 1/f. In this study, the results of the frequency analysis were examined and compared. It was clarified that these power spectra have about the same magnitude, the periods are about the same, and the period fluctuations are not very large.

Implementation of a New Digital Grating Angular Acceleration Measurement System Based on FPGA and its Error Analysis

Shaft angular acceleration is one of the most important parameter of rotary machines, the designation and implementation of a new angular acceleration measurement system is proposed in this paper. First, the speed signal is acquired through grating and infrared photocell, then interpolation speed signal with high-frequency pulses, so as to convert speed signals to pulses, last, angular acceleration is received by processing these pulses. This measurement system combined with FPGA and SCM, the function of FPGA are generating pulses、interpolating speed signal and counting the number of pulses, the result of count is processed by SCM. The high accuracy of measurement system is verified accord to the test.and the causes of errors are received by theoretical analysis.

파랑유발 극미세 진동모니터링에 의한 실물 케이슨식 방파제의 진동특성 분석

최근, 태풍, 지진해일 등 극한 외력 상황에 대응하는 해안 항만 구조물의 안전성에 대한 관심이 고조되고 있다. 케이슨 방파제 구조물은 해저 지반 위에 설치된 중력식 구조물로서, 항내 정온도 확보를 위해 외해로부터 입사해오는 파랑을 차단하는 기능을 한다. 이 같은 케이슨 방파제의 구조안전성을 모니터링 하기 위해 진동응답 기반의 기법에 대한 연구가 활발히 수행되고 있다. 본 연구에서는 실물 케이슨 방파제 구조물의 안전성평가를 위한 기초연구로서, 파랑유발 극미세 진동(micro-vibration) 계측을 통해 케이슨 방파제의 진동응답을 계측하고 진동 특성치를 분석하는 체계를 제시하였다. 이를 위해 첫째, 케이슨 방파제의 진동특성 분석 기법을 선정하였다. 둘째, 대상 구조물로서 부산항 오륙도 케이슨식 방파제를 선정하였다. 셋째, 케이슨으로부터 파랑유발 극미세 진동응답을 계측하였다. 마지막으로, 계측된 극미세 진동응답을 이용하여 케이슨 방파제의 진동특성을 분석하였으며, 본 연구에서 제시한 파랑유발 미세 진동 모니터링 기법의 적용성을 검증하였다. In this study, the wave-induced micro-vibration monitoring scheme is proposed to analyze vibration characteristics of real caisson-type breakwater. To produce the basic information on vibration-based structural safety assessment of caisson structural system, the following approaches are implemented. Firstly, vibration response analysis methods are selected to examine modal characteristics of caisson structure. Secondly, Oh-Ryuk-do caisson-type breakwater is selected as the real caisson structure. Thirdly, wave-induced micro-vibration responses are measured by wireless acceleration measurement system. Finally, vibration characteristics of the real caisson are analyzed for the purpose of utilizing them for structural safety assessment and of evaluating the practicality of the proposed micro-vibration monitoring scheme for caisson-type breakwater.

Design of MEMS accelerometer based acceleration measurement system for automobiles

Design of an acceleration measurement system using a MEMS accelerometer to measure acceleration of automobiles in all the three axes is presented. Electronic stability control and anti-lock breaking systems in automobiles use the acceleration measurements to offer safety in driving. The system uses an ARM microcontroller to quantize the outputs of accelerometer and save the measurement data on a microSD card. A LabVIEW program has been developed to analyze the longitudinal acceleration measurement data and test the measurement system. Random noises generated and added with measurement data during measurement are filtered by a Kalman filter implemented in LabVIEW. Longitudinal velocity of the vehicle is computed from the measurement data and displayed on a graphical chart. Typical measurement of velocity of a vehicle at different accelerations and decelerations is presented.

Validation of a Wireless Head Acceleration Measurement System for Use in Soccer Play

Soccer heading has been studied previously with conflicting results. One major issue is the lack of knowledge regarding what actually occurs biomechanically during soccer heading impacts. The purpose of the current study is to validate a wireless head acceleration measurement system, head impact telemetry system (HITS) that can be used to collect head accelerations during soccer play. The HIT system was fitted to a Hybrid III (HIII) head form that was instrumented with a 3-2-2-2 accelerometer setup. Fifteen impact conditions were tested to simulate impacts commonly experienced during soccer play. Linear and angular acceleration were calculated for both systems and compared. Root mean square (RMS) error and cross correlations were also calculated and compared for both systems. Cross correlation values were very strong with r = .95 ± 0.02 for ball to head forehead impacts and r = .96 ± 0.02 for head to head forehead impacts. The systems showed a strong relationship when comparing RMS error, linear head acceleration, angular head acceleration, and the cross correlation values.

Application testing of a new three-dimensional acceleration measuring system with wireless data transfer (WAS) for behavior analysis

A wireless acceleration measurement system was applied to free-moving cows and horses. Sensors were available as a collar and a flat box for measuring leg or trunk movements. Results were transmitted simultaneously by radio or stored in an 8-MB internal memory. As analytical procedures, frequency distributions with standard deviations, spectral analyses, and fractal analyses were applied. Bymeans of the collar sensor, basic behavior patterns (standing, grazing, walking, ruminating, drinking, and hay uptake) could be identified in cows. Lameness could be detected in cows and horses by means of the leg sensor. The portion of basic and harmonic spectral components was reduced; the fractal dimension was reduced. The system can be used for the detection and analysis of even small movements of free-moving humans or animals over several hours. It is convenient for the analysis of basic behaviors, emotional reactions, or events causing flight or fright or for comparing different housing elements, such as floors or fences.

Ground based ISS payload microgravity disturbance assessments

In order to verify that the International Space Station (ISS) payload facility racks do not disturb the microgravity environment of neighboring facility racks and that the facility science operations are not compromised, a testing and analytical verification process must be followed. Currently no facility racks have taken this process from start to finish. The authors are participants in implementing this process for the NASA Glenn Research Center (GRC) Fluids and Combustion Facility (FCF). To address the testing part of the verification process, the Microgravity Emissions Laboratory (MEL) was developed at GRC. The MEL is a 6 degree of freedom inertial measurement system capable of characterizing inertial response forces (emissions) of components, sub-rack payloads, or rack-level payloads down to 10 - 7 g 's. The inertial force output data, generated from the steady state or transient operations of the test articles, are utilized in analytical simulations to predict the on-orbit vibratory environment at specific science or rack interface locations. Once the facility payload rack and disturbers are properly modeled an assessment can be made as to whether required microgravity levels are achieved. The modeling is utilized to develop microgravity predictions which lead to the development of microgravity sensitive ISS experiment operations once on-orbit. The on-orbit measurements will be verified by use of the NASA GRC Space Acceleration Measurement System (SAMS). The major topics to be addressed in this paper are: (1) Microgravity Requirements, (2) Microgravity Disturbers, (3) MEL Testing, (4) Disturbance Control, (5) Microgravity Control Process, and (6) On-Orbit Predictions and Verification.