Thesis (doctoral)--Tampere University of Technology, 2009. / Includes bibliographical references. Also available on the World Wide Web.

Thesis (M.S.)--University of Delaware, 2009. / Principal faculty advisor: David A. Barlow, Dept. of Health, Nutrition, & Exercise Sciences. Includes bibliographical references.

Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2005 / Having simple structure and high sensitivity, micro accelerometer is a type of popular transducer used to measure the acceleration in a great variety of conditions. The bridge-type micro accelerometer is a typical micro accelerometer and has many types. As one of research project of Kentron in South Africa, the thesis presented here analyzes the bridge-type capacitive nticro accelerometer (BTCMA) and the bridge-type micro accelerometer with two piezoelectric thin films read-out (BTPMA). In this thesis, the similar structures are used on BTCMA and BTPMA For proving the fundamental mode of the structure can measure acceleration and utilizing the structural and electric characteristic to avoid the effect of higher modes, the program CoventorWare for nticro-electric-mechanical system (MEMS) design and analysis is used here to analyze the modes of these two structures, The two group piezoelectric thin films of BTPMA can be connected in serial or parallel configurations. Integrating piezoelectric effect method, strength method and energy method, the analytical analysis of these two configurations has been done with particular emphasis on the elastic characteristics of the thin films. The analytical formulas of transducer, sensitivity, resonance frequency, noise, quality factor, ntinimum detectable signal and maximum detectable range are obtained. According to the comparison results between these two configurations, the charge output in parallel configuration is a little more than that in serial configuration and the sensitivity in serial configuration is much higher than that in parallel configuration. Finally, a calculation of certain practical nticro accelerometer size is used to prove the above conclusions. On the base of capacitance theory, strength method and energy method, the analytical analysis of the BTCMA has been done in this thesis.

Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2005. / Due to an increasing in industrial micromation need in recent years, the use of micro accelerometers has been highly increased. Consecutively, this has promoted research activities in this field; capacitive accelerometers also have got high concern at large. As a research project of the Kentron in South Africa, this thesis deals with a theoretical model for a one-dimensional micro capacitive accelerometer with U-shape cantilever beam. The properties of the small angle tilted-plate capacitor have been analyzed; the capacitance equation and electrostatic force equation of this kind capacitor have been derived. The sensing element of this accelerometer consists of an inertial mass connected with two cantilever beams. The vibration modes analysis to the sensing element was accomplished by using CoventorWare2004's MemMech module, the result indicates that the main vibration mode can cause the capacitance change observably and the effect of the other modes to the capacitance can be ignored, which satisfied the purpose of the design. In the process of deriving the linearizing acceleration equation, the angle of the inertial mass caused by the deformation of the U-shape cantilever beam was taken into account as well as the electrostatic force between the two electrodes, thus the more precise acceleration linear equation was obtained. The sensitivity equation was derived through the acceleration linear equation, the relationship between the main parameters of the system and the sensitivity has been analyzed. The differential structure of this micro capacitive accelerometer was also analyzed; the linearizing acceleration equation and sensitivity equation of this kind structure were derived, it has been proven that the sensitivity of this structure is twice than the normal structure approximately. The maximum detectable signal was obtained in terms of the fracture strength of the cantilever beam and the maximum displacement of the inertial mass. The minimum detectable signal was obtained in terms of the thermal noise analysis. In the process of the dynamic analysis, the forced vibration produced by the sinusoidal periodic force and sinusoidal periodic moment was analyzed and the transient capacitance equation was derived, this proved the system has good dynamic character in theory. The system was simulated and analyzed by using CoventorWare2004's Saber module. The initial capacitance analysis indicates the relationship between the voltage and the initial capacitance, the result is close to the analytic model. The resonance frequencies analysis indicates that the main dimensions of the sensing element can determine the resonance frequencies and each vibration mode's sequence, the initial dimensions of the sensing element was proved reasonable by analyzing. Sensitivity analysis and Monte Carlo analysis indicate the effect of the sensing element's normal manufacturing tolerance to the system's frequency is small. Impact of plate curvature analysis indicates the effect of the inertial mass's deformation caused by the surface stress to the capacitance is small. Transient analysis obtained the system's transient displacement curve of six directions and transient capacitance curve in normal terms; this proved the system has good dynamic character in the simulating environment.

M.Ing. / Measurement of acceleration is of importance for several applications such as impact tests and navigation. The design and manufacture of a symmetrical piezoresistive accelerometer, which can measure accelerations up to 60 000 g, are presented in this work. Various accelerometers are discussed and compared. The design of an accelerometer is an interdisciplinary activity which requires knowledge of the mechanical and electronic properties of materials as well as electronic signal processing. Computer design aids such as finite element analysis and semiconductor process modelling are used in this work to optimize first order designs. Since accelerometers with large dynamic range must be small in size in order to cause the minimum disturbance of the measurand, micromachining of silicon is used to manufacture extremely small devices. A substantial part of this work deals with the different materials and methods used in the manufacturing process. Since there is an inevitable spread in the parameters of the accelerometers, each one requires calibration. A test facility was developed to test and calibrate accelerometers up to 20 000 g. Because shock impulse response is determined by the test facility, a Fourier-transform is used to compute the frequency response of the accelerometer. The result of this work is the development and manufacture of an accelerometer with a mass of approximately 1 mg. The extremely small size and mass makes it very useful for measuring high accelerations.

The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument, under development for the Subaru Telescope, has currently the fastest on-sky wavefront control loop, with a pyramid wavefront sensor running at 3.5 kHz. But even at that speed, we are still limited by low-frequency vibrations. The current main limitation was found to be vibrations attributed mainly to the rotation of the telescope. Using the fast wavefront sensors, cameras and accelerometers, we managed to identify the origin of most of the vibrations degrading our performance. Low-frequency vibrations are coming from the telescope drive in azimuth and elevation, as well as the elevation encoders when the target is at transit. Other vibrations were found at higher frequency coming from the image rotator inside Subaru's adaptive optics facility AO188. Different approaches are being implemented to take care of these issues. The PID control of the image rotator has been tuned to reduce their high-frequency contribution. We are working with the telescope team to tune the motor drives and reduce the impact of the elevation encoder. A Linear Quadratic Gaussian controller (LQG, or Kalman filter) is also being implemented inside SCExAO to control these vibrations. These solutions will not only improve significantly SCExAOs performance, but will also help all the other instruments on the Subaru Telescope, especially the ones behind A0188. Ultimately, this study will also help the development of the TMT, as these two telescopes share very similar drives.

Orientador: Luiz Eduardo Barreto Martins / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação Física / Made available in DSpace on 2018-08-26T17:43:58Z (GMT). No. of bitstreams: 1 LattesFerreira_MariaFernanda_M.pdf: 1902777 bytes, checksum: 9859b148c18b9fce39e4204cdc6a7b8b (MD5) Previous issue date: 2014 / Resumo: O presente trabalho teve como objetivo é identificar as variáveis biomecânicas na largada do ciclismo de velocidade obtidas pelo o acelerômetro contido num sistema inercial de navegação denominado SM-MAE construído no Laboratório de Sensores Microeletrônicos da Faculdade de Engenharia Elétrica e de Computação da Unicamp, para isso foi necessário dividir esse trabalho em duas partes. A primeira parte teve como objetivos desenvolver metodologia adequar o uso do acelerômetro SM-MAE para aquisição de variáveis biomecânicas, comparar seus dados com dados provindos da cinemetria e de um acelerômetro comercial e, descreve as etapas de tratamento do sinal de aceleração. Para isso participaram de dois ciclistas amadores, os quais executaram dois tiros de 50m em uma raia plana demarcada, em piso de asfalto, usando uma bicicleta própria da modalidade, com o sistema nela instalado. Concomitante ao sistema foram usadas duas câmeras digitais filmaram a fullHd com frequência de aquisição de 60Hz para realização da cinemetria e um o acelerômetro comercial (Xsens). Através do rastreamento manual e a reconstrução unidimensional dos dados, obteve-se a posição da bicicleta e em seguida adquiriu-se à distância percorrida e suas derivadas. O processamento do sinal, rastreamento e rotinas para identificação das acelerações e suas integrais foram feitas no software Matlab. Para comparar o acelerômetro SM-MAE com outros sistemas, foi realizado comparações gráficas. Observou-se que os resultados obtidos se assemelhavam aos da cinemetria e aos do acelerômetro comercial. Portanto, a metodologia aplicada nesta pesquisa possibilitou a realização da segunda etapa deste trabalho, que teve como objetivo identificar as variáveis biomecânicas fornecidas pelo SM-MAE relacionando-as com o desempenho do ciclista num teste de 30 metros em velódromo e caracterizar dos padrões das acelerações de largada dos aletas envolvidos nesse estudo. Para isso contou com cinco ciclistas de alto rendimento que realizaram 3 sprints de 30m cada um e o acelerômetro (SM-MAE) foi fixado no quadro da bicicleta no velódromo. Como resultado na comparação entre as variáveis de aceleração não foi identificado diferenças significativas para todas elas entre os voluntários e nem entre as repetições. A velocidade máxima de cada ciclo e a velocidade máxima total de cada sprint, obteve-se diferença significativa entre os atletas, destacando A1 e A3.Na variável tempo final (TT), foi possível identificar alta correlação positiva com tempo de soma dos dois ciclos de pedal (T2), com a velocidade máxima (Vmax), TC1(tempo do primeiro ciclo de pedalada), aceleração negativa máxima (ANmax), média do vale da aceleração negativa (MvaleAN) e teve relação TC1 com T2 e T2 com MvaleAN. E também relação entre Vmáx com ANmax e MvaleAN. Conclui-se que o SM-MAE é capaz de detectar sutilezas técnicas na largada do ciclismo de pista auxiliando o diagnóstico da capacidade atlética como do programa de treinamento / Abstract: The present work is aimed to identify the biomechanical variables at the start of cycling speed obtained by the accelerometer contained in an inertial navigation system called SM-MAE built in Sensors Laboratory of Microelectronics School of Electrical and Computer Engineering at Unicamp, for it was necessary to divide the work into two parts. The first part aimed to develop a methodology to tailor the use of the accelerometer SM-MAE for the acquisition of biomechanical variables, compare their data with data coming from the kinematics and a commercial accelerometer and outlines the steps of processing the acceleration signal. For that participated in two amateur cyclists, who carried two shots from 50m on a flat streak demarcated in asphalt floor, using their own bike mode, with the system installed in it. Concomitant to the system were used two digital cameras filmed the FullHD with acquisition frequency of 60Hz to perform the kinematics and the commercial accelerometer (Xsens). Through the manual tracking and one-dimensional reconstruction of the data, we obtained the position of the bike and then got to the distance traveled and your derivadas. O signal processing, tracking and identification routines for the accelerations and their integrals were made Matlab. To compare the accelerometer SM-MAE with other systems, graphical comparisons was performed. It was observed that the results obtained were similar to those of the kinematics and of the commercial accelerometer. Therefore, the methodology applied in this research enabled the realization of the second stage of this study, which aimed to identify the biomechanical variables supplied by SM-MAE relating them to the performance of the rider in a 30 meter velodrome test and characterize the patterns of accelerations the start of this study involved fins. For that featured five high performance cyclists who performed three sprints of 30m each and the accelerometer (SM-MAE) was fixed to the bicycle frame at the velodrome. As a result of comparing the variables of acceleration was not identified significant differences between all these subjects nor between repetitions. The maximum speed of each cycle and the total maximum speed of each sprint, we obtained a significant difference between athletes, highlighting A3.Na A1 and end time variable (TT), it was possible to identify high positive correlation with time sum of two cycles pedal (T2), with the maximum velocity (Vmax), TC1 (time of the first cycle of pedaling), maximum negative acceleration (ANmax), average worth of negative acceleration (MvaleAN) and had TC1 compared with T2 and T2 MvaleAN . And also with ANmax relationship between Vmax and MvaleAN. We conclude that the SM-MSA is able to detect technical subtleties at the start of the track cycling aiding the diagnosis of athletic ability as the training program / Mestrado / Biodinamica do Movimento e Esporte / Mestra em Educação Física

There is a need to examine the difference in the relationship between oxygen uptake (VO2) and output from hip- and wrist-worn accelerometers in adults with Down syndrome (DS). The purpose of this study is to identify if that relationship is different between adults with and without DS. Hip- and wrist-worn accelerometer accuracy was also assessed. The sample included 16 adults with DS (10 men; age 31±15 years) and 19 adults without DS (10 men; age 24±6 years). We measured VO2 with a portable spirometer and accelerometer output (Vector Magnitude [VM]) with a hip- and a wrist-worn accelerometer. VM and group were significant predictors of VO2 (p?0.021). BMI became a significant predictor in the second model and DS was no longer significant for both accelerometer models. The Bland-Altman plots indicated nearly zero mean error for both groups. Hip-worn accelerometers showed greater accuracy, and showed less error based on 95% confidence intervals.

No description available.

Matrix variate distributions present a innate way to model random matrices. Realiza- tions of random matrices are created by concurrently observing variables in different locations or at different time points. We use a finite mixture model composed of matrix variate normal densities to cluster matrix variate data. The matrix variate data was generated by accelerometers worn by children in a clinical study conducted at McMaster. Their acceleration along the three planes of motion over the course of seven days, forms their matrix variate data. We use the resulting clusters to verify existing group membership labels derived from a test of motor-skills proficiency used to assess the children’s locomotion. / Thesis / Master of Science (MSc)