This study presents the initial study for a new approach to visualize an acoustic sound aimed at mimicking the traveling wave propagation of the basilar membrane within the human cochlea. Typically, a fast Fourier transform (FFT) is required to extract the frequency information from acoustic sound (i.e., voice) for speech recognition. Although this algorithm ensures real-time frequency extraction due to the inherent fast recursive structure, it is necessary to develop a new frequency selectivity technique for advanced speech recognition. We explore the potential of the cochlea-inspired sound visualization to deliver new frequency selectivity by using an image sensor. The experimental prototyping model is fabricated, and we capture images of frequency dependent wave propagation motion using a camera and reproduce 2D images through motion magnification. This approach offers a promising application for speech recognition systems because no FFT is required to extract the frequency information, although there are outstanding technical problems that need to be further examined.
KEYWORDS: Visualization, Edge detection, Ultraviolet radiation, Speech recognition, Composites, Particles, Digital cameras, Detection and tracking algorithms, Scanning electron microscopy, RGB color model
This preliminary study presents a sound wave visualization method using mechanoluminescent composite diaphragms made of mechanoluminescence particles (SAO). To visualize the acoustic wave, the concept of Cymatics is used to make the sound waves and vibrations observable (the human sense of vision), as it is the most discriminating human sense. The goal of this study is eventually to extract the frequency information from images captured by compact image sensors without fast Fourier transform (FFT) whereas most previous studies on sound visualization focus on a technique used to enhance the understanding of acoustical behaviors, such as reflection, diffraction, and interference. In this study, highly pressure-sensitive mechanoluminescent diaphragms will be fabricated and used to produce the images in response to audible sound excitation such as speech. This initial study will offer the potential application for new means of speech recognition principle because a systematic visual perception of the isolated speech words can be achieved using the proposed sound visualization method.
This paper presents the preliminary study on new optical pressure sensor based on a Fabry-Perot interferometer (FPI) combined with mechnoluminescence diaphragm, which emits mechnoluminescent light when mechanical stimulation (in this study, alternating pressure) is applied. The FPI is a superposition of light reflected by two parallel reflective surfaces (i.e.: thin mirrors) and shows the wavelength change due to cavity changes. The optical device is often called an interferometer which the distance between the two surfaces (i. e, resonance length) changes. Fiber-optic Fabry–Perot (FOPF) pressure sensor uses this interference phenomenon by attaching a flexible diaphragm at the end surface of interferometer. When the pressure is applied to the diaphragm, distance between the two surfaces inside FOFP sensor can change. As a result, the external pressure can be detected either by measuring these interferences using a spectrometer or by capturing using a camera module with image processing. In this study, we explore the possibility of using ML diaphragm made of SrAl2O4:Eu2+,Dy3+ (SAO) powder as new diaphragm. ML diaphragm is thin composite and can emit green mechanoluminescent light (520nm) when the alternating pressure is applied. Spectral response turned out to be then changed and related to the magnitude of applied pressure.
This paper presents a new estimation method of tire stiffness based in improved Kalman filter of vehicle suspension control system. In recent years, the need for systems monitoring the current pressure in pneumatic tires has grown dramatically. Incorrect pressured tire will affect the handling performance, tire life time and fuel economy. For these reasons, tire pressure monitoring system(TPMS) is required to ensure the vehicle safety and ride quality. However, traditional TPMS requires a battery in each tire in order to power the sensor and circuits inside the tire and it has temperature dependent capacity problem. To overcome this problem, indirect methods are proposed. One of the promising indirect methods is the sensor fusion method from automotive control systems. In this study, adaptive extended Kalman filter(AEKF) approach is proposed to identify structural parameter, such as tire stiffness. Simulation results demonstrate that proposed approach is capable of estimating tire pressure based on experiment of relation between tire pressure and tire stiffness.
This paper presents the preliminary study on monitoring of intraocular pressure (IOP) of human eye by using optical coherence tomography (OCT). Because hypertension IOP can lead to Glaucoma, one of chronic diseases of the optic nerve, the periodic monitoring of IOP through tonometry is essential to prevent the Glaucoma. One of the most common tonometry methods to estimate IOP includes measuring corneal deflection by using either a direct contact or non-contact (e.g. air puff) impact force. However, this approach may be harmful to human eye. Therefore, it is necessary to develop the more reliable and safe monitoring method. In ophthalmology, the differentiation of open-angle glaucoma and normal eyes is used to monitor the IOP by using. Typically, peripapillary vessel density or superficial perifoveal macular vessel density measurements are currently utilized. In this study, optical OCT images of bovine eye was captured with different IOPs of bovine and analyzed to extract the signature where defines the relationship between IOP and optical OCT images.
This paper presents the new G-Fresnel lens-based μ-spectrometer with an image-processing algorithm, such as a color space conversion, in the range of visible light. The proposed μ-spectrometer is developed by using the cost-effective and compact G-Fresnel lens, which diffuses the mixed visible light into the spectrum image, and an image processing algorithm. The RGB color space commonly used in the image signal from CMOS type image sensor is converted into the HSV color space, which is one of the most popular methods to express the color as the numeric value, Hue (H), Saturation (S), and Value (V), using the color space conversion algorithm. Because the HSV color space has the advantages of expressing not only the three primary color of light as the H-value, but also its intensity as the V-value, it was possible to obtain both the wavelength and intensity information of the visible light from its spectrum image. The proposed μ-spectrometer yielded an inverse linear sensitivity (hue vs. the wavelength). We demonstrated the potential of G-Fresnel lens-based μ-spectrometer for the wavelength measurement of visible light such as mechanoluminescence (ML), typically green light across the region of 500 nm.
This paper presents the preliminary study on the fluid-structure interaction (FSI) analysis of dynamic intraocular pressure (IOP) in the human eye. Because Glaucoma, a chronic disease of the optic nerve, can lead to blindness, the monitoring of IOP through tonometry is essential to prevent the increase of IOP. One of the most common tonometry methods to estimate IOP includes measuring corneal deflection by using either a direct contact or non-contact (e.g. air puff) impact force. Then, the dynamic characteristics of IOP should be investigated for improved correlation to IOP monitoring systems. In this paper, we develop a finite element model of a human eye as a spherically shaped structure filled with inviscid pressurized fluid to solve a problem of a fluid-coupled structural interaction of eye. The structural shape effects due to change in IOP are examined, and the proposed model is modified to further examine by including the mechano-luminescence (ML) membrane acting as IOP monitoring element. The effect of biomechanical parameters such as the ML membrane thickness is investigated based on the air puffy type applanation tonometry models.
This paper presents the preliminary study on the dynamic characteristics of the basilar membrane (BM) within the cochlea of inner ear. The BM is a vibrating element that varies in width and stiffness like a string on an instrument. While low frequency sounds vibrate near the apex (at the maximum length), high frequency sounds vibrate near the base of the cochlea (near the round and oval windows). Over the last decades, this frequency selectivity has been utilized for acoustic transducers by mimicking the cochlea tonotopy: passive frequency selectivity and transform from acoustic sound into frequency signal of hair cells in the organ of Corti. In previously reported studies, the frequency selectivity was simply achieved by physical parameters, such as length and thickness of beam array although the motion of the BM is generally described as a traveling wave. In this study, fluid-structure coupled acoustic analysis of vibrating BM within the cochlea of inner ear is performed to describe the actual motion of BM. The new approach different from the cantilever beam array –based approach will be then investigated for improved frequency selectivity.
This paper deal with a semi-active type bush design and magnetic analysis associated with the magnetorheological elastomer. It is focused on the magnetic field intensity analysis with 3 coil structure. The bush design consists of 3 coil structure of the bush in order to apply the magnetic field. As a result of first investigation, it is found that MRE thickness and electric current are most important parameters to design an effective bush. From the magnetic analysis, it is identified that the magnetic permeability of the MRE is lower than MR fluid. In addition, the bush model is formulated to have the uniformity of the magnetic flux and intensity field distribution.
The eardrum (also known as tympanic membrane, TM) in human auditory system has a curved conical shape with the apex pointing medially. It generally receives airborne sound waves collected by the outer ear, transforms them into mechanical vibrations in the eardrum, and eventually transmits the vibrations to the middle ear, which is similar with acoustic transducers such as microphones. In this research, new approach inspired by the human auditory system is explored to address the challenging difficulties for developing advanced acoustic transducers. In addition, a frequency response function analysis is performed to validate the inverse anti-resonance vibrating structure inspired by human middle ear including ear-drum.
This paper provides a preliminary study on the piezoresistive effect of a styrene-butadiene Rubber (SBR), one of the
main ingredients of automotive tire, dispersed with carbon nanotubes (CNTs) to explore its feasibility as a force sensor
embedded in automotive tires. Typically, the application of CNTs has been successfully applied to the mechanical
sensing technology such as a stress/strain and impact sensor. In this study, the potential of using the SBR/CNT as a force
sensor for monitoring automotive tire deformation is evaluated for the first time. Experimental results show that the
electrical resistance of the SBR/CNT composite changes in response to the sinusoidal loading, as well as static
compressive load. These piezoresistive responses of the SBR/CNT composite will be used for sensing the tire
deformation caused by the vehicle loading or cracks of tires.
This paper presents a preliminary study investigating the development of a new type of non-contacting torque sensor based on the mechanoluminescence (ML) of a microparticles, such as ZnS:Cu. Typically, applications of ML microparticles have been used in a stress sensor applications successfully, in which these particles are applied to realtime visualization of the stress distribution of cracks, impacts, and ML light generation. Kim et al. demonstrated their potentials of ML microparticles by successfully measuring the sinusoidal torque applied to a rotational shaft through the measurement of the ML intensity signature using a photomultiplier tube (PMT) sensor, which can be widely used in various industrial areas such as automotives, robotics, rotors, and turbines. To show their further potential applications, a cost-effective luminescence sensor and UV LEDs are integrated, and used for detecting the variation of ML intensity in this study. In addition, precision sinusoidal torque waveform with high frequency up to 15 Hz is used to investigate the frequency-dependent hysteresis phenomenon.
A new damage detection technique is presented which can localize a breathing crack in a metallic rod-like structure.
Biologically inspired by the combination tone phenomenon which occurs in the human auditory system, the nonlinear
signal produced at the difference combination frequency of the two harmonic excitation frequencies ( f1 - f2 ) is used to
detect and localize the breathing crack. An experimental investigation is performed to verify the proposed approach.
Compared to previously introduced techniques for detection of breathing cracks based on super-harmonic or subharmonic
nonlinear response signals, the proposed approach is much more robust and easier to implement.
Recently, a new biological-inspired fluidic flexible matrix composite (in short, F2MC) concept has been developed for
linear/torsional actuation and structural stiffness tailoring. Although the actuation and the variable stiffness features of
the F2MC have been successfully demonstrated individually, their combined functions and full potentials were not yet manifested. In addition, the current hydraulic pressurization systems are bulky and heavy, limiting the potential of the
F2MC actuator. To address these issues, we synthesize a new variable stiffness actuator concept that can provide both
effective actuation and tunable stiffness (dual-mode), incorporating the F2MC with a compact piezoelectric-hydraulic
pump (in short, PHP). This dual-mode mechanism will significantly enhance the potential of the F2MC adaptive structures.
In recent years, researchers have investigated the feasibility of utilizing piezoelectric-hydraulic pump based
actuation systems for automotive transmission controls. This new concept could eventually reduce the complexity,
weight, and fuel consumption of the current transmissions. In this research, we focus on how to utilize this new
approach on the shift control of automatic transmissions (AT), which generally requires pressure profiling for
friction elements during the operation. To illustrate the concept, we will consider the 1→ 2 up shift control using
band brake friction elements. In order to perform the actuation force tracking for AT shift control, nonlinear force
feedback control laws are designed based on the sliding mode theory for the given nonlinear system. This paper will
describe the modeling of the band brake actuation system, the design of the nonlinear force feedback controller, and
simulation and experimental results for demonstration of the new concept.
KEYWORDS: Actuators, Control systems, Ferroelectric materials, Prototyping, Transducers, Amplifiers, Head, Systems modeling, Servomechanisms, Data modeling
The actuation system of friction elements (such as band brakes) is essential for high quality operations in modern
automotive automatic transmissions (in short, ATs). The current band brake actuation system consists of several
hydraulic components, including the oil pump, the regulating valve and the control valves. In general, it has been
recognized that the current AT band brake actuation system has many limitations. For example, the oil pump and
valve body are relatively heavy and complex. Also, the oil pumps induce inherently large drag torque, which affects
fuel economy. This research is to overcome these problems of the current system by exploring the utilization of a
hybrid type piezo-hydraulic pump device for AT band brake control. This new actuating system integrates a piezo-hydraulic
pump to the input of the band brake. Compared with the current systems, this new actuator features much
simpler structure, smaller size, and lower weight. This paper describes the development, design and fabrication of
the new stand-alone prototype actuator for AT band brake control. An analytical model is developed and validated
using experimental data. Performance tests on the hardware and system simulations utilizing the validated model
are performed to characterize the new prototype actuator. It is predicted that with increasing of accumulator
pressure and driving frequency, the proposed prototype actuating system will satisfy the band brake requirement for
AT shift control.
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