MEMS Accelerometer Sensor Research Articles

MEMS Accelerometer and Hall Sensor based Identification of Electrical and Mechanical Defects in Induction Motors and Driven Systems

MEMS Accelerometer and Hall Sensor based Identification of Electrical and Mechanical Defects in Induction Motors and Driven Systems

MEMS capacitive accelerometer: A review

Micro-electro-mechanical systems sensors are integrated systems used in many fields such as consumer electronics, the automobile industry, and biomedical, and their dimensions change between micrometers and millimeters. MEMS capacitive accelerometers are the most widely used sensor type among MEMS accelerometer sensors. As a result of the external force applied to the capacitive accelerometer sensor, the proof mass inside the sensor moves, and the capacitive change is measured as an electrical signal using reading circuits. In this review paper, general information about MEMS sensors is given, and a comprehensive review is made of MEMS capacitive accelerometers. In the study, the dynamic circuit of the MEMS capacitive accelerometer is given, and the calculation of the important values for the mechanical and electronic structure during the design of the capacitive MEMS accelerometer is explained. In addition, information about the readout circuits used to convert the capacitive change to voltage is given. Finally, the fabrication processes used to produce the final product are explained, and the studies on sample fabrication processes found in the literature are mentioned.

Research and Development of MEMS Accelerometer's Sensor

Currently, MEMS accelerometers are one of the most promising areas in the inertial sensor industry. The design and study of MEMS accelerometers structures is associated with solving problems of mathematical physics. Also, a very important task is to comply with the technological route, including carrying out such operations as deep etching of silicon. This article describes the modeling of the developed geometric model of the sensitive element MEMS accelerometer. The calculations were carried out, which showed that the developed structure is efficient. As a result of the study of the Bosch process using methods for planning multifactor experiments, the modes of deep etching of silicon were optimized. Prototypes of sensitive element MEMS accelerometers have been produced.

Calibration Analysis of High-G MEMS Accelerometer Sensor Based on Wavelet and Wavelet Packet Denoising.

High-G accelerometers are mainly used for motion measurement in some special fields, such as projectile penetration and aerospace equipment. This paper mainly explores the wavelet threshold denoising and wavelet packet threshold denoising in wavelet analysis, which is more suitable for high-G piezoresistive accelerometers. In this paper, adaptive decomposition and Shannon entropy criterion are used to find the optimal decomposition layer and optimal tree. Both methods use the Stein unbiased likelihood estimation method for soft threshold denoising. Through numerical simulation and Machete hammer test, the wavelet threshold denoising is more suitable for the dynamic calibration of a high-G accelerometer. The wavelet packet threshold denoising is more suitable for the parameter extraction of the oscillation phase.

A Novel All-Optical Sensor Design Based on a Tunable Resonant Nanocavity in Photonic Crystal Microstructure Applicable in MEMS Accelerometers

In view of the large scientific and technical interest in the MEMS accelerometer sensor and the limitations of capacitive, resistive piezo, and piezoelectric methods, we focus on the measurement of the seismic mass displacement using a novel design of the all-optical sensor (AOS). The proposed AOS consists of two waveguides and a ring resonator in a two-dimensional rod-based photonic crystal (PhC) microstructure, and a holder which connects the central rod of a nanocavity to a proof mass. The photonic band structure of the AOS is calculated with the plane-wave expansion approach for TE and TM polarization modes, and the light wave propagation inside the sensor is analyzed by solving Maxwell’s equations using the finite-difference time-domain method. The results of our simulations demonstrate that the fundamental PhC has a free spectral range of about 730 nm covering the optical communication wavelength-bands. Simulations also show that the AOS has the resonant peak of 0.8 at 1.644µm, quality factor of 3288, full width at half maximum of 0.5nm, and figure of merit of 0.97. Furthermore, for the maximum 200nm nanocavity displacements in the x- or y-direction, the resonant wavelengths shift to 1.618µm and 1.547µm, respectively. We also calculate all characteristics of the nanocavity displacement in positive and negative directions of the x-axis and y-axis. The small area of 104.35 µm2 and short propagation time of the AOS make it an interesting sensor for various applications, especially in the vehicle navigation systems and aviation safety tools.

Development of a wireless accelerometer-based Intravaginal device to detect pelvic floor motion for evaluation of pelvic floor dysfunction

Urinary incontinence (UI) is experienced by an estimated 51% of women in the U.S. and often results from impaired function or weakening of the pelvic floor muscles. Pelvic floor muscle training (PFMT) is a frontline nonsurgical treatment, yet a number of symptomatic individuals cannot accurately perform a pelvic floor muscle contraction with simple verbal or written instruction. Long-term adherence to PFMT regimens is often a barrier to resolution of symptoms. Various biofeedback tools have been utilized to aid correct pelvic floor muscle performance and adherence. One novel device, the leva® Pelvic Digital Health System, utilizes an intravaginal probe embedded with MEMS accelerometer sensors that allow real-time visualization of the shape and motion of the vagina during PFMT. Early positive results with this device prompted design of a wearable version. The purpose of this study was to design a wearable, wireless clinical research device to optimize MEMS accelerometer sensor placement to detect maximal movement during a pelvic floor muscle exercise (PFME) and to test the form factor for retention and user acceptability. The device comprised a ring designed to sit at the fornix with an extension following the length of the vagina. This paper presents design components and results from clinical testing of 10 subjects. It was determined that a ring form factor alone, similar to other vaginal rings (pessaries, estrogen rings) provided less accurate visual information about PFME performance. By contrast, we determined that a ring with an extension allowed for device retention and improved real-time detection of vaginal shape and motion during PFMT.

Development of seismic acquisition instrumentation system based MEMS accelerometer using SPI communication with Raspberry Pi

The background of this research concerned to the operational cost and human resources to conduct seismic data surveys. In seismic surveys, the tools and cables are very heavy and need very long cables, so they spend a lot of cost and resources. Based on those reasons, an improvement of Geophone technology for data acquisition was needed in this study to reduce cost and resources. Accelerometer based on MEMS technology was proposed to replace a conventional geophone to reduce costs and human resources. In previous research, a study of seismic signal acquisition instrumentation based on MEMS accelerometer sensor could acquire only two geophones. In this study has renewed seismic signal accelerometer by communication aspect to acquire more geophones or seismic signal acquisition instrumentation. So, it would be more efficient and reduce cost and need fewer resources. The hypothesis is Output data of this system is almost the same with output from conventional geophone. This system uses SPI Extender module to make one Raspberry Pi to acquire more MEMS geophone and with further cable reach. Respond result or output of geophone is saved into Raspberry Pi first so that it can be taken wirelessly by the host computer. Trial test is done at Universitas Indonesia. Based on the test results, the response of the MEMS Geophone, when given a wave explosion, is almost the same as a conventional Geophone.

Online vibration monitoring system for rotating machinery based on 3-axis MEMS accelerometer

This article discusses the design of a rotating machine vibration monitoring system in real time by utilizing a 3-axis accelerometer MEMS sensor. The system consists of 2 main parts, namely, vibration data acquisition system and data analyse system with the principle of wireless data communication. The results of vibration measurements from each three MEMS accelerometer sensors will be forwarded by the Arduino Nano microcontroller to the data collection device, the Arduino Uno microcontroller. Also, the machine rotating speed data acquired by the TCRT5000 speed sensor will be forwarded by the Arduino Pro Mini microcontroller to the same collection device. Data that has been recorded by the collection device is then transmitted to the computer through wireless communication using the Node-MCU device. The Lab View software is used as a machine vibration data display that has previously been processed by the computer in accordance with parameters desired by the user. Testing stability of data transmission with a certain length of time and communication distance is carried out to ensure the measurement results are in accordance with the real-time vibration conditions. Test results show an average delay time of below 200ms for the farthest distance from the wireless device signal range.

Developing of the smart quadcopter with improved flight dynamics and stability

The cause of the rapid growth and enhancement in the dynamics of unmanned aerial vehicles (UAVs) is due to its vast utilization in every-day application. The major advantage of UAVs is no risk of human life with secure and suitable surveillance. The UAV facilitates in live video streaming and wide aerial coverage for monitoring. In this project, a type of UAV named quadcopter has been developed. The work mainly consists of design of the quadcopter frame, interfacing of the brushless DC motors and bluetooth module with the microcontroller, and adjustment of the roll, pitch, and yaw for keeping the smooth flight dynamics by flight controller board containing MEMS sensors, i.e., gyroscope, accelerometer, magnetometer, and pressure sensors. The repeated simulation and testing has been carried out in MATLAB for the mathematical modeling of the dynamics of the system, i.e., Euler method for solving differential equation for finding system states, computation of the rotation matrix R and functions to convert from an angular velocity vector w to the derivatives of roll, pitch, and yaw. The improvement in the parameters of the flight dynamics and removing the errors to gain stability in the frame are the main core issues which have been achieved by the several iterations. A closed-loop control system, i.e., PID controller, has been simulated and carefully designed for stabilizing the actual angle from the sensors and desired angle from the pilot. The reduced error rate of 0.05 degrees after every 10 s was achieved.

Selection and Evolution of MEMS Accelerometer Sensor for Measurement of Blast-Induced Peak Particle Velocity

An ambiguous ground vibration caused by blasting operation is undesirable and results in grievous damage to surrounding structures, residential premises, and other sensitive sites. Consequently, proper monitoring of ambiguous ground vibration is an indispensable prerequisite to pinpoint the safe limits in and around mines to reduce their hazardous effects. The recently proliferated microelectro-mechanical-system (MEMS) based accelerometer sensors are becoming widely prevalent in vibration and condition monitoring applications. In this article, a three-axis, low- g , high-accuracy, inexpensive MEMS accelerometer has been selected and evaluated to measure blast-induced ground vibration. In addition, a global system for a mobile SIM 800 device is used as a radio frequency module and integrated to design an effective test setup. The experiment has been carried out by installing test setup at Mine-A, and the obtained results ensure that the peak particle velocity ranges from 0.19 to 8.60 mms at different monitoring locations.

HTCC APPROACH FOR PACKAGING MEMS ACCELEROMETER SENSORS AND ASSOCIATED ROIC.

18Jul 2018 HTCC APPROACH FOR PACKAGING MEMS ACCELEROMETER SENSORS AND ASSOCIATED ROIC. K. S. R. C. Murthy. Accurex Solutions (P) Ltd., # 782, 3rd Main, 1st Cross, BEML Layout, 5th Stage, Rajarajeswari Nagar, Bangalore 560 098, India.

Implementasi Integral Fourier untuk Mendapatkan Sinyal Kecepatan dan Sinyal Simpangan dari Data Digital Sensor MEMS Accelerometer

This paper discusses and implements a simple technique to obtain the velocity and the displacement signals from the digital data of the MEMS accelerometer sensor, which is an acceleration signal. The method used is a numerical integral, i.e. discrete Fourier integral. Technically, the digital signal data from the MEMS accelerometer sensor is converted from time domain to frequency domain by using Discrete Fourier Transform (DFT). In the frequency domain, the acceleration signal component is integrated once to obtain its velocity components, and is integrated twice to obtain its displacement component. Furthermore, Invers Discrete Fourier Transform (IDFT) is performed to obtain the form of velocity and displacement signals in time domain. The application of these theories and methods gives quite good results, especially for low frequency signals recorded at high sampling rates.

Implementasi Integral Fourier untuk Mendapatkan Sinyal Kecepatan dan Sinyal Simpangan dari Data Digital Sensor MEMS Accelerometer

Implementasi Integral Fourier untuk Mendapatkan Sinyal Kecepatan dan Sinyal Simpangan dari Data Digital Sensor MEMS Accelerometer

Modeling and Analysis of a Closed-Loop System for High-Q MEMS Accelerometer Sensor

High-Q sensing element is desirable for high performance while makes the loop control a great challenge. This paper presents a closed-loop system for high-Q capacitive MEMS accelerometer which has achieved loop control effectively. The proportional-derivative(PD)control is developed in the system to improve the system stability. In addition, pulse width modulation (PWM) electrostatic force feedback is designed in the loop to overcome the nonlinearity. Furthermore, a sigma-delta (ΣΔ) modulator with noise shaping is built to realize digital output. System model is built in Matlab/Simulink. The simulation results indicate that equivalent Q value is reduced to 1.5 to ensure stability and responsiveness of the system. The effective number of bits of system output is 14.7 bits. The system nonlinearity is less than 5‰. The equivalent linear model including main noise factors is built, and then a complete theory of noise and linearity analysis is established to contribute to common MEMS accelerometer research.

Wearable Healthcare Device For Pregnant Women

Human resource is the backbone of developing and under developed nations. In developing nations like India, rural areas are more when compared to the cities. People in rural areas are not really concerned about their health, because of unavailability of hospitals in the nearby areas and also they need to travel long distance even for small injuries and routine checkups. Pregnant women from rural areas don’t do their regular checkups at the early stage of pregnancy. The mobile application can access this information and can check for emergency condition.. The project aim is to design a connected wearable healthcare device to monitor pregnant women health status continuously and provide timely alert as they go about their everyday lives. The device has sensors built into it to provide vital health data of the mother in the later stages of pregnancy. While detecting an abnormal event the device issues alert to the family members and doctors by communicating with a custom smartphone app over internet and can also send e-mail to them. An emergency button helps the mother to call for help.The device monitors the mother’s physical activity, sleeps quality, heart activity and infrared body temperature helping the doctor to analyze the condition. Heart rate is measured by an optical heart rate sensor circuitry. Respiration rate sensor enables to measure the breathing rate by detecting changes in temperature when the patient breathes in and out. A 3-axis MEMS accelerometer sensor helps to know the daily body activity of the monitored women.

Denoising MEMS accelerometer sensors based on L2‐norm total variation algorithm

A method for denoising accelerometer data based on the L2-norm total variation (LTV) algorithm is presented. In order to collect accelerometer data, a wireless accelerometer sensor was developed that is directly connected to a central node. By benefiting from the LTV algorithm, the obtained signals from the accelerometer are denoised. The proposed method is tested by denoising in different accelerometer signals and the results are evaluated by signal-to-noise ratio and power spectral density functions of the signals. The obtained results reveal that noise reduction has been implemented satisfactorily. Hence, the measurement accuracy of accelerometer signals for the proposed method have improved ~4-10% than other the three low-pass filters including Savitzky-Golay, equiripple-pass-band and Butterworth.

Gyroscope-reduced inertial navigation system for flight vehicle motion estimation

In this paper, a novel configuration of strategically distributed accelerometer sensors with the aid of one gyro to infer a flight vehicle’s angular motion is presented. The MEMS accelerometer and gyro sensors are integrated to form a gyroscope-reduced inertial measurement unit (GR-IMU). The motivation for gyro aided accelerometers array is to have direct measurements of angular rates, which is an improvement to the traditional gyroscope-free inertial system that employs only direct measurements of specific force. Some technical issues regarding error calibration in accelerometers and gyro in GR-IMU are put forward. The GR-IMU based inertial navigation system can be used to find a complete attitude solution for flight vehicle motion estimation. Results of numerical simulation are given to illustrate the effectiveness of the proposed configuration. The gyroscope-reduced inertial navigation system based on distributed accelerometer sensors can be developed into a cost effective solution for a fast reaction, MEMS based motion capture system. Future work will include the aid from external navigation references (e.g. GPS) to improve long time mission performance.

Feasibility Study of Community Earthquake Warning System Proposed for Mbeya City and Surrounding Regions

The Mbeya city and its surrounding regions (Rukwa, Katavi and Njombe) in south western Tanzania, fall among the fast growing economical regions in Tanzania. It is also unfortunately under potential for seismic risk due to its proximity to the western and eastern junction of the East African Rift (EAR) Valley. Construction of Community Earthquake Early Warning (CEEW) system model based on community owned MEMS accelerometer sensors in being proposed for the region. To optimize the warning time function and as the process of planning and designing the community hosted seismic network, the paper presents the simulation of warning times that can be realized in this region based on the distribution of sensor stations in relation to the historical strong earthquakes and target sites. The distribution of sensor stations determines the detection and reporting time of the event, while location of earthquakes and position of target site determine the available warning time for the target to be protected. Testing the various sensor station configura- tions (regional, On-site and Hybrid) models of CEEWS by simulation of scenario earthquakes, the hybrid configuration that distributes sensor stations closer to the source and on target sites, was able to provide at least 5 seconds of warning times to various targets. This time has been demon- strated to be enough for shutting down hazardous industrial processes and for people to take cover at safer locations to reduce injuries.

The Design of New Low Cost Ocean Bottom Seismometers

The performance of the Ocean Bottom Seismometers (OBS) in seismic wave field measurement is vital to seismic exploration. In order to improve the performance of OBS, we have been developed a new Ocean Bottom Seismometer based 3-component MEMS accelerometer sensors. In order to sample seismic data synchronously, we have been designed multichannel A/D unit under the control of MSP430.We also are involved in a handle and sophisticated equipment allows to storage sampling data in the SD card module. The system based MEMS sensor are compared with conventional analog moving coil geophones, the result shows that the new measurement system with the advantage of high dynamic range, low noise and anti-jamming that suit for the high resolution seismicity information. The paper show that the new digital OBS using MEMS accelerometer will replace the tradition OBS in oil exploration, scientific research and seabed surveys.

Analog Component Development for 300°C Sensor Interface Applications

The development of Enhanced Geothermal Systems (EGS) for base-load electrical power generation will require electronics for sensing and control during exploration and drilling and also during production. The operating temperature environments for these applications will generally be more extreme than those encountered by electronics currently deployed for oil and gas development and production monitoring. To address this requirement, electronic components have been designed and fabricated for operation at temperatures of 300°C. These integrated circuits use silicon-on-insulator (SOI) fabrication processes to achieve high temperature operation. High-fidelity simulation models have been developed by characterization of SOI devices at 300°C. These device models were employed to design components required for the development of a down-hole orientation module. A wide-bandwidth, low-noise operational amplifier has been developed for use with MEMS accelerometer sensors. A multi-channel synchronous voltage-to-frequency converter with built-in reference and oscillators has also been developed for use with 3-axis flux-gate magnetometers. The components themselves are general purpose and could easily be used for other high-temperature sensor-interface applications. .