• Smart Structures and Systems
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• v.2 no.2
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• pp.115-126
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• 2006

The Terra-Scope system is an affordable 4-D down-hole seismic monitoring system based on independent, microprocessor-controlled sensor Pods. The Pods are nominally 50 mm in diameter, and about 120 mm long. They are expected to cost approximately $6000 each. An internal 16-bit, extremely low power MCU controls all aspects of instrumentation, eight programmable gain amplifiers, and local signal storage. Each Pod measures 3-D acceleration, tilt, azimuth, temperature, and other parametric variables such as pore water pressure and pH. Each Pod communicates over a standard digital bus (RS-485) through a completely web-based GUI interface, and has a power consumption of less than 400 mW. Three-dimensional acceleration is measured by pure digital force-balance MEMS-based accelerometers. These accelerometers have a dynamic range of more than 115 dB and a frequency response from DC to 1000 Hz with a noise floor of less than $30ng_{rms}/{\surd}Hz$. Accelerations above 0.2 g are measured by a second set of MEMS-based accelerometers, giving a full 160 dB dynamic range. This paper describes the system design and the cooperative shared-time scheduler implemented for this project. Restraints accounted for include multiple data streams, integration of multiple free agents, interaction with the asynchronous world, and hardened time stamping of accelerometer data. The prototype of the device is currently undergoing evaluation. The first array will be installed in the spring of 2006.

• Smart Structures and Systems
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• v.6 no.5_6
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• pp.641-659
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• 2010

Structural Health Monitoring (SHM) gradually becomes a technique for ensuring the health and safety of civil infrastructures and is also an important approach for the research of the damage accumulation and disaster evolving characteristics of civil infrastructures. It is attracting prodigious research interests and the active development interests of scientists and engineers because a great number of civil infrastructures are planned and built every year in mainland China. In a SHM system the sheer number of accompanying wires, fiber optic cables, and other physical transmission medium is usually prohibitive, particularly for such structures as offshore platforms and long-span structures. Fortunately, with recent advances in technologies in sensing, wireless communication, and micro electro mechanical systems (MEMS), wireless sensor technique has been developing rapidly and is being used gradually in the SHM of civil engineering structures. In this paper, some recent advances in the research, development, and implementation of wireless sensors for the SHM of civil infrastructures in mainland China, especially in Dalian University of Technology (DUT) and Harbin Institute of Technology (HIT), are introduced. Firstly, a kind of wireless digital acceleration sensors for structural global monitoring is designed and validated in an offshore structure model. Secondly, wireless inclination sensor systems based on Frequency-hopping techniques are developed and applied successfully to swing monitoring of large-scale hook structures. Thirdly, wireless acquisition systems integrating with different sensing materials, such as Polyvinylidene Fluoride(PVDF), strain gauge, piezoresistive stress/strain sensors fabricated by using the nickel powder-filled cement-based composite, are proposed for structural local monitoring, and validating the characteristics of the above materials. Finally, solutions to the key problem of finite energy for wireless sensors networks are discussed, with future works also being introduced, for example, the wireless sensor networks powered by corrosion signal for corrosion monitoring and rapid diagnosis for large structures.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1427-1428
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• 2015

MEMS(Micro Electro-mechanical System) are getting attention as promising industry in the 21st century. Car air bags, acceleration sensors, and medical, information appliances are being actively applied in MEMS. This paper suggest the electrical electrodes of brain signal applied MEMS model and the prototype design for EEG signal amplification circuit. Also, we suggest an independent BCI(Brain Computer Interface) system with brain electrical signal of electrode models and wireless communication platform.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.6
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• pp.1103-1108
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• 2016

The development of a variety of sensor technology, users smart phone, the use of motion recognition apparatus such as a console game machines is increasing. It tends to user needs motion recognition-based input device are increasing. Existing motion recognition mouse is equipped with a modified form of the mouse button on the outside and serves as a wheel mouse left and right buttons. Existing motion recognition mouse is to manufacture a small, there is a difficulty to operate the button. It is to apply the motion recognition technology the motion recognition technology is used only pointing the cursor there is a limit. In this paper, use of MEMS-based motion recognition sensor, the body of the two-point operation data by recognizing the operation of the (thumb and forefinger) and generating a control signal, followed by studies on the generated control signal to a wireless transmitting computer input device.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.439-439
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• 2000

In this paper, the relationship among the vertical acceleration, measuring points and walking patterns is analyzed. To measure acceleration, the acceleration measurement unit and communication board is constructed. It uses MEMS accelerometer ADXL-202 that detects 2-axis acceleration simultaneously. It is shown by the experiment test that the walking pattern is recognized and walking step is detected at easy when acceleration measurement unit is mounted on leg.. This results can be directly utilized in designing the personal navigation system with low-cost inertial sensor.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.2
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• pp.361-366
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• 2017

The abnormal state of the main equipment across the industry is accompanied by abnormal rise of temperature, change in the vibration and noise. In this study, we developed a smart sensing module equipped with BLE, and developed a smart sensing device that can detect abnormal vibration due to its own flaws of the equipment by interfacing with an MEMS-based acceleration sensor. The smart sensing device developed in this study can be easily installed in a small space and can monitor the vibration status of the equipment in real time, and can easily inform the user of the steady state and the problem occurrence status with array LED display.

• Journal of the Korea Convergence Society
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• v.11 no.11
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• pp.47-53
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• 2020

There is a need for a system that provides early warning of presence and type of failure of automobile wheel bearings through the application of predictive fault analysis technologies. In this paper, we presented a sensor module mounted on a wheel bearing and a diagnostic system that collects, stores and analyzes vehicle acceleration information and vibration information from the sensor module. The developed sensor module and predictive analysis system was tested and evaluated thorough excitation test equipment and real automotive vehicle to prove the effectiveness.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.79-79
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• 2000

In this Paper, the PC input device using MEMS gyros and accelerometer is newly developed, so that it can measure rotation rate and linear acceleration of the human body in space. In General, the human motion has 6 degree of freedom but 2 degree of freedom is enough PC monitor with 2D display. Therefore the simple method is proposed to achieve minimum degree of freedom. It is also applied to the PC mouse. This method can be expanded to the input device for internet set-top box or internet TV.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.1
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• pp.26-33
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• 2011

In this study, a high-sensitive smart wireless sensor based on an Imote2 sensor platform is developed for structural health monitoring of harbor structures. To achieve the objective, the following approaches are implemented. Firstly, the smart wireless sensor based on the high-performance Imote2 sensor platform is designed to measure acceleration with high sensitivity from structures. Secondly, embedded software is designed for autonomous structural health monitoring. Finally, the performance of the smart wireless sensor is estimated from experimental tests on a lab-scaled caisson structure.

• Journal of Sensor Science and Technology
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• v.21 no.2
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• pp.114-120
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• 2012

This paper describes the design, fabrication and testing of a micromachined resonant accelerometer consisting of a symmetrical pair of proof masses and double-ended tuning fork(DETF) oscillators. Under the external acceleration along the input axis, the proof mass applies forces to the oscillators, which causes a change in their resonant frequency. This frequency change is measured to indicate the applied acceleration. Pivot anchor and leverage mechanisms are adopted in the accelerometer to generate larger force from a proof mass under certain acceleration, which enables increasing its scale factor. Finite element method analyses have been conducted to design the accelerometer and a silicon on insulator(SOI) wafer with a substrate glass wafer was used for fabricating it. The fabricated accelerometer has a scale factor of 188 Hz/g, which is shown to be in agreement with analysis results.