• 제어로봇시스템학회논문지
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• 제16권5호
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• pp.440-445
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• 2010

This paper proposes a single accelerometer sensor control algorithm to mobile inverted pendulum, generally called 'Segway', and evaluates the performance of this system comparing to the conventional ones. The commercialized 'Prototype Segway-PT' is initially considered as a next-generation transport vehicle. However, this robot is operated by three gyroscopes and two accelerometers to control the posture and speed, and it requires the complex signal processing for fusing the two sets of data. As the result of this, the growth rate of market size of 'Segway' is slow because of its high price mainly. In this paper, the mobile inverted pendulum is operated by a single accelerometer to simplify the control system to lower the price. Low pass filter is one of the good sensors to reducing the variation of an accelerometer, but it has time delay. This time delay disturbs real-time mobile inverted pendulum control. Like this, other various algorithms are used for this system, but each one has its own weak point. So this paper proposes a new filtering method, median filter and EKF. Median filter is used to image processing to reject impulse elements like salt and pepper noise. As the major performance evaluation parameter for the accelerometer, the high-frequency to low frequency ratio from FFT (Fast Fourier Transform) is used. Effectiveness of the proposed algorithms has been verified through the real experiments and the results are demonstrated.

• 한국정보통신학회논문지
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• 제21권2호
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• pp.285-293
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• 2017

줄넘기는 줄을 돌리는 손동작과 뛰어오르는 동작이 결합된 운동으로 정확한 카운트를 위해서는 두 동작을 함께 고려해야 한다. 이전의 연구들에서는 단순 반복적인 운동인 윗몸일으키기, 팔굽혀펴기, 아령 운동과 함께 치부하여 하나의 동작만을 체크하여 카운트 하였다. 이것은 실제 줄넘기 동작과는 차이가 있으며 두 동작 중 하나의 동작만을 하고 있다면 확인해내지 못하는 문제가 있다. 본 논문에서는 6축 가속도 자이로 센서를 이용하여 두 동작을 모두 확인하고 카운트하는 방법을 제안한다. 가속도 센서를 이용하여 뛰어오르는 동작을 확인하며 자이로 센서를 이용하여 손동작을 확인한다. 이때 확인되는 값의 파형을 이용하여 줄넘기 횟수를 카운트하게 된다. 제안하는 방법은 실제 실험을 통하여 카운트 방법의 성능을 확인할 수 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권1호
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• pp.318-330
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• 2015

In wearable sensor systems (WSSs), sensor nodes are deployed around human body parts such as the arms, the legs, the stomach, and the back. These sensors have limited lifetimes because they are battery-operated. Thus, transmission power control (TPC) is needed to save the energy of sensor nodes. The TPC should control the transmission power level (TPL) of sensor nodes based on current channel conditions. However, previous TPC algorithms did not precisely estimate the channel conditions. Therefore, we propose a new TPC algorithm that uses an accelerometer to directly measure the current channel condition. Based on the directly measured channel condition, the proposed algorithm adaptively adjusts the transmission interval of control packets for updating TPL. The proposed algorithm is efficient because the power consumption of the accelerometer is much lower than that of control packet transmissions. To evaluate the effectiveness of our approach, we implemented the proposed algorithm in real sensor devices and compared its performance against diverse TPC algorithms. Through the experimental results, we proved that the proposed TPC algorithm outperformed other TPC algorithms in all channel environments.

• International Journal of Advanced Culture Technology
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• 제5권2호
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• pp.54-62
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• 2017

Currently, falling to industrial field workers is causing serious injuries. Therefore, many researchers are actively studying the fall by using acceleration sensor, gyro sensor, pressure sensor and image information.Also, as the spread of smartphones becomes common, techniques for determining the fall by using an acceleration sensor built in a smartphone are being studied. The proposed method has complexity due to fusion of various sensor data and it is still insufficient to develop practical application. Therefore, in this paper, we use acceleration sensor module built in smartphone to collect acceleration data, propose a simple falling algorithm based on accelerometer sensor data after normalization and preprocessing, and implement an Android based app.

• 전자공학회논문지D
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• 제34D권7호
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• pp.30-36
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• 1997

Bump bonded piezoesistive silicon accelerometer was fabricated by the porous silicon micromachining and th eprocess technique of integrated circuit. The output voltage of the accelerometer fabricated on (111)-oreiented Si substrates with n/n$^{+}$n triple layers showed good linear characteristic of less than 1%. The measured sensitivity and the resonant frequency was about 743 .mu.V/g and 2.04 kHz, respectively. And the transverse sensitivity of 5.2% was measured from the accelerometer. Also, to investigate an influence on the output characteristics of the sensor due to bump bonding, the values of the piezoresistors were measured through thermal-cycling test in the temperature variation form -50 to 120.deg. C. Then, there was 0.014% resistance changes about 3.61 k.ohm., so sthe output charcteristics of the sensor was less affected by bump bonding.g.

• International Journal of Automotive Technology
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• 제6권5호
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• pp.475-481
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• 2005

This paper deals with the algorithm of estimating the longitudinal speed of a braking vehicle using measurements from an accelerometer and a standard wheel speed sensor. We evolve speed estimation algorithms of increasing complexity and accuracy on the basis of experimental tests. A final speed estimation algorithm based on a Kalman filtering is developed to reduce measurement noise of the wheel speed sensor, error of the tire radius, and accelerometer bias. This developed algorithm can give peak errors of less than 3 percent even when the accelerometer signal is significantly biased.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2018년도 제58차 하계학술대회논문집 26권2호
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• pp.221-222
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• 2018

본 논문에서는 android의 accelerometer sensor를 활용하여 예기치 못한 상황에 사용자를 보호 할 수 있는 어플리케이션을 설계하고 구현한다. 이 어플리케이션은 스마트폰을 흔들 때 accelerometer sensor가 센싱하여 어플리케이션을 자동으로 실행한다. 또한 경광등 소리를 울리고 사용자의 위치정보를 어플리케이션에 저장된 지인의 연락처로 전송한다. 사용자는 자신이 빈번하게 다니는 경로를 저장할 수 있으며, 이 경로에 대한 정보를 연락처에 저장된 지인들에게 제공한다. 이 어플리케이션을 사용하는 사용자는 범죄로부터 자신을 지키고, 위험한 경우 주변 사람들에게 도움을 요청할 수 있는 기능을 제공한다.

• 드라이브 ㆍ 컨트롤
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• 제13권1호
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• pp.49-53
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• 2016

The accurate calculation of bucket tip position has a large influence on showing the motion of an excavator on the display device of the excavator and controlling the excavator automatically. It is generally known that Inertial Measurement Unit (IMU) sensors are more accurate than accelerometer-based sensors while the boom, arm or bucket moves because additional forces beyond gravity add additional acceleration to the sensors. To prove the accuracy difference between the two types of sensors, a position recognition system using an accelerometer-based sensor and an IMU sensor is implemented on the excavator. The experimental results show that the system using the IMU sensor significantly reduces the position recognition error while bucket moves and additional force beyond gravity exists.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅲ
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• pp.1495-1498
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• 2003

This paper has been studied about designed digital-pen using PIC and Accelerometer and about calculated acceleration by the measure analog signal from accelerometer Finally, we calculate the coordinates and the tilt about the acceleration and discuss the possibility of using the digital-pen from cellular phone. And we discuss about the full-duplex communication of input data that displayed in cellular phone.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 G
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• pp.2504-2508
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• 1998

In this paper, we propose the new detecting method for three dimensional piezoresistive silicon accelerometer. Furthermore the accelerometer is formed to have endurance for high temperature by perfect isolation of the piezoresistors using Silicon On Insulator(SOI) wafer. Sensor size are optimized with analytical formulae and extended with FEM simulation for the more detailed results. The accelerometer was fabricated by bulk micromachining techonology. We measured the temperature characteristics and the output characteristics, and the both characteristics were compared with the simulated results