PURPOSES : The purpose of this study is to identify the dynamic behavior of a cement concrete paving machine (paver) by measuring its response using accelerometers. This is because the dynamic behavior of pavers affects the quality of data from various applications of IoT sensors, such as laser, ultrasonic, optical sensors and so on. Therefore, it is believed that the understanding of dynamic behaviors can contribute to the effective use of various IoT sensors for the acquisition of real-time quality control data in pavement construction.
METHODS : Dynamic signals are obtained using accelerometer sensors to identify the dynamic characteristics of paving machines. The main parameters for acquiring dynamic signals are the status of the machine’s operating or standby conditions, and available locations for attaching various IoT sensors. Time domain data are logged at a particular sampling speed using a low-pass filter, subsequently, they are converted to digital data, which are analyzed on three rectangular axes. In addition frequency analysis is conducted on the measured data for identifying the peak frequencies, via FFT (Fast-Fourier-Transform) using MATLAB.
RESULTS : The magnitude of the x-directional vibration is higher than that of any other direction under the paver’s operating or standby condition. However, signals from the smoother beam show that the z-directional vibration is more significant in the operating status. It means that the primary vibration depends on the location. Furthermore, the peak frequencies are quite various depending on the status of a paver and its sensing location.
CONCLUSIONS : The magnitude of machine vibration and peak frequencies at each status or location are identified from time- and frequency-domain data. When using IoT sensors for quality control or monitoring pavements in construction, the dynamic characteristics of a paver should be considered to mitigate the interference of signals from the paver body or its elements.

ABSTRACT
1. 서론
2. 연구배경
    2.1. 연구동향
    2.2. 품질관리를 위한 센서 설치
    2.3. 콘크리트 포장의 시공 장비
3. 동적 신호의 획득
    3.1. 가속도계의 설치
    3.2. 가속도계의 신호 측정
    3.3. 가속도계 신호의 주파수 분석
4. 동적 신호의 분석
    4.1. 시간 영역의 진동 분석
    4.2. 주파수 영역의 진동 분석
5. 결론
REFERENCES

• 한승환(도로교통연구원) | Han Seung-Hwan (Korea Expressway Corporation Research Institute) 교신저자