|Visual Precise Measurement of Pile Rebound and Penetration Movement Using a High-Speed Line-Scan Camera
Mee-Seub Lim/Bum-Jae You/Sang-Rok Oh/Song-Soo Han/Sang Hun-Lee
Transaction on Control Automation, and Systems Engineering, vol. 4, no. 4, pp.314-346, 2002
Abstract : When a construction company builds a high structure, many piles should be driven into the ground by a hammer whose weight is 7,000 Kg in order to make the ground under the structure safe and strong. So, it is essential to determine whether a pile is penetrated into the ground enough to support the weight of the structure since ground characteristics at different locations are different each other. This paper proposes a visual measurement system for pile rebound and penetration movement including vibration using a high-speed line-scan camera and a specially designed mark to recognize two-dimensional motion parameters of the mark using only a line-scan camera. A mark stacking white and black right-angled triangles is used for the measurement, and movement information for vertical distance, horizontal distance and rotational angle is determined simultaneously. Especially, by adopting a line-scan CCD camera whose line rate is 20 KHz, the measurement performance of dynamic characteristics of the pile at impact instant is improved dramatically.
Keyword : visual measurement, line-scan camera, pile movement, image processing