Development of Position Measurement System for Construction Pile Using Laser Range Finder

This paper describes the development of an accurate long-distance position measurement system for construction pile using Laser Range Finders (LRF). The pile positioning and driving is the first work that is one of the important works to request the attentions in the building construction. In general, though the position of piling is measured by the total station that is high accurate survey machine by two workers, it has been often generated to measure the wrong points by mistake. In order to suppress such misunderstanding measurement, low-cost and simple position measurement system by LRF was developed. The LRF is a laser sensor that can measure the distance of a target object, an obtained data from the LRF are nothing more than the contours of objects. Therefore, as the survey target, we adopted the cylindrical shape object that was invariant against rotation and similar to the pile shape and the center position of the circular arc was analyzed by applying the least square method and maximum likelihood estimation. The error between the analysis and the measurement was corresponds enough to the allowable accurate range. Applying this measurement system to the construction pile work as a confirmation inspection, the exact pile positioning and real-time pile navigating and driving was achieved by only a worker, the high efficient and short term works were surely performed.