This paper describes a study of high accuracy and low cost position measurement system using Laser Range Finder (LRF), and its application for construction pile work. Since the LRF is a sensor which can measure distance to surfaces of objects by radiating laser beams from itself and receiving the reflected ones, an obtained data from the LRF are nothing more than the contours of objects. In proposed system, the obtained data from LRF assumed the arc-shaped contours of the bar, the center position was analyzed introducing the least square method and maximum likelihood estimation. The error between the analysis and the measurement corresponds enough to the allowable accurate range. Additionally, improving the angular resolution of the LRF by using a pan unit, the highest accurate center position was able to be acquired. Applying this system to the construction work, the high accurate pile marking and the pile drive positioning were recognized. Since this measurement was achieved by only a worker and the position and direction of the worker was easily found, the high efficient and short term works were surely performed.
Gait Measurement System for the Multi-Target Stepping Task Using a Laser Range Sensor