4D modeling of soil surface during excavation using a solid state 2D profilometer mounted on the arm of an excavator
Abstract The aim of this research is to create a 4D point cloud map from a trench through a solid state 2D profilometer. The profilometer is integrated with an 8.5 ton medium size excavator's machine control system with pose calculation. Accordingly, the point cloud was transformed to a work coordinate system. We used a recently developed pulsed time of flight laser light detection and ranging profilometer, which makes possible simultaneous depth measurements to 256 directions in an angle range of 20deg and measurement range from 1 m to 8 m with a frame rate of 25 frames per second under sunlight conditions (50 Klux) The analysis is based on a 4D map, which consists of 3D data (XYZ) and intensity information. The XYZ coordinates give the position of an object, and the intensity data can be used to roughly identify materials and recognise surface markings, such as texts. An analysis of the results shows that the detection accuracy of the profilometer is better than 10 mm. The main advantages of our method are accuracy, high update rate, compact size, real time measurement and a construction without moving parts. Our technique has a great potential in construction applications, where accurate measurements of a surface shape are needed.