Cylinder diameter measurement with iPhone embedded LiDAR and RGB sensors

Abstract

This paper presents a novel method for measuring the size of standard cylinders with the LiDAR and RGB sensors embedded with iPhones. First, we reconstruct 3D points of cylindrical surfaces using the LiDAR data. With 3D point cloud data, we fit the orientation of the cylinder with center pixels. Since the LiDAR does not offer 3D points with high resolution nor high accuracy, we select a segment of the point cloud data and compute the average depth of these segment pixels as the distance from the cylinder to the camera. We then compute the diameter by the geometric relationship of each point on the cylinder. Finally, we improve the measurement accuracy by applying a estimation function. Experimental results show that at distances from 0.3 m to 2 m with different tilt angles, the proposed method can achieve 3 cm cylinder diameter measurement accuracy for the cylinders with a diameter of 8 cm and 14 cm, and 5 cm accuracy for the cylinder with a diameter of 22 cm.