3D Vision Sensing for Grasp Planning: A New, Robust and Affordable Structured Light Approach

In this paper we present a new approach to 3D shape acquisition. This implementation enables a robot arm to move the scan unit over the object without the scan unit being tracked. The chosen structured light approach uses an initially unknown white noise pattern that can easily be projected with any fixed pattern projection system. Object points are acquired on the basis of finding correspondences in the pattern in the camera image of the current scene. This is achieved by using a fast SSD correlation algorithm. In the current test setup we are using a standard video beamer and a standard digital camera, but we have also set up a scan head for fixation on a robots’ wrist. The special requirements of this miniaturized system will be explained as well as our implementation. Our approach reduces hardware complexity to a minimum using only one calibrated camera and one calibrated fixed pattern projector. In this paper we present the whole system also including the calibration procedure. The focus will be on the hardware setup, but we also give an introduction to the software methods used.