Survey of Depth Cameras for Process-integrated State Detection in Logistics

Highly efficient transport and storage are key aspects of logistics, and the increasing pace of digitalization means that more and more options are being used to address these challenges. One important aspect of this is depth sensors for precise state detection. They allow a more closely meshed monitoring of logistics operands. However, the depth sensor market is highly complex and dynamic. New technologies arise and the old one are developed further or disappear from the market. Therefore, we have created an overview in which we present and categorize the different technologies currently available on the market. We show the working principles and briefly describe the use and why experts knowledge is still a key factor. In particular, we will focus on the different types of sensors, active and passive stereo vision, structured light and time-of-flight. These have a central role since the function directly allows conclusions to be drawn on the error behavior in general and for the various logistics objects in particular. We focus on depth cameras, that are set apart from depth scanner in that they capture an instant depth image, which enables process integrated measurements, even of free-moving objects.