Semi-Automatic Registration of a Robotic Total Station and a CAD Model Without Control Points

The accurate registration of a robotic total station with respect to a given CAD model is a crucial task in the construction industry. Common registration techniques rely on a reference network of control points in the CAD model. One must establish correspondences between control points in the CAD model and measured points in the field. Usually physical markers or natural points of interest are selected as control points. We present a user-guided algorithm for simple and efficient registration of a robotic total station with a CAD model in indoor environments without the need for control points. The user interaction is reduced to selecting a local Manhattan-like corner structure for initial model alignment; accurate registration of the device is carried out automatically. Our algorithm relies on angle and distance measurements only and, therefore, is not limited to vision based robotic total stations. In particular, we propose a new algorithm for robust Manhattan corner extraction.