The invention relates to a mobile radiation image capturing system comprising : an X-ray radiation generation unit mounted on a mobile carriage a drive unit configured to move the carriage over the floor by linear motion in two dimensions and/or by rotation at least one radiation image detection unit at least one sensor unit (10, 11) configured to determine an orientation and/or a position of the radiation generation unit and the detection unit relative to each other, a processing unit (30) configured to determine whether the radiation generation unit and the detection unit have a predetermined orientation and/or position relative to each other and, in the negative, how the carriage and/or the radiation generation unit has to be moved, and to control an output unit (31) to output the determined positioning information and/or to control the drive unit (33) to move the carriage.
