Exemplary embodiments provide a resistance welding method capable of stabilizing quality or improving efficiency of resistance welding such as spot welding. The system includes a clearance sensor to output a clearance measurement signal. A stiffener is mounted to the back of the flexible circuit substrate to support wire bonding of the image capture device onto the flexible circuit substrate andor to support the mounting of additional components. The railcar-moving vehicle is capable of extended operation at highway speeds both on and off rails.