The goal of this research is to develop a localization system for a mobile fastening robot using a camera and ultrasonic sensors. Localization is performed by using triangulation methods on three target fastener heads. Camera calibration parameters are determined and used to obtain a corrected image on which a Circular Hough Transform algorithm is used to determine the location of the three target fastener heads relative to the camera. The distance to the fastener heads is determined using readings from two ultrasonic sensors. A Kalman Filter is developed and used to reduce the noise of the ultrasonic sensor readings. In addition to filtering, calibration techniques are used to correct the readings of the final localization system. Testing of the complete system is done using a coordinate measuring machine.