A method and system are provided for a trackless autonomous crawling all-position arc welding robot with wheels and permanent magnet caterpillar belts. A sensor detects a welding seam position and transmits the position to a tracking controller. The tracking controller sends instructions to a welding torch which may be moved in generally horizontal and vertical directions based upon the instructions. Additionally, a crawler drive controller receives the welding seam position and sends a control signal to an AC servomotor drive that positions the crawler based on the control signal.