Passive visual sensor based on weld automatic tracking of welding robot

The invention discloses a passive visual sensor based on the weld automatic tracking of a welding robot. The passive visual sensor comprises a mounting bracket, a system shell, a camera, a dimming and filtering system, a light reflection system and a wire feed adjustment mechanism, wherein the camera and the dimming and filtering system are coaxially arranged on an inner wall of the system shell in the welding process and transmit weld image information in the welding process; the dimming and filtering system is driven through a motor transmission system in the non-welding process and realizes guide and standardization before welding; the light reflection system is arranged on the inner wall of the system shell, is connected with the dimming and filtering system and acquires a welding image; the mounting bracket is arranged on a sixth shaft of the robot; and the wire feed adjustment mechanism is fixedly arranged on a welding gun. The passive visual sensor can be applied to the aspects of information acquisition and identification, weld searching and tracking, penetration control and the like in the welding.