Eight-axis robot space curve welding system and method for recognizing welding line by means of lasers

The invention discloses an eight-axis robot space curve welding system for recognizing a welding line by means of lasers. The system comprises a tilting/rotating two-axis positioner used for fixing a workpiece, a laser sensor, a laser sensor fixing element, a welding gun, a welding gun fixing element and a welding robot. The workpiece is fixed to the tilting/rotating two-axis positioner and does tilting and/or rotating motion along with the tilting/rotating two-axis positioner. The laser sensor is mounted on the laser sensor fixing element. The laser sensor fixing element is clamped on the welding gun. The welding gun is mounted on the welding gun fixing element. The welding gun fixing element is mounted on a flange plate at the tail end of the welding robot. Both the laser sensor and the welding gun can move along with the tail end of the welding robot. The invention further discloses an eight-axis robot space curve welding method for recognizing the welding line by means of the lasers. The problems that existing space curve welding line off-line programming is not high in precision, the teaching workload of space curve welding line teaching programming is large, and efficiency is low are solved. Efficiency and precision are high.