Operation control system for a scanning galvanometer

Abstract

Abstract An operation control system for a scanning galvanometer associated with an arc sensor (20) of a welding robot for sensing a weld line, and having a swing mirror (23) integral therewith for a laser beam scanning. A memory (43) stores waveform data of a galvanometer drive command current obtained by synthesizing a constant-speed command current and an acceleration/deceleration command current, and an address circuit (42) causes the waveform data to be output from the memory (43) at predetermined intervals. A D/A converter (44) converts the output of the memory (43) to an analog value, and a scanner drive circuit (45) drives the galvanometer (22), which swings the swing mirror (23) to detect the weld line. Accordingly, the scanning galvanometer (22) is driven in accordance with the waveform of the galvanometer drive command current in such a manner that it is driven at a constant angular velocity in swing angle regions other than turning points, and at a constant angular acceleration in the vicinity of the turning points. Therefore, the swing angle is accurately controlled over the entire operating range, and the change of direction of the swing angle at the turning points is effected in a very short time. Further, overshoot does not occur at the turning points of the triangular wave, and as a result, the measurement for detecting the weld line by a laser beam scanning can be effectively executed.

Inventors

• 👤 Nobutoshi Torii
• 👤 Hiroshi Wakio

Bibliographic Details