Method for detecting surface welding quality of friction stir welding

A method for detecting a surface welding quality of friction stir welding, comprising the following steps:

• (1) acquiring a continuous surface depth image of a welding seam;
• (2) intercepting surface depth image segments of the welding seam with a first predetermined step size, and dividing the intercepted surface depth image segments of the welding seam into a front reference region, a thinned region and a rear reference region;
• (3) judging whether flatness of the front reference region is less than a threshold, and if yes, taking a height of the front reference region at this point as a latest reference height;
• if no, judging whether the flatness of the rear reference region is less than the threshold, and if yes, taking a height of the rear reference region at this point as the latest reference height;
• if no, taking the reference height of the previous depth image segment as the latest reference height;
• and
• (4) calculating a difference between the latest reference height and an average height of the thinned region at this point to obtain a thinning amount.