Detection of the Bolt Loosening Angle through Semantic Key Point Extraction Detection by Using an Hourglass Network

Figure 7

Recognition results for small rotation angles. (a) Rotation angle of 0.5°. (b) Rotation angle of 1°. (c) Rotation angle of 2°. (d) Rotation angle of 4°.

(a)

(b)

(c)

(d)