The system that can recognize whether a pinhead is inaccurate fitting and location in hackle is introduced.The system includes several parts: lamp-house

pick-up camera

movement control card

step motor

hackle and switch.Image collected by pick-up camera is auto-threshold

binary

located and template matched.As there is a tilt between hackle and pins

collected image must be rectified before matching template.After the comparison of template and searching graph

the system can get similarity automatically

the inaccurate fitting pinhead can be recognized easily

and it also can give an alarm while there is inaccurate fitting.