Abstract: Based on the pick and place positioning requirement during SMD’s one by one inspection process,a visual positioning method is proposed to achieve accurate transportation for SMD with Multi Degrees Of Freedom(MDOF).According to the one by one inspection process and the inspection layout,the allowable error boundary,in which component could be transported into the component trough successfully,is calculated.Besides,visual positioning error compensation method is put forward respectively corresponding to the top-view and bottom-view visual systems.With the X-bar and R control chart analysis,experiment is conducted to prove the accuracy and stability of the visual positioning method.The experimental results proves the positioning method can boost the accuracy and assure the stability in transportation process,which provides guidelines for components’ efficient transportation and accurate positioning one by one in rolls of SMD’s full-inspection.

Key words: SMD, visual positioning, multi-degree of freedom, accurate transportation, X-bar and R control chart