The invention discloses a normal measurement and adjustment method for drilling of the free-form surface of an
aviation thin-wall piece. The method includes the following steps that a
numerical control system of a
machine tool reads the
machine tool motion coordinates of a current drilling
point location; the current position vector of a tool tip and the current
direction vector of a tool shaft in a workpiece coordinate
system are calculated through changes of the
machine tool motion coordinates; the normal is obtained through multiplication cross of the tangent vector of the crosspoint of two space curves of the surface of the
aviation thin-wall piece, namely the actual normal of the drilling
point location of the workpiece is obtained; and the included angle between the current drilling direction and the actual normal of the current drilling
point location of the
aviation thin-wall piece is worked out, the posture of a tool or the aviation thin-wall piece needs to be adjusted when the value of the included angle is beyond the range required by the aviation manufacturing standard, and the normal drilling operation is conducted after adjustment is completed.
Measurement station switchover is not needed, and the normal detection and the tool tip
distance detection are completed through one-time measurement before drilling. The normal measurement and adjustment method has the advantages that the measurement accuracy is high, the application range is wide, and the measurement and adjustment efficiency is high.