Method and apparatus for controlling the machining of mechanical pieces

An apparatus for checking a piece in rotation during the machining in a numerical control machine tool, said apparatus comprising:

• a checking head adapted to cooperate with the piece in rotation and emit electric signals indicative of the dimensions of the piece, and
• a processing and display device connected to the checking head and to the numerical control of the machine tool, and adapted to receive said signals from the checking head, detect and process instantaneous values, and provide the numerical control with signals indicative of the dimensions of the piece,
• wherein the processing and display device is adapted to perform, during the machining, the dynamic calculation of
• average values of said instantaneous values, and
• an instantaneous dimension of the piece on the basis of one of said calculated average values, of a variation index indicative of the variation of the average values during the machining, and of at least a correction coefficient,
• the processing and display device being adapted to provide the numerical control with said instantaneous dimension of the piece.