Screw fastening fault assessment device, screw fastening device, screw fastening fault assessment method, and control program

A screw fastening fault assessment method, comprising:

• a first position acquisition step of acquiring, as a first position, an axial position of a driver when a screw is inserted into a screw hole and the screw is temporarily seated;
• a second position acquisition step of acquiring, as a second position, the axial position of the driver in a final fastening process after the screw is temporarily seated;
• and
• a fault assessing step of assessing that a fault has occurred in the screw fastening when the amount of change from the first position to the second position is greater than a threshold value.

A non-transitory computer readable recording medium storing a control program which is executed by a computer to:

• acquire an axial position of a driver;
• and
• assess that a fault has occurred in screw fastening when an amount of change from a first position to a second position in the axial position of the driver is greater than a threshold value during a final fastening process;
• wherein perform the final fastening process from a time of temporary seating after a screw is inserted into a screw hole and the screw is temporarily seated;
• and
• wherein the first position is an axial position of the driver when the screw is temporary seated, wherein the second position is an axial position of the driver in the final fastening process after the screw is temporarily seated.