Position control in normal direction for the fast screw-tightening

Screws are widely used in various types of manufactured product. For screw-tightening, the pushing force and rotary torque are required. However, usually only the rotary torque is controlled in order to control the screw-tightening process and the pushing direction is important. If the pushing force becomes small, the driver-head separates from a screw. On the other hand, if the pushing force becomes large, the friction also becomes large and increase of the pushing force is needed. Therefore, the pushing force has relationship to the rotary torque. This paper focuses on the pushing direction and the aim of the research is the fast screw-tightening. This paper shows the modified screw-tightening model. Moreover, the pushing positon is controlled based on the rotary angle to reduce the reaction force for the fast screw-tightening. The availability of proposed method is verified by the simulation and experiment.