Very low compliance force control on a CNC lathe machine

This work demonstrates how to carry out contact operations in a very stiff contact situation. The experimental set up used is a CNC machine that carries out metals spinning. The controlled forces are the metal forming forces. The designed controller operates in a dynamic environment. The complete control system operates in a manner similar to reaction compensation. The force controller used can be viewed as an integrating on-off controller which has tightly controlled release of control efforts to the controllers. It brings in artificial damping that ensures the stability of the control system. The designed force controller operates within limited tool path disturbances. The controller requires the feed forward of a nominal tool path. The accuracy of the nominal tool path brings the force deviations to within a manageable level. A secondary contribution of this work is the design of a generic external control loop for commercial CNC machines that enables the sensor integration for visual servoing or active force control