Motor current prediction of a machine tool feed drive using a component-based simulation model

In recent times, simulation techniques have been rapidly accepted by the machine tool industry. However, most existing simulation studies have focused on a particular machine tool and described an entire machine tool feed drive as a single combined system. This paper presents a method to accurately predict motor current (torque) behavior and acquire a more generalized and accurate dynamic simulation model for a machine tool feed drive. To improve the generality, a component-based approach is introduced. In this approach, the feed drive model is composed of subcomponent models, and each component mechanism is then independently modeled. In the developed model structure, the parameters of the subcomponent model can easily be determined by using product datasheets or simple parameter identification based on motor current measurements. To enhance the model accuracy in predicting the motor current, an improved friction model including time-dependent frictional characteristics and rolling contact conditions was introduced to the simulation. The performance of the developed dynamic simulation model is demonstrated through a comparison with real machine tool behavior.