Mechatronics of a ball screw drive using an N degrees of freedom dynamic model

High-performance position control in machine tools can only be achieved modeling the dynamic behavior of the mechatronic system composed by the motor, transmission and control during the design stage. In this work, a complex analytical model of a ball screw drive is presented and integrated in a mechatronic model of the actuator to predict the dynamic behavior and analyze the impact of each component of the transmission. First, a simple 2-dof model is presented, and its analysis sets the basis for the development of a more complex model of several degrees of freedom, whose resulting fundamental transfer functions are represented using natural and modal coordinates. The modeling in modal coordinates carries a reduction of the transfer function that reduces computational work. The two models are compared and experimentally validated in time and frequency domains by means of experimental tests carried out on a specifically developed ball screw drive test bench.