Influence of the machine tool compliance on the dynamic performance of the servo drives

The development of large machinery in the industry of the machine tool implies moving heavy structural components and pieces. The consequence is the apparition of inaccuracies at the tool tip during the motion due to the high inertial forces acting on the compliant machine. To predict the dynamic behavior of these machines, a three degree of freedom mechatronic model has been developed considering the dynamics of the transmission chain of the drive, the machine structural element dynamics, and the control. The model can be used in the design stage to estimate the maximum jerk that can be commanded without the appearance of overshoot at the tool tip. Also, it can be used to predict the bandwidth of the whole mechatronic system. The model has been tested in a ball screw-based test bench with a compliant mass that simulates the structural compliance of a real large machine tool.