Development of an Active Damping System for Structural Chatter Suppression in Machining Centers

The presence of chatter vibrations is one of the main limitations of machining processes in terms of productivity, as they prevent obtaining the required surface finishes and decrease the life of tools and the mechanical elements of the machine. The use of active dampers governed by a control strategy permits an increase in structural damping without significantly changing the machine design. The main objective of this study is to improve the dynamic capabilities of the machine, and to increase the chatter-free region. This objective is achieved by the addition of an electromagnetic actuator located as close as possible to the cutting point. The electromechanical design of the actuator is described, and a novel double flexure guarantees a constant gap between the moving magnets and the coils. This smart mechatronic system allows the introduction of new additional functions: process and machine monitoring, chatter avoidance by spindle speed modification, and machine dynamics calibration. All of these functions enhance standard milling machines.