Active vibration control of machine tool structures -: Part 2: An experimental active-vibration control system

The presented work is part of a project aimed at improving machine tool performance due to forced and self-excited vibration. Adaptive algorithms used in digital signal processing (DSP) are implemented in order to model machine tool structures and control the vibration. Self-excited machine tool vibration occurs when the cutting load exceeds the dynamic stiffness of the machine. The phenomenon is called chatter and has a direct impact on the surface finish, tool life and productivity. To avoid this, an experienced machine tool operator would try to change the cutting parameters or the clamping of the tool and work-piece. The aim for this research is to model machine tool structures adaptively in the digital domain, in order to control self-exited, but also forced vibration of machine tool structures. This means that the stiffness and damping of a machine tool structure could be changed actively during operation. The system presented here is a test rig, which is designed to show the potential of this approach and also the difficulties to overcome in order to control machine tool structures. This has been done through simulation and experimental validation.