Hardware-in-the-loop simulator for stability study in orthogonal cutting

• A complete development of a hardware-in-the-loop mechatronic simulator is presented for reproducing the equivalent behaviour of real turning processes.
• A novel structure based on a flexure with eddy currents damper is presented. The flexure offers very high linearity, which is very interesting for posterior simulations.
• Dimensionless approximation is employed in order to get the equivalence with real processes.
• The delay presented of the system is compensated and the required relative damping is implemented by means of a novel method.
• The successful simulation results of HIL for a particular turning case extracted from literature are presented.

The self-excited vibrations due to the regenerative effect, commonly known as chatter, are one of the major problems in machining processes. They cause a reduction in the surface quality and in the lifetime of mechanical elements including cutting tools. Furthermore, the experimental investigations of chatter suppression techniques are difficult in a real machining environment, due to repeatability problems of hard to control parameters like tool wear or position dependent dynamic flexibility. In this work, a mechatronic hardware-in-the-loop (HIL) simulator based on a flexible structure is proposed for dimensionless study of chatter in orthogonal cutting. Such system reproduces experimentally, on a simple linear mechanical structure in the laboratory, any stability situation which can be used to test and optimise active control devices. For this purpose, a dimensionless formulation is adopted and the delay related to the phase lag of the actuator and the controller employed on the HIL is compensated.