Active Damping of Chatter in Machine Tools - Demonstration with a ‘Hardware-in-the-Loop’ Simulator

Abstract

The motivation of the work is twofold: (a) understand the physics behind regenerative chatter and the influence of structural damping and (b) demonstrate an active damping technique based on collocated actuator/sensor pairs. A numerical stability analysis is performed using the root locus method and it is shown that, along with the structural poles, eigenvalues due to the delay parameter may contribute to instability. Since experimental demonstration of chatter in real machines is difficult, an alternative way of demonstration via a mechatronic simulator is presented, using the 'hardware-in-the-loop' concept. The mathematical model of the regenerative cutting process in turning is simulated in a computer and this is interfaced to a beam, representing the structural dynamics of the machine, via a displacement sensor and force actuator. In this way, a hardware and a software loop are combined. In a second step, an additional control loop is added, consisting of an accelerometer sensor and a collocated inertial actuator. Numerical and experimental stability lobe diagrams are compared, with and without active damping.

Vibration absorbers for chatter suppression: A new analytical tuning methodology

“…Active vibration absorbers [5,6] have also been proposed, since they can be more easily tuned than passive systems and can enable higher levels of energy dissipation. This approach is a special case of active vibration control, which has been applied to various machining chatter problems [7][8][9]. Despite the potential advantages of fully-active methods, passive tuned vibration absorbers remain a useful device for improving the chatter stability of machining systems, due to their lower complexity and cost.…”

Emulator-based control for actuator-based hardware-in-the-loop testing

“…Typically the hardware components being tested are control systems and the method has particular applications in the automotive industry (Hong et al, 2002;Misselhorn et al, 2006;Rulka & Pankiewicz , 2005) and a range of other applications (de Carufel et al, 2000;Ferreira et al, 2004a,b;Ganguli et al, 2005;Jezernik , 2005;Lambrechts et al, 2005;Mansoor et al, 2003).…”

Modelling and Simulation of a New Variable Stiffness Holder for Milling of Flexible Details

“…the use of cutting edge chamfers (Sellmeier and Denkena, 2012), using mechanical dampers (Kim et al, 2006) or smart materials (Rashid, 2005), robust optimum control (Moradi et al, 2013), active methods (i.e. active structural control (Dohner et al, 2004), active holder (Brecher et al, 2010), active damping (Ganguli et al, 2005;Parus et al, 2009;Kaliński and Galewski, 2014)), cutting with variable spindle speed (Soliman and Ismail, 1997; Kaliński and Galewski, 2011).…”