Modeling and simulation of adaptronic drilling tool axes as the basis of control design

Abstract

Drilling bars with great overhang are used for the purpose of deep drilling. Vibrations of the drilling bar and changing cutting forces based on form and position errors of a pilot hole are interrupting influences within the manufacturing process. Therefore the Fraunhofer IPT is developing an intelligent adaptronic drilling tool which enables the use of different redundant adaptronic systems each consisting of piezoactuators, solid-state joints and sensors in order to improve the accuracy of the drilling process. This paper presents the physical state-space model of the static und dynamic behaviour of one adaptronic system as the basis for further control synthesis and describes a useful tool for the multidiscipline design of the system. The starting model parameters are calculated by FEM-simulation and are fitted to measured data by an optimisation-algorithm based on Newton’s method. By describing the piezoelectric hysteresis the linear model of the mechatronic transfer behaviour is extended to a nonlinear model, which is the starting point for complex control designs for adaptronic machine tools.