Modelling of linear motor feed drives for grinding machines

Modeling of a linear motor feed drive including pre-rolling friction and aperiodic cogging and ripple

“…Cogging force and force ripple are described in several works, including [18,29]. Force ripple is an electromagnetic effect by which the motor force constant varies with position and is represented by periodic functions in [3,20,32].…”

“…There is a number of models capable of representing friction behavior to some extent. A model which has been widely used is the LuGre model [4], a single-state dynamic model which captures most of the observed phenomena and has already been used to model friction on linear motors in [29]. However, it cannot reproduce accurately the nonlocal memory characteristics of pre-sliding friction [11] and, under certain conditions, may even exhibit steadystate motion below breakaway force [7].…”

“…However, in this case, modeling and identification are performed for a linear motor in which force ripple and cogging force are not an issue. In [29], a model for a linear motor that includes these effects is given in the context of a drive used in a grinding process. Nevertheless, it does not take into account the electrical dynamics.…”

Deterministic robust control design for an iron core linear drive including second-order electrical dynamics

“…There have been many approaches for the control of linear motors, such as a feedforward and state feedback controller; 1 a technique called nominal characteristic trajectory following; 2,3 repetitive control; 4 a proportional-integral-derivative (PID)-based controller; 5 an improved sliding mode controller in the work by Xie; 6 and several model-based adaptive robust controllers 7–11 based on the work by Yao, 12,13 just to cite a few. Model-based controllers often have high robustness.…”