Control of high-precision mechatronic systems

A distinction can be made based on motion range (“long” indicating meter-scale, “short” indicating mm scale), and accuracy (micrometer or sub-nanometer). Long-range actuators typically have a moderate accuracy but suffer from nonlinearities like friction, requiring compensation methods using adaptive or learning techniques. Nonlinearities also play a role when using piezo materials for actuation in high-accuracy applications, possibly simultaneously with using the material as sensor (“self-sensing”). Finally, control techniques to improve sub-nanometer positioning systems have to deal with position dependency, in particular in the observation of dynamic modes in the measurement system. This has led to position-dependent observers creating the option of increasing control bandwidth.