Fast and accurate identification of thermal dynamics for precision motion control: Exploiting transient data and additional disturbance inputs

Abstract Thermally induced deformations are becoming increasingly important for the control performance of precision motion systems. The aim of this paper is to identify the underlying thermal dynamics in view of precision motion control. Identifying thermal systems is challenging due to strong transients, large time constants, excitation signal limitations, large environmental disturbances, and temperature dependent behavior. An approach for non-parametric identification is developed that is particularly suitable for thermal aspects in mechatronic systems. In particular (1) reduced experiment time is achieved by utilizing transient data in the identification procedure. (2) an approach is presented that exploits measured ambient air temperature fluctuations as additional inputs to the identification setup. (3) the non-parametric model, obtained through (1) and (2), is used as a basis for parameter estimation of a grey-box parametric model. The presented methods form a complete framework that facilitates the implementation of advanced control techniques and error compensation strategies by providing high-fidelity models, enabling increased accuracy and throughput in high precision motion control.