Disturbance observers and applications

Abstract

The control performance of practical systems has inevitably suffered from various disturbances and uncertainties, including external environmental disturbances, unknown model uncertainties (possibly caused by unmodelled dynamics) and parameter perturbations. The development of disturbance observation and attenuation methods and technologies has received a great deal of attention for practical engineering systems. The new generations of control systems require increasingly higher control performance accuracy, and thus higher disturbance rejection abilities. In addition, the complexity of practical systems is much greater than those currently dealt with, for example, the extremely high dimensionality of these complex systems. This will result in the degraded disturbance rejection performance of the existing methods and technologies. The main objective of this Special Issue (SI) on ‘Disturbance Observers and Applications’ of the Transactions of the Institute of Measurement and Control is to present recent advances in disturbance observers and applications for practical control systems. The present SI will facilitate faster uptake of advanced disturbance observer technologies, as well as addressing new challenges arising from complex control systems, in order to give rise to new theories and methodologies. The interplay of disturbance observers and complex practical systems will largely advance the knowledge in both fields, resulting in much smarter methodologies and technologies to enhance the performance of the practical control systems. This SI consists of 16 papers selected from many highquality submissions through a strict peer-reviewed procedure. It covers some recent new progress in disturbance estimation and attenuations in both theoretical and application aspects. The contributions of the selected papers are categorised into four categories, which are briefly summarised as follows.