Stabilization of Two Electricity Generators

In this research, a sliding mode regulator with sine mapping is suggested for the stabilization of electricity generators being affected by magnet interaction nonlinearities and generator nonlinearities. To reach this goal, our suggested regulator has the following contributions: (a) it starts from the sliding mode regulator with the modifications that the saturation mapping is used to reach a smoother performance instead of the signum mapping, and the sine mapping is applied to reach an upper bound in the proportional gain error, (b) it is used to reach some chosen constant behaviors for the angle position, angle speed, and current in the electricity generators, and (c) its stabilization is ensured based on the Lyapunov approach. We show the simulation of the suggested regulator in two electricity generators.

Technical note: Mapping surface saturation dynamics with thermal infrared imagery

In this study we assess the practicability of applying thermal infrared (TIR) imagery for mapping surface saturation dynamics. The advantage of TIR imagery compared to other surface saturation mapping methods is its large spatial and temporal flexibility combined with a non-invasive and intuitive character. Based on an 18-month field campaign, we review and discuss the methodological principles, under which conditions the method works best and what problems may occur. These considerations enable to plan efficient TIR imagery mapping campaigns and to benefit from the full potential offered by TIR imagery, which we demonstrate with several application examples. In addition, we elaborate on image post-processing and test different methods for the generation of binary saturation maps from the TIR images. The method testing is performed on various images with different image characteristics. Results show that the best method in addition to a manual image classification is a statistical-based approach that combines distribution fitting of two pixel classes, adaptive thresholding and region growing.