Hierarchical fuzzy-tuned multiobjective optimization control for gantry cranes

Abstract

This work presents a hierarchical fuzzy-tuned multiobjective optimization control scheme for the horizontal moving process of gantry cranes. Initially, a multiobjective optimization controller is developed based on gantry crane dynamics, which transforms the control issue of gantry crane into a state-tracking optimization problem and accomplishes simultaneous optimization of multiple performance indexes through the weighting matrix configuration. To cope with the multiobjective optimization controller, an actuation signal modulator is designed using a linear interpolation algorithm, which transforms the step signal of terminal position into an asymptotic signal to improve the transient system performance. Furthermore, a PD-type fuzzy logic regulator is developed as the superior of multiobjective optimization controller to adaptively guide the control procedure by tuning and configuring the weighting matrix. Above three components (multiobjective optimization controller, actuation signal modulator, fuzzy logic regulator) compose the complete hierarchical control scheme. Then, stability of the proposed control scheme is testified through Lyapunov stability theorem, and performances of the control scheme are examined through a series of simulations. Finally, conclusions and assessment of the control scheme are summarized and discussed.