Frequency-Based State-Feedback Controller Design for 3-DOF Tower Cranes Under Aerodynamic Disturbances

Abstract

This study presents a novel state-feedback controller for a three-degree-of-freedom (3-DOF) tower crane system, optimized via frequency-domain cost function minimization. Tower cranes are complex, underactuated systems highly susceptible to external perturbations, particularly aerodynamic wind loads. The proposed Frequency-Domain Cost Function Minimization-Based State-Feedback Controller (FCFM-SFC) approach leverages spectral analysis to refine the closed-loop response by shaping the plant's dynamic characteristics. Unlike the classical Linear Quadratic Regulator (LQR) and Linear Quadratic Integral (LQI) approaches, which are governed by time-domain constraints, the FCFM-SFC framework employs a frequency-based objective function to attenuate the harmonic components associated with wind disturbances. Comprehensive simulations under varying wind intensities demonstrate that the FCFM-SFC achieves superior trajectory tracking and robust disturbance rejection, while the benchmark LQR/LQI exhibits substantial performance degradation and tracking deviations under intense aerodynamic stress.