<p>The cranes under study are modeled as a seven-degree-of-freedom (7-DOF) system that involves jib slewing, trolley motion, and payload hoisting/lowering in three-dimensional space. First, generalized coordinates are introduced as the fundamental fully actuated variables (FAVs) for constructing the baseline fully actuated system (FAS). The resulting FAS enables a direct design framework for control. Within the FAS approach, the anti-swing task is reduced to achieving the desired closed-loop characteristics. To this end, the swing dynamics are decoupled and used to generate auxiliary signals for swing attenuation. The resulting signals are then fused into the FAV to form the improved FAS, and swing attenuation is promoted by constructing the desired closed-loop behavior. Furthermore, the relationship between the improved FAS and the swing dynamics is analyzed, showing that the control gains of the improved FAS affect the swing response. Consequently, a performance index is introduced to characterize the convergence of the FAVs and their influence on swing motion. The control gain is determined by minimizing this index, thereby ensuring the suppression of swing motion. Experimental results on the laboratory platform indicate that the proposed scheme improves anti-swing performance relative to the selected comparative control methods.</p>