<p>This article investigates an output feedback controller for overhead crane systems subject to double-pendulum dynamics, variable cable length, and input saturation. Although the traditional proportional-derivative controller can be directly derived from the crane’s mechanical energy, it does not incorporate information from unactuated variables. To introduce swing-related information into the closed-loop system, the virtual position is defined, which is the composite signal that incorporates both the actuated positions and the unactuated swing angles. Based on that, a new energy storage function is shaped from the mechanical energy, with dissipation achieved along the velocity of the virtual position. An anti-swing control scheme is then developed using the coupled energy representation, which is applicable to overhead cranes with up to seven degrees of freedom. Furthermore, the proposed control structure preserves the simplicity of PD design, requires no velocity measurements, while having explicit saturation amplitudes. The stability of the closed-loop system is established utilizing the Lyapunov analysis. Simulation and experimental results are presented to validate the effectiveness and superior performance of the proposed scheme.</p>