<p>Electro-hydraulic servo systems utilizing multi-stage hydraulic cylinders (MSHCs) in erection mechanisms face strong nonlinearities, time-varying loads, and model uncertainties that challenge conventional controllers. This paper develops and compares different control strategies for such systems: the classical proportional–integral–derivative controller (PID), a PID controller whose gains are tuned via particle swarm optimization (PSO), fractional-order PID tuned by PSO (FOPID–PSO), and a robust sliding mode control (SMC) scheme with Lyapunov-based design and a boundary layer implementation to mitigate chattering. A nonlinear model of the erection mechanism and MSHC, including inter-stage impacts captured by a Kelvin–-Voigt impact model and controlled by a proportional directional control valve, is formulated and simulated using MATLAB/Simulink. Results show that PSO-optimized PID significantly improves tracking and settling behavior over baseline PID, FOPID–PSO adds flexibility to the PID, while robust SMC maintains accuracy and disturbance rejection under large load variations, but with a pronounced peak control signal during the stage transition interval. The study quantifies performance, demonstrating that the control approaches enhance stability and robustness, with SMC offering strong resilience to uncertainties and PSO providing a simple and high-performance tuning route for implementation. The results are based on numerical simulation and serve as a baseline for future experimental validation and hardware realization.</p>