Prescribed Performance Control for Electro-Hydrostatic Erecting System Based on Dual-RISE Scheme

Unmodeled uncertainties, such as friction and stage-change collision of the hydraulic cylinder, along with system disturbances, exist in the multi-link erecting system and impede high-precision erecting angle tracking. To tackle these challenges, this study develops a novel control framework characterized by asymptotic prescribed performance based on a distributed dual robust integral of the sign of the error (Dual-RISE) for the electro-hydrostatic multi-link erecting system. First, a precise system model is established by integrating complex multi-link kinematics with the pressure-flow dynamics of the two-stage hydraulic cylinder. A prescribed performance function (PPF) and nonlinear error transformation are then introduced to strictly constrain the tracking error within predefined transient and steady-state boundaries. The proposed framework integrates a distributed dual-loop RISE architecture to simultaneously reject matched and unmatched uncertainties, mathematically enforcing semi-global asymptotic convergence of the tracking error to zero without requiring infinite high-gain feedback. Comparative experiments with Dual-RISE and VFPI controllers demonstrate superior tracking accuracy and boundary protection under different erecting conditions.