Adaptive Load-Disturbance Rejection Control for Servo Control via Disturbance Observer and Optimal Current Regulation

Abstract

Servo control systems are frequently subjected to various uncertainties during operation, including load torque fluctuations, internal parameter variations, etc. These factors inevitably degrade system performance, necessitating the implementation of advanced control strategies to ensure stable operation. To address these challenges, this paper introduces a control scheme based on a disturbance observer (DOB) to estimate variations in the total disturbance., and the identified disturbances are subsequently compensated into the q-axis current loop input via a feedforward mechanism, thereby mitigating the adverse effects of load torque. Furthermore, an adaptive speed controller is designed to replace the conventional proportional-integral (PI) speed loop. By establishing an adaptive law supported by a rigorous Lyapunov stability analysis, the system's speed tracking capability and dynamic performance are significantly enhanced. Finally, Finally, simulation and experimental results demonstrate that the proposed integrated control strategy exhibits superior robustness and effectively improves overall system performance, thereby validating the feasibility and effectiveness of the developed methodology.