<p>The control performance of Electric Power Steering (EPS) systems plays a pivotal role in ensuring vehicle stability and safety during operation. Conventional control algorithms commonly used in automotive systems often fail to deliver adequate steering control performance, leading to significant output errors. This paper proposes a novel robust control method that combines Sliding Mode Control (SMC) and Active Disturbance Rejection Control (ADRC). A Nonlinear Tracking Differentiator (NTD) is integrated into the proposed controller to enhance the system’s ability to track the reference signal, while an Extended State Observer (ESO) is employed to estimate the state variables. The novel contributions of this work includes: (i) a novel integration of SMC and ADRC is developed to combine their complementary strengths, achieving rapid convergence, high robustness, and reduced chattering without requiring an exact system model. (ii) an NTD is introduced to improve reference-tracking smoothness and transient response. (iii) a new assisted-torque map based on error functions is designed to ensure continuous phase transitions and prevent torque oversaturation. Simulation results show that the proposed controller reduces the tracking error to below 0.6% and achieves an estimation accuracy of up to 98.6%. Furthermore, overshoot, phase delay, sensor noise, and chattering are significantly mitigated. These findings demonstrate that the proposed control framework offers a practical and efficient solution for enhancing EPS system performance in modern vehicles.</p>