This paper presents a sensorless vector control strategy that utilizes a sliding mode observer (SMO) and a phase-locked loop (PLL) for rotor flux and speed estimation in induction motors. While traditional SMOs excel in flux estimation, they tend to suffer from chattering due to their inherent switching characteristics, which can compromise system stability and control precision. To overcome this limitation, the paper introduces a super-twisting SMO for current and flux observation and enhances it by incorporating a pre-filter to mitigate high-frequency chattering. This improvement enhances the smoothness and phase angle accuracy of flux estimation, increases adaptability to motor parameter variations, and reduces the impact of harmonic disturbances. The pre-filter effectively suppresses high-frequency noise, improving flux estimation accuracy and ensuring robust dynamic performance across varying operating conditions. For speed estimation, an enhanced PLL is proposed, with an optimized structure to improve frequency tracking at low and variable speeds, while effectively eliminating steady-state errors in ramp frequency inputs. This results in high-precision speed estimation and rapid dynamic response. Additionally, the enhanced PLL improves the system′s adaptability to motor operating conditions, ensuring more stable and reliable speed observation and boosting control performance and disturbance rejection capability. Experimental results demonstrate that the proposed method reduces flux waveform distortion by about 20% compared to conventional SMO-based methods, significantly enhancing system robustness. The method shows excellent performance across various operating conditions, not only improving sensorless vector control accuracy but also enhancing motor reliability, providing a practical and effective solution for engineering applications.