An error-based observer improved by the repetitive control strategy for electro-optical tracking systems

• Introduces a composite control structure combining an enhanced error-based observer with repetitive control for electro-optical tracking systems. • Targets two complex disturbance types: periodic harmonic disturbance and narrow-band peak periodic disturbance, ensuring stability while suppressing disturbances across multiple frequencies. • Provides rigorous proofs of stability and efficacy, addressing limitations of existing disturbance suppression methods. • Validates the proposed methods through an experimental electro-optical tracking platform, demonstrating reliable performance under various operating conditions.