Adaptive feedforward cancellation with gain and damping control system considering helium leakage in HDDs

Abstract

This study developed an adaptive feedforward cancellation system with gain and damping control for hard disk drives (HDDs). The system was developed to compensate for fluid-induced vibration due to helium leakage. Helium-filled HDDs are used in data servers around the world to support the information society. One of the concerns in helium-filled HDDs is the deterioration of positioning accuracy of the control system due to helium leakage. The proposed head positioning control system can compensate for the fluid-induced vibration by updating the characteristics of the control system in real-time. Real-time simulations based on MATLAB/Simulink were performed to demonstrate that fluid-induced vibrations due by helium leakage in the head positioning control system of HDDs can be compensated. The results indicated that the characteristics of the control system were updated in real-time to compensate for fluid-induced vibrations in conformity with the variation in characteristics due to helium leakage and that the fluid-induced vibrations can be adequately compensated.