1. N. E. Huang and S. S. Shen, Hilbert-Huang Transform and Its Applications Interdisciplinary Mathematical Sciences, vol. 5, World Scientific Publishing Co. Pte. Ltd, 2005.
2. Z. Cao and G. Ledwich, “Tracking variable periodic signals with fixed sampling rate,” Proceedings of the 40th IEEE Conference on Decision & Control, Orlando, USA, December 2001.
3. T. Jolly, T. C. Tsao, and J. Bentsman, “Rejection of unknown periodic load disturbances in continuous steel casting process using learning repetitive control approach,” Proceedings of IEEE International Symposium on Intelligent Control, pp. 36–41, 1993.
4. Z. H. Luo and B. Mahawan, “Repetitive control of tracking systems with time-varying periodic references,” Proceed-(a) (b) (c) Fig. 20. Experimental result with variable instantaneous frequencies period’s signal: (a) the disturbance input, (b) error response, and (c) control output. ings of the 37th IEEE Conference on Decision & Control, Tampa, USA, 1998.
5. M. C. Tsai and W. S. Yao, “Design of a plug-in type repetitive controller for periodic inputs,” IEEE Transactions on Control Systems Technology, vol. 10, no. 4, pp. 547–555, 2002.