Servo bandwidth and positioning accuracy design for high track density disk drives

• Published in: IEEE transactions on magnetics Vol. 36; no. 5; pp. 2216 - 2218
• Main Authors: Yamaguchi, T., Usui, K., Okuyama, A., Yasuna, K., Akagi, K., Shishida, K.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.09.2000; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Accuracy; Actuators; Applied sciences; Bandwidth; Control systems; Crossovers; Density; Design engineering; Disk drives; Electric shock; Electronics; Exact sciences and technology; Laboratories; Magnetic devices; Magnetism; Mechanical engineering; Other magnetic recording and storage devices (including tapes, disks, and drums); Position errors; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Servomechanisms; Target tracking; Vibrations; Head position; Positioning; Position control; Bandwidth; Theoretical study; Magnetic head; Magnetic disk; Recording; Servomechanism; Magnetic recording
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/20.908364

Possibility of achieving positioning accuracy to meet the areal density of 40 Gb/in/sup 2/ has been studied. Stationary and nonstationary position errors are shown, and the servo design approaches have been proposed. A precise model of head-positioning system has been developed, and the required open loop servo bandwidth is estimated using the model. The experimental results using 2.5-inch HDD show that 750 Hz to 1 kHz servo bandwidth (open loop crossover frequency) is effective to achieve 40 nm positioning accuracy during track-following to meet 60 kTPI for 40 Gb/in/sup 2/.