HDD servo control development - Present and future

The hard disk drive (HDD) is one of the aggressive industries where they have been very eager to introduce new servo algorithms based on latest control theory. Several features of today´s HDD servo control are described. In this paper, I would like to propose an idea how to keep this activity of technology development. In each industry, there are still many issues to be solved by advanced control technologies, and each industry has had very good collaboration system with academy to try to realize innovative idea. At the same time, we can see several activities of mutual communications among industries. This communication may notify us other industries´ outcome which may trigger us thinking new idea. In order to achieve this, (1) it is necessary to continue submitting a kind of survey paper describing comprehensive technology development trend, and (2) it is also necessary to disclose the best practice servo control by the benchmarking