P. Ioannou, Principal Investigator and A. Despain, Co-Investigator, Acorn Tech. Inc.
The reliance on linear time invariant models for control design has reached a level of maturity that is often characterized by limitations on possible performance improvements in many applications, a classical example being the hard disk drive servo control problem. The use of more realistic nonlinear models for nonlinear control design has been an active area of research which produced many new control methodologies during the recent years. Despite these remarkable advances, the control of nonlinear systems is still at its infancy. The purpose of this project is the development of nonlinear adaptive control methodologies for a wide class of nonlinear plants with partially or fully unknown nonlinearities with guaranteed pre specified tracking accuracy. These nonlinear techniques will be used to address the servo control problem of hard disk drives which is known to be one of the most challenging and exciting control problems. The discrete time counterparts of the developed control methodologies for continuous time systems will be generated and implemented on a disk drive test bed donated to the project by ACORN Technologies Inc.
The development of nonlinear adaptive control methodologies is fundamental to automation where high accuracy and performance is required despite environmental conditions, imperfections in manufacturing, worn out parts with time etc. The implementation of such sophisticated control techniques is now possible due to the advances in electronics and availability of low cost, high power computational tools. Nonlinear adaptive control techniques to be developed under this project can be used to push the performance envelope beyond the limits achievable using traditional control techniques in a wide range of applications leading to higher efficiency and lower cost operations. Tracking the data tracks in a computer disk drive for example more accurately will allow the squeeze of more tracks on a disk leading to smaller size disks with the same storage capacity. While the primary application to test the developed control techniques is the accurate tracking of data tracks in a disk drive, the techniques will be applicable to a wide range of applications involving high accuracy tracking and performance. Areas such as robotics, manufacturing, aerospace, chemical and mechanical systems which involve processes where accurate tracking and precision, despite manufacturing and environmental imperfections, is very crucial will benefit from the proposed research.
