Browse Prior Art Database

Adjusting the Read Write Head to the Track Center of Magnetic Disks

IP.com Disclosure Number: IPCOM000085666D
Original Publication Date: 1976-May-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Schaller, K: AUTHOR [+2]

Abstract

The method relates to servo control using sampled input values. A compensator prevents the controlled plant from being driven into saturation. Only one set of compensator coefficients is computed, without considering the plant saturation or constraint. This can be done in accordance with time optimal loop response criteria.

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Adjusting the Read Write Head to the Track Center of Magnetic Disks

The method relates to servo control using sampled input values. A compensator prevents the controlled plant from being driven into saturation. Only one set of compensator coefficients is computed, without considering the plant saturation or constraint. This can be done in accordance with time optimal loop response criteria.

If the control variable exceeds the saturation level or constraint of the plant, only the maximum permissible value is applied both to plant 4 and to the feedback path leading to the recursive part of the time discrete compensator where it is stored for subsequent sample computation.

A sampled data servo loop control arrangement thus provides a limiting circuit 3 or an equivalent program statement in the compensator to simulate the plant saturation. Circuits 1 and 2 for computing the samples each consist of one shift register driving a device for summing weighted outputs of the shift register stages, or equivalent storage locations and program statements.

If the saturation level is uncertain because of manufacturing, operating or aging tolerances the plant can be driven by the compensator, whereby the control variable is limited to a minimum worst-case constraint.

This method is not only suitable for servo but also for regulator problems.

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