Fly Height Actuator Temperature Compensation Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Data storage devices face challenges in maintaining optimal head positioning and temperature control, as increasing ambient temperature can lead to head component degradation, affecting write and read operations due to increased fly height and temperature, which existing technologies struggle to mitigate effectively.

Innovation Solution

Implementing a fly height actuator (FHA) control system that adjusts the head's fly height based on measured temperature, disabling temperature compensation when a quality metric falls below a threshold to reduce heating effects, and re-enabling it when performance improves, using a calibrated control setting to maintain data recoverability and signal quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If temperature compensation is enabled to maintain head positioning accuracy at elevated temperatures, then head positioning precision is improved, but head component degradation accelerates due to increased heating effects

Engineering Contradiction:

Improvehead positioning precisionVSAvoidhead component reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent implements dynamic switching between temperature compensation mode and non-compensation mode based on real-time quality metric monitoring. The system transitions from a static temperature compensation approach to a dynamic adaptive control system that adjusts compensation activation based on operational conditions and component health status.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system continuously monitors quality metrics (such as read signal quality, write signal quality, or error rates) and uses this feedback to determine when to disable temperature compensation. This closed-loop feedback mechanism allows the system to detect degradation trends and adjust compensation activation accordingly, preventing further component damage while maintaining data integrity.

Inventive Principle:

Principle #23Feedback

2Temperature

If fly height is increased to reduce heating effects on head components, then head temperature is reduced, but data storage density and read/write signal quality deteriorate

Engineering Contradiction:

Improvehead component temperatureVSAvoidread/write signal quality

Core Design Contradiction:

TemperatureVSMeasurement precision

Solution Approach 1:

The system dynamically adjusts fly height based on temperature conditions and quality metric feedback. During normal operation, the fly height is optimized for data density. When temperature compensation is disabled due to component degradation, the system adjusts fly height to balance thermal management with signal quality requirements.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the fly height parameter adaptively based on operational mode (temperature compensation enabled/disabled). When compensation is disabled, the system modifies fly height parameters to mitigate the impact of increased head-media spacing on signal quality, potentially through adjustments in read/write current or equalization parameters.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If temperature compensation is continuously enabled to maintain optimal fly height, then data storage reliability is improved, but energy consumption increases and component degradation accelerates

Engineering Contradiction:

Improvedata storage reliabilityVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

Instead of continuous temperature compensation activation, the system employs periodic quality metric monitoring and intermittent compensation activation. The system checks quality metrics at defined intervals and activates compensation only when conditions warrant it, reducing unnecessary energy consumption and thermal stress on components.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system maintains data storage reliability through continuous quality metric monitoring, even when temperature compensation is disabled. By continuously assessing system health and enabling compensation only when needed, the system ensures reliable operation while minimizing energy waste from continuous compensation activation.

Inventive Principle:

Principle #20Continuity of useful action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach helps maintain data integrity and signal quality by adjusting the head's fly height to manage temperature-related degradation, ensuring reliable operations even at elevated ambient temperatures, while minimizing overheating and maintaining data recoverability.

Implementation Method 1

a fly height actuator (FHA) configured to adjust a fly height of the head over the disk

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS10878844B1Data storage device controlling head fly height based on temperature

Publication Date: 2020.12.29 WESTERN DIGITAL TECHNOLOGIES INC

AI summary

A data storage device is disclosed comprising a head actuated over a disk, wherein the head comprises a fly height actuator (FHA) configured to adjust a fly height of the head over the disk. A temperature of the data storage device is measured, and the FHA is controlled as a function of the measured temperature. A first quality metric of the data storage device is measured, and when the first quality metric falls below a threshold, the FHA control as a function of the measured temperature is disabled and the FHA is controlled to decrease the fly height of the head.