Disturbance Observer Filter for Head Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing data storage devices face challenges in accurately positioning the head over a disk due to disturbances such as vibrations, which affect the precision and stability of read/write operations, as current servo control systems struggle to effectively compensate for these disturbances.
Innovation Solution
The implementation of a disturbance observer filter with band-pass filters that adjust the center frequency, gain, and bandwidth to generate an actuator control signal that compensates for disturbances, ensuring precise head positioning by filtering the position error signal and generating a disturbance compensation signal to stabilize the actuator control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a traditional servo control system is used for head positioning, then the system structure remains simple, but the positioning precision deteriorates due to inability to effectively compensate for disturbances such as vibrations
Solution Approach 1:
The patent implements a disturbance observer filter that uses feedback from position error signals to continuously adjust and compensate for disturbances. The filter processes feedback information about the actual positioning errors and generates compensation signals that are fed back into the control system, creating a closed-loop feedback mechanism that effectively compensates for vibrations and other disturbances, thereby improving head positioning precision without requiring a completely new control architecture.
Solution Approach 2:
The disturbance observer filter dynamically adjusts its parameters including center frequency, bandwidth, and gain based on the characteristics of the disturbance signals. By changing these filter parameters in response to detected disturbance patterns, the system adapts to different vibration conditions and maintains optimal compensation performance across varying operating conditions, improving positioning precision while keeping the control system structure manageable.
2Stability of the object's composition
If disturbance compensation is added to the control system, then the stability of head positioning improves, but the device complexity increases
Solution Approach 1:
The disturbance observer filter acts as an intermediary component between the position error signal and the final control output. It processes the error signal, extracts disturbance information, generates compensation signals, and combines these with the original control signal. This intermediary approach allows the system to achieve stable positioning through structured signal processing rather than requiring complex direct control mechanisms, thereby improving stability while managing system complexity.
3Adaptability or versatility
If the disturbance observer filter uses fixed parameters, then the system response is fast, but the adaptability to different disturbance frequencies deteriorates
Solution Approach 1:
The patent implements a dynamic disturbance observer filter that automatically adjusts its parameters including center frequency and bandwidth based on the detected characteristics of disturbance signals. The filter transitions from static fixed parameters to dynamic adaptive parameters that respond to real-time disturbance conditions, enabling the system to maintain fast response while adapting to varying disturbance frequencies. This dynamic adjustment allows optimal performance across different operating conditions without requiring manual reconfiguration.
Data Source
AI summary
A data storage device is disclosed comprising a head actuated over a disk comprising tracks defined by servo sectors. A location of the head over the disk is measured based on the servo sectors, and a position error signal (PES) is generated representing a difference between a target location for the head and the measured location for the head. An actuator control signal (ACS) is generated in response to the PES, a disturbance compensation signal (DCS) is generated based on the PES and the ACS, and the DCS is filtered with a disturbance observer filter. The ACS is adjusted based on an output of the disturbance observer filter, and the head is actuated over the disk based on the adjusted ACS. The DCS is filtered with a plurality of band-pass filters, and the disturbance observer filter is adjusted based on the plurality of band-pass filters.