Disturbance Observer

Rejecting Fast Narrow-Band Disturbances With Slow Sensor Feedback for Quality Beam Steering in Selective Laser Sintering
A fundamental problem arises in feedback control when the system is subject to fast disturbances but can only get slowly updated sensor …
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A Tutorial on Loop-shaping Control Methodologies for Precision Positioning Systems
Many servo systems require micro/nano level positioning accuracy. This requirement sets a number of challenges from the viewpoint of …
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An Inverse-Free Disturbance Observer for Adaptive Narrow-Band Disturbance Rejection With Application to Selective Laser Sintering
Selective laser sintering (SLS) is an additive manufactur- ing (AM) process that builds 3-dimensional (3D) parts by scan- ning a laser …
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Multi-band beyond-Nyquist Disturbance Rejection on a Galvanometer Scanner System
In many laser processing applications, galvanometer scanners are integrated to a larger system that creates external disturbances to …
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Multirate Forward-model Disturbance Observer for Feedback Regulation beyond Nyquist Frequency
A fundamental challenge in digital and sampleddata control arises when the controlled plant is subjected to fast disturbances with, …
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Overview and New Results in Disturbance Observer based Adaptive Vibration Rejection with Application to Advanced Manufacturing
Vibrations with unknown and/or time-varying frequencies significantly affect the achievable performance of control systems, …
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Adaptive Suppression of High-Frequency Wide-Spectrum Vibrations With Application to Disk Drive Systems
In the big-data era, requirements for storage capacity and access speed in modern Hard Disk Drive (HDD) systems are becoming more and …
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New Repetitive Control with Improved Steady-State Performance and Accelerated Transient
In repetitive control (RC), the enhanced servo performance at the fundamental frequency and its higher order harmonics is usually …
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Methods for Closed-loop Compensation of Ultra-high Frequency Disturbances in Hard Disk Drives and Hard Disk Drives Utilizing Same
The importance of safe and flexible disturbance rejection at high frequencies has been ever increasing in modem control systems. For …
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Methods for Closed-loop Compensation of Ultra-high Frequency Disturbances in Hard Disk Drives and Hard Disk Drives Utilizing Same
Optimal Decoupled Disturbance Observers for Dual-Input Single-Output Systems
A controller design is presented for directly shaping the sensitivity function in the feedback control of dual-input single-output …
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