Multivariable Adaptive Harmonic Steady-State Control for Rejection of Sinusoidal Disturbances Acting on an Unknown System

This paper presents an adaptive harmonic steady-state (AHSS) controller, which addresses the problem of rejecting sinusoids with known frequencies that act on a completely unknown multi-input multi-output linear time-invariant system. We analyze the stability and closed-loop performance of AHSS for single-input single-output systems. In this case, we show that AHSS asymptotically rejects disturbances.Comment: 6 pages, 2016 American Control Conference (ACC). IEEE, 201

Direct adaptive command following and disturbance rejection for minimum phase systems with unknown relative degree

This paper considers parameter-monotonic direct adaptive command following and disturbance rejection for single-input single-output minimum-phase linear time-invariant systems with knowledge of the sign of the high-frequency gain (first non-zero Markov parameter) and an upper bound on the magnitude of the high-frequency gain. We assume that the command and disturbance signals are generated by a linear system with known characteristic polynomial. Furthermore, we assume that the command signal is measured, but the disturbance signal is unmeasured. The first part of the paper is devoted to a fixed-gain analysis of a high-gain-stabilizing dynamic compensator for command following and disturbance rejection. The compensator utilizes a Fibonacci series construction to control systems with unknown-but-bounded relative degree. We then introduce a parameter-monotonic adaptive law and guarantee asymptotic command following and disturbance rejection. Copyright © 2006 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55957/1/945_ftp.pd

Direct Adaptive Dynamic Compensation for Minimum Phase Systems With Unknown Relative Degree

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57805/1/HoagUnknownRelDegTAC2007.pd

Retrospective Cost Adaptive Control of the NASA GTM Model

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83658/1/AIAA-2010-8404-930.pd

A Computational Study of the Performance and Robustness Properties of Retrospective Cost Adaptive Control

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83646/1/AIAA-2010-8011-332.pd

Retrospective Cost Adaptive Flow Control Using a Dielectric Barrier Discharge Actuator with Parameter-Dependent Modeling

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90730/1/AIAA-2011-1302-798.pd

Subsystem Identification of Feedback and Feedforward Systems with Time Delay

We present an algorithm for identifying discrete-time feedback-and-feedforward subsystems with time delay that are interconnected in closed loop with a known subsystem. This frequency-domain algorithm uses only measured input and output data from a closed-loop discrete-time system, which is single input and single output. No internal signals are assumed to be measured. The orders of the unknown feedback and feedforward transfer functions are assumed to be known. We use a two-candidate-pool multi-convex-optimization approach to identify not only the feedback and feedforward transfer functions but also the feedback and feedforward time delay. The algorithm guarantees asymptotic stability of the identified closed-loop transfer function. The main analytic result shows that if the data noise is sufficiently small and the cardinality of the feedback-candidate-pool set is sufficiently large, then the identified feedforward and feedback delays are equal to the true delays, and the parameters of the identified feedforward and feedback transfer functions are arbitrarily close to the true parameters. This subsystem identification algorithm has application to modeling human-in-the-loop behavior. To demonstrate this application, we apply the new subsystem identification algorithm to data obtained from a human-in-the-loop control experiment in order to model the humans’ feedback and feedforward (with delay) control behavior

Retrospective Cost Adaptive Control of Low-Reynolds Number Aerodynamics Using a Dielectric Barrier Discharge Actuator

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83610/1/AIAA-2010-4841-142.pd

Investigation of Cumulative Retrospective Cost Adaptive Control for Missile Application

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83634/1/AIAA-2010-7577-578.pd

Comments on ‘output feedback adaptive command following and disturbance rejection for nonminimum phase uncertain dynamical systems’

We provide numerical examples and analysis to show that the adaptive controller given by Theorem 3.1 of Yucelen et al. 1 may fail to stabilize plants under the stated conditions. Copyright © 2011 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83465/1/1235_ftp.pd