Output Regulation in Discrete-Time Bimodal Linear Systems Subject to Deterministic and Random Exogenous Input Signals

2010 ◽  
Author(s):  
Zhizheng Wu ◽  
Foued Ben Amara
Keyword(s):  
Linear Systems ◽  
Discrete Time ◽  
Hard Disk Drives ◽  
Output Regulation ◽  
Switched System ◽  
Flying Height ◽  
Random Disturbances ◽  
H2 Performance ◽  
Proposed Regulation ◽  
Exogenous Signals

This paper considers an output regulation problem for a class of discrete-time switched bimodal linear systems against known deterministic exogenous signals in the presence of unknown random disturbances, which is motivated by the flying height regulation problem in hard disk drives. The regulation problem for the switched system against the known deterministic exogenous signals is approached by constructing a set of observer-based parameterized stabilizing controllers that satisfy a sufficient regulation condition for the switched system. An H2 performance constraint is then added to identify, from among the already constructed regulators, those that provide the best H2 performance against the unknown random disturbances. The proposed regulator is successfully evaluated on a bimodal switched mechanical system experimental setup to demonstrate the effectiveness of the proposed regulation approach.

Output Regulation in Bimodal Systems With Application to Surface Tracking in the Presence of Contact Vibrations

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Zhizheng Wu ◽  
Foued Ben Amara
Keyword(s):  
Output Regulation ◽  
Synthesis Algorithm ◽  
Stabilizing Controllers ◽  
Surface Tracking ◽  
Input Signals ◽  
Random Components ◽  
Random Disturbances ◽  
Proposed Regulation ◽  
Regulation Approach ◽  
Contact Vibrations

Motivated by a class of surface tracking problems in mechanical systems subject to contact vibrations, this paper considers a regulation problem for discrete-time switched bimodal linear systems where it is desired to achieve output regulation against exogenous input signals featuring known deterministic and unknown random components. A first step in the regulator design involves constructing a set of observer-based parameterized stabilizing controllers that satisfy a sufficient regulation condition for the switched system against the known deterministic disturbance or reference signals. In the second step, an additional performance constraint is added to identify, from among the already constructed regulators, those that provide the best regulation performance against the unknown random disturbances. A corresponding regulator synthesis algorithm is developed based on iteratively solving properly formulated bilinear matrix inequalities. The proposed regulator is successfully evaluated on an experimental setup involving a switched bimodal mechanical system subject to contact vibrations, hence demonstrating the effectiveness of the proposed regulation approach.

Semi-global output regulation for discrete-time singular linear systems with input saturation via composite nonlinear feedback control

2016 ◽  
Vol 39 (3) ◽  
pp. 352-360 ◽  
Author(s):  
Xiaoyan Lin ◽  
Dongyun Lin ◽  
Weiyao Lan
Keyword(s):  
Feedback Control ◽  
Linear Systems ◽  
Discrete Time ◽  
Input Saturation ◽  
Output Regulation ◽  
Control Law ◽  
Nonlinear Feedback Control ◽  
Nonlinear Feedback ◽  
Composite Nonlinear Feedback ◽  
Singular Linear Systems

The semi-global output regulation problem of multi-variable discrete-time singular linear systems with input saturation is investigated in this paper. A composite nonlinear feedback control law is constructed by using a low gain feedback technique for semi-global stabilisation of discrete-time singular linear systems with input saturation. The sufficient solvability conditions of the semi-global output regulation problem by composite nonlinear feedback control are established. When the composite nonlinear feedback control law is reduced to a linear control law, the solvability conditions are an exact discrete-time counterpart of the semi-global output regulation problem of continuous-time singular linear systems. With the extra control freedom of the nonlinear part in the composite nonlinear feedback control law, the transient performance of the closed-loop system can be improved by carefully choosing the linear feedback gain and the nonlinear feedback gain. The design procedure of the composite nonlinear feedback control law and the improvement of the transient performance are illustrated by a numerical example.

scholarly journals Adaptive output regulation for linear systems via discrete-time identifiers

Automatica ◽  
2019 ◽  
Vol 105 ◽  
pp. 422-432 ◽  
Author(s):  
Michelangelo Bin ◽  
Lorenzo Marconi ◽  
Andrew R. Teel
Keyword(s):  
Linear Systems ◽  
Discrete Time ◽  
Output Regulation

scholarly journals Output Regulation in Discrete-Time Switched Bimodal Systems Based on Youla Parameterized Stabilizing Controllers

2012 ◽  
Vol 2012 ◽  
pp. 1-19 ◽  
Author(s):  
Zhizheng Wu ◽  
Foued Ben Amara
Keyword(s):  
Discrete Time ◽  
Output Regulation ◽  
Linear Matrix ◽  
Control Problems ◽  
Matrix Inequalities ◽  
Synthesis Algorithm ◽  
Stabilizing Controllers ◽  
Proposed Regulation ◽  
Regulation Approach ◽  
Performance Constraint

Motivated by a class of contact vibration control problems in mechanical systems, this paper considers a regulation problem for discrete-time switched bimodal linear systems where it is desired to achieve output regulation against partially known deterministic and unknown random exogenous signals. First, a set of observer-based Youla parameterized stabilizing controllers is constructed, based on which the regulation conditions for the switched system against the deterministic signals along with anH2performance constraint against the unknown random signals are derived. Then a corresponding regulator synthesis algorithm is developed based on solving properly formulated linear matrix inequalities. The proposed regulator is successfully evaluated on an experimental setup involving a switched bimodal mechanical system subject to contact vibrations, hence, demonstrating the effectiveness of the proposed regulation approach.

Flying Height Control for a 2-DOF Tripad Slider in Hard Disk Drives With Switched Regulator

2005 ◽  
Author(s):  
Zhizheng Wu ◽  
Foued Ben Amara
Keyword(s):  
Control Method ◽  
Hard Disk Drives ◽  
Surface Profile ◽  
Hard Disk ◽  
Disk Surface ◽  
Switched System ◽  
Flying Height ◽  
Disk Drives ◽  
The Stability ◽  
Adaptive Regulator

Maintaining a constant small flying height of the read/write head is an important target in the design of the ultra high storage density hard disk drives. One effective way to achieve this goal is to use a feedback regulator to suppress the flying height variations. For low flying heights, the read/write head enters into intermittent contact with the disk surface, which results in a switched system regulation problem. In this paper a new control method is proposed to maintain the flying height at its desired value based on the switched system models, despite the unknown microwaviness in the disk surface profile and the unpredictability in the switching times. First, a switched system model is constructed. Then, a Q parameterized set of switched regulators is constructed and the stability of the resulting switched closed loop system is analyzed. Online adaptive regulator tuning is then performed by adjusting the Q parameter in the controller to achieve regulation. Simulation results are presented to illustrate the effectiveness of the proposed method.

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