Design of exponential stabilizing controller for open-loop unstable bilinear systems

2004 ◽  
Author(s):  
Yeas-Ren Hwang
Keyword(s):  
Open Loop ◽  
Bilinear Systems ◽  
Stabilizing Controller

Repetitive Process Control of Laser Metal Deposition

2014 ◽  
Author(s):  
Patrick M. Sammons ◽  
Douglas A. Bristow ◽  
Robert G. Landers
Keyword(s):  
Process Control ◽  
Dynamic Models ◽  
Open Loop ◽  
Metal Deposition ◽  
Hammerstein Model ◽  
Layer By Layer ◽  
Laser Metal Deposition ◽  
Material Source ◽  
Stabilizing Controller ◽  
Repetitive Process

The Laser Metal Deposition (LMD) process is an additive manufacturing process in which a laser and a powdered material source are used to build functional metal parts in a layer by layer fashion. While the process is usually modeled by purely temporal dynamic models, the process is more aptly described as a repetitive process with two sets of dynamic processes: one that evolves in position within the layer and one that evolves in part layer. Therefore, to properly control the LMD process, it is advantageous to use a model of the LMD process that captures the dominant two dimensional phenomena and to address the two-dimensionality in process control. Using an identified spatial-domain Hammerstein model of the LMD process, the open loop process stability is examined. Then, a stabilizing controller is designed using error feedback in the layer domain.

Persistence Filters for Estimation: Applications to Control in Shared-Sensing Reversible Transducer Systems

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Srikant Sukumar ◽  
Maruthi R. Akella
Keyword(s):  
Controller Design ◽  
Stable State ◽  
Control Design ◽  
Open Loop ◽  
Stabilizing Controller ◽  
State Observers ◽  
Technical Assumption ◽  
Schedule Design ◽  
Interesting Special Case ◽  
Nonlinear Extensions

We investigate state observer and feedback control design for systems with state- and time-dependent control or measurement gains. In this framework, we look at reversible transducers that are continually switched between the actuation and sensing modes at some prespecified schedule. Design and analysis of stable state-observers and feedback controllers for these classes of switched/hybrid systems are significantly complicated by the fact that, at any given instant of time, the overall system loses either controllability (during the sensing phase) or observability (during the actuation phase). In this work, we consider systems with scalar time-varying measurement gains and provide a novel observer construction that guarantees exponential reconstruction of state estimates to their true values. We go a step further to derive an exponentially stabilizing controller design that uses the state estimates resulting from our observer. This amounts to the establishment of a rather remarkable separation property of the control design. These developments hinge on a rather mild technical assumption, which can be interpreted for the reversible transducer problem as a persistent dwell time for both the sensing and actuation modes. An important feature here is that the convergence rate can be specified to any arbitrary value. Our theoretical results are validated through numerical simulations of challenging test-cases that include open-loop unstable systems. The paper also illustrates potential for nonlinear extensions of the observer based control design by considering an interesting special case.

scholarly journals Robust Control System Design for Multivariable Plants With Lightly Damped Modes

2007 ◽  
Author(s):  
D. Nelson-Gruel ◽  
P. Lanusse ◽  
A. Oustaloup ◽  
V. Pommier
Keyword(s):  
Control System ◽  
System Design ◽  
Transfer Matrix ◽  
Transfer Functions ◽  
Controller Design ◽  
Open Loop ◽  
Bench Mark ◽  
Control System Design ◽  
Stabilizing Controller ◽  
Robust Control System

A robust controller design is proposed for the active suspension system bench-mark problem. The CRONE control system design used is extended to unstable multivariable plants with lightly damped modes and RHP zeros. Decoupling and stabilizing controller K, is achieved for the open-loop transfer matrix. Fractional order transfer functions are used to define all the components of the diagonal open-loop transfer matrix, β. In defining the fractional open-loop transfer function β0i some elements of the plants, G0 and its inverse must be considered to achieve the stable controller. Optimisation provides the best fractional open-loop βopt. Finally, frequency domain system identification is used to find controller K=G0−1 βopt.

Predictive Control of Networked Control Systems with Time Varying Delay

2013 ◽  
Vol 446-447 ◽  
pp. 1239-1242
Author(s):  
Ling Li ◽  
Ye Guo Sun
Keyword(s):  
Control Systems ◽  
Predictive Control ◽  
State Feedback ◽  
Networked Control Systems ◽  
Open Loop ◽  
Networked Control ◽  
Feedback Controllers ◽  
Stabilizing Controller ◽  
Time Varying Delay ◽  
Varying Delay

In this paper, the predictive control of a class of networked control systems (NCSs) with time delay is investigated. Under the assumptions of forward completeness of the open-loop system and the existence of a stabilizing controller, state feedback and output feedback controllers are designed which achieves global asymptotic stability. Lastly, an illustrative example is given to demonstrate the effectiveness of the proposed results.

Magnetic control of continuum devices

2017 ◽  
Vol 36 (1) ◽  
pp. 68-85 ◽  
Author(s):  
Janis Edelmann ◽  
Andrew J Petruska ◽  
Bradley J Nelson
Keyword(s):  
Closed Loop ◽  
Numerical Solutions ◽  
Control Method ◽  
Open Loop ◽  
Stabilizing Controller ◽  
Loop Control ◽  
Boundary Constraints ◽  
Stable Direction ◽  
Magnetic Components ◽  
Equilibrium Configurations

In this paper we apply Cosserat rod theory to catheters with permanent magnetic components that are subject to spatially varying magnetic fields. The resulting model formulation captures the magnetically coupled catheter behavior and provides numerical solutions for rod equilibrium configurations in real-time. The model is general, covering cases with different catheter geometries, multiple magnetic components, and various boundary constraints. The necessary Jacobians for quasi-static, closed-loop control using an electromagnetic coil system and a motorized advancer are derived and incorporated into a visual-feedback controller. We address the issue of solution bifurcations caused by the magnetic field by proposing an additional, stabilizing control method that makes use of system redundancies. We demonstrate the effectiveness of the model by performing 3D tip-position trajectories with root-mean-square distance errors of 2.7 mm in open-loop, 0.30 mm in closed-loop, and 0.42 mm in stabilizing closed-loop modes. The stabilizing controller achieved on average a factor of 1.6 increase in the restoring wrenches for the least stable direction.

Set of open-loop block-diagonalizers of transfer matrices

1989 ◽  
Vol 49 (1) ◽  
pp. 161-168
Author(s):  
A. Bülent Özgü Ler ◽  
Vasfi Eldem
Keyword(s):  
Open Loop ◽  
Transfer Matrices

On closed-loop equilibrium strategies for mean-field stochastic linear quadratic problems

2020 ◽  
Vol 26 ◽  
pp. 41
Author(s):  
Tianxiao Wang
Keyword(s):  
Optimal Control ◽  
Closed Loop ◽  
Optimal Control Problems ◽  
Mean Field ◽  
Open Loop ◽  
Time Inconsistency ◽  
Control Problems ◽  
Linear Quadratic ◽  
Linear Quadratic Optimal Control ◽  
Equilibrium Strategies

This article is concerned with linear quadratic optimal control problems of mean-field stochastic differential equations (MF-SDE) with deterministic coefficients. To treat the time inconsistency of the optimal control problems, linear closed-loop equilibrium strategies are introduced and characterized by variational approach. Our developed methodology drops the delicate convergence procedures in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. When the MF-SDE reduces to SDE, our Riccati system coincides with the analogue in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. However, these two systems are in general different from each other due to the conditional mean-field terms in the MF-SDE. Eventually, the comparisons with pre-committed optimal strategies, open-loop equilibrium strategies are given in details.

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