An Optimization-Based Framework for Simultaneous Plant-Controller Redesign

1994 ◽  
Vol 116 (2) ◽  
pp. 396-404 ◽  
Author(s):  
R. Beyers ◽  
S. Desa
Keyword(s):  
Dynamic System ◽  
Optimization Problem ◽  
Closed Loop ◽  
Optimization Problems ◽  
Dynamic Performance ◽  
Loop System ◽  
Nonlinear Controller ◽  
Closed Loop System ◽  
Central Notion ◽  
Computer Controlled

In this paper we develop a framework for the redesign of computer-controlled, closed-loop, mechanical systems for improved dynamic performance. A central notion which underlies the redesign framework is that, in order to achieve the best possible performance from a constrained closed-loop system, the plant and controller should be designed simultaneously. The framework is presented as the formulation and solution of a progression of optimization problems which establish the limits of performance of the dynamic system under various conditions of interest, thereby enabling the engineer to systematically establish the various redesign possibilities. Using a second order linear dynamic system and a nonlinear controller as an example, we demonstrate the application of the framework and substantiate the idea that in order to achieve the best possible performance from a constrained closed-loop system, the plant and controller should be redesigned simultaneously. We then show how the redesign framework can be used to select the best control strategy for a robotic manipulator from a dynamic performance standpoint. Finally, in order to demonstrate that the redesign framework yields solutions which the engineer can implement with confidence, we present the experimental verification of the numerical solution of a manipulator redesign optimization problem.

An Optimization-Based Framework for Simultaneous Plant-Controller Redesign

1990 ◽  
Author(s):  
Robert Beyers ◽  
Subhas Desa
Keyword(s):  
Performance Improvement ◽  
Closed Loop ◽  
Optimization Problems ◽  
Dynamic Performance ◽  
Mechanical Systems ◽  
Loop System ◽  
Closed Loop System ◽  
Central Notion ◽  
Computer Controlled

Abstract In this paper we develop a framework for the redesign of computer-controlled, closed-loop, mechanical systems for improved dynamic performance. A central notion which underlies the redesign framework is that, in order to achieve the best possible performance from a constrained closed-loop system, the plant and controller should be designed simultaneously. The framework is presented as the formulation and solution of a progression of optimization problems which enable the designer to systematically establish the various redesign possibilities. An example clearly demonstrates the underlying ideas as well as the use of the redesign framework for performance improvement.

Control of magnetic levitation system using recurrent neural network-based adaptive optimal backstepping strategy

2020 ◽  
Vol 42 (13) ◽  
pp. 2382-2395
Author(s):  
Armita Fatemimoghadam ◽  
Hamid Toshani ◽  
Mohammad Manthouri
Keyword(s):  
Neural Network ◽  
Recurrent Neural Network ◽  
Optimization Problem ◽  
Closed Loop ◽  
Magnetic Levitation ◽  
Backstepping Control ◽  
Loop System ◽  
Closed Loop System ◽  
Levitation System ◽  
Magnetic Levitation System

In this paper, a novel approach is proposed for adjusting the position of a magnetic levitation system using projection recurrent neural network-based adaptive backstepping control (PRNN-ABC). The principles of designing magnetic levitation systems have widespread applications in the industry, including in the production of magnetic bearings and in maglev trains. Levitating a ball in space is carried out via the surrounding attracting or repelling magnetic forces. In such systems, the permissible range of the actuator is significant, especially in practical applications. In the proposed scheme, the procedure of designing the backstepping control laws based on the nonlinear state-space model is carried out first. Then, a constrained optimization problem is formed by defining a performance index and taking into account the control limits. To formulate the recurrent neural network (RNN), the optimization problem is first converted into a constrained quadratic programming (QP). Then, the dynamic model of the RNN is derived based on the Karush-Kuhn-Tucker (KKT) optimization conditions and the variational inequality theory. The convergence analysis of the neural network and the stability analysis of the closed-loop system are performed using the Lyapunov stability theory. The performance of the closed-loop system is assessed with respect to tracking error and control feasibility.

A Versatile, Computer-Controlled, Closed-Loop System for Continuous Infusion of Muscle Relaxants

1993 ◽  
Vol 68 (11) ◽  
pp. 1074-1080 ◽  
Author(s):  
SAIED J. ASSEF ◽  
ROBERT L. LENNON ◽  
KEITH A. JONES ◽  
MICHAEL J. BURKE ◽  
TERRENCE L. BEHRENS
Keyword(s):  
Continuous Infusion ◽  
Closed Loop ◽  
Muscle Relaxants ◽  
Loop System ◽  
Closed Loop System ◽  
Computer Controlled

A VERSATILE COMPUTER-CONTROLLED CLOSED-LOOP SYSTEM FOR CONTINUOUS INFUSION OF MUSCLE RELAXANTS

1991 ◽  
Vol 75 (3) ◽  
pp. A467-A467 ◽  
Author(s):  
S. J. Assef ◽  
K. A. Jones ◽  
R. L. Lennon ◽  
M. J. Burke ◽  
T. L. Behrens
Keyword(s):  
Continuous Infusion ◽  
Closed Loop ◽  
Muscle Relaxants ◽  
Loop System ◽  
Closed Loop System ◽  
Computer Controlled

scholarly journals Disturbance Observer-Based Control for Trajectory Tracking of a Quadrotor

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1624
Author(s):  
Sang Wook Ha ◽  
Bong Seok Park
Keyword(s):  
Trajectory Tracking ◽  
Closed Loop ◽  
Control Method ◽  
Control Strategies ◽  
Hierarchical Control ◽  
Loop System ◽  
Nonlinear Controller ◽  
Closed Loop System ◽  
External Disturbances ◽  
Dynamic Surface

This paper presents a new control approach for the trajectory tracking of a quadrotor in the presence of external disturbances. Unlike in previous studies using hierarchical control strategies, a nonlinear controller is designed by introducing new state transformations that can use Euler angles as virtual control inputs. Thus, the proposed method can eliminate the timescale separation assumption of hierarchical control strategies. To estimate the external disturbances involved in the translational and rotational dynamics of the quadrotor, disturbance observers are developed. Using state transformations and estimates of external disturbances, we design a robust nonlinear controller based on the dynamic surface control method. The stability of the closed-loop system is analyzed without separation into two subsystems. From the Lyapunov stability theory, it is proven that all error signals in the closed-loop system are uniformly ultimately bounded and can be made arbitrarily small. Finally, simulation results are presented to demonstrate the performance of the proposed controller.

Nonlinear Vibration Reduction in Smart Structures Using Nonlinear Integral Resonant Controller

2015 ◽  
Author(s):  
Ehsan Omidi ◽  
Nima Mahmoodi
Keyword(s):  
Closed Loop ◽  
Smart Structures ◽  
Vibration Reduction ◽  
Excitation Frequency ◽  
Loop System ◽  
System Response ◽  
Nonlinear Controller ◽  
Closed Loop System ◽  
Wide Range ◽  
Resonant Controller

This paper discusses a new nonlinear controller for vibration reduction in nonlinear vibrating smart structures. Nonlinear Integral Resonant Controller (NIRC) applies additional damping to the closed-loop system of a nonlinear vibrating system, and reduces the vibration amplitude in a wide range of frequency domain. An approximate solution is obtained using a multi-layer implementation of the Method of Multiple Scales, steady-state amplitude-frequency response is obtained and closed-loop stability is examined. Effects of different controller parameters on system response are investigated, in addition to numerical simulation results. In contrast to the Positive Position Feedback approach, the closed-loop response of the controlled system via NIRC does not show any high-amplitude peak in the neighborhood of the suppressed resonant frequency. This makes the closed-loop system robust to variations in excitation frequency.

scholarly journals An implicit controller for the steel level regulation in a vacuum-based continuous casting process

2004 ◽  
Vol 2 (02) ◽  
Author(s):  
M. A. Barrón ◽  
J. González
Keyword(s):  
Continuous Casting ◽  
Iterative Procedure ◽  
Closed Loop ◽  
Dynamic Performance ◽  
Casting Process ◽  
Asymptotically Stable ◽  
Nonlinear Controller ◽  
Closed Loop System ◽  
Nonlinear Mathematical Model ◽  
Continuous Casting Process

A nonlinear mathematical model of a vacuum-based continuous casting process and an implicit nonlinear controller are developed. The aim of the controller is the regulation of the mold and tundish molten steel levels. In the proposed approach, the output error is designed to be asymptotically stable, and the current values of the control inputs are numerically determined using the Newton-Rapson iterative procedure. The dynamic performance of the closed-loop system is analyzed using computer simulations.

Ellipsoidal Lyapunov-based hybrid model predictive control for mixed logical dynamical systems with a recursive feasibility guarantee

2018 ◽  
Vol 41 (9) ◽  
pp. 2475-2487
Author(s):  
Alireza Olama ◽  
Mokhtar Shasadeghi ◽  
Amin Ramezani ◽  
Mostafa Khorramizadeh ◽  
Paulo R C Mendes
Keyword(s):  
Dynamical Systems ◽  
Model Predictive Control ◽  
Hybrid Model ◽  
Predictive Control ◽  
Robust Stability ◽  
Optimization Problem ◽  
Closed Loop ◽  
Loop System ◽  
Closed Loop System ◽  
Mixed Logical Dynamical

This paper proposes an ellipsoidal hybrid model predictive control approach to solve the robust stability problem of uncertain hybrid dynamical systems modelled by the mixed logical dynamical framework. In this approach, the traditional terminal equality constraint is replaced by an ellipsoid that results in a maximal positive invariant set for the closed-loop system. Then, a Lyapunov decreasing condition along with the robustness criterion is introduced to the optimization problem to achieve the robust stability of the closed-loop system. As the main advantages, the ellipsoidal terminal set proposed in this paper attains a larger domain of attraction along with the recursive feasibility guarantee. Moreover, the stability and robustness constraints are achieved by a lower prediction horizon, which leads to a smaller dimension optimization problem. In addition, to reduce the computational complexity of the corresponding optimization problem, a suboptimal version of the proposed algorithm is introduced. Finally, numerical and car suspension system examples show the capabilities of the proposed method.

Non-linear multivariable flight control of aircraft

1998 ◽  
Vol 212 (2) ◽  
pp. 137-144 ◽  
Author(s):  
S E Lyshevski
Keyword(s):  
Flight Control ◽  
Closed Loop ◽  
Dynamic Performance ◽  
Optimization Procedure ◽  
Loop System ◽  
Closed Loop System ◽  
Bounded Control ◽  
Performance Improvements ◽  
Non Linear ◽  
Linear Differential

Innovative design methods are needed for advanced aircraft in response to requirements towards substantial performance improvements. Functionally and operationally, the aircraft must be considered as the highly coupled non-linear multi-input multi-output system, i.e. the aerodynamics have to be mapped by non-linear differential or difference equations. To improve flying and handling qualities, to increase manœuvrability and to expand the operating envelope, an innovative optimization procedure is developed to design the constrained controllers for multi-input multi-output aircraft. In particular, a bounded control law is synthesized by employing the Hamilton-Jacobi theory, and the admissibility concept is used to study the stability of the resulting closed-loop system. The developed optimization procedure is applied to a non-linear ninth-order model of an AFTI/F-16 aircraft. A bounded controller is designed, and modelling results are presented to demonstrate the dynamic performance of the resulting closed-loop system.

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