scholarly journals Reduced Order Model of Position Control System

2011 ◽  
pp. 113-115
Author(s):  
Yogesh V. Hote ◽  
A. N. Jha ◽  
J. R. P. Gupta
Keyword(s):  
Control System ◽  
Position Control ◽  
Open Loop ◽  
Simple Approach ◽  
Reduced Order Model ◽  
Order Model ◽  
Reduced Order ◽  
Reduced Order Modelling ◽  
Position Control System

In this paper, simple approach is proposed to determine reduced order model of a unstable open-loop position control system. This approach is based on Krishnamurthy’s approach on Routh criterion on reduced order modelling. The results are simulated in Matlab environment.

Reduced optimal controller design for the nuclear reactor power control system

2011 ◽  
pp. 84-86
Author(s):  
H. Zarabadipour ◽  
H. Emadi
Keyword(s):  
Control System ◽  
Power Control ◽  
Nuclear Reactor ◽  
Reactor Power ◽  
Reduced Order Model ◽  
Optimal Controller ◽  
Balance Model ◽  
Order Model ◽  
Reduced Order ◽  
Power Control System

The power control system of a nuclear reactor is one of the key systems that concern the safe operation of the plant. Much attention is paid to the power control systems’ performance of nuclear reactor in engineering. The goal of this paper is apply balance model reductionto derive reduced order model and then design the reduced optimal controller for nuclear reactor power system.The simulation results with reduced-order model and with optimized controller show that the proposed technique is improved .

scholarly journals A Novel Sliding Mode Control Framework for Electrohydrostatic Position Actuation System

2018 ◽  
Vol 2018 ◽  
pp. 1-22 ◽  
Author(s):  
Rongrong Yang ◽  
Yongling Fu ◽  
Ling Zhang ◽  
Haitao Qi ◽  
Xu Han ◽  
...  
Keyword(s):  
Sliding Mode Control ◽  
Position Control ◽  
Sliding Mode ◽  
Reduced Order Model ◽  
Design Solution ◽  
Order Model ◽  
Reduced Order ◽  
Mode Control ◽  
Actuation System ◽  
Mismatched Disturbances

A novel sliding mode control (SMC) design framework is devoted to providing a favorable SMC design solution for the position tracking control of electrohydrostatic actuation system (EHSAS). This framework is composed of three submodules as follows: a reduced-order model of EHSAS, a disturbance sliding mode observer (DSMO), and a new adaptive reaching law (NARL). First, a reduced-order model is obtained by analyzing the flow rate continuation equation of EHSAS to avoid the use of a state observer. Second, DSMO is proposed to estimate and compensate mismatched disturbances existing in the reduced-order model. In addition, a NARL is developed to tackle the inherent chattering problem of SMC. Extensive simulations are conducted compared with the wide adoption of three-loop PID method on the cosimulation platform of EHSAS, which is built by combining AMESim with MATLAB/Simulink, to verify the feasibility and superiority of the proposed scheme. Results demonstrate that the chattering can be effectively attenuated, and the mismatched disturbance can be satisfyingly compensated. Moreover, the transient performance, steady-state accuracy, and robustness of position control are all improved.

New Swash Plate Damping Model for Hydraulic Axial-Piston Pump

1999 ◽  
Vol 123 (3) ◽  
pp. 463-470 ◽  
Author(s):  
X. Zhang ◽  
J. Cho ◽  
S. S. Nair ◽  
N. D. Manring
Keyword(s):  
Open Loop ◽  
Operating Conditions ◽  
Reduced Order Model ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Order Model ◽  
Nonlinear Simulation ◽  
Reduced Order ◽  
Swash Plate ◽  
Axial Piston

A new, open-loop, reduced order model is proposed for the swash plate dynamics of an axial piston pump. The difference from previous reduced order models is the modeling of a damping mechanism not reported previously in the literature. An analytical expression for the damping mechanism is derived. The proposed reduced order model is validated by comparing with a complete nonlinear simulation of the pump dynamics over the entire range of operating conditions.

A Stabilization of Fixed Gain Controlled Infinite Dimensional Systems by Augmentation With Direct Adaptive Control

2017 ◽  
Author(s):  
Mark J. Balas ◽  
Susan A. Frost
Keyword(s):  
Closed Loop ◽  
Adaptive Controller ◽  
Open Loop ◽  
Reduced Order Model ◽  
Order Model ◽  
Reduced Order ◽  
Infinite Dimensional ◽  
Infinite Dimensional Systems ◽  
Transmission Zeros ◽  
Exponentially Stable

Linear infinite dimensional systems are described by a closed, densely defined linear operator that generates a continuous semigroup of bounded operators on a general Hilbert space of states and are controlled via a finite number of actuators and sensors. Many distributed applications are included in this formulation, such as large flexible aerospace structures, adaptive optics, diffusion reactions, smart electric power grids, and quantum information systems. We have developed the following stability result: an infinite dimensional linear system is Almost Strictly Dissipative (ASD) if and only if its high frequency gain CB is symmetric and positive definite and the open loop system is minimum phase, i.e. its transmission zeros are all exponentially stable. In this paper, we focus on infinite dimensional linear systems for which a fixed gain linear infinite or finite dimensional controller is already in place. It is usually true that fixed gain controllers are designed for particular applications but these controllers may not be able to stabilize the plant under all variations in the operating domain. Therefore we propose to augment this fixed gain controller with a relatively simple direct adaptive controller that will maintain stability of the full closed loop system over a much larger domain of operation. This can ensure that a flexible structure controller based on a reduced order model will still maintain closed-loop stability in the presence of unmodeled system dynamics. The augmentation approach is also valuable to reduce risk in loss of control situations. First we show that the transmission zeros of the augmented infinite dimensional system are the open loop plant transmission zeros and the eigenvalues (or poles) of the fixed gain controller. So when the open-loop plant transmission zeros are exponentially stable, the addition of any stable fixed gain controller does not alter the stability of the transmission zeros. Therefore the combined plant plus controller is ASD and the closed loop stability when the direct adaptive controller augments this combined system is retained. Consequently direct adaptive augmentation of controlled linear infinite dimensional systems can produce robust stabilization even when the fixed gain controller is based on approximation of the original system. These results are illustrated by application to a general infinite dimensional model described by nuclear operators with compact resolvent which are representative of distributed parameter models of mechanically flexible structures. with a reduced order model based controller and adaptive augmentation.

Detection and Isolation of Faults in Mobile Hydraulic Valves Based on a Reduced-Order Model and Adaptive Thresholds

2013 ◽  
Author(s):  
Jarmo Nurmi ◽  
Jouni Mattila
Keyword(s):  
Fault Detection ◽  
Open Loop ◽  
Reduced Order Model ◽  
Fault Detection And Isolation ◽  
Order Model ◽  
Isolation System ◽  
Reduced Order ◽  
Adaptive Thresholds ◽  
Hydraulic Valves ◽  
Hydraulic Valve

Detecting and isolating faults in complex engineering systems is important for properly planning maintenance, and it leads to decreases in down and repair times and to an increase in system performance. Mobile hydraulic valves, which are characterized by functions such as pressure-compensation and pilot-operation, are such complex systems that they could tremendously benefit from a real-time, accurate fault detection and isolation system. However, the complexity of these valves means that accurate full-state modeling is generally difficult and time-consuming. This paper proposes a reduced-order model for the fault detection of an open-loop-controlled mobile hydraulic valve. This reduced-order model is used along with statistically computed adaptive thresholds for the purpose of enhancing the reliability of fault detection. The considered faults include valve spool jamming caused by hydraulic fluid impurities, leakages caused by wear-induced increased clearances between the valve spool and sleeve, and sensor faults. The reduced-order model omits the modeling of pressure compensator dynamics by using a measurement of the pressure compensator, and pilot pressure dynamics by measuring the pilot pressures that drive the main spool. Experimental results from a commercial mobile hydraulic valve controlling a 2-DOF hydraulic crane show the practicality of the reduced-order modeling and adaptive threshold arrangements in this fault detection task. As a downside, a reduced set of faults can be isolated with the reduced-order model, but as a future consideration a bigger set of fault patterns with a full model are given and compared with the results obtained.

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