Optimal Feedback Control of Precision Paraboloidal Shell Structronic Systems

2002 ◽  
Author(s):  
H. S. Tzou ◽  
J. H. Ding
Keyword(s):  
Feedback Control ◽  
Elastic Shell ◽  
State Feedback Control ◽  
Optimal Feedback Control ◽  
External Control ◽  
Shell Shape ◽  
Linear Quadratic ◽  
Sensors And Actuators ◽  
Distributed Sensors ◽  
Paraboloidal Shell

Paraboloidal shell of revolution is a common shell shape used in aerospace, telecommunication, dome structures and many other engineering applications. A structronic shell system is defined as an elastic shell bonded or laminated with piezoelectric sensors and actuators and it is governed by either in-situ or external control electronics. A closed-loop control system of paraboloidal shell structronic system consists of distributed sensors/actuators and controller coupled with the elastic paraboloidal shell. State equation for the paraboloidal shell structronic system is derived and optimal linear quadratic (LQ) state feedback control is implemented, such that the “best” shell control performance with the least control costs can be achieved. The gain matrix is estimated based on minimizing a performance criterion function. Optimal control effects are compared with controlled responses with other non-optimal PD control parameters. Control effects of sensor/actuator patches at different locations with same size are studied and compared; control effects for different natural modes are also investigated.

scholarly journals An Optimal Feedback Control Strategy for Nonlinear, Distributed-Parameter Processes

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 758 ◽  
Author(s):  
Debaprasad Dutta ◽  
Simant Ranjan Upreti
Keyword(s):  
Feedback Control ◽  
Oil Recovery ◽  
Control Strategy ◽  
Moving Boundary ◽  
State Feedback Control ◽  
Optimal Feedback Control ◽  
Distributed Parameter ◽  
Optimal State ◽  
Non Linear ◽  
Feedback Control Strategy

In this work, an optimal state feedback control strategy is proposed for non-linear, distributed-parameter processes. For different values of a given parameter susceptible to upsets, the strategy involves off-line computation of a repository of optimal open-loop states and gains needed for the feedback adjustment of control. A gain is determined by minimizing the perturbation of the objective functional about the new optimal state and control corresponding to a process upset. When an upset is encountered in a running process, the repository is utilized to obtain the control adjustment required to steer the process to the new optimal state. The strategy is successfully applied to a highly non-linear, gas-based heavy oil recovery process controlled by the gas temperature with the state depending non-linearly on time and two spatial directions inside a moving boundary, and subject to pressure upsets. The results demonstrate that when the process has a pressure upset, the proposed strategy is able to determine control adjustments with negligible time delays and to navigate the process to the new optimal state.

scholarly journals Mitigation of torsional vibration in large mill drive train system using state feedback control method

2021 ◽  
Author(s):  
Ehsan Al-Nabi
Keyword(s):  
Feedback Control ◽  
Torsional Vibration ◽  
Rolling Mill ◽  
State Feedback ◽  
Control Method ◽  
Dynamic Performance ◽  
Experimental System ◽  
State Feedback Control ◽  
Linear Quadratic ◽  
Single Input Single Output

Torsional vibration limits the speed loop response of industrial drives and servo systems, deteriorating the transient response to speed commands and load disturbances. This thesis presents a damping method for torsional vibration produced by compliant components between the motor and the load in rolling mill applications. The proposed damping algorithm can solve the limitation of the classical damping approaches due to the large values of system time delay. The proposed algorithm is based on State Feedback Control (SFC) method with modified Linear Quadratic Gaussian (LQG) approach using a torque sensor as a feedback element. The result of modification is a low order single-input single-output compensator that mitigates the torsional vibration without affecting the speed loop. The verification of the design and the dynamic performance is accomplished by using time and frequency domain responses with real rolling mill system parameters. The performance of step commands, mitigation of torsional vibration and robustness to parameter variation is satisfied by using the proposed method. Also disturbance rejection performance is improved through load torque compensation. The experiment is performed on a 0.8 KW system with 24 Hz mechanical resonant frequency. Simulation and experimental results from the experimental system verify the proposed damping algorithm.

On Passive Implementation of Feedback Control Systems

1989 ◽  
Vol 111 (2) ◽  
pp. 339-342
Author(s):  
R. Shoureshi
Keyword(s):  
Feedback Control ◽  
Control Systems ◽  
State Feedback ◽  
Closed Loop ◽  
State Feedback Control ◽  
Closed Loop Control ◽  
Linear Quadratic ◽  
Loop Control ◽  
Feedback Control Systems ◽  
Linear Quadratic Regulators

Closed-loop control systems, especially linear quadratic regulators (LQR), require feedbacks of all states. This requirement may not be feasible for those systems which have limitations due to geometry, power, required sensors, size, and cost. To overcome such requirements a passive method for implementation of state feedback control systems is presented.

scholarly journals The Parameter Variation Problem in State Feedback Control Systems

1965 ◽  
Vol 87 (1) ◽  
pp. 120-124 ◽  
Author(s):  
W. R. Perkins ◽  
J. B. Cruz
Keyword(s):  
Feedback Control ◽  
State Feedback ◽  
Parameter Variation ◽  
Open Loop ◽  
State Feedback Control ◽  
Optimal Feedback Control ◽  
Variation Problem ◽  
Quadratic Performance ◽  
New Interpretation ◽  
Low Sensitivity

The plant-parameter variation problem in multivariable linear systems described by state-vector equations is formulated using a new sensitivity measure. This formulation involves a direct comparison of open-loop and state-feedback performance in the presence of parameter variations and provides a basis for guaranteeing the superiority of the feedback design. Results are obtained for both continuous and discrete multi-input, multi-output systems. Furthermore, it is shown for single-input, multi-output plants that a low-sensitivity design is also an optimal feedback-control design with respect to a quadratic performance index. This provides a new interpretation of a similar result previously obtained by Kalman.

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