scholarly journals Absolute Stability Condition Derivation for Position Closed-Loop System in Hydraulic Automatic Gauge Control

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 766 ◽  
Author(s):  
Zhu ◽  
Tang ◽  
Wang ◽  
Jiang ◽  
Zhao ◽  
...  
Keyword(s):  
Absolute Stability ◽  
Information Transfer ◽  
Closed Loop ◽  
Position Control ◽  
Block Diagram ◽  
Metallurgical Industry ◽  
Loop System ◽  
Transfer Model ◽  
Closed Loop System ◽  
Automatic Gauge Control

In the metallurgical industry, hydraulic automatic gauge control (HAGC) is a core mechanism for thickness control of plates used in the rolling process. The stability of the HAGC system’s kernel position closed-loop is key to ensuring a process with high precision, speed and reliability. However, the closed-loop position control system is typically nonlinear, and its stability is affected by several factors, making it difficult to analyze instability in the system. This paper describes in detail the functioning of the position closed-loop system. A mathematical model of each component was established using theoretical analysis. An incremental transfer model of the position closed-loop system was also derived by studying the connections between each component. In addition, based on the derived information transfer relationship, a transfer block diagram of disturbance quantity of the system was established. Furthermore, the Popov frequency criterion method was introduced to ascertain its absolute stability. The results indicate that the absolute stability conditions of the position closed-loop system are derived in two situations: when spool displacement is positive or negative. This study lays a theoretical foundation for research on the instability mechanism of an HAGC system.

scholarly journals Instability Condition Derivation for Hydraulic AGC System under Pressure Closed-Loop Control

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Yong Zhu ◽  
Guangpeng Li ◽  
Shengnan Tang ◽  
Wanlu Jiang ◽  
Pengfei Qian ◽  
...  
Keyword(s):  
Information Transfer ◽  
High Performance ◽  
Closed Loop ◽  
Block Diagram ◽  
Transfer Model ◽  
Closed Loop Control ◽  
Instability Mechanism ◽  
Instability Condition ◽  
Strip Rolling ◽  
Loop Control

In strip rolling, hydraulic automatic gauge control (HAGC) system is the key element to guarantee the precision of strip gauge. The stability of the kernel pressure closed loop (PCL) in the HAGC system plays an essential role in guaranteeing the rolling process with high performance. Nevertheless, there is some difficulty in exploring the instability mechanism of the HAGC system due to the fact that the PCL is a representative nonlinear closed-loop control system. In this work, for each component of the HAGC system, the mathematical model was established. And on the basis of the linking relation of various elements, we derived the incremental transfer model of the PCL system. Furthermore, in accordance with the deduced information transfer relation, the transfer block diagram of disturbing variable of the PCL system was obtained. Moreover, for the purpose of deriving the instability condition of the PCL system, the Popov frequency criterion was employed. The instability conditions of the HAGC system were obtained under PCL control. Furthermore, the derived instability conditions of the HAGC system were experimentally verified under various working conditions. The research results provide a fundamental foundation for studying the instability mechanism of the HAGC system.

End Point Position Control of Multi-Link Flexible Manipulators Using SDRE Method

2004 ◽  
Author(s):  
Jamil M. Renno ◽  
Woosoon Yim ◽  
Sahjendra N. Singh
Keyword(s):  
Equilibrium State ◽  
Closed Loop ◽  
Position Control ◽  
Loop System ◽  
Suboptimal Control ◽  
Flexible Manipulator ◽  
Flexible Manipulators ◽  
Closed Loop System ◽  
End Point ◽  
Elastic Modes

This paper treats end point regulation of multi-link light-weight flexible manipulators using the State Dependent Riccati Equation: SDRE method. It is well known that end point trajectory control using widely used feedback linearization techniques is not possible when the equilibrium state of the zero dynamics of the system is unstable or weakly stable. Furthermore, control saturation is a major problem in controlling nonlinear systems. In this paper, an optimal control problem is formulated for the derivation of control law with and without control constraints on the joint torques for a multi-link flexible manipulator and suboptimal control laws are designed using the SDRE method. For the purpose of control, pseudo joint angles and elastic modes of each link are regulated to their equilibrium values which correspond to the target end point. Weighting matrices in the quadratic performance index provide flexibility in shaping the pseudo angles and elastic modes trajectories. In the closed-loop system, the equilibrium state is asymptotically stable, and vibration is suppressed. Simulation results are presented for a two-link flexible manipulator, which show that in the closed-loop system, end point trajectory tracking is accomplished even with constraints on the control torque. Results also show that the transient characteristics of the pseudo angles and elastic modes can be easily shaped by the choice of the performance criterion.

Simulation of the effects of load on hydraulic servo actuators

SIMULATION ◽  
1969 ◽  
Vol 12 (3) ◽  
pp. 145-151 ◽  
Author(s):  
Myron Glickman
Keyword(s):  
Control System ◽  
Closed Loop ◽  
Block Diagram ◽  
System Simulation ◽  
Loop System ◽  
General Description ◽  
Control Loop ◽  
Closed Loop System ◽  
Servo Actuator ◽  
Hydraulic Servo

Control system analysts are frequently called upon to include a hydraulic servo actuator as part of the loop in a complex closed-loop system simulation. This article presents a general description of several common types of hydraulic servo actuators and several methods for inclusion of the effects of load on the simulation of the actuator in the control loop. These methods are pre sented in block diagram form and are suitable for inclu sion in a larger simulation loop. The block diagrams themselves may be somewhat condensed and modified before inclusion in a larger simulation, but are presented here with all the details shown explicitly for clarity.

Safety and Performance of the Omnipod®Hybrid Closed-Loop System in Adolescents with Type 1 Diabetes over Five Days Under Free-Living Conditions

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1376-P
Author(s):  
GREGORY P. FORLENZA ◽  
BRUCE BUCKINGHAM ◽  
JENNIFER SHERR ◽  
THOMAS A. PEYSER ◽  
JOON BOK LEE ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Closed Loop ◽  
Living Conditions ◽  
Loop System ◽  
Closed Loop System ◽  
Free Living ◽  
And Performance ◽  
Free Living Conditions

1066-P: Improvement in Time-in-Range (TIR) with Real-Life Use of Hybrid Closed-Loop System in Patients with Type 1 Diabetes (T1D)

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 1066-P
Author(s):  
HALIS K. AKTURK ◽  
DOMINIQUE A. GIORDANO ◽  
HAL JOSEPH ◽  
SATISH K. GARG ◽  
JANET K. SNELL-BERGEON
Keyword(s):  
Type 1 Diabetes ◽  
Closed Loop ◽  
Real Life ◽  
Loop System ◽  
Closed Loop System ◽  
Time In Range

Safety and Performance of the Omnipod® Hybrid Closed-Loop System in Adults with Type 1 Diabetes over Five Days Under Free-Living Conditions

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 207-OR
Author(s):  
BRUCE A. BUCKINGHAM ◽  
JENNIFER SHERR ◽  
GREGORY P. FORLENZA ◽  
THOMAS A. PEYSER ◽  
JOON BOK LEE ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Closed Loop ◽  
Living Conditions ◽  
Loop System ◽  
Closed Loop System ◽  
Free Living ◽  
And Performance ◽  
Free Living Conditions
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