scholarly journals Open-loop and closed-loop flow control based on Van der Pol modeling

2017 ◽  
Vol 229 (1) ◽  
pp. 389-401
Author(s):  
Valentina Motta ◽  
Leonie Malzacher
Keyword(s):  
Flow Control ◽  
Closed Loop ◽  
Open Loop ◽  
Van Der Pol

Discrete Time Open-Loop and Closed-Loop Flow Control Based on Van der Pol Modeling

2016 ◽  
Author(s):  
Valentina Motta ◽  
Philippe Mouyon ◽  
Carsten Döll
Keyword(s):  
Flow Control ◽  
Discrete Time ◽  
Closed Loop ◽  
Open Loop ◽  
Van Der Pol

scholarly journals Design of Flow Control System with A Kickback Flow as A Manipulated Variable

Eksergi ◽  
2017 ◽  
Vol 14 (2) ◽  
pp. 23
Author(s):  
Yulius Deddy Hermawan
Keyword(s):  
Steady State ◽  
Flow Control ◽  
Liquid Flow ◽  
Stability Criterion ◽  
Closed Loop ◽  
Open Loop ◽  
Loop Model ◽  
Point Change ◽  
Controller Gain ◽  
Control Configuration

The open loop experiment of water flow dynamic in pipe has been done in laboratory. Pump was used to flow water in pipe. Part of liquid from discard of pump was recycled back to the suction of pump (kickback) and adjusted to control the liquid flow to the next process. The open loop laboratory experiment produced the steady state parameters; they were discard flowrate =16.6 [L/min], kickback flowrate =5.8 [L/min], and liquid flowrate to the next process =10.8 [L/min]. These steady state parameters were then used as the initial value for closed loop simulation with computer programming. This study has proposed the liquid flow control configuration by manipulating the kickback flow. Proportional Integral (PI) was proposed to control the flow and Routh-Hurwitz (RH) stability criterion was chosen to predict the range of the controller gain (Kc) that gives stable response. The closed loop model was solved analytically with Laplace method for both servo and regulatory problems. The set point change of flow and disturbance were made based on step function. The scilab software was used to do closed loop simulation. Based on RH stability criterion, the controller gain should be negative in order to give stable response. The closed loop simulation showed that by using controller gain Kc=–0.5 and integral time constant tI=0.3 [min], stable and fast response with Integral Absolute Error (IAE) near to zero (0,0022) could be achieved.

Enhancement of dynamic performance of wave energy converter by introducing a flow control

2022 ◽  
pp. 014233122110699
Author(s):  
Dazhou Geng ◽  
Qijuan Chen ◽  
Yang Zheng ◽  
Xuhui Yue ◽  
Donglin Yan
Keyword(s):  
Flow Control ◽  
Transient Process ◽  
Closed Loop ◽  
Control Method ◽  
Control Valve ◽  
Open Loop ◽  
Closed Loop Control ◽  
Flow Control Valve ◽  
Open Loop Control ◽  
Loop Control

The stabilization of power take-off (PTO) is imperative especially under circumstances of fluctuating input wave energy. In this paper, a flow control valve is introduced to optimize the transient process of the hydraulic PTO, which can contribute to a quicker adjustment and a stronger stability. Under variations of input power and load torque in transient process, an open-loop control method and a closed-loop control method are proposed as the opening law of the above valve, and the hydraulic motor speed, the pressure at the accumulator inlet and the generated power are chosen as indicators to examine the regulation performance. Then, the synergic effect of the flow control valve and the accumulator in the transient process is discussed. The effectiveness of the two presented control methods on the fluctuation suppression is respectively tested and compared in both regular wave and irregular wave situations via simulation. To validate the practical effectiveness of the proposed methods, field experiments are conducted. The results demonstrate that the open-loop control can only improve the damping ability of the hydraulic PTO in the speed raising stage, while the closed-loop control can improve the stability both in the speed raising stage and in the load increasing stage.

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.

Comparison of Dc-Dc SEPIC, CUK and Flyback Converters Based LED Drivers

2020 ◽  
pp. 99-107
Author(s):  
Erdal Sehirli
Keyword(s):  
Integrated Circuit ◽  
Closed Loop ◽  
Input Voltage ◽  
Open Loop ◽  
Current Sensor ◽  
Switching Frequency ◽  
Led Driver ◽  
Advantages And Disadvantages ◽  
Led Drivers ◽  
Conduction Mode

This paper presents the comparison of LED driver topologies that include SEPIC, CUK and FLYBACK DC-DC converters. Both topologies are designed for 8W power and operated in discontinuous conduction mode (DCM) with 88 kHz switching frequency. Furthermore, inductors of SEPIC and CUK converters are wounded as coupled. Applications are realized by using SG3524 integrated circuit for open loop and PIC16F877 microcontroller for closed loop. Besides, ACS712 current sensor used to limit maximum LED current for closed loop applications. Finally, SEPIC, CUK and FLYBACK DC-DC LED drivers are compared with respect to LED current, LED voltage, input voltage and current. Also, advantages and disadvantages of all topologies are concluded.

Aerodynamic Closed-Loop Flow Control of a Free Moving Airfoil (Invited)

2008 ◽  
Author(s):  
Ari Glezer ◽  
Anthony Calise
Keyword(s):  
Flow Control ◽  
Closed Loop

Vibration Reduction on Helicopter Rotors Using Open Loop Flow Control

2021 ◽  
Author(s):  
Ryan P. Patterson ◽  
Peretz P. Friedmann
Keyword(s):  
Flow Control ◽  
Vibration Reduction ◽  
Open Loop ◽  
Helicopter Rotors
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