Frequency-domain analysis of intermittent control

2009 ◽  
Vol 223 (5) ◽  
pp. 591-603 ◽  
Author(s):  
P J Gawthrop
Keyword(s):  
Frequency Domain ◽  
Balance Control ◽  
Design Method ◽  
Feedback System ◽  
Domain Analysis ◽  
Frequency Domain Analysis ◽  
Theoretical Explanation ◽  
Intermittent Control ◽  
Sampled Data ◽  
Data Feedback

Intermittent control is a feedback control design method that combines both continuous-time and discrete-time domains. A recent result shows that this form of intermittent control can be rewritten as a sampled-data feedback system with a particular vector generalized hold. This paper builds on this result to give, for the first time, a frequency-domain analysis of the closed-loop system containing an intermittent controller. This analysis is illustrated using two examples. The first example is related to the human balance control system and is thus physiologically relevant. The second example gives a theoretical explanation of the phenomenon of self-induced oscillations in intermittent control systems.

scholarly journals The Application of Disturbance-Observer-Based Control in Breath Pressure Control of Aviation Electronic Oxygen Regulator

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5189
Author(s):  
Rui Pan ◽  
Guiping Lin ◽  
Zhigao Shi ◽  
Yu Zeng ◽  
Xue Yang
Keyword(s):  
Frequency Domain ◽  
Disturbance Observer ◽  
Control Method ◽  
Design Method ◽  
Pressure Control ◽  
Domain Analysis ◽  
Frequency Domain Analysis ◽  
Sensitivity Function ◽  
Electronic Control System ◽  
Simulation And Experiment

The electronic oxygen regulator (EOR) is a new type of aviation oxygen equipment which uses electronic servo control technology to control breathing gas pressure. In this paper, the control method of EOR was studied, and the dynamic model of the aviation oxygen system was established. A disturbance-observer-based controller (DOBC) was designed by the backstepping method to achieve the goal of stable and fast breath pressure control. The sensitivity function was proposed to describe the effect of inspiratory flow on breath pressure. Combined with the frequency domain analysis of the input sensitivity function, the parameters of the DOBC were analyzed and designed. Simulation and experiment studies were carried out to examine the control performance of DOBC in respiratory resistance and positive pressurization process under the influence of noise and time delay in the discrete electronic control system, which could meet the aviation physiology requirements. The research results not only verified the rationality of the application of DOBC in the breath control of EOR, but also proved the effectiveness of the control parameters design method according to the frequency domain analysis, which provided an important design basis for the subsequent study of EOR.

scholarly journals Analysis of Three-Phase Wye-Delta Connected LLC

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3606
Author(s):  
Jing-Yuan Lin ◽  
Chuan-Ting Chen ◽  
Kuan-Hung Chen ◽  
Yi-Feng Lin
Keyword(s):  
Frequency Domain ◽  
Time Domain ◽  
Operation Time ◽  
Time Domain Analysis ◽  
Domain Analysis ◽  
Frequency Domain Analysis ◽  
Complete Analysis ◽  
Plane Analysis ◽  
Analysis Methods ◽  
Three Phase

Three-phase wye–delta LLC topology is suitable for voltage step down and high output current, and has been used in the industry for some time, e.g., for server power and EV charger. However, no comprehensive circuit analysis has been performed for three-phase wye–delta LLC. This paper provides complete analysis methods for three-phase wye–delta LLC. The analysis methods include circuit operation, time domain analysis, frequency domain analysis, and state–plane analysis. Circuit operation helps determine the circuit composition and operation sequence. Time domain analysis helps understand the detail operation, equivalent circuit model, and circuit equation. Frequency domain analysis helps obtain the curve of the transfer function and assists in circuit design. State–plane analysis is used for optimal trajectory control (OTC). These analyses not only can calculate the voltage/current stress, but can also help design three-phase wye-delta connected LLC and provide the OTC control reference. In addition, this paper uses PSIM simulation to verify the correctness of analysis. At the end, a 5-kW three-phase wye–delta LLC prototype is realized. The specification of the prototype is a DC input voltage of 380 V and output voltage/current of 48 V/105 A. The peak efficiency is 96.57%.

scholarly journals Amplitude Design of Perturbation Signal in Frequency-Domain Analysis of Grid-Connected Systems

2020 ◽  
Vol 53 (2) ◽  
pp. 13161-13166
Author(s):  
Henrik Alenius ◽  
Roni Luhtala ◽  
Tomi Roinila
Keyword(s):  
Frequency Domain ◽  
Domain Analysis ◽  
Frequency Domain Analysis
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