Design Properties That Affect Controller Gain and Available Bandwidth of Non-Minimum Phase Membrane Humidifiers

2010 ◽  
Author(s):  
John F. Hall ◽  
Christine A. Mecklenborg ◽  
Dongmei Chen
Keyword(s):  
Membrane Properties ◽  
Minimum Phase ◽  
Available Bandwidth ◽  
Vapor Transfer ◽  
Control Gain ◽  
Controller Gain ◽  
The Impact ◽  
Competing Dynamics ◽  
Water Vapor Transfer ◽  
Zero Location

The water vapor transfer across a membrane exhibits non-minimum phase behavior. This paper shows that the competing dynamics of heat and mass transfer cause the membrane humidifier to have a non-minimum phase zero. Even though the non-minimum phase zero exists in the disturbance-output loop, it will limit the feedback controller gain because the disturbance-output loop is coupled with the input-output loop. The membrane properties and heat transfer parameters affect the non-minimum phase zero location. The impact on available feedback control gain and system bandwidth is analyzed in relation to changes of the non-minimum phase zero during hardware design.

The Effects of Membrane Properties and Structural Parameters on the Non-Minimum Phase Behavior of the PEM Fuel Cell Humidification System

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
John F. Hall ◽  
Christine A. Mecklenborg ◽  
Clay S. Hearn ◽  
Dongmei Chen
Keyword(s):  
Fuel Cell ◽  
Phase Behavior ◽  
Material Property ◽  
Coupling Effect ◽  
Structural Parameters ◽  
Pem Fuel Cell ◽  
Membrane Properties ◽  
Minimum Phase ◽  
Vapor Transfer ◽  
Channel Plate

The water vapor transfer across a Nafion® membrane exhibits an undesired non-minimum phase behavior. This paper will show that even in the disturbance-to-output loop, the non-minimum phase zero adversely affects the feedback controller design because of the coupling effect between the disturbance-to-output and the input-to-output loops. The non-minimum phase zero location is influenced by the channel plate structure and the membrane material property. The structural parameters examined in this research include channel plate dimensions and heat transfer coefficients. The membrane properties studied include membrane vapor transfer properties described in the Arrhenius’ equation. A governing equation to link the non-minimum phase zero and the parameters is developed in this paper. This equation shows that the non-minimum phase zero arises from the competing heat and mass transfer dynamics, and is determined by the structural parameters and membrane properties. A sensitivity study is presented and shows that structural and material property optimization can be used with the control system design to mitigate the non-minimum phase behavior in the PEM fuel cell humidification system.

scholarly journals Effect of hot calendering on physical properties and water vapor transfer resistance of bacterial cellulose films

2016 ◽  
Vol 51 (21) ◽  
pp. 9562-9572 ◽  
Author(s):  
V. L. D. Costa ◽  
A. P. Costa ◽  
M. E. Amaral ◽  
C. Oliveira ◽  
M. Gama ◽  
...  
Keyword(s):  
Water Vapor ◽  
Physical Properties ◽  
Bacterial Cellulose ◽  
Transfer Resistance ◽  
Cellulose Films ◽  
Vapor Transfer ◽  
Water Vapor Transfer

Accommodation of Multi-Shaft Gas Turbine Switching Control Gain Tuning Problem to IGV Position

2021 ◽  
Author(s):  
Yujia Ma ◽  
Liu Jinfu ◽  
Linhai Zhu ◽  
Qi Li ◽  
Huanpeng Liu ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Guide Vane ◽  
Optimization Procedure ◽  
Switching Control ◽  
Inlet Guide Vane ◽  
Multi Objective ◽  
Control Gain ◽  
Controller Gain ◽  
Compressor Inlet ◽  
Comprehensive Indicator

Abstract This article aims to discuss the influence of compressor Inlet Guide Vane (IGV) position on gas turbine switching control system gain tuning problem. The distinction between IGV and normally reckoned working conditions is differentiated, and an improved double-layer LPV model is proposed to estimate the protected parameters under various IGV positions. Controller gain tuning is conducted with single and multi-objective intellectual optimization algorithms. Simulation results reveal that normally used multi-objective optimization procedure is unnecessary and time-consuming. While with the comprehensive indicator introduced in this paper, the calculation burden can be greatly eased. This improvement is especially advantageous when tuning work is carried out under multiple IGV positions.

A Survey of Dynamic Bandwidth Assignment Schemes for TDM-Based Passive Optical Network

2020 ◽  
Vol 41 (3) ◽  
pp. 279-293 ◽  
Author(s):  
Rizwan Aslam Butt ◽  
M. Waqar Ashraf ◽  
M Faheem ◽  
Sevia M Idrus
Keyword(s):  
Multiple Access ◽  
Optical Network ◽  
Utilization Efficiency ◽  
Passive Optical Network ◽  
Bandwidth Utilization ◽  
Available Bandwidth ◽  
Dynamic Bandwidth Assignment ◽  
Time Division ◽  
Dynamic Bandwidth ◽  
The Impact

AbstractIn time division, multiple access (TDMA)-based passive optical network (PONs), a dynamic bandwidth assignment (DBA) is necessary for efficient utilization of the available bandwidth of the upstream link. An efficient DBA scheme can improve the upstream performance of a traffic class of an ONU in two ways. First, it can increase the bandwidth assignment to it by efficiently utilizing the available bandwidth. Secondly, it can reduce the channel and frame idle time by increasing the polling frequency and by assigning extra surplus bandwidth not used by the other ONUs. Many DBA schemes have been reported for both ITU PONs (GPON and XGPON) and IEEE PONs (EPON and 10 G EPON). In this study, we explain the impact of DBA scheme on the upstream performance of PON and then do a thorough survey of both PON standards, categorize the DBA schemes and review them critically. Based on the literature review we also give our opinion on the most suitable DBA scheme for both type PONs on the basis of upstream delays, frame loss and bandwidth utilization efficiency.

scholarly journals Heat and Water Vapor Transfer between Atmosphere and Pavement Surface Under Dry, Wet, Ice Plate and Packed Snow State

2006 ◽  
Vol 22 (3) ◽  
pp. 220-228 ◽  
Author(s):  
Akihiro Fujimoto ◽  
Hiroshi Watanabe ◽  
Teruyuki Fukuhara ◽  
Takeshi Sato ◽  
Masaki Nemoto ◽  
...  
Keyword(s):  
Water Vapor ◽  
Pavement Surface ◽  
Vapor Transfer ◽  
Water Vapor Transfer

EFFECTIVE DYNAMIC STIFFNESS MODEL AND ITS EFFECTS ON ROBOT SAFETY AND PERFORMANCE

2013 ◽  
Vol 37 (3) ◽  
pp. 395-403
Author(s):  
Dongjun Shin ◽  
Zhan Fan Quek
Keyword(s):  
Dynamic Stiffness ◽  
Joint Stiffness ◽  
Optimization Strategy ◽  
Design Guideline ◽  
Controller Gain ◽  
Stiffness Model ◽  
Effective Dynamic ◽  
Stiffness Characteristics ◽  
And Performance ◽  
The Impact

Due to the limited control bandwidth of pneumatic artificial muscles, joint stiffness characteristics and their effects on safety and performance of human-friendly robots should be considered in the frequency domain. This paper introduces the concept of effective dynamic stiffness and validates its model with the Stanford Safety Robot. Experimental results show that the dynamic stiffness demonstrates limited effects on the impact acceleration given the same impact velocity and controller gain, whereas it significantly affects control performance of position tracking due to pressure-induced non-linearities. A stiffness optimization strategy for safety and performance is discussed as a design guideline of human-friendly robots.

Fluid Tonicity Affects Peritoneal Characteristics Derived by 3-PORE Model

2019 ◽  
Vol 39 (3) ◽  
pp. 243-251 ◽  
Author(s):  
Joanna Stachowska-Pietka ◽  
Jan Poleszczuk ◽  
Josep Teixido-Planas ◽  
Josep Bonet-Sol ◽  
Maria I. Troya-Saborido ◽  
...  
Keyword(s):  
Model Fitting ◽  
Hydraulic Conductance ◽  
Membrane Properties ◽  
Patient Specific ◽  
Model Parameters ◽  
Peritoneal Membrane ◽  
Substantial Impact ◽  
Pore Model ◽  
Using Data ◽  
The Impact

Background It is typically assumed that within short time-frames, patient-specific peritoneal membrane characteristics are constant and do not depend on the initial fluid tonicity and dwell duration. The aim of this study was to check whether this assumption holds when membrane properties are estimated using the 3-pore model (3PM). Methods Thirty-two stable peritoneal dialysis (PD) patients underwent 3 8-hour peritoneal equilibration tests (PETs) with different glucose-based solutions (1.36%, 2.27%, and 3.86%). Temporary drainage was performed at 1 and 4 hours. Glucose, urea, creatinine, sodium, and phosphate concentrations were measured in dialysate and blood samples. Three-pore model parameters were estimated for each patient and each 8-hour PET separately. In addition, model parameters were estimated using data truncated to the initial 4 hours of peritoneal dwell. Results In all cases, model-estimated parameter values were within previously reported ranges. The peritoneal absorption (PA) and diffusive permeability for all solutes except sodium increased with fluid tonicity, with about 18% increase when switching from glucose 2.27% to 3.86%. Glucose peritoneal reflection coefficient and osmotic conductance (OsmCond), and fraction of hydraulic conductance for ultrasmall pores decreased with fluid tonicity (over 40% when switching from glucose 1.36%). Model fitting to the truncated 4-hour data resulted in little change in the parameters, except for PA, peritoneal hydraulic conductance, and OsmCond, for which higher values for the 4-hour dwell were found. Conclusion Initial fluid tonicity has a substantial impact on the 3PM-estimated characteristics of the peritoneal membrane, whereas the impact of dwell duration was relatively small and possibly influenced by the change in the patient's activity.

scholarly journals Dynamic Simulation Modeling of Heat and Water Vapor Transfer in a Fluid-Roof Greenhouse.

2001 ◽  
Vol 57 (4) ◽  
pp. 169-182 ◽  
Author(s):  
Ahmed M. ABDEL-GHANY ◽  
Toyoki KOZAI ◽  
Nabil Y. ABDEL-SHAFI ◽  
Ibrahem S. TAHA ◽  
Ahmed S. HUZAYYIN
Keyword(s):  
Water Vapor ◽  
Dynamic Simulation ◽  
Simulation Modeling ◽  
Vapor Transfer ◽  
Water Vapor Transfer
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