Flow Rate Control System Proportional Only Controller April 2, 2006 U.T.C. Engineering 329
Yellow Team Jimy George Jeff Lawrence Taylor Murphy Jennifer Potter
Outline Flow System Background Previous Work Proportional Control Modeling Results Conclusions
Flow System Setup
Block Diagram
Steady State Operation
SSOC
Step Response Results K (lb/min/%) =0.26 τ (sec) =0.46 t 0 (sec) =0.42
Frequency Response Experiment
Bode Plots Kcu (%/(lb/min) =10.00 K ((lb/min)/%) =0.24 τ (sec) =0.27 t 0 (sec) =0.35 m (order) =1.14 fu (Hz) =0.95
Model Bode Plot K (lb/min/%) =0.22 t0 (sec) =0.35 Tau (sec)=0.25 f u =0.95
Model Bode Plot K (lb/min/%) =0.22 t0 (sec) =0.35 Tau (sec)=0.25 K cu =10
FOPDT Parameters K = 0.24 (lb/min)/% τ = 0.28 sec t 0 = 0.4 sec
Closed Loop Transfer Function
Root Locus Parameters K CD =0.08 K QD =6.6 K CU =10 f u =1.24 *all units for K are % / (lb/min)
ζ Locations Response to Step Change in Set PointSymbolAverage Critical DampingK CD /500th DecayK C /10 DecayK C Quarter DecayK QD 6.6 UltimateK CU 10
Results From Root Locus Ultimate Quarter Decay Critically Damped Underdamped Overdamped Kc = 10 Kc = 6.6 Kc = < Kc < 10 0 < Kc < 0.08 *all units are % / (lb/min)
Predicted Ultimate Frequency and Ultimate Gain Bode PlotLuyben Method Routh Method Direct Substitution K CU = 10% / (lb/min) K CU = 9.6% / (lb/min) K CU = 10% / (lb/min) F u =0.87 HzF u =0.67 Hzn/aF u = 1.24 Hz
Model Results for K CD Offset Offset = 4.9 lb/min Decay Ratio = 0 Settling Time = 0.8 s K CD = 0.10% / (lb/min) Set Point Output Settling Time
Model Results for K QD Offset Offset = 1.9 lb/min Decay Ratio = 0.25 Settling Time = 3.9 s K QD = 6.6%/ (lb/min) Settling Time Set Point Output
Model Results for K CU Offset = 1 lb/min Decay Ratio = 1 Settling Time = never K CU = 10%/ (lb/min) Output Set Point Offset
Proportional Only Model Results K C (%*min/lb)Offset (lb/min) Critical Damping /500th Decay /10 Decay Quarter Decay Ultimate101.5
Experimental Results for K CD Offset = 4.9 lb/min Decay Ratio = 0 Settling Time = 0.8 s K CD = 0.10% / (lb/min) Settling Time Offset
Experimental Results for K QD Offset = 2.4 lb/min Decay Ratio = 0.25 Settling Time = 4.5 s K QD = 0.10% / (lb/min) Offset Settling Time
Experimental Results for K CU Offset = 1.2 lb/min Decay Ratio = 1 Settling Time = never K CD = 10% / (lb/min) Offset
Proportional Only Experimental Results K C (%*min/lb)Offset (lb/min) Critical Damping /500th Decay /10 Decay Quarter Decay Ultimate101.2
Comparison of Results Critical Damping 1/500th Decay 1/10th Decay 1/4th Decay Ultimate Root Locus P-Only Model P-Only Experimental
Conclusion For Kc needed Overdamped0 < Kc < 0.10 Critically DampedKc = 0.10 Underdamped0.10< Kc < 10 Quarter Decay Kc = 5.0