SuperFlow AutoDyn, Руководство оператора

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Control Mode Parameters
SuperFlow Technologies Group 11-11
point. If the P-Gain is too high, the system could overshoot the set point. The system shows
instability by oscillating (alternately overshooting and undershooting the set point) or surging.
The oscillation (or surging) may slowly subside over time. If the P-Gain is too low, the system
will never be within the range where the I-Gain will start working (I-Gain threshold).
Consequently, the set point is never reached. When setting up the control system, it is better to
start on the low side (enter smaller gain numbers) and then increase the values slowly.
Suggested Adjustment Technique
First adjust the P-Gain parameter. When initially adjusting the P-Gain, SuperFlow
recommends setting all other parameters to 0. With the I-Gain at zero, the system will never
reach its set point, but the control channel (engine speed, throttle, vehicle speed, etc.) will
move toward the set point. The purpose of adjusting the P-Gain with the other parameters at
zero is to adjust the P-Gain so the system reacts reasonably quickly without exhibiting
instability. Observe the (engine or wheel) speed and the control valve position indicator
(where available) while the system is seeking the set point. Note how quickly the controller
responds and whether it overshoots and undershoots as it seeks to control to the set point.
The control system will not pull the engine (or wheel speed) all the way down to the selected
speed because the I-Gain and I-Threshold are not set up yet. On an engine dynamometer, the
engine speed may stabilize at 300 to 500 rpm above the set point.
Try a minimal value of P-Gain. Successively double it until step response improves. If you
notice high frequency (1-10 Hz) steady-state instability as a result of increasing P-Gain, use
half the current value of P-Gain. Since P-Gain may have other undesired effects on step
response, use the minimal amount necessary to improve step response.
Check for stability at a minimum of four different speed set points. If the system surges for 30
seconds or less and then settles down, that’s okay. This is corrected when D-Gain is adjusted.
11.5.5 I-Gain
I
term
= (Error * I
gain_value
)
Allowed values: any floating point value
Suggested Value Range
• 0.01 to 0.08 for engine dynos
• 0.01 to 1 for CycleDyn controlling to vehicle speed
• 0 to 2 for AutoDyn controlling to vehicle speed
• Suggested setup prior to adjustment: 0.01
What it Does
The purpose of the integrator is to integrate the error to zero. The I-Gain (Integrator Gain)
keeps increasing controller output until the desired set point is reached. It sets the gain
applied to the integrated error and controls how fast the system responds to set point changes.
This process is much like the operator of a manual dyno who observes the current speed and
keeps adding load, a little at a time, until the set point is reached. It helps minimize time-
average deadband errors. If the I-Gain is too low, the engine or vehicle speed will take a long
time to achieve its set point. If the I-Gain is too high, the system may overshoot excessively
and take a long time to settle down or may never stabilize at the set point.
Suggested Adjustment Technique
Start with the minimal suggested value of I-Gain. Increase I-Gain by successively doubling it
until the rise time of the closed-loop step response of speed or torque is approximately 1 to 3