Parker EME
Setting up Compax3
192-120103 N13 C3I20T11 / C3I32T11 December 2010
279
disturbances (signal to noise ratio) increases with a rising frequency. The value as
well as the phase response of the displayed frequency response are "disturbed" at
the same intensity, this shows, that disturbances are the reason.
The value response consists basically of a straight, which declines with a slope of -
20dB/decade (-20dB/decade => per tenfold increase of the frequency, the value
decreases also by factor ten.
The phase response remains however almost constantly at -90° over a relatively
large range.
In control technology, this is called integrating behavior (I-behavior).
the I-behavior can be explained as follows.
The measured current is proportional to the motor force and thus also to the
acceleration of the driven mass. As the velocity is calculated from the integrated
acceleration, the measured system looks as follows:
f: disturbance torque
Kt
2*Pi*J
1
velocity controlled
system
Input value is the current actual value, output value is the velocity actual value
Resonance points and their causes
In this chapter you can read about:
Rotary two mass system ................................................................................................ 280
Linear two mass system ................................................................................................ 280
Toothed belt drive as two mass system ......................................................................... 281
Mechanical system with a resonance point
fARes: Anti resonance frequency
fRes: Resonance frequency
The displayed change of the frequency response (resonance point), has its cause
in a so-called two mass system (caused by the elastic coupling of two masses).
As, upon closer examination, each mechanic coupling shows a certain elasticity, it
is no the question if there is a resonance point, but at which frequency it is and how
well it is attenuated.
Hint
