moog伺服阀传递函数.pdf

: .
ables when performing measurements of
meters is given in Appendix I of this tech-
The difficulty in assuming an explicit servovalve dynamics. If such precautions
nical bulletin.
transfer function for electrohydraulic ser- are not taken, misleading and inaccurate
vovalves is that many design factors and Once a servovalve is built, the actual results may be obtained. Appendix II to
many operational and environmental var- dynamic response will vary somewhat this Bulletin describes the productionequipment presently used by Moog to
measure servovalve dynamic response.
Another difficulty in assigning simplified,
linear transfer functions to represent
servovalve response is that these valves are
highly complex devices that exhibit
high-order, nonlinear responses. If a first,
second, or even third-order transfer function
is selected to represent servovalve
dynamics, still only an approximation to
actual response is possible. Fortunately, for
most physical systems, the servovalve is not
the primary dynamic element, so it is only
necessary to represent valve response
throughout a relatively low frequency
spectrum. For instance, if a
servovalve-actuator is coupled to a load
which exhibits a 50 cps resonant frequency,
it is meaningful only to represent valve
dynamic response in the frequency range to
50 cps. Similarly, for lower response
physical systems, the contribution of valve
dynamics throughout a correspondingly
smaller frequency range need be
considered.