Page 135 - Servo Motors and Industrial Control Theory -

130 7 Electrohydraulic Servo Motors

With fifth-order transfer function, a numerical investigation was carried out. It
is not so important to give the exact model; instead, the purpose was to show that
when the system equations is solved and the controller parameters is adjusted, what
kind of response should be expected. The author has his own developed software to
calculate the roots of the characteristic equation and from there to obtain an exact
solution using partial fraction method. This was developed several years ago and it
is not recommended for reason of that there are standard commercial mathematical
program. The author has used the MathCad software in previous chapters to find the
roots of the characteristic equation. These are very important in design of servo mo-
tors. When the system is designed by a proper controller, then the transient response
can be obtained numerically by defining a simple loop and time step. The time step
for numerical integration must be chosen as to respect of higher natural frequency
present in the system.