OMS MAXnet, User Manual

Page: 21 / 67

TUNE THE SYSTEM GETTING STARTED
MAXnet User’s Manual 2-15
FIGURE 2-12
The KA variable is used when tuning torque controlled servos (current mode servo amplifiers.) This
is the acceleration feedforward coefficient. Systems with high inertial loads may require additional
torque during acceleration or deceleration to achieve optimum performance. KA determines how
closely the system follows the desired acceleration and deceleration portions of the motion profile.
Increasing this term reduces the following error occurring during acceleration and deceleration of the
system. Although, if KA is too large, instability may occur.
The values for KA range from 0 to 249.99.
FIGURE 2-13
The block diagram below describes the feedback loop that is taking place in the servo system:
Desired Step Response
Actual Step Response
Velocity Following Error
Desired Step Response
Actual Step Response
Acceleration/Deceleration Following
Error
PID Algorithm/
Amplifier
Motor and Encoder
Error (i.e. Position)
Input
FIGURE 2-14 FEEDBACK LOOP