The primary purpose of the AC servo system is to precisely control the motion
of the load. The most fundamental considerations in selecting the servo system
are "reflected" load inertia, servo system maximum speed requirement, servo
system continuous torque requirement, and servo system peak torque requirement.

In a retrofit application, select the largest torque SureServo™ system that most
closely matches these parameters for the system being replaced.

In a new application, these parameters should be determined through calculation
and/or measurement. The following considerations should be followed in order to
select the proper SureServo™ system:

The inertia of everything attached to the servo motor driveshaft needs to be
considered and the total "reflected" inertia needs to be determined. This means
that all elements of any mechanical transmission and load inertia need to be
translated into an equivalent inertia as if attached directly to the motor
driveshaft. The ratio of "reflected" load inertia to motor inertia needs to be
carefully considered when selecting the servo system.

In general, applications that need high response or bandwidth will benefit from
keeping the ratio of load inertia to motor inertia as low as possible and ideally
under 10:1. Systems with ratios as high as 200:1 can be realized but
corresponding lower bandwidth or responsiveness must be accepted. The servo
response including the attached load inertia is determined by the servo tuning.

SureServo™ systems may be tuned manually, adaptively with measurement of the
load inertia, or set with default tuning based on a programmed value of load
inertia.

With knowledge of the motion profile and any mechanical transmission between
the motor and load, calculations can be made to determine the required servo
motor continuous torque, peak torque, and maximum motor speed.

The required amount of continuous torque must fall inside the continuous
operating region of the system torque-speed curve (you can check the continuous
torque at the average speed of the motion profile). The required amount of peak
torque must also fall within the servo system's intermittent operating region of the
system torque-speed curve (you need to check this value at the required
maximum speed).