We specialize in legacy Indramat motion control components. Chances are, if you use Indramat motion control, you’ve thought about testing them at some point. It might have been when you stumbled into a cabinet and opened it to find a servo older than yourself. Is this thing still performing as it should? you might have wondered.
You can test those components.
Disturbance rejection and profile tracking are the most popular approaches to use when testing motion control for performance, since they cover the broadest range of applications. Disturbance rejection testing measures the motion controller’s ability to adapt to external disturbances. Initially, a load torque will be applied to the system, held for a brief period, and then released. From that point, the response of the controller is measured by the variables of maximum speed and settling time, which is the amount of time between when the disturbance occurs and when the speed returns to stable band around the target speed. Overly tuned controllers will produce longer settling times due to their tendency to very gradually decease oscillation around the target speed before finally settling.
Profile tracking, on the other hand, uses the metrics of maximum speed error and absolute error to measure how well a motion controller follows a changing target speed. Especially for motors that are subject to multiple speed changes, a lack of performance can lead to wasted power and materials. Maximum speed error testing will measure how much a motion controller overshoots when changing speeds. A poorly tuned controller will result in overshooting the target speed while also taking longer to recover. On the other hand, a properly tuned controller will produce minimal overshooting and will smoothly return to the goal speed.
Absolute average error
Now the absolute average error solely measures the average amount of the absolute values of all instantaneous speed errors across the entire test. An over-tuned motion controller will result in a higher absolute average error due to the constant oscillation occurring throughout the test. Similarly, an under-tuned controller will also result in a higher absolute average due to the fact that the actual speed would constantly be falling behind the originally commanded motor speed.
Unhappy with the performance of your Indramat motion control? Just turn to your Indramat tuning expert — no, you won’t have one of those. The famous Indramat Personality Modules were designed to eliminate tuning. That doesn’t mean that tuning is impossible, just that it is done rarely enough that you probably don’t have anyone around who has ever done it before.
It’s also possible that tuning isn’t really the issue. Heat, dirt, worn cables, and many other things can affect the performance of your motion control. Give us a call if performance is a concern with your Indramat and Indradrive components. We offer phone and field support, emergency replacement components, and factory repair.