Sizing a motor is one of the most fundamental tasks in motion system design. It’s also the task most frequently performed incorrectly. The job of the motor is to move the load, so it’s easy to make the mistake of selecting it purely on whether it has sufficient torque and speed to match the application. That is an oversimplification that can introduce problems, however. The motor has to do more than simply move the load; it needs to position it how and when desired. Unfortunately, the interaction between the mechanism and the load can introduce resonances, leading to errors like overshoot and extended settling times.
In this white paper, we will discuss how the ratio of load inertia to motor inertia affects performance, how additional factors such as compliance come into play and how proper sizing, combined with auto tuning, can help deliver the best possible results.