Implementation alternatives for dual rate control systems with command shaping

A practical architecture for implementing motion control on complex machines is to generate the desired trajectory for all axes on a central computer (PC) at a modest sampling rate, and transmit the desired trajectory to individual axis controllers. This local controller closes an inner feedback loop at a higher sampling rate. If command shaping in the form of Optimal Arbitrary Time-delay (OAT) filtering is to be employed in these architectures to reduce vibration, it can be applied at the central computer or at the axis controller. This paper analyzes these alternatives and how they can be implemented.