The SDQ-based Message Estimator for Motion NCS

Abstract

The limitation of network bandwidth leads to data dropout of communication which degrades performance of NCS. For motion control system implemented with NCS, the missing interpolation messages will cause motion error and it can be compensated by applying the message estimator. However, the distribution of the missing data will be more relevant to motion accuracy in NCS even with the same dropout rate. This paper proposes a novel performance index, the short-window dropout quantities (SDQ) which is an estimation of both the data dropout rate and the messing message distribution, for the motion NCS. Furthermore, based on the estimation of SDQ. the intelligent motion message estimator (IMM) is proposed in this paper to effectively compensate for data dropout effect. Finally, simulation results of a multi-axis motion NCS indicate that the present IMM significantly improves motion contouring accuracy compared with the 1-delay estimator or the Taylor estimator.