Method for increasing the accuracy of synchronous control by compensating for network latency

Network-based control systems are becoming increasingly popular for industrial applications; however, in these systems, it is impossible to transmit a control command to multiple devices at the same time due to network latency. The network latency of each device varies depending on network topology, which makes synchronous control difficult. In order to address this problem, this paper proposes a synchronous control algorithm that can compensate for network latency-related variation in when each device receives a control command. The proposed algorithm can be used for various types of real-time Ethernet and fieldbuses. In this paper, the proposed algorithm is applied to Mechatrolink-III, a real-time Ethernet, in order to control a synchronous system. The accuracy of the synchronous control is improved significantly when applying the proposed algorithm.