Estimating Wireless Link Quality using Multiple Remote Sensors for Wireless Control of AGV in a Factory

In recent days, various types of wireless communication-based equipment such as Automated Guided Vehicles (AGV) have been used to achieve enhancement of productivity and factory automation. Wireless communication networks are promising for a flexible factory where frequent reconfiguration occurs whereas communication quality and reliability may be the issues for their utilization. Our goal is that the spectrum management system monitors the state of the radio link quality and takes measures to avoid the failure of AGV communication before it occurs. This study showed the results of applying the estimation method of communication quality to the sensing results before the communication starts. We verified a method to determine the best-quality Access Points (APs) in advance by using a group of sensors, located in the space near and around the AP and AGV communication locations, to monitor spectrum usage and predict the communication quality of the links between the APs and the AGV. Experiment results confirmed that packet retransmission rates could be reduced over 35% by using the proposed method of selecting best AP instead of the common method based on largest signal strength.