Digitalization of an Indoor-Positioning Lab Using a Mobile Robot and IIoT Integration

Abstract

Industry 4.0, the Industrial Internet of Things (IIoT) as well as Smart Lo gistics depend on locating mobile assets. In contrast to outdoor locating, GPS is not reliable for indoor positioning. Instead, different real-time loca ting systems (RTLS) are used in industries for indoor locating when there is no chance of obtaining GPS-satellite signals. Students in engineering disci plines should know about the chances offered by and the limits of RTLS, for example through corresponding lab experiments. However, measuring the accuracy of RTLS is a time-consuming task. Our goal is to provide a remote RTLS-accuracy measurement experiment by digitalizing and automating the whole process.This paper discusses adding remote experiment service to this lab, thus providing access to the lab infrastructure anytime and anywhere. A mobile robot was used to move an ultra-wideband (UWB) transponder and expo se it to the RTLS measurement infrastructure. By optimizing the routing algorithm of a mobile robot, the required accuracy and appropriate safety features were justified and the accuracy of the robot reached 2 cm. It also passed all the static and dynamic obstacles with acceptable safety thanks to inbuilt sensors. The remote operation was also done in an IoT environment by implementing the MQTT data transfer protocol. For remote users to be able to operate our RTLS system via MQTT, we developed a software program. When running this program, our DigiLab4U Laboratory Manage ment System (LabMS) is able to send commands to the RTLS system and receive positioning measurements of a mobile object (in our case RTLS tag) via MQTT messages. Thus, the real route and the measured route can be compared and the difference can be analyzed by students remotely.