A Highly Reliable Communication System for Internet of Robotic Things and Implementation in RT-Middleware With AMQP Communication Interfaces

Since the Internet of Robotic Things (IoRT) is composed of robots with actuators, interferences with the real-world activities are necessary, and safety is essential. In addition, some IoRT services may require bidirectional communication between multiple machines. One of the communication protocols that satisfy these requirements is AMQP, a broker architecture that emphasizes reliability and high functionality in communication. Therefore, using AMQP as the communication infrastructure between components in an IoRT system, it can contribute to improving the reliability of robot operations in IoRT and diversifying messaging between robots. To verify AMQP’s communication advantages, we have implemented the communication interface of AMQP in RT-Middleware, which is one of the robot middlewares, and have conducted performance and reliability tests on the effectiveness of RT-Middleware as a platform for constructing a reliable IoRT system. In the tests, we compared the communication performance of the platform with CORBA and MQTT communication interfaces implemented in RT-Middleware. The results show that although AMQP causes a small amount of latency compared to other communication interfaces, the distribution range of the latency is small, and relatively stable communication is performed. Furthermore, in the messaging quality test results, the data loss during communication by AMQP is almost a hundred times better than CORBA, and ten times better than MQTT, which mean that highly reliable messaging is possible. Based on this study’s findings, we conclude that AMQP should be fully used as a communication protocol for constructing IoRT systems.