A reliable communication and localization method for gas pipeline robot chain based on RSSI theory

Due to the huge microwave attenuation in small steel gas pipelines, the wireless in-pipe robots are unable to complete the inspection and maintenance in long distance. In this research, an approach of a reliable communication and localization method based on Received Signal Strength Indication (RSSI) theory and ultrasonic measurement for gas pipeline robot chain is proposed. Without any GPS modules in the pipe, the robots are able to measure and calculate a certain distance from the adjacent one by detecting and estimating the received wireless signal strength. Such approach enables the all members among the robot chain to cooperate and coordinate, and finally complete the pipeline inspection and maintenance. In addition, this paper describes a 'leader-follower' control approach in pipe to support the RSSI-based communication. The leader robot is responsible for the task of whole pipe inspection with wireless remote control by operator, and the follower robots act as the wireless 'signal relay station' for communication. Finally, such pipe robot chain cooperate and coordinate together, so that they are able to complete the inspection successfully. We evaluate the performance of the proposed method by using virtual reality simulation. The simulation result indicated that the proposed method could realize the reliable wireless communication and localization for the pipeline robots.