Beyond Traversing in a Thin Pipe: Self-Sensing Odometry of a Pipeline Robot Driven by High-Frequency Dielectric Elastomer Actuators

In this paper, we propose an earthworm-inspired miniature pipeline robot capable of self-sensing odometry. The robot features a dielectric elastomer actuator as its elongation body and two specially designed passive anchors to achieve unidirectional motion without slipping. The odometry was achieved through the self-sensing scheme of DEAs and the summation of all step sizes over a period. The careful implementation of the self-sensing method resulted in a small sensing resolution of 0.05 mm at a high actuation frequency of 20 Hz for a cylindrical DEA. Finally, the robot obtained a self-sensing odometry in a pipe, showing good consistency with the ground truth. This work paves a new way for a miniature in-pipe robot to sense its own state without additional sensors to save space and power.