Development of an inchworm-like soft pipe robot for detection

Pipe robots have been gradually applied to regularly detect drainage pipelines in building to ensure drainage system operating smoothly. However, mostly existing pipe robots hardly pass through various pipelines for insufficient flexibility of rigid mechanism and clumsy movement. Inspired by the soft limbs and efficient motion mode of inchworm, a soft pipe robot is developed to smoothly traverse these pipelines by reasonably optimizing modular actuators based on deformation analysis. By constructing a uniform mechanical model considering varying gravity load, the mechanical equilibrium relations during robot worming are established to accurately calculate inflating/deflating volume of actuators. Integrating inflating/deflating time calculating method for different working-state actuators, an efficient motion control workflow is developed to coordinately control each actuator to inflate/deflate orderly with the cooperation of control system. Experiment results show that the developed robot adopting proposed motion control workflow can move stably in horizontal, vertical, inclined, varying diameter and continuous curved pipelines.