Soft crawling robots have attracted substantial attention for their environmental adaptability and compliant locomotion. However, the scalability of many soft in-pipe robots to large diameters remains limited because their locomotion typically relies on multi-point contact with the pipe inner wall. To overcome this limitation, we propose SMART-PIPEBOT, a woodpecker-tail-inspired adhesion-driven soft pipeline climbing robot that achieves single-sidewall attachment and locomotion in large-diameter pipes while markedly reducing dependence on distributed wall support. SMART-PIPEBOT integrates an inflatable silicone bladder, vacuum sucker brackets, silicone vacuum suckers, a constraining layer, and an elastic tail-support frame. Experiments quantified how vacuum-sucker inclination (10°–50°) affects adhesion at 0.05 MPa and evaluated single-sidewall climbing performance in large-diameter pipes (170, 200, and 230 mm). The maximum mean adhesion force was 26.778 N at a 30° inclination. SMART-PIPEBOT achieves maximum climbing speeds of 16.93 mm/s horizontally and 12.63 mm/s vertically under dry conditions and maintains continuous locomotion on wet walls with mean speeds of 4 mm/s (23.6% of the dry horizontal) and 2 mm/s (15.7% of the dry vertical). Payload experiments further demonstrate a pronounced improvement in effective load capacity when inspection equipment is mounted at the rear rather than the front, enabling a twofold increase in horizontal payload (100 g vs. 50 g) and a 1.5× increase in vertical payload (30 g vs. 20 g).
Lin et al. (Sun,) studied this question.