A Novel Deformable Serial Pipeline Inspection Robots: Design, Modeling and Experimentation

In response to the urgent demands for daily maintenance and inspection of oil and gas pipelines, a novel modular pipeline inspection robot named RoboChain-I, featuring adaptive deformation capabilities, was proposed herein. Unlike most wheel-based pipeline robots, the robot adopted a cell-inspired modular biomimetic design with more flexible joint redundant rotational degrees of freedom (DOF), allowing the robot to actively deform in response to pipelines with varying shapes and diameters. Each module was equipped with dual-wheel independent drive, and a pair of pitch and yaw actuation mechanisms were installed at the front and rear. The modules were connected by passive elastic damping support structures or controllable electromagnetic adhesion-separation rigid structures, which improved the robot's ability to navigate complex pipelines and adapt to various environments. The forces acting on the robots during their motions inside the pipeline were modeled, and kinematics simulations were conducted using Adams. The selection of design parameters for the model was validated accordingly. A comprehensive series of experiments were conducted to evaluate RoboChain-I's performance, including terrestrial locomotion, straight pipe traversal, elbow pipe navigation, diameter-varying pipeline adaptation, and active mother-child separation. Experimental results validate the robot's effectiveness and reliability in performing inspection tasks within complex three-dimensional pipeline networks with diameters ranging from 175–440mm, demonstrating maximum velocities of 0.87m/s on flat surfaces and 0.4m/s within pipelines.