Locomotion analysis of a pantograph-based adaptive wall-pressing in-pipe robot with a slider-crank drive and overrunning clutches

The paper addresses the locomotion analysis of a pantograph-based adaptive wall-pressing in-pipe robot with a slider-crank drive and overrunning clutches. A reduced kinematic scheme is developed using the axial coordinates of two traction modules and the crank angle as the main variables. In contrast to rigidly coupled designs, the pusher acts on one module through a compliant flat spring-damper element, which enables smoother force transmission and more realistic switching transients. On this basis, a hybrid dynamic model is formulated by combining the drive force, friction-limited clutch reactions, rolling resistance, and the axial component of gravity. Simulations are carried out for horizontal, inclined, and vertical pipelines. The obtained results show stable one-way locomotion in all considered cases, while the motion efficiency decreases with increasing inclination. The proposed concept is effective for adaptive in-pipe locomotion, although vertical climbing requires further optimization of the preload and damping parameters.