Algorithm for optimising the position of the centre of mass of a pipeline inspection robot model while passing through fittings on inclined pipeline branches

This paper presents an algorithm for determining the optimal centre-of-mass (CoM) position and robot configuration, enabling stable passage through inclined pipeline branches with a minimal risk of jamming. The research aims to analyse the position of the robot's CoM during its passage through complex pipeline fittings, the corresponding robot configuration, the distribution of contact loads between the wheels and the pipeline wall, and the control of the robot joints. Furthermore, the stability of the robot at specific CoM positions is investigated. The simulation case study considers a conceptual two-section robot consisting of driving and driven modules, each equipped with three legs, two joints per leg, and rubber wheels in contact with the pipeline wall. The proposed approach is evaluated exclusively through numerical simulations of T- and Y-junction pipeline fittings with different pipeline slopes. The robot model, control algorithm, and CoM optimisation module were developed and implemented in MATLAB.