Speed analysis for three driving modules of an in-pipe inspection robots for passing through bent pipes

To enable an in-pipe inspection robot with three driving modules to pass through bent pipes, the speed of each module needs to be calculated for steering. A simple method for finding this speed is based on kinematics (the relationship between the modules´ speeds and the robot´s target motion). However, the robot´s target motion in a bent pipe is not yet clarified and previous studies have only considered the case where the robot is completely inside the bent pipe. In this paper, the transition of the robot´s speeds during the whole process - moving through a bent pipe from one straight pipe to another - is analyzed.