BogieBot: A Climbing Robot in Cluttered Confined Space of Bogies with Ferrous Metal Surfaces

Proactive inspection is essential for prediction and prevention of rolling stock component failures. The conventional process for inspecting bogies under trains presents significant challenges for inspectors who need to visually check the tight and cluttered environment. We propose a miniature multi-link climbing robot, called BogieBot, that can be deployed inside the undercarriage areas of trains and other large vehicles for inspection and maintenance purposes. BogieBot can carry a visual sensor or manipulator on its main body. The novel compact design utilises six identical couple joints and two mechanically switchable magnetic grippers that together, empower multi-modal climbing and manipulation. The proposed mechanism is kinematically redundant, allowing the robot to perform self-motions in a tight space and manoeuvre around obstacles. The mechanism design and various analyses on the forward and inverse kinematic, work-space, and self-motions of BogieBot are presented. The robot is demonstrated to perform challenging navigation tasks in different scenarios involving simulated complex environments.