The NTUA snake: Design, planar kinematics, and motion planning

A new kind of robotic mechanism is proposed to be used for inspection tasks in complex setups of industrial plants. We propose a multiarticulated snake-like mobile robot, with a body consisting of repeating modules, capable of both efficiently moving and reaching points inside complicated or unstructured areas, where human personnel cannot reach or work properly. An analysis of the basic design along with most of the component specifications is presented. This mechanical system is subject to nonholonomic constraints. The kinematic model for motion on-plane of the mobile robot is derived by taking into consideration these constraints. The nonholonomic motion planning is partially solved by converting the multiple-input system to a multiple-chain, single-generator chained form via state feedback and a coordinate transformation. Stabilization and trajectory tracking issues are also considered. We also consider the general case of the n-trailer (or n-module) robotic snake. Simulation results are provided for various test cases.