On the dynamic analysis of a novel snake robot: preliminary results

In recent years, modular robotics has become of great interest in the robotics community. Among them, snake robots are among the most flexible and versatile type of mobile robots, well-suited to a large number of applications, such as exploration and inspection tasks, participation to search and rescue missions etc. The present paper investigates the design of a novel snake robot, named Rese_Q01, currently being designed at Politecnico di Torino. In order to characterise the dynamic behaviour of the robot, a simple vehicle dynamics model is developed and basic simulations are carried out for a first implementation of a unit consisting of two modules. Preliminary results show the influence of the robot velocity on the trajectory curvature radius, as well as the effect of different ground/tire friction conditions. This analysis is the first step in order to develop effective control strategies for robot trajectories

Trajectory Tracking for Underwater Swimming Manipulators using a Super Twisting Algorithm

International audienceThe underwater swimming manipulator (USM) is a snake-like, multi-articulated, underwater robot equipped with thrusters. One of the main purposes of the USM is to act like an underwater floating base manipulator. As such, it is essential to achieve good station-keeping and trajectory tracking performance for the USM using the thrusters, while using the joints to attain a desired position and orientation of the head and tail of the USM. In this paper, we propose a sliding mode control (SMC) law, in particular the super-twisting algorithm with adaptive gains, for trajectory tracking of the USMs center of mass. A higher-order sliding mode observer is proposed for state estimation. Furthermore, we show ultimate boundedness of the tracking errors and perform a simulation study to verify the applicability of the proposed control law and show that it has better tracking performance than a linear PD-controller