A hybrid model of obstacle-aided snake robot locomotion

Abstract

Abstract-A snake can traverse cluttered and irregular environments by using irregularities around its body as pushpoints to aid the propulsion. This characteristic feature of biological snake locomotion, denoted obstacle-aided locomotion, is investigated for snake robot locomotion purposes in this paper. The paper presents a hybrid model of the dynamics of a planar snake robot interacting with obstacles in its environment. Obstacle contact forces are calculated by formulating and solving a linear complementarity problem (LCP). The existence and uniqueness properties of the state evolution of the hybrid model are investigated. Simulation results validate the hybrid modelling approach.

Modelling and Path Planning of Snake Robot in cluttered environment

“…The viscous friction model is similar to [5] instead of scheduling contacts we consider the whole body of the snake robot to be planar and in contact with ground. The body velocity of link i with respect to the head frame (link 0) is denoted as ξ0i and is computed using the differential mapping,…”

“…By good contacts we mean the set of contacts of the snake robot with the obstacles that help it propel forward and a super set of such sets gives the complete set of contacts that help the robot traverse completely through the cluttered path. In the previous works such as [4,5,6] the path chosen by the snake robot is completely dependent on the dynamics of the robot acted upon by the forces and the series of contact that lead the snake robot to traverse through the cluttered environment. But our idea here is to make the snake robot reach to a particular target point using the easiest path and avoid the path that difficult to follow or that are unfavourable for the snake robot to reach without losing its speed in between.…”

“…Liljebäck et al in [4] focus on modelling and control of obstacle-aided motion of snake robot for locomotion in forward direction. Also their further work [5][6][7] introduces different mathematical models to formulate and model the obstacle aided motion of the snake robot. The research done in [4][5][6][7] is quite helpful in dynamically planning the motion of the snake robots but the complexity of the models is quite high.…”

“…Also their further work [5][6][7] introduces different mathematical models to formulate and model the obstacle aided motion of the snake robot. The research done in [4][5][6][7] is quite helpful in dynamically planning the motion of the snake robots but the complexity of the models is quite high. In this paper we present a solution to this complex problem that is less challenging to implement and more efficient computationally.…”

Using kinesthetic input to overcome obstacles with snake robots

“…Previously, the primary developments in the science of locomotion for these and other snake robots have been in gaits, or cyclic joint inputs that locomote the robots over fairly steady state terrain [4], [5]. The existing work on obstacle-aided snake locomotion [6], [7] involves two-dimensional setups which Fig. 1: In the kinesthetic control approach, a user moves an input snake (often termed the "master" or a "dolly"), and the controlled "slave" robot moves accordingly.…”