470 research outputs found
A Study on Sinus-Lifting Motion of a Snake Robot With Sequential Optimization of a Hybrid System
In this paper, we consider “sinus-lifting motion” of a living snake, in which a snake lifts up some parts of its body from the ground, and switches the lifted parts dynamically. It is not clear whether imitating the sinus-lifting motion is the best locomotion or not for a snake like robot. The aim of this paper is to propose an appropriate motion pattern to a snake like robot considering the optimality of the sinus-lifting motion. We introduce two physical parameters, constraint forces and energy efficiency, as cost functions to optimize and propose switching strategies for generating optimal motion patterns of a snake like robot
The kinematics of hyper-redundant robot locomotion
This paper considers the kinematics of hyper-redundant (or “serpentine”) robot locomotion over uneven solid terrain, and presents algorithms to implement a variety of “gaits”. The analysis and algorithms are based on a continuous backbone curve model which captures the robot's macroscopic geometry. Two classes of gaits, based on stationary waves and traveling waves of mechanism deformation, are introduced for hyper-redundant robots of both constant and variable length. We also illustrate how the locomotion algorithms can be used to plan the manipulation of objects which are grasped in a tentacle-like manner. Several of these gaits and the manipulation algorithm have been implemented on a 30 degree-of-freedom hyper-redundant robot. Experimental results are presented to demonstrate and validate these concepts and our modeling assumptions
Locomotion capabilities of a modular robot with eight pitch-yaw-connecting modules
This is an electronic version of the paper presented at the International Conference on Climbing and Walking Robots, held in 2006 on BrusselsIn this paper, a general classification of the
modular robots is proposed, based on their topology and
the type of connection between the modules. The loco-
motion capabilities of the sub-group of pitch-yaw con-
necting robots are analyzed. Five different gaits have
been implemented and tested on a real robot composed
of eight modules. One of them, rotating, has not been
previously achieved. All gaits are implemented using a
simple and elegant central pattern generator (CPG) ap-
proach that simplify the algorithms of the controlling
system
DETC2005-85130 CONTROL OF 3D SNAKE-LIKE LOCOMOTIVE MECHANISM BASED ON CONTINUUM MODELING
ABSTRACT An effective control method that achieves movement over a small ridge as an example of three-dimensional (3D) snake-like creeping locomotion is presented. The creeping robot is modeled as a continuum with zero thickness capable of generating bending moment at arbitrary points. Under a simplified contact condition, the optimal bending moment distribution in terms of a quadratic cost function of input can be obtained as a function of curvature by solving an isoperimetric problem. The solution is well suited to an articulated body consisting of finite number of links. The model is demonstrated through simulations and experiments using a prototype robot to be effective for traversing smooth 3D terrain
Anisotropic body compliance facilitates robotic sidewinding in complex environments
Sidewinding, a locomotion strategy characterized by the coordination of
lateral and vertical body undulations, is frequently observed in rattlesnakes
and has been successfully reconstructed by limbless robotic systems for
effective movement across diverse terrestrial terrains. However, the
integration of compliant mechanisms into sidewinding limbless robots remains
less explored, posing challenges for navigation in complex, rheologically
diverse environments. Inspired by a notable control simplification via
mechanical intelligence in lateral undulation, which offloads feedback control
to passive body mechanics and interactions with the environment, we present an
innovative design of a mechanically intelligent limbless robot for sidewinding.
This robot features a decentralized bilateral cable actuation system that
resembles organismal muscle actuation mechanisms. We develop a feedforward
controller that incorporates programmable body compliance into the sidewinding
gait template. Our experimental results highlight the emergence of mechanical
intelligence when the robot is equipped with an appropriate level of body
compliance. This allows the robot to 1) locomote more energetically
efficiently, as evidenced by a reduced cost of transport, and 2) navigate
through terrain heterogeneities, all achieved in an open-loop manner, without
the need for environmental awareness
Development of a novel locomotion algorithm for snake robot
A novel algorithm for snake robot locomotion is developed and analyzed in this paper. Serpentine is one of the renowned locomotion for snake robot in disaster recovery mission to overcome narrow space navigation. Several locomotion for snake navigation, such as concertina or rectilinear may be suitable for narrow spaces, but is highly inefficient if the same type of locomotion is used even in open spaces resulting friction reduction which make difficulties for snake movement. A novel locomotion algorithm has been proposed based on the modification of the multi-link snake robot, the modifications include alterations to the snake segments as well elements that mimic scales on the underside of the snake body. Snake robot can be able to navigate in the narrow space using this developed locomotion algorithm. The developed algorithm surmount the others locomotion limitation in narrow space navigation
Investigation of a novel type of locomotion for a snake robot suited for narrow spaces
In snake robot research, one of the most efficient forms of locomotion is the lateral undulation.
However, lateral undulation, also known as serpentine locomotion, is ill-suited for narrow spaces, as
the body of the snake must assume a certain amount of curvature to propel forward. Other types of
motion such as the concertina or rectilinear may be suitable for narrow spaces, but is highly inefficient
if the same type of locomotion is used even in open spaces. Though snakes naturally can interchange
between the use of serpentine and concertina movement depending on the environment, snake robots
based on lateral undulation to date are unable to function satisfactorily in narrow spaces. In
undergoing concertina movement, the snake lifts part of its body off the ground to reduce friction; this
cannot be reproduced in planar snake robots. To overcome the inability to adapt to narrow spaces, a
novel type of a gait is introduced. With slight modifications to the members of the multi-link snake
robot, the robot normally developed for lateral undulation is able to utilize the new gait to negotiate
narrow spaces. The modifications include alterations to the snake segments as well elements that
mimic scales on the underside of the snake body. Scales, often overlooked in locomotion research,
play an important role in snake movement by increasing backward and lateral friction while
minimizing it in forward direction. This concept provides the basis for movement in the proposed gait.
Through kinematic studies the viability of this gait is illustrated
- …