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

A snake robot with mixed gaits capability

Snake robots are mostly designed based on single mode of locomotion. However, single mode gait most of the time fails to work effectively when they are required to work in different cluttered environment with different measures of complexity. As a solution, mixed mode locomotion is proposed in this paper by synchronizing serpentine gait for unconstricted workspace and wriggler gait for narrow space environment through development of a simple gait transition algorithm. This study includes the investigation on kinematics analysis followed by dynamics analysis while considering related structural constraints for both gaits. This approach utilized speed of the serpentine gait for open area operation and exploits narrow space access capability of the wriggler gait. Hence, this approach in such a way increases motion flexibility in view of the fact that the snake robot is capable of changing its mode of locomotion according to the working environment

Rolling-joint design optimization for tendon driven snake-like surgical robots

The use of snake-like robots for surgery is a popular choice for intra-luminal procedures. In practice, the requirements for strength, flexibility and accuracy are difficult to be satisfied simultaneously. This paper presents a computational approach for optimizing the design of a snake-like robot using serial rolling-joints and tendons as the base architecture. The method optimizes the design in terms of joint angle range and tendon placement to prevent the tendons and joints from colliding during bending motion. The resulting optimized joints were manufactured using 3D printing. The robot was characterized in terms of workspace, dexterity, precision and manipulation forces. The results show a repeatability as low as 0.9mm and manipulation forces of up to 5.6N

Design of an Electromechanical Prosthetic Finger using Shape Memory Alloy Wires

This research concerns the design and prototyping of an artificial middle finger, using Shape Memory Alloys (SMAs), PolyLactic Acid (PLA), and other technologies. The design is a biomimicry of the human biological anatomical and muscular systems. After briefly describing the operational features and functioning of natural striated muscles, the document reviews the features, advantages and disadvantages of SMAs in the perspective of their use as an actuator of a prosthetic finger.Using different design parameters, such as the lightness of the device, actuation complexity, and resilience, a working prototype is proposed meeting the established criteria

The role of functional surfaces in the locomotion of snakes

Snakes are one of the world’s most versatile organisms, at ease slithering through rubble or climbing vertical tree trunks. Their adaptations for conquering complex terrain thus serve naturally as inspirations for search and rescue robotics. In a combined experimental and theoretical investigation, we elucidate the propulsion mechanisms of snakes on both hard and granular substrates. The focus of this study is on physics of snake interactions with its environment. Snakes use one of several modes of locomotion, such as slithering on flat surfaces, sidewinding on sand, or accordion-like concertina and worm-like rectilinear motion to traverse crevices. We present a series of experiments and supporting mathematical models demonstrating how snakes optimize their speed and efficiency by adjusting their frictional properties as a function of position and time. Particular attention is paid to a novel paradigm in locomotion, a snake’s active control of its scales, which enables it to modify its frictional interactions with the ground. We use this discovery to build bio-inspired limbless robots that have improved sensitivity to the current state of the art: Scalybot has individually controlled sets of belly scales enabling it to climb slopes of 55 degrees. These findings will result in developing new functional materials and control algorithms that will guide roboticists as they endeavor towards building more effective all-terrain search and rescue robots.Ph.D

Applied Measurement Systems

Measurement is a multidisciplinary experimental science. Measurement systems synergistically blend science, engineering and statistical methods to provide fundamental data for research, design and development, control of processes and operations, and facilitate safe and economic performance of systems. In recent years, measuring techniques have expanded rapidly and gained maturity, through extensive research activities and hardware advancements. With individual chapters authored by eminent professionals in their respective topics, Applied Measurement Systems attempts to provide a comprehensive presentation and in-depth guidance on some of the key applied and advanced topics in measurements for scientists, engineers and educators

Metodología de diseño de manos robóticas basada en los estados de su sistema accionador

La mano humana es una de las herramientas más asombrosas de la naturaleza, tanto que no ha podido ser superada en ningún aspecto hasta el momento. Siendo el principal medio por el cual se ha creado y construido, directa o indirectamente, todo lo artificial que actualmente nos rodea, es natural pensar de que gran parte de la comunidad científica relacionada con la robótica dedique grandes esfuerzos por imitarla. En la actualidad se puede realizar un extenso catálogo de manos robóticas desarrolladas y todas buscan resolver un determinado comportamiento de la mano humana, aún así, éstas se pueden dividir en tres grupos bien definidos: las pinzas robóticas, las cuales se caracterizan por su aplicación industrial en tareas de agarre firme de elementos específicos y por su robustez, precio y vida útil; por otro lado, están las manos robóticas subactuadas en las que se buscan mecanismos cada vez más complejos que hagan disminuir la cantidad de actuadores y la complejidad de su sistema de control a favor de mejorar la funcionalidad de las pinzas robóticas en lo que se refiere a extender su capacidad de agarre a objetos con formas y tamaños cada vez más diferentes; y finalmente encontramos las demás manos robóticas en las que su objetivo es la experimentación de un determinado comportamiento de la mano humana más centrada en las tareas de manipulación. Esta tesis propone una metodología de diseño de manos robóticas desde un punto de vista particular, que es el de los estados que puede ofrecer su sistema de accionamiento, teniendo en cuenta la capacidad de combinarlos y hacerlos independientes. Los elementos móviles que componen una mano robótica son accionados por un actuador o conjunto de actuadores. El sistema accionador es el órgano principal que da vida a un determinado sistema robótico como una mano robótica, por lo tanto es preciso identificar la capacidad que tiene el mismo de hacer que ese movimiento pueda generar tareas cada vez más complejas. La forma de identificar esta capacidad se resume en los estados y la calidad de los mismos que el sistema accionador puede ofrecer. Esta metodología de diseño se basa fundamentalmente en este concepto y que si bien en este trabajo es aplicado a manos robóticas, puede ser extendido a cualquier sistema robótico que disponga de un sistema accionador y de esta forma optimizar sus recursos no sólo a nivel funcional, sino también en el ahorro de energía. En el transcurso de este trabajo se han diseñado dos manos robóticas con esta metodología y se ha realizado un ensayo de viabilidad técnica de un actuador capaz de ofrecer un número finito de estados mayor a los tres que ofrece actualmente cualquier actuador. Estos diseños han demostrado que este tipo de metodología puede ofrecer una alternativa para la optimización del sistema accionador de una mano robótica. Por otro lado, la misma también puede ser aplicada a cualquier tipo de mano robótica y para cualquier aplicación y servir como una herramienta útil para el análisis del diseño de las manos robóticas actuales y buscar puntos de optimización para futuros desarrollos