Efficient locomotion on non-wheeled snake-like robot

This article presents our current work on studying energy efficient locomotion on crawling snake-like robots. The aim of this work is to use existing biological inspired methods to demonstrate lateral undulation planar gaits for efficiently controlling high-speed motion as a function of the terrain surface. A multilink non-wheeled snake-like robot is being developed for experimentation and analysis of efficient serpentine locomotion based on simulation results

Approximate Path-Tracking Control of Snake Robot Joints With Switching Constraints

This paper presents an approximate path-tracking control method for all joints of a snake robot, along with the verification of this method by simulations and experiments. We consider a wheeled snake robot that has passive wheels and active joints. The robot can switch the wheels that touch the ground by lifting the required parts of its body. The model of the robot becomes a kinematically redundant system if certain wheels are lifted. Using this kinematic redundancy, and selecting the appropriate lifted parts, we design a controller for approximate path tracking. Simulations and experimental results show that the proposed controller effectively reduces the path-tracking error for all joints of the snake robot

COCrIP: Compliant OmniCrawler In-pipeline Robot

This paper presents a modular in-pipeline climbing robot with a novel compliant foldable OmniCrawler mechanism. The circular cross-section of the OmniCrawler module enables a holonomic motion to facilitate the alignment of the robot in the direction of bends. Additionally, the crawler mechanism provides a fair amount of traction, even on slippery surfaces. These advantages of crawler modules have been further supplemented by incorporating active compliance in the module itself which helps to negotiate sharp bends in small diameter pipes. The robot has a series of 3 such compliant foldable modules interconnected by the links via passive joints. For the desirable pipe diameter and curvature of the bends, the spring stiffness value for each passive joint is determined by formulating a constrained optimization problem using the quasi-static model of the robot. Moreover, a minimum friction coefficient value between the module-pipe surface which can be vertically climbed by the robot without slipping is estimated. The numerical simulation results have further been validated by experiments on real robot prototype

Learning Ground Traversability from Simulations

Mobile ground robots operating on unstructured terrain must predict which areas of the environment they are able to pass in order to plan feasible paths. We address traversability estimation as a heightmap classification problem: we build a convolutional neural network that, given an image representing the heightmap of a terrain patch, predicts whether the robot will be able to traverse such patch from left to right. The classifier is trained for a specific robot model (wheeled, tracked, legged, snake-like) using simulation data on procedurally generated training terrains; the trained classifier can be applied to unseen large heightmaps to yield oriented traversability maps, and then plan traversable paths. We extensively evaluate the approach in simulation on six real-world elevation datasets, and run a real-robot validation in one indoor and one outdoor environment.Comment: Webpage: http://romarcg.xyz/traversability_estimation

Mechanical Design and Dynamic Analysis of Pipe Crawling Robot for Internal Gas Pipeline Inspection

Pipelines play an important role in terms of transporting various types of fluid like liquid and gas. They are mainly used not only in small applications like housing area, but also in large industrial field like in an oil and gas field. Maintenance of these pipelines is crucial and the cost of doing it continues to increase from time to time and thus a new approach is needed in order to tackle these problems. This project report presents the design and development of crawling robots for internal pipe inspection. There are four designs being considered but this paper will present the simplest of the design which is the wheeled type design that with a pantograph mechanism with a sliding base that allows folding and unfolding of the robot’s legs. The mechanism of this robot is based on the design of MRINSPECT III and the driving mechanism of MRINSPECT IV. The robot is designed accordingly so that it can function through a pipeline ranging from 6 inches diameter to 10 inches diameter. The design is then modeled and simulated using AutoCAD and ADAMS respectively