LOCOMOTION AND CROSSING MEANS OF LAND ROBOTS

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 The rovers are small automated vehicles built to perform a specific task : planetary exploration, research assistance in disasters, monitoring.
They have to cross any terrain and for this new or improved locomotion modes are emerging from about three decades in laboratories. Hundreds (or thousands) of models of robots are built whose a small amount is sold.
To find new means of locomotion, some researchers inspire by living things, that they do not use wheel or caterpillar.

I - LEGGED ROBOTS :

Robert J. Full, a biologist at Berkeley, studies scientifically locomotion of animals with many legs : crabs, ants, cockroaches, centipedes, geckos and his research is used for the making of legged robots. The idea is that the legs can overcome the obstacles that the wheels do not. But the robots legs proved complicated, slow and they often need a fairly flat and harsh terrain.

Photo 1 : Although there are one legged robots (to the MIT Leg Laboratory), 2 legged robots performing are represented by the Honda Asimo, very successful with its humanoid form mimicking to perfection the walking and running of man. It goes up and down stairs, but if it falls, it seems unable to recover, but it is improved.
http://www.youtube.com/watch?v=d-htzy0xZpo&mode=related&search

Photo 2 : Models like the Big Dog with petrol engine and hydraulic pumps from Boston Dynamics can walk 5 km / h with 50 kg of cargo without tipping and imitate the jump and kick of the horse : Awesome !
http://fr.youtube.com/watch?v=mBCVprX0WnY&mode=related&search  
The PAW galloper robot with 4 legs and wheels of James Andrew Smith of Mc Gill Research Center looks like a real dog.
http://www.youtube.com/watch?v=koTvt34b0AE  
We may signal the Robofrog of NASA which is a hopping robot.

Photo 3 : Famous forerunner, Shigeo Hirose, Director of the Institute of Technology in Tokyo began in 1976 his research on legged vehicles with Kumo I. There followed a series of walking robots of all kinds including Roller-Walker (1995-present) (photo) that can walk but also run with self-adaptable no drive wheels to end legs : thanks to particular movements of its legs imitating a skater spreading and strengthening their skates : it moves forward and steer.
http://www-robot.mes.titech.ac.jp/robot/walking/rollerwalker/rollerwalker_e.html

Photo 4 : Lauron III, built at FZI of Karlsruhe, advance through its 6 feet to 3 degrees of freedom and its 3 directions sensors feet. A laser and landforms recognition software associated with numerous sensors enable local navigation on unstructured terrain.
http://haydn.upc.es/groups/arobots/legged_robots/default.htm  
http://www-iri.upc.es/groups/arobots/legged_robots/default.htm  
http://www.fzi.de/ids/projekte.php?id=18

Photo 5 : Rhex, of Universities of Michigan and California, is equipped with 6 legs that rotate like wheels. Like cockroaches, it can move anywhere and even upside down on the sand, mud, on rocks. He can also jump, do a back somersault. This robot simple and really off-road is a success. An amphibious version exists and it is now marketed by Boston Dynamics. 
http://www.bostondynamics.com/content/sec.php?section=RHex  
Include the robot Rise to 6 feet of the same company that can climb vertical surfaces with mini-claws and sticky materials in the image of a gecko, lizard which can move on vertical surfaces.
http://www.bostondynamics.com/content/sec.php?section=RiSE  

Photo 6 : Halluc II of Chiba Institute of Technology with 8 articulated legs themselves equipped with wheels offers many opportunities for advancement:
http://www.youtube.com/watch?v=1-0iXUZZFSg&mode=related&search  
http://www.youtube.com/watch?v=8KFXO2Hx4tw&mode=related&search  
Polypod with 2 to 10 legs of Lynxmotion is a marketed robot.
http://www.robotshop.ca/home/suppliers/lynxmotion-en/lynxmotion-ep2-kt-polypod-segment-kit.html  
http://fr.youtube.com/watch?v=nPXRw0Rr9Ug

II - WHEELED ROBOTS :

It may be noted first a 'Soft Spherical Robot' from Ritsumeikan University, sphere that deforms slowly for a few seconds and suddenly it jumps !! Surprising !

Photo 7 : Equipped with a pneumatic system, the 2 wheeled robot Leg-in-Robot V can also jump on or over obstacles. Two electric wheels enable it to run on relatively flat terrain. It is designed to help in rubble cluttered building with enough space for the jump.
http://www.cm.ctrl.titech.ac.jp/study/jump/home.html  

Photo 8 : Shigeo Hirose has built in 1995-97 an omnidirectional 3 wheels planetary exploration robot, the Tristar. The chassis is deployed at the exit of the container and the wheels are expandable.

Photo 9 : Exploration articulated 4x4 Nanorover spring spoked wheels LAMAlice in 1999 at the Ecole Polytechnique Federale de Lausanne (EPFL).
http://asl.epfl.ch/research/systems/LAMAlice/lamalice.php

Photo 10 : The suspension system of Sojourner Rocker Bogie's JPL (Jet Propulsion Laboratory) of NASA is best known through the expeditions on Mars. It is a simple passive system in balance.

Photo 11 : The Marsokhod studied in St. Petersburg was tested in the U.S. and France, especially at INRIA Toulouse. It was part of the European expedition in March 1998, which ended in failure. Fully articulated liabilities, the frame can still elongates (inching system) for easier moving on steep slopes.

Photo 12 : This gave birth to Iarès tested at INRIA of Toulouse. Equipped with independent wheels, it can remain horizontal on the slopes.

Photo 13: The Shrimp of BlueBotics, company affiliated with the EPFL, is an original articulated 6x6. The passive joints and arms fit the profile of the terrain. Designed for planetary exploration, it was also thought to use for disable mobility.
http://www.bluebotics.com/solutions/Shrimp/spec.pdf 

http://asl.epfl.ch/research/systems/Shrimp/videos/shrimp.mpg  
http://asl.epfl.ch/research/systems/Shrimp/shrimp.php

Photo 14 : Eight wheels Athlete of Brian Wilcox of JPL for NASA's for Mars exploration can climb slopes horizontally with large articulated arms.
http://www.youtube.com/watch?v=n_Bs8dAJsHE

 
Photo 15 : 8x8 Octopus of EPFL has sensors in the rims of wheels for controlling the movement of articulated arms in the direction that overcomes obstacles.
http://asl.epfl.ch/aslInternalWeb/ASL/publications/uploadedFiles/Octopuspaper.pdf

 Photo 16 : Genbu, firefighter robot of S. Hirose, can have 20 wheels on a chassis made of a flexible hose.

Photo 17 : The Toolkit of Collineo and DRDC (Defense R & D Canada) has legs in two parts
The Collineo Company, Drummondville, Quebec, a service company helping high-tech industries in the areas of civil protection and field operations, creates all-terrain robots such as micro-hydraulic reconfigurable Toolkit 4 or 6 wheels, in collaboration with DRDC Suffield (Defense R & D Canada). It includes suspension arm in two parts and 14 degrees of freedom with electric motors or hydraulic units. These arms can best bridge and climb the difficult slopes by reducing the action of the wheels at the expense of arms that mimic walking : the center of gravity moves (inching system or peristaltic mode) without wheels. The robot Hylos of the Institute for Intelligent Systems and Robotics, Paris, and Work Partner of Helsinki University, Finland, had also articulated arms with wheels. The articulated 6x6 Marsokhod robot too, originally studied in Saint Petersburg by the Company Transmash has an expandable frame (but no legs) that allows it to accompany action of wheels.
http://pubs.drdc.gc.ca/PDFS/unc78/p530428.pdf

III - TRACKED ROBOTS :

Photo 18 : Not exactly tracked, the ELMS (Elastic Loop Mobility System) is the prototype of a planetary exploration system for years 70's and 80's consists of titanium rolling curved rings. This new concept is less heavy than tracks and climbs higher.

Photo 19 : The robot Aurora Automatika in Pennsylvania built by Hagen Schempf in 1999, consists of a single and directional track. Very original !

Photo 20 : The University of Wuerzburg built this robot, a two tracked Nanokhod more an articulated pendulum used as a weight-cons, itself made of a caterpillar. It can move horizontally on the slopes.

Photo 21 : Chiba Institute of Technology built the Hibiscus. It is equipped with 2 central tracks covering the entire width of the machine. Four additional tracks to the front and rear can execute complete rotations and behave as rotating legs.
http://www.furo.org/robot/Hibiscus/movie.html  

Photo 22: Featuring 2 triangular tracks, SNR1 of the AIST (National Institute of Advanced Industrial Science and Technology) has another one at the rear like an articulated tail.
http://staff.aist.go.jp/kamimura.a/index.htm  

Photo 23 : The STRV Shape-Shifting Tracked Robotic Vehicle by DRDC, Defense Research and Development, Suffield, Alberta looks like the Telemax of the University of Bremen and the "KOHGA2" from Fumitoshi Matsuno, University of Electro-Communications, Japan or the Chaos of Autonomous Solutions, West Petersboro, Utah, which has the same configuration.
http://www.cbc.ca/news/background/tech/robotics/military.html  
http://www.rheinmetall-defence.com/index.php?lang=3&fid=3392
http://www.rescuesystem.org/tmp/NEW/en/robot.htm 
http://www.autonomoussolutions.com/products/chaos.php

IV - SNAKE ROBOTS :

To go forward, a real snake takes support on points following the ground bumps from which it deforms and pushes on these points, causing reactions of the ground on the snake and makes move it. These points are located at the rear of each curve, moving continuously as the snake feels the roughness of the soil and executes its deformations accordingly.
Skaters almost static approximate and removing their skates cause the same effects : they move.
We can attribute the early research on creep to Shigeo Hirose at the Tokyo Institute of Technology. After studying the movement of snakes in 1970, he designed the ACM III (Active Cord Mechanism) and in 1972 for the first time ever, an artificial animal moved by lateral creep.

He subsequently built the snake robot ACM-R3 (2002) with 1 degree of freedom offset by 90° controlled by software. Passive wheels (non-driven) are there to help sliding.
http://www-robot.mes.titech.ac.jp/robot/snake/acm-r3/acm-r3_e.html

Photo 24 : More like Polybots of PARC (Palo Alto Research Center, a subsidiary of Xerox), use vertical creep like caterpillars of butterflies.
http://www2.parc.com/spl/projects/modrobots/videos/headturnsnake.mov  
http://www2.parc.com/spl/projects/modrobots/videos/obstcourse.mpg  
We just mention that Polybots can also automatically reconfigure into rings, in legged robots or networks to adapt to the environment.
The snake-robots of PARC have been advanced by the NASA Ames Research Center for planetary exploration. The new models behave well but if the land becomes chaotic, points of contact with the ground vary irregularly and the software managing lateral deformations does not find ground support if it does not know the position of points. Then sensors are located at each joint to 'feel' the ground. This is what make S. Hirose with ACM-R4, but NASA and its competitors, which include sensors at each joint snake robots in their 3rd generation.

Photo 25 : It appears that appropriate software is being developed but in the meantime, S. Hirose had the idea of making the drive wheels of the ACM-R4. Here, the robot can then climb on a chair without really crawling.
http://www-robot.mes.titech.ac.jp/robot/snake/acm-r4/acm-r4.html

Photo 26 : This solution is easier than lateral crawling and number of snake robots as Soryu, Moira, Kohga, Swarm Bot, Millibot and OT4 of University of Michigan (photo) do not use drive wheel but caterpillars on the four sides of 7 elements, themselves equipped with pneumatic bellows for controlling joints.
http://www.engin.umich.edu/research/mrl/00MoRob_6.html

This is no more lateral creep but the results are there : thanks to their great length and small cross-section, associated with many joints controlled in pitch and direction, they can sneak more than any mechanism among the ruins of a building and cross very large obstacles in relation to their size. Whatever the shape of the field, there remain several points of contact with the floor, walls and / or ceiling for their propulsion. The system even allows them to turn on themselves laterally through the controls of joints.

In the field of terrestrial locomotion, crawling seems promising in terms of crossing, but research must continue before a practical use.