Serpentine robots are slender, multi-segmented vehicles designed to provide greater mobility than conventional
wheeled or tracked robots. Serpentine robots are thus ideally suited for urban search and rescue, military intelligence
gathering, and for surveillance and inspection tasks in hazardous and hard-to-reach environments. One such serpentine
robot, developed at the University of Michigan, is the "OmniTread OT-4." The OT-4 comprises seven segments, which
are linked to each other by 2-degree-of-freedom joints. The OT-4 can climb over obstacles that are much higher than the
robot itself, propel itself inside pipes of different diameters, and traverse even the most difficult terrain, such as rocks or
the rubble of a collapsed structure.
The foremost and unique design characteristic of the OT-4 is the use of pneumatic bellows to actuate the joints.
These bellows allow simultaneous control of position and stiffness for each joint. Controllable stiffness is of crucial importance
in serpentine robots, which require stiff joints to cross gaps and compliant joints to conform to rough terrain for
effective propulsion. Another unique feature of the OmniTread design is the maximal coverage of all four sides with
driven tracks. This design makes the robot indifferent to roll-overs, which are happen frequently when the slender bodies
of serpentine robots travel over rugged terrain.
This paper describes the OmniTread concept as well as its latest technical features, and an extensive Experiment Results
Section documents the abilities of the OT-4.
This paper describes the design and performance of the OmniTread serpentine robot, developed at the University of Michigan. Serpentine robots are mobile robots that comprise of multiple rigid segments, connected by actuated joints. The segments usually have drive elements, such as wheels or tracks. To date, we have developed two versions of the OmniTread. The larger version, called OT-8, has five rigid segments and four 2-Degree-of-Freedom (2-DOF) joints, and it can drive through an 8-inch diameter opening. The OT-8 is fully functional and this paper documents experimental results for the OT-8. The smaller and newer version, called "OT-4," will have seven segments, six 2- DOF joints, and it will fit through a 4 inch diameter hole. The OT-4 is not yet completely built, but its design is mostly completed and key improvements over the OT-8 have been bench tested. The foremost and unique design characteristic of the OmniTread is the use of pneumatic bellows to actuate the joints. The pneumatic bellows allow the simultaneous control of position and stiffness for each joint. Controllable stiffness is of crucial importance in serpentine robots, which require stiff joints to cross gaps and compliant joints to conform to rough terrain for effective propulsion. Another unique feature of the OmniTread design is the maximal coverage of all four sides of each segment with driven tracks. This design makes the robot indifferent to roll-overs, which are bound to happen when the long and slen-der bodies of serpentine robots travel over rugged terrain.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.