The OmniTread OT-4 serpentine robot—design and performance

Serpentine robots are slender, multi-segmented vehicles designed to provide greater mobility than conventional mobile robots. Serpentine robots are ideally suited for urban search and rescue, military intelligence gathering, and inspection tasks in hazardous or inaccessible 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 six 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 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. The pneumatic bellows allow the simultaneous control of position and stiffness for each joint. Controllable stiffness is important 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 coverage of all four sides of each segment with drive tracks. This design makes the robot indifferent to rollovers, which are bound to happen when the slender bodies of serpentine robots travel over rugged terrain. This paper describes the OmniTread concept and some of its technical features in some detail. In the Experiment Results Section, photographs of successful obstacle traverses illustrate the abilities of the OT-4. © 2007 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56171/1/20196_ftp.pd

Mechanical Description of a Hyper-Redundant Robot Joint Mechanism Used for a Design of a Biomimetic Robotic Fish

A biologically inspired robot in the form of fish (mackerel) model using rubber (as the biomimetic material) for its hyper-redundant joint is presented in this paper. Computerized simulation of the most critical part of the model (the peduncle) shows that the rubber joints will be able to take up the stress that will be created. Furthermore, the frequency-induced softening of the rubber used was found to be critical if the joints are going to oscillate at frequency above 25 Hz. The robotic fish was able to attain a speed of 0.985 m/s while the tail beats at a maximum of 1.7 Hz when tested inside water. Furthermore, a minimum turning radius of 0.8 m (approximately 2 times the fish body length) was achieved

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

A Tread/Limb/Serpentine Hybrid Robot: Toward Hypermobility in Deconstructed Environments

According to the Red Cross, an average of over 600 disasters and 100,000 associated deaths occur annually throughout the world. This frequency of disasters strains an already overburdened disaster response effort. In the first 48 hours of a rescue operation, it is estimated that a responder will get less than three hours of continuous sleep as they need to work at full force to set up the operation and begin work in the field. This leads to sleep deprivation during the most critical time for search and rescue of victims. Therefore, robots are greatly needed as a force multiplier in USAR response to reduce some of the burden and workload placed on the human rescue workers to make for a more efficient and effective response