3,040 research outputs found
Counterexample Guided Inductive Optimization Applied to Mobile Robots Path Planning (Extended Version)
We describe and evaluate a novel optimization-based off-line path planning
algorithm for mobile robots based on the Counterexample-Guided Inductive
Optimization (CEGIO) technique. CEGIO iteratively employs counterexamples
generated from Boolean Satisfiability (SAT) and Satisfiability Modulo Theories
(SMT) solvers, in order to guide the optimization process and to ensure global
optimization. This paper marks the first application of CEGIO for planning
mobile robot path. In particular, CEGIO has been successfully applied to obtain
optimal two-dimensional paths for autonomous mobile robots using off-the-shelf
SAT and SMT solvers.Comment: 7 pages, 14rd Latin American Robotics Symposium (LARS'2017
A multimodal smartphone interface for active perception by visually impaired
The diffuse availability of mobile devices, such as smartphones and tablets, has the potential to bring substantial benefits to the people with sensory impairments. The solution proposed in this paper is part of an ongoing effort to create an accurate obstacle and hazard detector for the visually impaired, which is embedded in a hand-held device. In particular, it presents a proof of concept for a multimodal interface to control the orientation of a smartphone's camera, while being held by a person, using a combination of vocal messages, 3D sounds and vibrations. The solution, which is to be evaluated experimentally by users, will enable further research in the area of active vision with human-in-the-loop, with potential application to mobile assistive devices for indoor navigation of visually impaired people
A Dexterous Tip-extending Robot with Variable-length Shape-locking
Soft, tip-extending "vine" robots offer a unique mode of inspection and
manipulation in highly constrained environments. For practicality, it is
desirable that the distal end of the robot can be manipulated freely, while the
body remains stationary. However, in previous vine robots, either the shape of
the body was fixed after growth with no ability to manipulate the distal end,
or the whole body moved together with the tip. Here, we present a concept for
shape-locking that enables a vine robot to move only its distal tip, while the
body is locked in place. This is achieved using two inextensible, pressurized,
tip-extending, chambers that "grow" along the sides of the robot body,
preserving curvature in the section where they have been deployed. The length
of the locked and free sections can be varied by controlling the extension and
retraction of these chambers. We present models describing this shape-locking
mechanism and workspace of the robot in both free and constrained environments.
We experimentally validate these models, showing an increased dexterous
workspace compared to previous vine robots. Our shape-locking concept allows
improved performance for vine robots, advancing the field of soft robotics for
inspection and manipulation in highly constrained environments.Comment: 7 pages,10 figures. Accepted to IEEE International Conference on
Rootics and Automation (ICRA) 202
A Comparison of Pneumatic Actuators for Soft Growing Vine Robots
Soft pneumatic actuators are used to steer soft growing "vine" robots while
being flexible enough to undergo the tip eversion required for growth. In this
study, we compared the performance of three types of pneumatic actuators in
terms of their ability to perform eversion, quasi-static bending, dynamic
motion, and force output: the pouch motor, the cylindrical pneumatic artificial
muscle (cPAM), and the fabric pneumatic artificial muscle (fPAM). The pouch
motor is advantageous for prototyping due to its simple manufacturing process.
The cPAM exhibits superior bending behavior and produces the highest forces,
while the fPAM actuates fastest and everts at the lowest pressure. We evaluated
a range of dimensions for each actuator type. Larger actuators can produce more
significant deformations and forces, but smaller actuators inflate faster and
can evert at a lower pressure. Because vine robots are lightweight, the effect
of gravity on the functionality of different actuators is minimal. We developed
a new analytical model that predicts the pressure-to-bending behavior of vine
robot actuators. Using the actuator results, we designed and demonstrated a 4.8
m long vine robot equipped with highly maneuverable 60x60 mm cPAMs in a
three-dimensional obstacle course. The vine robot was able to move around sharp
turns, travel through a passage smaller than its diameter, and lift itself
against gravity.Comment: 13 pages, 8 figures, 3 table
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