1,273 research outputs found
Development of a task-level robot programming and simulation system
An ongoing project in developing a Task-Level Robot Programming and Simulation System (TARPS) is discussed. The objective of this approach is to design a generic TARPS that can be used in a variety of applications. Many robotic applications require off-line programming, and a TARPS is very useful in such applications. Task level programming is object centered in that the user specifies tasks to be performed instead of robot paths. Graphics simulation provides greater flexibility and also avoids costly machine setup and possible damage. A TARPS has three major modules: world model, task planner and task simulator. The system architecture, design issues and some preliminary results are given
History of visual systems in the Systems Engineering Simulator
The Systems Engineering Simulator (SES) houses a variety of real-time computer generated visual systems. The earliest machine dates from the mid-1960's and is one of the first real-time graphics systems in the world. The latest acquisition is the state-of-the-art Evans and Sutherland CT6. Between the span of time from the mid-1960's to the late 1980's, tremendous strides have been made in the real-time graphics world. These strides include advances in both software and hardware engineering. The purpose is to explore the history of the development of these real-time computer generated image systems from the first machine to the present. Hardware advances as well as software algorithm changes are presented. This history is not only quite interesting but also provides us with a perspective with which we can look backward and forward
Certifying Bimanual RRT Motion Plans in a Second
We present an efficient method for certifying non-collision for
piecewise-polynomial motion plans in algebraic reparametrizations of
configuration space. Such motion plans include those generated by popular
randomized methods including RRTs and PRMs, as well as those generated by many
methods in trajectory optimization. Based on Sums-of-Squares optimization, our
method provides exact, rigorous certificates of non-collision; it can never
falsely claim that a motion plan containing collisions is collision-free. We
demonstrate that our formulation is practical for real world deployment,
certifying the safety of a twelve degree of freedom motion plan in just over a
second. Moreover, the method is capable of discriminating the safety or lack
thereof of two motion plans which differ by only millimeters.Comment: 7 pages, 5 figures, 1 tabl
Parallelizing RRT on large-scale distributed-memory architectures
This paper addresses the problem of parallelizing the Rapidly-exploring Random Tree (RRT) algorithm on large-scale distributed-memory architectures, using the Message Passing Interface. We compare three parallel versions of RRT based on classical parallelization schemes. We evaluate them on different motion planning problems and analyze the various factors influencing their performance
Three dimensional simulation of cloth drape
Research has been carried out in the study of cloth modelling over many decades.
The more recent arrival of computers however has meant that the necessary
complex calculations can be performed quicker and that visual display of the
results is more realistic than for the earlier models.
Today's textile and garment designers are happy to use the latest two dimensional
design and display technology to create designs and experiment with patterns and
colours. The computer is seen as an additional tool that performs some of the
more tedious jobs such as re-drawing, re-colouring and pattern sizing.
Designers have the ability and experience to visualise their ideas without the need
for photo reality. However the real garment must be created when promoting
these ideas to potential customers. Three dimensional computer visualisation of a
garment can remove the need to create the garment until after the customer has
placed an order.
As well as reducing costs in the fashion industry, realistic three dimensional cloth
animation has benefits for the computer games and film industries.
This thesis describes the development of a realistic cloth drape model. The
system uses the Finite Element Method for the draping equations and graphics
routines to enhance the visual display. During the research the problem of
collision detection and response involving dynamic models has been tackled and a
unique collision detection method has been developed. This method has proved
very accurate in the simulation of cloth drape over a body model and is also
described in the thesis.
Three dimensional design and display are seen as the next logical steps to current
two dimensional practices in the textiles industry. This thesis outlines current and
previous cloth modelling studies carried out by other research groups. It goes on
to provide a full description of the drape method that has been developed during
this research period
Efficient Path Planning in Narrow Passages via Closed-Form Minkowski Operations
Path planning has long been one of the major research areas in robotics, with
PRM and RRT being two of the most effective classes of path planners. Though
generally very efficient, these sampling-based planners can become
computationally expensive in the important case of "narrow passages". This
paper develops a path planning paradigm specifically formulated for narrow
passage problems. The core is based on planning for rigid-body robots
encapsulated by unions of ellipsoids. The environmental features are enclosed
geometrically using convex differentiable surfaces (e.g., superquadrics). The
main benefit of doing this is that configuration-space obstacles can be
parameterized explicitly in closed form, thereby allowing prior knowledge to be
used to avoid sampling infeasible configurations. Then, by characterizing a
tight volume bound for multiple ellipsoids, robot transitions involving
rotations are guaranteed to be collision-free without traditional collision
detection. Furthermore, combining the stochastic sampling strategy, the
proposed planning framework can be extended to solving higher dimensional
problems in which the robot has a moving base and articulated appendages.
Benchmark results show that, remarkably, the proposed framework outperforms the
popular sampling-based planners in terms of computational time and success rate
in finding a path through narrow corridors and in higher dimensional
configuration spaces
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