2 research outputs found
Towards Plan Transformations for Real-World Pick and Place Tasks
In this paper, we investigate the possibility of applying plan
transformations to general manipulation plans in order to specialize them to
the specific situation at hand. We present a framework for optimizing execution
and achieving higher performance by autonomously transforming robot's behavior
at runtime. We show that plans employed by robotic agents in real-world
environments can be transformed, despite their control structures being very
complex due to the specifics of acting in the real world. The evaluation is
carried out on a plan of a PR2 robot performing pick and place tasks, to which
we apply three example transformations, as well as on a large amount of
experiments in a fast plan projection environment
Contractibility for Open Global Constraints
Open forms of global constraints allow the addition of new variables to an
argument during the execution of a constraint program. Such forms are needed
for difficult constraint programming problems where problem construction and
problem solving are interleaved, and fit naturally within constraint logic
programming. However, in general, filtering that is sound for a global
constraint can be unsound when the constraint is open. This paper provides a
simple characterization, called contractibility, of the constraints where
filtering remains sound when the constraint is open. With this characterization
we can easily determine whether a constraint has this property or not. In the
latter case, we can use it to derive a contractible approximation to the
constraint. We demonstrate this work on both hard and soft constraints. In the
process, we formulate two general classes of soft constraints.Comment: Under consideration in Theory and Practice of Logic Programming
(TPLP