  When developing general purpose robots, the overarching software architecture
can greatly affect the ease of accomplishing various tasks. Initial efforts to
create unified robot systems in the 1990s led to hybrid architectures,
emphasizing a hierarchy in which deliberative plans direct the use of reactive
skills. However, since that time there has been significant progress in the
low-level skills available to robots, including manipulation and perception,
making it newly feasible to accomplish many more tasks in real-world domains.
There is thus renewed optimism that robots will be able to perform a wide array
of tasks while maintaining responsiveness to human operators. However, the top
layer in traditional hybrid architectures, designed to achieve long-term goals,
can make it difficult to react quickly to human interactions during goal-driven
execution. To mitigate this difficulty, we propose a novel architecture that
supports such transitions by adding a top-level reactive module which has
flexible access to both reactive skills and a deliberative control module. To
validate this architecture, we present a case study of its application on a
domestic service robot platform.
