Designing For System Intelligence
Sesh Commuri
1
, Yushan Li
1
, Dean Hougen
2
, Rafael Fierro
3
1
School of Elec. & Comp. Engg., University of Oklahoma, Norman, OK 73072
2
School of Comp. Science, University of Oklahoma, Norman, OK 73072
3
School of Elec. & Comp. Engg., Oklahoma State University, Stillwater, OK 74078
Abstract: This paper presents a hierarchical architecture for the realization of teams of
intelligent autonomous ground vehicles called Adaptation and Learning at All Levels
(AL
2
). Requirements on system intelligence are translated into requirements on the
system hardware and software. Recent trends in the hardware-software co-design and
hardware reconfiguration that enable the realization of these requirements are then
introduced and the design methodology is discussed. Examples are provided to illustrate
the design methodology. Copyright © 2004 IFAC
Keywords: Architectures, intelligent systems, autonomous mobile vehicle.
1. INTRODUCTION
In recent years, mobile robots have evolved from the
humble origins of Autonomous Ground Vehicles
(AGVs) in manufacturing applications to complex
multi-vehicle robotic teams that are expected to
coordinate and function cooperatively to satisfy
specified objectives. The high cost associated with
the acquisition and deployment of mobile robots
motivates the development of low cost multi-robot
teams that can function cooperatively to achieve
specified goals. As the performance requirements get
more stringent and the application realm become
more diverse, embedding “Intelligence” in the mobile
robots becomes critical to the realization of Intelligent
Autonomous Vehicles. While a number of techniques
were proposed in literature for the control and
coordination of multi-robot teams, the use of these
systems is constrained due to the inflexible hardware
and software implementations.
Designing systems that are intelligent is substantially
more complex than just the integration of smart
controllers or transducers (IEEE 1451.1, 1451.2,
1999a,b). Embedding intelligence into systems
requires a new design paradigm that takes into
account the hardware and software complexities
involved in the design of embedded systems (Albus et
al. 2000a,b). The design must address issues such as:
y intelligent sensor selection and sensor fusion,
y fault detection and accommodation,
y dynamic reconfigurability and high levels of
reliability under all operating conditions,
y hierarchical architecture for implementing hybrid
controllers,
y sophisticated algorithms for implementing
adaptive behaviours,
y remote operation and coordination with other
controllers, and
y provision for system evolution, and paths for the
migration of capabilities.
The design must also address real-time and non real-
time issues in sensor fusion, communication between
network nodes, and the automation of the decision
making process.
Many methods have been suggested for controlling
multi-robot systems (Cao et al., 1997, Dudek et al.
1996). Some of these use a centralized planning
approach to make efficient use of resource (Bonasso
et al., 1997, Schreckenghost et al., 1998). In contrast,
the requirement for loss tolerance has lead many
researchers to consider distributed systems (Balch et
al. 1998, Parker et al. 1998). More recently, attention
has been paid to design architectures that combine the
advantages of both centralized and distributed
approaches (Simmons et al., 2002).
While the selection of the right architecture plays an
important role in the design of the system, the
ultimate performance depends on the software and the
algorithms implemented therein. In recent years,
adaptation and learning have been proved to be an
effective way to enable robots to carry out complex
IAV2004 - PREPRINTS
5th IFAC/EURON Symposium on Intelligent Autonomous Vehicles
Instituto Superior Técnico, Lisboa, Portugal
July 5-7, 2004