A strong component of current underwater robotics work lies in the realm of multiple
vehicles and instrument platforms (VIPs). Successful fielding of functional multiple
VIP systems will require that we first gain experience with the issues pertaining to
the interactions between the participants, who must cooperate in order to accomplish
complex and dynamic long term missions. Many current simulation tools are directed
towards investigations into the motion characteristics of vehicle body styles and
their propulsion systems. While these tools are essential in the design of vehicle
bodies, they do not directly address the issues of cooperative behavior among a team
of VIPs. There is a scarcity of tools geared towards the needs of researchers working
with multiple cooperating VIPs. To answer this need, we have developed the Cooperative
AUV Development Concept (CADCON).
The chief idea behind CADCON is that it provide an open and flexible
simulation environment for use by as many researchers as
possible. Understanding that no single simulation harness could capture the
full fidelity of the real open ocean environment of a deployed
Autonomous Oceanographic Sampling Network (AOSN), nor the
complexity of every sort of vehicle that might participate, we have
attempted to focus CADCON on one of the stickiest problems we see in systems
as complex as an AOSN: the issues associated with the interactions among
multiple heterogeneous agents; be those agents simulations, real vehicles,
or human users. To that end, we specify that the CADCON simulation
environment adhere to the following points:
- Utilize well-known ubiquitous hardware.
All CADCON components have been developed to run on today's most
available platform: the IBM compatible computer. This allows workers
to leverage well known, cheap, and accessible hardware, making their
participation in CADCON simulations relatively easy and
flexible. Exotic hardware is not required.
- Utilize a well-known ubiquitous communication protocol.
CADCON environment components are implemented following the
client/server model and communication between them is in the lingua
franca of the Internet: TCP/IP. This non-reliance on proprietary
communications protocols further leverages the system's utility and
availability to other workers.
- Be globally accessible.
Since components communicate via TCP/IP sockets, they may be
distributed across intranets as well as the Internet. This opens the
door to geographically distant institutions participating in joint
- Open to any institution's AUV development style.
The client/server model fosters modular development. Coupling this
with the use of the TCP/IP protocol fosters a high degree of
platform/language independence for client developers. This allows
great flexibility for distributed researchers to connect existing
legacy simulation models or create new models on the platform and in
the programming language of their choice.
- Allow for real hardware in the loop simulation.
The modularity encouraged by clients communicating with servers via
TCP/IP also provides for easy integration of real vehicles into the
CADCON environment. This moves CADCON out of the strictly simulation
arena. Real vehicles will react to situations presented by the
CADCON simulator while safely on the bench. Given a physical
communication link, this concept can be taken even further to where
real vehicles situated in actual missions will begin to supply the
CADCON environment with in situ data.
- Access via the World Wide Web.
The current instance of the CADCON environment is now available on
the Web. In the spirit of open and free exchange of ideas, users are
encouraged to download example clients from the AUSI web site and
try them out against a running simulator.
More information can be found in the paper: An
Environment for High-Level Multiple AUV Simulation and Communication