Program Objectives and Description
AUSI and IMTP are working together with the goal of investigating the viability of using an SAUV platform to remotely gather oceanographic data and transmit it to a user on a periodic basis. We have broken down this broad goal into three objectives:
1. To answer questions raised during initial
studies and to further develop the SAUV prototype
platform
Earlier studies raised questions concerning discrepancies
between calculated energy acquired under given wave
conditions and actual energy acquired during at sea
testing. In addition, the calculated efficiency of the
SAUV propulsion system was found to be higher than that
measured during at sea testing. This project will focus
on clearing up these issues.
Both AUSI and IMTP are currently working on complementary issues of SAUV research using test platforms based on a common vehicle design. These SAUV test platforms will each be modified to incorporate a more modern and capable RTOS environment with the flexibility to utilize TCP/IP communication protocols. It is very important that we have at our disposal a capable and adaptable target system, which is amenable to embedding in current and future vehicle systems. The choice of an RTOS environment is a key step in the long term process of selecting, integrating and testing new sensors and actuators as part of the SAUV program. Such a target environment must be flexible enough to be easily adapted to new (as yet designed) vehicle systems and be powerful enough to take on new computational duties as projects mature and requirements change. Our current goal is to incorporate Octagon hardware board(s) running QNX alongside existing legacy control boards to provide overall control of the legacy system and provide an interface to the vehicle. AUSI may also explore the use of other board configurations in the future, such as PC/104, that support the QNX RTOS.
Finally, we plan to integrate an AUV command language developed from related research, known as Generic Behaviors, into the vehicle control system using the C++ programming language. We will also explore the possibility of using the Metrowerks IDE for cross-platform development when it becomes available.
2. To investigate the issues associated with
the remote access and real-time control of an SAUV
AUSI has developed an open and flexible, TCP/IP protocol,
client-server simulation environment called the
Cooperative AUV Development Concept (CADCON) for
development of high-level communication and control for
multiple AUVs. CADCON simulation clients are developed in
and run on mid-range PC hardware running well-known
operating systems, and utilize a simple connection
protocol to run over the Internet. We are extending the
capability of CADCON to incorporate hardware-in-the-loop.
Primary advantages to this approach include (1) the
ability to incrementally test many of a real vehicle's
subsystems without the accompanying cost and risk
associated with an at sea test, and (2) providing an
infrastructure for distributing AUV sensor data to
interested researchers and for monitoring and control of
the vehicle during its mission. As CADCON uses TCP/IP
sockets, we would like to preserve this connection
mechanism down to the vehicle level, without the
requirement for developing a serial interface element.
This decision is in line with observed and projected
plans of many AUV research groups (as well as research
groups across many disciplines) to utilize this
well-known protocol in end-to-end system development
efforts.
We will define a detailed strategy for the parallel
development of SAUV vehicles capable of TCP/IP-based
cooperative control. Each of the SAUV systems will
support TCP/IP networking, allowing communication between
the vehicle and the CADCON environment via the Internet.
Issues related to remote monitoring and control, such as
bandwidth limitations, packet delays and data frequency
requirements, and their impact on CADCON system
complexity, will be investigated.
3. To verify the feasibility of using an SAUV
to autonomously acquire oceanographic data and relay that
data to a remote user on a regular basis by conducting a
30 day autonomous data gathering experiment
We will establish operational scenarios to account for
the environmental parameters impacting SAUV system
performance and determine how closely actual performance
matches the calculated performance. We will work on
defining appropriate sensors for the mission and
integrating the sensor suite onto the SAUV. The mission
will be conducted over a 30 day period, with 12-24 hour
updates from the vehicle when it surfaces to recharge its
batteries. Following the mission, we will verify the
quality of the SAUV acquired data by comparison with
similar data acquired by conventional sampling methods.