AUV Workbench: Integrated 3D forInteroperable Mission Rehearsal, Reality and Replay

Jeffrey Weekley

Naval Postgraduate School,

Monterey, CA USA

jdweekley@nps.navy.mil

Overview

• Background

• XML Basics

• XML as a Common Ground for AUVs

• XML-based Tools

• The AUV Workbench

• Related Efforts

• Conclusion and Q&A

Background

• Multiple System Proliferating

• Data is ephemeral

• XML is a Best Business Practice

• Proprietary technologies vs. Open Standards

XML Basics

The key to interoperability is structured data interchange.

• XML is for structuring data

• XML looks a bit like HTML

• XML is text, but isn't meant to be read

• XML is verbose by design

• XML is a family of technologies

•XML is new, but not that new

•XML leads HTML to XHTML

•XML is modular

•XML is the basis for RDF and the Semantic Web

•XML is license-free, platform-independent and well-supported

XML as a Common Ground for AUVs

N2

versus

2N System System

System

XML

System System

AUV Tactical Markup Language

• Many AUVs and their systems share multiple characteristics

• In XML terms, these are called ‘Elements and Attributes’

• Elements and Attributes not well defined for AUVs

XML Schema for AUVs

• Schemas describe the structure and constraining the contents of XML

• Applications read and understand Schemas

• Schemas greatly enhance the power of XML – Garbage in / Garbage Out No More!

<?xml version="1.0" encoding="UTF-8" ?>- <!-- edited with XMLSPY v5 rel. 2 U (http://www.xmlspy.com) by Barbara VanLeuvan (Naval Postgraduate School) -->- <!--This schema describes the AUV mission scripting. Refer to the mission.script.Help file for a description of the commands. -->

- <xs:schema xmlns:xs=http://www.w3.org/2001/XMLSchema elementFormDefault="qualified" attributeFormDefault="unqualified">-<xs:annotation>

<xs:documentation>Start of defining data types</xs:documentation>

</xs:annotation>- <xs:simpleType name="absoluteHeadingType">- <xs:annotation>

<xs:documentation>Defines valid absolute heading values</xs:documentation>

</xs:annotation>- <xs:restriction base="xs:decimal"><xs:minInclusive value="0" /><xs:maxInclusive value="359.9" /></xs:restriction></xs:simpleType>

An Example of AUV Tactical Markup Language

Value for Attribute

XFSP

• XML documents are verbose by design

• Their transmission in noisy environments is impractical

• XFSP is a general approach to binary serialization of XML well-suited for use with AUVs

• Suitable for message streams and large document transmission (even imagery)

A Simple Address Book Example<name>

<first>John</first><last>Doe</last>

</name>

Tag Name Start Tag Number End Tag Number Data Type

name 11 20 SFString

first 21 30 SFString

last 31 40 SFString

<11><21>John<30><31>Doe<40>

<20>

Sample Compression Rates

129

111

84

34 3329

0

20

40

60

80

100

120

140

x3d wrl b3d zip_x3d zip_wrl b3z

File Formats

Siz

e in

KB

yte

Forward Error Correction (FEC) with Hamming Codes

• Forward Error Correction (FEC) increases the ability of a receiving station to correct a transmission error

• It allows a receiver-side error detection and correction without retransmission

• The serialization of XML makes implementing Hamming Codes for AUVs much more feasible

The AUV Workbench

Sample Mission Script

<?xml version="1.0" encoding="utf-8"?><auv-mission vehicle="aries"> <mission> <position x="12" y="80" depth="5"/> <propeller rpm="700"/> <thrusters/> <standoff range="0.75"/> <waypoint x="110" y="80" depth="15"/> <hover/> <heading value="90"/> <wait time="10"/> <waypoint x="110" y="95"/> <hover/> <heading value="180"/> <wait absolute="false" time="10"/> <waypoint x="20" y="95" depth="5"/> <hover/> <heading value="270"/> <wait time="10"/> <hover x="12" y="80" depth="5"/> <heading value="0"/> <wait time="10"/> <propeller rpm="0"/> <thrusters on="false"/> </mission></auv-mission>

position 12 80 5speed 700thrusters-on

standoff-distance .75

waypoint 110 80 15hover course 90wait 10

waypoint 110 95 15hover course 180wait 10

waypoint 20 95 5hover course 270wait 10

hover 12 80 5course 0wait 10

speed 0thrusters-off

2D & 3D Mission Planner

Network Support for Distributed Simulations

• DIS is an IEEE Protocol

• Works over standard TCP/IP (The Web)

• Since DIS is an IEEE standard, anyone can

have the standard and write an implementation.

Server-Side Support

• Information sent and received from a web server

• Centralized data allows for• Data Control• Analysis and Experimentation• Multiple AUV and sytems data integration

Web-based Mission Replay

AUV Mission Replay in 3D

XML-based Tactical Chat (XTC)

• Chat has emerged as an important method for tactical communications, but…

• Commercial Chat clients not entirely appropriate for military environments

• Proprietary formats are inscrutable

• Commercial Chat clients do not conform to NMCI (DoN)

XML-based Tactical Chat

• Both data transmitted and protocols of XML-based Tactical Chat can be examined

• Images, sounds, text and video are possible

• Open standards – free to use, NMCI conformant

• Cross platform

Extensible Modeling and Simulation Framework (XMSF)

• Composable set of standards, profiles and recommended practices for web-based modeling & simulation (M&S)

• XMSF must enable simulations to interact directly and scalably over a highly distributed network

• Not be constrained by proprietary technology or legally encumbering patents

Conclusion

• Interoperability through open-standards

• Loosely coupled data

• Web-technologies

• Exemplars and Proof-of-concepts

Questions & Answers

When open source and open standards, combine with best e-business practices, every effort then becomes related, synergies are created and tasks that once seem daunting, become achievable.

For more information:

http://web.nps.navy.mil/~brutzman