ISAT User Guide Table of Contents

Who should use this document

This document is for users learning to use the NADS Interactive Scenario Authoring Tool (ISAT) to create scenarios for simulation.

This user guide contains an introduction to the ISAT interface and how to use ISAT for various tasks during the creation of scenario files (also known as scenario authoring).

Examples are provided to help illustrate concepts and tasks.

ISAT Overview & Interface Basics

This section contains interface documentation.

What is ISAT?

ISAT is the NADS Interactive Scenario Authoring Tool. ISAT is used to create simulation scenarios:

• 2D roadmap viewer
• Native file format: SCN (scenario.scn)

Requires a roadmap (BLI)

ISAT is NOT:

ISAT is not an object editor for creating or modifying 3D model objects, signs or roads.

miniSim Scenario Components*

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• See the NADS miniSim user guide for miniSim simulator architecture details (needs hyperlink here)

What is a Scenario?

A scenario defines everything that happens to the driver during a simulation.

Uses Actions and events to control the scenario; i.e., familiarization or restart drive, hazard detection & recognition or obstacle avoidance.

• Coupled to a roadmap (BLI)
• Scenario behaviors run at 30Hz

Anatomy of a Scenario

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Scenario files are text files

• Can be edited by a text editor
• Portions of a scenario file can be generated programmatically:
  • ISAT ISC
  • Python
  • Shell script

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Scenario Text File

Typically you can borrow elements from other scenario files

• If editing text,always check your edits in ISAT!
• Copy/Paste - delete paths from elements when the BLI is different between your source & destination BLI files:

ADO, roadpad, time to arrival, etc.

Traffic Source is not a portable element

Re-create it in ISAT or integrate it via text file

Text file is easy to examine in a command (shell) window.

Example search for time trigger in all scenario files: >grep TimeTrigger *.scn | grep ISAT | grep Name <Enter>

ISAT-Samples-Avoid.scn: Name "TimeTrigger1"

ISAT-Samples-Avoid.scn: Name "TimeTrigger2"

ISAT-Samples-Avoid.scn: Name "TimeTrigger3"

ISAT-Samples-Avoid.scn: Name "TimeTrigger1"

How to know what to look for in the scenario text file?

• Create a new scenario
• Create the scenario element you need or are looking for:

ADO, Trigger/Coordinator

Give the element a unique name that you can search for in the text file

• Save the file, then edit the file in a text editor

Find the element name to see element syntax and parameters

TBC: Insert demonstration to find an expression trigger that relates to the speed of the ownship

What is a Scenario Event?

A scenario event is made from one or more actions created to present situational information to the external driver (research participant, trainee or simulation viewer) in some logical sequence;

force a vehicle to change speed

force a vehicle to brake, change lanes or turn

create or destroy scenario elements

Or:

change scenario elements:

initialize variables

change traffic signal state

etc.

Typical Events

• When the external driver approaches a specified location, cause oncoming traffic to veer into the drivers' lane to force a driver response
• As the external driver approaches a specified location, control ambient traffic to expose a vehicle stopped in the drivers' lane
• When the Time to Arrival (to a specified location) is 4 seconds, change the traffic signal to yellow and activate traffic stopped at the intersection (aka red light runner)

What is an Action?

Actions are specific commands that happen intentionally during a simulation:

• Time, situational, calculation or location based
• Caused by the external driver or some other action, hardware configuration or calculation

can create or delete objects, including other scenario elements

Typically actions are linked with other actions to create a scenario event.

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Typical Actions

• Activate a scenario element
• Calculate something:

Time to arrival (TTA)

Time to collision (TTC)

headway

• Check state of simulator or driver
• Create something (any scenario element)
• Destroy a scenario element
• End simulation (terminates the current drive)
• Play a sound
• Set a variable
• Set ADO vehicle speed (not the external driver)

ISAT Modes of Operation

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• Edit
• Rehearsal
• DAQ playback
• Monitor Currently not available

Edit & Rehearsal Modes

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• Edit

Creation of scenario

Link to or import portions of other scenario elements

• Rehearsal

Debug & test scenario

Simulates scenario using Behaviors and Vehicle Dynamics

Displays error messages from behaviors

Playback Mode

• Playback mode will play back a DAQ file from a miniSim drive
• Can search for specific conditions; i.e. CFS_Brake_Pedal_Force > 0.1
• Display data streams
• Graph collected data (limited to single cells)
• Record a video file of the playback

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miniSim Scenario Components

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ISAT Workspace

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ISAT Workspace Accessing Elements

Accessing elements using the interface

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ISAT Workspace Status Bar

The status bar contains useful information to the scenario author:

• position (location of the cursor)

When configured:

• Name of scenario elements
• Roadway information:

road name

default speed limit

surface material code for location under the cursor

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ISAT Workspace Status Bar

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Measuring Distance in ISAT

To measure between two locations in ISAT:

• measurement is a linear measurement

Press & hold Ctrl and Shift keys, RMB on roadmap/BLI Position cursor over any other location

The measurement will update dynamically to reflect the distance from the cursor to the original 'pinned' location.

TBC link to video example

Scenario Authoring & miniSim Architecture Overview

This section contains scenario authoring documentation.

Terminology & Documentation

This section contains scenario authoring documentation.

Scenario Authoring Concepts

This section contains scenario authoring information.

Reporting ISAT & Scenario Issues

This section contains recommended procedures for reporting problems with ISAT or scenario authoring.

ISAT Reference Manual

TBC link to isat reference