A UAV Test and Development Environment Based on Dynamic System - - PowerPoint PPT Presentation

A UAV Test and Development Environment Based on Dynamic System Reconfiguration

Osamah A. Rawashdeh, Garrett D. Chandler, and James E. Lumpp, Jr. Department of Electrical and Computer Engineering University of Kentucky Lexington, KY

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Intelligent Dependable Embedded Architectures Lab University of Kentucky

Outline

• Motivation/Background
• Design Framework
• Runtime Behavior
• UAV Test and Development

Environment

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Intelligent Dependable Embedded Architectures Lab University of Kentucky

UAV Research at UK

• BIG BLUE: Baseline

Inflatable-wing Glider, Balloon- Launched Unmanned Experiment.

• Ongoing project at UK to

developing a test bed for Mars airplane technology.

• BIG BLUE is funded by

NASA and KSGC

• ~ 40 students involved

per year.

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Intelligent Dependable Embedded Architectures Lab University of Kentucky

Framework

• Software is developed in a modular fashion.
• Software modules can have several implementations with

different resource requirements and output qualities.

• Dependencies among modules are captured in

dependency graphs (DGs).

• Modules are scheduled on an interconnected set of

processing resources.

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Intelligent Dependable Embedded Architectures Lab University of Kentucky

Framework (cont.)

• Fault detection:

– By application code – Heartbeat messages – OS detected violations

• A system manager tracks status of

hardware and software resources.

• Fault handling: system is dynamically

reconfigured by deploying a new mapping

• f software modules to hardware

resources.

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Intelligent Dependable Embedded Architectures Lab University of Kentucky

System Architecture

– System Manager

• Tracks status of

resources

• Finds and deploys

configurations

– Processing Elements

• Host I/O hardware
• Real-time OS schedules

modules

– Communication Bus

• CAN 2.0 standard
• Control messages
• Data transfer

– Sensors and Actuators

Bus System Manager Processing Element Processing Element Processing Element Processing Element

Sensor Sensor Actuator Actuator Actuator Sensor

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Intelligent Dependable Embedded Architectures Lab University of Kentucky

Dependency Graphs

• DGs show the flow of information

from sensors to actuators.

• DG nodes:

– Software modules

Executable code schedulable on a processing element.

– Data variables

Inputs and outputs of software modules. State variables are local to a software module.

– I/O devices

Interface to the environment.

Output Device Software module Input Device

Data Variable

m Software module V1 Software module V2 Software module V3

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Intelligent Dependable Embedded Architectures Lab University of Kentucky

Data Requirements

• Dependency symbols:

– “k-out-of-n” gates: n > 0, 0 ≤ k ≤ n. – “XOR”: only one input required. – “DEMUX”: for fanning out. – “AND”: all input required.

• Quality values are associated

with variables.

Sensor Driver Sensor Sensor reading Actuator Actuator Driver Computing Module Actuator setting

k/n

a b c a b c a x y z x x a b c x

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Intelligent Dependable Embedded Architectures Lab University of Kentucky

Example Graph

Chute release Release cmd

Altitude (Quality2)

High quality altitude estimator

Altitude (Quality1)

Chute driver Chute Release Solenoid Chute logic 0/2 Low quality altitude estimator

Absolute pressure GPS altitude

• Abs. pressure

sensor Sensor driver GPS GPS driver

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Intelligent Dependable Embedded Architectures Lab University of Kentucky

Runtime Behavior

• Local

management tasks:

– Scheduler – Network Interface – Module Loader

• Module I/O data

passed through mailboxes.

• Data routing is

transparent to Modules.

Memory Loader

(low priority)

Schedule

(high priority)

CAN Bus Network Interface Next elevator angle Elevator Control Servo 1 driver Chute logic Low Qual. Altitude Est. “inputs” Release cmd Chute release Altitude (Q2) state info Messages to System Manager

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Intelligent Dependable Embedded Architectures Lab University of Kentucky

Current Research

• Expand bus via

wireless link to the ground:

– Rapid prototyping – Minimize risk to hardware – Flexible Reconfiguration

• Applying the

framework to the design of BIG BLUE IV

`1

Autopilot

Wireless Link

Sensors Mission Payload Interface

Wireless Link Aircraft Simulator

Actuator Interface Mission Control Resource Manager Experimental Autopilot

Mission Payload I/O

Flight Data Analysis

Pilot-in-the-loop