MAKE TO INNOVATEMid-Term Review – Spring 2019

MADS-B

AGENDA

Project Overview

Activity Report

• Design Constraints

• Current Design

• Design Risks

Design Review

Budget Status

Conclusion

PROJECT OVERVIEWProject Executive Summary

PROJECT OVERVIEW

(From Left to Right)

Back row: Thomas Smeed, Corey Johnson, Colin Firth, Tyler Johnson

Front row: Grant Jensen, Shashwini-Nair Krishnan, Matthew Rief, Max Van de Wille

Make to Innovate (M:2:I) FALL 2019

Project Photo

PROJECT OVERVIEW

FALL 2018Make to Innovate (M:2:I)

Project Stake

HoldersCollins Aerospace

Project Team Lead

Max Van de Wille – Software Engineering

Project Technical Advisers

Shaun Humes, Ankur Mehta – Collins Aerospace

Project Faculty Adviser

Matthew Nelson

PROJECT OVERVIEW

Project Organization Chart

Team Leader

Max Van de Wille

Integration Team Lead

Grant Jensen

Integration/Regulation

Thomas Smeed

Shashwini-Nair Krishnan

Embedded Team Lead

Corey Johnson

Embedded Systems

Matthew Rief

Colin Firth

Tyler Johnson

Project Plan

Project Objectives

• To create ADS-B capable transponder usable with UAS

• To enhance UAS integration into the national airspace

Semester Goals

• Complete transmitter

• Rework receiver with dump1090

• Begin basic integration with PixHawk PX4

Semester Deliverables

• ADS-B capable transmitter

• ADS-B receiver using dump1090

• Script to extract info from dump1090

ACTIVITY REPORTMilestones, Tasks, and Health Report

MILESTONES

Integration Team

1. Research on Pixhawk and dump1090 and install of dump1090

2. Procure and decode data from the receiver into a usable format (for autopilot system)

MILESTONES

Embedded Systems Team

Using Raspberry Pi/LimeSDR system create a working ADS-B Out system. This includes:

1.Receive all necessary data in real-time (mainly GPS)

2.Restructure data into ADS-B message format

3.Transmit all necessary ADS-B messages simultaneously

TASK BREAKDOWN

PROJECT HEALTH REPORT

Embedded Systems Transmission – LimeSDR issues

Integration PixHawk research

Real-time data retrieval from

GPS

DESIGN REVIEWOverview

DESIGN OVERVIEW – EMBEDDED

• Transmission of the ADS-B messages can be accomplished by:

1. Using the Raspberry Pi as the computer

2. Running a Python script that receives, formats, and finally..

3. Tells the LimeSDR how and when to transmit

DESIGN OVERVIEW – EMBEDDED

• This is a screenshot

from the Pi running a

program called

GNURadio

• When executed,

GNURadio generates

a Python script

• We will use a similar

flowgraph to this to

achieve transmission

• Finally we will edit the

generated python

script to receive and

format data

DESIGN OVERVIEW – INTEGRATION

• ADS-B In rework

• This semester we are working on making a dump1090 based ADS-B In system.

• dump1090 is a Mode S ADS-B decoder run from the command line

• The output files from dump1090 are .json files that are output into dump1090’s data folder every second.

• Other requirements include a program that automatically runs dump1090, displays the data, and outputs it to .json files automatically

DESIGN REVIEW - INTEGRATION

• PixHawk 4 integration work

• Research into I/Os of the PixHawk 4 and eventual (probably not this semester though) testing of a hybrid ADS-B + PixHawk detect and avoid system

• Python script/code running on the Raspberry Pi to translate dump1090 output to instructions for the autopilot.

DESIGN REVIEWConstraints

DESIGN CONSTRAINTSEmbedded Systems

• ADS-B message format

• 112 bits

• Data differs for each

Message

The 1090 MHz Riddle

DESIGN CONSTRAINTSEmbedded Systems

• Miscellaneous setbacks.

•'WestBridge' error – update interruption led to corruption in USB port connection

• Solution was to flash the correct image software into LimeSDR 'JX3'

•Lost microSD for Pi

• Had to re-install:

• the Ubuntu Mate OS on a new microSD

• GNURadio, LimeSuite

The 1090 MHz Riddle

DESIGN CONSTRAINTS

Integration/Regulation

• Minimal performance requirements from our programs so they will work on the Raspberry Pi

• We need powerful enough antenna to have adequate range for our receiver

• Quick response time for our programs (processes less than 2 seconds in total)

DESIGN REVIEWCurrent Design

CURRENT DESIGN - EMBEDDED

• Using the Pi as the computer running the GNURadio

generated python script

• Using the LimeSDR as the transmission device

DESIGN REVIEWProposed Changes

PROPOSED CHANGES – EMBEDDED

• Beginning the semester, we thought GNURadio could do all the operations necessary for transmission, but we realized we'd need:

1. Data from GPS and Aircraft Identification

2. Conversion of this data into ADS-B message format

• We decided we'll need to edit the GNURadio generated python script to accomplish these needs

PROPOSED CHANGES - INTEGRATION

• Dump978 could also be installed for easier 978 MHz coverage.

• The dump1090 version that we use could change based on performance and necessity.

• How we should code the scripts for use in our second milestone

DESIGN REVIEWDesign Risks

DESIGN RISKS

• Project faces inherent risks due to complex subject matter

• New members require onboarding process

DESIGN RISKS - EMBEDDED

• Power supply and cooling will have to be addressed – the Pi will be working with a complex python script running non-stop for extended periods of time

• Much of the work needs to be done during team meetings – any work done outside of team meeting depends solely on whoever has the equpiment

DESIGN RISKS - INTEGRATION

• Lack of programming knowledge on the integration team which could hinder our ability to progress on schedule

• Lack of usable hardware/dump1090 data for testing

• Compatibility issues

• Software troubleshooting

• General risks

BUDGETStatus and requests

BUDGET STATUS

• Will potentially be looking to purchase a PixHawk PX4 for use with Integration/Regulation team

Amount

Current Expenses $0

Estimated Expenses $70

BUDGET REQUESTS

• No formal budget requests currently

CONCLUSION

EXTRA SLIDES

EXTRA SLIDES

• ADS-B Message Structure

• Downlink Format (5 bits)

• For any ADS-B messages, the downlink format value must be 17, or 10001 in binary

• For any TIS-B or non-transponder systems, the downlink format value must be 18, or 10010 in binary

• Capability Address (3 bits) - The capability field acts as an additional identifier to previous format number, indicating the subtype of aircraft.

• ICAO Address (24 bits) - An essential message element, the ICAO address composed of 24 bits is used to identify the aircraft in a unique way

• Data Field (56)

• The type code identifies the information contained within the message

• Remaining bits contain message information

• Parity (24 bits) – Dedicated to the ADS-B cyclic redundancy check which will determine the validity of the message through 24 bits originating from the data field after it undergoes bitwise operation

EXTRA SLIDES

• Airborne Position Messages • Surface Position Messages

EXTRA SLIDES

• Velocity Messages • Identification Messages