detecting aacn communications during crash tests · sae government industry meeting | january...

SAE Government Industry Meeting | January 25-27, 2017SAE Government Industry Meeting | January 25-27, 2017

Detecting AACN

Communications

During Crash Tests

John Martin

SAE Government Industry Meeting | January 25-27, 2017

Agency Goals

• Agency goal was to understand how we might objectively evaluate AACN

system performance

• NHTSA undertook research to establish a test procedure that could be

used for this purpose

• NHTSA defined general system/performance requirements, then

established a detailed protocol for evaluation

2


General Requirements

• An AACN equipped vehicle should automatically establish communication

with a telematics service provider (TSP) or public safety answering point

(PSAP) after a crash test without intervention by an outside agent

3


AACN Information Required from the Test

• Detection of communication between a crash test vehicle and the telematics service provider (TSP)

– An indication that the crashed vehicle is in communication with the public safety answering point (PSAP) or telematics service provider (TSP) after the crash

– Independent verification of RF transmission from the vehicle

• RF detection and recording device

• The contents of the crash data transmitted to the TSP or PSAP

– An indication of the contents of the crash data transmitted to the TSP PSAP

– Independently obtaining the contents of this data is not possible, assuming secure communication between the vehicle and the TSP or between the vehicle and the PSAP

• Ask the TSP or PSAP for the data or a subset of the data they receive, in one example, OnStar did provide information on an NCAP crash test

4


RF Detector for Crash Tests

5

0 20 40 60 80 100 120 140 160 180 2000

0.5

1

1.5

2

2.5

X: 29.89

Y: 2.5

OnStar Call 2/11/2016

2016 Chevy Malibu

Voltage

Time (seconds)

HiBand

LowBand

Trigger

AACN Call

Ends (86.38 sec)

AACN Call

Begins

(35.15 sec)

Recording

Trigger

(29.89 sec)



6

• Goal is to deliver an indication of a transmitted signal’s power to a data acquisition system

• Must be able to survive a crash test



7

• Earlier version



8

• Piggy-backed NCAP tests

revealed weak voltage

regulation circuitry

– Two frontal, one side

• One failure to take data for

reasons unknown

• Frequency of actual crash

tests not high enough for

verification purposes

• Series of sled tests


RF Detector Sled Testing

9

Channel Name <Min Value> <Max Value>

Vel

oci

ty [

mi/

h]

Time [ms]Filter Class: CFC 180

at

Time [ms]

Acc

eler

atio

n [

g]

at

at

at

-50 0 50 100 150 200 250 300 350

-40

-35

-30

-25

-20

-15

-10

-5

0

5

-50 0 50 100 150 200 250 300 350-40

-35

-30

-25

-20

-15

-10

-5

0

Duration = 78.26 ms

Pre

liminar

y

Sled Test #S161005-1 Pulse

TRC Inc. Test Lab: SLEDCustomer: VRTC

Test Number: S161005-1 Pulse

Date: 10/05/2016

Time: 12:25

-35.62 g 42.72 ms 0.78 g 94.88 ms

-37.88 mi/h 77.76 ms 0.00 mi/h 0.00 ms

S0SLEDCY0000ACXD

S0SLEDCY0000VEXC

S0SLEDCY0000ACXD

S0SLEDCY0000VEXC

Filter Class: CFC_60

Out of five 35 G, 38mph sled tests with a variety of orientations, two minor failures,

no structural failures of circuitry



10

• Later version shown here

• Developed in conjunction with TRC, but

MGA Research Corporation and Calspan

are building similar RF detectors using

the draft AACN test procedure… lessons

learned will be wrapped back into the

AACN test procedure


[email protected]

11

Thank You


[email protected]

12

Backup Slides



13

• RF Detection Circuit Internals



14


ZX60-V62+Amplifier

ZX60-H242+Amplifier

ZX47-40LN-SPower Detector

ZX47-40LN-SPower Detector

VBF-1840+Band-Pass Filter1750-1930 MHz

VBFZ-925-S+ Band-Pass Filter800 – 1050 MHz

Peak Analog Micromod 1

Neo Fire 2

ZAPD-2DC-S+

RF Splitter

Data Acquisition



15




16



17


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Part Number Description Manufacturer

VBF-1840+ Band-Pass Filter Mini-Circuits

VBFZ-925-S+ Band-Pass Filter Mini-Circuits

ZX60-V62+ RF Amplifier Mini-Circuits

ZX60-H242+ RF Amplifier Mini-Circuits

ZX47-40LN-S RF Power Detector Mini-Circuits

ZAPD-2DC-S+ RF Power Splitter Mini-Circuits

LM317 Voltage Regulator Various

LM7805C Voltage Regulator Various

TG.10.0113 Cellular Antenna Taoglas Antenna Solutions

Neo VI Fire CAN Logger Intrepid Controls Systems

Inc.

MicroMod Analog 1 Analog to CAN

Converter

Peak-System


19


20

Sled Test Device Orientations

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