Vehicle-to-Infrastructure Communication

ME302
“The Future of the Automobile”
Stanford University
Luca Delgrossi
May 6, 2014
Outline
 V2V Safety Applications
 USDOT V2V Safety Pilot
 V2I Safety Applications
 Intersection Collision Avoidance
 Integrated Safety Demo
V2V Safety Applications
5.9 GHz Spectrum
 Dedicated Short-Range Communications (DSRC)
Service
Channel
Service
Channel
Europe
1
2
HALL
Service
Channel
Service
Channel
Control
Channel
Service
Channel
Service
Channel
HPLR
172
174
176
178
180
182
184
USA
5.850 5.855
5.865
5.875
5.885
5.895
Frequency (GHz)
Reserved
Control
Channel
5.905
5.915
5.925
WAVE Protocol Stack
Safety
Applications
Non-Safety
Applications
Security
(IEEE 1609.2)
API
WME
(IEEE 1609.3)
UDP
WSMP
(IEEE 1609.3)
TCP
IP
LLC
MLME
WAVE upper MAC (IEEE 1609.4)
WAVE lower MAC (IEEE 802.11p)
PLME
WAVE PHY (IEEE 802.11p)
Design Challenges
 Reduce connection setup overhead
 Reduce hidden terminal effects
 Build trust among vehicles
 Common language
 Congestion control
 Privacy
V2
V1
V3
RTX
RCS
V2V Safety On-Board Equipment
GPS
Antenna
DSRC
Radio +
Antenna
GPS
Receiver
CAN
OBU
DVI
Initial V2V Applications
 Selection based on a ranking of crash scenarios considering
frequency, cost, and functional years lost.
 Emergency Electronic Brake Lights (EEBL) broadcasts “hard
braking” messages to surrounding vehicles. Vehicles use the
received messages to determine when it becomes necessary
to warn the driver.
 Forward Collision Warning (FCW) warns the driver of the
risk of a collision with a vehicle ahead in the same lane and
direction of travel.
 Blind Spot Warning (BSW) warns the driver when a blindspot zone is or is about to be occupied by another vehicle
traveling in the same direction.
Initial V2V Applications
 Do Not Pass Warning (DNPW) warns the driver during a
passing maneuver when a vehicle ahead and in the same lane
cannot be safely passed.
 Intersection Movement Assist (IMA) warns the driver when
it is not safe to enter an intersection due to high collision
probability with other vehicles.
 Control Loss Warning (CLW) broadcasts “control loss”
messages to surrounding vehicles. Vehicles used the received
messages to determine when it becomes necessary to inform
or warn the driver.
 OEMs joined forces at the Crash Avoidance Metrics
Partnership (CAMP) to implement these applications
Addressed Crash Scenarios
EEBL
FCW
BSW
DNPW
IMA

Lead Vehicle Stopped

Control Loss without Prior Vehicle Action
Vehicle(s) Turning at Non-Signalized Junctions

Straight Crossing Paths at Non-Signalized
Junctions

Lead Vehicle Decelerating


Vehicle(s) Not Making a Maneuver – Opposite
Direction
Vehicle(s) Changing Lanes – Same Direction
Left Turn Across Path/Opposite Direction at Non
Signalized Junctions
CLW



Concept of Operations
 The concept of operations for V2V safety applications
requires each vehicle to periodically broadcast safety
information in a standard format intelligible by
surrounding vehicles.
 A small set of information such as position, speed, heading,
brake status, and vehicle size is sufficient.
 This suggests that a common message set can support
multiple V2V safety applications as opposed to separate
messages for each safety application.
 The Basic Safety Message (BSM) was specified as part of the
DSRC Message Set standard [SAE J2735].
Data Dictionary
 SAE J2735 currently specifies 15 message types, of which




the BSM is one of the most prominent.
A BSM consists of data elements and data frames. A data
element is a basic building block and a data frame comprises
one or more data elements or other data frames.
Vehicles use data elements and data frames to compose BSMs
just as words in a dictionary are used to build sentences.
Other message types include Roadside Alert, Signal Phase
and Timing, Probe Vehicle Data, and Traveler Information.
Although SAE J2735 is intended for use over the DSRC
band, the message set definition is independent of the
spectrum and can be utilized in different contexts.
Basic Safety Message
 Special efforts made to minimize the message size.
 BSM Part I (Basic Vehicle State) is mandatory and
contains those data elements and data frames that must
always be included in a BSM (39 bytes).
 BSM Part II (Vehicle Safety Extension) includes
optional data elements and data frames. Part II data
elements and data frames are marked as optional.
 Part II is included in a BSM only when necessary. For
example, for specific events such as emergency braking.
 BSMs are transmitted in plain text because the
information is meant to be seen by all receivers.
Basic Safety Message
BSM Data Item
Type
Bytes
Part
Message ID
E
1
I
Message Count
E
1
Temporary ID
E
Time
BSM Data Item
Type
Bytes
Part
Heading
E
2
I
I
Steering Wheel Angle
E
1
I
4
I
Accelerations
F
7
I
E
2
I
Brake System Status
F
2
I
Latitude
E
4
I
Vehicle Size
F
3
I
Longitude
E
4
I
Event Flags (opt)
E
2
II
Elevation
E
2
I
Path History (opt)
F
Var.
II
Positioning
Accuracy
Transmission &
Speed
F
4
I
Path Prediction (opt)
F
3
II
F
2
I
RTCM Package (opt)
F
Var.
II
Minimum Performance Requirements
 SAE is currently developing Minimum Performance
Requirements to specify BSM data accuracy, broadcast
frequency, and transmission power [SAEJ2945].
 SAE J2945 is expected to specify how frequently BSMs
should be broadcast.
 This choice is a trade-off between long inter-packet delays
experienced by V2V safety applications and heavy wireless
channel utilization.
 It is generally accepted among experts that broadcasting at 10
Hz is sufficient for the most demanding V2V safety
applications (upper limit)
Target Classification
Intersecting Left
Intersecting Right
IMA
Ahead
Ahead Left
Ahead Right
FCW
CLW
Behind
Behind Left
Behind Right
EEBL
BSW
Oncoming
Oncoming Left
Oncoming Right
DNPW
Path History & Prediction
vehicle center
width
antenna
length
Emergency Electronic Brake Lights
Host Vehicle
Remote Vehicle
Intersection Movement Assist
Remote Vehicle
Intersection Point
Host Vehicle
V2V Positioning
 Primary focus is to establish the relative position
 Importantly, no maps are used in the described V2V
applications
 Two positioning methods: a) Lat-Lon reported by two
vehicles, and b) GPS raw data and Real-Time Kinematic
(RTK) positioning
DSRC
DSRC
U.S. DOT Initiatives
Alameda Point, CA
(Jan 2012)
Michigan
International
Speedway
Brooklyn, MI
(Aug 2011)
Brainerd International
Raceway
Brainerd, MN (Sept 2011)
VTTI Smart Road
Blacksburg, VA
(Nov 2011)
Texas
Motor Speedway
Fort Worth, TX
(Dec 2011)
Walt Disney World
Speedway
Orlando, FL (Oct 2011)
Driver Acceptance Clinics

Ann Arbor, MI

2800+ Equipped Vehicles

1 Year Duration
V2V Model Deployment
Test Driving in California
Shipping Vehicles to Michigan
Preliminary Results
I2V Safety Applications
Intersection Crashes
 Crashes occurring within the limits of an intersection and as
vehicles approach or exit an intersection account for about
1.72 million crashes and 9,000 deaths every year in the U.S.
 In 2004, stop sign and traffic signal violations accounted for
302,000 crashes resulting in 163,000 functional life years
lost and $7.9 billion of economic loss.
 About 250,000 of those accidents involved vehicles running a
red light and colliding with another vehicle crossing the
intersection from a lateral direction. These accidents led to
$6.6 billion in economic cost in the U.S.
CICAS-V
 Cooperative Intersection Collision Avoidance System for
Violations (CICAS-V) was a joint effort by the USDOT and a
consortium of five automotive OEMs (Ford, General
Motors, Mercedes-Benz, Toyota and Honda) under the Crash
Avoidance Metrics Partnership (CAMP) framework.
 The goal of CICAS-V systems is to improve safety at
intersections.
 CICAS-V was a groundbreaking project because it
demonstrated the first V2I prototype safety system based on
DSRC ready for a field operation trial (FOT) in the United
States.
CICAS-V Concept of Operations
 The system relies on DSRC to exchange safety messages in
real time between a RSU installed at an intersection and an
OBU installed on the vehicle.
 The OBU monitors vehicle dynamics, position, lane of travel,
and distance to the stop line. It assesses the risk of violating
intersection signals, and warns the driver of imminent danger
if a violation is predicted.
CICAS-V Concept of Operations
 The information included in these messages comprises
current Signal Phase and Timing (SPAT) for the local traffic
signal controller and digital map of the local intersection
called Geometric Intersection Description (GID).
 The OBU determines the probability of a violation by
continuously assessing the vehicle speed, SPAT, and the
vehicle’s distance from the stop bar in the lane of travel.
 The OBU issues a warning to the driver if it predicts that,
given the current operating conditions, the vehicle is going to
violate the signal to enter the intersection.
CICAS-V Hardware
CICAS-V Software
CICAS-V Positioning
5th Ave & El Camino Real (Atherton)
Integrated Safety Demo
Integrated Safety Demonstration
Advisory
Comfortable
Stop
Advisory
Indicates a potential red
light violation
Escalated Warning
Hard
Stop
Warning
Alerts driver urging to
take an action
Pre-Crash
Automatic
Stop
Automatic Stop
Activate active safety (MB
Pre-safe®)
Driver Vehicle Interface
Driver Vehicle Interface
System Components Overview
Trafiic
Light
Camera
Emergency
Power shutoff
Integrated DSRC
& GPS Antenna
Seat Position
Adjusted
(Pre-Safe)
Seat Belt
Tensioners
(Pre-Safe)
Windows
rolled up
(Pre-Safe)
Unlocked ESP
for high G
braking with
model
predictive
control
Patch Panel for
power, CAN
access, etc.
Onboard PC to
run application
and interface
with radio, HMI,
GPS, CANlog etc.
Isolated ESP
for activating
Pre-Safe
Differential GPS
with Kalman
Filtering for
positioning
Head Unit
and RSE
Displays
Camera for
live offboard
video
streaming
Isolated RDU
unit to activate
braking
Antenna & router
for off-board HMI
& video display
Cable harness for
CAN access
GPS antenna
signal splitter
Image processing
for HMI & Camera
display

Download Report