[Code of Federal Regulations]
[Title 49, Volume 6]
[Revised as of October 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR563.5]

[Page 166-169]
 
                        TITLE 49--TRANSPORTATION
 
                   CHAPTER V--NATIONAL HIGHWAY TRAFFIC
                    SAFETY ADMINISTRATION, DEPARTMENT
                            OF TRANSPORTATION
 
PART 563_EVENT DATA RECORDERS--Table of Contents
 
Sec.  563.5  Definitions.

    (a) Motor vehicle safety standard definitions. Unless otherwise 
indicated, all terms that are used in this part and are defined in the 
Motor Vehicle Safety Standards, part 571 of this subchapter, are used as 
defined therein.
    (b) Other definitions.
    ABS activity means the anti-lock brake system (ABS) is actively 
controlling the vehicle's brakes.
    Air bag warning lamp status means whether the warning lamp required 
by FMVSS No. 208 is on or off.
    Capture means the process of buffering EDR data in a temporary, 
volatile storage medium where it is continuously updated at regular time 
intervals.
    Delta-V, lateral means the cumulative change in velocity, as 
recorded by the EDR of the vehicle, along the lateral axis, starting 
from crash time zero and ending at 0.25 seconds, and recorded every 0.01 
seconds.
    Delta-V, longitudinal means the cumulative change in velocity, as 
recorded by the EDR of the vehicle, along the longitudinal axis, 
starting from crash time zero and ending at 0.25 seconds, recorded every 
0.01 seconds.
    Deployment time, frontal air bag means (for both driver and right 
front passenger) the elapsed time from crash time zero to the deployment 
command or for multi-staged air bag systems, the deployment command for 
the first stage.
    Disposal means the deployment command of the second (or higher, if 
present) stage of a frontal air bag for

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the purpose of disposing the propellant from the air bag device.
    End of event time means the moment at which the cumulative delta-V 
within a 20 ms time period becomes 0.8 km/h (0.5 mph) or less.
    Engine RPM means, for vehicles powered by internal combustion 
engines, the number of revolutions per minute of the main crankshaft of 
the vehicle's engine, and for vehicles not powered by internal 
combustion engines, the number of revolutions per minute of the motor 
shaft at the point at which it enters the vehicle transmission gearbox.
    Engine throttle, percent full means the driver requested 
acceleration as measured by the throttle position sensor on the 
accelerator pedal compared to the fully depressed position.
    Event means a crash or other physical occurrence that causes the 
trigger threshold to be met or exceeded.
    Event data recorder (EDR) means a device or function in a vehicle 
that records the vehicle's dynamic, time-series data during the time 
period just prior to a crash event (e.g., vehicle speed vs. time) or 
during a crash event (e.g., delta-V vs. time), intended for retrieval 
after the crash event. For the purposes of this definition, the event 
data do not include audio and video data.
    Frontal air bag means an inflatable restraint system that requires 
no action by vehicle occupants and is used to meet the applicable 
frontal crash protection requirements of FMVSS No. 208.
    Ignition cycle, crash means the number (count) of power cycles 
applied to the recording device at the time when the crash event 
occurred since the first use of the EDR.
    Ignition cycle download means the number (count) of power cycles 
applied to the recording device at the time when the data was downloaded 
since the first use of the EDR.
    Lateral acceleration means the component of the vector acceleration 
of a point in the vehicle in the y-direction. The lateral acceleration 
is positive from left to right, from the perspective of the driver when 
seated in the vehicle facing the direction of forward vehicle travel.
    Longitudinal acceleration means the component of the vector 
acceleration of a point in the vehicle in the x-direction. The 
longitudinal acceleration is positive in the direction of forward 
vehicle travel.
    Maximum delta-V, lateral means the maximum value of the cumulative 
change in velocity, as recorded by the EDR, of the vehicle along the 
lateral axis, starting from crash time zero and ending at 0.3 seconds.
    Maximum delta-V, longitudinal means the maximum value of the 
cumulative change in velocity, as recorded by the EDR, of the vehicle 
along the longitudinal axis, starting from crash time zero and ending at 
0.3 seconds.
    Multi-event crash means the occurrence of 2 events, the first and 
last of which begin not more than 5 seconds apart.
    Non-volatile memory means the memory reserved for maintaining 
recorded EDR data in a semi-permanent fashion. Data recorded in non-
volatile memory is retained after a loss of power and can be retrieved 
with EDR data extraction tools and methods.
    Normal acceleration means the component of the vector acceleration 
of a point in the vehicle in the z-direction. The normal acceleration is 
positive in a downward direction and is zero when the accelerometer is 
at rest.
    Occupant position classification means the classification indicating 
that the seating posture of a front outboard occupant (both driver and 
right front passenger) is determined as being out-of-position.
    Occupant size classification means, for right front passenger, the 
classification of an occupant as an adult and not a child, and for 
driver, the classification of the driver as not being of small stature.
    Pretensioner means a device that is activated by a vehicle's crash 
sensing system and removes slack from a vehicle safety belt system.
    Record means the process of saving captured EDR data into a non-
volatile device for subsequent retrieval.
    Safety belt status means the feedback from the safety system that is 
used to determine than an occupant's safety belt (for both driver and 
right front passenger) is fastened or not fastened.

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    Seat track position switch, foremost, status means the status of the 
switch that is installed to detect whether the seat is moved to a 
forward position.
    Service brake, on and off means the status of the device that is 
installed in or connected to the brake pedal system to detect whether 
the pedal was pressed. The device can include the brake pedal switch or 
other driver-operated service brake control.
    Side air bag means any inflatable occupant restraint device that is 
mounted to the seat or side structure of the vehicle interior, and that 
is designed to deploy in a side impact crash to help mitigate occupant 
injury and/or ejection.
    Side curtain/tube air bag means any inflatable occupant restraint 
device that is mounted to the side structure of the vehicle interior, 
and that is designed to deploy in a side impact crash or rollover and to 
help mitigate occupant injury and/or ejection.
    Speed, vehicle indicated means the vehicle speed indicated by a 
manufacturer-designated subsystem designed to indicate the vehicle's 
ground travel speed during vehicle operation.
    Stability control means any device that is not directly controlled 
by the operator (e.g., steering or brakes) and is intended to prevent 
loss of vehicle control by sensing, interpreting, and adjusting a 
vehicle's driving and handling characteristics, is controlling or 
assisting the driver in controlling the vehicle.
    Steering wheel angle means the angular displacement of the steering 
wheel measured from the straight-ahead position (position corresponding 
to zero average steer angle of a pair of steered wheels).
    Suppression switch status means the status of the switch indicating 
whether an air bag suppression system is on or off.
    Time from event 1 to 2 means the elapsed time from time zero of the 
first event to time zero of the second event.
    Time, maximum delta-V, longitudinal means the time from crash time 
zero to the point where the maximum value of the cumulative change in 
velocity is found, as recorded by the EDR, along the longitudinal axis.
    Time to deploy, pretensioner means the elapsed time from crash time 
zero to the deployment command for the safety belt pretensioner (for 
both driver and right front passenger).
    Time to deploy, side air bag/curtain means the elapsed time from 
crash time zero to the deployment command for a side air bag or a side 
curtain/tube air bag (for both driver and right front passenger).
    Time to first stage means the elapsed time between time zero and the 
time when the first stage of a frontal air bag is commanded to fire.
    Time to maximum delta-V, lateral means time from crash time zero to 
the point where the maximum value of the cumulative change in velocity 
is found, as recorded by the EDR, along the lateral axis.
    Time to nth stage means the elapsed time from the crash 
time zero to the deployment command for the nth stage of a frontal air 
bag (for both driver and right front passenger).
    Time zero means for systems with ``wake-up'' air bag control 
systems, the time occupant restraint control algorithm is activated; for 
continuously running algorithms, the first point in the interval where a 
longitudinal, cumulative delta-V of over 0.8 km/h (0.5 mph) is reached 
within a 20 ms time period; or for vehicles that record ``delta-V, 
lateral,'' the first point in the interval where a lateral, cumulative 
delta-V of over 0.8 km/h (0.5 mph) is reached within a 5 ms time period.
    Trigger threshold means a change in vehicle velocity, in the 
longitudinal direction, that equals or exceeds 8 km/h within a 150 ms 
interval. For vehicles that record ``delta-V, lateral,'' trigger 
threshold means a change in vehicle velocity, in either the longitudinal 
or lateral direction that equals or exceeds 8 km/h within a 150 ms 
interval.
    Vehicle roll angle means the angle between the vehicle y-axis and 
the ground plane.
    Volatile memory means the memory reserved for buffering of captured 
EDR data. The memory is not capable of retaining data in a semi-
permanent fashion. Data captured in a volatile memory is continuously 
overwritten and is not retained in the event of a power

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loss or retrievable with EDR data extraction tools.
    X-direction means in the direction of the vehicle X-axis, which is 
parallel to the vehicle's longitudinal centerline. The X-direction is 
positive in the direction of forward vehicle travel.
    Y-direction means in the direction of the vehicle Y-axis, which is 
perpendicular to its X-axis and in the same horizontal plane as that 
axis. The Y-direction is positive from left to right, from the 
perspective of the driver when seated in the vehicle facing the 
direction of forward vehicle travel.
    Z-direction means in the direction of the vehicle Z-axis, which is 
perpendicular to the X- and Y-axes. The Z-direction is positive in a 
downward direction.