This dataset contains drive 7 from the dataset nds_data.
Format
A tibble with 321 rows and 34 columns
- drive
integer, identifier for a drive; a drive is defined as the time between starting the car and turning it off again.
- time_utc
POSIXct time stamp for each observation in UTC
- time_cst
POSIXct time stamp for each observation in Central time
GPS-based measurements for each observation:
- gps_elevation
numeric, elevation above sea-level (in m)
- gps_heading
numeric, continuity-corrected direction of the car (in degrees with north at 0 degrees and increasing clockwise) as measured by GPS. The continuity correction takes the initial GPS heading and adds the cumulative sum of the changes in GPS heading for the subsequent observations.
- gps_fix
numeric, value specifying the adequacy of the GPS fix, where 0 = no fix, 1 = time only, 2 = 2D fix, 3 = 3D fix. A gps_fix of 3 is needed for good GPS data.
- gps_sats
integer, the number of satellites covering a position.
- gps_pdop
numeric, position dilution of precision, an overall GPS data quality measure (lower is better)
- gps_hdop
numeric, horizontal dilution of precision, a GPS quality measure for latitude/longitude data (lower is better)
- gps_vdop
numeric, vertical dilution of precision, a GPS quality measure for elevation data (lower is better)
- speed_mph
numeric, speed of the vehicle (in miles per hour)
- speed_source
character, the source of the reported speed, either "gps" or "obd"
- distance_miles
numeric, distance traveled during a drive (in miles)
Measurements by the on-board gyroscope:
- accel_x
numeric, measure of vehicle acceleration along the front-back (longitudinal) axis (in g)
- accel_y
numeric, measure of vehicle acceleration along the right-left (lateral) axis (in g)
- accel_z
numeric, measure of acceleration of the vehicle in the up-down plane (normal/yaw axis) (in g)
- accel_event
numeric, sequential (over time) variable marking when consecutive acceleration values (absolute value of accel_x/y) exceed a threshold of 0.35g for a minimum of 1 second
- accel_event_cat
character, severity categorization of acceleration event into low (0.35-0.44g), medium (0.45-0.59g), and high (>0.6g)
- gyro_x
numeric, angular rotation rate about the right-to-left axis (in degrees/sec)
- gyro_y
numeric, angular rotation rate about the forward-to-backward axis (in degrees/sec)
- gyro_z
numeric, angular rotation rate about the up-to-down axis (in degrees/sec)
- gyro_heading
numeric, calculated heading utilizing compass data and gyro data (in degrees with north at 0 degrees and increasing clockwise). Note that we use non-standard congruence classes for continuity of consecutive values. Due to errors in the raw gyro heading, we use the initial GPS heading value as the initial heading value and then subtract the cumulative sum of gyro_z for the subsequent observations to calculate gyro_heading.
- grav_x
numeric, lateral gravity (in g)
- grav_y
numeric, longitudinal gravity (in g)
- grav_z
numeric, gravity (up-down) (in g)
- roll
numeric, angle about the forward-to-backward axis. 0 = level, positive = tilted to the left (in degrees)
- pitch
numeric, angle about the left-to-right axis where 0 = level, positive = tilted downward (i.e., vehicle going downhill) (in degrees)
- engine_rpm
numeric, current engine revolutions per minute value
- engine_throttle
numeric, engine throttle as a percentage (0-100%)
- cumulative_drive_dist_mi
numeric, the cumulative distance driven in miles at each observation
- gps_minute
factor, the minute component of the timestamp for each observation (00 to 59)
Raw heading measurements:
- gps_heading_raw
numeric, raw GPS heading without continuity correction (in degrees)
- gyro_heading_raw
numeric, raw gyro heading without continuity correction (in degrees)
GPS coordinates in a simple features column:
- geometry
list-column, simple features geometry column with geometry type POINT and CRS WGS84